Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Osahide Miyamoto

Tatsuyuki Ohashi

Shoichi Tanizawa

Norio Nakauchi

Kazuo Okada

Kouji Shibuya

Yoshiharu Saito

Toshiyuki Suzuki

Kazuhiko Kitano

Shinichi Nishio

Hiroyuki Takeo

Masatoshi Shimizu

Hideo Fukushi

Tomohisa Kaneda

Takamichi Shimada

Yutaka Ishikawa

Eijiro Shimabukuro

Akio Muto

Toru Yamashita

Satoru Sunada

Koichi Fushimi

Fumio Egashira

Hideki Machino

Ryuichi Mori

Masaaki Takamatsu

Masahide Saito

Masanori Takagi

Takehiro Katakura

Kaname Tokita

Akio Tsuura

Hiromitsu Ishibashi

Hiroyuki Katano

Tadahiro Suzuki

Yoshirou Tashiro

Yasuhiro Gokan

Yoshiaki Shuto

Hironori Fujita

A vehicle transmission control apparatus includes an expected-acceleration calculator configured to calculate an expected acceleration of a vehicle based on at least an engine load and a vehicle speed. An actual-acceleration calculator is configured to calculate an actual acceleration of the vehicle. An uphill determination device is configured to calculate an uphill determination value based on a difference between the expected acceleration and the actual acceleration and configured to calculate a corrected uphill determination value by subjecting the uphill determination value to moderating calculation using a moderating coefficient and to update the corrected uphill determination value in accordance with the moderating coefficient. A transmission-characteristic selecting device is configured to select one of transmission characteristics based on the corrected uphill determination value. A transmission controller is configured to perform transmission control based on the transmission characteristic selected by the transmission-characteristic selecting device.

Vehicle transmission control apparatus

A controller for automatic transmission that performs feedback control on a slip ratio of a lockup clutch is adapted to select one target slip ratio from a plurality of target slip ratios based on a detected automatic transmission fluid temperature of a torque converter. Thus, the controller can ensure good followability to a target value of the feedback control even when the automatic transmission fluid temperature is low. The controller can effectively prevent engine hunting and the associated vibrations of vehicle body. Therefore, the controller can accomplish a favorable slip control of the lockup clutch even if an operating range of the lockup clutch is expanded to a range where the automatic transmission fluid temperature is low.

Controller for automatic transmission

A hydraulic pressurizer system () comprises a drive source (an engineand a motor generator), which drives a hybrid vehicle (), a mechanical oil pump (), which is driven by the drive source, an electrical motor (), which is activated by a 12V battery (), an electrical oil pump (), which is driven by the electrical motor (), and a control unit (), which activates the electrical motor (). The pressurizer further comprises a ratio-change mechanism (), which is activated by hydraulic oil supplied by the mechanical oil pump () and by the electrical oil pump () to establish a speed change ratio, at which the rotational driving force of the drive source is transmitted to wheels () with a rotational speed change. For executing a control for stopping the drive source, the control unit () executes a cleaning operation, which operates the electrical oil pump () for a predetermined time before the stopping of the drive source.

Hydraulic pressurizer system

A hydraulic pressurizer system comprises a drive source, which drives a hybrid vehicle, a mechanical oil pump, which is driven by the drive source, an electrical motor, which is activated by a 12V battery, an electrical oil pump, which is driven by the electrical motor, and a control unit, which activates the electrical motor. The pressurizer further comprises a ratio-change mechanism, which is activated by hydraulic oil supplied by the mechanical oil pump and by the electrical oil pump to establish a speed change ratio, at which the rotational driving force of the drive source is transmitted to wheels with a rotational speed change. The control unit memorizes a characteristic value, which is specified from the temperature of the hydraulic oil and from the rotational speed of the electrical motor, and a threshold value for the rotational speed of the electrical motor, which threshold value corresponds to the characteristic value.

A control system for an automatic transmission of a vehicle is disclosed. The automatic transmission operates in a manual operating mode in which a shift position of the automatic transmission can be changed according to a shift instruction issued by a driver of the vehicle, or in an automatic operating mode in which the shift position is automatically selected. In the control system, a slow running intention of the driver is detected. A first shift position is set to a starting shift position at the time of starting the vehicle when the slow running intention of the driver is not detected in the manual operating mode. A second shift position which is lower in transmission gear ratio than the first shift position is set to the starting shift position when the slow running intention of the driver is detected in the manual operating mode.

Control system for an automatic transmission of a vehicle

A control system for a hydraulically-operated transmission for a vehicle is disclosed. The transmission is connected to a crankshaft of an internal combustion engine and having a plurality of friction engagement elements. A working oil temperature of the transmission, a cooling water temperature of the engine, and an operating condition of the transmission are detected. An estimated value of the working oil temperature is calculated on the basis of the detected cooling water temperature and the detected operating condition of the transmission. A weighting factor is calculated according to the detected working oil temperature. A weighted average value of the working oil temperature and the estimated working oil temperature is calculated as an actual working oil temperature by using the weighting factor. A hydraulic pressure of the working oil is controlled according to the actual working oil temperature.

Control system for a hydraulically-operated transmission of a vehicle

At downshifting, hydraulic pressure of hydraulic clutch on engaging side (ON clutch pressure) is increased when an input and output speed ratio ('Gratio') has fallen below a predetermined value YGDNS. YGDNS is variably set depending on the vehicle speed and the engine temperature so that it becomes a lower value at a high vehicle speed than at a low vehicle speed, and a higher value at a low engine temperature than at a high temperature. When a downshifting command to a still lower speed stage is issued during downshifting control (when FTBD=1), a downshifting completion processing is performed in the course of the downshifting control (step in S111). Oil pressure in a hydraulic engaging element on the disengaging side QDNOFF and oil pressure in a hydraulic engaging element on the engaging side QDNON are switched to the oil pressures at the time of completion of downshifting, to thereby complete the first step downshifting control at an early time. In order to prevent unnecessary speed changing at the time of tire locking, downshifting is prohibited when deceleration of the vehicle speed has exceeded a predetermined value (when a setting of FLOCK=1 is made).

