Grinding flow-guiding device suitable for grinding high-injection-pressure injection nozzle needle valve and grinding method

Abstract

The invention discloses a grinding flow-guiding device suitable for grinding a high-injection-pressure injection nozzle needle valve. The grinding flow-guiding device comprises a locating pin and a flow guiding rod connected with the locating pin. The locating pin is arranged in a cavity of the injection nozzle needle valve to limit movement of the flow guiding rod, and the head of the flow guiding rod is located at an injection hole inlet of the injection nozzle needle valve to shield the circular bead on the lower half part of the injection hole inlet. A grinding method includes the steps of primary conventional grinding, secondary grinding conducted after installation of the grinding flow-guiding device, and re-grinding conducted after removal of the grinding flow-guiding device. According to the injection nozzle needle valve ground by the grinding flow-guiding device through the grinding method, at the aspect of injection nozzle performance, flow loss in an injection nozzle is further reduced, the flow coefficient is remarkably increased, the probability of cavitation erosion of an injection hole under high injection pressure is lowered, and the service life of the injection nozzle under the high injection pressure is prolonged. At the aspect of a process, the grinding time of the needle valve is prolonged, and the situation that according to a conventional grinding method, with increasing of the grinding time, the overall grinding degree of the injection hole inlet of the needle valve is improved, and interference between the injection holes occurs too early is avoided.

Description

technical field [0001] The invention belongs to the technical field of fuel injector processing, in particular to a grinding guide device suitable for grinding a needle valve body of a high injection pressure fuel injection nozzle. Background technique [0002] At present, the common principle of liquid extrusion grinding of needle valve body is as follows: Image 6 shown. The needle valve body is clamped by the clamping cylinder, and the high-pressure abrasive enters the middle hole of the processed fuel injection nozzle from the clamp, and returns to the collection box through the pressure chamber and the spray hole. Under the action of high pressure, the abrasive generates a certain pressure and cutting abrasive flow on the nozzle hole and pressure chamber of the fuel injector, thereby micro-grinding the pressure chamber of the needle valve body, the corner burrs and the surface of the nozzle hole. Through grinding, a rounded corner of a certain size is formed in the tra...

AI Technical Summary

Problems solved by technology

The main methods known to increase the amount of grinding include increasing the processing pressure and prolonging the processing time. However, the conventional extrusion grinding process is limited by the domestic processing equipment and level. If the processing pressure is too high or the time is too long, it is easy to cause extrusion deformation of the nozzle hole. , the highest flow coefficient can only reach about 0.8

On the other hand, at present, it is mainly judged whether the extrusion grinding is qualified by detecting the flow coefficient of the needle valve body, and the shape of the extrusion hole entrance fillet cannot be controlled.

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