U.S. patent application number 10/132378 was filed with the patent office on 2003-10-30 for pollution reduction by pulsed engine compression braking.
Invention is credited to Sutton, Loran.
Application Number | 20030200744 10/132378 |
Document ID | / |
Family ID | 29248749 |
Filed Date | 2003-10-30 |
United States Patent
Application |
20030200744 |
Kind Code |
A1 |
Sutton, Loran |
October 30, 2003 |
Pollution reduction by pulsed engine compression braking
Abstract
An apparatus and method for reducing pollutants in engine
exhaust through the use of pulsed engine compression braking. The
apparatus includes a controller, a number of engine sensors
connected to the controller, and connections from the controller to
the exhaust valves. Bases on data from the engine sensors, the
invention opens the exhaust valves during either the compression
stroke, the exhaust stroke, or both. Hot fuel mixture or hot gases
are then injected into the exhaust manifold, where they burn
pollutants. Optionally, pressurized air can be injected into the
exhaust manifold to assist in burning pollutants.
Inventors: |
Sutton, Loran; (East Peoria,
IL) |
Correspondence
Address: |
BRIGGS AND MORGAN, P.A.
2400 IDS CENTER
MINNEAPOLIS
MN
55402
US
|
Family ID: |
29248749 |
Appl. No.: |
10/132378 |
Filed: |
April 26, 2002 |
Current U.S.
Class: |
60/289 ; 60/304;
60/305; 60/306 |
Current CPC
Class: |
F02D 2250/18 20130101;
F02D 41/0002 20130101; Y02T 10/40 20130101; F02D 2200/0414
20130101; F02D 2200/703 20130101; F01L 2800/00 20130101; F02D
2041/001 20130101; F02D 2200/0406 20130101; F02D 41/1446 20130101;
F02D 41/0007 20130101; F01N 3/32 20130101; F02D 2200/602 20130101;
F01L 2001/0535 20130101; F01L 2820/041 20130101; F02D 2200/0606
20130101; F02D 2200/501 20130101; Y02T 10/42 20130101; F01N 2430/10
20130101; F01L 13/065 20130101 |
Class at
Publication: |
60/289 ; 60/304;
60/305; 60/306 |
International
Class: |
F01N 003/00; F01N
003/10 |
Claims
What is claimed:
1. Apparatus for reducing pollutants in engine exhaust through the
use of pulsed engine compression braking, the engine having
cylinders, a crankshaft, and an exhaust manifold and a plurality of
exhaust valves connected to the exhaust manifold, the engine
operating in a cycle that includes a compression stroke and an
exhaust stroke, the apparatus comprising: (a) a controller; (b) a
plurality of sensors connected to the controller, the sensors
detecting a plurality of engine conditions; and (c) connections
from the controller to the exhaust valves wherein the controller
reads data from the sensors and controls the opening of the exhaust
valves based on piston position wherein hot gases from the
cylinders are injected into the exhaust manifold to burn pollutants
therein.
2. The apparatus of claim 1, wherein the controller opens the
exhaust valves when the piston is at a position before top dead
center on the compression stroke.
3. The apparatus of claim 1, wherein the controller opens the
exhaust valves when the piston is at a position before top dead
center on the exhaust stroke.
4. The apparatus of claim 1, wherein the controller opens the
exhaust valves when the piston is at a position before top dead
center on the compression stroke and at a position before top dead
center on the exhaust stroke.
5. The apparatus of claim 1, further comprising an air pump
connected to the exhaust manifold, the air pump controlled by the
controller and adapted to inject pressurized air into the exhaust
manifold to increase the temperature of pollutants burning in the
exhaust manifold.
6. The apparatus of claim 1, wherein the sensors are selected from
the group consisting of: exhaust temperature sensor, engine rpm
sensor, vehicle speed sensor, accelerator pedal position sensor,
engine coolant temperature sensor, engine intake manifold
temperature sensor, engine fuel temperature sensor, engine boost
pressure sensor, engine atmospheric pressure sensor, crankshaft
position/speed/timing sensor, and camshaft position/speed/timing
sensor.
7. Apparatus for reducing pollutants in engine exhaust through the
use of pulsed engine compression braking, the engine having
cylinders, a piston, and an exhaust manifold and a plurality of
exhaust valves connected to the exhaust manifold, the engine
operating in a cycle that includes a compression stroke and an
exhaust stroke, the apparatus comprising: (a) a controller; (b) a
plurality of sensors connected to the controller, the sensors
detecting a plurality of engine conditions; (c) connections from
the controller to the exhaust valves; and (d) an air pump connected
to the exhaust manifold and controlled by the controller to inject
pressurized air into the exhaust manifold thereby increasing the
temperature of pollutants burning in the exhaust manifold; wherein
the controller reads data from the sensors and controls the opening
of the exhaust valves based on piston position; wherein hot gases
from the cylinders are injected into the exhaust manifold to burn
pollutants therein.
