Field of the Invention
The present invention relates to an apparatus with a hydraulic system.
More particularly the present invention also relates to an apparatus with a
hydraulic system which have the improved ride control system.
Still more particularly, this present invention also relates to a method and
apparatus having a dampening the shocks in a construction industry vehicle with
front end loader.
Background of the invention
It is well known that when a machine, such as a wheel loader, backhoe loader,
with a loaded/ unloaded bucket is driven there is always the possibility that the
machine will lope or bounce due to the weight of the loaded! unloaded bucket
reacting to the machine encountering rough terrain or other obstacles. In order
to help reduce or eliminate this lope or bounce it is know to use accumulators
that are selectively connected to the lift actuators. With the accumulator
connected to the loaded end of the lift actuator pressure fluctuations in the
actuators is absorbed thus offsetting changing forces acting on the tires of the
machine. It is the changing forces acting on the tires of the machine that
pr()duces the lope or bounce. In order to maintain' a pre-charge in the
accumulator equal to the pressure in the loaded end of the actuators, it is known
to connect the accumulator, during normal use, to the loaded end of the lift
actuators by connecting a conduit there between. The conduit normally has a
2
valve, having an orifice, that is selectable moved to dispose the orifice within
the conduit when the machine is nut operating in the ride control mode. It has
been found that during some situations that the pressure in the accumulator may
not be equal to the pressure in the loaded end of the lift actuator when the ride
control is activated. The pressure not being equalized could allow the load to
"drop" slightly or "jump" thus adding to the problem of machine bounce or
subjecting the machine to a "jolt" Furthermore, it has been found that in
previous systems, the ride control is always functional, once activated, even
though operating conditions would be better if the ride control were turned off.
Various types of off-road or construction vehicles are used to perform
excavation functions such as leveling, digging, material handling, trenching,
plowing, etc. These operations are typically accomplished with the use of a
hydraulically operated bucket, backhoe or other implement. These implements
include a plurality of linkages translationally supported and rotationally
supported, and are moved relative to the supports by hydraulic cylinders or
motors. As a result of the type of work these machines are used to perform (i.e.
job site work) these machines are often required to travel on roads between job
sites. Accordingly, it is important that the vehicle travel at reasonably high
speeds. However, due to overhang of the implements supported on the vehicle,
vehicle bouncing, pitching or oscillation ,?ccurs at speeds satisfactory for road
travel.
3
It is well known that when a machine, such as, for example, a wheel loader, is
being driven for a distance with a loaded/unloaded bucket there is always the
possibility that the machine will be subjected to shocks due to the weight of the
loaded bucket reacting to the machine encountering bumps or other obstacles in
its pathway. In order to help reduce or eliminate shocks, it is known to use
accumulators that are selectively connected to the lift cylinder actuator. These
accumulators, when connected to the loaded end of the actuators, serve to
absorb the pressure fluctuations in the actuators thus offsetting the changing
,
forces that would otherwise be acting on the various components of the
machine. It is these changing forces acting on the machine that produces the
shocks. In order to maintain a pre-charge in the accumulator equal to the
pressure in the loaded end of die actuators, it is known to connect the
accumulator, during normal use, to the loaded end of the lift cylinder actuator.
This is normally accomplished by connecting a conduit therebetween. The
conduit normally has an orifice therein that is selectively disposed in the conduit
when the machine is not operating in the ride control mode. When the ride
control system is active, the load supporting end of the cylinder is in free
communication with the accumulator in order to absorb the changing forces. It
has been found in at least some situations that the degree of damping during ride
control should be varied based on the magnitude of the shock to the machine.
4
The known Japan Patent No.2000-309953 describes the suppressing of these
vibrations, a bottom pressure chamber of a boom cylinder and an accumulator
are brought into communication with each other during traveling to have
pressure fluctuations in the bottom pressure chamber absorbed in the
accumulator, and during digging work with a bucket, on the other hand, the
communication with the accumulator is cut off to prevent the absorption of
digging force in the accumulator. As a conventional technique of this sort,
reference can be made to.
The other known German Patent No. 102009003472 states that the closed ride
level control system for vehicles, through which a vehicle body relative to at
least one vehicle axle is sprung, containing the following ingredients:-pressure
J \.1,
medium chambers, which branches with a pressure medium line, respectively,
- a compressor, - an air dryer which is arranged in a pressure medium line, - a
pressure fluid supply reservoir via' the compressor with the pressure medium
chambers being in communication - that pressure medium from the pressure
fluid reservoir via the compressor into each pressure medium chamber can be
transferred, said compressor input then over a with a directional control valve
through-connected pressure medium line with the pressure fluid reservoir and
the compressor output then over a with a directional control valve.
