U.S. patent number 3,682,152 [Application Number 05/023,281] was granted by the patent office on 1972-08-08 for installation for controlling a combustion engine.
This patent grant is currently assigned to Daimler-Benz Aktiengesellschaft. Invention is credited to Alfred Hermann Muller-berner.
United States Patent |
3,682,152 |
Muller-berner |
August 8, 1972 |
INSTALLATION FOR CONTROLLING A COMBUSTION ENGINE
Abstract
An installation for the control of an internal combustion
engine, particularly for motor vehicles, in which the opening of
the inlet and outlet valve as well as the fuel supply takes place
dependent on the phase angle of the crankshaft; an electronic
control apparatus is provided which is adjustable by means of the
drive pedal; the electronic control apparatus includes a device for
detecting the phase angle of the crankshaft and is connected to the
actuating mechanisms for the inlet and outlet valves as well as for
the fuel injection.
Inventors: |
Muller-berner; Alfred Hermann
(Waiblingen, DT) |
Assignee: |
Daimler-Benz Aktiengesellschaft
(N/A)
|
Family
ID: |
5729708 |
Appl.
No.: |
05/023,281 |
Filed: |
March 27, 1970 |
Foreign Application Priority Data
|
|
|
|
|
Mar 28, 1969 [DT] |
|
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P 19 16 167.2 |
|
Current U.S.
Class: |
123/90.11;
123/90.12; 123/478; 123/493; 123/357; 123/486 |
Current CPC
Class: |
F01L
1/348 (20130101); F02D 13/0253 (20130101); F01L
13/0036 (20130101); F02D 13/0207 (20130101); F01L
13/0015 (20130101); F01L 9/10 (20210101); F02D
41/1446 (20130101); F02D 41/1451 (20130101); F01L
2001/34446 (20130101); Y02T 10/12 (20130101) |
Current International
Class: |
F02D
41/00 (20060101); F01L 1/344 (20060101); F01L
9/02 (20060101); F01L 13/00 (20060101); F01L
1/348 (20060101); F01L 9/00 (20060101); F02D
41/14 (20060101); F02D 13/02 (20060101); F02b
029/08 () |
Field of
Search: |
;123/97,97B,98,99,102,111,114,119,119CE,119C,139,139.17,139.18,140,140.3,32E |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Goodridge; Laurence M.
Claims
I claim:
1. An installation for controlling a combustion engine of the type
having inlet and outlet valve means, fuel supply means, and a
crankshaft wherein the actuation of the valve means and the fuel
supply means is dependent upon the phase angle of the crankshaft;
the installation comprising an output adjusting member for the
combustion engine providing an electrical output signal indicative
of the output desired, means for detecting the rotational speed and
phase angle of the crankshaft for providing an electrical output
signal indicative thereof, and electronic means responsive to
operating parameters of the engine including the output signals
from the output adjusting member and the crankshaft detecting means
for providing separate electrical output signals to each of the
inlet and outlet valve means for controlling at least one of the
stroke and timing of one of the inlet and outlet valve means
independently of at least one of the stroke and timing of the other
of the inlet and outlet valve means, said electronic means also
providing an electric output signal to the fuel supply means for
controlling the supply of fuel to the engine independently of at
least one of the stroke and timing of the inlet and outlet valve
means.
2. An installation according to claim 1 characterized in that a
pulse transmitter means dependent on the rotation of the crankshaft
serves as means for detecting the phase angle of the
crankshaft.
3. An installation according to claim 2, characterized in that the
pulse transmitter means includes electromagnetic teeth means
provided at a flywheel and constructed in the manner of a recording
tape and magnet means having winding means and constructed in the
manner of a recording head, said winding means being operatively
connected with said electronic control means.
4. An installation according to claim 3, characterized in that the
inlet and outlet valve means include hydraulic piston means which
are adapted to be connected with a pressure tank containing a
pressure medium by way of magnetic valve means controlled by the
electronic control means.
