U.S. patent application number 09/838005 was filed with the patent office on 2002-02-28 for vehicle with supplemental energy storage system for engine cranking.
This patent application is currently assigned to Kold Ban International, Ltd.. Invention is credited to Burke, James O..
Application Number | 20020024322 09/838005 |
Document ID | / |
Family ID | 24617752 |
Filed Date | 2002-02-28 |
United States Patent
Application |
20020024322 |
Kind Code |
A1 |
Burke, James O. |
February 28, 2002 |
Vehicle with supplemental energy storage system for engine
cranking
Abstract
A vehicle having an internal combustion engine that drives a
generator and a cranking motor that cranks the engine is provided
with a standard electrical system as well as a supplemental
electrical system. This supplemental electrical system includes a
capacitor that is charged by the primary electrical system of the
vehicle and is protected against excessive discharge. When it is
desired to start the engine, the capacitor is connected to the
cranking motor to supply adequate cranking power to the cranking
motor, regardless of the state of charge of the batteries.
Inventors: |
Burke, James O.; (Richmond,
IL) |
Correspondence
Address: |
BRINKS HOFER GILSON & LIONE
P.O. BOX 10395
CHICAGO
IL
60610
US
|
Assignee: |
Kold Ban International,
Ltd.
|
Family ID: |
24617752 |
Appl. No.: |
09/838005 |
Filed: |
April 18, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09838005 |
Apr 18, 2001 |
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09652687 |
Aug 31, 2000 |
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6242887 |
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Current U.S.
Class: |
320/166 |
Current CPC
Class: |
F02N 2200/064 20130101;
F02N 2011/0888 20130101; F02N 2200/063 20130101; F02N 11/0866
20130101; F02N 2011/0885 20130101 |
Class at
Publication: |
320/166 |
International
Class: |
H02J 007/00 |
Claims
1. In a vehicle comprising an internal combustion engine, a
generator driven by the engine, a cranking motor coupled with the
engine to crank the engine, and a battery coupled with the cranking
motor, the improvement comprising: a double layer capacitor
characterized by a capacitance greater than 320 farads and an
internal resistance at 1 kHz and 20.degree. C. less than 0.008
ohms; a set of paths interconnecting the generator and the
capacitor, said set of paths comprising a circuit for preventing
the capacitor from discharging excessively and a switch; a switch
controller operative to open the switch automatically to protect
the capacitor against excessive discharge during non-cranking
conditions, and to close the switch automatically during cranking
conditions.
2. The invention of claim 1 wherein the circuit comprises a diode
oriented to pass charging currents to the capacitor and to block
discharging currents from the capacitor.
3. The invention of claim 1 wherein the circuit comprises a
low-voltage disconnect circuit.
4. The invention of claim 1 wherein the switch controller is
operative to hold the switch open except during cranking
conditions.
5. In a vehicle comprising an internal combustion engine, a
generator driven by the engine, a cranking motor coupled with the
engine to crank the engine, and a battery coupled with the cranking
motor, the improvement comprising: a double layer capacitor
characterized by a capacitance greater than 320 farads and an
internal resistance at 1 kHz and 20.degree. C. less than 0.008
ohms; a set of paths interconnecting the generator and the
capacitor, said set of paths comprising first means for preventing
the capacitor from discharging excessively and a switch; second
means for opening the switch automatically to protect the capacitor
against excessive discharge during non-cranking conditions, and for
closing the switch automatically during cranking conditions.
6. The invention of claim 5 wherein the first means comprises a
diode oriented to pass charging currents to the capacitor and to
block discharging currents from the capacitor.
7. The invention of claim 5 wherein the first means comprises a
low-voltage disconnect circuit.
8. The invention of claim 5 wherein the second means is operative
to hold the switch open except during cranking conditions.
9. The invention of claim 1 or 5 wherein the capacitor is
characterized by a storage energy capacity greater than 15 kJ.
10. The invention of claim 1 or 5 wherein the capacitor is
characterized by an internal resistance at 1 kHz and 20.degree. C.
less than 0.006 ohms.
11. The invention of claim 1 or 5 wherein the capacitor is
characterized by an internal resistance at 1 kHz and 20.degree. C.
less than 0.003 ohms.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of copending U.S. patent
application Ser. No. 09/632,653, filed Aug. 31, 2000, which is
hereby incorporated by reference in its entirety.
BACKGROUND
[0002] The present invention relates to vehicles of the type that
include an internal combustion engine, a cranking motor, and a
battery normally used to power the cranking motor. In particular,
this invention relates to improvements to such systems that
increase of the reliability of engine starting.
