Operating method for a vehicle drive train of a working machine including a drive motor, a transmission and an output

Patent metadata

Field	Value
Publication number	US-10358135-B2
Application number	US-201715405371-A
Country	US
Kind code	B2
Filing date	Jan 13, 2017
Priority date	Jan 14, 2016
Publication date	Jul 23, 2019
Grant date	Jul 23, 2019

Abstract

A method for the operation of a vehicle drive-train of a working machine having a drive motor, a transmission whose transmission ratio can be varied continuously, and a drive output. A rotational speed (nmot) of the drive motor can be varied by the driver, by the driver's actuation of a first control element ( 50 ), within a rotational speed range ( 53 ) delimited by an upper characteristic line (nmoto) and a lower characteristic line (nmotu). The characteristic lines (nmoto, nmotu) are functions of a reciprocal transmission ratio (irez) of the transmission. Furthermore, the rotational speed (nmot 1 ) of the drive motor that can be set by the driver by way of the first control element ( 50 ), can be influenced by the driver's actuation of a second control element ( 51 ) and as a function of an operating condition of the working machine.

First claim

The invention claimed is:

1. A method of operating a vehicle drive-train of a working machine, the working machine having a drive motor, a transmission whose transmission ratio can be varied continuously, a drive output, and a rotational speed of the drive motor being variable by a driver, via a first control element, within a rotational speed range delimited by an upper characteristic line and a lower characteristic line, the method comprising:
the upper and the lower characteristic lines are functions of a reciprocal transmission ratio of the transmission, which corresponds to a quotient of a value of the rotational speed of the drive output and a value of the rotational speed of the drive motor,
adjusting the rotational speed of the drive motor by the driver via the first control element;
influencing the rotational speed via the driver's actuation of a further control element and as a function of an operating condition of the working machine; and
selecting a rotational speed value from a characteristic line which, depending on the operating condition of the working machine, is multiplied by a weighting factor that varies between 0 and 1 as a function of the operating condition of the working machine such that the upper characteristic line is influenced as a function of a weighted rotational speed value.

2. The method according to claim 1 , further comprising varying the upper characteristic line by the driver's actuation of the further control element and as a function of the operating condition of the working machine.

3. The method according to claim 1 , further comprising varying the rotational speed of the drive motor selected as a function of the actuation of the first control element by the driver's actuation of the further control element and as a function of the operating condition of the working machine.

4. The method according to claim 3 , further comprising, depending on the actuation of the further control element, selecting a rotational speed value from a characteristic line, which is multiplied by a weighting factor that varies between 0 and 1 depending on the operating condition of the working machine, and is then added to the rotational speed of the drive motor (2) selected as a function of the actuation of the first control element.

5. The method according to claim 1 , further comprising with increasing actuation of the first control element while at the same time the rotational speed of the drive output is low, the weighting factor increases, whereas the weighting factor decreases as the value of the rotational speed of the drive output increases.

6. The method according to claim 1 , further comprising the weighting factor decreases with an increasing reciprocal transmission ratio of the transmission.

7. The method according to claim 1 , further comprising with increasing swivel angle of a hydraulic adjustment unit of a hydrostatic variator of the transmission, in an area of which the transmission ratio of the transmission can be varied continuously, and a thereby increasing displacement volume of the adjustment unit that can be operated as a motor, the weighting factor decreases.

8. The method according to claim 1 , further comprising with an increasing pressure difference between a high-pressure side and a low-pressure side of a hydraulic adjustment unit of a hydrostatic variator of the transmission, in an area of which the transmission ratio of the transmission can be varied continuously, the weighting factor increases.

9. The method according to claim 1 , further comprising varying the rotational speed of the drive motor selected as a function of the actuation of the first control element and of the further control element as well as of the operating condition of the working machine, as a function of an actuation of an additional control element.

10. The method according to claim 9 , further comprising, depending on the actuation of the additional control element, selecting a rotational speed change value, which is added to the rotational speed of the drive motor determined as a function of the actuation of the first control element and of the further control element as well as of the operating condition of the working machine.

11. The method according to claim 9 , further comprising:
depending on the actuation of the additional control element, selecting a rotational speed value, and
determining in each case a maximum of the rotational speed value selected as a function of the actuation of the additional control element and the rotational speed determined as a function of the actuation of the first control element and of the further control element as well as of the operating condition of the working machine,
the maximum in each case corresponds to the rotational speed value of the rotational speed of the drive motor determined as a function of the actuation of the additional control element.

12. The method according to claim 9 , further comprising limiting the rotational speed of the drive motor, determined in each case as a function of actuation of the additional control element, to a maximum permissible value of the input rotational speed of the transmission.

13. A method of operating a vehicle drive-train of a working machine, the working machine having a drive motor, a transmission with a transmission ratio that is continuously variable, and a drive output, the method comprising:
varying a rotational speed of the drive motor, within a rotational speed range, by actuating a first control element, and delimiting the rotational speed range by an upper characteristic line and a lower characteristic line;
defining both the upper and the lower characteristic lines as functions of a reciprocal transmission ratio of the transmission, which corresponds to a quotient of a value of the rotational speed of the drive output and a value of the rotational speed of the drive motor;
varying the rotational speed of the drive motor; and
varying the upper characteristic line by actuating a further control element and as a function of an operating condition of the working machine.

14. A method of operating a vehicle drive-train of a working machine, the working machine having a drive motor , a transmission which can be varied continuously, a drive output, and a rotational speed of the drive motor being variable by a driver, via a first control element, within a rotational speed range delimited by an upper characteristic line and a lower characteristic line, where the upper and the lower characteristic lines are functions of a reciprocal transmission ratio of the transmission, which corresponds to a quotient of a value of the rotational speed of the drive output and a value of the rotational speed of the drive motor, the method comprising:
adjusting, by the driver via the first control element, the rotational speed of the drive motor within the upper characteristic line and the lower characteristic line; and
influencing the rotational speed and varying the upper characteristic line via the driver's actuation of a further control element and as a function of an operating condition of the working machine.

Assignees

• Zahnradfabrik Friedrichshafen

Inventors

• Hiemer Marcus
• Kuhn Jan-Frederik
• Schinacher Stephan
• Bieber Sven
• LEGNER JüRGEN

Classifications

• F02D2200/101

  Engine speed · CPC title

• B60W30/1882 Primary

  characterised by the working point of the engine, e.g. by using engine output chart · CPC title

• F02D2200/602

  Pedal position · CPC title

• Y10T477/623

  Cross-Sectional Technologies · mapped topic

• F02D29/02

  peculiar to engines driving vehicles; peculiar to engines driving variable pitch propellers · CPC title