METHOD FOR OPERATING A TRANSMISSION DEVICE, AND CORRESPONDING TRANSMISSION DEVICE

Abstract

A method for operating a transmission device and a transmission with at least one oil chamber, in which is arranged a wheelset of the transmission device. At the same time, in order to determine the temperature in the oil chamber, an overall level is determined for the oil chamber, wherein an initial value is determined from the overall energy level at the start of the operation of the transmission device with the following steps: determination of a standardized shutdown time as a function of an external temperature and of the overall energy level that is present with the shutdown of the transmission device, determination of a corrected shutdown time as a function of the standardized shutdown time and a measured shutdown time, and determination of the initial value as a function of the corrected shutdown time and of the momentary external temperature.

Claims

1-10. (canceled)

11. A method for operating a transmission device provided with at least one oil chamber, in which is arranged a wheelset of the transmission device, wherein in order to determine the temperature in the oil chamber, an overall energy level is determined for the oil chamber, wherein an initial value is determined for the overall energy level at the start of the operation of the transmission device comprising the following steps: determining a standardized shutdown time as a function of an external temperature and of the overall energy level that is present at the shutdown of the transmission device, determining a corrected shutdown time as a function of the standardized shutdown time and of a measured shutdown time, and determining an initial value as a function of the corrected shutdown time and of the momentary external temperature.

12. Method according to claim 11, wherein the overall energy level is set to be equal to the initial value at the start of the operation.

13. Method according to claim 11, wherein during an operation of the transmission device, the overall energy level is periodically incremented by the supplied energy and decremented by the discharged energy.

14. Method according to claim 11, wherein the supplied energy is determined as a function of a loss torque of the transmission device, of the rotational speed and of a time difference.

15. Method according to claim 11, wherein the supplied energy is determined as a function of the overall energy level and of the temperature of an adjacent oil chamber.

16. Method according to claim 11, wherein the discharged energy is determined as a function of the external temperature, of a driving speed and of the overall energy level.

17. Method according to claim 11, wherein different external temperatures are applied in order to determine discharged energy from a plurality of output characteristic diagrams for different external temperatures in dependence on the driving speed and the overall energy level for extracted raw energy, and to create a raw energy characteristic diagram.

18. Method according claim 11, wherein after creating the raw energy characteristic diagram, the raw energy extraction is read from the raw energy characteristic diagram while using external temperature.

19. Method according to claim 11, wherein the discharged energy corresponds to the energy extraction, or is determined from a correction factor, wherein the correction factor is determined from the operating state of an oil pump that is fluidically associated with the oil chamber.

20. A transmission device, comprising: at least one oil chamber, in which is arranged a wheelset of the transmission device, wherein the transmission device is designed to determine the temperature in the oil chamber so as to determine an overall level for the oil chamber, wherein an initial value is determined for the overall energy level at the start of the operation of the transmission device with the determination of a standardized shutdown time as a function of an external temperature and of the overall energy level that is present at the shutdown of the transmission device, determination of a corrected shutdown time as a function of the standardized shutdown time and of a measured shutdown time, and determination of an initial value as a function of the corrected shutdown time and of the momentary external temperature.

Description

[0037] The invention will now be explained with respect to the embodiments illustrated in the FIGURE, without limiting the invention in this manner. The single FIGURE shows:

[0038] a flowchart indicating a method for operating a transmission device, in particular in order to determine an overall energy level for an oil chamber of the transmission device.

[0039] The figures shows a flowchart illustrating a method for operating a transmission device. The transmission device is preferably a gearbox device, in particular an automatic transmission device. The transmission device is preferably a constituent of a motor vehicle, or more specifically of a drivetrain of a motor vehicle. The transmission device is in this respect on the one hand operatively connected or can be operatively connected with a drive device of the motor vehicle, and on the other hand it is operatively connected with at least one drivable axle of the vehicle.

[0040] The transmission device is provided with an oil chamber in which is arranged a wheelset of the transmission device. The wheelset is equipped with at least one gear transmission, for example a spur gear, a bevel gear and/or a planetary gear. In particular, the wheel set is provided with several such gear transmissions. In addition to this oil chamber, another oil chamber is also provided, arranged so that it is adjacent to the oil chamber. In this adjacent oil chamber is arranged at least one actuator, which is used in particular for adjusting to a desired transmission ratio at the transmission device. For this purpose, the activator is for example connected with the wheelset of the transmission device.

[0041] A lubricant or oil is supplied both to the oil chamber and to the adjacent oil chamber. The oil chamber is for this purpose preferably provided with dry sump lubrication. This can be provided also in the case of the adjacent oil chamber.

