Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Yasushi Inagawa

Yoshiharu Saito

Takanori Kon

Masamitsu Fukuchi

Shinya Majikina

Yoshikazu Nemoto

Shirou Godai

Yuji Yasui

Kazutomo Sawamura

Hideo Koyama

Noriyuki Yagi

Takahiro Matsuda

Shintaro Kameda

Masahide Saito

Yoshiari Takagi

Masakazu Shiraishi

Atsuhiro Saeki

Hitoshi Kondou

Mitsumasa Furumoto

Hirotake Omoto

Hidekazu Araki

Christoph Karger

Hiroyuki Okuda

Satoshi Kato

A control apparatus of an automatic transmission including a plurality of gear mechanisms, frictional elements, an oil pressure supply device which supplies an oil pressure for operating the frictional elements between an engaged state and a disengaged state and an oil pressure controller which controls an oil pressure for operating the plurality of frictional elements. The oil pressure controller determines a heat quantity absorbed by the plurality of frictional elements when the frictional elements are switched between the engaged state and the disengaged state, and changes an operation state before the frictional elements proceed to the engaged state or the disengaged state, in accordance with whether the frictional elements have absorbed a predetermined heat quantity.

Control apparatus and method of automatic transmission

Adding a driver's intention and running environments to conditions for cancelling a delay of an upshift after kickdown enables the upshift at a suitable timing depending on a vehicle's running environments and aspects of the driver's operation. A shift control device for automatic transmission calculates an allowance driving force of the vehicle when upshifting at a current vehicle speed and throttle opening, and also calculates a threshold value of a driving force depending on an average value of throttle opening variation, an average value of vehicle speed variation, a cornering judgment of a winding degree of a road on which the vehicle is running and a gradient judgment of a gradient of a road surface on which the vehicle is running. Then, after comparing the threshold value and the allowance driving force, the device permits an upshift when the allowance driving force is larger than the threshold value.

Shift control device for automatic transmission

In a control apparatus for an automatic transmission, it is configured to calculate a change amount (&#x394;NC estimation value) of an output rotational speed of the transmission (S); calculate an average (I phase initial average G) of the change amount of the output rotational speed over a predetermined period of an initial inertia (I) phase of shifting; calculate an average (after-shift average G) of a vehicle acceleration after the completion of the shifting, assuming that the change amount of the output rotational speed indicates the vehicle acceleration G; calculate a difference (I phase initial G) between the average of the change amount of the output rotational speed and the average of the vehicle acceleration; incrementally and decrementally correct the desired value of the transmission torque of the frictional engaging element such that the calculated difference falls within a predetermined range; and control supply of hydraulic pressure to the frictional engaging element such that it becomes the corrected desired value (Sto S). With this, since the vehicle acceleration at shifting is estimated and evaluated and based thereon, variation in the transmission torque of the frictional engaging element, etc., is learned, it becomes possible to fully exploit the potential of the frictional engaging element, thereby improving a feel given to the vehicle occupant(s) at shifting.

Control apparatus for automatic transmission

In a control apparatus for an automatic transmission having multiple speeds constituted by four sets and speed selecting mechanisms corresponding to the four sets, assuming the speeds as seven among eight speeds of A to H in order of gear ratio, the four sets are constituted by a first set of A having a largest gear ratio and C that is next but one; a second set including at least H having a smallest gear ratio; a third set of B and D between two of the first set; and a fourth set including two of E, F and G between the second and third sets, and one of first and second pressure regulators selectively supplies hydraulic pressure to two of the mechanisms corresponding to the first and second sets, while the other thereof selectively supplies hydraulic pressure to two of the mechanisms corresponding to the third and fourth sets.

A hydraulic fluid change indicating device for an automatic transmission includes a first deterioration rate calculating unit; a deterioration acceleration coefficient calculating unit; and a thermal hydraulic fluid deterioration calculating unit for calculating a thermal hydraulic fluid deterioration according to the first deterioration rate and the deterioration acceleration coefficient. The device further includes a second deterioration rate calculating unit according to an engine speed, input shaft speed, and output shaft speed; a mechanical hydraulic fluid deterioration calculating unit for calculating a mechanical fluid deterioration according to the second deterioration rate; and a determining unit for determining whether or not the thermal hydraulic fluid deterioration or the mechanical hydraulic fluid deterioration is greater than a predetermined hydraulic fluid change threshold.

Hydraulic fluid change indicating device for automatic transmission

A shift control apparatus comprises clutches driven by shift solenoids and whether or not the raising of the rotation speed occurs in an internal combustion engine is determined. If the raising of the engine rotation speed is detected, a hydraulic pressure learn correction is made to engagement hydraulic pressure and a time learn correction is made to the hydraulic pressure supply preparation time. The correction ratio of the energization-hydraulic pressure characteristic (I-P characteristic) of clutch clearance and the shift solenoid is set so as to become an appropriate distribution ratio and the learning is started based thereon.

Shift control apparatus of automatic transmission for vehicle

A system for controlling an automatic transmission of a vehicle, wherein the initial value of the desired pressure to be supplied to a hydraulic clutch for the current gear now being engaged is determined appropriately, when conducting a power-on downshifting, so as to decrease the shift shock experienced by the vehicle occupant effectively, irrespectively of the change in the throttle opening, while ensuring to reduce the volume of the mapped data.

