Analysis on the problems of irregular step hole on horizontal machining center

Usually we process the step blank hole , It is completed by using the fine boring fixed cycle function of the horizontal machining center . But this only applies to regular step holes , For the step blank hole on the above complex casting , Because the position deviation of the hole is irregular , And irregular , This makes it impossible to determine the deflection angle of the tool tip when the boring tool is fed axially , It will cause cutting when feeding , Even if you don't cut while feeding , It will also cause rapid damage to the tool due to unilateral cutting during boring due to the position deviation of the hole , Therefore, it is not suitable to use the function of conventional fine boring cycle on the horizontal machining center to process the above irregular step empty tool holes .

　　 Use a single edge boring cutter with a radius smaller than the radius of the empty hole , While the spindle tool rotates , Boring with soft cut spiral feed , The turning radius of boring tool tip is r, Spindle boring cutter rotates , Fast feed along the center line of the step hole to as shown in the attached figure b The rightmost end of the empty tool hole shown , Then the boring tool is used to （R-r）/2 The semicircle with radius is the radial soft cut of the tool center motion path, as shown in the attached figure c The hole wall at the right end of the empty tool hole shown , Then the boring tool starts from z The rightmost empty knife hole wall is marked with （R-r） The semicircle of the radius is the motion path of the tool center , Take the center line of the step hole as the axis , Make spiral interpolation and feed boring , That is, while the tool rotates , The machine tool makes two axis linkage , That is to say, the tool rotates and moves radially and axially at the same time , When the boring cutter spiral interpolation feed is as shown in the attached figure b At the leftmost end of the empty tool hole shown , The tool is （R-r）/2 It is a semicircle of radius, and it is the motion path of the tool center to soft cut the empty tool hole wall , Make the central axis of the tool return to the central axis of the step hole , Then the tool is quickly retracted axially , This completes the machining process of an empty tool hole . This soft cutting method can avoid the cutting phenomenon caused by the position deviation of the hole ; Spiral interpolation feed boring , It can avoid the phenomenon of unilateral cutting and striking caused by the position deviation of the hole , It can also realize the function of boring large holes with a boring tool with small turning radius .