Recording a wear status for an operating medium and setting a replacement interval

p0001The present invention relates to a method for detecting a wear condition of an operating medium, in a vehicle transmission, in particular with a retarder, according to the closer defined in the preamble of claim 1. type. Moreover, the invention relates to an arrangement for determining a change interval of an operating medium of a vehicle transmission, in particular with a retarder, according to the closely defined in the preamble of claim 7 Art.

p0002For example, from the publication <patcit id="pcit0001" dnum="DE10057972A1"><text>DE 100 57 972 A1</text></patcit> discloses a method for the determination of evaluation parameters for transmission in vehicles. The evaluation parameters required are determined from measured parameters via sensors. As parameters, the vehicle weight, the rolling resistance, the number of starting operations of the vehicle, which was chargeable in a vehicle clutch friction work, the maximum occurring oil temperature or the operating time of transmission may be used. The measured values ​​are stored in a memory of the transmission control and can the driver or maintenance personnel are shown on a display. With the gained evaluation parameters of the career of the transmission can be documented and thus the emergence exhibited by damage in the transmission.

p0003Furthermore, from document <patcit id="pcit0002" dnum="DE102006015678A1"><text>DE 10 2006 015 678 A1</text></patcit> a method for determining the time of a required change for an operating medium, in particular oil, known during the operation of a drive unit. For this, a lifetime characteristic is predefined for the operating means used in the drive assembly. The temperature of the equipment is monitored during operation of the drive unit and sums the time of occurrence of a temperature of a certain size as a single loss to a total loss. It is predefined an intrinsic loss amount, wherein the determined amount of loss is compared with the limit amount of damage. Upon reaching the limit amount of damage a required change of the equipment is indicated for a specific temperature. Further, the remaining life can be calculated of the operating medium and visually displayed.

p0004The oil change intervals of gears are fixed usually prescribed and, depending on the mileage of the vehicle. As mentioned above takes the aging of the equipment at higher temperatures disproportionately. Under severe operating conditions, such as on construction sites, the change intervals of the equipment must be shortened. In contrast, at a lower load on the vehicle for a longer period of use of the equipment is possible. For cost and environmental reasons, it is desirable to obtain the longest possible service intervals. For gearboxes with retarder systems, the operating medium and the transmission oil in the braking mode is additionally heated and thus accelerates aging. Thus, the oil in the gear unit is highly dependent on the operating profile of the vehicle.

p0005The present invention addresses the problem of proposing a method for detecting a wear state of an operating medium of a vehicle transmission and an arrangement for determining a change interval of an operating medium of a vehicle transmission in which the shift timing of the operating medium is adjusted to a predetermined time.

p0006This object is achieved by the features of claim 1 or. 7 Further advantageous embodiments result from the dependent claims.

p0007Accordingly, a method for detecting a wear condition of an operating medium, in a vehicle transmission, in particular with a retarder, proposed, wherein the temperature of the operating medium is measured and in each case a current state of wear of the operating medium is ascertained to determine the remaining life of the operating medium. According to the operation of the vehicle transmission is influenced such that a scheduled maintenance timing of the operating medium coincides with the end of life of the working medium.

p0008In this way, by controlling the operation of the vehicle transmission or the retarder and the deterioration or the wear state are affected, so that consequently, as required, the end of life of the working medium can be varied with the operating medium used yet planned or desired shift timing to achieve, without the end of the life of the operating medium is reached before this time. Thus, an optimal utilization of the operating medium is realized with the inventive method.

p0009In order to determine the current aging or the current state of wear of the operating medium, such as the gear oil, it can be provided that the transmission oil temperature is continuously measured at a suitable location, for example at the outlet of the retarder. Use a collectivization of oil temperatures with a suitable calculation algorithm of the current damage state of the working medium or the transmission fluid can then be determined. This can include a life characteristic of the operating medium or other parameters are used.

p0010Especially with gearboxes with retarders aging or the wear of the working medium or the transmission oil is significantly on the operation pattern of the vehicle dependent. In particular, when used in high temperature environments and demanding topography, the oil is more damaged than when used on level ground, at normal ambient temperatures. When a scheduled change time point of the transmission oil is known, for example, at 500,000 kilometers driven the vehicle, the performance of the vehicle transmission or the retarder can be adjusted or limited in accordance with suitable algorithms. it when the scheduled change interval of the transmission oil coincides with a scheduled maintenance interval of the vehicle, in which, for example, the engine oil is changed and other services are performed is particularly advantageous. With the inventive method, it is possible that the selectable transmission oil change interval covers the maintenance intervals of the vehicle or is a multiple thereof.

p0011According to a possible embodiment of the present invention can be provided that in the context of influencing the driving of the vehicle transmission, the braking power of the retarder by means of suitable algorithms is varied accordingly, so that the planned target running time of the transmission oil is achieved. Preferably, the braking power of the retarder can be limited when the vehicle transmission in order to reduce the temperature of the transmission oil, and to prolong the life, if necessary.

p0012For example, when recognized that the damage of the transmission oil is less than anticipated in design, it is also possible that the braking power of the retarder is increased by the vehicle transmission in order to increase the temperature of the transmission oil, thus shortening the lifespan.

p0013A further advantageous embodiment of the invention may provide that the replacement time of the transmission oil is set manually and the braking power of the retarder control will be adjusted accordingly. In this way, set the time of the oil change itself and, depending on the increase or decrease the braking power of the retarder either as the operator.

p0014The basis of the invention is solved by an arrangement for determining a change interval of an operating medium of a vehicle transmission, in particular with a retarder, wherein an input device is provided for inputting predetermined operating parameters. According to the invention may be as an input device, a switch or the like provided on a dashboard of the vehicle to determine whether a longer change interval with reduced braking power of the retarder or a shorter replacement interval is used with no loss of braking power of the retarder. Thus, a user-side setting is d it change interval or the time to change possible.

p0015By the present invention, a diagnosis of the deterioration or wear of an operating medium, such as the transmission oil, are made possible to provide an appropriate actuation strategy of the vehicle transmission, in particular of the retarder thereof. Thus, the remaining life can be adapted to a desired change time point of the transmission fluid or to a scheduled maintenance time of the vehicle.

p0016Preferably, the proposed arrangement can be combined with the method according to the invention, so that the information obtained is processed and evaluated as part of the process of the assembly in order to optimize the resulting control strategy of the vehicle transmission or the retarder.