PURPOSE: To maintain a high friction coefficient without impairing a cooling effect in a wet friction plate, which is used while a cooling fluid is supplied to the friction surface, by forming a plurality of grooves on the friction surface at a prescribed interval.
CONSTITUTION: A friction plate 1 is used while it is maintained in a wet condition by the oil such as a fluid for an automatic transmission. Fine grains are sticked to the surfaces (both front and reverse sides) of a base plate 2 of the friction plate 1 through an adhesive means such as plating or brazing, so that a friction layer 3 is formed by these fine grains. Multiple stripes of oil grooves 4, which open at the front side of the friction layer 3, are formed on the friction layer 3. The pitch of these oil grooves 4 is less than 1.2mm. In addition, the width of these oil grooves is made narrower than that of a part of the friction layer 3, which is held between the oil grooves 4. With this, excessive oil, which forms a film in a sliding condition, can be eliminated by the oil grooves 4, and it can be restricted or prevented that the oil is drawn out of the oil grooves 3 to form a film on the friction surface.
SUGIHARA KOICHI
TAKETSUNA YASUHARU
MAEDA TOMOYUKI
Next Patent: MANUFACTURE OF WET FRICTION PLATE