U.S. patent number RE33,835 [Application Number 07/605,559] was granted by the patent office on 1992-03-03 for hydraulic system for use with snow-ice removal vehicles.
This patent grant is currently assigned to H.Y.O., Inc.. Invention is credited to James A. Kime, Gregory R. McMenamin.
United States Patent |
RE33,835 |
Kime , et al. |
March 3, 1992 |
Hydraulic system for use with snow-ice removal vehicles
Abstract
A hydraulic system is provided including a hydraulic pump which
is continuously coupled with the engine of a utility such as a dump
truck utilized for snow-ice removal. When hydraulic implements
employed on the truck are not actuated, the pump operates in a
cavitation mode. During this cavitation mode of operation, there is
no ingress of air through seals or the like to a venting of the
gear pump chamber essentially to tank or atmosphere. A poppet valve
is actuated in conjunction with periodic use of hydraulic elements
on the truck to actuate the pump to an operational or pressurized
mode. A key actuated calibrating system is employed to calibrate
snow-ice removal components in a secure manner. Calibration is
provided in conjunction with EEPROM memory.
Inventors: |
Kime; James A. (Columbus,
OH), McMenamin; Gregory R. (Troy, MI) |
Assignee: |
H.Y.O., Inc. (Columbus,
OH)
|
Family
ID: |
26931828 |
Appl.
No.: |
07/605,559 |
Filed: |
October 29, 1990 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
238630 |
Aug 30, 1988 |
04089833 |
Feb 6, 1990 |
|
|
Current U.S.
Class: |
239/657;
180/53.4; 239/663; 239/677; 239/684; 298/22C; 37/234; 417/295;
91/31 |
Current CPC
Class: |
F04C
14/24 (20130101); E01C 2019/2095 (20130101) |
Current International
Class: |
E01C
19/00 (20060101); E01C 19/20 (20060101); E01C
019/20 (); B60P 001/16 () |
Field of
Search: |
;180/53.4
;239/657,663,670,675,677,684 ;298/22C ;417/295,310 ;91/6,19,31
;37/234,236,117.5,DIG.3,DIG.7 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Kashnikow; Andres
Assistant Examiner: Merritt; Karen B.
Attorney, Agent or Firm: Mueller and Smith
Claims
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. .Iadd.
19. 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 dump bed, and including an auger mounted rearwardly of said
bed having a hydraulic auger motor and a spinner having a hydraulic
spinner motor 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 supplying hydraulic fluid under pressure for powering said
hydraulic auger and spinner motors and having a pump output
line;
a first array of solenoid actuated valves hydraulically parallel
coupled, from first to last, having a first common array input
coupled with said pump output line, and selectively actuable to
establish a select hydraulic flow rate at a first common array
output for controlling the speed of said auger motor;
a first valve coupled with said pump output line and said first
array of solenoid actuated valves and responsive to monitor the
pressures at said first common array input and output and effect
pressure control thereacross; and
control means responsive to a first manually derived select input
for effecting said actuation of select said first to last valves of
said first array of solenoid actuated valves..Iaddend. .Iadd.20.
The improved control system of claim 19 in which each said solenoid
actuated valve of said first array is configured, from first to
last, having a flow rate increasing in binary designated flow rate
increments..Iaddend. .Iadd.21. The improved control system of claim
19 including: a second array of solenoid actuated valves
hydraulically parallel coupled, from first to last, having a second
common array input coupled with said pump output line, and
selectively actuable to establish a select hydraulic flow rate at a
second common output for controlling the speed of said spinner
motor; a second valve coupled with said pump output line and said
second array of solenoid actuated valves and responsive to monitor
the pressures at said second common array input and output and
effect pressure control thereacross; and said control means is
responsive to a second manually derived select input for effecting
actuation of said second array of solenoid actuated
valves..Iaddend. .Iadd.22. The improved control system of claim 21
in which each said solenoid actuated valve of said second array is
configured, from first to last, having a flow rate increasing in
binary designated flow rate increments..Iaddend. .Iadd.23. 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
dump bed, and including an auger mounted rearwardly of said bed
having a hydraulic auger motor and a spinner having a hydraulic
spinner motor 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
and having a pump output line for supplying hydraulic fluid under
pressure for powering said hydraulic spinner motor;
an array of solenoid actuated valves hydraulically parallel
coupled, from first to last, having a common array input coupled
with said pump output line, and selectively actuable to establish a
select hydraulic flow rate at a common output for controlling the
speed of said spinner motor;
a valve coupled with said pump output line and said array of
solenoid actuated valves and responsive to monitor the pressure at
said common array input and output and effect pressure control
thereacross; and
control means responsive to a first manually derived select input
for effecting said actuation of select said first to last valves of
said first array of solenoid actuated valves..Iaddend. .Iadd.24.
