U.S. patent number 3,916,622 [Application Number 05/475,296] was granted by the patent office on 1975-11-04 for combustion engine with at least one exhaust gas cleaning arrangement.
This patent grant is currently assigned to Volkswagenwerk Aktiengesellschaft. Invention is credited to Reinhard Gospodar.
United States Patent |
3,916,622 |
Gospodar |
November 4, 1975 |
Combustion engine with at least one exhaust gas cleaning
arrangement
Abstract
In a motor vehicle, a combustion engine having a plurality of
combustion spaces, fuel and combustion air supplying devices,
exhaust conduits for the individual combustion spaces for
delivering the exhaust gas from the combustion spaces, an exhaust
gas cleaning arrangement connected in a common branch of the
individual exhaust gas conduits, a sensor coupled to the combustion
spaces for sensing characteristic conditions of the individual
spaces or cylinders, and means responsive to the individual sensed
conditions when the individual condition of a cylinder deviates
from a predetermined characteristic and developing a signal when
such deviation occurs, and means responsive to such signal and
controlling the fuel flow to the individual cylinder when the
deviation occurs.
Inventors: |
Gospodar; Reinhard (Wolfsburg,
DT) |
Assignee: |
Volkswagenwerk
Aktiengesellschaft (Wolfsburg, DT)
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Family
ID: |
27183686 |
Appl.
No.: |
05/475,296 |
Filed: |
May 31, 1974 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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262007 |
Jun 12, 1972 |
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Foreign Application Priority Data
Current U.S.
Class: |
60/277; 123/198D;
374/143; 374/144; 60/285; 123/198DB; 123/198F; 73/114.69 |
Current CPC
Class: |
F02D
41/1443 (20130101); F01N 3/18 (20130101); F01N
3/08 (20130101); Y02A 50/20 (20180101); F02D
2041/389 (20130101); F02D 2700/09 (20130101) |
Current International
Class: |
F01N
3/18 (20060101); F02D 41/14 (20060101); F01N
3/08 (20060101); F02b 075/10 () |
Field of
Search: |
;60/274,277,285
;123/198D,198DB,198F,14MC ;73/115,116,117.3,346,35 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Hart; Douglas
Attorney, Agent or Firm: Marmorek; Ernest F.
Parent Case Text
This is a continuation, of application Ser. No. 262,007, filed June
12, 1972.
Claims
Having thus described the invention, what I claim as new and desire
to be secured by letters Patent, is as follows:
1. A combustion engine comprising a plurality of combustion spaces
or cylinders, fuel and combustion air supplying means, exhaust
conduits for the individual combustion spaces for delivering the
exhaust gas from said combustion spaces, an exhaust gas cleaning
arrangement connected in a common branch of said individual exhaust
gas conduits, sensing means coupled to said combustion spaces for
sensing characteristic conditions of the individual cylinders,
means reponsive to an individual sensed condition when the
individual condition of a cylinder deviates from a predetermined
magnitude and developing a signal when such deviation occurs, means
responsive to said signal for regulating the fuel flow to said
individual cylinder when said deviation occurs, a temperature
sensor means coupled to said exhaust gas cleaning arrangement for
sensing the temperature thereof and for producing a signal when
said temperature of said exhaust gas cleaning means deviates from
said predetermined value, a gate circuit means having a pair of
inputs, the output of said individual sensing means sensing the
condition of the individual cylinder being connected to one of said
inputs of said gate circuit means, the output of said temperature
sensor means coupled to said exhaust gas cleaning arrangement being
coupled to the other one of said input of said gating circuit
means, said gating circuit means passing the output signal of said
temperature sensor means of said exhaust cleaning arrangement when
an output signal is present at said first output thereof, said fuel
supply means comprising operating means, the output of said gating
circuit means being coupled to said operating means for energizing
said operating means for effecting regulation of said fuel supply
to said individual cylinder when the conditions thereof deviate
from a predetermined magnitude.
2. The combination as claimed in claim 1, wherein said combustion
engine comprises a combustion air dosing means for each of said
individual cylinders said combustion air supply means having an
operating means for controlling the positioning of said combustion
air dosing means, the output signal of said gating circuit means
being coupled also to said operating means for said combustion air
dosing means.
3. The combination as claimed in claim 1, wherein said output
signal of said gating circuit means being effective to disconnect
the fuel supply to said individual cylinder means.