Control apparatus for hydraulically operated vehicular transmission

Measurement is made of a time of lapse from the time at which the hydraulic pressure of the hydraulic engaging element on engaging side to be engaged at the time of speed changing has increased to a predetermined pressure. Even if an input and output speed ratio of the transmission does not fall within a predetermined range, i.e., a range between YG(N+1)L and YG(N+1)H, which serves as a basis for judging whether the speed changing has been completed or not, a processing of speed change completion is performed when the above-described value TMSTB-TM has reached a predetermined value YTMUP4, to boost the ON pressure to the line pressure.

In a control apparatus for a hydraulically operated vehicular transmission having a plurality of speed stages to be established by a selecting operation of a plurality of hydraulic clutches, when a command to downshift to G(N-2) is issued in the course of downshifting to G(N-1) and a flag FTBD is set to 1, a control is performed to accelerate the time of completion of the downshifting control to G(N-1). When that oil temperature in the transmission which is detected by an oil temperature sensor is lower than a predetermined value, the setting of FTBD to 1 is prohibited. Therefore, at the time of low oil temperature, the downshifting to G(N-1) is performed in an ordinary manner. At the time of starting of the downshifting control from G(N-1) to G(N-2), the hydraulic pressure in the hydraulic clutch for the speed stage G(N-1) is sufficiently increased. A smooth downshifting to G(N-2) can thus be smoothly performed without the occurrence of excessive engine racing.

Even if a rotational speed of an engine has already increased due to slipping of a fluid torque converter at the time of start of downshifting, a smooth downshifting is performed. For that purpose, there is obtained a speed change developing degree function K(etrm) of the rotational speed of the engine at the time of start of downshifting, the developing degree being dependent on an increase in the rotational speed of the engine due to slipping in the fluid torque converter. The function K(etrm) is obtained with a speed ratio 'etrm' of the fluid torque converter at the time of starting of downshifting as a parameter. A boosting correction value QDNOFFZ is computed by multiplying a reference correction value QDNOFFZO by K(etrm) (step S108-5). The hydraulic pressure of the hydraulic engaging element on the disengaging side during downshifting is boosted by the amount of QDNOFFZ (step S108-6).

The disadvantage in the conventional transmission in which a high speed stage is established during the initialization operation by the starting up of an electronic control circuit, is eliminated. The disadvantage is that the rotational speed of an engine lowers due to the establishment of the high speed stage during the initialization operation at the time of running in a low speed stage, with the result that the recovery of the driving force after the completion of the initialization operation is delayed. To solve this disadvantage, valves that can switch the transmission to a neutral condition in the running range are provided. During the initialization operation of the electronic control circuit (20), a neutral signal which shifts the transmission (1) to the neutral condition is output (S902) to the valves. If the transmission (1) is in a running range, there is performed an in-gear control, after the completion of the initialization operation, to establish a speed stage depending on the vehicle speed at that time (S908).

There are prevented shocks that will occur when a switchover speed changing is made to transfer from one speed changing, in the midst of that speed changing, to another speed changing when the input and output speed ratio 'Gratio', which serves a control parameter, is not accurately detected. For that purpose, there is used a flag FGFAIL for setting '1' when the input and output speed ratio 'Gratio', at the time of non-speed changing, does not lie within a predetermined range based on the gear ratio of the speed stage that is being established at that time. A switchover speed changing in which switching to another speed changing is made during a speed changing is prohibited when FGFAIL=1.

In a control apparatus for a hydraulically operated vehicular transmission, the hydraulic pressure of a hydraulic clutch on the engaging side which is engaged at the time of speed changing (engaging pressure) is detected by a hydraulic pressure sensor. When the detected value of the engaging pressure has exceeded a predetermined value, the hydraulic pressure of a hydraulic clutch on the disengaging side to be disengaged at the time of speed changing (disengaging pressure) is reduced to a predetermined low pressure. Even if the detected value of the engaging pressure has exceeded a predetermined value YPC, the decrease in the disengaging pressure down to a predetermined low pressure QUPOFFB is delayed by a predetermined time YTMUP9 at the time of low oil temperature when the detected value of an oil temperature to be detected by an oil temperature sensor is below a predetermined value YTO. When a discrimination is made as to whether the detected value of the engaging pressure PC(N+1) has exceeded the predetermined value YPC from a predetermined time after the start of the speed changing, the time to start the discrimination may be delayed by a predetermined time at the time of low oil temperature.

Transmission controller responsive to low oil temperature to delay the

When switching to a forward running is made while a vehicle is running in a reverse direction, a switching to the forward running condition is made at an early time to thereby prevent the deterioration of the durability of the hydraulic engaging element due to slipping. For that purpose, when a vehicle speed (V) has exceeded a predetermined value (YVa) in a reverse range (R) and also when the vehicle speed (V) has never fallen below the predetermined value (YVa) in a neutral range (N), a reverse signal (FREV=1) is outputted. If FREV=1 at the time of switching to the forward range, the relationship between the vehicle speed and the speed stage (speed change map) is set to one (a reverse-running-measure speed change map) which is different from that at an ordinary time, to thereby determine the speed stage to be established. Then, a low speed stage is established even at a relatively high vehicle speed. Switching is thus made at an early time to the forward running condition with a large torque to be transmitted via the low speed stage.

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Wako, Japan

Osahide Miyamoto