The improved control system of claim 23 in which each said solenoid
actuated valve of said array, from first to last, is configured
having a flow rate increasing in binary designated flow rate
increments..Iaddend. .Iadd.25. The improved control system of claim
13 in which said solenoid actuated valve means is comprised of an
array of hydraulically parallel coupled valves, each said valve of
said array, from first to last, being configured having a flow rate
increasing in binary designated flow rate increments..Iaddend.
Description
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 valve
304 and is, in turn, lowered by the actuation of valve 314.
Line 254 also extends to one side of solenoid actuated valve 316
and, through line 318, to one side of solenoid actuated valve 320.
The opposite side of valve 316 extends via line 322 to hydraulic
cylinder 324 representing the right side hydraulic cylinder
assembly for moving plow 16 as described in FIG. 1. Similarly, the
opposite side of valve 320 extends via lines 326 and 328 to
hydraulic cylinder assembly 330 which corresponds with the left
side plow actuating hydraulic cylinder as described at 20 in
connection with FIG. 1. Line 326 is seen tapped by a small orifice
332 extending to tank and, similarly, line 322 is tapped by a
similar orifice 334 extending to tank. With the arrangement shown,
as one solenoid of the pair 316 and 320 is actuated, the other is
not and the corresponding orifice associated therewith provides for
directing fluid in the reversing cylinder of the tank.
The hydraulic system thus described is readily operated on a
convenient control box positioned, for example, within cab 12 of
truck 10 as described in connection with FIG. 1. FIG. 6 shows such
a control box 340 as including an LCD display 342 and a sequence of
rotary switches, toggle switches, and button switches. In this
regard, a toggle switch 344 provides conventional power on and off,
while immediately therebelow a toggle switch 346 is actuated to
move the dump bed 24 up and down. Button switch 348 functions to
carry out the earlier-described jogging of bed 24 by effecting the
actuation of solenoid actuated valve 288 as described in
conjunction with FIG. 5B. A spring biased open button type switch
facilitates the short duration switch actuation required for this
function. Below button 348 is another toggle switch 350 which
serves to selectively actuate solenoid actuated valves 304 and 314
to move the plow 16 up and down. The angular orientation of plow 16
is controlled by movement of a toggle switch 352 and a "blast"
function is carried out by actuation of a switch 354. The latter
function is one wherein, for example, the auger 30 is operated at
maximum available RPM. Above switch 354, a toggle switch 356 serves
a selection of an automatic or manual operation of the spreader
function. Additionally, the switch has an orientation for turning
off the spreader function. When the switch 356 is in an automatic
orientation, the amount of salt and/or sand is distributed
according to the speed of the truck and predetermined inserted
data. When in a manual operational mode, the rate of material
output is manually set by the operator by utilizing the zero to 15
position rotary switch 358 which provides auger speed control. In
similar fashion, an eight-position switch 360 provides for
selective rotational speed for the spinner 34.
A rotary switch 362 services a status switch which selects a
display of miles per hour or pounds per mile depending upon its
orientation.
An important feature of the control resides in the provision for
inserting predetermined rates for deposition as selected at switch
358 in a secure fashion. For this purpose, a key actuated calibrate
switch 366 is provided which may be employed by management to set
the criteria for snow-ice control procedures.
