摘要:
The invention provides a control apparatus for an automatic transmission for carrying out neutral control and hill-hold control in a range that causes no slip of a hill-hold brake. The control apparatus has a judgment unit for determining, in accordance with a signal output by a gradient detector whether an uphill road is steep enough to cause a hill-hold brake to slip with the hill-hold brake engaged, a hydraulic pressure reducing device for reducing the hydraulic pressure applied to a hydraulic servo of a clutch in order to place the clutch in an all but released state, a hydraulic pressure applying device for applying a hydraulic pressure to a hydraulic servo of a brake in order to engage the brake, and an execution unit for permitting the hydraulic pressure reducing device to reduce the hydraulic pressure applied to the hydraulic servo and the hydraulic pressure applying device to apply a hydraulic pressure to the hydraulic servo only if a stop, or halted, state is detected by a stop-state detector and an uphill road is determined by the judgement unit not to be steep enough to cause the hill-hold brake to slip.
摘要:
A control system for control of a clutch interposed between a fluid transmission unit and a speed change unit in a vehicular automatic transmission. The control system includes a first R.P.M. detector for detecting clutch input side R.P.M. and a second R.P.M. detector for detecting clutch output side R.P.M. A stop state detector determines if the vehicle is at a standstill and a starting operation detector detects a starting operation by the driver. The hydraulic control unit includes a hydraulic servo for applying/releasing the input clutch, a control signal oil pressure generating solenoid valve for generating a control signal oil pressure, a control valve for regulating a forward running range pressure according to the control signal oil pressure to generate a control oil pressure; a change signal oil pressure generating solenoid valve for generating a change signal oil pressure and a change-over valve switchable by the change signal oil pressure, between a first position in which it feeds the forward running range pressure to the hydraulic servo, and a second position in which it feeds the control oil pressure to the hydraulic servo. A failure is decided if the clutch input/output R.P.M. difference is over a set value which is set on the basis of the clutch input/output R.P.M. difference when the starting operation is detected by the starting operation detector. A fail-safe feature causes a shift output to a higher speed gear stage, over-riding a control signal from the pressure booster, when a failure is decided, to output the change signal to the solenoid of the control signal oil pressure solenoid valve to thereby bring the change-over valve into the first position.
摘要:
A shift mechanism for an automatic transmission includes a frictional engagement element arranged between the case of the automatic transmission and one element of a planetary gear unit and a hydraulic servo unit for engaging the frictional engagement element. A one-way clutch is connected to that same one element of the planetary gear unit for selectively locking it to the case. The one-way clutch is axially spaced from the frictional engagement element with the hydraulic servo unit therebetween. Further, the one-way clutch has its outer race connected to the case and its inner race connected to the aforementioned element of the planetary gear unit through a connection member axially extending along the inner circumferential side of the hydraulic servo unit. The inner race is formed with a radial lubricating oil passage in fluid communication with an oil passage in a transmission shaft.
摘要:
A control system for an automatic transmission, having a fluid transmission unit for transmitting the rotation of an engine to a speed change unit. The control system includes a clutch which is applied responsive to selection of forward running range; a one-way clutch which is locked, when the clutch is applied, to establish a forward first speed; a brake for locking the one-way clutch, to block reverse rotation of the output shaft of the speed change unit. First and second hydraulic servos apply, respectively, the clutch and the brake responsive to receipt of oil pressures. A control unit controls the oil pressures fed to the first and second hydraulic servos. The control unit starts the feed of oil pressure to the second hydraulic servo responsive to selection of a forward running range, provided the vehicle is substantially stopped, the engine is idling and the foot brake is engaged. The control unit starts the reduction of the pressure of the first hydraulic servo upon expiration of a set time period and starts transition of the clutch from the applied state to the slipping state of the clutch upon completion of the piston stroke of the second hydraulic servo which applies the brake.