5. An installation according to claim 4, characterized in that both
sides of the hydraulic piston means are adapted to be acted upon by
the pressure medium of the pressure tank for movement of the piston
means in different directions.
6. An installation according to claim 5, characterized in that the
inlet and outlet valve means includes displacement transmitter
means providing an output indicative of the displacement of the
inlet valve and outlet valve means, and connecting means
operatively connecting said displacement transmitter means with
said electronic control means.
7. An installation according to claim 6, characterized in that the
inlet and outlet valve means includes a throttle means provided in
the discharge from the pressure spaces of the piston means for
throttling during closing operation of the inlet and outlet valve
means.
8. An installation according to claim 1, characterized in that the
inlet and outlet valve means include hydraulic piston means which
are adapted to be connected with a pressure tank containing a
pressure medium by way of magnetic valve means controlled by the
electronic control means.
9. An installation according to claim 8, characterized in that both
sides of the hydraulic piston means are adapted to be acted upon by
the pressure medium of the pressure tank for movement of the piston
means in different directions.
10. An installation according to claim 8, characterized in that the
inlet and outlet valve means includes displacement transmitter
means providing an output indicative of the displacement of the
inlet valve and outlet valve means and connecting means operatively
connecting said displacement transmitter means with said electronic
control means.
11. An installation according to claim 8, characterized in that the
inlet and outlet valve means includes a throttle means provided in
the discharge from the pressure spaces of the piston means for
throttling during the closing operation of the inlet and outlet
valve means.
12. An installation according to claim 1, characterized in that the
inlet valve and outlet valve means includes a valve drive means
comprising chain and sprocket drive means in which the length of
the pulling section of the chain between a camshaft sprocket wheel
and a crankshaft sprocket wheel is adapted to be adjusted by a
chain guidance means operatively connected with the control
means.
13. An installation according to claim 12, characterized in that
the chain guidance means includes displacement transmitter means
operatively connected with the control means.
14. An installation according to claim 13, characterized in that
the displacement transmitter means is an inductive displacement
pick-up.
15. An installation according to claim 12, characterized in that
the camshaft operatively connected with a servo-means is
displaceably arranged and is provided with cams axially offset to
one another, said servo-means being operatively connected by said
connecting means with said electronic control means.
16. An installation according to claim 15, characterized in that
the camshaft is connected with a displacement transmitter means
operatively connected with the electronic control means.
17. An installation according to claim 16, characterized in that
said displacement transmitter means is an inductive displacement
pick-up.
18. An installation according to claim 16, characterized in that
the chain guidance means includes displacement transmitter means
operatively connected with the control means.
19. An installation according to claim 18, characterized in that
the displacement transmitter means are inductive displacement
pick-ups.
20. An installation according to claim 1, characterized in that the
fuel supply means includes a magnetic valve means which is adapted
to be controlled by the electronic control means, said magnetic
valve means being operatively connected with a pressure tank and an
injection nozzle of the fuel supply means for controlling the
supply of fuel.
21. An installation according to claim 20, characterized in that
the magnetic valve means and the injection nozzle are combined into
a structural unit.
22. An installation according to claim 1, characterized by the
electronic control means being responsive to measuring means for
detecting the condition of the combustion air, the measuring means
being arranged in the suction line of the engine.
23. An installation according to claim 1, characterized by the
electronic control means being responsive to pressure indicator
means arranged in the combustion space of the engine.
24. An installation according to claim 1, characterized by the
electronic control means being responsive to temperature indicator
means arranged in the combustion space of the engine.
25. An installation according to claim 22, characterized by the
electronic control means being responsive to pressure and
temperature indicator means arranged in the combustion space of the
engine.
26. An installation according to claim 1, characterized by the
electronic control means being responsive to measuring means
arranged in the exhaust gas line of the engine.
27. An installation according to claim 26, wherein said measuring
means measures the smoke factor.
