| 摘要 |
In a clutch plate of an annular shape and a wet type, a plurality of lubrication grooves each taking a U-shape in cross-section are formed on a friction engaging surface on at least one end side. The groove is provided with a groove forming portion crossing the circumferential direction and blunt portions extending along both sides of the groove forming portion and connecting the friction engaging surface with the groove forming portion. Where a straight line passing across one side end of the groove and extending in a radial direction is assumed as a virtual straight line, in a section of the groove taken along a plane that is orthogonal to the virtual straight line and that includes the one side end, the width of the blunt portion on one side is in a range of 0.12 to 0.35 mm, and the depth of the blunt portion is in a range of 25 to 50 μm. |
