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Claims  |
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We claim:
1. In a utility vehicle of the type having an internal combustion engine
and hydraulically driven implements operated when selectively actuated,
with pressurized hydraulic fluid derived from a pump driven by said
engine, the improved hydraulic pump comprising:
a pump housing mounted upon said vehicle, and having a pump chamber;
first and second pump gears mounted for rotation within said housing pump
chamber and defining a pump suction side and a pump pressure side
connectable with said implements;
connector means for connecting said first pump gear in continuous driven
relationship with said engine;
suction port means for coupling said pump suction side with a hydraulic
fluid reservoir retained at substantially atmospheric pressure;
a poppet valve coupled intermediate said suction port means and said pump
suction side and actuable to have a closed orientation substantially
blocking passage of said hydraulic fluid into said suction side to derive
a cavitation mode of pump operation and actuable to have an open
orientation permitting the flow of hydraulic fluid from said reservoir
into said pump suction side to derive a fluid pressurizing mode of
operation, said poppet valve including a poppet slidably movable between
open and closed orientations within a valve chamber;
vent means for venting said pump chamber substantially to atmospheric
pressure to avoid ingress of air thereinto during said cavitation mode of
pump operation; and
actuator means for selectively actuating said poppet valve into said open
orientation by coupling one end of said valve chamber with said pump
suction side, and into said closed orientation by terminating said
coupling with said suction side to permit movement of said poppet to said
closed orientation.
2. The hydraulic pump of claim 1 including lubricating duct means coupled
intermediate said reservoir and said pump suction side for effecting the
flow of hydraulic fluid from said reservoir to said chamber sufficient
only to effect adequate lubrication of said first and second gears during
said cavitation mode of operation; and a fluid return line having a check
valve, said return line aiding the movement of said poppet to said closed
orientation upon said actuator means actuation of said poppet valve during
said fluid pressurization mode.
3. The hydraulic pump of claim 2 in which:
said valve means comprises a poppet valve including a poppet movable
between open and closed orientations within a valve chamber; and
said actuator means effects said actuation of said valve means into said
open orientation by coupling said valve chamber with said pump suction
side.
4. The hydraulic pump of claim 1 in which said vent means includes a
passageway extending through said second pump gear and communicating with
said reservoir.
5. The hydraulic pump of claim 1 including lubricating duct means coupled
intermediate said reservoir and said pump suction side for effecting the
flow of hydraulic fluid from said reservoir to said chamber sufficient
only to effect adequate lubrication of said first and second gears during
said cavitation mode of operation and provide vacuum retention of said
poppet at said closed orientation from said suction side.
6. The hydraulic pump of claim 5 including a fluid return line having check
valve means for returning hydraulic fluid from said pump pressure side
said cavitation mode of operation to said valve chamber one end to effect
movement of said poppet to said closed orientation and device.
7. The hydraulic pump of claim 1 in which said actuator means is a solenoid
actuated valve responsive to a said select actuation of a said
hydraulically driven implement to actuate said valve means into said open
orientation.
8. The hydraulic pump of claim 5 in which said vent means includes a
passageway extending through said second pump gear and communicating with
said reservoir.
9. In a truck of a variety having an internal combustion engine serving as
a prime mover, a hydraulic pump driven by said engine, a dump bed and a
hydraulic cylinder assembly including a rod and piston reciprocally
movable within a cylinder chamber between first and second positions for
selectively elevating and lowering said dump bed, the improved hydraulic
control system comprising:
a hydraulic distribution network including a pressure line extending from
said pump, a suction line extending from said pump, and a reservoir
substantially at atmospheric pressure communicating with said suction
line;
first hydraulic valve means hydraulically actuable to apply hydraulic fluid
from said pressure line to said cylinder chamber at said first position
and simultaneously fluid communicate said reservoir with said chamber
second position to effect said bed elevation;
second hydraulic valve means hydraulically actuable to apply hydraulic
fluid from said pressure line to said cylinder chamber at said second
position and simultaneously fluid communicate said reservoir with said
chamber first position to effect said bed lowering;
third hydraulic valve means hydraulically actuable to communicate said
reservoir with said chamber first position to effect a rapid bed lowering
movement;
first switch controlled actuator means for actuating said first hydraulic
valve means;
second switch controlled actuator means for actuating said second hydraulic
valve means;
third switch controlled actuator means for actuating said third hydraulic
valve means;
control means controllably coupled with said first, second, and third
switch controlled actuator means, including first switch means manually
actuable for controlling said first and second switch controlled actuator
means and second switch means manually actuable for controlling said third
switch controlled actuator means for effecting a rapid lowering movement
of said bed of short duration.