摘要:
An automatic transmission comprising a torque converter and a change-speed transmission having a plurality of planetary gearsets and friction elements. This automatic transmission has a central supporting member fixedly mounted in a transmission case. A drum supported by this central supporting member contains clutch components and a one-way clutch inside. On the outer cylinder of the drum is mounted a band brake. The outer race of the one-way clutch in the drum is connected to the clutch hub in the drum, while the inner race of the one-way clutch is connected to the outer cylinder of the drum.
摘要:
In a hydraulic torque converter having a torus of flatness ratio (L/H) within the range 0.82-0.9, the outer and inner contours of the turbine in a meridional plane through the axis of the turbine each comprises a combination of a plurality of circular arcs, wherein the ratios between the radii of the circular arcs constituting said outer contour is substantially less than 2, and the ratios between the radii of the circular arcs constituting said inner contour is substantially less than 2.As a result, fluid flows through the turbine stably without being biased, increasing the velocity of relative flow along the turbine blade, and raising the normal speed ratio at which the absolute flow is in the direction of no impact, enabling a higher stall torque ratio without reduction in efficiency.
摘要:
A reduction in the weight and size of a speed-change mechanism is obtained by shortening a high-torque transmission system. The speed-change shock is attenuated by reducing an inertia torque in a muilti-stage vehicular automatic transmission. The vehicular automatic transmission is equipped with a planetary gear set that receives a decelerated rotation and a non-decelerated rotation as inputs and outputs a plurality of speed-change rotations, a reduction planetary gear, an input shaft that passes through an inner side of the planetary gear set, first and third clutches that couple the input shaft to two different speed-change elements of the planetary gear set respectively through the reduction planetary gear in an engageable and disengageable manner, and a second clutch that couples the input shaft to the other speed-change element of the planetary gear set in an engageable and disengageable manner. The reduction planetary gear and the third clutch for transmitting a high torque are arranged on one side of the planetary gear set, whereas the first clutch for transmitting a high torque is arranged on the other side of the planetary gear set.
摘要:
A control system for an automatic transmission includes a fluid transmission unit connected to an engine; a clutch; a hydraulic servo; output RPM detector for detecting the output RPM of the fluid transmission unit; oil pressure generator for generating the oil pressure fed to the hydraulic servo; and a control unit. The control unit includes a booster for raising the oil pressure according to preset characteristics; change rate detector for detecting the RPM change rate of the output RPM in a preset range at the application of the clutch; and a corrector for correcting the preset characteristics by comparing the detected RPM change rate and a reference RPM change rate. The change rate detector detects the RPM change rate only when the output RPM at the time of starting the engagement of the clutch is higher by a preset value than the maximum of the output RPM in the preset range.
摘要:
An automatic transmission comprises a reduction planetary gear, two clutches transmitting a decelerated rotation transmitted from the reduction planetary gear, and a planetary gear set comprising two elements to which the decelerated rotation is inputted through the two clutches. The reduction planetary gear and the two clutches are arranged in one side of the planetary gear set. The second clutch is closer to the planetary gear set than the clutch. The input side member of the first clutch is connected to an output element of the reduction planetary gear and the input side member of the second clutch. The output side member of the first clutch is extended through the radial inner space of the second clutch and connected to one of the two elements of the planetary gear set. Thus, no member is arranged in the radial outer side of the both clutches, and the both clutches are radially enlarged.
摘要:
An automatic transmission, which establishes automatic shifts in a multiple gear stages by selectively inputting a plurality of input rotations to a planetary gear set, includes first and third clutches connected through a reduction planetary gear to an input shaft and transmits a decelerated rotation to the planetary gear set and a second clutch directly connected to the input shaft and transmits a non-decelerated rotation to the planetary gear set. The reduction planetary gear is arranged on the end of a boss portion of a transmission case wall and the one element is fixed to the end of the boss portion, hydraulic servos of the first and third clutches are arranged on the boss portion, a hydraulic servo of a second clutch is arranged in the other side of the reduction planetary gear from the hydraulic servos, and the hydraulic paths for the hydraulic servos are formed in the boss portion.