Abstract:
A power transmission system of a vehicle and a gear-shift control method are provided. The power transmission system includes a first drive assembly (101) and a second drive assembly (102). The first drive assembly includes a first automatic transmission (2) and a first motor (1) connected with the first automatic transmission (2) for outputting power to two wheels of the vehicle. The second drive assembly (102) includes a second automatic transmission (2000) and a second motor (1000) connected with the second automatic transmission (2000) for outputting power to the other two wheels of the vehicle. The first and second automatic transmission are configured to be shifted to a preset gear or a gear adjacent to the preset gear, such that when one of the first and second automatic transmission is shifted to the preset gear, the other one of the first and second automatic transmission is shifted to the preset gear or the gear adjacent to the preset gear.
Abstract:
Disclosed is a control device for a vehicle drive device whereby an improvement in vehicle response to accelerator operation by the driver can be achieved, in a vehicle equipped with an internal combustion engine, a supercharger and an automatic transmission. Gear ratio selection control means (80), when the engine (12) is operating in NA condition, if the engine (12) comes to operate in a supercharged condition on change of ratio of the automatic transmission (16) to a first gear ratio (γ1at) in accordance with the gear-change map, performs gear ratio selection control so as to alter the method of selection of the gear ratio (γat) of the automatic transmission (16) in accordance with an increased rate (SPacc) of opening (Acc) of the accelerator. Specifically, in this gear ratio selection control, at the side where the increased rate (SPacc) of opening (Acc) of the accelerator is least, the automatic transmission (16) changes to a first gear ratio (γ1at), but, at the side where the increased rate (SPacc) of degree of opening (Acc) of the accelerator is greatest, the engine (12) is still maintained in the aforementioned NA condition and the automatic transmission (16) is changed to a second gear ratio (γ2at), which is larger than the first gear ratio (γ1at).
Abstract:
A shift control device is mounted on a vehicle and provided with a shift control unit to control a speed ratio of a continuously variable transmission which continuously shifts and allows output of a rotational speed of a driving power source, wherein the shift control unit executes, based on a driving state of the vehicle, a first shift control for suppressing a change of the speed ratio and a second shift control for upshifting the speed ratio to a predetermined speed ratio, and suppresses a change of the speed ratio in the first shift control, followed by shifting the speed ratio to become lower before execution of the second shift control.
Abstract:
A vehicle belt-type continuously variable transmission expands the operating range in which belt slip control is permitted with maintained estimated accuracy of a belt slip condition, to reduce drive energy consumption owing to a reduction in belt friction. It includes a primary pulley (42) and a secondary pulley (43) around which a belt (44) is wound to generate a belt clamping force according to an input torque from an engine (1) by controlling a secondary hydraulic pressure, a belt slip control means ( Fig. 8 ) for controlling the secondary hydraulic pressure according to a phase difference (θ) between oscillation components due to oscillation included in an actual gear ratio and in an actual secondary hydraulic pressure, and an input torque change speed limiting means (step S23 in Fig. 12 ) for determining whether or not to limit vehicle acceleration according to a predetermined acceleration limit permitting condition (steps S21, S22, S26) and limiting the change speed of the input torque to less than a predetermined value when determining to limit the vehicle acceleration.
Abstract:
A vehicle belt-type continuously variable transmission expands the operating range in which belt slip control is permitted with maintained estimated accuracy of a belt slip condition, to reduce drive energy consumption owing to a reduction in belt friction. It includes a primary pulley (42) and a secondary pulley (43) around which a belt (44) is wound to control gear ratio by controlling primary and secondary hydraulic pressures, a belt slip control means ( Fig. 8 ) for controlling secondary hydraulic pressure according to a phase difference (θ) between oscillation components due to oscillation included in an actual gear ratio and in an actual secondary hydraulic pressure, and a transmission speed limiting means (step S23 in Fig. 12 ) for determining whether or not to limit vehicle acceleration according to a predetermined acceleration limit permitting condition (steps S21, S22, S26) and limiting a transmission speed to less than a predetermined value when determining to limit the vehicle acceleration.
Abstract:
A transmission controller (12) permits a 2-1 shift, in which a gear position of a subtransmission mechanism (20) is changed from a second speed to a first speed, when an accelerator pedal has been depressed to or above a predetermined opening. The gear position of the subtransmission mechanism (30) is changed from the second speed to the first speed when an actual through speed ratio passes a mode switch line from a High side to a Low side while the 2-1 shift is permitted in the subtransmission mechanism (30).
Abstract:
This invention is a lock-up clutch control device for an automatic transmission, comprising lock-up clutch control means for controlling a slip amount of the lock-up clutch to a target slip amount. When a variation rate in a required load of an engine reaches or exceeds a predetermined threshold, the target slip amount is increased at a predetermined increase rate, whereupon the target slip amount, having been increased by target slip amount increasing means, is reduced at a predetermined reduction rate. At this time, the predetermined reduction rate is set to decrease as an operating condition when the variation rate of the required load reaches or exceeds the predetermined threshold approaches an operating condition in which an increase rate of a rotation speed on the automatic transmission side of a torque converter relative to an increase in the required load is low.
Abstract:
The transmission is equipped with engaging devices in a gear transmission mechanism, and when up-shifting from a first gear position to a higher second gear position, oil pressure command value for an engaging device used in the up-shift is made up of an open control component, the gradient of which is determined based on input torque, and a feedback control component based on a target gear ratio. In order to prevent a shock during up-shift caused by releasing a foot from the accelerator pedal, the feedback control component is set to zero when the amount of change in the throttle opening is equal to or greater than a predetermined threshold value. As a result of inhibiting increase in feedback in order to make up for a tendency for oil pressure depending on an open control component to decrease as a result of the throttle opening reducing and input torque falling, increase of the oil pressure command value becomes smooth. Peaks of the output torque are therefore suppressed.