The invention discloses a high-precision
involute spline broach and a design method thereof. The high-precision
involute spline broach comprises a calendaring guide
tooth part, wherein the calendaringguide
tooth part comprises a plurality of calendaring guide tooth rings that are concentrically arranged, the calendaring guide tooth rings are used for guiding a workpiece, and each calendaring guide tooth ring comprises a plurality of calendaring guide teeth that are annularly distributed; the outer
diameter of a first tooth of the calendaring guide tooth is DY1, and DY1 is equal to D0l-
delta;the outer
diameter of the last calendaring guide tooth is DYN, wherein DYN=DYN+phi / 2, the
tooth number NY of the calendaring guide tooth, and NY is equal to [(DYN-DY1) / fy]; D0l is the lower differenceof the hole before drawing of the workpiece, D0[mu] is the upper difference of the hole before drawing of the workpiece,
delta is a guide gap, phi is a
roundness error of the hole before drawing of the workpiece, fy is the tooth rise amount of the press polish guide teeth, and [] represents the nearby
rounding of the result. According to a
synchronizer thin-wall part machined by the structure, the procedure percent of pass is greatly increased, the
machining quality of a workpiece is guaranteed, and meanwhile, due to separation of a rough
broaching procedure and a fine
broaching procedure, rough
cutting teeth do not participate in final tooth profile forming, so that the
cutting allowance of fine
broaching teeth is small, and the service life of a broach is prolonged.