摘要:
A system for controlling a V-belt type CVT is constructed to change a first position of a step motor to a second position of the step motor corresponding to a second target shift ratio if it is determined that the primary-pulley pressure fails to reach a predetermined value. The second target shift ratio is on the high-speed side with respect to a third position of the step motor corresponding to a third target shift ratio to be achieved if it is determined that the primary-pulley pressure reaches the predetermined value.
摘要:
A hydraulic pressure control device is provided that that controls hydraulic pressure of a clutch supplying torque to a continuously variable transmission while the vehicle is stopped and in a running range. The hydraulic pressure control device has an control section that estimates a clutch engagement hydraulic pressure for changing the clutch from an engaged state to a disengaged state based the hydraulic fluid pressure acting on the clutch during the stopping of the rotational movement of a primary pulley of the continuously variable transmission, and then controls regulation of the hydraulic pressure to the clutch from an engaged state to a disengaged state, when the vehicle is stopped and in the running range, so that the torque from the engine does not rotate a secondary pulley of the continuously variable transmission.
摘要:
A forward-reverse changeover mechanism for an automatic transmission is disclosed. The automatic transmission has an input shaft (1) to which a torque is inputted and an output shaft from which a torque is outputted. The forward-reverse changeover mechanism is installed between the input shaft and the output shaft and controls a rotational direction of the output shaft with respect to a rotational direction of the input shaft. The forward-reverse changeover mechanism includes a clutch (5/6) that is engaged when rotation identical or reverse in direction to rotation of the input shaft (1) is transmitted to the output shaft; a piston (9/13) that controls engagement/disengagement of the clutch; and a ring-shaped spring (20) that is interposed between the clutch (5/6) and the piston (9/13) and receives a load from the piston (9/13), wherein the load causes a deformation of the ring-shaped spring (20). A spring constant (k) of the ring-shaped spring (20) switches according to an amount of the deformation of the ring-shaped spring (20).
摘要:
CVT control unit of a belt CVT checks whether a reverse rotation of pulleys is generated. When the reverse rotation is generated, a PLpri torque capacity is calculated from a primary pressure Ppri, and this PLpri torque capacity is used as a torque limit value of a torque-down control of an engine control unit. An input torque to a transmission mechanism is compared with the PLpri torque capacity, and when the input torque exceeds the PLpri torque capacity, shortage of the PLpri torque capacity for the input torque is calculated. Then, this shortage is added to the input torque as a correction amount, and a line pressure is set on the basis of a result of this addition.
摘要:
A clutch engagement control device controls the engagement of a forward clutch (32) and reverse clutch (33) in an automatic transmission connected to an engine (70) in a vehicle. An inhibitor switch (56) outputs a range signal in accordance with a position range of a select lever (51). A manual valve (57) supplies oil pressure selectively to one of the forward clutch (32) and the reverse clutch (33) by changing position in accordance with the position range of the select lever (51). A controller (60) of the clutch engagement control device determines whether an unmatching range condition occurs in which the range of the select lever (51) indicated by the range signal and the range of the manual valve (57) do not match, when the range of the select lever (51) indicated by the range signal is a drive range or reverse range; and suppress an increase in engine rotation speed prior to engagement of the forward clutch or reverse clutch when the unmatching range condition occurs.
摘要:
When a shift lever is shifted from an N range to a D range and a predetermined learning condition is established, a learning timer tm_pulse up to a point at which a pulse signal is detected by a primary pulley rotation speed sensor is calculated, and when a deviation between the learning timer tm_pulse and a reference correction amount ΔP_offset is larger than a predetermined threshold Δt_pulse_dif, a learned correction amount P_offset is updated.