Referring to FIG. 7, the components of the control circuit for the
system of the invention wherein switch inputs are compiled are set
forth in schematic fashion. In particular, the switching
information ultimately is directed to a multi-pin connector
represented in the drawing within a dashed boundary J2. A four
switch array represented generally at 370 serves to input signals
representing, respectively from the top of the array bed down fast
is developed from switch 348; bed up; bed down normal or slowly as
developed from switch 346; plow up; plow down as developed from
switch 350; and plow left and plow right as developed from switch
352. These inputs extend through lead array 372 to corresponding
lead array 374 and thence to inputs at junction J2. An array of
pull-up resistors 376 is coupled to +5 v supply, logic low signal
representing an active condition. An array of leads 378 each line
of which is connected to a pull-up resistor from array 380 to +5 v
carries signals from the selection made at spinner speed switch
360. These inputs are provided to an eight-line to three-line
binary encoder which may be provided, for example, as a type 74148.
The output of device 382 at three-line array 384 is directed to
inputs of connector J2. In similar fashion, the multiple outputs of
the manual auger speed selection switch 358 are directed through
two lead arrays 386 and 388 to the respective inputs of eight-line
to three-line binary encoders 390 and 392. As before, the leads of
array 386 are coupled through discrete pull-up resistors to +5 v
supply as represented at resistor array 394 while, correspondingly,
a similar pull-up resistor array for lead array 388 is provided at
396. The outputs of devices 390 and 392 are directed through AND
gate derived combinational logic as represented at 398 to provide a
three-line output a line array 400 which is directed via array 402
to connector J2 as well as to the input of a quad two-line to
one-line multiplexer 404. The output of multiplexer 404 is seen to
be provided at four-line array 406 which is directed to inputs to
connector J2. Four additional inputs to multiplexer 404 emanate
from line array 408 extending from connections at connector J2. The
respective enable not in and enable out terminals of encoders 390
and 392 are additionally coupled to one input of multiplexer 404
via lines 410 and 412.
A NAND logic is developed at gate 414 for the purposes of asserting
a signal calling for active mode (fluid pressure) operation of the
pump 52 via line 416. The input of gate 414 receives logic input
from three-line array 384 via arrays 418 and 420. Inputs from the
status switch 362 are provided to connector J2 via line array 420,
the leads of which are coupled through discrete pull-up resistors
to +5 v as at resistor array 422.
Finally, switch array 424 is configured to receive an error input
functioning to provide a menu program at display 342 for
trouble-shooting purposes. Additionally within array 424 is a
calibrate switch providing for the inputting of application data.
This switch is the key actuated switch 366 used by management.
Additionally, a blast input from switch 354 is received. This same
switch input also draws the initial lead of array 386 to a logic
low via line 426 to cause the auger motor to operate at maximum
speed. Finally, the manual and auto selection switch 356 input is
provided within array 424. Array 424 is coupled, in turn, to line
array 428 which, in turn, is connected through corresponding
pull-up resistors of array 430 to +5 v and to connector J2. The
manual-auto information as well as blast information further is
directed via three-line array 432 to AND gate logic at gate array
434, thence via lines 436 and 438 to the select and output control
ports of multiplexer 404.
Referring to FIG. 8, the arrangement for deriving the LCD display
342 is revealed. In this regard, another connector represented
within dashed boundary J1 is provided which performs through the
line array represented at 450 with a type 65C22 peripheral
interface adapter (PIA) 452. Adapter 452 is one of four such
devices provided in the circuit and may be selected, for example,
as a type W65C22 marketed by The Western Design Center, Inc., Mesa,
Arizona 85203. Adapter 452, in turn, through line array 454
provides the data inputs D0-D7, while the read/write terminal is
driven from line 456; the enable terminal from line 458 and the RS
terminal is driven from line 460.
Turning now to FIGS. 9A and 9B, the logic components of the control
circuit are revealed. Contained in the figures also are the
corresponding connector positions for earlier-described connectors
J1 and J2 which are labeled accordingly. The control circuit
functions in conjunction with a type 8085 microprocessor 470 having
a 1 MHz clock input at 472 and its RST6.5, RST7.5, and CLOCK OUT
terminals coupled, respectively, from top to bottom with line array
474 which includes lines 476, 478, and 480. The SOD, RD, WR, and
ALE terminals are coupled to lines at array 482, the SOD terminal
being coupled via line 484 along with a line 486 extending to the
reset or power up circuit 488. Device 488 also includes a watchdog
input responding to the output of the SOD terminal which is coupled
with line 484. The terminal provides a toggling output every 11/2
seconds in order to avoid a reset function occurring. Address line
array 490 is coupled to the A8-A15 terminals of microprocessor 470
and is directed to a type 74HC244 buffer 492 while the address
lines AD0-AD7 within array 494 are connected to a type 74HC373
eight-bit latch 496. These leads of array 494 also are coupled to a
bi-directional type 74HC245 buffer 498 whereupon they are directed
to connector J1 as noted as well as to bus 500. The AD0-AD7 as well
as A8-A12 terminals of microprocessor 470 additionally are coupled
to a type 2764 EPROM 502 as well as to a type 2817 EEPROM 504 and
to a type 6264 8 K byte RAM 506. The 0-7 terminals of components
502, 504, and 506, in turn, are coupled bus 500 which additionally
is seen to extend to a type 65C22 peripheral interface adapter
(PIA) 508. Terminals within the bracketed terminal region 510 of
PIA 508 include in sequence from the top of the device the
terminals RS0, RS1, RS2, RS3, R/W, TRO, 2, CS2, CS1, and RESET.
