Abstract: A friction plate has a plurality of friction material segments circularly fixed on an annular core plate, wherein each of the friction material segments includes an oil groove having an opening that opens in the direction of an outer circumferential edge of the friction plate and an end portion that ends between an inner circumferential edge and the outer circumferential edge, oil passages in communication in the direction of the inner and the outer circumferential edges of the friction plate are provided among the friction material segments, and at least some of the oil passages have a first shape, the width of which in a circumferential direction decreases from the inner circumferential edge of the friction plate toward the outer circumferential edge thereof.

Abstract: The present invention provides a friction plate that takes more air into a lubricating oil on a friction surface so as to reduce the shear resistance force of the lubricating oil interposed between friction materials, thereby achieving significantly reduced drag torque at the time of idling, as compared with a conventional friction plate, and a wet-type multiple-disc clutch provided with the friction plate.

Abstract: A friction plate for a wet-type multiplate clutch provided with a core plate and friction linings fixed on opposite sides of the core plate, respectively. Each of the friction linings is formed such that at a section thereof located on a side radially inner than a radial center line thereof, the friction lining has a thickness that gradually increases from an inner circumferential portion of the section toward an outer circumferential portion of the section.

Abstract: In a lockup clutch assembly for use in a torque converter, a friction lining attached to one of a clutch piston and a front cover of the torque converter is divided into an outer-circumference-side friction lining and an inner-circumference-side friction lining. The outer-circumference-side friction lining contains as a filler diatomaceous earth in a higher proportion than the inner-circumference-side friction lining.

Abstract: In a torque converter equipped with a lock-up clutch device, a friction member is put on either one of a front cover and a lock-up piston which are to be brought into contact. On the front cover, coupling members are welded for coupling with an engine. Owing to welding distortion, convex portions are generated on a friction face. Thus, when the friction member is put on either side of the front cover and clutch piston, if relative rotation slippage occurs therebetween, a positive pressure and a negative pressure are produced in front of and behind each convex portion, which leads to the stick/slip. This invention gives grooves 71 each exceeding the range of a welding portion 61 of the coupling member 6 which are formed on the friction face of the friction member 7, which realizes balancing in a change in pressure.

Abstract: In a wet type friction plate having a groove through which lubricating oil passes, the groove is subjected to oil repelling treatment.

Abstract: In a lockup clutch assembly for use in a torque converter, a friction lining attached to one of a clutch piston and a front cover of the torque converter is divided into an outer-circumference-side friction lining and an inner-circumference-side friction lining. The outer-circumference-side friction lining contains as a filler diatomaceous earth in a higher proportion than the inner-circumference-side friction lining.

Abstract: A friction plate for a wet-type multiplate clutch provided with a core plate and friction linings fixed on opposite sides of the core plate, respectively. Each of the friction linings is formed such that at a section thereof located on a side radially inner than a radial center line thereof, the friction lining has a thickness that gradually increases from an inner circumferential portion of the section toward an outer circumferential portion of the section.

Abstract: A wet type friction plate comprises symmetrical segments cut out of a frictional member, and pasted on the metallic core plate so as to form a groove which is gradually narrower from the inner diameter side to the outer diameter side. A method of producing the wet type friction plate, comprising the steps of cutting symmetrical segments out of a frictional member, and pasting the cut-out symmetrical segments on a metallic core plate so as to form a groove which is gradually narrower from the inner diameter side to the outer diameter side.

Abstract: A wet friction material is mainly composed of a fiber base material, a filler, an friction adjusting agent and a thermosetting resin. The wet frictional material is prepared by impregnating with a liquid thermosetting resin a paper formed by mixing a paper-forming solid thermosetting resin with a fiber base material as at least a part of filler, and then applying heat to the paper so that it is hardened. The solid thermosetting resin is preferably a phenol resin. The liquid thermosetting resin is preferably made of a silicone resin represented by the following average composition formula and the amount of trifunctional unit monomers (RSiO3/2 in which R represents a substituted or unsubstituted monovalent hydrocarbon group) in monomers constituting said silicone resin is from 40 to 100 mol-%: (R1)a(OR2)bSiO(4−a−b)/2.

Abstract: A wet frictional material having a high heat resistance, excellent durability and superior initial conformability. The wet frictional material contains a fiber base material, a filler, a frictional adjustment agent and a thermosetting synthetic resin. The thermosetting synthetic resin comprises a silicone resin represented by the following average formula. The silicone resin contains a trifunctional unit (RSiO.sub.3/2) (where R represents a substituted or unsubstituted monovalent hydrocarbon group) in an amount of from 40 to 100 mol % of units constituting the silicone resin:(R.sup.1).sub.a (OR.sup.2).sub.b SiO.sub.(4-a-b)/2where R.sup.1 represents a substituted or unsubstituted monovalent hydrocarbon group, and R.sup.2 represents a hydrogen atom or an organic group having from 1 to 10 carbon atoms, and 0.2.ltoreq.a.ltoreq.1.8 and 0<b.ltoreq.1.0).