10. The improved hydraulic control system of claim 9 in which said second
switch means is a button switch biased to an open orientation.
11. The improved hydraulic control system of claim 9 in which said first,
second, and third switch controlled hydraulic valve means are solenoid
actuated valves.
12. The improved hydraulic control system of claim 9 including
hydraulically actuated pressure compensating valve means coupled with said
second hydraulic valve means for regulating said fluid communication with
said reservoir to effect said bed lowering at a substantially constant
rate.
13. In a truck of a variety suited for snow-ice control wherein a wheel
mounted frame supports an internal combustion engine, a cab and a
hydraulic cylinder driven dump bed, and including an auger mounted
rearwardly of said bed having a hydraulic auger motor and a hydraulic
motor driven spinner for receiving materials deposited thereon at
predetermined rates by said auger, the improved control system comprising:
a hydraulic pump connected in driven relationship with said engine for
powering said auger and spinner hydraulic motors and said hydraulic
cylinder;
solenoid actuated valve means selectively actuable for controlling the
speed of said auger motor;
speed transducer means having a speed output which when multiplied by a
speed calibration constant derives a product signal representing truck
speed;
electronically erasable memory means for retaining said speed calibration
constant, in auger volume constant and auger flow rate constants;
control means including calibration switch means actuable under management
limited access for deriving a calibration mode, processor means for
controllably effecting actuation of said solenoid actuated valve means in
correspondence with said speed product signal, said memory retained speed
calibration constant, said auger volume constant and said auger flow rate
constants, and responsive to said calibration switch means actuation to
enter said calibration mode to effect select alteration of said memory
retained constants.
14. The improved control system of claim 13 in which said memory means and
said control means are mounted within said truck cab.
15. In a truck of a variety having an internal combustion engine, a
hydraulic pump driven by said engine, a dump bed and a hydraulic cylinder
assembly including a rod and piston reciprocally movable within a cylinder
chamber for selectively elevating and lowering said dump bed, the improved
hydraulic control system comprising:
a hydraulic distribution network including a pressure line extending from
said pump, a suction line extending from said pump, and a reservoir
substantially at atmospheric pressure communicating with said suction
line;
first hydraulic valve means hydraulically actuable to apply hydraulic fluid
from said pressure line to said cylinder chamber to effect said bed
elevation;
second hydraulic valve means hydraulically actuable to fluid communicate
said reservoir with said chamber to effect said bed lowering;
third hydraulic valve means hydraulically actuable to communicate said
reservoir with said chamber to effect a rapid bed lowering movement;
first switch controlled actuator means for actuating said first hydraulic
valve means;
second switch controlled actuator means for actuating said second hydraulic
valve means;
third switch controlled actuator means for actuating said third hydraulic
valve means;
control means controllably coupled with said first, second, and third
switch controlled actuator means, including first switch means manually
actuable for controlling said first and second switch controlled actuator
means and second switch means manually actuable for controlling said third
switch controlled actuator means for effecting a rapid lowering movement
of said bed of short duration.
16. The improved hydraulic control system of claim 15 in which said second
switch means is a button switch biased to an open orientation.
17. The improved hydraulic control system of claim 15 in which said first,
second, and third switch controlled hydraulic valve means are solenoid
actuated valves.
18. The improved hydraulic control system of claim 15 including
hydraulically actuated pressure compensating valve means coupled with said
second hydraulic valve means for regulating said fluid communication with
said reservoir to effect said bed lowering at a substantially constant
rate. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
Snow control vehicles as are used by governmental highway system
authorities and the like as well as within private industry typically are
provided as conventional dump trucks which are seasonally modified by the
addition of snow-ice treatment components. Such components will include a
forwardly-mounted plow which is controllable by hydraulic cylinders for
up-down and right-left or angular movement. Upon the rearward end of the
truck dump bed there usually is mounted sand-salt dispensing components
which include a feed auger extending across the back edge of the dump bed.