28. An installation according to claim 26, characterized in that
the measuring means measures the temperature.
29. An installation according to claim 25, characterized by the
electronic control means being responsive to measuring means
arranged in the exhaust gas line of the engine.
30. An installation according to claim 29, characterized in that
said last-mentioned measuring means is operable to measure both the
smoke number and the temperature.
31. An installation according to claim 1, characterized in that the
output adjusting member is a drive pedal of a motor vehicle.
32. An installation according to claim 30, characterized in that a
pulse transmitter means dependent on the rotation of the crankshaft
serves as means for detecting the phase angle of the
crankshaft.
33. An installation according to claim 32, characterized in that
the pulse transmitter means includes electromagnetic teeth means
provided at a flywheel and constructed in the manner of a recording
tape and magnet means having winding means and constructed in the
manner of a recording head, said winding means being operatively
connected with said electronic control means.
34. An installation according to claim 33, characterized in that
the inlet and outlet valve means include hydraulic piston means
which are adapted to be connected with a pressure tank containing a
pressure medium by way of magnetic valve means controlled by the
electronic control means.
35. An installation according to claim 34, characterized in that
both sides of the hydraulic piston means are adapted to be acted
upon by the pressure medium of the pressure tank for movement of
the piston means in different directions.
36. An installation according to claim 34, characterized in that
the inlet and outlet valve means includes displacement transmitter
means providing an output indicative of the displacement of the
inlet valve and outlet valve means, and connecting means
operatively connecting said displacement transmitter means with
said electronic control means.
37. An installation according to claim 36, characterized in that
the inlet and valve means includes a throttle means provided in the
discharge from the pressure spaces of the piston means for the
throttling during the closing operation of the inlet and outlet
valve means.
38. An installation according to claim 33, characterized in that
the inlet valve and outlet valve means includes a valve drive means
comprising chain and sprocket drive means in which the length of
the pulling section of the chain between a camshaft sprocket wheel
and a crankshaft sprocket wheel is adapted to be adjusted by a
chain guidance means operatively connected with the control
means.
39. An installation according to claim 38, characterized in that
the chain guidance means includes displacement transmitter means
operatively connected with the control means.
40. An installation according to claim 39, characterized in that
the camshaft operatively connected with a servo-means is
displaceably arranged and is provided with cams axially offset to
one another, said servo-means being operatively connected by said
connecting means with said electronic control means.
41. An installation according to claim 40, characterized in that
the camshaft is connected with a displacement transmitter means
operatively connected with the electronic control means.
42. An installation according to claim 33, characterized in that
the output adjusting member is a drive pedal of a motor vehicle.
Description
The present invention relates to an installation for the control of
an internal combustion engine, especially for motor vehicles in
which the opening of the inlet valves and of the outlet valves as
well as the fuel supply takes place dependent on the phase angle of
the crankshaft.
With the known internal combustion engines, a purely mechanical
connection between the crankshaft and the control members, properly
speaking, is provided for the engine control. An injection pump is
customarily actuated from the crankshaft by way of a cam shaft.
Additionally, a cam shaft is driven from the crankshaft by way of
gears, which cam shaft force-lockingly controls a cam shaft either
directly or by way of tappets, push rods and rocker arms the inlet
and the outlet valves which are retained in the closed position
thereof by springs. The opening takes place against the spring
force. These mechanical control systems have the disadvantage that
the control characteristics cannot be matched or adapted to the
requirements of the different types of operation and/or operating
conditions at a different rotational speed, torque, smoke
development, or the like.
The present invention is based on the aim to avoid these
disadvantages and to create an installation of the aforementioned
type which permits an arbitrary change at will of the control
characteristics in dependence on the desired torque, rotational
speed and power-utilization and/or which permits an adjustment to
optimum predetermined operating conditions.
