| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a valve device for an internal combustion engine being a caulking method which suppresses a crack of a crushed portion 43 by increasing a caulking amount and can secure a strong coupling force.SOLUTION: When coupling a shaft 12 of a throttle valve 11 and a valve gear 18 by caulking means, an annular guide part 52 is arranged around a molding punch (caulking punch) 50, a caulking solid shaft part 40 of the shaft 12 is crushed by the molding punch 50, and when a crushed portion 43 is caulked (made to bite in) to a fitting recess 42 of the valve gear 18, a maximum extension deployment region (maximum expanded diameter D1) of the crushed portion 43 is regulated by an internal peripheral face 53 of the guide part 52. By this constitution, the generation of a crack at the crushed portion 43 is prevented, and a coupling force (caulking strength) can be raised.SELECTED DRAWING: Figure 4 |
