Title: Prevention of slippage in belt-type continuously variable transmission
Abstract: A vehicle engine (70) is connected with a belt-type continuously variable transmission (1) via a clutch (32). The transmission (1) transmits torque via a belt (43) between a pair of pulleys (41, 42), and varies the transmission torque according to a supply of oil pressure. The clutch (32) engages by means of oil pressure supplied as a shift lever is changed over from a neutral range to a drive range. An oil pressure supplying device (10, 44, 45, 46) supplies the oil pressure required to transmit torque between the belt (43) and the pulleys (41, 42), and the oil pressure for engaging the clutch (32). Slippage between the belt (43) and the pulleys (41, 42) is prevented during engagement of the clutch (32) by restricting the output torque of the engine (70) over a predetermined period of time.
Patent Number: 6,896,639 Issued on 05/24/2005 to Kang, et al.
| Inventors:
|
Kang; Jihoon (Shizuoka, JP);
Kawamura; Yasutaka (Shizuoka, JP);
Ochiai; Tatsuo (Shizuoka, JP);
Okahara; Hirofumi (Shizuoka, JP)
|
| Assignee:
|
Jatco LTD (Fuji, JP)
|
| Appl. No.:
|
651243 |
| Filed:
|
August 29, 2003 |
Foreign Application Priority Data
| Sep 02, 2002[JP] | 2002-256463 |
| Current U.S. Class: |
477/44; 477/107 |
| Intern'l Class: |
B60K 041/12; B60K041/04 |
| Field of Search: |
477/44- 45,107,109,111
475/208-209
|
References Cited [Referenced By]
U.S. Patent Documents
| 5042324 | Aug., 1991 | Suzuki.
| |
| 5820514 | Oct., 1998 | Adachi.
| |
| 6168546 | Jan., 2001 | Loffler et al.
| |
| 6454675 | Sep., 2002 | Asayama et al.
| |
| 6684142 | Jan., 2004 | Janssen et al.
| |
| 2001/0023216 | Sep., 2001 | Bolz et al.
| |
Primary Examiner: Pang; Roger
Attorney, Agent or Firm: Foley & Lardner LLP
Claims
1. A vehicle drive train comprising:
an engine;
a continuously variable transmission comprising a pair of pulleys that are mutually
connected via a belt, wherein the continuously variable transmission varies torque
transmitted between the pulleys via the belt according to a supplied oil pressure;
a clutch which connects the engine to one of the pair of pulleys by engaging
in accordance with a supplied oil pressure, wherein the oil pressure is supplied
to the clutch and continuously variable transmission from an identical oil pressure
source;
a drive wheel connected to the other of the pair of pulleys; and
an engine output regulating mechanism which reduces an output torque of the engine
when the clutch is engaged,
wherein the clutch is engaged by changing over a shift lever of the vehicle from
a neutral range to a drive range, and wherein the engine output regulating mechanism
further comprises a sensor which detects a change-over of the shift lever from
a neutral range to a drive range, a sensor which detects a travel speed of the
vehicle, and a programmable controller programmed to reduce the output torque of
the engine when the shift lever is shifted from the neutral range to the drive
range while the vehicle is traveling at or above a predetermined speed.
2. The vehicle drive train device as defined in claim 1, wherein the engine output
regulating mechanism further comprises a sensor which detects a speed ratio of
the continuously variable transmission and a sensor which detects an oil pressure
supplied to the continuously variable transmission, and the controller is further
programmed to calculate a maximum transmitted torque that can be transmitted between
the pulleys via the belt on the basis of the speed ratio and the oil pressure supplied
to the continuously variable transmission, and to reduce the output torque of the
engine so as not to exceed the maximum transmitted torque.
3. The vehicle drive train device as defined in claim 1, wherein the controller
is further programmed to reduce the output torque of the engine within a predetermined
period of time when the shift lever is changed over from the neutral range to the
drive range while the vehicle is traveling at or above the predetermined speed.
4. The vehicle drive train device as defined in claim 1, wherein the engine output
regulating mechanism further comprises a throttle for regulating an intake airflow
amount of the engine, and the controller is further programmed to restrict the
output torque of the engine by reducing an opening of the throttle.
