Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Kenichi Namerikawa

Shigeru Kanehara

Ukyo Ogata

Hiroyuki Kushiyama

A power transmission apparatus includes a continuously variable transmission, a clutch, a drive condition determination device, an input torque calculator, a belt transfer torque calculator, and a clutch transfer torque controller. The continuously variable transmission includes a drive pulley, a driven pulley, and a belt. The clutch transfer torque controller controls a transfer torque of the clutch so that the transfer torque of the clutch is higher than or equal to an input torque calculated by the input torque calculator and is lower than a transfer torque of the belt calculated by the belt transfer torque calculator if it is determined that the vehicle is under a drive condition.

Power transmission apparatus and method for controlling power transmission apparatus

A process for presuming a power-transmitted state in a metal belt-type continuously variable transmission and for controlling axial thrust in a metal belt-type continuously variable transmission wherein it is presumed that a vector sum of friction coefficients .mu..sub.TDN and .mu..sub.RDN of a driven pulley is 0.1; a friction coefficient .mu..sub.RDR of a drive pulley is 0, and a friction coefficient .mu..sub.SDR or .mu..sub.SDN of the one of the pulleys which has a smaller winding radius is 0.1. A speed ratio i, a number N.sub.IN of rotations of the drive pulley, an input torque T.sub.IN to the drive pulley and an axial thrust Q.sub.DN of the driven pulley are measured, and the measured values are introduced into relational equations of the balance of forces on various portions of a metal belt-type continuously variable transmission. In this manner, an axial thrust Q.sub.DR of the drive pulley, urging forces E.sub.1 and E.sub.2 between the blocks and the pulleys, an axis-axis force FS, ring tensions T.sub.1 and T.sub.2, a friction coefficient .mu..sub.TDR, a friction coefficient .mu..sub.TDN, a friction coefficient .mu..sub.RDN, and a friction coefficient .mu..sub.SDR or .mu..sub.SDN of the one of the pulleys which has a larger winding diameter can be calculated from the relational equations. Thus, a power-transmitted state such as the friction coefficient can be presumed without actual generation of a slipping between a metal belt and a pulley of the metal belt-type continuously variable transmission.

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Wako, Japan

Kenichi Namerikawa