4. The combination as claimed in claim 1, wherein said combustion
engine comprises an outside fuel-air mixture means, said fuel-air
mixture means comprising an operating member and a closure member
placed in the supply conduit of said fuel-air mixture, said output
signal of said gating circuit means effecting said operating member
for closing said closure member and thereby effecting regulation of
the fuel-air supply to said individual cylinder.
5. The combination as claimed in claim 2, wherein a comparing
circuit is connected to the output of said individual sensor means
sensing the conditions of said individual cylinders, said comparing
circuit determining when the output of said individual sensor means
deviates from a predetermined magnitude representing the normal
operation of an individual cylinder.
6. The combination as claimed in claim 1, wherein said sensor means
are temperature sensor means for sensing the temperature of the
individual cylinders.
7. The combination as claimed in claim 1, wherein said sensor means
are pressure sensing means for sensing the pressure in the
individual cylinders.
8. The combination as claimed in claim 1, wherein said sensor means
are temperature sensors for sensing the temperature of the exhaust
from the individual cylinders.
9. A combustion engine comprising a plurality of combustion spaces
or cylinders, fuel and combustion air supplying means, exhaust
conduits for the individual combustion spaces for delivering the
exhaust gas from said combustion spaces, an exhaust gas cleaning
arrangement connected in a common branch of said individual exhaust
gas conduits, sensing means coupled to said combustion spaces for
sensing characteristic conditions of the individual cylinders, and
means responsive to an individual sensed condition when the
individual condition of a cylinder deviates from a predetermined
magnitude so as to lead to overheating of said exhaust gas cleaning
arrangement and developing a signal when such deviation occurs, and
means responsive to said signal and reducing the fuel flow only to
said individual cylinder when said deviation occurs and wherein a
temperature sensor means is coupled to said exhaust gas cleaning
arrangement for sensing the temperature thereof and for producing a
signal when said temperature of said exhaust gas cleaning means
deviates from said predetermined value, a gate circuit means having
a pair of inputs, the output of said individual sensing means
sensing the condition of the individual cylinder is being connected
to one of said inputs of said gate circuit means, the output of
said temperature sensor means coupled to said exhaust gas cleaning
arrangement being coupled to the other one of said inputs of said
gating circuit means, said gating circuit means passing the output
signal of said temperature sensor means of said exhaust cleaning
arrangement when an output signal is present at said first output
thereof, said fuel supply means comprising operating means, the
output of said gating circuit means being coupled to said operating
means for energizing said operating means for effecting regulation
of said fuel supply to said individual cylinder when the conditions
thereof deviate from a predetermined magnitude.
10. The combination as claimed in claim 9, wherein said combustion
engine comprises a combustion air dosing means for each of said
individual cylinders, said combustion air supply means having an
operating means for controlling the positioning of said individual
cylinders, said combustion air supply means having an operating
means for controlling the positioning of said combustion air dosing
means, the output signal of said gating circuit means being coupled
also to said operating means for said combustion air dosing
means.
11. The combination as claimed in claim 9, wherein said output
signal of said gating circuit means is effective to disconnect the
fuel supply to said individual cylinder means.
12. The combination as claimed in claim 9, wherein said combustion
engine comprises an outside fuel-air mixture means, said fuel-air
mixture means comprising a supply conduit an operating member and a
closure member placed in the supply conduit of said fuel-air
mixture, said output signal of said gating circuit means effecting
said operating member for closing said closure member and thereby
preventing fuel-air supply to said individual cylinder.
13. The combination as claimed in claim 9, wherein a comparing
circuit is connected to the output of said individual sensor means
sensing the conditions of said individual cylinders, said comparing
circuit determining when the output of said individual sensor means
deviates from a predetermined magnitude representing the normal
operation of an individual cylinder.
14. The combination as claimed in claim 9, wherein said sensor
means are temperature sensor means for sensing the temperature of
the individual cylinders.
15. The combination as claimed in claim 9, wherein said sensor
means are pressure sensing means for sensing the pressure in the
individual cylinders.
16. The combination as claimed in claim 9, wherein said sensor
means are temperature sensors for sensing the temperature of the
exhaust from the individual cylinders.