These terminals are seen to be coupled to bus 512 which extends in
common to the same input terminals of an identical PIA 514 shown in
FIG. 9B as well as to identical PIA 516 via connecting bus 518. PIA
514 also is coupled to bus 500 via connecting bus 520 and, in
similar fashion, PIA 516 is coupled to bus 500 via connecting bus
522.
FIG. 9A also reveals a type 74138 decoder 524 controlled from
microprocessor 470 via line groupling 526 which functions to
provide chip select outputs for EPROM 502, EEPROM 504, RAM 506, and
the four peripheral interface adapters (PIA) 508, 514, 516 and 452
(FIG. 8). Truck speed information is provided to the control system
through an opto-isolator network 528 having an output at line 530
which extends to one line of line array 532 extending from port B
of PIA 516. The latter line array 532 also extends to terminals of
connector J2. Port A of PIA 508 is coupled to line array 534 which
as seen in FIG. 9B also extends to positions within connector J2
and port B of the PIA 508 is seen to be coupled via line array 536
to the same connector position at connector component J2.
The output ports A and B of PIA component 514 are coupled via line
array 540 and 542 to the actuating input of a sequence of 16
transistors represented at the array 544. These devices may be
provided, for example, as type LM1951 Solid State 1 Amp Switches
marketed by National SemiConductor Corporation. The active low
signals derived from these ports are inverted by the inverter array
546 and the outputs of the transistors are represented at line
array 548. These lines extend to the appropriate solenoid actuated
valves discussed hereinabove. In the event of an error, for
example, represented by an open mode or a short circuit, the
affected transistor switch of array 544 will provide an error
signal which is directed via line arrays 550 and 552 to the inputs
of respective 8 to 1 line multiplexers 554 and 556 which may, for
example, be provided as type 74HCT151. The outputs of multiplexers
554 and 556 are provided at respective lines 562 and 564. The
devices are enabled from bus 536 via respective line arrays 550 and
560. Solenoid valve 82 (FIG. 3) which enables the pump 52 is
actuated in response to a signal calling for the actuation of any
one of the functional solenoid valves providing for truck bed
movement, plow movement, auger movement, and spinner movement.
These actuating signals are tapped from line array 540 by array 570
and directed to the input of an NAND gate 572. This output is
directed via line 574 to line 576 to one input of NAND gate 578.
The opposite input to gate 578 at line 580 emanates from connector
J2 and the output of gate 578 at line 582 is directed to a
transistor switching stage 584 which functions to actuate the noted
enabling solenoid. Stage 584 may be provided as an above-noted type
LM1951.
Turning to FIG. 10, a flow chart representing the general control
program carried out by the microprocessor function 470 is revealed.
The program commences as represented at start node 590 and carries
out static RAM testing as represented at block 592. Next, as
represented at block 594 the peripheral interface adapters 452,
508, 574 and 516 are set-up and, as represented at block 596, the
LCD display 342 is initialized and the opening trademark is
published thereat. A one second delay then ensues as represented at
block 598 to permit readability of the trademark at the display
and, as represented at block 600, a 25 millisecond interrupt timer
is initialized and started. The main program then continues as
represented at line 602 and block 604 to check for any systems
failure, for example the errors detected from outputs of
multiplexers 554 and 556 in conjunction with FIG. 9B. Where an
error is found, then a subroutine, ERRORDT is called. The program
then proceeds to a sensor polling function represented at block
608. This portion of the routine permits a variety of desired
sensors to be positioned, for example, about truck 10 to evaluate
its operating performance. The program then continues as
represented at line 610 and block 612 to determine whether or not
the key actuated calibrating switch 366 has been activated. In the
event that it has, then a CALIBRATE subroutine is called. As shown
at line 614 and block 616, status switch 362 is checked and a
STATUS subroutine is called. Line 618 and block 620 show the
program then progressing to update the display 342 by calling the
display subroutine. As represented at line 622 and node A, the main
program then loops as represented by the coupling of line 622 with
line 602.