This auger is rotated by a hydraulic motor to effect movement of material
from the bed onto a rotating spreader disk or "spinner" which functions to
spread the sand-salt material onto the pavement being treated.
Thus, a hydraulic system for such vehicle is called upon to accommodate not
only the dump body hoist but also the variable speed auger, the spinner,
and plow control system. Because of the seasonal nature of snow-ice
control, these latter function-dedicated components find duty only for a
relatively minor portion of the operational life of a truck. Consequently,
economic practicality dictates that the hydraulic system employed be as
simple as possible while still providing adequate control performance. For
example, permanently mounted hydraulic pumps preferably are not elaborate
and thus remain "on line" or actively engaged by the truck motor during
all periods of truck use, elaborate clutching schemes or the like not
being practical from a cost standpoint. In view of their practical
structuring, very often gear pumps are employed for the instant purpose.
This continuous engagement of the hydraulic pump with the truck motor
represents a design trade-off, the penalty for which is the expense of
added energy consumption by the continuously coupled motor-pump
assemblage.
Control features for the hydraulic systems are called upon to vary the rate
of sand/salt distribution both with respect to weather conditions and to
truck operation. For example, the speed of truck movement should be
associated with the rate of material delivery to the pavement. Because
variations in human factor aspects of truck operations can be anticipated,
it also is desirable to both provide an automatic distribution control
feature and a secure distribution parameter selection for management
control regulation of rates of salt/sand distribution. In the latter
regard, ecological considerations may enter into the allowable amounts of
deposition of chemicals such as salt.
SUMMARY
The present invention is directed to an improved hydraulic circuit and to a
hydraulic pump associated therewith suited for dump trucks and
particularly with respect to such trucks when outfitted with hydraulically
driven components utilized for snow-ice control and the like. The
hydraulic pump is of a pump gear type which incorporates a suction side
shut-off valve permitting its performance in a cavitation mode
significantly lowering torque loads on the truck motor during periods of
hydraulic system non-use. Air ingress into the pump cavity during
cavitation mode performance is avoided through a unique venting
configuration. In a preferred embodiment, a poppet type valve is used for
select pump suction side shut-off which is actuated to a performance or
fluid pressurizing mode of operation utilizing a valve coupling of the
suction input of the pump.
The hydraulic circuit includes a valving arrangement for "jogging" the
downward movement of the dump bed of a truck to enhance operator control
over dumping procedures. The latter feature is particularly useful for
such highway repairs as patchwork and the like.
Where the dump truck with which the hydraulic circuit and pump are
incorporated is employed for snow-ice control procedures, it typically
will be provided with a rear mounted auger and a spinner for sand/salt
distribution. The hydraulic circuit employs solenoid actuated valves to
control fluid motors associated with the distribution items. Control over
the solenoid actuated valves is effected by a microprocessor driven
control circuit which is operated from the cab of the truck. To facilitate
the management of snow-ice control, the calibration of the distributing
auger assembly and the determination of distribution rates with respect to
truck speed are provided in conjunction with a key actuated enabling
switch such that alteration to application rates cannot be made by
unauthorized personnel.
A feature of the invention is to provide, in a utility vehicle of the type
having an internal combustion engine and hydraulically-driven implements
operated, when selectively actuated, with pressurized hydraulic fluid
derived from a pump driven by the engine, the improved hydraulic pump
which includes a pump housing mounted upon the vehicle and having a pump
chamber. First and second pump gears are mounted for rotation within the
housing pump chamber and define a pump suction side and a pump pressure
side connectable with the implements. A connector arrangement provides for
connecting the first pump gear in continuous driven relationship with the
truck engine and a suction port provides for coupling the pump suction
side with a hydraulic fluid reservoir which is retained at substantially
atmospheric pressure. A poppet valve is coupled intermediate the suction
port and the pump suction side and is actuable to have a closed
orientation substantially blocking passage of hydraulic fluid into the
pump suction side to derive a cavitation mode of pump operation and is
actuable to have an open orientation permitting the flow of hydraulic
fluid from the reservoir into the pump suction side to derive a fluid
pressurizing mode of operation said poppet valve including a poppet
slidably movable between open and closed orientations within a valve
chamber. A vent is provided for venting the pump chamber substantially to
atmospheric pressure to avoid ingress of air thereinto during the
cavitation mode of pump operation and an actuator provides for selectively
actuating the poppet valve into the open orientation by coupling one end
of the valve chamber with the pump suction side, and into the closed
orientation by terminating the coupling with the suction side to permit
movement of the poppet to its closed orientation.