8. The apparatus of claim 7, wherein the controller opens the
exhaust valves when the piston is at a position before top dead
center on the compression stroke.
9. The apparatus of claim 7, wherein the controller opens the
exhaust valves when the piston is at a position before top dead
center on the exhaust stroke.
10. The apparatus of claim 7, wherein the controller opens the
exhaust valves when the piston is at a position before top dead
center on the compression stroke and at a position before top dead
center on the exhaust stroke.
11. A method for reducing pollutants in engine exhaust through the
use of pulsed engine compression braking, the engine having
cylinders, a piston, and an exhaust manifold and a plurality of
exhaust valves connected to the exhaust manifold, the engine
operating in a cycle that includes a compression stroke and an
exhaust stroke, the method comprising the steps of: (a) sensing a
plurality of engine conditions; (b) opening the exhaust valves
based on the sensed engine conditions, the opening of the exhaust
valves causing engine compression braking; (c) injecting hot gases
from the cylinders into the exhaust manifold through the exhaust
valves; and (d) using the hot gases to burn pollutants in the
exhaust manifold.
12. The method of claim 11, wherein the step of opening the exhaust
valves occurs when the piston is at a position before top dead
center on the compression stroke.
13. The method of claim 11, wherein the step of opening the exhaust
valves occurs when the piston is at a position before top dead
center on the exhaust stroke.
14. The method of claim 11, wherein the step of opening the exhaust
valves occurs when the piston is at a position before top dead
center on the compression stroke and when the piston is at a
position before top dead center on the exhaust stroke.
15. The method of claim 11, further comprising the steps of
injecting pressurized air into the exhaust manifold and increasing
the temperature of burning pollutants in the exhaust manifold due
to the injected pressurized air.
16. The method of claim 11, wherein the step of sensing a plurality
of engine conditions includes sensing engine conditions selected
from the group consisting of: exhaust temperature, engine rpm,
vehicle speed, accelerator pedal position, engine coolant
temperature, engine intake manifold temperature, engine fuel
temperature, engine boost pressure, engine atmospheric pressure,
crankshaft position/speed/timing, and camshaft
position/speed/timing.
17. A method for reducing pollutants in engine exhaust through the
use of pulsed engine compression braking, the engine having
cylinders, a piston, and an exhaust manifold and a plurality of
exhaust valves connected to the exhaust manifold, the engine
operating in a cycle that includes a compression stroke and an
exhaust stroke, the method comprising the steps of: (a) sensing a
plurality of engine conditions; (b) opening the exhaust valves
based on the sensed engine conditions, the opening of the exhaust
valves causing engine compression braking; (c) injecting hot gases
from the cylinders into the exhaust manifold through the exhaust
valves; (d) injecting pressurized air into the exhaust manifold;
and (e) using the hot gases and pressurized air to bum pollutants
in the exhaust manifold.
18. The method of claim 17, wherein the step of opening the exhaust
valves occurs when the piston is at a position before top dead
center on the compression stroke.
19. The method of claim 17, wherein the step of opening the exhaust
valves occurs when the piston is at a position before top dead
center on the exhaust stroke.
20. The method of claim 17, wherein the step of opening the exhaust
valves occurs when the piston is at a position before top dead
center on the compression stroke and when the piston is at a
position before top dead center on the exhaust stroke.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an apparatus and method for
reducing pollutants in the exhaust from an internal combustion
engine through the use of pulsed engine compression braking.
[0002] Compression release engine brakes for internal combustion
engines are well known as shown, for example, in U.S. Pat. Nos.
5,410,882; 5,540,201; 5,740,771; 5,813,231; 5,894,731; and
6,148,793. The purpose of such brakes is to convert the associated
engine from a power source to a power sink when braking is desired.
Such power sinking may be helpful to assist the wheel brakes of a
vehicle propelled by the engine, thereby prolonging the life of the
wheel brakes and increasing the safety of operation of the vehicle.
When engine braking is desired, the flow of fuel to the engine is
cut off and the engine brake is turned on. Turning on the engine
brake causes it to open at least one exhaust valve in at least one
engine cylinder each time the piston in that cylinder nears top
dead center of its compression stroke. This releases to the exhaust
manifold of the engine the gas that was compressed in the cylinder
and prevents the work done in compressing that gas from being
recovered in the subsequent "power" stroke of the piston. The
engine therefore dissipates the work of compressing the gas thus
exhausted, and that dissipated work brakes the engine and the
associated vehicle. In effect, the engine brake temporarily
converts the engine to a gas compressor in order to make the engine
absorb work or energy.