[0003] A problem presently exists with vehicles such as heavy-duty
trucks. Drivers may on occasion run auxiliary loads excessively
when the truck engine is not running. It is not unusual for
heavy-duty trucks to include televisions and other appliances, and
these appliances are often used when the truck is parked with the
engine off. Excessive use of such appliances can drain the vehicle
batteries to the extent that it is no longer possible to start the
truck engine.
[0004] The present invention solves this prior or problem in a
cost-effective manner.
SUMMARY
[0005] The preferred embodiment described below supplements a
conventional vehicle electrical system with a capacitor. This
capacitor is protected from discharging excessively when auxiliary
loads are powered, and it is used to supply a cranking current in
parallel with the cranking current supplied by the vehicle battery
to ensure reliable engine starting. A battery optimizer
automatically increases the voltage to which the capacitor is
charged as the capacitor temperature falls, thereby increasing the
power available for engine cranking during low temperature
conditions.
[0006] This section has been provided by way of general
introduction, and it is not intended to limit the scope of the
following claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a block diagram of an electrical system for a
vehicle that incorporates a preferred embodiment of this
invention.
[0008] FIG. 2 is a graph illustrating operation of the circuit 42
of FIG. 1.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENT
[0009] Turning down to the drawings, FIG. 1 shows an electrical
system of a vehicle 10 that includes an internal combustion engine
12. The engine 12 can take any suitable form, and may for example
be a conventional diesel or gasoline engine. The engine 12 drives a
generator 14 that generates a DC voltage. As used herein, the term
"generator" is intended broadly to encompass the widest variety of
devices for converting rotary motion into electrical power,
including conventional alternators, generators, and the like. The
engine 12 is also mechanically coupled to a cranking motor 16. The
cranking motor 16 can take any suitable form, and it is
conventionally an electrical motor that is powered during cranking
conditions by current from a storage battery 18 such as a
conventional lead acid battery. Current from the battery 18 is
switched to the cranking motor 16 via a switch such as a
conventional solenoid switch 20. The solenoid switch 20 is
controlled by a conventional starter switch 22.
[0010] All of the elements 10 through 22 described above may be
entirely conventional, and are well-known to those skilled in the
art. The present invention is well adapted for use with the widest
variety of alternative embodiments of these elements.
[0011] In addition to the conventional electrical system described
above, the vehicle 10 also includes a supplemental electrical
system including a capacitor 30. The capacitor 30 is preferably a
double layer capacitor of the type known in the art has an
electrochemical capacitor. Suitable capacitors may be obtained from
KBI, Lake in the Hills, IL under the trade name KAPower. For
example, in one alternative the capacitor 30 has a capacitance of
1000 farads, a stored energy capacity of 60 kilojoules, an internal
resistance at -30 degrees Celsius of 0.004 ohms, and a maximum
storage capacity of 17 kilowatts. In general, the capacitor should
have a capacitance greater than 320 farads, and an internal
resistance at 20.degree. C. that is preferably less than 0.008
ohms, more preferably less than 0.006 ohms, and most preferably
less than 0.003 ohms. The energy storage capacity is preferably
greater than 15 kJ. Such capacitors provide the advantage that they
deliver high currents at low temperatures and relatively low
voltages because of their unusually low internal resistance.
Further information about suitable capacitors for use in the system
of FIG. 1 can be found in publications of ESMA, Troitsk, Moscow
region, Russia and on the Internet at www.esma-cap.com.
[0012] The capacitor 30 includes a negative terminal that is
connected to system ground, and a positive terminal that is
connected to the electrical system of the vehicle via a first
signal path 32 and a second signal path 36. The first signal path
32 is used for charging the capacitor 30, and it includes two
circuits 34, 42. The first circuit 34 operates to prevent excessive
discharging of the capacitor 30. The circuit 34 can take many
forms. In one example, the circuit 34 includes a low voltage
disconnect circuit that disconnects the capacitor 30 from the
electrical system of the vehicle when the voltage on the first path
32 falls below a preselected level. For example, the circuit 34 may
open the first path 32 when the voltage on the first path 32 falls
below 11.8 volts. Higher or lower voltages may be used. In this
example, the capacitor 30 receives charging currents from the
generator 14 via the first path 32, and the capacitor 30 supplies
current to various loads in the electrical system of the vehicle
until the voltage in the first path 32 falls below the selected
level. A suitable device for performing this function can be
obtained from Sure Power Industries, Inc., Tualatin, Oregon as
model number 13600.