17. A combustion engine comprising a plurality of groups of
combustion spaces or cylinders, fuel and combustion air supplying
means, a common exhaust conduit for each of said group of
combustion spaces for delivering the exhaust gas from said
combustion spaces, an exhaust gas cleaning arrangement connected to
said common exhaust gas conduits, sensing means coupled to said
combustion spaces for sensing characteristic conditions of the
individual cylinders, and means responsive to an individual sensed
condition when the individual condition of a cylinder deviates from
a predetermined magnitude so as to lead to overheating of said
exhaust gas cleaning arrangement, and developing a signal when such
deviation occurs, and means responsive to said signal and reducing
the fuel flow only to said individual cylinder when said deviation
occurs, there being further included a temperature sensor means
coupled to said exhaust gas cleaning arrangement for sensing the
temperature thereof and for producing a signal when said
temperature of said exhaust gas cleaning means deviates from said
predetermined value, a gate circuit means having a pair of inputs,
the output of said individual sensing means sensing the condition
of the individual cylinder being connected to one of said inputs of
said gate circuit means, the output of said temperature sensor
means coupled to said exhaust gas cleaning arrangement being
coupled to the other one of said inputs of said gating circuit
means, said gating circuit means passing the output signal of said
temperature sensor means of said exhaust cleaning arrangement when
an output signal is present at said first output thereof, said fuel
supply means comprising operating means, the output of said gating
circuit means being coupled to said operating means for energizing
said operating means for effecting regulation of said fuel supply
to said individual cylinder when the conditions thereof deviate
from a predetermined magnitude.
18. The combination as claimed in claim 17, wherein said combustion
engine comprises an outside fuel-air mixture means, said fuel-air
mixture means comprising a supply conduit an operating member and a
closure member placed in the supply conduit of said fuel-air
mixture, said output signal of said gating circuit means effecting
said operating member for closing said closure member and thereby
preventing fuel-air supply to said individual cylinder.
19. The combination as claimed in claim 17, wherein a comparing
circuit is connected to the output of said individual sensor means
sensing the conditions of said individual cylinders, said comparing
circuit determining when the output of said individual sensor means
deviates from a predetermined magnitude representing the normal
operation of an individual cylinder.
20. A combustion engine comprising a plurality of groups of
combustion spaces or cylinders, fuel and combustion air supplying
means, a common exhaust conduit for each of said groups of
combustion spaces for delivering the exhaust gas from said
combustion spaces, and exhaust gas cleaning arrangement connected
to said common exhaust gas conduits, sensing means coupled to said
combustion spaces for sensing characteristic conditions of the
individual cylinders, and means responsive to an individual sensed
condition when the individual condition of a cylinder deviates from
a predetermined magnitude so as to lead to overheating of said
exhaust gas cleaning arrangement, and developing a signal when such
deviation occurs, and means responsive to said signal for reducing
the fuel flow to said cylinder group in which one of said cylinders
deviates.
21. The combination as claimed in claim 20, wherein a temperature
sensor means is coupled to said exhaust gas cleaning arrangement
for sensing the temperature thereof and for producing a signal when
said temperature of said exhaust gas cleaning means deviates from
said predetermined value, a gate circuit means having a pair of
inputs, the output of said individual sensing means sensing the
condition of the individual cylinder being connected to one of said
input of said gate circuit means, the output of said temperature
sensor means coupled to said exhaust gas cleaning arrangement being
coupled to the other one of said inputs of said gating circuit
means, said gating circuit means passing the output signal of said
temperature sensor means of said exhaust cleaning arrangement when
an output signal is present at said first output thereof, said fuel
supply means comprising operating means, the output of said gating
circuit means being coupled to said operating means for energizing
said operating means for effecting regulation of said fuel supply
to said cylinder group when the condition of any cylinder therein
deviates from a predetermined magnitude.
22. The combination as claimed in claim 21, wherein said combustion
engine comprises an outside fuel-air mixture means, said fuel-air
mixture means comprising a supply conduit an operating member and a
closure member placed in the supply conduit of said fuel-air
mixture, said output signal of said gating circuit means effecting
said operating member for closing said closure member and thereby
effecting regulation of the fuel-air supply to said cylinder group
that includes said deviating cylinder.
23. The combination as claimed in claim 22, wherein a comparing
circuit is connected to the output of said individual sensor means
sensing the conditions of said individual cylinders, said comparing
circuit determining when the output of said individual sensor means
deviates from a predetermined magnitude representing the normal
operation of an individual cylinder.