Control system for automatic vehicle transmissions

A system for controlling an automatic transmission of a vehicle, wherein if the change of the destined gear GB (i.e., the target gear SH) is required when the jumping shift, i.e., two-gear downshifting is in progress, the input/output rotational speed ratio GRATIO (indicative of degree of shift progress) is compared with the predetermined input/output rotational speed ratio &num;GRCN312 or &num;GRCN423, and based on the result of comparison, how the shift to establish or effect the required destined gear GB, i.e., the shift mode QATNUM is determined, thereby enabling to improve or enhance the response to the change of the destined gear GB during two-gear downshifting. It can also prevent the clutch from being degraded in such a shifting.

A system for controlling an automatic transmission of a vehicle, in which a pressure supply time to complete removal of the clutch-stroke play is determined based on the input shaft rotational speed. And a residual oil amount in the clutch is estimated and the time is corrected by the residual oil amount. The preparatory pressure to be supplied within the time is also determined based on the input shaft rotational speed and the ATF temperature. With this, it becomes possible to effect the clutch-stroke play removal within a less variant time and with a good response, thereby decreasing the shift shock effectively so as to improve the feeling of the vehicle occupant.

A system for controlling an automatic transmission of a vehicle, wherein a pressure to be supplied to the hydraulic clutch of a target gear is determined based on a desired value of acceleration of gravity acting in the longitudinal direction of the vehicle and other parameters including an engine torque, thereby decreasing the shift shock effectively, while ensuring to finish the shift within an expected period of time. Moreover, the engine torque is estimated using a parameter indicative of inertia torque used for raising the engine speed. With this, it becomes possible to determine the engine torque inputted to the transmission, thereby decreasing the shift shock more effectively.

A system for controlling an automatic transmission of a vehicle, wherein the hydraulic pressure to be supplied to the frictional engaging element such as a hydraulic clutch is determined, taking the performance of tracking or follow-up of the hydraulic pressure into account so as to enhance the control toughness against the engine speed change, thereby decreasing the shift shock effectively so as to improve the feeling of the vehicle occupant, while ensuring to prevent the engine from revving over or excessively. Further, the friction coefficient of the hydraulic clutch is calculated additionally taking parameters including the rotational difference thereof into account to determine the pressure to be supplied to the frictional engaging element, thereby further decreasing the shift shock effectively.

A down-shift control system is provided, by which if sufficient torque cannot be obtained for an acceleration request or intention at a shift position, a down-shift operation is suitably performed so as to realize a reliable driving capability and no shift-busy phenomenon occurs. The system includes a section for calculating target driving force of a vehicle according to a degree of opening of an accelerator pedal and a speed of the vehicle; a section for detecting the present shift position of the vehicle; a section for calculating target engine torque based on the target driving force and the present shift position; a section for comparing the target engine torque with a set value determined according to torque characteristics of the engine; a section for performing an accumulating operation relating to the degree of opening if it is judged that the target engine torque equals or exceeds the set value; and a section for outputting a down-shift command if the accumulated value exceeds a threshold relating to the degree of opening.

Down-shift control system based on driver's intention for acceleration

A throttle controller is provided so as to reduce a load imposed on the drive and transmission system in the stall state in which both the accelerator and brake are depressed. The controller comprises a throttle control section for calculating a degree of opening of the throttle for generating a driving force in accordance with the actual degree of depression of the accelerator used as a target degree of opening of the throttle so as to drive the vehicle by a target driving force calculated based on the actual degree of depression of the accelerator; a section for determining the stall state in which the gear lever is in a driving gear; the actual degree of depression of the accelerator is larger than a predetermined degree; the brake is operated; and the speed is smaller than a predetermined speed; and a storage section for storing a predetermined degree of opening of the throttle which is read out when the actual degree of depression of the accelerator is larger than the predetermined degree, and wherein the throttle control section limits the target degree of opening of the throttle to the predetermined degree stored in the storage section when the stall state of the vehicle is determined.

Throttle controller for limiting degree of opening of throttle in stall

The lock-up clutch control apparatus is provided with reference values for operating variations of the accelerator pedal predetermined for respective gear positions. The lock-up clutch control apparatus comprises a tightening permission judgement device 25 for judging whether it is appropriate to permit or prohibit tightening of the lock-up clutch, based on comparison between a reference value and an operating variation at present car conditions. Thereby, the lock-up clutch control apparatus is capable of reflecting the driver's intention to accelerate or reduce the car speed and is capable of enhancing drivability as well.

Lock-up clutch control apparatus

A lock-up control device controls an engaging force of a lock-up clutch, which shares engine output with a torque converter to transmit it toward an input shaft of a transmission of a car. First, target driving force is produced based on accelerator pedal opening and car velocity. Then, required torque is produced based on a gear ratio and the target driving force. Target engine speed is produced based on the required torque, wherein the target engine speed is set to avoid occurrence of abnormal sounds and abnormal vibrations. Thus, the lock-up clutch is controlled in such a way that real engine speed does not become less than the target engine speed in case of a gear change corresponding to a shift-up operation, for example. Basically, the lock-up clutch is controlled to have engaging force, which is made as maximal as possible to improve fuel efficiency. In other words, the lock-up clutch is controlled to be as tightly as possible. Or, the lock-up clutch which is initially set at a tight state is turned off just after the gear change start timing if it is predicted that the real engine speed after the gear change will become lower than the target engine speed.

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Wako, Japan

Yasushi Inagawa