5
According to the known Korean Patent No. 20110008946, an electro-hydraulic
ride control system for construction equipment is provided to easily offset
vibration pressure generated in a boom cylinder. An electro-hydraulic ride
control system for construction equipment comprises a hydraulic boom
cylinder, a driving unit, a hydraulic line, an accumulator, a main bidirectional
electro-hydraulic poppet valve, and a pressure control module. The hydraulic
boom cylinder, comprising a head and a rod connected to the head, raises and
lowers a bucket of construction equipment. The driving unit is connected to the
head and the rod of the boom cylinder and provides hydraulic fluid of fixed
pressure to the boom cylinder. The hydraulic line is connected to a head side
first driving line of the boom cylinder. The accumulator is installed on an end of
the hydraulic line. The main bidirectional electro-hydraulic poppet valve is
installed in the hydraulic line. The pressure control module controls the
opening/closing of the hydraulic line using the main bidirectional electrohydraulic
poppet valve in order to maintain the set pressure at the head side and
the rod side of the boom cylinder.
.
The known WIPO Publication No. W02006130282 describes the hydraulic
control system for a work machine is disclosed. The hydraulic control system
has a source of pressurized fluid and at least one actuator having a first and a
second chamber. The hydraulic control system also has a first independent
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metering valve disposed between the source and the first chamber, and a
second independent metering valve disposed between the reservoir and the
second chamber. The first and second independent metering valves each have a
valve element movable between a flow blocking and a flow passing position to
facilitate movement of the at least one actuator. The hydraulic control system
further has an accumulator and a third independent metering valve disposed
between the source and the first independent metering valve. The third
independent metering valve is configured to selectively communicate the
accumulator with the first chamber to cushion movement of the at least one
actuator.
The other known Chinese Patent No. 1776123 discloses the invention which
describes a hydraulic ride control system for a working vehicle such as a wheel
loader is provided with boom cylinders, an actuator control valve for controlling
a pressure in bottom pressure chambers of the boom cylinders, an accumulator
connected to the bottom pressure chambers of the boom cylinders via a
connection line, an opening control valve having a pilot chamber to selectively
communicating or cutting off the connection line depending on a pressure in the
pilot chamber, and a selector unit. for selectively feeding a pressure to or
draining a pressure from the pilot chamber.. The selector unit comprises a
controller for variably controlling an opening of the opening control valve.
7
The invention which is describedin :the;Japanese Patent No. 2001200801 to
provide a hydraulic ride quality control system of a machine, particularly, a
control system selectively preparing a damping ride quality control. This
hydraulic ride quality control system controls the ride quality of a machine
having a load thereon. A ride quality control includes an accumulator device
connected selectively to an actuator supporting the load, prepares a damping
ride quality during running and, when raising the load, allows a pressure in the
accumulator device to be maintained to be substantially equal to a pressure in
the actuator. When the load is reduced, a pressure in the accumulator is allowed
to be reduced to a pressure in the actuator. Also, the ride quality control system
always prepares a device to allow the accumulator device to be depressurized
when the machine is stopped or if the machine lost its function.
Another known US patent No.5,473,990 states that a ride vehicle for used in an
amusement attraction. The ride vehicle mounts a structure upon a hydraulicallyactuated
motion base, so that the passenger holding structure may be articulated
about one or more axes as the vehicle moves. Thus, this "simulator ride" carries
passengers through three-dimensional scenery and articulates the passenger
holding structure in synchronism with motions of the ride vehicle, the motions
of moving show sets, which are external to the vehicle, sound, projection and
other effects. The ride vehicle IS programmably-controlled, and derives
8
electrical power from a track mounted power bus to drive vehicle hydraulics,
which drive motion base actuation, steering and vehicle velocity. The hydraulic
control system uses an electric pump to charge a high-pressure accumulator
with hydraulic power from a 480-volt power supply, a manifold to regulate the
supply of hydraulic energy to motion base and steering actuators and a
hydraulic motor, and a 10w-pressiIre accumulator that aids in regenerative
braking. Using these elements, the computerized vehicle-control system
controls the hydraulically-actuated elements to provide synchronized motions of
the vehicle and passenger holding structure, and other special effects, in
accordance with a selected one of a plurality of ride programs.