24. A combustion engine comprising a plurality of combustion spaces
or cylinders, fuel and combustion air supplying means, exhaust
conduits for the individual combustion spaces for delivering the
exhaust gas from said combustion spaces, an exhaust gas cleaning
arrangement connected in a common branch of said individual exhaust
gas conduits, pressure sensing means coupled to said combustion
spaces for sensing the pressure of the individual cylinders, and
means responsive to an individual sensed condition when the
individual condition of a cylinder deviates from a predetermined
magnitude so as to lead to overheating of said exhaust gas cleaning
arrangement and developing a signal when such deviation occurs, and
means responsive to said signal and reducing the fuel flow only to
said individual cylinder when said deviation occurs.
25. A combustion engine comprising a plurality of groups of
combustion spaces or cylinders, fuel and combustion air supplying
means, a common exhaust conduit for each said group of combustion
spaces for delivering the exhaust gas from said combustion spaces,
an exhaust gas cleaning arrangement connected to said common
exhaust gas conduits, sensing means coupled to said combustion
spaces for sensing characteristic conditions of the individual
cylinders, and means responsive to an individual sensed condition
when the individual condition of a cylinder deviates from a
predetermined magnitude so as to lead to overheating of said
exhaust gas cleaning arrangement, and developing a signal when such
deviation occurs, and means responsive to said signal and reducing
the fuel flow only to said individual cylinder when said deviation
occurs and wherein said combustion engine comprises an outside
fuel-air mixture means including a supply conduit an operating
member and a closure member placed in the supply conduit of said
fuel-air mixture, said signal effecting said operating member for
closing said closure member and thereby effecting regulation of the
fuel-air supply to said individual cylinder.
26. A combustion engine comprising a plurality of groups of
combustion spaces or cylinders, fuel and combustion air supplying
means, a common exhaust conduit for each said group of combustion
spaces for delivering the exhaust gas from said combustion spaces,
an exhaust gas cleaning arrangement connected to said common
exhaust gas conduits, sensing means coupled to said combustion
spaces for sensing characteristic conditions of the individual
cylinders, and means responsive to an individual sensed condition
when the individual condition of a cylinder deviates from a
predetermined magnitude so as to lead to overheating of said
exhaust gas cleaning arrangement, and developing a signal when such
deviation occurs, and means responsive to said signal for reducing
the fuel flow to said cylinder group in which one of said cylinders
deviates, said combustion engine comprising an outside fuel-air
mixture means including a supply conduit an operating member and a
closure member placed in the supply conduit of said fuel-air
mixture, said signal effecting said operating member for closing
said closure member and thereby effecting regulation of the
fuel-air supply to said cylinder group that includes said deviating
cylinder.
27. A combustion engine comprising a plurality of combustion spaces
or cylinders, fuel and combustion air supplying means, exhaust
conduits for the individual combustion spaces for delivering the
exhaust gas from said combustion spaces, an exhaust gas cleaning
arrangement connected in a common branch of said individual exhaust
gas conduits, sensing means coupled to said combustion spaces for
sensing characteristic conditions of the individual cylinders,
wherein a comparing circuit is connected to the outputs of said
individual sensor means for sensing the conditions of said
individual cylinders, said comparing circuit comparing output
signals of said individual sensor means and thereby determining
when the sensed characteristic condition of an individual cylinder
leads to overheating of said exhaust gas cleaning arrangement and
developing a signal when such condition occurs, and means
responsive to said signal for reducing fuel flow only to said
individual cylinder when such condition occurs.
28. A combustion engine comprising a plurality of groups of
combustion spaces or cylinders, fuel and combustion air supplying
means, exhaust conduits for the individual groups of combustion
spaces for delivering the exhaust gas from said combustion spaces,
an exhaust gas cleaning arrangement connected in a common branch of
said individual exhaust gas conduits, sensing means coupled to
parts of said groups for sensing characteristic conditions of the
cylinders of the individual groups, wherein a comparing circuit is
connected to the output of said individual sensor means of said
groups, said comparing circuit comparing output signals of said
individual sensor means of different groups and thereby determining
when the sensed characteristic condition of a cylinder of an
individual group leads to overheating of said exhaust gas cleaning
arrangement and developing a signal when such condition occurs, and
means responsive to said signal for reducing the fuel flow only to
said cylinder group when such condition occurs in one of said
cylinders in said group.