5. The vehicle drive train device as defined in claim 1, wherein the controller
is further programmed to reduce the oil pressure supplied to the continuously variable
transmission within a predetermined period of time when the shift lever is shifted
from the neutral range to the drive range while the vehicle is traveling at or
above the predetermined speed.
Description
FIELD OF THE INVENTION
This invention relates to preventing slippage in the belt of a belt-type continuously
variable transmission for use in a vehicle.
BACKGROUND OF THE INVENTION
U.S. Pat. No. 5,820,514 discloses a belt-type continuously variable transmission
(hereinafter referred to as belt CVT) for use in a vehicle.
The belt CVT comprises a primary pulley for inputting the drive force of an engine,
a secondary pulley for outputting the drive force to a drive wheel, and a V-belt
that is wrapped around the primary pulley and secondary pulley. In the primary
pulley and secondary pulley, pulley grooves for accepting the belt are each varied
in width by oil pressure. Changes in the width of the pulley grooves change the
contact radius between the V-belt and the pulley, which results in changing the
rotation speed ratio of the primary pulley and the secondary pulley, or in other
words the speed ratio of the transmission.
The output rotation of the engine is transmitted to the primary pulley via a
torque converter and a forward/reverse change-over mechanism.
The forward/reverse change-over mechanism comprises a forward clutch that is
engaged during forward travel of the vehicle, or in other words when the driver
places a shift lever in a drive range (D), and a reverse clutch that is engaged
during reverse travel, or in other words when the driver places the shift lever
in the reverse range (R). When the shift lever is in the neutral range (N), both
of these clutches are released, and the output rotation of the engine is not transmitted
to the primary pulley. These clutches are engaged by means of oil pressure, and
the clutches are released from an engaged state by the release of oil pressure
into a drain.
SUMMARY OF THE INVENTION
In this type of belt CVT, when the shift lever is moved from the drive range
(D)
to the neutral range (N) and then back to the drive range (D) during vehicle travel,
the oil pressure engaging the forward clutch is released all at once into the drain
and is thus reduced, and oil pressure is subsequently re-supplied to the forward
clutch for the engagement thereof.
Meanwhile, the primary pulley and secondary pulley of the belt CVT require
a constant oil pressure in order to prevent slippage in the V-belt while maintaining
the present groove width, regardless of whether a change in speed ratio has been directed.
Because oil pressure is usually supplied by the same oil pressure supply
unit, the oil pressure supplied to the belt CVT temporarily decreases due to the
effect of supplying oil pressure to the forward clutch when an operation is performed
whereby the shift lever is moved from the drive range (D) to the neutral range
(N), and then back to the drive range (D) during vehicle travel. As a result, the
power by which the pulley holds the V-belt can be insufficient for the rotation
torque of the engine that is input to the primary pulley during the change-over
from the neutral range (N) to the drive range (D), and slippage can occur between
the pulley and the V-belt. V-belt slippage is especially likely to occur when the
accelerator pedal is depressed following re-selection of the drive range (D) since
the input torque to the primary pulley suddenly increases. This type of slippage
in a V-belt consisting of a metal member contributes to impaired durability of
the V-belt.
It is therefore an object of this invention to prevent slippage in a belt-type
continuously variable transmission accompanying an operation of a shift lever during
vehicle travel.
In order to achieve the above object, this invention provides a vehicle drive
train comprising an engine, a continuously variable transmission comprising a pair
of pulleys that are mutually connected via a belt wherein the continuously variable
transmission varies torque transmitted between the pulleys via the belt according
to a supplied oil pressure, a clutch which connects the engine to one of the pair
of pulleys by engaging in accordance with a supplied oil pressure wherein the oil
pressure is supplied to the clutch and continuously variable transmission from
an identical oil pressure source, a drive wheel connected to the other of the pair
of pulleys, and an engine output regulating mechanism which reduces an output torque
of the engine when the clutch is engaged.
The details as well as other features and advantages of this invention are set
forth in the remainder of the specification and are shown in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a drive train control device for a vehicle
according to this invention.
FIGS. 2A and 2B are block diagrams depicting the configuration of a controller
according to this invention.
FIG. 3 is a flow chart describing an engine output torque regulation routine
executed by the controller.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 of the drawings, a belt CVT
1 for use in a vehicle
comprises a primary pulley
41, a secondary pulley
42, and a V-belt
43 wrapped around the pulleys
41 and
42.
