U.S. patent application number 09/745507 was filed with the patent office on 2002-10-24 for method and device for operating an internal combustion engine.
Invention is credited to Gras, Juergen.
Application Number | 20020155923 09/745507 |
Document ID | / |
Family ID | 7933761 |
Filed Date | 2002-10-24 |
United States Patent
Application |
20020155923 |
Kind Code |
A1 |
Gras, Juergen |
October 24, 2002 |
Method and device for operating an internal combustion engine
Abstract
A method and a device for operating an internal combustion
engine for a road vehicle having an automatic transmission, it
being detected if the road vehicle is rolling back while forward
gear is engaged, and the ignition angle of the internal combustion
engine being changed to increase the torque of the internal
combustion engine when back-rolling is detected while forward gear
is engaged.
Inventors: |
Gras, Juergen;
(Bietigheim-Bissingen, DE) |
Correspondence
Address: |
KENYON & KENYON
ONE BROADWAY
NEW YORK
NY
10004
US
|
Family ID: |
7933761 |
Appl. No.: |
09/745507 |
Filed: |
December 22, 2000 |
Current U.S.
Class: |
477/111 |
Current CPC
Class: |
F02D 31/003 20130101;
B60W 30/18118 20130101; F02D 37/02 20130101; F02D 41/0002 20130101;
F02P 5/04 20130101; Y02T 10/40 20130101; F02D 41/021 20130101; B60W
2510/1005 20130101 |
Class at
Publication: |
477/111 |
International
Class: |
B60K 041/04; F02P
005/15 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 22, 1999 |
DE |
199 61 943.3 |
Claims
1. A method for operating an internal combustion engine (10) for a
road vehicle having an automatic transmission, it being detected if
the road vehicle is rolling back while forward gear is engaged,
characterized in that the ignition angle of the internal combustion
engine (10) is changed to increase the torque (M) of the internal
combustion engine (10) when back-rolling is detected with forward
gear engaged.
2. The method as recited in claim 1, characterized in that more air
is metered into the internal combustion engine (10) when
back-rolling is detected with forward gear engaged.
3. The method as recited in claim 1 or 2, characterized in that
more air is metered into the internal combustion engine (10) when,
after changing the ignition angle of the internal combustion engine
(10) to increase the torque of the internal combustion engine (10),
back-rolling is detected with forward gear engaged.
4. The method as recited in claim 1, 2 or 3, characterized in that
a calculation is made of the increase in torque of the internal
combustion engine (10) necessary to prevent the road vehicle from
rolling backwards when forward gear is engaged.
5. The method as recited in claim 4, characterized in that a
calculation is made of the increase in torque of the internal
combustion engine (10) which is possible by changing the ignition
angle of the internal combustion engine (10).
6. The method as recited in one of the preceding claims,
characterized in that more air is metered into the internal
combustion engine (10) when the increase in torque (M) of the
internal combustion engine (10) necessary to prevent the road
vehicle from rolling backwards while forward gear is engaged is
greater than the increase in torque (M.sub.max) of the internal
combustion engine (10) possible by changing the ignition angle of
the internal combustion engine (10).
7. The method as recited in one of claims 2 through 6,
characterized in that the air is metered in with the aid of a
bypass adjuster (17).
8. The method as recited in one of claims 2 through 6,
characterized in that the air is metered in with the aid of an
electrically adjustable throttle device.
9. A device for operating an internal combustion engine (10) for a
road vehicle having an automatic transmission according to a method
as recited in one of the preceding claims, it being detected if the
road vehicle is rolling back while forward gear is engaged,
characterized in that the device for operating the internal
combustion engine (10) has an electronic control unit (20) for
changing the ignition angle of the internal combustion engine (10)
upon detecting that the road vehicle is rolling backwards while
forward gear is engaged, in such a way that the torque of the
internal combustion engine (10) is increased.
Description
[0001] The invention relates to a method and a device for operating
an internal combustion engine for a road vehicle having an
automatic transmission, it being detected if the road vehicle is
rolling back while forward gear is engaged.
[0002] Such a method and device, respectively, are known from the
German Patent 35 34 675 C2.
[0003] The object of the present invention is to further improve
the above-indicated method and device.
[0004] The objective is achieved according to the invention by a
method as recited in claim 1 and by a device as recited in claim 9.
In this context, for operating an internal combustion engine for a
road vehicle having an automatic transmission, it is detected
whether there is back-rolling while forward gear is engaged, and
upon detecting that the road vehicle is rolling back, the ignition
angle of the internal combustion engine is altered to increase the
engine torque. Thus, if back-rolling or the beginning of
back-rolling is detected with forward gear engaged, then the
ignition angle of the internal combustion engine is changed in such
a way that the torque of the internal combustion engine is
increased. In this manner, possible back-rolling of the road
vehicle is eliminated more quickly and effectively than with the
known method.
[0005] In an advantageous refinement of the invention, more air is
metered into the internal combustion engine when it is detected
that there is back-rolling with forward gear engaged. This
additional measure effectively prevents back-rolling, even when
there is a sharp incline.
[0006] One advantageous development of the invention provides for
metering more air into the internal combustion engine when, after
changing the ignition angle of the internal combustion to increase
the engine torque, back-rolling is detected when forward gear is
engaged.
[0007] In a further advantageous embodiment of the invention, a
calculation is made of the increase in torque of the internal
combustion engine necessary for preventing the road vehicle from
rolling back while forward gear is engaged.
[0008] In another advantageous invention refinement, the increase
in torque of the internal combustion engine which is possible by
changing the ignition angle of the internal combustion engine is
calculated.