29. A combustion engine comprising a plurality of groups of
combustion spaces or cylinders, fuel and combustion air supplying
means, exhaust conduits for the individual groups of combustion
spaces for delivering the exhaust gas from said combustion spaces,
an exhaust gas cleaning arrangement connected in a common branch of
said individual exhaust gas conduits, sensing means coupled to
parts of said groups for sensing characteristic conditions of the
cylinders of the individual groups, and means responsive to an
individual sensed condition when the individual condition of a
cylinder deviates from a predetermined magnitude so as to lead to
overheating of said exhaust gas cleaning arrangement, and
developing a signal when such deviation occurs, and means reponsive
to said signal for reducing the fuel flow only to said individual
cylinder when said deviation occurs, there being further included a
comparing circuit connected to the output of said individual sensor
means sensing the conditions of said individual cylinders, said
comparing circuit determining when the output of said individual
sensor means deviates from a predetermined magnitude representing
the normal operation of an individual cylinder.
Description
CROSS REFERENCE TO OTHER APPLICATIONS
Reference should be had to the full extent of the co-pending
application of Peter Manderscheid entitled "Combustion Engine With
At Least One Exhaust Gas Cleaning Arrangement" Ser. No. 260,006,
filed June 12, 1972 and to the application of Herbert Heitland
entitled "Converter For Catalythic Exhaust Gas Cleaning" Ser. No.
260,004, filed June 12, 1972 and of the application of Herbert
Heitland and Peter Manderscheid entitled "Arrangement For Exhaust
Gas Cleaning" Ser. No. 262,008, filed June 12, 1972 all being filed
concurrently and being assigned to the same assignee as the present
application.
FIELD AND BACKGROUND OF THE INVENTION
The present invention generally relates to a motor vehicle, and
more particularly it relates to a motor vehicle having a combustion
engine with combustion spaces, such as cylinders, and which further
includes a fuel distribution and measuring system, an exhaust gas
system, an exhaust gas cleaning system having associated therewith
a temperature sensor for producing control signals in the event
very high temperatures are developed within the exhaust gas
cleaning system.
The combustion engine and its associated exhaust gas cleaning
arrangement which is the subject matter of the first aforementioned
co-pending application has its advantage in that its exhaust gas
cleaning arrangement provides a protection against overheating even
in cases when the cause of the overheating resides not in the
defective operation of the cleaning arrangement itself but in the
defectively operating combustion spaces of the engine. Such exhaust
gas cleaning arrangements can operate at their best and attain
their best cleaning efficiency only at relatively high
temperatures, however, they are very sensitive to excessively high
temperatures which can be caused for example by the failure of the
ignition, bad combustion within the combustion spaces or cylinders
or a bad mixture formation within the cylinder. Such defective
cylinders or cylinder group cause the combustion itself to occur
not within the cylinder itself but in the exhaust gas cleaning
arrangement.
The cleaning arrangement according to the aforementioned first
application attacks the problem associated with the overheating of
the exhaust gas cleaning arrangement itself by reducing or in some
circumstances completely disconnecting the fuel supply to the
combustion spaces.
A problem is, however, encountered in connection with the
combustion engines of motor vehicles that during the discontinuing
of the fuel supply to the combustion engine the entire combustion
becomes stalled. In order to eliminate this disadvantage the
structure proposed by the aforementioned first co-pending
application provides that for each combustion space or cylinder or
combustion space group or cylinder group an individual exhaust gas
cleaning arrangement is provided in the individual exhaust gas
conduit of the cylinder or of the group and, each of such cleaning
arrangement has a separate temperature sensor in it the output
signals of which are fed to the fuel dosing and/or air dosing
devices of that particular cylinder or group. In principle such
arrangement leads to an enlargement of the number of the cleaning
arrangements, expecially in the extreme case where each cylinder
has its own cleaning arrangement assigned to it. The proposed
construction, however, assures that only the individual cylinder or
cylinder group is set out of operation the exhaust gas cleaning
arrangement of which developed the excessive temperature.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide a
cleaning arrangement for a combustion engine in a motor vehicle
which eliminates any and all difficulties which might arise with
the structure of the aforementioned first co-pending
application.
It is a more particular object of the present invention to provide
an exhaust gas cleaning arrangement for a combustion engine wherein
in the case of an increased and undesirable temperature within the
exhaust gas cleaning arrangement a reduction or discontinuance of
the fuel supply is undertaken only to an extent that the engine
remains capable of further operation unless all combustion spaces
or cylinders became defective.