[0003] Other methods of achieving compression braking utilize
various devices to open the exhaust valve at points in the engine
cycle other than top dead center on the compression stroke. For
example, U.S. Pat. No. 5,540,201 discloses opening the exhaust
valve near bottom dead center on the intake stroke, allowing
exhaust gases from the exhaust manifold to flow into the cylinder
and thus boost the pressure in the cylinder just prior to
compression. This boosting results in a pressure increase which in
turn causes the engine to expend more work in compressing the gas,
causing additional engine braking.
[0004] Another problem commonly associated with internal combustion
engines for automobiles is that these engines emit pollutants into
the atmosphere. It is well known that internal combustion engines
operate with the greatest fuel efficiency and the most desirable
operating characteristics when the engine has reached its optimum
operating temperature. It is also well known that the typical
internal combustion engine has greater undesirable emissions of
unburned fuel when the engine is operating below its optimum
operating temperature. A variety of methods have been used to
enhance engine warm-up, among them being various exhaust
restriction devices that raise engine operating temperature by
increasing the backpressure within the exhaust manifold, causing
the engine to work harder and thus increase its operating
temperature. An example of such an apparatus is disclosed in U.S.
Pat. No. 6,092,371. Placing the engine under load by increasing
exhaust manifold pressure is also desirable because it raises
exhaust temperature, which promotes combustion and decreases carbon
build up, as disclosed in U.S. Pat. No. 6,109,027. Other U.S.
Patents that disclose exhaust restrictive devices are: U.S. Pat.
Nos. 6,209,324; and 6,308,517.
[0005] Another method to reduce pollution from the engine is
exhaust gas re-circulation, which re-burns the mixture in the
engine to clean the pollutants.
[0006] However, none of these patents has recognized that
pollutants from internal combustion engines can be reduced by using
pulsed engine compression braking to dump hot or ignited exhaust
gases from the engine cylinders into the exhaust manifold to burn
pollutants.
[0007] There is a need for an apparatus and method to reduce
pollution from internal combustion engines by using compression
engine braking that is pulsed in response to various engine
conditions. The apparatus and method should include a combination
of randomly selected compression braking on the compression stroke
and compression braking on the exhaust stroke. There should be a
mechanism for introducing additional air into the exhaust manifold
to create a higher temperature, resulting in cleaner emissions.
SUMMARY OF THE INVENTION
[0008] Apparatus for reducing pollutants in engine exhaust through
the use of pulsed engine compression braking, the engine having
cylinders, a crankshaft, and an exhaust manifold and a plurality of
exhaust valves connected to the exhaust manifold, the engine
operating in a cycle that includes a compression stroke and an
exhaust stroke, the apparatus comprising:
[0009] (a) a controller;
[0010] (b) a plurality of sensors connected to the controller, the
sensors detecting a plurality of engine conditions; and
[0011] (c) connections from the controller to the exhaust
valves
[0012] wherein the controller reads data from the sensors and
controls the opening of the exhaust valves based on piston
position
[0013] wherein hot gases from the cylinders are injected into the
exhaust manifold to bum pollutants therein.
[0014] A method for reducing pollutants in engine exhaust through
the use of pulsed engine compression braking, the engine having
cylinders, a piston, and an exhaust manifold and a plurality of
exhaust valves connected to the exhaust manifold, the engine
operating in a cycle that includes a compression stroke and an
exhaust stroke, the method comprising the steps of:
[0015] (a) sensing a plurality of engine conditions;
[0016] (b) opening the exhaust valves based on the sensed engine
conditions, the opening of the exhaust valves causing engine
compression braking;
[0017] (c) injecting hot gases from the cylinders into the exhaust
manifold through the exhaust valves;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] The operating environment of the present invention is shown
in U.S. Pat. No. 5,540,201, herein incorporated by reference.
[0019] FIG. 1 from U.S. Pat. No. 5,540,201 shows an internal
combustion engine 30, which may be of the four-cycle, compression
ignition type. The invention may also be used with a diesel engine
or any engine that includes a compression stroke and an exhaust
stroke.
[0020] The engine repetitively undergoes intake, compression,
combustion and exhaust cycles during operation.
[0021] The engine 30 includes a block 32 within which is formed a
plurality of combustion chambers or cylinders 34, each of which
includes an associated piston 36 therein. Intake valves 38 and
exhaust valves 40 are carried in a head 41 bolted to the block 32
and operated to control the admittance and expulsion of fuel and
gases into and out of each cylinder 34. A crankshaft 42 is coupled
to and rotated by the pistons 36 via connecting rods 44 and a
camshaft 46 is coupled to and rotates with the crankshaft 42 in
synchronism therewith. The camshaft in turn drives the intake
valves 38 and exhaust valves 40 through rocker arms 54, 55.
