2003 Fiscal Year Final Research Report Summary
OPTIMIZATION OF CUTTING EDGE GEOMETRY OF DRILLS IN DRILLING DIFFICULT TO CUT MATERIALS
| Project/Area Number |
13650132
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
機械工作・生産工学
|
|---|
| Research Institution | SEIKEI UNIVERSITY |
|---|
Principal Investigator |
HIROTA Akihiko SEIKEI UNIVERSITY, FACULTY OF ENGINEERING, PROFESSOR, 工学部, 教授 (70016682)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KASAHARA Kazuo SEIKEI UNIVERSITY, FACULTY OF ENGINEERING, INSTRUCTOR, 工学部, 講師 (50169405)
|
|---|
| Project Period (FY) |
2001 – 2003
|
| Keywords | DIFFICULT TO CUT MATERIALS / DRILLING / NEGATIVE RAKE ANGLE / CHAMFER / DEAD METAL / CUTTING MODEL / CUTTIG FORCE / CHIP FORMATION |
|---|
| Research Abstract |
1.FOR CUTTING WITH LARGE NEGATIVE RAKE ANGLE TOOLS HAVING ARTIFICIALLY CONTROLLED TOOL-CHIP CONTACT LENGTH OR WITH THAT TOOLS HAVING NATURAL TOOL-CHIP CONTACT LENGTH, CUTTING MODELS IN WHICH THE MODE OF DEFORMATION IS APPROXIMATED WITH THE VELOCITY DISCONTINUITY LINES ARE DEVELOPED. THE CUTTING MODELS ARE ABLE TO EXPLAIN THE TRANSITION OF CHIP FORMATION PROCESS INVOLVING DEAD METAL ON THE PRIMARY RAKE FACE IN TWO MODELS. THE DEAD METAL ON THE RAKE FACE DOES NOT DISAPPEARED EVEN IN LOW FRICTIONAL CONDITION WHERE CUTTING FLUID IS SUPPLIED SUFFICIENTLY. IT IS FOUND THAT PREDICTED RESULTS ARE IN GOOD AGREEMENT WITH EXPERIMENTAL RESULTS.
2.FOR CUTTING WITH TOOLS HAVING THREE RAKE SURFACES, THAT IS, CHAMFERED EDGE AND SECONDARY RAKE FACE WITH ARTIFICIALLY CONTROLLED TOOL-CHIP CONTACT LENGTH, THREE-DIMENSIONAL OBLIQUE CUTTING MODEL CONSIDERING TRANSLATIONAL VELOCTY ALONG THE CUTTING EDGE IS DEVELOPED. EXPERIMENTS USING QUICK STOPPING DEVICE TO FREEZE THE CHIP FORMATION WERE MADE, AND IT IS FOUND THAT THE DEAD METAL CONTINUES TO EXIST IN THE RANGE OF 50° OF INCLINATION ANGLE.
3.BASED UPON THE DATA SUCH AS CUTTING FORCES OBTAINED THROUGH ENERGY METOD FOR DRILLING WITH FLAT RAKE FACE DRILL, CUTTING TEMPERATURE IS CALCULATED USING FINITE ELEMENT METHOD. FOR LONG-PITCH CHIP FORMATION IN DRILLING STAINLESS STEEL SUS304(JIS), HIGH TEMPERATURE REGIONS APPEAR IN OUTER PORTION CORRESPONDING TO MARGIN AND INNER PORTION OF THE MAIN CUTTING EDGE.
4.FOR DRILLING STAINLESS STEEL SUS304(JIS) WITH DRILLS OF HIGH SPEED STEEL OR SINTERED CARBIDE, IT IS FOUND FROM EXPERIMENT TO GIVE LONG TOOL LIFE THAT THE ADEQUATE CONDITION IS RAKE ANGLE OF CHAMFERED PORTION (PRIMARY RAKE ANGLE) ; -15 〜 -30°, PROJECTED LENGTH OF SECONDARY RAKE FACE ; 0.3〜O.7 TIMES FEED RATE(HIGH SPEED STEEL), 0.15〜0.3 TIMES FEED RATE(SINTERED CARBIDE) AND TOTAL PROJECTED TOOL-CHIP CONTACT LENGTH ; ABOUT 1.4 TIMES FEED RATE.
|
