U.S. patent application number 13/625916 was filed with the patent office on 2014-08-21 for cooling circuit for a liquid-cooled internal combustion engine.
This patent application is currently assigned to MAN Truck & Bus AG. The applicant listed for this patent is Martin Bohm. Invention is credited to Martin Bohm.
Application Number | 20140230758 13/625916 |
Document ID | / |
Family ID | 46581703 |
Filed Date | 2014-08-21 |
United States Patent
Application |
20140230758 |
Kind Code |
A9 |
Bohm; Martin |
August 21, 2014 |
Cooling Circuit For A Liquid-Cooled Internal Combustion Engine
Abstract
A cooling circuit for a liquid-cooled internal combustion engine
for motor vehicles, includes a main cooling circuit including a
feed line leading to a radiator and a return line, and a bypass
line, which bypasses the radiator and can be controlled as a
function of temperature and secondary cooling circuit for a
retarder of a braking device of the motor vehicle, which is
connected, likewise by a feed line, a return line and a control
valve, to the main cooling circuit. The two cooling circuits (2, 3)
can be controlled by a single rotary slide valve (10). Both cooling
circuits (2, 3) are interconnected in such a way that the flow
rates thereof to the radiator (6) and/or to the retarder (4) can be
varied in a predetermined or defined manner, in particular between
0% and 100%.
Inventors: |
Bohm; Martin; (Burgthann,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bohm; Martin |
Burgthann |
|
DE |
|
|
Assignee: |
MAN Truck & Bus AG
Muenchen
DE
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20140083376 A1 |
March 27, 2014 |
|
|
Family ID: |
46581703 |
Appl. No.: |
13/625916 |
Filed: |
September 25, 2012 |
Current U.S.
Class: |
123/41.1;
123/41.59 |
Current CPC
Class: |
F01P 2060/06 20130101;
Y10T 137/86533 20150401; F01P 7/14 20130101; Y10T 137/86493
20150401; F01P 7/165 20130101 |
Class at
Publication: |
123/41.1;
123/41.59 |
International
Class: |
F01P 7/14 20060101
F01P007/14 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 26, 2011 |
DE |
10 2011 116 933.8 |
Claims
1. A cooling circuit for a liquid-cooled internal combustion engine
for a motor vehicle comprising: a main cooling circuit (2)
including a radiator (6); a feed line (5) leading to said radiator
(6); and a return line (7) leading away from said radiator (6); a
bypass line (9) bypassing said radiator (6) and constructed so as
to be controllable as a function of predetermined parameters; a
retarder (4) of a braking device; a secondary cooling circuit (3)
for said retarder (4), said secondary cooling circuit (3) having a
feed line (11) and a return line (12); said main cooling circuit
(2) having a flow rate to said radiator (6) and said secondary
cooling circuit (3) having a flow rate to said retarder (4); a
single rotary slide valve (10) arranged for controlling said main
cooling circuit (2) and said secondary cooling circuit (3); said
main cooling circuit (2) and said secondary cooling circuit (3)
being interconnected for varying at least one of the flow rate to
said radiator (6) and the flow rate to said retarder (4) in a
defined manner.
2. The cooling circuit according to claim 1, wherein one of the
flow rate of said radiator (6) and the flow rate of said retarder
(4) is varied between 0% and 100%.
3. The cooling circuit according to claim 1, wherein said rotary
slide valve (10) comprises a housing (10a) having four throughflow
openings therein and being inserted into said feed line (5) leading
from the internal combustion engine to said radiator (6); said
bypass line (9) being connected to a third throughflow opening of
said rotary slide valve between said feed line (5) and said return
line (12); said return line (12) of said retarder (4) connected to
a fourth throughflow opening (15); and wherein said feed line (11)
of said retarder (4) is connected to said feed line (5a) of said
main cooling circuit (3) upstream of said rotary slide valve
(10).