The present invention essentially consists in that an electronic
control apparatus is provided adjustable by way of the drive pedal,
which includes an installation for detecting the phase angle of the
crankshaft and which is operatively connected to actuating
installations for the inlet valve or valves and the outlet valve or
valves as well as the fuel injection. The electronic control
apparatus possesses the possibility to permit any desired
adjustment by means of present programs and/or by way of data taken
off at different places of the engine, by adapting the opening of
the moment of the valve and the injection moment of the fuel.
Advantageously, a pulse transmitter dependent on the rotation of
the crankshaft may serve as installation for detecting the phase
angle of the crankshaft. As a result of such an arrangement, the
electronic control apparatus possesses exact informations
concerning the accurate phase angle of the crankshaft and the
rotational speed thereof. In a structurally advantageous manner,
the pulse transmitter may consist of an electromagnetic toothed
arrangement mounted at the flywheel and constructed in the manner
of a recording tape and of a magnet provided with windings and
constructed in the manner of a recording head whose windings are
connected with the control apparatus. The electronic control
apparatus is thus informed by way of an electric or electronic
pulse counter of conventional construction concerning the phase
angle of the crankshaft and the rotational speed thereof.
It is structurally advantageous if the inlet and outlet valve are
connected with hydraulic pistons which are adapted to be connected
with a pressure tank or reservoir by way of magnetic valves
controlled by the control apparatus. In order to realize also the
closing of the valves hydraulically, both sides of the hydraulic
pistons may be actuatable with the pressure medium. In order to be
able to monitor and check the position and also the load of the
valves, displacement pick-ups or transmitters may be connected with
the inlet valves and the outlet valves which are operatively
connected with the control apparatus. These displacement pick-ups
or indicators permit to the electronic control apparatus to
calculate velocity and acceleration of the valves whereby a
possibly predetermined maximum acceleration may lead to the
limitation of the stroke or of the actuating velocity in order to
avoid a fluttering of the valves after the closing under spring
force. However, it is particularly advantageous in order to prevent
at high rotational speed a valve-jumping after the closing if a
throttling means is provided in the discharge of the pressure
spaces to be emptied out during the closing operation of the inlet
valves and of the outlet valves. This throttle means prevents a
sudden closing of the valves.
In another embodiment of the present invention, a conventional
valve drive equipped with a camshaft driven by way of a chain may
be provided for the inlet and the outlet valves in which the length
of the chain between the camshaft gear and the crankshaft gear is
adapted to be changed by way of a chain guidance connected with the
control apparatus. It becomes possible thereby to influence the
control characteristics by the adjustment of the camshaft with
respect to the crankshaft. It is thereby appropriate if the chain
guidance is equipped with a preferably inductive displacement
pick-up or transmitter connected with the control apparatus. In
order to achieve changes in time of the control characteristics, it
is additionally possible to arrange the camshaft in a displaceable
manner which is connected with a servo-mechanism that is
operatively connected with the control apparatus. It is thereby
also advantageous for purposes of monitoring and controlling to
provide the camshaft with a preferably inductive displacement
pick-up or transmitter operatively connected with the control
apparatus.
According to a further advantageous feature of the present
invention, a magnetic valve adapted to be controlled by the control
apparatus may be provided as actuating installation for the fuel
injection which is connected with a pressure tank and with the
injection nozzle. It is structurally advantageous if the magnetic
valve and the injection nozzle are combined into a structural
unit.
In order to attain an optimum combustion, a measuring apparatus
operatively connected with the control apparatus and detecting the
condition of the combustion air may be arranged in the suction
line. The informations supplied by this measuring apparatus to the
electronic control apparatus permits the control apparatus to
correspondingly adapt the control characteristics.
Furthermore, a pressure and/or temperature indicator may be
arranged in the combustion space which is operatively connected
with the control apparatus. With the use of such indicating
apparatus the load of the engine may be monitored and controlled by
the electronic control apparatus.