The primary pulley
41 comprises a fixed conical plate
41a and
a movable conical plate
41b disposed facing each other. The V-belt
43 catches in a pulley groove that is V-shaped in cross-section and is formed
between the fixed conical plate
41a and the movable conical plate
41b. The movable conical plate
41b moves in response
to a primary pressure supplied via a primary pressure regulating unit
44
to vary the width of the pulley groove and the contact radius between the V-belt
43 and the primary pulley
41. The movable conical plate
41b
is fixed to an input shaft
41c. The output rotation of an engine
70 mounted in the vehicle is input to the input shaft
41c via
a torque converter
20 and a forward/reverse change-over mechanism
30.
The secondary pulley
42 comprises a movable conical plate
42a
and a fixed conical plate
42b disposed facing each other. The
V-belt
43 catches in a pulley groove that is V-shaped in cross-section and
is formed between the movable conical plate
42a and the fixed conical
plate
42b. The movable conical plate
42a moves in response
to a secondary pressure supplied via a secondary pressure regulating unit
45
to vary the width of the pulley groove and the contact radius between the V-belt
43 and the secondary pulley
42. The rotation of the fixed conical
plate
42b is transmitted to a drive wheel
80 of the vehicle.
The pressure-receiving surface area of the movable conical plate
41b
and movable conical plate
42a are set to be substantially equal.
The torque converter
20 is a publicly known mechanism for transmitting
the rotation of the engine
70 by means of the flow of oil between a pump
impeller and a turbine liner. The torque converter
20 comprises a lockup
device for causing the pump impeller to rotate in integrated fashion with the turbine liner.
The forward/reverse change-over mechanism
30 comprises a planetary gear
set
31, a forward clutch
32, and a reverse clutch
33. The
planetary gear set
31 comprises an external sun gear
31a,
and an internal ring gear
31d disposed on the outside thereof. A
plurality of pinions
31b that mesh with the outside perimeter of
the sun gear
31a and the inside perimeter of the ring gear
31d
and a carrier
31c for supporting the pinions
31b are
furthermore comprised therein. The sun gear
31a is connected to an
output shaft of the torque converter
20, and the carriers
31c
are connected to the input shaft
41c of the primary pulley
41.
The forward clutch
32 connects the carrier
31c with the
sun gear
31a according to oil pressure supplied to a clutch piston
chamber
32a from a clutch pressure regulating unit
35. As
a result, the output rotation of the torque converter
20 is transmitted
as is to the input shaft
41c of the primary pulley
41 via
the sun gear
31a and carrier
31c.
The reverse clutch
33 locks the rotation of the ring gear
31d
according to the oil pressure supplied to a clutch piston chamber
33a
from the clutch pressure regulating unit
35. As a result, the sun gear
31a and carrier
31c rotate in opposite directions,
and the output rotation of the torque converter
20 is transmitted to the
input shaft
41c of the primary pulley
41 in reverse.
The forward clutch
32 and reverse clutch
33 are engaged exclusively.
Specifically, the reverse clutch
33 is invariably released when the forward
clutch
32 is engaged, and the forward clutch
32 is invariably released
when the reverse clutch
33 is engaged. In a state in which the forward clutch
32 and reverse clutch
33 are both released, the sun gear
31a
and carrier
31c rotate relative to each other in arbitrary fashion.
Oil pressure is supplied to the primary pressure regulating unit
44, secondary
pressure regulating unit
45, and clutch pressure regulating unit
35
from an oil pressure pump
10 driven by the engine
70. The discharge
pressure of the oil pressure pump
10 is regulated to a predetermined line
pressure by means of a line pressure regulating unit
46, and is distributed
to the primary pressure regulating unit
44, secondary pressure regulating
unit
45, and clutch pressure regulating unit
35. The primary pressure
regulating unit
44 furthermore regulates the line pressure to a predetermined
primary pressure to operate the movable conical plate
41b of the
primary pulley
41. The secondary pressure regulating unit
45 furthermore
regulates the line pressure to a predetermined secondary pressure to operate the
movable conical plate
42a of the secondary pulley
42. The
line pressure of the clutch pressure regulating unit
35 is regulated to
a predetermined clutch pressure, and is selectively supplied to the forward clutch
32 and reverse clutch
33.