Another feature of the invention provides, in a truck of a variety having
an internal combustion engine serving as a prime mover, a hydraulic pump
driven by the engine, a dump bed and a hydraulic cylinder assembly
including a rod and piston reciprocably movable within a cylinder chamber
between first and second positions for selectively elevating and lowering
the dump bed, the improved hydraulic control system which includes a
hydraulic distribution network including a pressure line extending from
the pump, a suction line extending from the pump, and a reservoir
substantially at atmospheric pressure communicating with the suction line.
A first hydraulic valve arrangement is hydraulically actuable to apply
hydraulic fluid from the pressure line to the cylinder chamber at the
first position and simultaneously fluid communicate the reservoir with the
chamber second position to effect bed elevation. A second hydraulic valve
arrangement hydraulically actuable to apply hydraulic fluid from the
pressure line to the cylinder chamber at the second position is provided
and this valve arrangement simultaneously fluid communicates the reservoir
with the chamber first position to effect bed lowering. A third hydraulic
valve arrangement is hydraulically actuable to communicate the reservoir
with the chamber first position to effect a rapid bed lowering movement. A
first switch controlled actuator is provided for actuating the first
hydraulic valve arrangement and a second switch controlled actuator is
provided for actuating the second hydraulic valve, while a third switch
control actuator provides for actuating the third hydraulic valve. A
control arrangement is controllably coupled with the first, second, and
third switch controlled actuators and includes a first switch manually
actuable for controlling the first and second switch controlled actuator
means and a second switch manually actuable for controlling the third
switch controlled actuator for effecting a rapid lowering movement of the
bed of short duration.
Another feature of the invention is the provision, in a truck of a variety
suited for snow-ice control, wherein a wheel mounted frame supports an
internal combustion engine, a cab and a hydraulic cylinder driven dump
bed, and including an auger mounted rearwardly of the bed having a
hydraulic auger motor and a hydraulic motor-driven spinner for receiving
materials deposited thereon at predetermined rates by said auger, a
hydraulic pump connected in driven relationship with the engine for
powering the auger and spinner hydraulic motors and the hydraulic
cylinder, an improved control system which comprises a solenoid actuated
valve arrangement selectively actuable for controlling the speed of the
auger motor. Additionally provided is a speed transducer having a speed
output which when multiplied by a speed calibration constant derives a
product signal representing truck speed and an electrically erasable
memory is provided for retaining the speed calibration constants, auger
volume constants and auger flow rate constants. A control is provided
which includes a calibration switch which is actuable under management
limited access for deriving a calibration mode. A processor is included in
the control for controllably affecting actuation of the solenoid actuated
valve arrangement in correspondence with the speed product signal, the
memory retained speed calibration constant, the auger volume constant, and
the auger flow rate constants and is responsive to calibration switch
actuation to enter the calibration mode to effect select alteration of the
memory retained constant.
Other objects of the invention will, in part, be obvious and will, in part,
appear hereinafter. The invention, accordingly, comprises the system and
apparatus possessing the construction, combination of elements, and
arrangement of parts which are exemplified in the following detailed
disclosure and the scope of the invention is indicated in the appended
claims.