It is still a further object of the present invention to reduce the
number of the exhaust gas cleaning arrangements assigned to the
cylinders or cylinder groups in a combustion engine of the above
mentioned type. The present invention provides that the exhaust gas
cleaning arrangement is placed in the common exhaust gas conduit of
several combustion spaces or cylinders or cylinder groups which
also have their individual fuel dosing devices and that on portions
of the cylinders or cylinder groups sensors are provided for
sensing the particular characteristics of the cylinders or cylinder
group themselves and which sensor provides output signals which
together with the control signals of the temperature sensors of the
cleaning arrangement are fed to a gating means coupled with the
associated individual fuel dosing device whereby the control
signals of the cleaning arrangement are supplied only to regulate
the operation of the defective cylinders or cylinder group by
controlling its associated fuel and/or air dosing device.
According to the present invention the sensors monitor only those
cylinders or group of cylinders which are defective and by means of
the output signal of such sensors a gate circuit becomes energized
to which in the present embodiment of the invention the control
signals from the temperature sensor placed into the exhaust gas
cleaning arrangement are also fed. The gate circuit passes the
control signals of the temperature sensor of the cleaning
arrangement only to the dosing devices of those cylinders or of
that particular cylinder which is or are defective and to which the
particular gate circuit belongs.
For the characterizing of the state or rather for the monitoring of
the state of an individual cylinder or of a cylinder group one may
employ the sensors of different types in various regions of the
cylinder arrangement. For example, the sensor can be in the form of
a temperature sensor for sensing the cylinder temperature, one
could also monitor the exhaust gas temperature in the immediate
vicinity of the outlet of the cylinder. Or, for example, pressure
sensors could be used to monitor the cylinder pressure. Furthermore
one could use sensors of various types which, at the same time, are
capable of controlling the fuel dosing devices. A defective
cylinder is characterized by a low cylinder temperature and by a
low exhaust gas temperature and by a low pressure in the cylinder.
Obviously the excessive temperature then will be present in the
exhaust gas cleaner. In some cases one could use sensors to monitor
the components in the exhaust gas of the individual cylinders,
however, such latter design would require a more complicated
arrangement.
The concept of fuel dosing devices is similar to those described in
the first aforementioned co-pending application. It should be still
noted that the individual cylinders or cylinder groups can have
their individual combustion air dosing devices so that the control
signals from the exhaust gas cleaning arrangement would be then fed
to the combustion air dosing device in addition to the fuel dosing
device and limit it or completely disconnect the supply by it, in
the event the associated cylinder or cylinder group is defective.
In a combustion engine having an outer mixture forming arrangement
the above can be constructed in a relatively similar manner by
feeding the control signal from the exhaust gas cleaning
arrangement through the gate circuit to the operating means of a
common closure member controlling a combined fuel-air dosing means,
which can be in the form of a choke valve and placed in the
individual suction conduit of the defective cylinder or defective
cylinder group.
Under the definition of dosing devices within the scope of this
invention, one should understand a device which controls or
determines the fuel or fuel-air mixture supply to an individual
cylinder or to a cylinder group.
At this point it should be noted that the invention is equally
applicable to a combustion engine having a direct or indirect fuel
injection, similarly as mentioned also in connection with the first
aforementioned co-pending application.
Up to this point consideration was given to the case when the
individual cylinder or individual cylinder group were controlled by
the control signals coming from the temperature sensors on the
cleaning arrangement and on the exhaust conduit and fed through an
individual gate circuit associated with that cylinder or cylinder
group. It is also possible that the output signals of the sensors
on the cylinders are fed to a comparing circuit which compares the
output signals coming from the sensors on the different cylinders
or cylinder groups and determines the defective cylinder or
cylinder group and a control signal is passed only to the dosing
device associated with such defective cylinder or cylinder group.
Such comparison of the different cylinders or cylinder groups
resulting from an output signal of the sensors on them which is
monitored as a median value and, the cylinder or cylinder group
which has a monitored signal which deviates from such median value
by a certain magnitude will be characterized as defective.
