Nissan Motor Company Limited

Hiromasa Sakai

Motoharu Nishio

Takashi Murasugi

Hiroaki Kuramoto

Toshikazu Oshidari

Yasushi Narita

Hiroyuki Hirano

Nobutaka Takahashi

Jun Sugihara

Ikuhiro Taniguchi

Tatsuya Nagato

Kotaro Akashi

Kazuhiro Yamada

Masaki Nakano

Koichi Hayasaki

Taketoshi Kawabe

Shinichiro Joe

Hirofumi Shimizu

Masayuki Yasuoka

Kazuhiro Takatori

Itsuro Muramoto

Satoshi Sakakibara

Tsutomu Yamazaki

Chiaki Harada

Eio Sagara

Masayoshi Kimura

Toshikazu Oshidarai

Shin-ichiro Joe

Manzaburou Abe

A fuel cell system of the present invention includes: a fuel cell supplied with fuel gas and oxidizing gas to generate electricity; a fuel gas supply unit supplying the fuel gas to the fuel cell; an oxidizing gas supply unit supplying the oxidizing gas to the fuel cell; an aftercooler cooling the oxidizing gas supplied to the fuel cell by heat exchange with a coolant; an oxidizing gas temperature detector detecting temperature of the oxidizing gas; and a coolant circulation controller starting circulation of the coolant when the detected temperature of the oxidizing gas exceeds a predetermined value. The predetermined value is set to a value of not higher than a minimum electricity generation temperature of the fuel cell, and a circulation timing and flow rate of the coolant for the aftercooler are controlled such that the supplied oxidizing gas does not become cold. This enables the fuel cell to generate electricity at cold start-up.

Fuel cell system

A fuel cell system of the present invention includes: a fuel cell () supplied with fuel gas and oxidizing gas to generate electricity; a fuel gas supply unit supplying the fuel gas to the fuel cell (); an oxidizing gas supply unit supplying the oxidizing gas to the fuel cell (); an aftercooler () cooling the oxidizing gas supplied to the fuel cell () by heat exchange with a coolant; an oxidizing gas temperature detector () detecting temperature of the oxidizing gas; and a coolant circulation controller () starting circulation of the coolant when the detected temperature of the oxidizing gas exceeds a predetermined value. The predetermined value is set to a value of not higher than a minimum electricity generation temperature of the fuel cell (), and a circulation timing and flow rate of the coolant for the aftercooler () are controlled such that the supplied oxidizing gas does not become cold. This enables the fuel cell () to generate electricity at cold start-up.

A control device for a vehicular fuel cell system is provided with a warm-up output control section operative, when a fuel cell system is started up under a low temperature condition and in case that a fuel cell stack of the fuel cell system is warmed up, causing the fuel cell stack to generate electric power to allow predetermined warm-up electric power to be taken out, and a run permission section operative, during a period wherein the warm-up electric power is drawn by the warm-up output control section, to determine whether the fuel cell stack assumes a predetermined warm-up condition on the basis of one of a voltage value and an electric current value of the fuel cell stack. When a determination is made that the fuel cell stack assumes the predetermined warm-up condition, the run permission section provides a vehicle with run permission.

Control device of vehicular fuel cell system and related method

The fuel cell system comprises a fuel cell () that has an electrolyte membrane and generates power by using a fuel gas and an oxidizing agent gas; a storage device () for water that humidifies the fuel cell; and a controller (). The controller () judges whether the fuel cell () can be humidified by using the water of the storage device (), and limits the operating temperature of the fuel cell () to below a limit temperature that is lower than during normal operation in a case where it is judged that the fuel cell () cannot be humidified.

A fuel cell system has a fuel cell () performing power generation as a result of reactions in supplied gases, a humidifying device () for humidifying at least one supplied gas by using water from water tank (), and a coolant temperature regulation device () for regulating the temperature of the coolant flowing within the fuel cell () in order to control the temperature of the fuel cell (), and a defrosting device (). The defrosting device () melts ice in the water tank () during a startup operation of the fuel cell system by applying heat contained in the coolant to the ice. Here, the coolant has an increased temperature as a result of waste heat produced during power generation inside the fuel cell ().