For a fuller understanding of the nature and objects of the invention,
reference should be had to the following detailed description taken in
connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of a truck outfitted with typical
implements for snow-ice control;
FIG. 2 is a partial side view of the engine of the truck of FIG. 1 showing
the mounting of a hydraulic pump therewith according to the invention;
FIG. 3 is a schematic representation of a hydraulic pump according to the
invention;
FIG. 4 is a sectional view of a hydraulic pump according to the invention;
FIGS. 5A and 5B combine to provide a schematic hydraulic circuit diagram
showing a hydraulic system employed with the invention;
FIG. 6 is a front view of the panel of a control box incorporated within
the cab of a vehicle incorporating the instant invention;
FIG. 7 is a schematic electrical diagram of a portion of the control system
employed with the invention;
FIG. 8 is an electrical schematic diagram of another component of the
control system of the invention;
FIGS. 9A and 9B combine as labeled to show another portion of the
electronic control system of the invention;
FIG. 10 is a flow chart showing the general control program employed with
the invention;
FIG. 11 is a flow chart showing a subroutine called in conjunction with the
program of FIG. 10;
FIGS. 12A-12D are a calibrate subroutine which may be called in conjunction
with the general program represented in FIG. 10; and
FIG. 13 is a status subroutine which may be called by the general program
represented in FIG. 10.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a utility vehicle employed for the seasonal duties of
snow-ice removal is revealed generally at 10. The dump truck 10 includes a
cab 12 and hood 14 mounted upon a frame 15. At the forward end of the
truck 10 there is mounted a snow plow 16 which is elevationally maneuvered
by an up-down hydraulic cylinder assembly 18. Additionally, the plow 16 is
laterally, angularly adjusted by left and right side hydraulic cylinder
assemblies, the left side one of such assemblies being represented at 20.
Truck 10 supports a dump bed 24 which is elevated about pivot connections
at frame 15, one of which is shown at 26. This elevating action is carried
out by actuation of a hydraulic cylinder assembly 28 which will be seen to
further include an arrangement for "jogging" the elevational movement of
the bed 24 permitting a limited rapid or fast down action to jog materials
from the bed when it is used for conventional select material deposition
and the like as may be occasioned with highway patching procedures.
Also seasonally attached to the dump body 24 of truck 10 is a material
distributing auger represented generally at 30 which is rotated by a
hydraulic motor 32. In similar fashion, a rotating disk spreading device
or "spinner" is shown generally at 34. Spinner 34 distributes the sand
and/or salt directed thereto by the auger 32 and, in this regard, is
driven by another hydraulic motor 36. Hydraulic lines leading to the
various hydraulic cylinders and motors are shown as an array thereof 38
which extend from a manifold 40, in turn, extending outwardly from
electronic components within the protective environment of the cab 12.
To achieve a highest utility for trucks as at 10, during the majority of
seasons, wherein snow-ice conditions are not expected, the plow 16, auger
30, and associated spinner 34 are removed and stored, thus freeing the
truck 10 for practical utilization. However, during such intervals, it is
economically mandated that the hydraulic pump providing hydraulic power to
all of the above-noted implements remain in place, particularly, inasmuch
as it is employed to carry out dump bed 24 lifting activity using cylinder
28. Additionally, even during months of weather wherein snow-ice
conditions re contemplated, the amount of usage of the various
hydraulically driven implements represents a relatively smaller percentage
of overall truck 10 operations. Thus, should a hydraulic pump assembly be
made available which minimizes the amount of energy extracted during
non-hydraulic utilization while remaining of practical cost, significant
savings can be realized in terms of fuel consumption reductions alone. The
hydraulic pump assemblage described herein exhibits that desirable
attribute.
Looking to FIG. 2, a side view of the motor retaining portion of truck 10
beneath hood 14 is revealed. This region includes the motor 44 and
associated radiator 47. One output of the motor 44 deriving from its
crankshaft is provided at pulleys 46 which, in turn, are coupled by two
V-belts 48 to pulleys 50 which, in turn, drive the input of a gear pump
assemblage represented at 52. Gear pump assemblage 52 receives fluid from
a relatively larger diameter suction line 54 which extends to a tank or
reservoir at atmospheric pressure. Hydraulic fluid under pressure for
implement actuation is provided at pressure line 56 from the pump
assemblage 52.
Pump 52 functions in a demand mode in that when actuation at any of the
hydraulic devices is called for, the pump automatically is enabled to
provide an output of pressurized hydraulic fluid at line 56 which may be
referred to as a fluid pressurizing mode of operation. On the other hand,
when such hydraulic actuation activity is not called for, the pump
automatically will have reverted to a stand-by form of driven actuation
wherein only very minimal energy demands are made by it of the motor 44.
This standby operation may be referred to as a cavitation mode. Pump 52 is
of a gear pump variety and during this stand-by mode the gear pump
components are operated in a cavitational mode wherein essentially no
fluid is driven by the gear components of the pump. In effect, the torque
load to the crankshaft of motor 44 with respect to the demands of pump 52
approaches a zero value. This stand-by cavitational mode of operation is
developed essentially hydraulically, a suction shut-off valve being
employed in conjuction with components which prevent the ingestion of
atmospheric air through the seals of the pump and with an arrangement
providing a lubricating source of oil to prevent thermal build-up and the
like which might otherwise damage the components of the pump.
