Toyota Jidosha Kabushiki Kaisha

Toshiyuki Asada

Yasuo Hojo

Hideo Tomomatsu

Yasunori Nakawaki

Naoki Moriguchi

Yasuhiko Higashiyama

Toshitake Suzuki

Akiharu Abe

Fumihiro Ushijima

Seitoku Kubo

Shinya Nakamura

Akio Numazawa

Masafumi Kinoshita

Yasuhiko Higushiyama

Takaaki Kuroda

Whether the load on the automobile is normal or heavy or whether the automobile is in a normal, oversteering or understeering condition is detected by a rising-up performance of the yaw rate in the initial transient state of steering from a comparison of an actual yaw rate detected by a sensor and a standard yaw rate calculated from vehicle speed and steering angle, and the speed stage shifting of the automatic transmission is modified according to the result of the comparison so as to compensate for a change of load or a deviation of steering performance from a normal condition.

Speed stage shifting of automatic transmission of automobile in relation

A control system of an automatic transmission for determining and setting a gear stage on the basis of at least two of the parameters including a vehicle speed and a throttle opening. The control system comprises: a first detector for detecting a first parameter; a second detector for detecting a second parameter; a gear stage memory for determining and storing speed stage areas for holding the gear stages individually in terms of the first and second parameter and any two speed stage areas in a partially overlaid manner; a shift decider for determining a shift to be executed, on the basis of the first parameter outputted from the first detector, the second parameter outputted from the second detector, and the stored content of the gear stage memory; and a gear stage determiner for determining a gear stage to be set, if there are a plurality of gear stages determined by the first parameter and second parameter detected, at any of the gear stages.

System for and method of controlling automatic transmission

An automatic transmission which includes a device for selecting and temporarily setting such one of other speed stages, if any, between a present speed stage and a target speed stage as can have a small number of fluctuating revolutions of rotary members of planetary gear sets of the automatic transmission and two or less frictional engagement elements to be switched.

Automatic transmission

A speed changing gear device for an automatic transmission, comprising a main gear assembly for providing a plurality of operating positions, and an auxiliary gear assembly for providing a direct drive position and a speed changing drive position. The main gear assembly includes a single-pinion type first planetary gear unit having a first sun gear, a first planetary gear, a first ring gear and a first carrier, and a single-pinion type second planetary gear unit having a second sun gear, a second planetary gear, a second ring gear and a second carrier. The auxiliary gear assembly includes a third planetary gear unit having a third sun gear, at least one third planetary gear, a third ring gear and a third carrier. The first carrier and second ring gear are fixed to each other, or selectively connected to each other by a first clutch. The first and second sun gears, and the first sun gear and second carrier are selectively connected to each other by a second and a third clutch, respectively. The first sun gear, second sun gear and second carrier are selectively inhibited from rotating by a first brake, and the second carrier is inhibited from rotating by a second brake.

Speed changing gear device having two independent gear assemblies

A shift control system and method for use in an automatic transmission includes a plurality of frictional engagement elements and a gear train settable to a plurality of speed stages of different gear ratios according to the engagement/release states of the frictional engagement means and having a plurality of different engagement/release combinations for the frictional engagement elements to set a predetermined one of the speed stages. A shift decision unit decides a shift to be performed. A speed stage selection determines a speed stage to be set after the shift. An engagement/release pattern selects and outputs one of the engagement/release combinations of the frictional engagement elements for setting a speed in which either the current speed stage or the speed stage to be set after the shift is the predetermined speed stage, wherein two or less of the frictional engagement elements have their engagement/release states switched during the shift.