Therebeyond, it may be advantageous if an apparatus measuring the
smoke number and the temperature is arranged in the exhaust gas
line which is operatively connected with the control apparatus. The
quality of the combustion can be monitored thereby and also
controlled.
Accordingly, it is an object of the present invention to provide an
installation for the control of an internal combustion engine which
avoids by simple means the aforementioned shortcomings and
drawbacks.
Another object of the present invention resides in an installation
for controlling a combustion engine which permits an adaption of
the control characteristics to the requirements of the different
types of operation and operating conditions.
A further object of the present invention resides in an
installation for the control of a combustion engine which permits
any suitable change in the control characteristics to assure
optimum operating conditions, yet is simple in construction and
reliable in operation while utilizing standardized, commercially
available parts.
These and further objects, features and advantages of the present
invention will become more obvious from the following description
when taken in connection with the accompanying drawing which shows,
for the purposes of illustration only, several embodiments in
accordance with the present invention, and wherein:
FIG. 1 is a schematic view, partly in cross-section, of an
installation for the control of an internal combustion engine in
accordance with the present invention;
FIG. 2 is a schematic view, similar to FIG. 1, of a modified
embodiment of a control installation in accordance with the present
invention;
FIG. 3 is a schematic view, similar to FIGS. 1 and 2, of a still
further modified embodiment of a control installation in accordance
with the present invention;
FIG. 4 is a partial, somewhat schematic view illustrating certain
details in an embodiment corresponding to FIG. 3;
FIG. 5 is a schematic block diagram illustrating schematically the
control apparatus 12 of FIGS. 1 and 2; and
FIG. 6 is a schematic block diagram illustrating schematically the
control apparatus 12 of FIGS. 3 and 4.
Referring now to the drawing wherein like reference numerals are
used throughout the various views to designate like parts, and more
particularly to FIG. 1, this figure illustrates a cross section
through a schematically illustrated internal combustion engine in
which a piston 2 reciprocating within a cylinder linear 1 drives a
crankshaft 5 supported in a crank housing 4 by way of a connecting
rod 3. The combustion space 6 disposed above the cylinder is closed
by a cylinder head 7 whose inlet channel 8 and outlet channel 9 are
closed, respectively, by an inlet valve 10 and an outlet valve 11.
Additionally, the cylinder head 7 is provided with an injection
nozzle projecting into the combustion space for the fuel
supply.
An electronic control apparatus 12 is provided for the control of
the combustion engine which is connected with a battery 13. The
desired adjustment of the torque is preset for the electronic
control apparatus 12 by means of a potentiometer 15 connected with
the drive pedal or gas pedal 14. The control apparatus 12 (FIGS. 1
and 5) is of conventional construction, utilizing commercially
available components and involving circuits, known as such in the
prior art and therefore not described in detail herein.
The electronic control apparatus 12 is provided with an
installation for detecting the phase angle .alpha. of the
crankshaft 5, which transmits accurate informations concerning the
phase angle .alpha. of the crankshaft 5 and the rotational speed
thereof. The installation for detecting the phase angle of the
crankshaft 5 and the rotational speed consists of an electric pulse
transmitter. For that purpose, an electromagnetic toothed
arrangement 17 constructed in the manner of a recording tape, is
provided at the flywheel 16 that is rigidly connected with the
crankshaft 5. The toothed arrangement 17 rotates past a magnet 19
provided with a winding 18 and effective in the manner of a
recording head. The pulse counting commences with a zero position
20. Simultaneously, the electronic control apparatus 12 is pre-set
by way of the potentiometer 15 coupled with the driving pedal 14 to
pre-select the torque of the engine to be produced.