[0022] As disclosed in U.S. Pat. No. 5,740,771, herein incorporated
by reference, the typical internal combustion engine operates with
a four stroke cycle known as the Otto-cycle. During the first
stroke, the intake valve 38 is in the open position and the piston
36 moves from the top dead center position (shown on the left in
FIG. 1 of the present application) toward the bottom of the
cylinder 34 while the mixture of fuel and air enters the cylinder
34 through the intake valve 38. This stroke defines an intake
stroke. The second stroke of the Otto-cycle is known as the
compression stroke. During the compression stroke the piston 36
rises in the cylinder 34 with both the intake 38 and exhaust 40
valves in the closed position, compressing the mixture of fuel and
air in the cylinder 34. Then, during the combustion stroke,
combustion of the mixture takes place forcing the piston 36 back
down toward the bottom of the cylinder 34 while the intake valve 38
and the exhaust valve 40 are in the closed position. Finally,
during an exhaust stroke, the exhaust valve 40 opens and the piston
36 rises in the cylinder 34 forcing exhaust out of the cylinder 34
into the exhaust manifold 60.
[0023] The apparatus of the present invention is shown in FIG. 2 as
reference numeral 110.
[0024] The apparatus 110 comprises a controller 112; a plurality of
sensors 114 connected to the controller 112; and connections 116
from the controller to the exhaust valves 40.
[0025] The sensors detect a plurality of engine conditions. The
controller reads data from the sensors 114 and controls the opening
of the exhaust valves 40 based on the position of the piston
36.
[0026] In one embodiment, the controller opens the exhaust valves
40 when the piston reaches a position slightly before top dead
center (TDC) on the compression stroke. Opening the exhaust valves
at this point in the Otto Cycle results in engine compression
braking, as described above. In addition, however, the fuel mixture
has been heated by compression. When the exhaust valves 40 are
opened, the hot fuel mixture is injected into the exhaust manifold
60. The hot fuel mixture may then ignite and burn any pollutants
that are in the exhaust manifold.
[0027] In a second embodiment, the controller opens the exhaust
valves 40 when the piston reaches a position slightly before TDC on
the exhaust stroke. That is, unlike the normal Otto Cycle
operation, the exhaust valves remain closed throughout most of the
exhaust stroke. This causes heating of the exhaust gases by
compression. When the exhaust valves are opened, the hot gases are
injected into the exhaust manifold 60, where they may assist in
burning any pollutants that are in the exhaust manifold. Also, any
unburnt fuel in the cylinder 34 may ignite in the exhaust manifold
and further assist in burning the pollutants.
[0028] In a third embodiment, the controller opens the exhaust
valves 40 both slightly before TDC on the compression stroke and
slightly before TDC on the exhaust stroke. This embodiment combines
the features of the first two embodiments.
[0029] The controller uses logic and the data read from the sensors
114 to determine how much before TDC to open the exhaust valves,
how frequently to open the exhaust valves, and when to open the
exhaust valves on the compression stroke or on the exhaust
stroke.
[0030] The sensors that the controller may use include, but are not
limited to: an exhaust temperature sensor (both upstream and
downstream); an engine rpm sensor; a vehicle speed sensor; an
accelerator pedal position sensor; an engine coolant temperature
sensor; an engine fuel temperature sensor; an engine boost pressure
sensor; an engine atmospheric pressure sensor; a crankshaft
position/speed/timing sensor; and a camshaft position/speed/timing
sensor. Data from many of these sensors is available from the
engine control module (ECM) data line with the use of a decoder.
However, the information that is available from the ECM varies from
manufacturer to manufacturer. Therefore, additional sensors may be
necessary.
[0031] A fourth embodiment of the invention uses an air pump 118 to
inject pressurized air into the exhaust manifold 60. This will
cause the mixture to bum more completely, reducing the
pollutants.
[0032] A flow chart of the method of the present invention is shown
in FIG. 3.
[0033] In the first step 200, the controller 112 receives
information on engine conditions from the sensors 114. If the
piston is on the compression stroke 300, the controller 112
determines 310, from the information received from the sensors,
whether it is time to open the exhaust valves. If so, the
controller sends a signal via connections 116 to the exhaust valves
40 to open (step 320). The controller then performs similar
processing if the piston is on the exhaust stroke (400, 410) and
opens the exhaust valves if appropriate (320). If the method is to
include a step of injecting pressurized air into the exhaust
manifold, the controller determines (500) if it is time to do,
based on the data received from the sensors 114. If so, it injects
air (510).
[0034] The present invention may be embodied in other specific
forms without departing from the spirit or essential attributes
thereof, and it is therefore desired that the present embodiment be
considered in all respects as illustrative and not restrictive,
reference being made to the appended claims rather than to the
foregoing description to indicate the scope of the invention.
* * * * *