4. The cooling circuit according to claim 3, wherein three of said
four throughflow openings are arranged radially on said housing
(10a) of said rotary slide valve (10); said rotary slide valve
further comprising a crescent-shaped rotary slide (10b); said
fourth throughflow opening (15) for said return line (12) of said
retarder (4) being aligned axially with respect to said rotary
slide (10b) and being permanently open.
5. The cooling circuit according to claim 4, wherein said three
throughflow openings are arranged in one of a common plane and so
as to be distributed in a circumferential direction.
6. The cooling circuit according to claim 4, wherein said rotary
slide valve (10) is crescent shaped in cross section.
7. The cooling circuit according to claim 3, additionally
comprising a restriction element (13) disposed in said feed line
(5) leading from the internal combustion engine to said radiator
(6) upstream of said rotary slide valve (10) but downstream of a
branch point of said feed line (11) of said secondary cooling
circuit (3); said restriction element (13) designed to ensure a
minimum throughput of cooling liquid through said retarder (4).
8. The cooling circuit according to claim 1, additionally
comprising a delivery device (8) having a delivery rate and
disposed into said main cooling circuit 2.
9. The cooling circuit according to claim 8, wherein said delivery
device is a delivery pump.
10. The cooling circuit according to claim 9, wherein said delivery
pump is one of output-controlled and capable of temporarily being
operated with a greater or lesser delivery rate in accordance with
the operating position of said rotary slide valve 10.
11. The cooling circuit according to claim 8, wherein said delivery
device (8) is one of an electrically controllable delivery pump and
a mechanical delivery pump, said mechanical delivery pump including
a coupling device for coupling said delivery pump to the internal
combustion engine (1) and an adjusting device for controlling said
delivery rate of said delivery device.
12. The cooling circuit according to claim 11, wherein said
coupling device is a belt drive (17).
13. The cooling circuit according to claim 11, wherein said
adjusting device is a clutch device (18) or an adjustable guide
vane arrangement (19).
14. The cooling circuit according to claim 8, wherein said rotary
slide valve (10) is constructed so as to be capable of one of
decoupling said retarder (4) and bypassing said main cooling
circuit (3) thereby reducing the delivery rate of said delivery
device in relation to a constant delivery rate.
15. The cooling circuit according to claim 1, additionally
comprising an auxiliary power device for adjusting said rotary
slide valve (10), wherein parameters of one of the operating
temperatures (T) of said cooling circuits (2, 3), the load states
(L) of the internal combustion engine and the operating states (R)
of said retarder (4) are detected and at least one of said rotary
slide valve (10) and said delivery rate of said delivery pump is
adjusted in accordance with said parameters.
16. The cooling circuit according to claim 1, additionally
comprising a control unit (14) including a feedback system; and
wherein said rotary slide valve additionally comprises at least one
position sensor (20) for monitoring the operation of said rotary
slide valve in said feedback control system of said control
unit.
17. The cooling circuit according to claim 1, wherein said rotary
slide valve (10) is constructed so as to activate said retarder (4)
in a heating function for the internal combustion engine and the
secondary cooling circuit (3) is connected temporarily to said
bypassed main cooling circuit (3).
18. The cooling circuit according to claim 4, wherein said rotary
slide (10b) of said rotary slide valve (10) is spring-loaded into a
predetermined operating position so that both said main cooling
circuit (2) and said secondary cooling circuit (3) are connected to
said radiator (6) of said main cooling circuit (2) in terms of
flow.
19. The cooling circuit according to claim 8, wherein said rotary
slide valve (10) and said delivery device (8) of said main cooling
circuit (2) are arranged in a common housing.
20. A method of operating a cooling circuit according to claim
1.
21. The cooling circuit according to claim 15, wherein said
auxiliary power device is one of an electrical, pneumatical,
hydraulic and magnetical power device.
22. The cooling circuit according to claim 21, wherein said
auxiliary power device is a stepper motor (20).
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a cooling circuit for a
liquid-cooled internal combustion engine for motor vehicles
including a control valve for controlling the flow rates.
