| Project/Area Number |
60850137
|
|---|
| Research Category |
Grant-in-Aid for Developmental Scientific Research
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
溶接工学
|
|---|
| Research Institution | Osaka University |
|---|
Principal Investigator |
KIMIYUKI NISHiGUCHI Faculty of Engineering, Osaka University, 工学部, 教授 (50028940)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
KIN-ICHI MATSUYAMA Faculty of Engineering, Osaka University, 工学部, 助手 (80029305)
|
|---|
| Project Period (FY) |
1985 – 1987
|
| Project Status |
Completed (Fiscal Year 1987)
|
| Budget Amount *help |
¥13,200,000 (Direct Cost: ¥13,200,000)
Fiscal Year 1987: ¥6,000,000 (Direct Cost: ¥6,000,000)
Fiscal Year 1986: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1985: ¥5,200,000 (Direct Cost: ¥5,200,000)
|
|---|
| Keywords | Spor welding / High strength steel sheets / Resistance welding / Misfit type parts / Firness of plates at faying surface / 分流電流 |
|---|
| Research Abstract |
This project was organized to develop a new system to improve the weldability in spot welding of pressed high strrangth steel sheets of misfit type which are usually used in automobile industry. The inverstigation was achieved fivided into three points of material of plate, desing of welding machine and welding process.
As the results, follwing conclusions are obtained;
1) They are effextive to increase shunting current to the pre-spot welds and to improve the surface smoothness of workpieces to suppress the influence of misfit at the faying surface on spot welding of high sterngth steel sheets.
2) The low spot weldbility in spot welding of high strength steel sheets with mistitness is caused by discrete ring-like contact at the fabying surface.
3) It is effective to use direct current powert source instead of usual A. C. power source to increase the weldable current tange defined by critical expulsion current fro higher side and critical nuggent formation one for lower side.
4) If a slope-up control of electrode of force is achieved synchtonized in current slope-up in welding start duration in each spot welding, the welbable current ragne wide even with A.C. type spot welder, 5) Suitable inverter frequency defined by wider weldble current range is less than 1kHz for above 0.6mm thickness stee. sheets.
|
