| 摘要 |
PURPOSE:To reduce tightening force for installation by providing a surface with a step in the shape of the cross section of the letter L having a circumferential groove on the inner circumference on the open end side of the outer part, and by pressing a circumference projecting streak of the cylinder-shaped extended wall outer circumferential surface provided continuously from the outer circumferential edge of a cover body plate part into this circumferential groove. CONSTITUTION:A cylindrical surface 21 having a circumferential groove and a surface with a step 23 made of a bumping surface 22 are provided on the inner circumference on the open end side of the outer 20, and a body plate part 31, a cylinder-shaped extended wall 32 with a circumference projecting streak 35 provided on its outer circumference and a boss part 33 are formed on a cover 30. Here, with plastic deformation by press of the extended wall 32 of the cover 30, the inner surface of the body plate part 31 is pressed on the bumping surface 22 of the outer 20. Accordingly, high sealing property can be secured on each pressed surface, tightening load by press is reduced, and miniaturization of a press device can be attempted. And production equipment cost is reduced and high quality with high centering accuracy can be obtained. |