The electronic control apparatus 12 processes in a conventional
manner the information reaching the same into electric pulses which
are transmitted to the actuating installations of conventional
construction for the inlet valve 10 and the outlet valve 11 as well
as for the fuel injection. The inlet and outlet valves 10 and 11
are each provided with a hydraulic piston 21 which are adapted to
be connected by way of a respective magnetic valve 22 shifted by
the pulses of the control apparatus 12 with a respective local high
pressure tank 23. The local high pressure tanks 23 are fed by way
of a supply line from a central pressure tank 24 which is re-filled
by way of a high pressure pump 25, a pressure regulator 26 and a
check valve 27 from a supply tank 28. Compression springs 29 are
provided in this embodiment for the closing of the inlet and valves
10 and 11. The inlet and the outlet valves 10 and 11 are
additionally equipped each with a displacement pick-up or
transmitter 30 which feed back to the electronic control apparatus
12 the instantaneous position of the valves 10 and 11. From these
informations, the electronic control apparatus 12 calculates the
velocity and the acceleration whereby a possibly predetermined
maximum acceleration may lead to the limitation of the stroke or of
the actuating velocity in order to avoid a fluttering of the valves
10 and 11 after the renewed closing under spring pressure. Another
possibility, in order to avoid at very high rotation speeds a
valve-jumping or skipping after the closing, essentially consists
in installing into the discharge lines of the magnetic valves 22 a
throttle means so that the oil pressure is not suddenly reduced in
the pressure spaces to be emptied during the closing. The data
transmitted to the control apparatus 12 are compared in a
conventional manner with intended or pre-set values which,
themselves are a function of engine, rotational speed and torque.
Possibly necessary corrections are then carried out conventionally
by the electronic control apparatus 12. Since such electronic
control apparatus 12 as well as its logic circuit elements are
known in the art and form no part of the present invention, the
overall arrangement of such conventional circuits is merely
indicated schematically in block diagram in FIG. 5 while a detailed
description is dispensed with herein.
A further magnetic valve 31 is provided for the fuel injection
which connects an injection nozzle 32 with the high pressure tank
33 containing a fuel in the presence of a pulse from the control
apparatus 12. It is appropriate in practice to construct the
injection nozzle 32 and the magnetic valve 31 as a unit. The high
pressure tank 33 is re-charged or re-supplied with fuel from a tank
35 by way of a high pressure fuel pump 34.
By the accommodation of a pressure indicator 36 in the combustion
space 6 as well as of a temperature and humidity measuring device
37 in the suction channel 8 for the combustion air and of a
smoke-number and/or temperature-measuring device 38 in the exhaust
or exhaust channel 9, which are all connected to the electronic
control apparatus 12, the data thereof can be conventionally
evaluated by the electronic control apparatus 12. It is possible
thereby, in conjunction with the position of the foot pedal 14 to
so control the injection quantity and valve control periods that
all of the engine operating conditions desired by the driver such
as minimum consumption, minimum smoke development and emission,
optimum charging degree, possibly a maximum torque in case of need,
momentary overloads or favorable noise behavior, for example, by
the limitation of the pressure rise as a function of the phase
angle of the crankshaft 5, may be selectively adjusted. It is also
possible therebeyond to so convert the engine torque
characteristics that with a decreasing rotational speed the torque
increases in order to achieve thereby a more stable behavior and a
reduction of the number of speeds of the transmission. Furthermore,
it is possible to utilize the engine as exhaust brake without any
constructive change-over. In that connection, also the inlet valve
10, in addition to the outlet valve 11, could be kept closed for
the reduction of the reaction in the inlet channel 8. The
compression work can then be dissipated by temporary opening of the
exhaust valve 11. A higher engine braking output may be achieved
thereby without additional brake elements than is possible with the
known exhaust brakes. Additionally, the maximum rotational speed
range of the engine can be increased by the limitation of the valve
stroke at higher rotational speeds.