Looking to FIG. 3, a schematic depiction of the cavitational mode
developing components is revealed. In the figure, a pump assemblage 52 is
shown to have two intermeshed pump gears 60 and 62 within a pump chamber,
gear 60 being driven from the crankshaft of an associated motor through
shaft 64, while gear 62 being mounted for rotation within the pump 52 upon
shaft 66. The pressure side of pump 52 is represented at port 68 and
schematically by line 70. Correspondingly, the suction input to the pump
is represented at 72 and schematically by suction line 74. Control over
the operation of pump 52 with respect to whether it is in a stand-by or
operational mode is provided by a poppet valve assembly represented
generally at 76 and shown to include a poppet 78 which is freely movable
within valve chamber 80. Poppet 78 is shown positioned in an orientation
closing off the suction input 74-72 of pump 52 to cause it to perform in a
cavitational or stand-by mode. This orientation is, for the instant
embodiment, developed by a solenoid actuated valve 82 which is shown in
its unenergized state wherein a pressure line 84 connects pressure output
70 with the upper portion of the valve chamber 80 as represented by line
86. The opposite side of poppet 78 is shown closed against port 88 which
is essentially at atmospheric pressure by virtue of its communication with
the tank or reservoir as represented by line 90, the reservoir itself
being represented at 92. The sealing force applied to poppet 78 for the
closed orientation shown is primarily the pump vacuum exerted from input
74. To maintain lubrication of the gears 60 and 62 and control adverse
thermal effects, a small amount of hydraulic fluid is permitted to enter
the suction side of pump 52 as represented by lines 94 and 96 extending to
suction input 74 and including a small diameter oriface 98 which serves to
regulate fluid quantity to the noted minimal amount. Additionally
communicating with tank or reservoir 92, is a check valve 100 shown
extending within line 102 between line 86 and tank 92. This check valve
100 permits hydraulic fluid from the discharge line 70 to be exhausted
back to the reservoir 92 during a cavitational mode of operation of pump
52. The valve 100 provides for the assertion of a small (i.e. 5 psi)
pressure at line 86 to aid moving poppet 78 to a closed position
particularly when the pump 52 is in other orientations than depicted
wherein the force of gravity aids the movement of poppet 78. For example,
an orientation upside-down with respect to that represented at FIGS. 3 or
4.
When operated in a cavitational mode with the poppet valve in the
orientation shown and the suction side 74-72 of pump 52 closed, it has
been found that air will ingress into the pump cavity rendering such
operation unacceptable. However, this condition is corrected with the
instant design. Generally, the air ingress occurs through the seal of the
pump assembly in consequence of the vacuum otherwise generated during
cavitational operations. Correction is provided by an atmospheric drain or
vent for the cavity of the pump shaft assembly from the tank or reservoir
92 essentially at atmospheric pressure. This atmospheric vent or drain to
the tank is represented in the figure by dashed lines 102 and 104.
When a hydraulic function of truck 10 is called for, then solenoid 82 is
actuated such that suction line 106 is communicated through line 86 to the
poppet cavity 80 to cause the poppet 78 to rise and open the suction port
as represented at line 74. Pump 52 then provides a fluid pressure output
as represented at line 70 which is controlled by an orifice 108 and is
distributed as required into the hydraulic system of truck 10.
Inasmuch as the output at line 70 is of variable flow depending upon the
rate of rotational input from the truck engine, a priority flow control is
provided to regulate the maximum amount of flow available from the pump
assembly. To provide this, a spring operated pressure sensing valve 110
monitors the output pressure at line 70 as represented at dashed line 112
and provides a feedback of excess flow via line 114 which essentially
extends to the suction side of the pump or, in effect, to the tank. With
such an arrangement, should hydraulic functions be implemented while the
truck 10 is moving at a relatively higher speed, excessive reaction times
for the function actuated will be controlled.