A three-way clutch unit ( ) comprising a forward clutch ( ), second clutch ( ) and forward one way clutch ( ) which sets a power recirculation mode, a high clutch ( ) which sets a direct mode, and a mode change-over valve ( ) which supplies an oil pressure to one of the high clutch ( ) and second clutch ( ), are provided.

Infinite speed ratio continuously variable transmission

When an engine control unit ( ) controls an engine rotation speed Ne to an idle rotation speed, and a select range is changed over from a non-travel range to a travel range, a speed change control unit ( ) commands an increase of engine torque supplied to the engine control unit ( ), and increases the transmission torque of a continuously variable transmission ( ) according to the increase amount of the engine torque.

Drive force control system for vehicle with infinite speed ratio continuously variable transmission

In an infinitely variable transmission, a continuously variable transmission ( ) outputs the rotation of an input shaft ( ) at an arbitrary speed ratio, and a fixed speed ratio transmission ( ) outputs the rotation of the input shaft ( ) at a fixed speed ratio. A planetary gear set ( ) varies the rotation direction and speed of the output shaft ( ) according to the difference of the output rotation speed of the fixed speed ratio transmission ( ) and the output rotation speed of the continuously variable transmission ( ). A sensor ( ) which detects the rotation speed of the input shaft ( ) and a sensor ( ) which detects the output rotation speed of the continuously variable transmission ( ) are provided, and a microprocessor ( ) precisely calculates the rotation direction and rotation speed of the output shaft ( ) from these rotation speeds.

Control of infinitely variable transmission

An infinite Speed ratio continuously variable transmission comprises a power recirculation mode clutch ( ) and direct mode clutch ( ). At least one of the power recirculation mode clutch ( ) and direct mode clutch ( ) comprises an electromagnetic two-way clutch. The electromagnetic two-way clutch maintains the engaged state during excitation and can transmit drive force from both the drive side and non-drive side. On the other hand, when there is a change-over from the energized state to the non-energized state, a one-way clutch state is obtained wherein drive force is permitted only in the transmission direction of drive force in the instant of the change-over to non-excitation. When a drive force is input in the reverse direction to the drive force transmitted in the one-way clutch state, the one-way clutch state is disengaged, and the disengaged state of the clutch is maintained until subsequent re-excitation. Therefore, change-over of the clutch at the rotation synchronous point RSP where the power recirculation mode and direct mode are changed over, can be performed rapidly.

In an infinite speed ratio transmission, a rotation of an input shaft ( ) is input both to a continuously variable transmission ( ) and a fixed speed ratio transmission ( ). A CVT output shaft ( ) of the toroidal continuously variable transmission ( ) is joined to a sun gear ( A) of a planetary gear set ( ), an output shaft ( C) of the fixed speed ratio transmission ( ) is joined to a planet carrier ( B) of the planetary gear set ( ), and a vehicle is driven under the output of a ring gear ( C) of the planetary gear set ( ). A controller of the infinite speed ratio transmission comprises an actuator ( ) which varies an amount of torque transmitted between the input shaft ( ) and the CVT output shaft ( ). A microprocessor ( ) controls the actuator ( ) so that a torque in the opposite direction to the vehicle travel direction shown by a selection range of a selector lever ( ) is not transmitted by the continuously variable transmission ( ).

Speed change controller for infinite speed ratio transmission

A toroidal continuously variable transmission ( ) comprises power rollers ( C, D, C, D) which transmit a torque between input disks ( A, A) and output disks ( A, B), and trunnions ( ) which drive the power rollers ( C, D, C, D) in a perpendicular direction to a rotation shaft ( A) according to a differential pressure between a first oil chamber ( ) and a second oil chamber ( ). When the second oil chamber ( ) is at higher pressure than the first oil chamber ( ), the toroidal continuously variable transmission ( ) causes a downshift, and when the first oil chamber ( ) is at higher pressure than the second oil chamber ( ), the toroidal continuously variable transmission ( ) causes an upshift. The first oil chamber ( ) is connected to a first passage ( ) and the second oil chamber ( ) is connected to a second passage ( ). A speed ratio control valve ( A) controls a direction and a flowrate of the first passage ( ) and the second passage ( ). A pressure control valve ( ) limits a maximum differential pressure of the first oil chamber ( ) and the second oil chamber ( ) when the transmission ( ) causes a downshift to be less than a maximum differential pressure of the first oil chamber ( ) and the second oil chamber ( ) when the transmission ( ) causes an upshift. This arrangement prevents a sharp downshift of the toroidal continuously variable transmission ( ) due to a fault or incorrect operation.

