Aisin Kako Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Takuya Muranaka

Masato Suzuki

Hirofumi Onishi

Yuko Higashijima

Takatora Sugiura

Ryouhei Hoshino

In a wet friction material, inorganic filler of small particle size is added to fill clearances or space between fibers with the inorganic filler. The inorganic filler is attached to the fibers with each other to reinforce strength of the wet friction material when an impregnated resin is hardened. Absolute specific gravity of the inorganic filler is set at a fixed value so as to make its compounding quantity small, thereby assuring a pore diameter of a friction material substrate without filling pores of the friction material substrate with the inorganic filler.

Wet friction material including an inorganic filler

Three external tooth wet friction materials are each composed of an external tooth plate and a lining adhered to one surface thereof along an entire circumference. Three internal tooth wet friction materials are each composed of an internal tooth plate and a lining adhered to one surface thereof along an entire circumference. Then, the three external tooth wet friction materials and the three internal tooth wet friction materials are disposed side by side so as to constitute a multi-plate frictional engagement apparatus. A thickness of the internal tooth plate is made thinner in view of its good heat discharge capability, and the thickness of the external tooth plate is made thicker by that much.

Multi-plate frictional engagement apparatus

In a segment-type wet friction material, an inner peripheral left corner of one segment piece and an inner peripheral right corner of another segment piece are respectively cut off at a fixed angle to a center line of an oil groove. The oil grooves have first oil grooves and second oil grooves. The second oil groove has nearly a uniform width. The first oil groove has an inner peripheral corner portion that is broadened to the center line of the oil groove from a fixed height. In case of being assembled in an automatic transmission, when the segment-type friction material rotates in one direction, an automatic transmission fluid supplied from an inner circumference bumps and touches the portion that is broadened at the fixed angle at a rear side in the rotating direction.

Growing community of inventors

Aichi-gun, Japan

Takuya Muranaka