An electrically driven or solenoid actuated valve is provided at 82
inasmuch as the control over implements used in a snow-ice removal truck
as at 10 is readily implemented electronically. Thus, a solenoid actuated
device presents a logical technique of providing cavitation or stand-by
modes and operational modes. However, it will be apparent that the
hydraulic system itself can be monitored to achieve the same form of
hydraulic actuation of the poppet valve 76.
Turning to FIG. 4, a sectional representation of the pump 52 is set forth.
In the figure, gears 60 and 62 again are represented as well as shaft 64.
The poppet 78 also is portrayed with the same numeration within cavity 80.
Chamber 80 is seen to be capped by plug 120 and the suction inlet for the
pump is represented at 122. Gears 60 and 62 are seen located within a gear
cavity which further includes several bushings as at 124. The shaft 64 is
shown extending through a seal 126 and the entire assemblage is seen to be
located within a housing 128 assembled together by machine bolts, one of
which is represented at 130.
The atmospheric drain to tank as represented in FIG. 3 by lines 102 and 104
is implemented in the embodiment of FIG. 4 by a combination of bores
including bore 132 extending through the center or axle of gear 62 to open
or communicate with a chamber 134 at the opposite side of gear 66. A
chamber 131 is seen located at one side of gears 60 and 62 and adjacent
seal 126. A chamber 136 adjacent gear 60 is communicated with chamber 134
by a duct or passage 138 and these two passages are shown in communication
with the tank or reservoir by passage or duct 140 extending to the suction
duct 142 leading to the suction port 122. Fluid inlet communication
represented by line 94 and oriface 98 described in conjunction with FIG. 3
are seen in the instant embodiment to be provided by a bore 144
communicating with inlet port 72 and oriface 146 coupled between bore 144
and suction duct 142.
Solenoid 82 is shown coupled within chamber 150 extending to chamber 80 of
the valve assembly 76. The valve includes a spring loaded shuttle or
sliding cylinder 152 having passageways 154-155 extending in
circumferential fashion about the shuttle 152. Passageway 154 is shown in
communication with a passage 160 which, in turn, is in communication with
a pressure port 162 to provide for the assertion of output fluid pressure
on poppet 78 to cause it to assume the closed or cavitational mode or
orientation represented in the figure. When solenoid valve 82 is actuated,
the shuttle or sliding cylinder 152 is withdrawn against the bias of a
spring 164 such that passageway 154 is blocked and passageway 155 is in
communication with passageway 166 which extends via bore 168 to the
suction port. This causes communication of the suction of the pump with
chamber 80 to cause poppet 78 to move into the chamber and open the
suction input.
A pressure relief valve (five pound spring check valve) is represented at
172 which will communicate with the reservoir or tank via duct 174 to
exhaust fluid passing through orifice 146 to tank chamber 150. This valve
corresponds with that described at 100 in FIG. 3.
The hydraulic circuit supply of pressurized fluid by the pump assembly 52
is configured in generally series fashion and is schematically illustrated
in connection with FIGS. 5A and 5B which are mutually associated as
represented by the labeling thereon. Looking to FIG. 5A, fluid flow from
the pump 52 is shown entering at line 190, one portion selectively
entering line 208 and the excess entering a hydraulically actuated by-pass
valve 192. Valve 192 communicates with line 194 which, in turn, extends
via line 196 to hydraulic motor 198. Motor 198 corresponds with the auger
motor described in connection with FIG. 1 at 32. The opposite side of
motor 198 is coupled via line 200 to valve 192. A line 202 is seen
extending from valve 192 to a sequence of four solenoid actuated valves
204-207. The opposites sides of parallel connected valves 204-207 are seen
coupled to line 208. Thus, actuation of one or more of the valves 204-207
effects driving fluid flow to motor 198. Valves 204-207 control the speed
of motor 198 in a digital fashion, each having a binary designated flow
rate. Thus, valve 204 may pass 1 GPM, valve 205 may pass 2 GPM, valve 206
may pass 4 GPM, and valve 207 may pass 8 GPM. By actuating the valve in
different combinations, any flow rate in 1 GPM increments can be developed
for driving the motor 198. In the absence of actuation of any valve
204-207, the resultant pressures as monitored at valve 192 as represented
by dashed lines 210 and 212 effect a by-passing of the motor 198.