The primary pressure regulating unit
44, secondary pressure regulating
unit
45, and line pressure regulating unit
46 respectively regulate
the primary pressure, secondary pressure, and line pressure according to command
signals from a controller
60.
The clutch pressure regulating unit
35 supplies the oil pressure used
for engaging a particular clutch according to the command signal from the controller
60.
The controller
60 is composed of a microcomputer that comprises a central
processing unit (CPU), read-only memory (ROM), random access memory (RAM), and
an input/output interface (I/O interface). The controller may also be composed
of a plurality of microcomputers.
The controller
60 controls the primary pressure, secondary pressure, and
line pressure, and engages and releases the forward clutch
32 and reverse
clutch
33. The controller
60 also controls the output torque of the
engine
70 by outputting an engine control signal to an electronic throttle
61 provided in the engine
70.
Detected data from a rotation speed sensor
47 for detecting the rotation
speed of the engine
70, a rotation speed sensor
51 for detecting
the rotation speed of the primary pulley
41, a rotation speed sensor
52
for detecting the rotation speed of the secondary pulley
42, a pressure
sensor
53 for detecting the primary pressure, a pressure sensor
54
for detecting the secondary pressure, an inhibitor switch
56 for detecting
the selected position of the shift lever provided to the vehicle, and an accelerator
pedal depression sensor
57 for detecting the amount of depression of the
accelerator pedal provided in the vehicle are input as signals to the controller
60 to serve as parameters for controlling these actions. The shift lever
is provided with a drive range (D) used for forward travel, a reverse range (R)
used for reverse travel, and a neutral range (N) in which the rotation torque of
the engine
70 is not transmitted to the drive wheel.
Because the secondary pulley
42 is connected with drive wheel
80,
the rotation speed of the secondary pulley
42 detected by the rotation speed
sensor
52 is utilized as a parameter for indicating the vehicle speed.
The controller
60 performs publicly known control relating to the operation
of the forward clutch
32 and reverse clutch
33 of the forward/reverse
change-over mechanism
30 according to the range selection of the shift lever,
and relating to the speed ratio of the publicly known belt CVT
1, which
is controlled by the primary pressure and secondary pressure. Furthermore, the
controller
60 limits the output torque of the engine
70 so that no
slippage occurs in the V-belt
43 when the shift lever is operated from the
drive range (D) to the neutral range (N) and from the neutral range (N) to the
drive range (D) within a short amount of time during vehicle travel, as previously described.
Referring to FIGS. 2A and 2B, the functioning of the controller
60
for limiting the output torque will now be described.
The controller
60 comprises a transmission control unit
61 and
an engine control unit
62.
The transmission control unit
61 is composed of a torque-limiting condition
determining block
61a, an oil pressure controlling block
61b,
a torque limiting initiation/termination determining block
61c, a
torque capacity calculating block
61d, an input torque calculating
block
61e, a torque limit determining block
61f, a
torque limit value calculating block
61g, and a torque limit value
output block
61h.
The engine control unit
62 is composed of an engine torque calculating
block
62a, a torque-down amount calculating block
62b,
and an electronic throttle opening regulating block
62c.
The units and blocks depicted in the drawings are hypothetical units/blocks depicting
functions of the controller
60, and do not exist physically.
The torque-limiting condition determining block
61a determines
whether torque-limiting conditions are established based on the selected range
input from the inhibitor switch
56 and on the rotation speed of the secondary
pulley
42 input from the rotation speed sensor
52. Torque limiting
conditions are established when the selected range of the shift lever shifts from
the neutral range to the drive range at a vehicle speed that is at or above a set
vehicle speed. The set vehicle speed is set in this case at ten kilometers per
hour. The torque-limiting condition is not satisfied when the vehicle speed is
less than ten kilometers per hour, because the vehicle start-up performance will
be adversely affected, if the output torque of the engine
70 is limited
to a vehicle speed less than ten kilometers per hour.
The oil pressure controlling block
61b limits the line pressure
and secondary pressure over a predetermined time period to pressures that the oil
pressure pump
10 is capable of generating. The line pressure is limited
in order to maintain the engaging pressure of the forward clutch
32, and
the secondary pressure is limited so as to prevent the speed ratio of the belt
CVT
1 from increasing, or in other words to prevent the output rotation
of the belt CVT
1 from decreasing. Limiting the line pressure results in
limiting the primary pressure. As a result, the primary pressure is maintained
at a low pressure over a predetermined time period after the selected range of
the shift lever is changed over from the neutral range to the drive range, as depicted
in the drawing of the torque limit determining block
61f.