Turning to FIG. 11, the error detection subroutine is revealed. The
error detect routine looks to the outputs of the error signal
organizing multiplexers 554 and 556 described in conjunction with
FIG. 9B and responding to error outputs from the transistor array
554. Thus, two components are poled in conjunction with the
subroutine. As represented at block 644, a counter is set to a
first count following which, as represented line 646 and block 648,
the multiplexer selects are set to the count at hand. Then, as
represented at line 650 and block 652 any error flags from the
multiplexer outputs are inputted to the system and as represented
at line 654 and decision block 656, a determination is made as to
whether there is an error from the first multiplexer output. In the
event there is, then as represented at line 658 and block 660, an
error transistor count information is positioned within the display
buffer. The routine then continues as represented at lines 662, 664
and block 666 to update the display and apprise the operator as to
the location of the error. The program then loops as represented at
line 668 leading to line 642.
In the event there is no error represented at the first
multiplexer, then as represented at line 670 and block 672, a
determination is made as to whether error information is present at
the second multiplexer. In the event that it is, then as
represented at line 674 and block 676, an error transistor message
along with count information is placed in the display buffer. The
program then progresses as represented at line 664 and block 666 to
update the display with error information and a loop is completed
as represented at lines 668 and 642. In the event the determination
at block 670 is that there is no error present, then as represented
at line 678 and block 680, the count is incremented by 1. The
program then continues as represented at line 682 and block 684 to
determine whether or not the count has reached a value of 8. In the
event that it has not, then as represented at line 686, the routine
loops to line 646 to continue. In the event that eight such counts
have been developed, then as represented at line 688 and node B the
subroutine returns to the main program, the latter line 688 being
represented in FIG. 10.
Where the calibrate subroutine is called as described in
conjunction with block 612 in FIG. 10, the control system will have
been placed in a mode wherein the management has determined to set
the parameters for salt/sand distribution as well as to accommodate
the distribution components to individual truck vagaries. This
subroutine is represented in FIGS. 12A-12D. Looking to FIG. 12A,
the calibrate routine is entered at node 700 and is represented at
line 702 and block 704, a determination is made as to whether the
calibrate switch 366 has been set. In the event that it has not,
then as represented at line 706, the routine returns as represented
by node C and the same line numeration in FIG. 10. Where the
determination at block 704 is in the affirmative, then a calibrate
mode is at hand and as represented at line 708 and block 710, a
determination is made as to whether the status switch is set at a
zero value. The latter switch is represented at 364 in FIG. 6.
Where a zero state is present, then a calibration with respect to
miles per hour is undertaken and, as represented at line 712 and
node C0, the subroutine represented in FIG. 12B is carried out.
Looking to the latter figure, the routine commences as represented
at line 714 and block 716, the apparent rate of speed in miles per
hour which the control system considers the truck to be traveling
at is placed in the display buffer. As represented at line 718 and
block 720, these data then are displayed to the individual carrying
out the calibration procedure. Generally, the truck will be moving
at a given speed as represented by a speedometer on the highway or
be operating within a speed calibrating fixture. The routine then
continues as represented at line 722 and block 724 to determine
whether the plow up-down switch 350 is in the up orientation. In
the event that it is, then the operator is indicating that the
displayed apparent speed is not equivalent to actual speed and, as
represented at line 726 and block 728, this switch actuation will
increment the speed calibration constant and update the displayed
miles per hour. The routine then continues as represented at lines
730 and 732 to the main subroutine of FIG. 12A as represented at
node B and the noted line 732. Where the inquiry at block 724
results in a negative determination, then as represented at line
734 and block 736, a determination is made as to whether the plow
vertical control switch 350 is in a plow down orientation. In the
event that it is, then the operator will have determined to
decrement the displayed miles per hour. Accordingly, as represented
at line 738 and block 740, the speed calibration constant is
decremented and the results thereof are displayed. The routine then
continues as represented at lines 742, 730, and 732 to return to
the calibration routine. In the event of a negative determination
at block 736, the same return as represented at line 730 and node D
is carried out.
