192 clutches and power-stop control – Clutches – Torque responsive
Reexamination Certificate
2000-03-03
2001-12-25
Lorence, Richard M. (Department: 3681)
192 clutches and power-stop control
Clutches
Torque responsive
C192S070170, C192S085060
Reexamination Certificate
active
06332521
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a starting clutch which can be used in place of a torque converter in a motor vehicle or the like.
2. Related Background Art
Conventionally, in automatic transmissions (ATs), starting of a vehicle has been effected by torque transmission using a torque converter. Since the torque converter has a torque increasing effect and provides smooth torque transmission in increasing and decreasing torque, the torque converter has been incorporated into various vehicles having an automatic transmission.
On the other hand, the torque converter has a disadvantage because it has a great slip amount in increasing and decreasing torque and therefore is not efficient.
Thus, recently, it has been proposed to use a starting clutch in place of the torque converter, and it has been contemplated that torque is amplified by reducing a gear ratio and increasing the number of speed changes.
FIG. 4
is an axial sectional view of a conventional starting clutch. A conventional technique will be described with reference to
FIG. 4. A
starting clutch
100
includes a multi-plate clutch
101
. Within a clutch case
106
of the multi-plate clutch
101
, friction plates
102
which are output side friction engaging elements, and separator plates
103
which are input side friction engaging elements are alternately arranged. Further, a backing plate
104
is provided at one end in an axial direction. The backing plate
104
is supported by a stop ring
105
at an axial outer side (left in FIG.
4
). On the other hand, at an end opposed to the backing plate
104
, there is disposed a piston
108
arranged within the clutch case
106
with an O-ring
107
there between. The piston
108
is biased toward the right by a return spring
116
so that the separator plates
103
and the friction plates
102
are normally brought to a non-engaged condition. Further, an oil chamber
109
is defined between the piston
108
and the clutch case
106
.
The starting clutch
100
comprises the multi-plate clutch
101
, a housing
110
covering outer periphery of the multi-plate clutch
101
, and a damper
117
disposed between the clutch case
106
and the housing
110
. The housing
110
is connected to an output shaft
111
of an engine, and the damper
117
is constituted by a spring
130
, a retainer plate
113
for holding the spring
130
and a pawl portion
114
for fitting into the spring
130
.
In the starting clutch
100
, when oil pressure is supplied to the oil chamber
109
through an oil passage
115
, the piston
108
is operated to achieve a friction engaging condition.
In the above-mentioned starting clutch
100
, a predetermined clearance is provided for the non-engaged or released condition, and, since the clearance is maintained by the biasing force of the return spring against the piston, the torque is completely interrupted.
FIG. 6
is an axial sectional view of a conventional starting clutch (upper half). The starting clutch
50
is includes a damper device
27
and a multi-plate clutch device
11
and is divided into drive side elements and driven side elements. The drive side elements include a connecting portion
21
to an output shaft of an engine, the damper device
27
, a housing
20
covering the entire apparatus, a clutch case
16
of the multi-plate clutch
11
, and separator plates
13
, a backing plate
14
, a piston
18
and a base ring
37
which are attached to the clutch case
16
. The driven side elements include an output shaft
32
, a hub
31
of the multi-plate clutch
11
, friction plates
12
and a joint ring
38
. The friction plates
12
and the joint ring
38
are attached to a cylindrical portion of the hub
31
. The cylindrical portion of the hub
31
and the joint ring
38
are interconnected via a bottom surface
39
extending radially inwardly.
More particularly, the damper device
27
comprises a spring
30
, a retainer plate
24
secured to an inner wall of the housing
20
by caulking and adapted to hold the spring
30
, and a fitting pawl
23
attached to outer periphery of the clutch case
16
. O-rings
17
are disposed between the piston
18
and an inner wall of the clutch case
16
and between the piston
18
and an outer peripheral surface of the base ring
37
. There is provided a return spring
26
for biasing the piston
18
toward a releasing direction for the multi-plate clutch (right in FIG.
6
), and a member for attaching the return spring
26
is provided on the base ring
37
.
The piston
18
is operated by generating oil pressure in an oil chamber
19
by supplying oil through an oil passage
22
. Further, a snap ring
15
for supporting the friction plates
12
, separator plates
13
and backing plate
14
is arranged an end of an opening of the clutch case
16
, and a seal bearing
36
is disposed between the joint ring
38
and the base ring
37
. Further, resin washers
40
are disposed between the housing
20
and the hub
31
and between the hub
31
and the base ring
37
and between the clutch case
16
and an oil pump plunger
41
.
However, in the conventional technique shown in
FIG. 4
, since there is the clearance, upon starting the vehicle, when an acceleration pedal is depressed, there arises a timelag (time difference) until the starting clutch is tightened, thereby creating idle charging and shock upon tightening.
To eliminate this, various control methods have been proposed to obtain smooth starting or running of a vehicle by achieving smooth tightening of the clutch upon starting. However, such control is very difficult due to dispersion in number of revolutions of the engine.
Further, in the conventional clutch shown in
FIG. 6
, problems regarding compactness and weight-reduction of the clutch, which have been investigated in recent technical developments cannot be solved. The present invention provides a starting clutch in which an axial dimension can be reduced, the number of parts can be reduced and the entire construction can be simplified compared to conventional starting clutches.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a starting clutch in which smooth tightening can be achieved with a simple mechanism, thereby permitting smooth running of a vehicle.
Another object of the present invention is to provide a starting clutch in which a connecting portion between a main body of the apparatus and an output shaft can be simplified, an axial dimension can be reduced compared to conventional clutches, and correct centering can be achieved.
To achieve the above object, the present invention provides a starting clutch having input side elements and output side elements that are frictionally engaged with each other by receiving an axial load from an urging means for permanently urging elements.
Further, a starting clutch is provided according to the present invention, having a multi-plate clutch with a hub, a damper device and a housing for covering the multi-plate clutch and the damper device, wherein an outer peripheral side of the hub of the multi-plate clutch is connected to drive side elements, thereby solving the above problems.
The invention also provides a starting clutch having a wet type multi-plate clutch that is used as a clutch with input side elements and output side elements that are frictionally engaged with each other. Further, an urging spring for biasing a piston toward a direction opposite to an acting direction of a return spring is disposed in the oil chamber.
Further, a sliding condition of the input side elements and the output side elements can be maintained by hydraulic control instead of the spring.
The invention also provides a starting clutch in which smooth tightening and smooth running can be achieved.
Further provided is a starting clutch in which response of operation due to the oil pressure of the piston can be hastened, an axial dimension of the entire apparatus can be reduced compared to conventional apparatus, and smooth tightening and smooth running can be achieved with
Lorence Richard M.
Miles & Stockbridge P.C.
NSK-Warner K.K.
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