DE102006019904A1 - Adjustment method for conversion during reverse travel of drive, involves accomplishing change of conversion of variator of drive during reversal travel - Google Patents

Abstract

The method involves accomplishing a change of conversion of a variator of a drive during reversal travel. The variator has a gear wheel arrangement for actual reversal. The adjustment of conversion during reverse travel takes place by the starting of a target-input speed depending on the driving speed. An engine intervention is accomplished in the form of a vehicle-speed-dependent engine moment reduction additional to the variator adjustment.

Description

The The invention relates to a method for adjusting the translation a gearbox comprising a variator when reversing, according to the preamble of claim 1

at infinitely variable transmissions is to change the direction of travel in general, a suitable arrangement of gears with constant translation intended. For example, in CVT cars, this is the variator upstream or downstream planetary gear set, usually as a single or Double planetary set executed is. In this case, the variator can be a looping means (push belt, Chain) or as a toroid variator accomplished be. When driving forward In general, the arrangement for reversing the direction of travel is bridged.

at reversing is held in the state of the art, the variator in the "LOW" position, which the speed exclusively via the engine speed is set and thus upwards by the Abregeldrehzahl of the motor is limited. This is given for design reasons given translation the arrangement for reversing the direction in the slow (simple planetary gear as Arrangement for reversing direction) of disadvantage, since thereby the usual speeds when reversing can not be achieved can. Another disadvantage is the noise, which is particularly is strong when the arrangement to reverse the direction of travel in front of the variator is arranged, resulting in a deterioration of the ride comfort. Furthermore, the torque-transmitting Components that are located between variator and output strong loaded.

Of the The present invention is based on the object, a method to set the translation indicate a gearbox comprising a variator when reversing through the execution a reduction in the load between the variator and the output arranged torque-transmitting Components is achieved. Furthermore, the noise should be reduced and the achievement of accustomed or higher speeds reversing allows become.

These The object is solved by the features of claim 1. Further Embodiments of the invention and advantages are apparent from the dependent claims.

Therefore is a method of adjusting the translation of a variator comprehensive gearbox when reversing proposed, in the context of which when reversing a change the translation the variator of the transmission is carried out quickly.

Thereby are the output-side components by reduced to be transmitted Moments protected at comparable driving condition. In particular, at a variator downstream arrangement for reversing the direction of travel, in reverse by the change proposed according to the invention the translation of the variator quickly, the arrangement for reversing the direction of travel reduced to be transferred Moments protected at comparable driving condition.

In addition will the ride comfort by the inventively achievable reduction of Engine speed increased in an advantageous manner, since the reduction of Engine speed results in a reduced noise.

One Another advantage is that through the change the translation Variator quickly the usual or a higher speed can be achieved.

The Setting the translation in reverse can according to the invention by specifying a desired input speed as a function of the driving speed.

This is particularly advantageous if the direction of rotation reversal by ins Slow translated Gear arrangements takes place, as for example in a Variator upstream or downstream single planetary gear set of Case is. This sets the output speed on the variator when reversing advantageously no longer in a fixed relationship to Engine speed.

By the proposed translation change in reverse if necessary, too fast vehicle speeds are reached. For this reason, it is proposed, in addition to variator adjustment an engine intervention in the form of a vehicle speed-dependent engine torque reduction perform. Here, e.g. with increasing speed the maximum permissible engine torque reduces, thereby limiting the speed reached becomes.

Claims (4)

Method for adjusting the gear ratio when reversing a gear comprising a variator, which for reversing the direction of rotation has a slow translating gear arrangement, characterized in that when reversing a change in the ratio of the variator of the transmission is carried out quickly. Method according to claim 1, characterized in that that the setting of the translation in reverse by specifying a target input speed in dependence from the driving speed. Method according to claim 1 or 2, characterized that in addition for Variatorverstellung an engine intervention in the form of a vehicle speed-dependent engine torque reduction carried out becomes. Method according to claim 3, characterized that with increasing speed the maximum permissible engine torque is reduced, thereby limiting the speed becomes.