The torque limiting initiation/termination determining block
61c sets
a torque limit flag to unity when torque limiting conditions are established based
on the determination results of the torque limiting-condition determining block
61a, and resets the torque limit flag to zero when torque limiting
conditions are not established. The initial value of the torque limit flag is zero.
The torque capacity calculating block
61d calculates the speed
ratio of the belt CVT
1 from the rotation speed of the primary pulley
41
and rotation speed of the secondary pulley
42. Furthermore, the maximum
torque that would not cause the belt
43 to slip against the primary pulley
41 and secondary pulley
42 is calculated based on the speed ratio
and the secondary pressure detected by the pressure sensor
54. This value
is labeled as the torque capacity Tc.
The input torque calculating block
61e sets the actual engine torque
Te input from the engine control unit
62 as the input torque Ti of the belt
CVT
1.
The torque limit determining block
61f compares the input torque
Ti and torque capacity Tc of the belt CVT
1, and determines that torque
limiting is necessary for the input torque Ti when the torque capacity Tc falls
below the input torque Ti, as shown by the shaded area in the figure.
The torque limit value calculating block
61g limits the input torque
Ti to the torque capacity Tc when it is necessary to limit the input torque.
The torque limit value output block
61h outputs a torque limit
requirement value that is in accordance with the torque limit flag to the torque-down
amount calculating block
62b. When the torque limit flag is at zero,
a maximum value for the torque limit requirement value is output to the torque-down
amount calculating block
62b as the torque limit requirement value.
Herein the maximum value denotes that no torque limitation is required. When the
torque limit flag is at unity, the input torque Ti calculated by the torque limit
value calculating block
61g is output as the torque limit requirement
value to the torque-down amount calculating block
62b.
The engine torque calculating block
62a of the engine control unit
62 calculates the throttle valve opening TVO of the engine
70 from
the amount of depression of the accelerator pedal, and calculates the output torque
of the engine
70 from the throttle valve opening TVO, fuel injection amount
of the engine
70, and rotation speed of the engine
70, with reference
to a map having characteristics such as those shown in the figure. If the controller
60 also controls the fuel injection amount of the engine
70, the
controller
60 is capable of obtaining the fuel injection amount from data
that are stored therein.
The torque-down amount calculating block
62b calculates a torque-down
amount on the basis of the torque limit requirement value that is input from the
torque limit value output block
61h and the output torque of the
engine
70 calculated by the engine torque calculating block
62a.
The electronic throttle valve opening regulating block
62c narrows
the valve opening of the electronic throttle
61 according to the torque-down amount.
Next, referring to FIG. 3, a routine executed according to the above configuration
whereby the controller
60 prevents belt slippage in the belt CVT
1
will be described. This routine is executed at intervals of ten milliseconds during
operation of the engine
70.
First, in a step S
1, the controller
60 determines whether the
vehicle speed is at or above the previously described set vehicle speed of ten
kilometers per hour on the basis of the rotation speed of the secondary pulley
42 detected by the rotation speed sensor
52. When the vehicle speed
is under ten kilometers per hour, the controller
60 determines that limiting
of the output torque of the engine
70 will not be performed in a step S
8,
and the routine is terminated.
When the vehicle speed is at or above ten kilometers per hour, the controller
60 determines in a step S
2 whether the torque limit flag is at unity.
When the torque limit flag is not at unity, the controller
60 performs the
processing of a step S
3.
In the step S
3, the controller
60 determines whether the shift
lever
has been changed over from the neutral range (N) to the drive range (D). This determination
is performed by comparing the input signal from the inhibitor switch
56
with the previous input signal at fixed time intervals. If the shift lever has
not been changed over from the neutral range (N) to the drive range (D), the controller
60 determines that limiting of the output torque of the engine
70
will not be performed in the step S
8, and the routine is terminated.
When the shift lever has been changed over from the neutral range (N) to the
drive range (D), the controller
60 sets the torque limit flag to unity in
a step S
4.
Next, in a step S
5, the controller
60 limits the line pressure
and secondary pressure to pressures that the oil pressure pump
10 is capable
of generating.
