Toyota Jidosha Kabushiki Kaisha

Toyota Motorsport Gmbh

Kabushiki Kaisha Toyota Chuo Kenkyusho

Aisin Ai Co., Ltd.

Jun Yabuta

Akihiko Ichikawa

Shinichi Takeuchi

Tomohiro Yoshimura

Lars Van Leeuwen

Klemens Pollmeier

Andree Miller

Tomomitsu Terakawa

Isamu Shiotsu

Kotaro Hoshihara

Patrizio Agostinelli

Tomoyasu Kurimoto

Junichi Muraoka

Yuuki Masui

Tadashi Kumagai

Yuki Masui

Takeshi Yano

A gear change control device according to an embodiment includes a detection unit configured to detect the gear stage of a transmission and measure the input rotation rate of the transmission and the rotation rate of an engine and a controller configured to decrease the torque of a clutch to a second reference value from a first reference value when a first time elapses from a time point at which the rotation rate of the engine and the input rotation rate of the transmission become different from each other due to a gear change from a certain gear stage to a gear stage one or a plurality of stages higher than the certain gear stage that is performed by the transmission.

Gear change control device

A control apparatus for a vehicular transmission including at least one dog clutch each having a first dog member mounted on a first shaft such that the first dog member is rotated together with the first shaft, and at least one second dog member each mounted to be axially adjacent to the first dog member and rotatable relative to the first shaft, first gears each mounted to be rotatable relative to the first shaft and provided with the second dog member, second gear which are mounted such that the second gears are rotated together with a second shaft parallel to the first shaft, and which mesh with the respective first gears, and a shifting mechanism for selectively placing each dog clutch in an engaged or released state. The control apparatus includes: a first calculating portion for detecting to a rotary angular position of the first shaft, and calculating a rotary angular position of the first dog member on the basis of the detected rotary angular position of the first shaft; a second calculating portion for detecting a rotary angular position of the second shaft, and calculating a rotary angular position of each second dog member on the basis of the detected rotary angular position of the second shaft; and an engagement control portion for controlling the shifting mechanism on the basis of the rotary angular positions of the first and second dog members, for engagement of the first and second dog members with each other.

Control apparatus for vehicular transmission

A dog clutch includes a gear () mounted on a power transmission shaft (), first and second dog rings (), a fork (), springs (), and cam grooves (). The cam grooves () each include a first slope surface () inclined from the axial direction toward the positive rotation direction as the first slope surface () approaches the gear () and a second parallel surface () parallel to the axial direction. The first dog ring () includes first cam protrusions () to be engaged with the respective first slope surfaces (), and the second dog ring () includes second cam protrusions () to be engaged with the respective second parallel surfaces (). This structure prevents the dog rings and the fork from coming into contact with each other, thereby avoiding generation of abrasion and increasing the transmission efficiency.

Dog clutch and transmission

A vehicle transmission has a plurality of gear positions that are to be selectively established, and includes: an input shaft; a first shaft; a second shaft; an output shaft; at least one first drive gear disposed on the first shaft; at least one second drive gear disposed on the second shaft; at least one driven gear disposed on the output shaft; a dog clutch connecting and disconnecting between the input shaft and each of the first and second shafts; and a synchronous meshing apparatus. The synchronous meshing apparatus connects and disconnects between each of the first and second shafts and the output shaft, and, when connecting between each of the first and second shafts and the output shaft, establishes a power transmission path from each of the first and second shafts to the output shaft via a selected one of the at least one first or second drive gear.

Vehicle transmission

A first dog ring and a second dog ring are biased toward each other by means of springs. When the first dog ring and the second dog ring are moved away from each other, bias force produced by the springs is applied to the second dog ring in a direction to draw the second dog ring toward the first dog ring. Accordingly, when the first dog ring is moved away from the second dog ring during shifting, the second dog ring is drawn toward the first dog ring under the bias force, and third engaging teeth of the second dog ring and meshing teeth of a first-speed gear are promptly disengaged from each other.

Transmission for vehicle

A control apparatus for a vehicle transmission that includes: transmission gears disposed on a shaft; a switching mechanism which is to be switched between a connecting state in which one of the transmission gears is rotatable integrally with the shaft and a disconnecting state in which the one of the transmission gears is rotatable relative to the shaft; a shift fork for axially moving the switching mechanism; and a shift barrel to be rotated to position the shift fork. The switching mechanism includes first and second rings and an elastic member which is disposed between the first and second rings in the axial direction and connects the first and second rings. The control apparatus determines that a failure occurs in the vehicle transmission, when a value related to a reaction force that acts on the shift barrel during rotation of the shift barrel is deviated from a predetermined range.

Control apparatus for vehicle transmission

A dog clutch includes a rotating member including first dog teeth, an annular dog ring including second dog teeth, and an annular dog sleeve. The rotating member includes first protrusions protruding radially outwardly from the outer circumferences of crests or troughs of the first dog teeth, the dog sleeve includes second protrusions that are configured to come into contact with the first protrusions in a circumferential direction when the dog sleeve moves toward the rotating member in an axial direction, and the first dog teeth and the second dog teeth are disposed at positions at which the first dog teeth and the second dog teeth are able to be engaged with each other in the circumferential direction in a state in which the first protrusions and the second protrusions are in contact with each other.

Dog clutch

A synchromesh device for a transmission includes: a shaft; a sleeve; an idler gear; a gear piece; a synchronizer ring; a first spline, a second spline and a third spline, the first spline of the sleeve being engageable with each of the second spline of the gear piece and the third spline of the synchronizer ring; and a first chamfer, a second chamfer and a third chamfer, formed at one end of the first spline, one end of the second spline and one end of the third spline, respectively, for a spline-engagement and for a thrust-through operation. The first chamfer of the sleeve includes a small-diameter side thrusting through the third chamfer at the time of shifting and a large-diameter side thrusting through the second chamfer at the time of shifting. A chamfer angle of the large-diameter side is smaller than a chamfer angle of the small-diameter side.

Growing community of inventors

Nagoya, Japan

Jun Yabuta