Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Tomoyuki Kanda

Yoshimichi Tsubata

Eiji Suzuki

Eiji Ohyama

Takao Sato

Masaaki Yamaguchi

Atsushi Fujikawa

Daihei Teshima

Naoki Uchiyama

Keiichi Hanyu

Katsuyuki Narai

Tamotsu Kotegawa

Akinori Tanno

A transmission equipped with a continuously variable ratio-change mechanism CVT and a LOW rotational transmission mechanism GT, which are disposed parallel with each other, comprises a forward clutchand a reverse brake, which are used to set a power transmission through the continuously variable ratio-change mechanism, a LOW clutch, which is used to set a power transmission through the LOW rotational transmission mechanism, and a control unit ECU and a hydraulic control valve HV, which control the engagement of the clutches and the brake. When the transmission is switched from its neutral mode to its in-gear mode, at first, the forward clutchis brought gradually into engagement, and then it is released before the LOW clutchis brought into engagement in a squat control.

Vehicular transmission

In a power transmission system in a vehicle including a continuously variable gear path and a multi-stage gear path, a difference between gear ratios at the start of forward travel and at the start of backward travel is minimized, while using a single-pinion type planetary gear mechanism. The continuously variable gear path includes a forward/backward travel switching mechanism comprising a single-pinion type planetary gear mechanism, and a belt-type continuously variable transmission. A multi-stage gear path comprising gears is set at a gear ratio closer to a LOW side from that of the belt-type continuously variable transmission. Thus, when the forward traveling and the backward traveling are switched over from one to another, it is unnecessary to suddenly change the gear ratio of the belt-type continuously variable transmission, which can contribute to an improvement in durability of belt-type continuously variable transmission.

Power transmission system in vehicle

In a control apparatus for an automotive continuously variable transmission having a forward-reverse selector mechanism in which a gear ratio for reverse is set closer to a speed reducing side than a gear ratio for forward and a belt type continuously variable transmission mechanism, a PH pressure that is outputted from a first regulator valve and a PL pressure that is outputted from a second regulator valve are changeably supplied to one and the other of a hydraulic cylinder of a drive pulley and a hydraulic cylinder of a driven pulley via a shift control valve. A hydraulic pressure supplied to a reversing hydraulic pressure connecting element from a reversing manual valve is inputted into an oil chamber of a first regulator valve so that the PH pressure is increased with the hydraulic pressure so inputted.

Control apparatus for an automotive continuously variable transmission

A lubrication pressure controller comprises a lubrication pressure regulating valve,, which is provided in a lubrication oil passage,directing hydraulic oil to lubricated parts, and a cooler pressure regulating valve,, which is provided in a discharge oil passage,of the lubrication pressure regulating valve,. The lubrication pressure regulating valve,adjusts the pressure in the lubrication oil passage,, and the cooler pressure regulating valve,adjusts the pressure supplied to an oil cooler,. The hydraulic oil discharged from the cooler pressure regulating valve,is returned through a recirculation line,to a suction oil passage,of a pump. In this construction, an adequate supply of lubrication oil is maintained even if one of the valves experiences locking of a valve spool on an open side. Moreover, by providing signal pressure generating means,, which applies a signal pressure to these two valves in correspondence with a driving condition, the lubrication pressure controller can be set to acquire a desired balance in the lubrication, cooling and recirculation for the hydraulic oil in response to a driving condition.

Lubrication pressure controller

In a chamber R,which accommodates a transmission device comprising a drive pulley,, a driven pulley,and a belt,, a cover,is provided to cover the lower peripheral portion of the drive pulley,along the periphery. The drive pulley is positioned below the driven pulley, and raised portions,which are used for the detection of the rotational speed of the drive pulley are provided on the periphery of the drive pulley. The end surface,of the cover facing the inner wall,of the pulley chamber is positioned away from the inner wall with a clearance V therebetween. In a vehicular transmission which is constructed in this arrangement, the amount of lubrication oil that flows near to the periphery of the pulley which is positioned lower is comparatively small. Thus, this arrangement restricts agitation of the lubrication oil, which may be caused by the raised portions of the rotating pulley. Therefore, loss in the rotation of the pulley and oxidation and degradation of the lubrication oil are effectively prevented.

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Wako, Japan

Tomoyuki Kanda