As is known well, the ride controbsystem is used to dampen shocks due to
weight overhang of front bucket by absorbing the pressure shocks in an
accumulator.
In the known damping system, the ~hocks are absorbed in the accumulator after
manual switching 'ON' the valves to direct the oil path to accumulator during
travelling or the mechanism is based on speed sensing that means the Ride
Control System gets switched automatically 'ON' if the speed of vehicle exceeds
the normal working speed. The ride control system remains inactive below that
't" _:;;:-;
speed.
9
The main disadvantage of the above systems is that either the system is operator
dependent or it remains inactive at low speeds even if the vehicle is travelling.
The operator can still experience shocks if vehicle is moving at slow speeds and
travelling through rough terrains, or speed breakers.
To solve this problem and to make method and apparatus, simpler and cheaper
an automatic system has been developed which senses the pressure in the
hydraulic circuit to electrically disconnect the accumulator from the hydraulic
circuit.
None of these known patents, however alone or in combination, disclose the
present invention.
Summary of the invention
Accordingly an object of the present invention relates to an apparatus with a
hydraulic system. The present invention also relates to an apparatus with a
hydraulic system having improved ride control system. More particularly, this
present invention also relates to a method and apparatus for dampening the
shocks in a construction industry vehicle with front end loader.
We shall now describe the invention with reference to accompanying drawings
which are given by way of illustration but does not restrict the scope of present
invention
"10,, : '. ,~.
According to the present invention there is provided apparatus with a hydraulic
system having improved ride control system and method for dampening the
shocks using pressure switch method compnses the ride control system
solenoids, Sl and S2, are switched ON; the piston end of the lift ram gets
connected to the accumulator through the spool connected to solenoid S1 and
the rod end of the lift ram gets connected to the tank through the spool
connected to solenoid S2 as shown in the diagram facilitating absorption of
shocks inside the accumulator the oil present in the piston end is free to move
the accumulator membrane up and down in the absence of pressure from the rod
end the solenoids are switched off, the accumulator and tank line are cut-off
,;,;
from the system and the ride control s~st~m stops working.
The ride control system remain inactive during normal working applications
such as loading and dozing.
The switching of the ride control system can be achieved by many means based
on speed or manually.
An automatic method which switches 'ON' the ride control system whenever
required without any human intervention at all speeds and the system uses a
pressure switch to determine the state .of ride control system.
.
The loader of a machine is not being operated, the pressure in the hydraulic
; . .,
circuit will be low as the oil from the pump is dumped to sump in neutral and
11
whenahy hydraulic function is operated, the pressure immediately shoots up
and this pressure jump can be recorded by using a pressure switch which
switches ON above the reset pressure, operating the loader lever will cause the
pressure in the system to rise due to large amount on resistance encountered to
the flow of hydraulic oil and this rise in pressure will be registered by the
pressure switch which would switch OFF the solenoids present in the ride
control system and disconnect the accumulator out of the hydraulic circuit.
Brief description of accompanying drawings:
Fig 1 and 2 shows the working ofthe ride control system;
Fig 3 and 4 shows the position of pressure switch,
Fig 5 shows switches off the solenoids,
Detailed description of the invention with accompanying drawings
Tllere are many possible embodiments of this invention. The drawings and
description below describe in detail a preferred embodiment of the invention. It
should be understood that the present disclosure is to be considered of the
present invention.
The principal object of the invention is to provide an apparatus with a hydraulic
system.
The other embodiment of the invention is to provide an apparatus with a
hydraulic system which have the improved ride control system.
12
The other embodiment of the invention is to provide a method and apparatus
having for dampening the shocks in a construction industry vehicle with front
end loader.
The other embodiment of the invention is that when the loader of a machine is
not being operated, the pressure in the hydraulic circuit will be low as the oil
fr'Jm the pump is dumped to sump in neutral. When any hydraulic function is
operated, the pressure immediately shoots up. This pressure jump can be
recorded by using a pressure switch which switches ON above the reset
pressure.
The advantages and novel features of the invention will become more apparent
from the following detailed description when taken in conjugation with
accompanying drawings and these drawings are illustrative in explaining the
constructional details of the apparatus of the invention. Such drawings are
shown in five sheets.