Controller of toroidal continuously variable transmission

An output shaft ( ) of a continuously variable transmission ( ) is joined to a sun gear ( A) of a planetary gear mechanism ( ), and joined to a final output shaft ( ) via a direct mode clutch ( ). An output shaft ( C) of a fixed speed ratio transmission ( ) is joined to a planet carrier ( B) of the planetary gear mechanism ( ) via a power recirculation mode clutch ( ). Oil pressure supply to the direct mode clutch ( ) and power recirculation mode clutch ( ) is controlled by a controller ( ) via a mode fixing valve ( ). A cam ( ) which moves in synchronism with a trunnion ( ) of the continuously variable transmission ( ) locks the mode fixing valve ( ) in a position which shuts off oil supply to one of the clutches ( ), ( ) when the speed ratio of a continuously variable transmission ( ) is smaller than a predetermined value lcC, and releases the lock when the speed ratio of the continuously variable transmission ( ) is larger than the predetermined value lcC.

Clutch control device of infinite variable speed ratio transmission

An infinite speed ratio continuously variable transmission is provided with a continuously variable transmission ( ), fixed speed ratio transmission ( ), planetary gear set ( ), power recirculation clutch ( ) and direct clutch ( ). A target speed ratio of the infinite speed ratio continuously variable transmission is set based on a vehicle speed and an accelerator pedal depression amount. When the target speed ratio varies beyond a rotation synchronous point, a control unit ( ) assigns an order of priority to control of the power recirculation clutch ( ) and direct clutch ( ), and control of the speed ratio of the continuously variable transmission ( ), and thereby causes a real speed ratio of the infinite speed ratio continuously variable transmission to vary in the same direction until it reaches the target speed ratio (S , S , S , S , S , S ).

Speed change controller and control method of infinite speed ratio continuously variable transmission

In an infinite speed ratio transmission comprising a continuously variable transmission (,), reduction gear unit (,) and planetary gear set (,), the speed ratio of the continuously variable transmission (,) is controlled by a step motor (,). A range selected by a selector lever (,) is detected by a sensor (,). When the selected range has changed from a stationary range to one of a forward motion range and a reverse motion range, a microprocessor (,) first drives the step motor (,) to a predetermined position (S,, S,). Subsequently, by driving the step motor (,) to an operating position corresponding to a geared neutral point at which the output rotation speed of the infinite speed ratio transmission is zero (S,, S,, S,, S,, S,, S,), the undesirable effects of hysteresis occurring in a relation between the operating position of the step motor (,) and the speed ratio of the continuously variable transmission (,) according to a torque shift of the continuously variable transmission (,) are avoided.

Controller for infinite speed ratio transmission

A creep torque is controlled in a non-finite speed ratio transmission device, wherein a planetary gear unit (,) varies a rotation direction of a final output shaft (,) according to a relative rotation of a toroidal continuously variable transmission (,) and fixed speed ratio transmission (,). The controller comprises a hydraulic cylinder (,) which varies the speed ratio of the toroidal continuously variable transmission (,) by driving a trunnion (,), a shift control valve (,) which supplies a hydraulic pressure to the hydraulic cylinder (,) according to a displacement position, a step motor (,) which displaces the shift control valve (,) according to a command signal, and a mechanical feedback member (,) which feeds back the speed ratio of the toroidal continuously variable transmission (,) to the shift control valve (,). The controller further comprises a sensor (,) which detects a running state of a vehicle, a sensor (,) which detects the real speed ratio of the continuously variable transmission (,), and a microprocessor (,) which outputs the command signal. When the vehicle running state corresponds to a predetermined state, the microprocessor (,) outputs a new command signal based on a required creep torque and the real speed ratio of the continuously variable transmission (,) to the step motor (,).

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Yokosuka, Japan

Hiromasa Sakai