| 摘要 |
A movable board provided with movable contact points 54 is arranged inside a switch case 3 formed by overlap of a substrate 10 provided with fixed contact points 20 and a lid body 35. A top end surface of the substrate 10 is provided with a concave streak portion 47e and a ring groove 30 for accommodating a seal ring 31, wherein a projecting streak portion 40 provided on a lower surface of a flange portion 38 in the lid body 35 is fitted in the concave streak portion 47e for welding. A seal bearing 47 mounted to shaft holes 15 provided on an opposing portion between the substrate 10 and the lid body 35 comprises a cylindrical body portion 47a fitted in at least one of the shaft holes 15, and a lip-shaped seal portion 47b extending to a side of a rotary surface of a shaft portion from an inner peripheral surface of the body portion 47a to make flexible contact with the rotary surface. An air in the switch case 3 is discharged to an outside (atmosphere) by the seal portion 47b flexibly deflected by a negative pressure through the shaft hole. |
