Land vehicles – Wheeled – Running gear
Reexamination Certificate
2001-11-13
2003-07-29
Dickson, Paul N. (Department: 3616)
Land vehicles
Wheeled
Running gear
C280S005507, C280S124104, C280S124106, C280S124157, C060S413000
Reexamination Certificate
active
06598891
ABSTRACT:
BACKGROUND OF INVENTION
This invention relates to a suspension system for a four-wheeled vehicle and more particularly to an improved, simplified and more effective suspension system for controlling all running conditions, which the vehicle encounters.
An arrangement has been proposed for suspending four-wheeled vehicles that employs individual shock absorbers at each wheel which have a relatively simple damping arrangement in them. However, the shock absorbers of paired wheels are coupled together with a pressure control mechanism that provides additional damping under certain characteristics. This type of system is show in Japanese Published Application. Hei 06-72127 and in its United States equivalent, U.S. Pat. No. 5,486,018, entitled “SUSPENSION SYSTEM FOR FOUR-WHEELED VEHICLES” issued Jan. 23, 1996 and the assigned to the assignee hereof. That patent shows a number of arrangements of such interrelated suspension systems. One that shows considerable sophistication appears in
FIG. 13
of that U.S. patent and is reproduced here a FIG.
1
. The details of the interrelationship between the various shock absorbers and the control arrangement is shown in more detail in FIG.
2
.
As shown therein, there are four shock absorbers indicated at
11
LF,
11
RF,
11
LR and
11
RR comprising the cushioning units associated with the four wheels of the vehicle at its corners. Each of the shock absorbers
11
is mounted between the wheel suspension system and the vehicle body in a manner, which will be generally described, as will the individual construction of each shock absorber
11
, which are identical.
Each shock absorber
11
includes a body portion
12
that defines a cylinder bore in which a piston
13
is supported. The piston
13
divides the cylinder bore into an upper chamber
14
and a lower chamber
115
. A piston rod
16
extends through the upper chamber
14
and has a trunion
17
for attachment to the wheel suspension system or the vehicle body. A trunion
18
on the cylinder
12
accommodates the other connection.
A passageway
19
extends between the chambers
14
and
15
and has an orifice
21
for providing individual wheel damping control.
The individual shock absorbers
11
are interconnected with each other by means of an interconnecting control arrangement, indicated generally by the reference numeral
22
. This control arrangement
22
includes individual passageways
23
,
24
,
25
and
26
, which interconnect the chambers
15
of the shock absorber
11
LF,
11
RF,
11
LR and
11
RR with a pressure control, indicated generally by the reference numeral
27
.
This pressure control
27
is shown in more detail in FIG.
2
and includes a body
28
in which four cylinder bores
29
,
31
,
32
and
33
are formed. Pistons
34
,
35
,
36
and
37
reciprocate in the cylinder bores
29
,
31
,
32
and
33
, respectively. These pistons
34
,
35
,
36
and
37
are all connected for simultaneous movement by means of a bridging member
38
, which extends into a pressurized gas chamber
39
. This chamber
39
is pressurized to a suitable pressure with an inert gas such as nitrogen.
Thus, each shock absorber chamber
15
is in communication with a respective one of pressure control volumes
41
,
42
,
43
and
44
formed in the control body
28
between the pistons
34
,
35
,
36
and
37
and the cylinder bores
29
,
31
,
32
and
33
, respectively.
Certain of the shock absorber chambers
15
are paired with each other via communicating passageways
45
,
46
and
47
which connect the control pressure chambers
41
and
42
,
42
and
43
, and
43
and
44
together. Flow controlling orifices
48
,
49
and
51
are positioned in the passages
45
,
46
and
47
, respectively.
When each wheel encounters the same obstacle at substantially the same time, each piston
13
will move in its respective shock absorber
11
to decrease the volume in the chamber
15
. This motion is dampened by the flow through the orifice
21
into the chamber
14
. However, since the piston rod
16
extends into the chamber
14
and displaces some of its volume, more fluid is expelled through the conduits
23
,
24
,
25
and
26
than the chambers
14
can accommodate. This excess displaced fluid flows to the chambers
41
,
42
,
43
and
44
, respectively. Since equal volume of fluid is displaced from each shock absorber
11
, the pistons
34
,
35
,
36
and
37
will move uniformly and the control device
27
will provide no additional damping.
If, however, there is a pitching motion, which tends to cause the vehicle weight to shift to the front, there will be more compression in the chambers
15
and
16
of the shock absorbers
11
LF and
11
RF than in the shock absorbers
11
LR and
11
RR. In fact, these shock absorbers will tend to move in the opposite direction. When this occurs, flow will pass through the orifices
48
and
51
from the chambers
41
and
44
into the chambers
42
and
43
, respectively. Hence, this will provide damping from the pitching action, which might otherwise occur in addition to the damping provided by the individual shock absorbers
11
.
In a similar manner, if the vehicle is rounding a curve which tends to cause the body to roll to the right i.e. when making a left-had turn, fluid will flow from the shock absorber
11
LR to the shock absorber
11
RR through the orifice
49
so to resist roll. However, there is no such roll resistance provided at the front and thus, it is very difficult to set the arrangement for overall damping to suit all conditions.
It is, therefore, a principal object to this invention to provide an improved shock absorber and suspension arrangement for a four-wheeled vehicle that will provide good damping for individual wheel suspension travels and also so as to preclude roll and pitch in all directions.
It a further object to this invention to provide an improved and simplified suspension system of this type and that will achieve these results.
SUMMARY OF INVENTION
A first feature of this invention is adapted to be embodied in a suspension system for a vehicle having at least four wheels, each of which is supported for suspension movement by a vehicle body. Each of four damping elements, each having a pair of relatively moveable members defining a respective first chamber, are interposed between a respective one of the wheels and the vehicle body for varying the volume of the first fluid chamber upon suspension movement of the respective one wheel. Each of the damping elements has a respective damping arrangement for damping the flow of fluid from the respective one of the first fluid chambers. A first conduit interconnects a first pair of the first fluid chambers of two of the damping elements and a first control arrangement is provided for precluding fluid flow through the first conduit in response to a first suspension condition and for providing a damped flow through the first conduit in response to a second suspension condition. A second conduit interconnects the second pair of the first fluid chambers of the remaining two of the damping units. A second control arrangement is provided in the second conduit for precluding fluid flow through the second conduit in response to a first suspension condition and for providing a damp flow through the second conduit in response to a second condition. A third conduit interconnects a third pair of the first fluid chambers other than those paired by the first and second conduits. A third control arrangement is provided in the third conduit for precluding fluid flow through the third conduit in response to a first suspension condition and for providing a damped flow through the third conduit in response to a second suspension condition. A fourth pair of the first fluid chambers other than those paired by the first, second and third conduits are interconnected by a fourth conduit. A fourth control arrangement is provided in the fourth conduit for precluding fluid flow through the fourth conduit in response to a first suspension condition and for providing a damped flow through the
Beutler Ernest A
Yamaha Hatsudoki Kabushiki Kaisha
LandOfFree
Suspension for a four-wheeled vehicle does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Suspension for a four-wheeled vehicle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Suspension for a four-wheeled vehicle will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3045824