Returning to FIG. 12A, where the determination at block 710 is in
the negative, then as represented at line 750 and block 752, a
determination is made as to whether the status switch is at a logic
1 and whether the auger switch 358 is in a zero orientation. In the
event of a negative determination, then as represented at lines 754
and node C2, the routine progresses to the subroutine represented
in FIG. 12C. Looking to that figure, the subroutine commences as
represented at line 756 and block 758 to examine the auger rotary
switch 358 and obtain the auger flow rate which had been previously
set therein. Such data are provided in a tabulation retained within
EEPROM 504 (FIG. 9B). The subroutine then continues as represented
at line 760 and block 762 wherein the auger flow rate so selected
is placed in the display buffer. As represented at line 764 and
block 768, the display then is updated with that information and as
represented at line 768 and block 770, a determination is made as
to whether the plow vertical switch 350 is in an up orientation. In
the event that it is, then the calibrating individual has
determined to increment an auger flow rate constant to a new value
as represented by line 772 and block 774. The subroutine then
returns to the basic calibrate routine as represented at lines 776
and 778 leading to node D and line 732 extending to line 702.
Where the determination at block 770 is in the negative, then as
represented at line 780 and block 782, a determination as to
whether the plow switch 350 is in an orientation for plow down. In
the event of an affirmative determination, then as represented by
line 784 and block 786, the auger flow rate constant representation
is incremented and the routine returns as represented at line 788,
776, and 778. The resultant alteration of the auger flow rate
constant is retained in the noted EEPROM 504.
Returning to FIG. 12A, where an affirmative determination is made
at block 752, then as represented at line 800 and node C1, the
subroutine represented at FIG. 12D is entered. This subroutine is
one wherein the material output rate developed by the auger on the
truck is adjusted. Looking to FIG. 12D, the subroutine is entered
as represented at node C1, line 802, and block 804. The auger
volume constant is the amount of material such as salt outputted by
the auger in pounds per minute at a motor flow of one gallon per
minute. The constant may be either calculated or measured, the
value then is placed in the display buffer and as represented at
line 806 and block 808, the display is updated with that value. The
subroutine then continues as represented at line 810 and block 812
to determine whether the plow vertical orientation switch 350 is in
a plow up orientation. In the event that it is, then as represented
by line 814 and block 816, the value displayed for the auger volume
constant is incremented to the extent desired by the calibrating
operator. The subroutine then returns as represented by lines 818,
820, and node D.
Where the determination at block 812 is in the negative, then as
represented at line 822 and block 824 a determination is made as to
whether the switch 350 is in a plow down orientation. In the event
that it is, then as represented at lines 826 and block 828, the
auger volume constant is decremented to an extent desired by the
calibrating operator and the subroutine returns as represented by
lines 830, 820, and node D.
Block 616 of the main program described in conjunction with FIG. 10
calls for a status subroutine functioning to determine the status
of switch 362. Looking to FIG. 13, the status subroutine is shown
entered at node 850 and line 852 leading to the inquiry at block
854. A determination is made as to whether the switch is in a
select orientation here designated as zero. In the event that it
is, then as represented at line 856 and block 858, the truck seed
in miles per hour is positioned in the display buffer as
represented in the main program block 620. The subroutine then ends
as represented at lines 860 and 862. Where the determination at
block 854 is in the negative, then as represented at line 864 and
block 866, a determination is made as to whether the status switch
is in a position equal to or greater than one. Where that is the
case, then as represented at line 868 and block 870, a pounds
representation of operation is placed in the display buffer for
display and the subroutine returns as represented by lines 872,
860, and 862 and node A.
Since certain changes may be made in the above-described system and
apparatus without departing from the scope of the invention herein
involved, it is intended that all matter contained in the
description thereof and shown in the accompanying drawings shall be
interpreted as illustrative and not in a limiting sense.
* * * * *