摘要:
A method of controlling noise/vibration in a vehicle having a powertrain includes sensing noise/vibration in the vehicle. An operating point of the powertrain is adjusted and a constant transmission output power is maintained to reduce the noise/vibration.
摘要:
During a downshift of a belt-drive continuously variable transmission, occurring owing to vehicle deceleration, a CVT controller foretells that a slippage between a drive belt and each of primary and secondary variable-width pulleys tends to occur, when a primary pulley pressure is less than a first predetermined pressure level and a primary pulley speed is less than a first predetermined rotational speed. When the belt slippage has been foretold, the CVT controller inhibits the primary pulley pressure from dropping by setting an actual transmission ratio calculated before a set time period from a time when the slippage has been foretold or a transmission ratio of a relatively higher speed side as compared with a ratio-change operating state obtained when the slippage has been foretold, to a desired transmission ratio, or by relatively rising a line pressure as compared with a line pressure level produced when the slippage has been foretold.
摘要:
A shift hydraulic apparatus and method are provided for a vehicular automatic transmission constituted by a torque converter and a continuously variable transmission. A bypass circuit enables an upstream side hydraulic circuit of the hydraulic circuit to communicate with a downstream side hydraulic circuit. A switching valve enables a switching between a communication state of the bypass circuit and a non-communication state thereof. Through the switching valve, both communication state and the non-communication state of the bypass circuit are controlled.
摘要:
In shift control apparatus and method for a belt-type continuously variable transmission, a shift ratio between the primary pulley and the secondary pulley is controlled, a shift speed is detected, the shift speed being a variation quantity of the shift ratio per unit of time; and an advance of the shift ratio control is suppressed to suppress the shift speed when a magnitude of the shift speed is equal to or larger than a predetermined value and a suppression quantity is set to suppress the advance of the shift ratio control so as to suppress the shift speed.
摘要:
A control apparatus for a power train including a continuously variable transmission and a clutch arranged in series with the continuously variable transmission is provided in which an engaging pressure of the clutch is first reduced until a slip occurs, and is then increased after detection of the slip so as to re-engage the clutch, and an engaging pressure of the clutch to be established is calculated by giving an excess pressure to the engaging pressure at which the clutch is re-engaged, such that an excess amount of the transmitted torque of the clutch is set smaller than that of the continuously variable transmission. The control apparatus is adapted to determine a learned value as a correction value of the engaging pressure that is set in advance in accordance with an input torque applied to the clutch, based on the engaging pressure calculated by giving the excess pressure to the engaging pressure at which the clutch is re-engaged.
摘要:
A control apparatus is provided for a vehicle including an internal combustion engine and a continuously variable transmission capable of controlling an output speed of the engine. A controller of the control apparatus determines a first operating point at which a total fuel consumption amount is minimized as an optimal operating point, such that the total fuel consumption amount is obtained by adding an amount of a fuel consumed by an exhaust purifying device disposed in an exhaust system to an amount of a fuel consumed by the engine for generating a required output. The controller then controls an engine load and also controls a speed ratio of the transmission so that the engine operates at the optimal operating point.
摘要:
An engine system includes an engine, continuously variable transmission and a controller. The engine has an engine shaft and plural cylinders. A number of activated cylinders among the plural cylinders is variable. The continuously variable transmission is configured to transmit a rotation of the engine shaft to wheels of a vehicle at a transmission ratio which is continuously variable. The controller is configured to control the engine to change the number of activated cylinders keeping an engine power generated by the engine to be substantially constant.
摘要:
In a power transmission system in a vehicle including a continuously variable gear path and a multi-stage gear path, a difference between gear ratios at the start of forward travel and at the start of backward travel is minimized, while using a single-pinion type planetary gear mechanism. The continuously variable gear path includes a forward/backward travel switching mechanism comprising a single-pinion type planetary gear mechanism, and a belt-type continuously variable transmission. A multi-stage gear path comprising gears is set at a gear ratio closer to a LOW side from that of the belt-type continuously variable transmission. Thus, when the forward traveling and the backward traveling are switched over from one to another, it is unnecessary to suddenly change the gear ratio of the belt-type continuously variable transmission, which can contribute to an improvement in durability of belt-type continuously variable transmission.
摘要:
There is provided a hydraulic transmission control system for a vehicle having an automatic engine stop/restart function. The hydraulic transmission control system includes a transmission having a power transmission element, an oil pump driven in synchronism with the engine to generate an oil pressure, a pressure regulator valve that regulates the oil pressure and supplies the regulated oil pressure to the power transmission element so as to allow power transmission through the power transmission element, and a control unit that operates the pressure regulator valve to control the oil pressure supplied to the power transmission element to a higher value when the vehicle is shifted from an automatic engine stop state to an automatic engine restart state, than that when the vehicle is in a normal driving state.
摘要:
A pressure reducing valve and a continuously variable transmission comprising an output pressure feedback loop operatively connected to provide proportional control of an output pressure of a flow of fluid passing through the pressure reducing valve in response to an input signal applied to a pilot stage control valve of the pressure reducing valve from an external source. The pressure reducing valve includes a main stage two-way spool valve having a valve body and a valve spool movable within the valve body in response to an imbalance of forces on the valve spool. The valve body has a supply port for receiving pressurized fluid from a source of constant hydraulic pressure and a load port for communicating a load pressure and flow from the spool valve to an actuator of the secondary pulley of the transmission to maintain transmission belt tension while preventing or minimizing belt slippage. The open area of the load port is dependent on the position of the valve spool within the valve body.