Electrical gas pedal

• US 4,850,320 A
• Filed: 05/13/1988
• Issued: 07/25/1989
• Est. Priority Date: 07/09/1987
• Status: Expired due to Term

• Current Assignee: VDO Adolf Schindling AG (Vodafone Group PLC)
• Original Assignee: VDO Adolf Schindling AG (Vodafone Group PLC)
• Inventors: Helmstadter, Gerald, Wokan, Andreas, Probst, Kurt
• Primary Examiner(s): Wolfe, Willis R.
• Application Number:
  US07/193,898
• Time in Patent Office: 438 Days
• Field of Search: 123/179 L, 123/198 D, 123/358, 123/359, 123/365, 123/479
• US Class Current: 123/365
• CPC Class Codes: F02D 11/107 Safety-related aspects
• CPC Class Codes: F02D 31/008 for idle speed control
• CPC Class Codes: F02D 41/222 relating to the failure of sensors or parameter detection devices
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

The safety monitoring of an electrical gas-pedal system having a desired-value transmitter (2), a controller unit (3), a controlling element (4) and safety contacts (8 and 9 respectively) associated with the desired-value transmitter and the controlling element includes the possibility of checking the safety contact (9) of the controlling element even if, as a result of an increased idling-speed-of-rotation control position or a mechanical limitation, the control position of the controlling element lies above the switch point of the safety contact. For this purpose, when the engine speed of rotation exceeds a given threshold value (ns) which results from the increased idling speed of rotation plus a safety margin, in the absence of a corresponding signal from the desired-value transmitter push operation is recognized by the controller unit (3), and the controlling element (3) is moved back to such an extent that the safety contact (9) must have switched. If a switching of the safety contact (9) does not take place then an error response is brought about.

Claims

1. In an electrical gas pedal system for an automotive vehicle, the vehicle having

a desired-value transmitter producing a desired value signal, an electronic controller unit responsive to the desired-value signal and to a speed of rotation measurement, a controlling element, a transmission unit and engine coupled to the transmission unit, displacement device, and a safety monitoring circuit;

and wherein

the controlling element is controlled by electric signals of the controller unit and is displaceable within a maximum possible desired setting range limited by first and second end positions, the displacement device is mechanically actuated by the controlling element and is displaceable in an actual-place range limited by a first and a second end position to control the engine output, there being means for increasing the engine idling speed of rotation;

wherein

the desired-value transmitter has a safety switch with contact which closes after a given path of displacement of the desired-value transmitter, the controlling-element has a safety switch with contact which opens after a given adjustment path of the controlling element, and the safety monitoring circuit monitors the manner of operation of the safety contacts to trigger an error reaction in the event of an error on the part of one of the safety contacts; and

wherein

in the presence of an increase in the idling speed of rotation, the controller unit is operative to provide a bridging over the desired-value-transmitter safety contact up to a speed-of-rotation threshold value and, at a speed of rotation above the threshold value, does away with the bridging; and

wherein

upon the speed exceeding the threshold value and in the absence of a correspondingly associated desired-value transmitter signal, the controller unit is operative to move the controlling element back into a position in which the controlling element safety contact is switched.

2. A system according to claim 1, wherein

the engine has an engine stop via injection-pump lever, and the controller unit is operative further to prevent a return of the controlling element for control of engine speeds of rotation which are only slightly above the idling speed of rotation but are below the threshold value, and permits only a brief return of the control element at higher speeds of rotation.