Drive train of a mobile vehicle

• US 8,818,662 B2
• Filed: 09/08/2011
• Issued: 08/26/2014
• Est. Priority Date: 09/28/2010
• Status: Active Grant

• Current Assignee: Linde Material Handling GmbH (Superlift Holding SARL)
• Original Assignee: Linde Material Handling GmbH (Superlift Holding SARL)
• Inventors: Welschof, Bernward, Langen, Alfred
• Primary Examiner(s): Moulis, Thomas
• Assistant Examiner(s): DALLO, JOSEPH J
• Application Number:
  US13/227,535
• Publication Number:
  US 20120078486A1
• Time in Patent Office: 1,083 Days
• Field of Search: 701/102, 701/103, 701/104, 701/110, 701/54, 701/50, 123/681, 123/436, 123/682, 123/687, 123/480, 123/492, 123/493
• US Class Current: 701/54
• CPC Class Codes: F02D 2200/1002 Output torque
• CPC Class Codes: F02D 2200/101 Engine speed
• CPC Class Codes: F02D 31/008 for idle speed control
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18
• CPC Class Codes: F02D 41/083 taking into account engine load variation, e.g. air-conditionning

Abstract

This invention relates to a drive train (1) of a mobile vehicle with an internal combustion engine (2) and a load device (3) driven by the internal combustion engine (2). The internal combustion engine (2) is controlled by an electronic engine control unit (4) and the load device (3) is controlled by an electronic control unit (5). A low idle speed (n_uL) for the operation of the internal combustion engine at no load is stored in the engine control unit (4). The electronic control unit (5) detects a pause in the operation of the load device (3) and transmits a speed setpoint (n_Standby) for standby operation of the internal combustion engine to the engine control unit (4) to operate the internal combustion engine (2) at idle during a pause in operation at the speed setpoint (n_Standby), which is below the low idle speed (n_uL) for standby operation.

Claims

1. A drive train of a mobile vehicle, comprising:

an internal combustion engine; and

a load device driven by the internal combustion engine and defining at least one operating function of the machine;

wherein the internal combustion engine is controlled by an electronic engine control unit and the load device is controlled by an electronic control unit,

wherein a low idle speed for operation of an unloaded internal combustion engine is stored in the engine control unit of the internal combustion engine,

wherein the electronic control unit recognizes a pause in the operation of the load device during which no operating function is activated, and during the pause in operation the electronic control unit transmits a speed setpoint (n_Standby) for standby operation of the internal combustion which is below the low idle speed (n_uL) to the engine control unit to operate the internal combustion engine at no load during a pause in operation at the speed setpoint (n_Standby) which is below the low idle speed (n_uL) for standby operation,

wherein the electronic control unit is in communication on an input side with at least one position encoder which, when an operating function is activated, emits an encoder signal for the operating function of the load device to the control unit, whereby the control unit recognizes a pause in operation when there is no encoder signal, and

wherein during the operation of the internal combustion engine at the speed setpoint (n_Standby) for standby operation and when an encoder signal from the position encoder is transmitted to the control unit for an operating function of the load device, the control unit transmits a required speed setpoint to the engine control unit for the operating function, wherein the control unit inhibits the start of the operating function of the load device until the internal combustion engine reaches low idle speed (n_uL).

2. The drive train of claim 1, wherein the control unit recognizes a pause in operation as a period in which there is no encoder signal and after the position encoder has not been actuated for a specifiable length of time.

3. The drive train of claim 1, wherein during operation of the internal combustion engine at the speed setpoint (n_Standby) for standby operation, the control unit prevents the application of a load to the internal combustion engine by an operating function of the load device.

4. The drive train of claim 1, wherein the control unit is in functional communication with a speed sensor device to capture an actual speed value of the internal combustion engine.

5. The drive train of claim 1, wherein the load device is a transmission device.

6. The drive train of claim 1, wherein the load device is a hydrostatic drive system with at least one of a hydrostatic traction drive and a hydraulic operating system with at least one hydraulic consumer.

7. The drive train of claim 1, wherein the operation function of at least one of the hydrostatic traction drive and of the consumers of the hydraulic work system is actuated electrically or electro-hydraulically and for actuation are in functional communication with the control unit.

8. The drive train of claim 1, wherein an equalization element is located in the drive train to equalize speed irregularities during standby operation of the internal combustion engine.

9. A method for the operation of a drive train of a mobile vehicle with an internal combustion engine and a load device driven by the internal combustion engine which defines at least one operating function of the machine, comprising:

controlling the internal combustion engine by an electronic engine control unit; and

controlling the load device by an electronic control unit, wherein a low idle speed for the operation of the unloaded internal combustion engine is stored in the engine control unit of the internal combustion engine, wherein for the reduction of the fuel consumption at idle of the internal combustion engine operating at no load, the internal combustion engine operating at no load is operated at a speed (n_Standby) for standby operation that is below the low idle speed (n_uL) stored in the engine control unit,

wherein in accordance with the request for an operating function by an actuation of position encoder that actuates the operating function, a speed required for the performance of the operating function is transmitted from the control unit to the engine control unit, the internal combustion engine is accelerated at maximum torque to the speed requested by the control unit and the control unit inhibits the execution of the operating function until the internal combustion engine, during acceleration from standby operation, has reached the low idle speed (n_uL).

10. The method of claim 9, wherein during a pause in the operation of the load device in which no operating function is actuated, a speed setpoint (n_Standby) for standby operation of the internal combustion engine which is below the low idle speed (n_uL) is transmitted from the electronic control unit to the engine control unit.