The controller
60 furthermore calculates the torque-down amount in a subsequent
step S
6.
In a subsequent step S
7, the controller
60 limits the output torque
of the engine
70 on the basis of the torque-down amount. The controller
60 terminates the routine after the process in the step S
7.
On the other hand, in the step S
2, when the torque limit flag is at unity,
the controller
60 determines whether a predetermined period of time has
elapsed since the torque limit flag was set to unity in a step S
9. If the
predetermined period of time has not elapsed, the controller
60 executes
the processing beginning in the step S
5.
When the predetermined period of time has elapsed, the controller
60
stops limiting the output torque of the engine
70 in a step S
10,
the torque limit flag is set to zero, and the routine is terminated. The predetermined
period of time corresponds to the time required for torque limiting to become unnecessary
after changing over from the neutral range (N) to the drive range (D), and is determined
experientially in advance.
By executing this routine, the output torque of the engine
70 is limited
over the predetermined period of time when the shift lever is changed over from
the neutral range (N) to the drive range (D) while the vehicle is traveling at
or above the predetermined vehicle speed.
In the routine described above, the steps S
1 through S
3 and the
step S
9 correspond to the functioning of the torque-limiting condition determining
block
61a, the step S
4 corresponds to the functioning of the
torque limiting initiation/termination determining block
61c, the
step S
5 corresponds to the functioning of the oil pressure controlling block
61b, and the step S
6 corresponds to the functioning of the
torque capacity calculating block
61d, input torque calculating block
61e, torque limit determining block
61f, torque limit
value calculating block
61g, engine torque calculating block
62a,
and torque-down amount calculating block
62b. The step S
7
corresponds to the functioning of the throttle valve opening regulating block
62c,
and the steps S
8 and S
10 correspond to the functioning of the torque
limit value output block
61h.
During changing over from the neutral range (N) to the drive range (D), the
oil pressure which acts upon the primary pulley
41 and secondary pulley
42 is reduced in order to maintain the engaging pressure of the forward
clutch
32. However, the primary pulley
41 and secondary pulley
42
are able even in this case to maintain the necessary holding force to prevent the
input torque Ti input to the belt CVT
1 from the engine
70 from exceeding
the torque capacity Tc, and the belt
43 from slipping. Also, when the accelerator
pedal is depressed during changing over from the neutral range (N) to the drive
range (D), the belt
43 does not slip because the torque Ti that is input
to the belt CVT
1 from the engine
70 is controlled so as not to exceed
the torque capacity Tc.
Also, because the output torque of the engine
70 is limited only for
the predetermined period of time based on the torque capacity that is calculated
based on the actual speed ratio and primary pressure, limiting of the output torque
of the engine can be kept to the required minimum.
The contents of Tokugan 2002-256463, with a filing date of Sep. 2, 2002 in Japan,
are hereby incorporated by reference.
Although the invention has been described above by reference to certain
embodiments of the invention, the invention is not limited to the embodiments described
above. Modifications and variations of the embodiments described above will occur
to those skilled in the art, in light of the above teachings.
For example, the predetermined vehicle speed is set to ten kilometers per hour
in this embodiment, but can be changed to any speed according to the specifications
of the engine or belt CVT to which the invention is applied.
In the embodiment thus described, changing over of the shift lever from the neutral
range to the drive range is detected by the inhibitor switch
56, and the
vehicle speed is detected by the rotation speed sensor
54 in order to determine
whether the torque limiting condition is established. The speed ratio calculated
from the speed detected by the rotation speed sensors
53 and
54,
and the secondary pressure detected by the pressure sensor
54 are used to
calculate the torque capacity of the belt CVT
1. The engine rotation speed
is detected by the rotation speed sensor
47, the valve opening of the electronic
throttle
61 is detected from the accelerator pedal depression amount sensor
57, and the fuel injection amount of the engine
70 is obtained from
data stored within the controller
60 in order to calculate the output torque
of the engine
70. The parameters for these controls can, however, be detected
or calculated by various other means. This invention can be applied to any vehicle
drive train device that uses the above parameters to control the claimed engine
output torque, independent of the method used to acquire the parameters.
The embodiments of this invention in which an exclusive property or privilege
is claimed are defined as follows:
*
