| 摘要 |
A set oil ring to be assembled into a piston ring groove is made up of a spacer ring and a pair of side rail rings to be placed on both sides thereof. In assembling one of the side rail rings into a first groove portion which is on an upper side of the spacer ring in the piston ring groove, a guide member, which can be moved up and down for fitting the rings onto a piston, is moved to a first fitting position which is substantially the same level as the groove wall surface of the first groove portion. A restricting member is disposed oppositely in front of the guide member while leaving a clearance facing the first groove portion. One of the side rail rings is pushed out of the front end of the guide member in a condition in which split end portions of the spacer ring are restricted by the restricting member so as not to overlap. In assembling the other of the side rail rings into a second groove portion, which is on the lower side of the spacer ring in the piston ring groove, the guide member is moved to a second fitting position in which the front end of the guide member becomes substantially equal in level to that surface of the spacer ring which is on the side of the second groove portion. The other of the side rail rings is pushed out of the front end of the guide member in a condition in which the split end portions of the spacer ring are restricted by an internal surface of the guide member so as not to overlap. |