Inasmuch as the last mentioned variation the output sginals of the
sensors which are sensing the various characteristics of the
individual cylinders or cylinder groups monitor the state of the
cylinders of the combustion engine, therefore, under these
conditions the temperature sensors at the exhaust gas cleaning
arrangement and the gate circuits can be omitted since the output
signals of the comparing circuit represent the control signals
affecting the operation of the dosing devices. While in the
previously discussed principal embodiment of the present invention
a regulation is performed back from the temperature of the cleaning
arrangement, in the last discussed embodiment of the present
invention there is a forward regulation taking place since it is
conditioned solely on the measured data at the cylinders and such
regulation can take place so fast that any considerable overheating
of the exhaust gas cleaning arrangement is prevented.
BRIEF DESCRIPTION OF THE DRAWING
The invention will become more readily apparent from the following
description of preferred embodiments thereof shown, by way of
example, in the accompanying drawing, in which:
FIG. 1 is a schematic representation of one embodiment of the
exhaust gas cleaning arrangement and its associated control device
applied to a combustion engine and in accordance with the present
invention;
FIG. 2 is a schematic view similar to FIG. 1 illustrating
additional structure;
FIG. 3 is a schematic representation of the exhaust gas cleaning
arrangement comprising the present invention; and
FIG. 4 is a schematic representation of the exhaust gas cleaning
arrangement of the present invention as applied to pluralities of
cylinders arranged in groups.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to the single FIGURE in which the combustion engine
is identified at 1 and in an exemplary fashion it is illustrated as
a four-cylinder machine having cylinders 2, 3 on one side and
cylinders 4, 5 on the other side. In the figure the control
arrangements and other connections are represented only with
respect to one side and it is understood that similar arrangements
and connections are to be had also on the side of cylinders 2, 3 in
a mirror-like fashion of all the parts appearing and shown with
respect to cylinders 4, 5.
In the illustrated embodiments there is only a single catalytically
or thermically operable exhaust gas cleaning arrangement 6 which
can be an arrangement known from the aforementioned applications,
therefore, details of it are not illustrated. The exhaust gas
cleaning arrangement 6 is connected to the common exhaust 7 of
cylinders 4 and 5 and to the common exhaust conduit 8 of cylinders
2 and 3. The clean gases leave the arrangement 6 to the output
conduit 9 which is the usual tail pipe of a combustion engine.
Referring to cylinders 4 and 5 it is noted that the exhaust gases
leave the individual cylinders 4 and 5 through the individual
branches 10 and 11 of the exhaust gas conduit 7. It is also an
important feature of the present invention that the fuel suction
conduit 12 has an individual branch 13 and 14 leading to the
individual cylinders 4 and 5, respectively. In the illustrated
embodiments a combustion engine is shown as having a carborator
which is placed in the region 15. A choke valve 16 including
control means 16a therefor is placed ahead of the carborator 15 in
the suction conduit 12.
Due to unsatisfactory combustion of the charge in the individual
cylinders 2-5 the charge undergoes an after-burning in the exhaust
gas cleaning arrangement 6 which causes the development of
excessively high temperatures in arrangement 6. In the present
embodiments an electric protective arrangement is provided which
assures that in the case when excessively high temperatures appear
in the exhaust gas cleaning arrangement 6 the fuel supply and/or
the combustion air supply to the particular defective cylinder is
reduced or completely disconnected. For the monitoring of the
temperatures existing in the gas cleaning arrangement 6 there is
provided a temperature sensor 17 the electrical output terminal 18
of which, if there is an excess temperature, carries control
signals for the individual closure devices 19 and 20 arranged in
suction conduit branches 13 and 14 as soon as a critical
temperature value has been exceeded in the cleaning arrangement 6.
In order that not all the cylinders would become disconnected from
the supply and thereby causing a stalling of the entire combustion
engine 1, there is provided ahead of each of the energizing or
operating devices 21 and 22 of the closure members 19 and 20 gating
circuits 23 and 24 which, in addition to the control signals
developed by the temperature sensing means 17 in the cleaning
arrangement 6 receive also the output signals of the temperature or
pressure sensors 25 and 26 placed in the individual branches 10 and
11 of the exhaust gas conduit 7. Consequently, only then when the
associated temperature or pressure sensor, such for example, as the
sensor 25, indicates a low exhaust gas temperature or pressure
characteristic of the defectiveness of the associated cylinder 4,
then an appropriate control signal is delivered thereby to the
gating circuit 23 and, when simultaneously an overheating of the
exhaust gas arrangement 6 is sensed by control signals delivered by
the temperature sensor 17, the gate circuit 23 becomes conductive
and passes the control signals from sensor 17, or if necessary
other electrical devices such as amplifiers can be connected to the
output of gate circuit 23, and such output control signal or
signals from the gate circuit 23 arrive at the operating means 21
of the closure member 19 so that the fuelair mixture supply only to
the cylinder 4 becomes interrupted. The remaining cylinders of the
combustion engine 1 will operate further.