The embodiment according to FIG. 2 is changed in that the springs
29 of FIG. 1 for the closing of the inlet valve 10 and of the
outlet valve 11 are dispensed with. In this embodiment, both the
opening as also the closing of the inlet valve 10 and of the outlet
valve 11 takes place by one double-acting hydraulic piston 39 each
provided on a respective valve stem, the valve which is adapted to
be acted upon with the pressure medium on both sides. Two further
magnetic valves 40 are necessary therefor which during closing of
the valves 10 and 11 let pressure act on the bottom side of the
hydraulic pistons 39.
In the embodiment according to FIG. 3, a mechanical valve drive has
been maintained. In this embodiment the crankshaft 5 is provided
with a sprocket wheel 41 which drives by way of a chain 42 and a
sprocket wheel 43, a camshaft 44 which, in its turn, actuates the
corresponding valve 48 by way of a tappet 45, a pushrod 46 and a
rocker arm 47. In the drawing, only the control of the inlet valve
48 is illustrated whereas the control for the outlet valve, which
takes place in the same manner, is not shown. In order to be able
to change the control periods of the valves, a chain guide means is
provided, by means of which a phase shift between the crankshaft 5
and the camshaft 44 is possible. A magnetic valve 49 fed with
pressure oil serves for this purpose which is able to adjust by way
of a servo-mechanism the chain guide means so that the length of
the pulling section of the chain and therewith also the phase
between the camshaft and the crankshaft is changed. The chain guide
means consists of a piston chain 51 connected with a piston 50
which includes two chain rollers 52. For the adjustment of the
piston 50, pressure oil may be supplied pursuant to a pulse of the
electronic control apparatus 12 (FIG. 6), to the piston 50 of the
piston rod 51 by way of the valve 49 from a high pressure tank 53.
The high pressure tank 53 is charged or refilled by a high pressure
pump 54 by way of a pressure regulator 55 and a check valve 56. The
magnetic valve 49 is provided with a return-line 58 leading back to
the supply tank 57. The chain guidance means 50, 51, and 52 is
additionally provided with a chain-tensioning roller 59 which is
under a spring-load. The feedback concerning the instantaneous
position of the inlet and outlet control periods takes place by way
of an inductive displacement pick-up or transmitter 60 which is
connected with the chain guide means and transmits its signals to
the electronic control apparatus 12. The data transmitted from the
inlet channel 8 and the exhaust channel 9 as well as from the
combustion space as well as the preset program of the electronic
control apparatus 12 are influenced also by this feedback from the
inductive displacement transmitter 60.
In order to be able not only to shift the control periods but also
to change the same, the camshaft 44, as illustrated in FIG. 4, may
be additionally arranged in a displaceable manner. For this
purpose, for example, a servo-motor 61 with a magnetic valve 62 may
be provided which is also connected with pressure supply lines and
which is controlled by a pulse of the electronic control apparatus
12. The extension of the camshaft 44 is attached to the piston 63
of the servo motor 61. In the illustrated embodiment according to
FIG. 4, two different cam tracks or configurations 64 and 65 are
provided. The influencing of the duration or length of the control
periods takes place thereby by way of the magnetic valve 62 which
is shifted by the electric control apparatus 12 in accordance with
the data, made available, as already described, of the engine
and/or according to a preset program of the magnetic valve 62. In
order to feedback the duration of the control periods to the
electronic control apparatus 12 (FIG. 6), a similar inductive
displacement pick-up or transmitter may be provided as is utilized
for the chain guidance 50, 51 and 52 with the shift of the control
periods.
As mentioned above, the electronic control apparatus 12 of the
various embodiments is of conventional construction utilizing
conventional logic elements in its circuits in a conventional
manner, FIGS. 5 and 6 being illustrative of such control apparatus,
illustrating in block diagram the conventional connections of such
commercially available logic elements.
While I have shown and described only several embodiments in
accordance with the present invention, it is understood that the
same is not limited thereto but is susceptible of numerous changes
and modifications as known to those skilled in the art, and I
therefore do not wish to be limited to the details shown and
described herein but intend to cover all such changes and
modifications as are encompassed by the scope of the appended
claims.
* * * * *