The next serially coupled functional implement is a hydraulic motor 214
corresponding with the spinner hydraulic motor 36 described in FIG. 1. In
this regard, line 194 is seen to extend both to a hydraulically actuated
by-pass valve 216 and to a line 230 to one side of a grouping of three
speed controlling solenoid actuated valves 226-228. The opposite sides of
valves 226-228 extend to line 224, in turn, extending a by-pass valve 216.
The opposite side of valve 216 at line 222 extends to motor valve 214
which, in turn, is connected via line 220 to line 218 extending from valve
216. Thus line 218 carries all fluids combined at line 194. As before, the
speed of motor 214 can be regulated in binary fashion by select actuation
of valves within the grouping thereof 226-228. The activity of the latter
valve grouping is monitored by pilot lines as represented at 232 and 234
to effect appropriate by-pass actuation of valve 216.
Line 218 can be dumped to tank via a pressure relief valve 236, the input
to which is coupled to line 218 via line 238. Pressure at line 238 is
monitored by pilot line 240 which functions to retain valve 236 in a
closed orientation. Line 240, in turn, is further controlled by solenoid
actuated valve 242 also connected to the tank. Thus, upon actuation of
valve 242, normally open valve 236 is closed and, fluid flow is directed
along line 218. A variable setting relief valve 244 provides controllable
pressure relief for the system represented by FIG. 5A to avoid excessive
pressure build-up.
Turning to FIG. 5B, line 218 is seen extending to a connection at line 250
with a pressure relief valve 252. Valve 252 serves to dump hydraulic flow
to tank or reservoir in the event of excessive pressure. Line 218
additionally is seen extending to line 254 which, in turn, is tapped by
line 256 which extends to line 258 and valve 260 of the valve pair 260 and
261. Valve 261 is coupled to tank or reservoir via line 262 and each of
the valves 260 and 261 are commonly coupled via lines 264 and 266 to the
rod side of hydraulic cylinder 268. Cylinder assembly 268 corresponds with
a hydraulic dump lift cylinder 28 described in conjunction with FIG. 1.
The opposite side of cylinder 268 is coupled via lines 270, 272, and 274
to hydraulically actuated valves 276-278. Of this three-valve grouping,
valves 277 and 278 are seen coupled, in turn, to tank or reservoir via
line 280 and a pressure compensating valve (spool) 281 which senses the
pressure at line 270 as at line 283 to proportionately restrict the line
280 to tank to assure a uniform rate of lowering of the dump bed 24.
Valves 260-261 and 276-278 are normally held closed by fluid pressure
asserted through check valves 282 and 300 and pilot line 284. This closed
orientation, however, is altered with the select actuation of three
solenoid actuated valves 286-288 which serve as switch controlled
actuators. In this regard, valve 286 is seen connected between tank and
the control inputs to valves 261 and 276 as represented at pilot lines 290
and 292. Thus, upon actuation of valve 286, valve 261 opens line 266 to
tank and valve 276 opens to provide fluid under pressure to line 270.
Correspondingly, valve 287 is seen coupled between tank and pilot lines
294 and 296. Line 296 is seen coupled in control relationship with valves
260 and 277. Accordingly, upon the actuation of valve 287, valve 260 is
opened to provide application of fluid under pressure through line 266 and
valve 277 is opened to vent line 270 to tank. Thus, the typical dump
motion is controllably provided.
Solenoid actuated valve 288 provides the earlier-noted jogging function of
the bed 24 to aid the operator in dumping limited quantities of material
therefrom. In this regard, the valve 288 is coupled between tank and line
298 which, in turn, is connected to valve 278. By momentarily actuating
the valve 288, valve 278, in turn, is opened to tank by effecting an
opening of valve 281 as sensed at line 285 and flow creating a jogging or
rapid downward movement of bed 24. Line 284 also is seen to extend to
another check valve 300 which opens in the event pressure at line 284 is
lower than that at line 270.
Line 254 additionally extends to line 302 extending to one side of solenoid
actuated valve 304. The other side of valve 304 extends via line 306
incorporating check valve 305 and orifice 308 to hydraulic cylinder
assembly 310 which corresponds with hydraulic cylinder 18 described in
FIG. 1 as elevating the plow 16. Also coupled to line 306 via line 312 is
a solenoid actuated valve 314, the opposite side of which is connected to
tank. With the arrangement shown, the plow 16 is elevated by actuation of
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