Patent UA-73092-U (UA)
Title: Multiblade cutting tool for drawing boring internal cylindrical surfaces
Inventor: KRYVYI PETRO DMYTROVYCH
IPC: B23B51/10
Filed: 2012-03-01
Abstract: A multiblade cutting tool, in a body of which four pairs of diametrically opposite located first relative to the third, and the second relative to the fourth, identical, parallel to the longitudinal axis of the tool, wedge-shaped grooves are made. Traces of the first lateral flat surfaces of each wedge-shaped groove in the plane perpendicular to the longitudinal axis of a tool is normal to the circle formed by the cross-section of the same plane of outer cylindrical surface of working part of the body. On other sides of wedge-shaped grooves located at an anglerelative to the respective first flat side surfaces of wedge-shaped grooves, which are less than the friction angle, corrugations are made which are inclined at an angle to the longitudinal axis of tool, which is determined by the formula:, where   - value of regrinding of the cutter in radial direction, mm;   - value of permissible radial wear of the tool, mm;- minimal value of regrinding of the tool holder on the front surface, mm.Central angles between the flat surfaces of first and second and third and fourth wedge-shaped grooves are the same and equal to. On the main cutting edges of cutting elements mounted in the first and second wedge-shaped grooves, in which the auxiliary angles in plan are the same, and makebevels are made at an angleto the longitudinal axis of tool. In the working part of body four diametrically opposed located identical, parallel to the longitudinal axis of a tool grooves of dovetail type are made in pairs. The position of one of them is defined in the plane perpendicular to the longitudinal axis of tool by a central angle formed by its axis and lateral flat surface of the first wedge-shaped groove, which is defined by the formula, whereb - maximum width of a dovetail groove, mm;B - the maximum width of a wedge-shaped groove, mm;- radius of groove cavities, mm.The position of groove adjacent to it is determined in the plane perpendicular to the longitudinal axis of a tool by a central angle formed by its axis and flat side surface of the first wedge-shaped groove according to the formula, whereb - maximum width of a dovetail groove;- radius of the groove cavities.In the grooves elastic guides are installed that are displaced in the direction opposite to the feed with respect to the apexes of cutting elements for a certain value, and on which the bevels are made for their smooth introduction in a machined hole. On the cutting elements installed in the second and fourth wedge grooves the auxiliary angles are the same in plan, and, as on the cutting elements installed in the first and third wedge-shaped grooves they make. On the auxiliary cutting edges of cutting elementswide chamfers are made. On the main cutting edges of cutting elements mounted in the second and fourth wedge-shaped grooves the bevels are made at an angle to the longitudinal axis of the tool, which is determined by the formula:, where  - additional bevel angle of inclination to the longitudinal axis of tool in the first and second cutting elements, deg.;   - auxiliary angle in plan on cutting elements, deg.;- central angle between the flat surfaces of first and second and third and fourth wedge-shaped grooves, deg.