[0042] In order to determine the temperature in the oil chamber, an overall energy level is determined for the oil chamber. The method described with reference to the process flow diagram is used for this purpose. Within the context of a step 1, the overall energy level to be determined is first set so that it is either equal to a stored overall energy level, or—if the determination follows immediately the start of the operation of the transmission device—so as to be equal to an initial value for the overall energy level.

[0043] The initial value is described as follows: First, a standardized shutdown time is determined. As input variables for the characteristic diagram 2 is in this case used an external temperature and the overall energy level, which was present immediately when the transmission device was previously shut down. The standardized shutdown time T.sub.n is determined from the characteristic diagram 2. A measured shutdown time T.sub.A is derived from this value, so that the result is provided as a corrected shutdown time T.sub.k. This is then again applied, in addition to the momentary external temperature, as an input variable for the characteristic diagram 3. From this is then derived the initial value for the overall energy level. As was already mentioned, the overall energy level is set at the start of operations to equal the initial value as soon as this value is determined.

[0044] During the operation of the transmission device, the overall energy level is incremented starting from the value determined in step 1 by the supplied energy and decremented by the discharged energy. The former is determined at least partially within the context of step 4, wherein the supplied energy is obtained form a function wherein as input variables are used a loss torque of the transmission device, the rotational speed, and a time difference.

[0045] This can be based for example on the following formula:

E.sub.1=M.sub.loss.Math.n.sub.input/9550.Math.Δt

wherein E corresponds to the supplied energy, M.sub.loss corresponds to the loss torque of the transmission device, and n.sub.input corresponds to the input rotational speed and Δt is the time difference between immediately successive points in time at which the supplied energy is determined or the overall energy level is updated.

[0046] The supplied energy E.sub.1 is applied within the context of step 5 to the overall energy level. After that, the discharged energy is determined. Several output characteristic diagrams 6 are provided for this purpose, each of which takes into account a raw energy extraction for different external temperatures for a driving speed and sets the overall energy level.

[0047] In this respect, a value is read from the output characteristic diagram 6 for the raw energy extraction, wherein this is done in dependence on the driving speed and on the overall energy level. The values that are read out from the output characteristic diagram 6 are then applied in a raw energy characteristic diagram 7 in dependence on the different external temperatures. From each output characteristic diagram 6 will therefore result a certain value for the raw energy extraction for a certain external temperature.

[0048] In the raw energy characteristics diagram 7 is now each of these values applied for the raw energy extraction above the respective value of the external temperature. After creating the raw energy characteristic diagram 7, the raw energy extraction E.sub.R is read out from the raw energy characteristic diagram 7, wherein the momentary external temperature serves as an input variable. In addition, a correction factor k is determined, for example by means of another characteristic diagram 8. For example, linear interpolation is used when reading from the raw energy characteristic diagram 7 and/or the next characteristic diagram 8. The discharged energy E.sub.2 now is now obtained from a multiplication of the raw energy extraction and the correction factor k, resulting in the following formula:

E.sub.2=E.sub.r.Math.k.Math.

[0049] The correction factor k can be determined from an operating state of an oil pump that is fluidically associated with an oil chamber. For example, the correction factor is related to the rotational speed of the oil pump. The derived energy E.sub.2 determined in this manner is deducted within the context of step 9 from the overall energy level.

[0050] Finally, another part of the supplied energy, which is here referred to as E.sub.3, is determined from the overall energy level and from a temperature of the adjacent oil chamber. For this purpose is used for example the characteristic diagram 10. The supplied energy E.sub.3 is again supplied to the overall energy level within the context of step 11. If the overall energy level is considered as an input variable for the use of the overall energy level within the context of the present description, then this always means the value of the overall energy level which is present during step 1 or immediately after step 1.

[0051] A new value is thus obtained with the procedure described above for the overall energy level, which is then stored. After that, the procedure described here is periodically repeated so that for example after a certain time period, the procedure is branched back to step 1. Because during the operation of the transmission device, only one value is present for the overall energy level, the determination of the initial value does not have to be carried out again, so that the overall energy level that was present for the overall energy level within the context of step 12 is then set within the context of step 1.

[0052] When the transmission device is turned off, or when the operation is finished, the overall energy level and the current temperature are stored, in particular in a storage device of the transmission device.

[0053] A cost-effective and reliable method for determining the temperature in the oil chamber is thus implemented by using the procedure described above. In particular, a possibility described here is to bridge over time the period when the transmission device is idle, while an accurate estimate of the temperature required for an overall energy level can still be carried out at the same time.