In principle would be also possible to place between the outputs of
the sensors 25 and 26 on one hand and between their associated
inputs of the gate circuits 23 and 24 on the other hand, a
comparing circuit 27 (FIG. 2) which similarly as described above
could determine the cylinder which has an especially low exhaust
gas temperature. In the event the output signals of such comparing
circuit 27 are used to control the closure device 21 associated
with the defective cylinder, then the gate circuits 23 and 24 as
well as the temperature sensor 17 could be dispensed with on the
exhaust gas cleaning arrangement 6.
As shown in FIG. 2, there are provided two switching mechanisms 27'
and 27", each one of which is assigned to one of the sensors 25 and
26 at the cylinders 4 and 5. The switches 27' and 27" are designed
in such a manner that they actuate, in each case, one of the
actuation devices 21 and 22 in the sense of decreasing the fuel
supply at the moment when the difference of the output signals are
the two temperature sensors 25 and 26 exceed a certain value. As
can be seen, the output circuits of both temperature sensors 25 and
26 are coupled to the switches 27' and 27". The switches 27' and
27" work as a function of the difference of the output signals of
the two temperature sensors 25 and 26, so that at the time when the
output signal of the sensor 25 is of a smaller order of magnitude
than that of the sensor 26, switch 27' responds, and in the
opposite case, switch 27" responds.
FIG. 3 shows an exemplified embodiment of the present invention
with pressure sensors such as conventional pressure switches 28 and
29, which in each case are connected with the interior of the
cylinders 4 and 5. The drivers or push rods 30 and 31 of the
switches 28 and 29, respectively, which are located on the outlet
side of the switches 28 and 29 engage switches 32 and 33,
respectively. By the actuation of switches 32 and 33, that is an
attainment of a critical pressure value in the cylinder in
question, the gate circuit 23 or 24 which in each instance is
installed beyond the elements here under discussion, is activated.
In all other respects, the embodiment of FIG. 3 operates in the
same manner as the one described in connection with the FIG. 1
embodiment.
FIG. 4 shows the use of a switching system which has been designed
in accordance with the embodiment of FIG. 1 for the case in which
the two cylinders 4 and 5 are grouped together as a cylinder group.
As soon as one of the temperature sensors 25 or 26 ascertains that
one of the cylinders 4 or 5 is not operating in a proper manner,
then an activation of the throttling means 34 takes place for
reducing the fuel and air supply with the activation taking place
through the intervention of the assigned gate circuit 23 or 24. The
throttling means 34 now lies within the suction pipe 15 which is
common to the two cylinders 4 and 5 of this cylinder group. Another
similar throttling means lies in an additional suction pipe which
is common to cylinders 2 and 3. The fuel supply to the cylinder
group 2 and 3 is then adjusted in such a manner, by means of an
additional set-up of the described type, so that no critical
temperature can occur in the common exhaust gas cleaning device
6.
The gate circuit 23 and 24 can be constructed in a simple manner so
that a thermoswitch, part of which forms the sensing means 17, at
the after burner would remain closed at high temperatures, while
thermoswitches monitoring the conditions of the cylinders would be
closed at low temperatures, both switches would be lying in a
common energizing circuit. Parts of the last mentioned
thermoswitches are the sensors 25 and 26. The current would flow
only at excessive temperatures in the after burner or cleaning
arrangement toward the fuel dosing arrangement of each cylinder so
far the thermoswitch of such cylinder would be closed due to low
exhaust temperatures and, consequently, such series arrangement of
the thermoswitches would disconnect the fuel supply only under such
conditions and only for that particular cylinder.
Under the definition of cylinders conventionally the cylinders of a
displacement type piston is understood, however, the concept and
the principles of the present invention should be extended also to
combustion engines having a rotary type piston.
I wish it to be understood that I do not desire to be limited to
the exact details of construction shown and described, for obvious
modifications will occur to a person skilled in the art.
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