Patent ID: 6382883
Filing Date: 2002-05-07
Classification: B23C,F01B,F02F,Y10T

Abstract:
A method for lapping a valve seat of a plurality of pre-existing valve seats with corresponding valve guides in an engine cylinder head utilizing a spindle assembly in a machining apparatus, the spindle assembly having a spindle adapted for rotation around a vertical axis, the method comprising:providing a carriage head at a lower portion of the spindle assembly, the carriage head having a carriage head control mechanism for effecting radial feed of the carriage head relative to the vertical axis; attaching a universal cutting tool to the carriage head, the universal cutting tool having a single cutting point; attaching a pilot at the lower portion of the spindle assembly so that the pilot is centered on the vertical axis, wherein the pilot is adapted to fit within a valve guide; centering the spindle assembly with respect to the valve seat by inserting the pilot into the valve guide corresponding to the valve seat; providing lapping parameters for a desired valve seat profile to a system controller, the desired valve seat profile comprising a plurality of segments, each segment having a segment length and at least one segment angle; in the system controller, using the segment length and at least one segment angle for each of the plurality of segments to calculate each of a carriage head feed rate of the carriage head and a vertical feed rate and rotational speed of the spindle for lapping each segment of the valve seat profile using the lapping parameters; and separately for each segment of the desired valve seat profile, generating control signals in the system controller for controlling the vertical feed rate and the rotational speed of the spindle and controlling the carriage head feed rate independent of the vertical feed rate and the rotational speed.