The above diagram shows the working of the ride control system. When the ride
control system solenoids, Sl and S2, are switched ON, the piston end of the lift
ram gets connected to the accumulat()r through the spool connected to solenoid
S1 and the rod end of the lift ram gets connected to the tank through the spool
connected to solenoid S2 as shown in the diagram. These connections facilitate
absorption of shocks inside the accumulator as the oil present in the piston end
is free to move the accumulator membrane up and down in the absence of
13
p~essure from the rod end. When the solenoids are switched off, the
accumulator and tank line are cut-off from the system and the Ride Control
System stops working.
The invention may be better understood by referring to the following detailed
description, which should be read in conjunction with the accompanying
drawings. The detailed description of a particular preferred embodiment, set out
below to enable one to build and use one particular implementation of the
invention.
In the current invention it is important that the Ride Control System remain
inactive during normal working applications such as loading and dozing.
The switching of the Ride Control System can be achieved by many means, for
example, based on speed or manually.
This draft proposes an automatic method which switches 'ON' the Ride Control
System whenever required without any human intervention at all speeds. This
,
system uses a pressure switch to determine the state of Ride Control System.
When the loader of a machine is not being operated, the pressure in the
hydraulic circuit will be low as the oil from the pump is dumped to sump in
neutral. When any hydraulic function is operated, the pressure immediately
shoots up. This pressure jump can be recorded by using a pressure switch which
switches ON above the reset pressure. Operating the loader lever will cause the
i, \.
pressure in the system to rise due to large amount on resistance encountered to " r- ~,
14
the flow of hydraulic oil and this rise in pressure will be registered by the
pressure switch which would switch OFF the solenoids present in the ride
control system and disconnect the accumulator out of the hydraulic circuit.
The diagram as shown in figures 3 and 4, the position of pressure switch which
has been placed very near to the source of hydraulic oil in the hydraulic circuit.
This position ensures that the Ride Control System is switched 'OFF' even when
oil is entering the ram at rod end at high pressure and exiting the piston end at
low pressure, hence bringing the loader arm down (Fig 3 and 4).
The electrical circuit diagram shown above switches off the solenoids, S1 and
~, ,; t
S2 are present in the ride control.system to disable it so that the hydraulic
operations of the machine can occur properly.
From the foregoing, it will be observed that numerous modifications and
variations can be effected without departing from the true spirit and scope of the
novel concept of the present control system. It will be appreciated that the
present disclosure is intended as an exemplification of the control system, and is
not intended to limit the control system to the specific embodiment illustrated.
The disclosure is intended to cover by the appended claims all such
modifications as fall within the scope of the claims.

WE CLAIM:
I. Apparatus with a hydraulic system having improved ride control system
and method for dampening the shocks using pressure switch method comprises
the ride control system solenoids, 81 and 82, are switched ON, the piston end of
the lift ram gets connected to the accumulator through the spool connected to
solenoid 81 and the rod end of the lift ram gets connected to the tank through
the spool connected to solenoid 82 as·. shown in the diagram facilitating
absorption of shocks inside the accumulator the oil present in the piston end is
free to move the accumulator membrane up and down in the absence of pressure
from the rod end the solenoids are switched off, the accumulator and tank line
are cut-off from the system and the ride control system stops working.
2. Apparatus with a hydraulic s}'stem having improved ride control system
and method for dampening the shocks using pressure switch method as claimed
in claim '1, wherein the ride co'ntrol system remain inactive during normal
working applications such as loading and dozing.
3. Apparatus with a hydraulic system having improved ride control system
and method for dampening the shocks using pressure switch method as claimed
in any of claims 1 or 2, wherein the switching of the ride control system can be
achieved by many means based on speed or manually.
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4. Apparatus with a hydraulic system having improved ride control system
and method for dampening the shocks using pressure switch method as claimed
1, 2 and 3 wherein an automatic method which switches 'ON' the ride control
system whenever required without any human intervention at all speeds and the
system uses a pressure switch to determine the state of ride control system.
5. Apparatus with a hydraulic system having improved ride control system
and method for dampening the shocks using pressure switch method as claimed
1, 2,3 and 4, wherein the loader of a machine is not being operated, the pressure
in the hydraulic circuit will be low as the oil from the pump is dumped to sump
in neutral and when any hydraulic function is operated, the pressure
immediately shoots up and this pressure jump can be recorded by using a
pressure switch which switches ON above the reset pressure, operating the
loader lever will cause the pressure in the system to rise due to large amount on
resistance encountered to the flow ~f hydraulic oil and this rise in pressure will
be registered by the pressure switch which would switch OFF the solenoids
present in the ride control system and disconnect the accumulator out of the
hydraulic circuit.