| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power steering device that can be used in a severe environment by enhancing drainage and sealability of a rack housing.SOLUTION: A drainage system 100 comprises: a drain case 110; and a drain valve 160. The drain case 110 includes a groove part 138 at a peripheral edge of an inner surface 132a of a case inlet 132, and the drain valve 160 includes a body part 161 and a flange part 162 formed at one end of the body part 161 and disposed opposing to the case inlet 132. The flange part 162 includes: a raised part 170 having a shape raised toward the case inlet 132 at the center; and an annular seal part 171 located at the peripheral edge. By making the seal part 171 come into close contact with the peripheral edge of the inner surface 132a of the case inlet 132, a valve close state is produced. By forming an annular space 139 between the groove part 138 and the seal part 171 and forming a clearance between the seal part 171 and the peripheral edge of the inner surface 132a of the case inlet 132 due to elastic deformation of the seal part 171, a valve open state is produced. |
