Abstract:
Bei einem automatischen Getriebe (17), insbesondere bei einem stufenlosen Umschlingungsgetriebe eines Kraftfahrzeugs können Situationen auftreten, bei denen Vorgaben für eine Übersetzungsänderung nicht umgesetzt werden können. Der Grund liegt dabei in einer ungenügenden Versorgung eines Hydrauliksystems (47, 48, 49, 50, 51, 52, 53, 54) mit Hydraulikfluid. Es ist Aufgabe der Erfindung eine Steuerungseinrichtung vorzuschlagen, welche eine ausreichende Versorgung des Hydrauliksystems (47, 48, 49, 50, 51, 52, 53, 54) mit Hydraulikfluid in möglichst vielen Fahrsituationen des Kraftfahrzeugs ermöglicht. Erfindungsgemäß wird in Abhängigkeit einer Abweichung zwischen der Vorgabe der Änderung und der tatsächlichen Änderung oder einer Abweichung zwischen der Vorgabe und einer Änderungs-Kenngröße, welche eine maximal mögliche Änderung der Übersetzung des Getriebes (17) kennzeichnet, eine Mindestdrehzahl der Antriebsmaschine (11) eingestellt. Damit wird eine ausreichende Versorgung mit Hydraulikfluid gewährleistet.
Abstract:
Die Erfindung geht aus von einer Vorrichtung mit einer Einheit (10), die zum Betätigen eines stufenlosen Kraftfahrzeuggetriebes (11) in wenigstens einem Normalmodus (N) und in einem Beschleunigungsmodus (B) mit einer im Vergleich zum Normalmodus (N) höheren Antriebsdrehzahl (ω A ) vorgesehen ist. Es wird vorgeschlagen, dass die Einheit (10) zur Anpassung eines Differenzwerts (δω A ), um den die Antriebsdrehzahl (ω A ) im Beschleunigungsmodus (B) im Vergleich zum Normalmodus (N) höher ist, abhängig von einer Beschleunigung (a) eines Kraftfahrzeugs (12) vorgesehen ist.
Abstract:
Bei einem Verfahren zum Vermindern eines Umschaltungsrucks eines CVT-Getriebes mit Leistungsverzweigung schwächt ein durch kurzzeitige Variatorverstellung hervorgerufener Auslösungsruck den durch die Bereichsumschaltung hervorgerufenen Ruck. Bei einem weiteren Verfahren wird die Betätigung der die Bereichsumschaltung herbeiführenden Umschaltkupplungen entsprechend sich bei der Bereichsumschaltung ergebenden Drehmassenbeschleunigungen modifiziert.
Abstract:
The invention relates to a method for operating the drive device of a vehicle. The drive device of a motor vehicle that comprises an engine and a continuously variable automatic transmission for driving the driven wheels of a vehicle is usually operated in a normal mode in normal driving operation and in a brake-engaging mode if the slip acting upon at least one of the wheels exceeds a determined value. During the brake-engaging mode the transmission ratios may vary widely or the vehicle may run at a low engine torque but high drive speed, which is often disagreeable for the driver. The aim of the invention is to provide a method with which the driving comfort is improved. To this end, a normal transmission ratio is given in the normal mode as the desired value of the transmission ratio and the transmission ratio is reduced to an actual transmission ratio in the brake-engaging mode. The difference between the normal transmission ratio and the actual transmission ratio is detected as the differential ratio and a maximum desired drive speed is modified depending on the differential ratio.
Abstract:
The invention relates to a method for controlling the multiplication for a continuously variable transmission with electrohydraulic drive using a control loop having a linear PID controller with the specified multiplication of the variator iv_soll serving as a command variable, with the actual multiplication iv serving as a regulating variable, and with the multiplication changing speed serving as a correcting variable. According to the invention, the correcting variable supplied by the PID controller is limited to limiting values, said limiting values being determined by the design, for an upshift and downshift, whereby these limiting values can be calculated from the limits determined by construction and from the operating point-dependent limits determined by volume flow, and the intersection of both permissible intervals determined by construction and by volume flow is defined as a permissible multiplication changing speed range.
Abstract:
The invention relates to a method and device for a coupling (2) in a motor vehicle transmission, said coupling being controlled and regulated during two operational states by means of a first regulating circuit (3). The regulated quantity corresponds to the actual value of a differential engine speed of said coupling (2). Said first state corresponds to a starting action and said second state to operation with a variable transmission ratio.
Abstract:
The invention relates to a control system for a continuously variable transmission, controlling the lock-up clutch (10) of a torque converter (2) in particular. The lock-up clutch (10) is controlled according to a strategy whereby the torque converter (2) is considered as being serially mounted with the continuously variable transmission (17). Engagement or disengagement of the lock-up clutch (10) is exclusively a function of the control of the theoretical engine speed.
Abstract:
The invention relates to a method of adjusting the transmission ratio of a continuously variable gear. The position of a current operating point (B_akt) in a predetermined driving range is constantly adjusted in accordance with the driving situation. The position of the operating point is also determined by range boundaries (UG, OG) which can be varied in accordance with the driving resistance and driver's manner of driving. The method is characterised in that it simplifies development and application.
Abstract:
The control (1) may be used in particular to control an automatic vehicle gearbox. Depending upon the accelerator depression, the vehicle speed or other quantities measured, a setting signal STS is established by means of which the gear to be selected or the transmission ratio to be set is determined. The control (1) has a classification system (4) to which the quantities measured and parameters derived therefrom are supplied as input values and, on the basis of an assessment of the quantities measured and parameters, output variables are generated by means of which the current running state or load state of the vehicle and the driving conduct of the driver are taken into account according to given assignments. The control (1) contains an evaluation circuit (14) in which an action signal generated by a manual action by the driver is assessed and then one of the predetermined relations is altered by the transmission of an assessment signal EBS. Here it is possible to switch off partial functions of the control (1) or modify important stored parameters of partial functions without putting it completely out of action.
Abstract:
Control system for a Continuously Variable Transmission with two pairs of conical sheaves each with an adjustable running radius, the sheave of each pair being coupled to a hydraulic actuator and the inlet port of each actuator being connected with the hydraulic actuator setting means, fed from the outlet port of a hydraulic displacement pump, connected to a supply of hydraulic medium and coupled to an electric motor which is controlled by a controller which controls the speed of the electric motor with a first control signal which is generated as a function of the actual transmission ratio of the transmission on one hand and of the desired speed of change of this transmission ratio on the other hand, all this in such a way that the speed of this first motor increases with an increase of the transmission ratio of the transmission on one hand and an increase of the speed of change of the ratio on the other hand, while the outlet port of the displacement pump is connected to the inlet of an electronically controllable pressure relief valve of which the set point is determined by a second control signal as a function of the set transmission ratio on one hand and the value of the actual torque transmitted through the transmission on the other hand, in such a way that de value of the resulting hydraulic pressure increases as the transmission ratio increases on one hand, and as the torque transmitted through the transmission increases on the other hand.