[0003] 2. Description of the Related Art
[0004] US published application US2007/0131181A1 describes a
cooling circuit for an internal combustion engine, which has a main
cooling circuit for the internal combustion engine and a secondary
cooling circuit for a retarder as a braking device of the motor
vehicle. The main cooling circuit, which has an integrated bypass
line for decoupling the radiator when the internal combustion
engine is still cold, is controlled by a thermostatic valve. The
heat generated in the retarder in the activated state or braking
mode, is dissipated via the main cooling circuit. In this
arrangement, a changeover valve is integrated into the secondary
cooling circuit and, by this valve, the secondary cooling circuit
can be decoupled when the retarder is not activated in order to
relieve the load on the delivery pump supplying both cooling
circuits.
[0005] It is an object of the invention to provide a cooling
circuit of the type in question which, while involving little
outlay on construction, allows improved thermal design and control
of the fluid flows in both circuits.
SUMMARY OF THE INVENTION
[0006] According to the present invention, the two cooling circuits
are controlled by a single rotary slide valve which has a housing
with throughflow openings. The two cooling circuits are
interconnected at the rotary slide valve in such a way that the
flow rates thereof to the radiator and/or to the retarder can be
varied in a predetermined or defined manner, preferably between 0%
and 100%. The rotary slide valve not only makes it possible
selectively to decouple the radiator and/or the secondary circuit
of the retarder but also allows any desired intermediate positions
for improved thermal control and adaptation to various operating
states of the internal combustion engine and of the retarder, and
does so in a manner which is simple in terms of construction and of
control engineering.
[0007] In a particularly advantageous embodiment, the housing of
the rotary slide valve has four throughflow openings and can be
inserted into the feed line leading from the internal combustion
engine to the radiator, wherein the bypass line is connected
between the feed line and the return line of the main circuit by a
third throughflow opening, and, finally, the return line of the
retarder is connected to the fourth throughflow opening, and
wherein furthermore the feed line of the retarder is connected to
the feed line of the main cooling circuit upstream of the rotary
slide valve.
[0008] In an embodiment of the rotary slide which is simple in
terms of design, three of the throughflow openings can be arranged
radially and so as to be distributed in a circumferential direction
on the housing of the rotary slide valve, and can be controlled by
a rotary slide, e.g. a rotary slide which is crescent-shaped in
cross section, and wherein the fourth throughflow opening for the
return line of the retarder is aligned axially with respect to the
rotary slide and is continuously open. This has the advantage, in
particular, that only three throughflow openings have to be
controlled by the rotary slide, while, in the case of the
continuously open throughflow opening, the flow resistance of the
secondary circuit is incorporated into the control system.
[0009] For this purpose, it can furthermore be advantageous if a
restriction element is provided in the feed line leading from the
internal combustion engine to the radiator, upstream of the rotary
slide valve but downstream of the branch point of the feed line of
the secondary cooling circuit, said restriction element ensuring a
minimum throughput of cooling fluid through the retarder. By way of
example, the restriction element can be formed by an orifice plate
or a reduction in cross section in the region of the rotary slide
feed.
[0010] In a particularly advantageous embodiment of the invention,
a delivery device, in particular a delivery pump, is inserted into
the main cooling circuit, and preferably provision is made for the
delivery device in the main cooling circuit to be of
output-controlled design and/or to be capable temporarily of
operation with a greater or lesser delivery rate in accordance with
the operating position of the rotary slide valve. In this case, the
delivery device can be formed by an electrically controllable
delivery pump, for example, or, alternatively, can be formed by a
mechanical delivery pump which is coupled to the internal
combustion engine and hence to the rotational speed thereof by a
coupling device, e.g. by a belt drive as schematically shown at 17
in FIG. 10. In the latter case, the delivery rate can, in turn, be
controllable by an adjusting device, it being possible, for
example, for a clutch device as schematically shown at 18 in FIG.
