Start-from-stop engine torque limiting

Details Start-from-stop engine torque limiting Start-from-stop engine torque limiting

1998-06-19

2001-02-06

Louis-Jacques, Jacques H. (Department: 3661)

Data processing: vehicles, navigation, and relative location

Vehicle control, guidance, operation, or indication

Transmission control

C701S053000, C701S054000, C701S061000, C701S084000, C477S115000

Reexamination Certificate

active

06185494

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a fully or partially automated vehicular transmission system having an engine controller for controlling engine output torque (i.e., engine flywheel torque) in response to command signals and, in particular, to an automated vehicular transmission system which, if the vehicle transmission is in a relatively high ratio at start-from-stop conditions, limits engine output torque to prevent or limit damage to vehicle power components.
2. Description of the Prior Art
Compound manually shifted mechanical transmissions of the range, splitter and/or combined range/splitter type are in wide use in heavy-duty vehicles and are well known in the prior art, as may be seen by reference to U.S. Pat. Nos. 4,754,665; 5,272,929; 5,370,013 and 5,390,561, 5,546,823; 5,609,062 and 5,642,643, the disclosures of which are incorporated herein by reference. Typically, such transmissions include a main section shifted directly or remotely by a manual shift lever and one or more auxiliary sections connected in series therewith. The auxiliary sections most often were shifted by a slave actuator, usually pneumatically, hydraulically, mechanically and/or electrically operated, in response to manual operation of one or more master switches. Shift controls for such systems by be seen by reference to U.S. Pat. Nos. 4,455,883; 4,550,627; 4,899,607; 4,920,815; 4,974,468; 5,000,060; 5,272,931; 5,281,902; 5,222,404 and 5,350,561, the disclosures of which are incorporated herein by reference.
Fully or partially automated transmission systems wherein a microprocessor-based electronic control unit (ECU) receives input signals indicative of various system operating conditions and processes same according to logic rules to issue command output signals to one or more system actuators are known in the prior art, as may be seen by reference to U.S. Pat. Nos. 4,361,060; 4,593,580; 4,595,986; 4,850,236; 5,435,212; 5,582,069; 5,582,558; 5,620,392; 5,651,292 and 5,679,096; 5,682,790; the disclosures of which are incorporated herein by reference.
Prior art vehicular powertrains having mechanical transmissions where subject to undue wear and/or damage if the driver attempts to launch the vehicle while engaged in a high ratio (i.e., low numerical ratio of input shaft to output shaft speed). While launching the vehicle when engaged in a high ratio can be accomplished by applying high throttle to increase engine speed and output torque while possibly slipping the master clutch, excessive wear and/or damage to the powertrain components could be expected.
SUMMARY OF THE INVENTION
A preferred embodiment of the present invention involves a computer-assisted mechanical compound transmission system wherein the main section is shifted by a manually controlled shift lever and the engine is fueled and/or the auxiliary sections are shifted by actuators at least partially controlled by an ECU to enhance shifting. The ECU uses sensed and/or calculated inputs indicative of system operating parameters, such as operation of a splitter switch and/or a range switch, position and/or rate of change of position of the shift lever, engaged gear ratio, engine speed, output shaft speed, clutch condition and/or throttle pedal position, to assist shifting by controlling engine fueling and/or operation of the range and/or splitter shift actuators.
In accordance with the present invention, the drawbacks of the prior art are minimized or overcome by the provision of a control system/method for a fully or partially automated vehicular transmission system which will sense operating conditions indicative of attempts to launch a vehicle while engaged in a relatively high ratio and, upon sensing such conditions, will cause engine output torque to be limited. This will prevent or minimize excessive wear and/or damage to the vehicle powertrain, will inform the operator that an inappropriate ratio for starting is engaged, and will discourage attempts by the driver to launch the vehicle under such conditions.
Accordingly, it is an object of the present invention to provide ECU assistance for enhanced shifting of a mechanical compound transmission having a main section shifted by a manually operated shift lever.
A further object is to provide a fully or partially automated vehicular mechanical transmission system in which engine output torque is limited at start-from-stop conditions if the transmission is engaged in a non-start ratio to prevent excessive wear and/or damage to the vehicle powertrain.
These and other objects and advantages of the present invention will become apparent from a reading of the following description of the preferred embodiment taken in connection with the attached drawings.


REFERENCES:
patent: 4754665 (1988-07-01), Vandervoort
patent: 4920815 (1990-05-01), Reynolds
patent: 4974468 (1990-12-01), Reynolds et al.
patent: 5000060 (1991-03-01), Reynolds et al.
patent: 5222404 (1993-06-01), Stine
patent: 5370013 (1994-12-01), Reynolds et al.
patent: 5390561 (1995-02-01), Stine
patent: 5582558 (1996-12-01), Palmeri et al.
patent: 5651292 (1997-07-01), Genise
patent: 5673592 (1997-10-01), Huggins et al.
patent: 5797110 (1998-08-01), Braun et al.
patent: 5894758 (1999-04-01), Walker
patent: 5904635 (1999-05-01), Genise et al.

Affiliated with

Also associated with

Rating

Start-from-stop engine torque limiting does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Start-from-stop engine torque limiting, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Start-from-stop engine torque limiting will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2603352