Machine element or mechanism – Gearing – Interchangeably locked
Reexamination Certificate
1999-10-22
2002-01-08
Estremsky, Sherry (Department: 3681)
Machine element or mechanism
Gearing
Interchangeably locked
Reexamination Certificate
active
06336372
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a vehicle transmission (speed change apparatus) which comprises a speed change ratio change mechanism (speed change mechanism) which can change a speed-change ratio in n shifts, an operating mechanism for operating the speed change mechanism to one of n shifts, an actuator mechanism for driving the operate mechanism, a handle mechanism to be handled in a shift-up direction or shift-down direction, and an ECU (Electric Control Unit) for controlling the actuator mechanism.
2. Related Art
A vehicle transmission which has a synchromesh-type speed change mechanism or a planetary gear-type speed change mechanism can include an up/down handle portion (for example, an up/down lever) that is handled or shifted in one of the two directions corresponding to an increase/decrease of the speed-change ratio to move the speed-change ratio up or down one shift by one shift or one shift at a time. A conventional vehicle transmission which has the synchromesh-type speed change mechanism and in which the up/down lever is provided is explained below with reference to
FIGS. 4 and 5
.
As shown in
FIG. 4
, a vehicle transmission
1
is provided with a speed change casing
2
, a switch panel
8
which has an up/down lever
7
to be handled or shifted in one of the two directions corresponding to an increase/decrease of the speed-change ratio, and a ECU
9
which detects a shift of the up/down lever
7
and operates the actuator
6
so that the speed-change ratio is increased or decreased one shift at a time. Provided in the speed-change casing
2
is a gear train
3
for speed-change, a plurality of synchromesh mechanisms
4
a
to
4
c
to change (shift) combination of meshed gears of the gear train
3
, an operating mechanism
5
which operates or moves the synchromesh mechanisms
4
a
to
4
c
to change the speed-change ratio of the gear train
3
, and a hydraulic or electrical actuator
6
to drive the operate mechanism
5
.
The operating mechanism
5
is comprised of a shift/select shaft
51
shifted in a shift (axial) direction and a select (rotate) direction by the actuator
6
, and a predetermined number of shift forks (here, three shift forks
52
a
to
52
c
corresponding to five forward shifts and one backward shift) to operate the synchromesh mechanisms
4
a
to
4
c
based on a shift/select movement of the shift/select lever
51
by the actuator
6
. The shift fork
52
b
corresponds to a first shift in which a transmitted torque is largest and the degree of reduced rotation is the smallest, and a second shift; the shift fork
52
a
corresponds to a third shift and a fourth shift; and the shift fork
52
c
corresponds to a fifth shift in which the transmitted torque is smallest and the degree of reduced rotation is largest, and a backward shift. The shift/select shaft
51
and the shift forks
52
a
to
52
c
are connected with each other by a gate member
53
. The gate member
53
connects one of three shift forks
52
a
to
52
c
with the shift/select shaft
51
by the shift/select movement thereof.
The actuator
6
can be comprised of an electrical motor, hydraulic motor or oil/air cylinder, and a cooperating movement convert mechanism, and can move linearly and rotate the shift/select shift
51
or can move linearly and slide the shift/select shaft
51
.
The up/down lever
7
is up-handled (shifted) to increase the speed-change ratio and is down-handled to decrease the speed-change ratio. In order to allow such operation of the up/down lever
7
, as shown in
FIG. 5
, an up (speed increase)-groove
81
which extends in a speed increase direction, and a down (speed decrease)-groove
82
which extends in a speed decrease direction are formed on an operating panel
8
. The up/down lever
7
can be also operated to a neutral position and a backward movement position and so a lateral groove
83
which extends from an intermediate position between the up-groove
81
and the down-groove
82
to the neutral position, and a backward movement groove
84
which extends from the lateral groove
83
in parallel with the up-groove
81
are also formed.
In the above vehicle transmission, when the up/down lever
7
is shifted into the up-groove
81
during starting of the vehicle for example, the ECU
9
detecting this shift selects the shift fork
52
b
for the 1st shift or the 2nd shift and sends to the actuator
6
a command to shift the gear train
3
to a side of an input shaft A. The actuator
6
rotates the shift/select shaft
51
to connect it with the shift fork
52
b
via the gate member
53
, and then it moves the shift/select shaft
51
to the side of the input shaft A. Thus, the shift fork
52
b
is moved to the same side so that the synchromesh mechanism
4
b
is operated by a fork
54
b
provided at a tip end of the shift fork
52
b
to change the gear train
3
to the 2nd shift.
On the other hand, when the up/down lever
7
is shifted into the down-groove
82
, the ECU
9
detected this shift selects the shift fork
52
b
and sends to the actuator
6
a command to shift the shift fork
52
b
to a side of an output shaft B. Thus, the synchromesh mechanism
4
b
and the gear train
3
are shifted to the 1st shift.
In the above vehicle transmission, while the vehicle is running in the 3rd shift, if the up/down lever
7
is shifted into the up-groove
81
, the transmission is changed up to the 4th shift by operation of the shift/select shaft
51
, the gate member
53
and the shift fork
52
a
. If the up/down lever
7
is shifted into the down-groove
82
, the transmission is changed to the 2nd shift by operation of the shift/select shaft
51
, the gate member
53
and the shift fork
52
b
. This speed increase or speed decrease one shift by one shift is carried out by every shift of the up/down lever
7
into the up-groove
81
or the down-groove
82
, or by leaving the up/down lever
7
in the up-groove
81
or in the down-groove
82
.
During vehicle driving, there are situations where a driver wishes to change the 5th shift to the 3rd shift or to the 2nd shift at a stroke when the vehicle is running on an ascending road for example, or to change the 3rd shift to the 5th shift when the vehicle is running on a descending road (such shift is called “skip-shift” hereinafter). In the conventional vehicle transmission, the speed-change can be carried out only one shift by one shift, so that the driver should shift the up/down lever
7
into the up-groove
81
or the down groove
82
twice or thrice for the skip shift. Such shift however needs a long time for the speed-change operation, and delays the speed increase/decrease response of the vehicle, which does not satisfy the driver's requirement.
SUMMARY OF THE INVENTION
The present invention is made in view of the above circumstances and intends to provide the vehicle transmission in which the vehicle speed can be changed by a one shift or a skip shift selectively based on the intention and shift operation of the driver. Here, “one-shift” means the vehicle speed is changed from the x-th shift to the (x+1)th shift or to the (x−1)th shift, in a vehicle transmission having the speed change mechanism to be changed in n shifts including m forward shifts and (n-m) backward shifts. Also, “skip-shift” means the vehicle speed is changed from the x-th shift to the (x+2)th or more shifts or to the (x−2)th or lesser shift (here, the relationship 3≦×≦(m−2) is satisfied).
In order to achieve the above object, the vehicle transmission according to the present invention is comprised of a speed change mechanism capable of changing the speed-change ratio in n shifts; an operating mechanism having n operating routes to changing the speed-change ratio of the speed change mechanism in one of n shifts via any of n operating routes; an actuator mechanism for driving the operate mechanism; a one-shift handle portion adapted to be handled to one-shift the speed change mechanism; a skip-shift handle portion handled to skip-shift the speed ch
Ito Yoshiki
Ogami Shiro
Aisin Ai Co., Ltd.
Burns Doane , Swecker, Mathis LLP
Estremsky Sherry
Parekh Ankur
LandOfFree
Vehicle transmission does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Vehicle transmission, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Vehicle transmission will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2848990