Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Transmission control
Reexamination Certificate
2001-09-28
2003-10-07
Cuchlinski, Jr., William A. (Department: 3661)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Transmission control
C701S058000, C477S078000
Reexamination Certificate
active
06631318
ABSTRACT:
This application is based on and claims priority under 35 U.S.C. §119 with respect to Japanese Patent Application 2000-303533, filed on Oct. 3, 2000, the entire content of which is incorporated herein by reference.
1. Field of the Invention
This invention generally relates to a control device which is applied in a synchromesh-type transmission for a vehicle. More particularly, this present invention pertains to a control device which is applied in a synchromesh-type transmission provided with a sleeve activated by a shift actuator in response to a shift operation. This invention further relates to a control device which controls operation of a shift actuator.
2. Background of the Invention
Vehicles such as passenger cars, buses and the like are generally driven by a driving power source such as a gasoline engine or an electric motor. The vehicle is provided with a transmission for producing a preferable vehicle driving condition in response to a vehicle running road condition. The transmission is for selecting gears, for meshing the selected gears with each other, and for changing the gears to be selected, to generate a desired torque or speed. As is well known, transmission types include a manual transmission (MT) and an automatic transmission (AT) in which a speed-change gear and a timing of speed-change are automatically selected.
As shown in
FIG. 7
, a known manual transmission (MT) is mainly formed as an input shaft
51
, a plurality of counter gears
52
, an output shaft
53
, a plurality of idle gears
61
, and a synchromesh mechanism
55
including a sleeve
56
. The input shaft
51
is supplied with driving force from the driving power source such as the gasoline engine. The plurality of counter gears
52
, are mounted on the input shaft
51
. The output shaft
53
outputs driving force to vehicle wheels (not shown) via a propeller shaft (not shown). The plurality of idle gears
61
are idly mounted on the output shaft
53
and always meshes with the counter gears
52
, respectively.
According to the vehicle provided with the known manual transmission, a predetermined speed-change gear is selected based on a manual shift operation by a driver. As shown in
FIG. 8
, upon the manual shift operation of a shift lever (not shown) by the driver, a shift fork shaft
67
(shown in
FIG. 8
) is moved by a shift operating force transmitted from the shift lever via a cable. Further, corresponding to the movement of the shift fork shaft
67
, the sleeve
56
is moved, wherein one of the idle gears
61
meshes with the output shaft
53
as a unit.
Somewhat recent developments have led to an automatic manual transmissions which are structurally based on the manual transmission (MT). As shown in
FIG. 8
, the automatic manual transmission performs the shift operation by a shift actuator
65
which is made of, for example, a hydraulic pressure motor or a hydraulic pressure cylinder. Therefore, the automatic manual transmission effectively relieves a manual operating load from the diver. The shift lever (not shown) is operated to transmit the driver's intention of speed-change and a timing of speed-change to an electronic control unit ECU
66
. The ECU
66
controls the timing and the amount to activate the shift actuator
65
.
The output from the shift actuator
65
is transmitted to the shift fork shaft
67
via a driving portion
65
a
(an output shaft of the shift actuator
65
) and a shift fork shaft operating device
68
(formed as an inner lever, an interlock plate, and a shift head). Immediately after the shift actuator
65
is activated, the shift fork shaft
67
is axially moved via the shift fork shaft operating device
68
. The sleeve
56
is integrally moved with the shift fork shaft
67
by an engagement between a projecting portion
67
a
of the shift fork shaft
67
and an engaging groove
56
a
defined in the sleeve
56
,
According to the known aforementioned automatic manual transmission, when the shift fork shaft
67
and the sleeve
56
are moved by the output from the shift actuator
65
via the shift fork shaft operating device
68
upon a synchronizing operation being performed, it is very important to determine the amount of driving force the shift actuator
65
applied to the sleeve
56
. More specifically, as shown in
FIG. 7
, the sleeve
56
is meshed with splines defined in a synchronizer hub
57
. The synchronizer hub
57
is rotated integrally with the output shaft
53
. When the driving force is applied to the sleeve
56
, a synchronizer key
58
is engaged with the sleeve
56
and moved therewith. An edge surface of the synchronizer key
58
pushes a synchronizer ring
59
against a cone portion of the idle gear
61
. Accordingly, the rotation of the idle gear
61
is gradually synchronized with the rotation of the sleeve
56
.
According to further movement of the sleeve
56
, the sleeve
56
is disengaged from the synchronizer key
58
and directly pushes the synchronizer ring
59
. The rotational speed of the idle gear
61
becomes equal to the rotational speed of the sleeve
56
due to frictional engagement between the synchronizer ring
59
and the idle gear
61
, i.e. the idle gear
61
is synchronized with the sleeve
56
. Hereinafter, the synchronizer ring
59
is rotated independently and does not hinder the sleeve
56
from moving. Therefore, the sleeve
56
passes through the synchronizer ring
59
and is engaged with the idle gear
61
, wherein the shift operation is completed.
If the driving force transmitted from the shift fork shaft
67
to the sleeve
56
is far larger than a desired amount, the synchronizer ring
59
and/or an inclined surface of the cone portion of the idle gear
61
may be damaged due to excess friction, thereby deteriorating durability of the idle gear. On the other hand, if the driving force transmitted from the shift fork shaft
67
to the sleeve
56
is far smaller than the desired amount, more time is required to perform the synchronizing operation between the sleeve
56
and the idle gear
61
. Furthermore, a reliable synchronizing operation may not occur. To overcome the aforementioned drawbacks, the amount of the driving force applied to the sleeve
56
via the shift fork shaft
67
has to be effectively controlled by the shift actuator
65
, so that the synchromesh mechanism
55
may operate with higher durability and with a shorter synchronizing time.
In view of the above, according to the known automatic manual transmission, a load detecting sensor
63
is mounted on the sleeve
56
as shown in FIG.
8
. The load detecting sensor
63
detects the driving force applied to the sleeve
56
. The detected value by the load detecting sensor
63
is transmitted to the ECU
66
, so that the driving force from the shift actuator
65
is controlled based on the detected value. However, extra time may be required for installing the sensor
63
and an extra load may be placed on the sleeve
56
. Further, manufacturing cost will increase for mounting the load detecting sensor
63
on the sleeve
56
.
According to the known automatic manual transmission, an output indicating value which is input to the shift actuator
65
is detected. If the shift actuator
65
is made of a hydraulic pressure motor, the output indicating value is an electric current value supplied to a coil. If the shift actuator
65
is made of a hydraulic pressure cylinder, the output indicating value is an electric current value supplied to a solenoid valve. However, even when the output indicating value is properly detected, a desired driving force may not be generated by only detecting the output indicating value, due to resistance and friction within the shift actuator
65
. Therefore, in addition to the detection of the output indicating value, a rotational number of a rotating portion of the hydraulic pressure motor or a stroke of a piston included in the hydraulic pressure cylinder is detected. However, it may be difficult to detect the output indicating value and to detect the rotational number of the hydraulic pressure motor or the stro
Aoyama Yoshiyuki
Choshi Ryuji
Ichikawa Yoshihiro
Kamiya Mitsutoshi
Miyazaki Takeshige
Aisin AI Co., Ltd.
Cuchlinski Jr. William A.
Pipala Edward
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