Shift control system and method for automatic transmissions

A shift control system for controlling the shifting of a vehicular automatic transmission including a plurality of frictional engagement members and having a plurality of engage/release combinations of the frictional engagement members for setting a predetermined one of gear stages. The shift control system comprises: a changer for effecting a change-over between an automatic shift mode for shifting the automatic transmission automatically on the basis of the running condition of the vehicle and a manual shift mode for shifting the same manually on the basis of the manipulation of the driver; and an engage/release pattern selector for selecting, in the manual shift mode, an engage/release combination of the frictional engagement members, which is different from the combination selected in the automatic shift mode, as that for setting the predetermined gear stage.

Shift control system for automatic transmissions

A shift control system for use in an automatic transmission which includes a plurality of frictional engagement components, and a gear train adapted to set a plurality of speed stage having (Tables 1 and 3) different gear ratios in accordance with the combination for engagement/release of the frictional engagement components and enabled to select a combination for engaging and releasing any of the frictional engagement components as that for engagement/release of the frictional engagement components for setting any of the speed stages. The shift control system includes a decider for deciding a shift to be executed; an engagement/release pattern selector for selecting a combination for engaging the frictional engagement components in a first combination (Table 3) for setting a predetermined one of the speed stages, before the shift is decided, and a second combination (Table 3) for the predetermined one of gear stages if the shift is decided; and an output device for outputting both an instruction signal for executing the shift and an instruction signal for setting the second combination (Table 1) of the frictional engagement components.

Shift control system and method for selecting engagement/disengagement

A shift control system for use in an automatic transmission having a gear train to be set to a plurality of gear stages of different gear ratios in accordance with the engagement/release states of a plurality of fricitional engagement devices. The gear train is enabled to set a predetermined gear stage in accordance with plural kinds of combination of the engagement/release of the frictional engagement devices. The shift control system comprises: an input torque detector for detecting input torque to be inputted to the gear train; a torque evaluator for evaluating the level of the input torque; and an engagement/release pattern selector for selecting the combination of engagement/release of the frictional engagement devices for setting the predetermined gear stage, on the basis of the result of the input torque evaluated by the torque evaluator.

Shift control system and method for automatic transmission of vehicles

A shift control system for use in an automatic transmission which comprises: a plurality of frictional engagement components; and a gear train adapted to set a plurality of speed stages having different gear ratios in accordance with the combination for engagement/release of the frictional engagement components and enabled to select a combination for engaging and releasing any of the frictional engagement components as that for engagement/release of the frictional engagement components for setting any of the speed stages. The shift control system comprises: a detector for detecting the engagement failure of the frictional engagement components; an engagement/release pattern selector for selecting a combination for releasing any one of the frictional engagement components as the combinations for engagement/release of the frictional engagement components for setting any one of the speed stages, if the engagement failure of any one of the frictional engagement components is detected; and an output device for outputting an instruction signal for setting the selected combination for engagement/release of the frictional engagement components.

Shift control system and method for automatic transmission

A shift control system for a vehicular automatic transmission including a gear train to be set to a plurality of gear stages in accordance with the engaged or released states of a plurality of friction devices. The shift control system comprises: a mode selector for interchanging an automatic shift mode to effect a shift according to a first gear stage train, which is composed of a plurality of gear stages selected from those capable of being set with the gear train, a manual shift mode to effect a shift according to a second gear stage train, which is composed of other plural gear stages selected from those capable of being set with the gear train; an automatic shift output device for outputting a shift signal in accordance with the running state of the vehicle to set any of the gear stages of the first gear stage train when the automatic shift mode is selected; a gear stage selector for outputting an upshift signal and a downshift signal in response to the manual operations of upshift and downshift, respectively, when the manual shift mode is selected; a manual shift output device responding to the upshift signal and downshift signal outputted from the gear stage selector, for outputting a shift signal to select a gear stage from the second gear shift train and to set the selected gear stage; and a hydraulic controller for feeding/releasing an oil pressure to the friction devices to set the gear stage which is commanded by the shift signals outputted from the automatic shift output device and the manual shift output device.

