摘要:
In one aspect, a method (100) for automatically calibrating clutches within a transmission (24) of a work vehicle (10) may include determining, whether a plurality of predetermined conditions are satisfied for performing a clutch calibration on a clutch of the transmission (102). The predetermined conditions may require that the work vehicle (10) be in park (102A) and that a predetermined time period has elapsed since a previous clutch calibration was performed on the clutch (102B). In addition, the method may include automatically initiating the clutch calibration without requiring operator input (104) when the predetermined conditions are satisfied and performing the clutch calibration in order to calibrate the clutch (106).
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:
The present invention aims to enable the accurate learning of a true torque point in a wet friction clutch (3), prevent the clutch connection shock by absorbing the response delay upon an ordinary clutch connection control, and to successfully combine the time lag and shock. In the present invention, the value (D) itself of the duty ratio of the duty pulse output from the ECU (16) is learned as the torque point (Dm). In a power transmission device of a vehicle having a fluid coupling (2) and the wet friction clutch (3)provided in series between the engine (E) and transmission (T/M), the value (Dm) of the duty ratio at the time when the clutch input side revolution (Nt) decreases to a value lower than the engine revolution (Ne) by a prescribed revolution (Nm) during the process of gradually connecting the clutch 3 is learned as the torque point. Preferably, learning is conducted after the elapse of a prescribed waiting time (Δt1). During an ordinary clutch connection control, a prescribed start duty (Dst0) for connecting the clutch (3) broadly up to a point close to the torque point (Dtb) is initially output from the ECU (16), and a gradual duty (Dk) is output after retaining such start duty (Dst0) for a prescribed time (Δt3). Preferably, a first gradual duty (Dk1) for gradually connecting the clutch quickly is output, and a second gradual duty (Dk2) for gradually connecting the clutch slowly is output thereafter.
摘要:
This invention provides automatic and reliable determination of the touch point of a clutch controlled by an automatic clutch actuation controller. This invention determines the touch point upon power-up while idling the engine, with the transmission in neutral and an input shaft brake applied. The clutch actuation controller gradually engages the clutch so that the measured transmission input speed matches a reference speed signal preferably between 40% and 60% of the idle speed. If the actuation is slow enough, this reliably provides the degree of clutch engagement at a small torque matching the braking torque which is the touch point. If there is no previous knowledge of the touch point, the clutch is applied at a fast rate and an approximate touch point is determined, then the clutch is positioned below the approximate touch point and is again applied at a slow rate to more accurately ascertain the touch point. If there is previous knowledge of the touch point, the clutch is positioned just below the old touch point and is applied at a slow rate to determine a new touch point. The new and old touch points may be combined to determine the updated touch point.
摘要:
This invention provides automatic and reliable determination of the touch point of a clutch controlled by an automatic clutch actuation controller. This invention determines the touch point upon power-up while idling the engine, with the transmission in neutral and an input shaft brake applied. The clutch actuation controller gradually engages the clutch so that the measured transmission input speed matches a reference speed signal preferably between 40% and 60% of the idle speed. If the actuation is slow enough, this reliably provides the degree of clutch engagement at a small torque matching the braking torque which is the touch point. If there is no previous knowledge of the touch point, the clutch is applied at a fast rate and an approximate touch point is determined, then the clutch is positioned below the approximate touch point and is again applied at a slow rate to more accurately ascertain the touch point. If there is previous knowledge of the touch point, the clutch is positioned just below the old touch point and is applied at a slow rate to determine a new touch point. The new and old touch points may be combined to determine the updated touch point.
摘要:
This invention provides automatic and reliable determination of the touch point of a clutch controlled by an automatic clutch actuation controller. This invention determines the touch point while idling the engine, with the transmission in neutral and an inertial brake applied. The clutch actuation controller engages the clutch so that the measured transmission input speed matches a reference speed signal preferably between 40% and 60% of the idle speed. This reliably provides the degree of clutch engagement at a small torque matching the braking torque. When the transmission input speed is within a predetermined amount of the reference speed signal, such as 4%, this invention determines the clutch touch point corresponding to the degree of clutch engagement. This degree of clutch engagement may be a clutch position signal or a clutch pressure signal produced by an existing sensor used in the automatic clutch control. If no measured clutch engagement signal is available, this degree of clutch engagement may be the clutch engagement signal used to control the degree of clutch engagement. The touch point is set as the difference between this degree of clutch engagement for the small torque and a clutch touch point offset.