摘要:
An adjustable pulley for use in a continuous variable transmission in the power train of a motor vehicle has an axially fixed first conical flange and an axially movable second conical flange. The hydraulic control system which moves the second flange relative to the first flange is provided with at least one first plenum chamber which receives pressurized fluid when the second flange is to move toward the first flange, and with an additional plenum chamber which receives pressurized fluid when the second flange is to move away from the first flange. The admission of pressurized fluid into the additional chamber is regulated in dependency upon the RPM of the flanges. Rapid evacuation of pressurized fluid from the additional chamber can take place by way of a relief valve which opens when the pressure of fluid in the additional chamber rises to a preselected value. This renders it possible to rapidly shift between overdrive and underdrive.
摘要:
The invention relates to a method for manual control of the ratio of a continuously variable transmission (CVT) for a vehicle. The CVT has one control device, one shifting or selector device, one starting element and one variator for ratio adjustment and is driven by an internal combustion engine. The control device processes input signals derived from a driver-vehicle system within the scope of an operating strategy under the control of the reduction ratio, the rotational speed of the prime mover, or an input rotational speed of the variator. The operation strategy automatically selects in an automatic operating mode the transmission ratio. In a manual operating mode, the driver can engage directly in the selection of the transmission ratio via the shift or selector device. It is proposed that in the operating mode there is manually preset a signal proportional to the vehicle speed which is further processed as a theoretical guidance for the operating point of the engine-transmission unit. The speed-regulating device controlled on the transmission side can be combined within the manual operating mode with the direct engagement in the selection of the transmission ratio.
摘要:
Leak oil from a regulator 24 for regulating the pressure of oil supplied to a lubricating system (the lubricating pressure) is supplied to an oil cooler 23. An electromagnetic valve 25 is connected to a pressure controlling and regulating oil chamber 24a of the regulator 24 so that the lubricating pressure can be controlled to be increased or decreased. The lubricating pressure is decreased while an engine is running in a low load state during a high-speed running to thereby increase the volume of oil to be supplied to the oil cooler 23.
摘要:
In an apparatus for controlling a pulley side-pressure of a belt type continuously variable transmission mechanism provided, in series with a starting clutch, in a transmission of a vehicle having a function of stopping engine idling so that an engine is automatically stopped, if the vehicle start-up is controlled from the state of engine stopping in an ordinary way in which the pulley side-pressure is determined by that belt transmission torque corresponding to an output torque of the engine which is obtained by the rotational speed and the negative suction pressure of the engine, the pulley side-pressure becomes excessive by wrong judgement that the engine output torque is large, because the negative suction pressure is small at the beginning of the engine starting. The durability then deteriorates and the specific fuel consumption becomes poor. As a solution, at a vehicle start-up from the state of engine stopping, a belt transmission torque corresponding to that transmission torque of the starting clutch which is obtained by the engaging force of the starting clutch is compared with a belt transmission torque corresponding to the engine output. The pulley side-pressure is each controlled based on that transmission torque of the drive pulley corresponding to the smaller belt transmission torque and on the transmission torque of the driven pulley.
摘要:
In a control apparatus for an automotive continuously variable transmission having a forward-reverse selector mechanism in which a gear ratio for reverse is set closer to a speed reducing side than a gear ratio for forward and a belt type continuously variable transmission mechanism, a PH pressure that is outputted from a first regulator valve and a PL pressure that is outputted from a second regulator valve are changeably supplied to one and the other of a hydraulic cylinder of a drive pulley and a hydraulic cylinder of a driven pulley via a shift control valve. A hydraulic pressure supplied to a reversing hydraulic pressure connecting element from a reversing manual valve is inputted into an oil chamber of a first regulator valve so that the PH pressure is increased with the hydraulic pressure so inputted.
摘要:
A shift control system comprises a diameter-change calculation which calculates the difference between the diameters of the contact circles at present and after a shift to a target speed change ratio and a slip prevention thrust calculation which calculates a slip prevention thrust necessary for transmitting the power through a V belt without slip between the V belt and the drive and driven pulleys. A speed ratio maintaining thrust calculation which calculates a speed ratio maintaining thrust that is an addition to the slip prevention thrust for maintaining the current speed change ratio in constant condition and for transmitting the power without any slip of the belt and a additional thrust calculation which calculates a shifting additional thrust that is added for a contact-circle enlarging pulley to achieve a shift to the target speed change ratio.
摘要:
Engine torque control system based on the dynamic behavior of a driven automatic transmission consists in that the engine dynamics is limited as function of a sporting mode.
摘要:
A drive unit with a continuously variable cone-pulley transmission as used particularly in motor vehicles comprises a pressure valve and an OR-gate valve with slide pistons sharing a common valve bore. An interposed push member serves to reduce or eliminate transverse forces between the slide pistons.