[0009] A further advantageous development of the invention provides
for metering more air into the internal combustion engine when the
increase in torque of the internal combustion engine necessary for
preventing the road vehicle from rolling back when forward gear is
engaged is greater than the increase in internal-combustion-engine
torque which is possible by changing the ignition angle of the
engine.
[0010] According to another advantageous embodiment of the
invention, the air is metered in with the aid of a bypass adjuster
or by an electrically controllable throttle device (ETC)
[electronic throttle control].
[0011] Further advantages and particulars are described in the
following description of exemplary embodiments. In detail:
[0012] FIG. 1 shows a rough schematic representation of an internal
combustion-engine control system;
[0013] FIG. 2 shows a rough schematic representation of an
alternative internal-combustion-engine control system; and
[0014] FIG. 3 shows a flow chart for describing an exemplary
embodiment of the design approach according to the present
invention.
[0015] The exemplary embodiments in FIGS. 1 and 2 relate to an
internal-combustion-engine control system having a fuel-injection
installation and a charge adjustment. In FIGS. 1 and 2, reference
numeral 10 indicates an internal combustion engine, 11 indicates an
air-intake pipe, and an exhaust pipe is indicated by 12. Disposed
one behind the other in air-intake pipe 11, when viewed in the
direction of flow, is a measuring device 13 for the air throughput
in the intake pipe, a throttle valve 14 and a fuel injector 15.
Parallel to throttle valve 14 is a bypass channel 16, in which is
disposed a bypass adjuster 17 for changing the bypass
cross-section. As an alternative to bypass channel 16, in which a
bypass adjuster 17 is arranged for changing the bypass
cross-section, it is possible to provide an electrically
controllable throttle device (a so-called ETC), as shown in FIG. 2,
which is used to meter in the air. The electrically controllable
throttle device has a throttle valve 18, as well as an electric
servomotor 19 for adjusting throttle valve 18. Electric servomotor
19 is controlled by an electronic control unit, designated by
reference numeral 20, for controlling internal combustion engine
10. By suitable control using electronic control unit 20, the
electrically controllable throttle device replaces throttle valve
14 and bypass channel 16 in which bypass adjuster 17 is
arranged.
[0016] Electronic control unit 20 receives, inter alia, signals
with respect to speed n of internal combustion engine 10, load
Q.sub.L of internal combustion engine 10, throttle-valve position
DK and temperature u. Electronic control unit 20 also receives a
signal G concerning the transmission setting, as well as a value,
having an operational sign, for speed V.sub.R of at least one wheel
of the road vehicle.
[0017] A driving signal for electromagnetic fuel injector 15 is
formed in electronic control unit 20 as a function of speed n and
load Q.sub.L of internal combustion engine 10. While the throttle
valve is closed, electronic control unit 20, with the aid of an
idle-speed control, assures that the idling speed can be held to a
low value.
[0018] In addition, electronic control unit 20 evaluates the value,
having an operational sign, for speed V.sub.R of at least one wheel
of the road vehicle, and signal G concerning the transmission
setting, and thus ascertains an (unintentional) back-roll,
accompanied by engaged forward gear. If it is detected that there
is a back-roll when forward gear is engaged, electronic control
unit 20 changes the ignition angle of the internal combustion
engine in such a way that the engine torque is increased. If, in
spite of this measure, electronic control unit 20 detects that the
vehicle is rolling backward while forward gear is engaged, then it
drives bypass adjuster 17 in bypass channel 16 for throttle valve
14 in a manner that the bypass cross-section is enlarged (FIG. 1),
or it drives the electrically controllable throttle device in a
manner that the opening of throttle valve 18 is enlarged (FIG. 2),
to thus produce an increased torque in internal combustion engine
10, which in turn then prevents the vehicle from rolling backwards
at the incline. section of bypass adjuster 17 in FIG. 1 is
increased with the aid of block 36 and a subsequent speed query 37,
until subsequent speed query 37 ascertains the end of back-rolling,
and thus a speed equal to zero. This value of the corresponding
driving signal for bypass adjuster 17 is then retained in block 39,
further interventions still naturally being possible, however, to
prevent, for instance, load fluctuations because of switching an
air-conditioning compressor on or off. In an implementation
according to FIG. 2, blocks 36 and 39 must be adapted accordingly.
Thus, throttle valve 18 is opened further until speed query 37
ascertains the end of back-rolling, and thus a speed equal to zero.
The value of the corresponding driving signal for servomotor 19 is
then retained in block 39.
[0019] A further query 40 follows, to the effect that the
accelerator is not depressed (accelerator position 0) or as to
whether throttle valve 14 is closed. As long as this is the case,
the subroutine is run through continuously; otherwise there is a
return to the main program, according to the data in block 41.
[0020] Alternatively to the logic existing with respect to block
33, speed query 34 and torque query 35, provision can be made to
calculate the increase in torque of the internal combustion engine
necessary to prevent the road vehicle from rolling back with
forward gear engaged, and to increase the ignition angle
accordingly. If the increase in torque of the internal combustion
engine necessary to prevent the road vehicle from rolling back
while forward gear is engaged is greater than the increase in
torque of the internal combustion engine possible by changing the
ignition angle of the internal combustion engine, then the ignition
angle is adjusted in such a way that the torque of the internal
combustion engine assumes its maximum value attainable by changing
only the ignition angle of the internal combustion engine. In
addition, more air is metered into the internal combustion engine,
i.e., the loop composed of block 36 and the speed query is run
through.
* * * * *