[0013] In another example, the circuit 34 may simply include a
suitably sized diode oriented to pass charging currents from the
generator 14 to the capacitor 30 while blocking discharging
currents from the capacitor 30 via the first path 32. Many other
alternatives are possible, as long as the first circuit 34 achieves
the desired function of protecting the capacitor 30 against
excessive discharge, thereby ensuring that the capacitor 30
maintains an adequate charge to start the engine 12.
[0014] The circuit 42 is included in the first path 32 to optimize
the charging voltage applied to the capacitor 30 for the presently
prevailing temperature. The circuit 42 increases the charging
voltage applied to the capacitor 30 at low temperatures, when
engine starting requirements are increased and conventional battery
performance is decreased. FIG. 2 shows one example of a suitable
voltage profile as a function of temperature. Note that the
temperature is preferably the temperature of the capacitor 30, and
the charging voltage applied to the capacitor 30 is greater below a
selected temperature (such as zero degrees Celsius) than it is at a
higher temperature (such as +30 degrees Celsius). The profile of
FIG. 2 is intended by way of example and many other profiles can be
used, including profiles that are continuous in slope as well as
stepwise profiles.
[0015] The circuit 42 can take many forms. For example, a
conventional battery optimizer can be used, such as that supplied
by Purkey's Fleet Electric, Inc., Rogers, Ariz. Such battery
optimizers control the voltage applied to the voltage sense input
of the generator 14, thereby altering the regulated voltage
generated by the generator 14. Alternately, the circuit 42 can
include a DC to DC converter that converts a voltage generated by
the generator 14 to the desired charging voltage, which can vary as
a function of temperature in accordance with the profiles discussed
above.
[0016] The second path 36 connects the capacitor 30 to the cranking
motor 16 via a high amperage switch 38. The switch 38 may for
example be a MOSFET switch such as that sold by IntraUSA under the
trade name Intra switch.
[0017] The switch 38 is controlled by a switch controller 40 that
is in turn coupled with the starter switch 22 of the vehicle 10.
The controller 40 holds the switch 38 in an open circuit condition
except when the starter switch 22 commands engine cranking, at
which time the switch 38 is closed. Thus, the controller 40 causes
the switch 38 to be closed during cranking conditions and opened
during non-cranking conditions. The controller 40 can take many
forms, including conventional analog and digital circuits.
Microprocessors can also readily be adapted to perform the
functions of the controller 40. It is not essential in all cases
that the switch 38 be in an open circuit condition at all times
other than when the engine 12 is being cranked. For example, the
controller 40 may allow the switch 38 to remain in the closed
circuit condition after engine cranking has terminated, as long as
the voltage supplied by the capacitor 30 does not fall below a
desired level, one that which the capacitor 30 stores sufficient
power to start the engine 12 reliably. In this case, the first path
32 and the circuit 34 may be eliminated, and the circuit 42 may be
placed in the second path 36.
[0018] The system of FIG. 1 provides a number of important
advantages. First, the supplemental electrical system including the
capacitor 30 provides adequate current for reliable engine
starting, even if the battery 18 is substantially discharged by
auxiliary loads when the engine 12 is not running. If desired, the
supplemental electrical system including the capacitor 30 may be
made invisible to the user of the vehicle. That is, the vehicle
operates in the normal way, but the starting advantages provided by
the capacitor 30 are obtained without any intervention on the part
of the user.
[0019] Additionally, the capacitor 30 provides the advantage that
it can be implemented with an extremely long life device that can
be charged and discharged many times without reducing its
efficiency in supplying adequate cranking current.
[0020] As used herein, the term "coupled with" is intended broadly
to encompass direct and indirect coupling. Thus, first and second
elements are said to be coupled with one another whether or not a
third, unnamed, element is interposed therebetween. For example,
two elements may be coupled with one another by means of a
switch.
[0021] The term "battery" is intended broadly to encompass a set of
batteries including one or more batteries.
[0022] The term "set" means one or more.
[0023] The term "path" is intended broadly to include one or more
elements that cooperate to provide electrical interconnection, at
least at some times. Thus, a path may include one or more switches
or other circuit elements in series with one or more
conductors.
[0024] Of course, many alternatives are possible. The functions of
the elements of 34, 38, 40, 42 may if desired all be integrated
into a single device. Is anticipated that such integration may
simplify packaging requirements and reduce manufacturing costs. Any
appropriate technology can be used implement the functions
described above.
[0025] The foregoing description has discussed only a few of the
many forms that this invention can take. For this reason, this
detailed description is intended by way of illustration, not
limitation. It is only the claims, including all equivalents, that
are intended to define the scope of this invention.
* * * * *
References