Shift control system with an automatic first sequence and a manual

A shift control system for an automatic transmission which can be set both at main gear stages selected on the basis of the running state of a vehicle and at intermediate gear stages having gear ratios intermediate between those of the main gear stages. The shift control system comprises: a running state detector for detecting the running state; a shift decider for deciding a main gear stage to be set, on the basis of the running state detected; a condition decider for deciding whether or not a shift between the main gear stages decided by the shift decider satisfies a predetermined condition; and an intermediate stage setter for deciding an intermediate stage to be set in place of the main gear stage, which was decided by the shift decider, on the basis of the result decided by the condition decider.

A speed changing gear device for an automatic transmission, comprising a main gear assembly for providing a plurality of operating positions, and an axiliary gear assembly for providing a direct drive position and a speed changing drive position. The main gear assembly includes a single-pinion type first planetary gear unit having a first sun gear, a first planetary gear, a first ring gear and a first carrier, and a single-pinion type second planetary gear unit having a second sun gear, a second planetary gear, a second ring gear and a second carrier. The auxiliary gear assembly includes a third planetary gear unit having a third sun gear, at least one third planetary gear, a third ring gear and a third carrier. The first carrier and second ring gear are fixed to each other, or selectively connected to each other by a first clutch. The first and second sun gears, and the first sun gear and second carrier are selectively connected to each other by a second and a third clutch, respectively. The first sun gear, second sun gear and second carrier are selectively inhibited from rotating by a first brake, and the second carrier is inhibited from rotating by a second brake.

An automatic transmission wherein a gear train is constituted by three single pinion type planetary gear sets, provided with a first planetary gear set having a first sun gear, a first ring gear, and a first carrier holding pinion gears meshing with the first sun gear and the first ring gear, a second planetary gear set having a second sun gear, a second ring gear which is normally or selectively connected with the first carrier, and a second carrier holding pinion gears meshing with the second sun gear and the second ring gear, a third planetary gear set having a third sun gear normally or selectively connected to the second carrier, a third ring gear which is continuously connected with the first carrier, and a third carrier holding pinion gears meshing with the third sun gear and the third ring gear and connected to the output shaft, a first clutch means which selectively connects the input shaft and the first ring gear, a second clutch means which selectively connects the first sun gear and the second carrier, a third clutch means which selectively connects the input shaft and the first sun gear, a fourth clutch means which selectively connects the first sun gear and the second sun gear, a first brake means which selectively stops the rotation of at least the third sun gear among the second carrier and the third sun gear, a second brake means which selectively stops the rotation of the first sun gear, and a third brake means which selectively stops the rotation of the second sun gear, at least five forward speeds and one reverse speed being settable as transmission stages.

An automatic transmission includes a plurality of frictional engagement means and a gear train including a plurality of rotary members and adapted to be set to a plurality of speeds of different gear ratios in accordance with the engagement/disengagement statuses of the frictional engagement means. The gear train has a plurality of kinds of combination patterns of engagement/disengagement of the frictional engagement means for setting a predetermined speed and the number of revolutions of any of its rotary members can vary according to which of the engagement/disengagement patterns is selected. Speed control means is provided for selecting one of the combination patterns of the frictional engagement means for setting the predetermined speed so as to decrease the fluctuating number of revolutions of the rotary members.

Automatic transmission and speed change control method

A planetary gear device having a first and a second single-pinion planetary gear unit and a third double-pinion planetary gear unit, which are coaxially disposed so as to provide different speed reduction ratios. The three gear units have respective first, second and third sun gears, respective first, second and third ring gears, and respective first, second and third carriers rotatably supporting planetary pinions. The first and second sun gears are fixed together or selectively connectable to each other, and the first carrier, second ring gear and third carrier are fixed together or selectively connectable to each other. Further, the second carrier and the third sun gear are fixed together or selectively connectable to each other. The present arrangement allows shifting operations of the gear device, without concurrent disengagement and engagement of different clutches.

Growing community of inventors

Susono, Japan

Toshiyuki Asada