10 to be used as an adjusting device, e.g. a magnetic clutch or a
viscous coupling, to name just a few examples. As an alternative or
in addition, however, the adjusting device can also be formed by an
adjustable guide vane arrangement as schematically shown at 19 in
FIG. 10. In the case of such a construction, the driving power for
the delivery pump can be significantly reduced (while the delivery
rate remains constant) when the retarder is decoupled by the rotary
slide valve and/or when the main cooling circuit is operated in
bypass mode (with no flow through the radiator), thus making it
possible to save motive power from the internal combustion
engine.
[0011] In a preferred embodiment, the rotary slide valve or rotary
slide can be adjustable electrically by a stepper motor, wherein
the operating temperatures of the cooling circuits, load states of
the internal combustion engine and operating states of the service
brake of the motor vehicle are detected, and the rotary slide and,
if appropriate, the delivery rate of the delivery pump are adjusted
in accordance with said data. In a preferred embodiment, the
stepper motor can adjust the rotary slide in both directions of
rotation and thus control different switching sequences.
[0012] To achieve a failsafe setting, it is furthermore possible to
provide the rotary slide valve with at least one position sensor,
e.g. a rotation angle sensor, and for the operation thereof to be
monitored electronically in a feedback control system. If a
malfunction is detected, a warning signal can then be generated
and/or a safety position of the rotary slide can be adopted (e.g.
both cooling circuits are opened, increase in the output of the
delivery pump etc.).
[0013] In a heating function for the internal combustion engine
(e.g. in the case of extremely low outside temperatures and/or for
comfortable cold driving performance and/or for a rapid response
from an interior heating system connected to the main cooling
circuit), the retarder can furthermore be activated and the
secondary cooling circuit thereof can be connected temporarily to
the bypassed main cooling circuit by the rotary slide valve. This
results in a dual effect owing to the heating of the retarder, on
the one hand, while, on the other hand, the braking mode thereof
leads to higher driving power from the internal combustion engine
combined with a higher temporary fuel flow rate and more rapid
warming up of the internal combustion engine.
[0014] The rotary slide of the rotary slide valve can be
spring-loaded into a predetermined position, in which both the main
cooling circuit and the secondary cooling circuit are connected to
the radiator of the main cooling circuit in terms of flow. This is
an advantageous way of ensuring that the cooling of the internal
combustion engine and of the retarder is maintained if there is a
failure in the electric actuating system of the rotary slide. The
preloading can be produced by leg springs acting on the rotary
slide and on the housing in a circumferential direction, for
example.
[0015] Finally, in a design which is compact in terms of
construction and advantageous in terms of weight, the rotary slide
valve and the delivery pump of the main cooling circuit can be
arranged in a common housing.
[0016] A method for operating the above described cooling circuit
to achieve the abovementioned advantages, is also claimed.
[0017] Other objects and features of the present invention will
become apparent from the following detailed description considered
in conjunction with the accompanying drawings. It is to be
understood, however, that the drawings are designed solely for
purposes of illustration and not as a definition of the limits of
the invention, for which reference should be made to the appended
claims. It should be further understood that the drawings are not
necessarily drawn to scale and that, unless otherwise indicated,
they are merely intended to conceptually illustrate the structures
and procedures described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] An exemplary embodiment of the present invention is
explained in greater detail below with reference to the attached
schematic drawings, in which:
[0019] FIG. 1 is a block diagram showing the cooling circuit of the
present invention;
[0020] FIG. 2 to FIG. 9 are cross-sectional views of the rotary
side valve of the present inventions in eight different operating
positions; and
[0021] FIG. 10 is a block diagram schematically showing the
elements of the cooling circuit of the present invention.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
[0022] FIG. 1, which is a simplified block diagram, shows a cooling
circuit for an internal combustion engine in motor vehicles, having
a main cooling circuit and a secondary cooling circuit for a
retarder as a braking device of the motor vehicle, and having an
electrically actuated rotary slide valve for controlling both
cooling circuits, and
[0023] FIGS. 2 to 9 show a cross section through the housing of the
rotary slide valve with eight possible positions of the rotary
slide for controlling the main and secondary cooling circuits.
[0024] In FIG. 1, the cooling circuit of a liquid-cooled internal
combustion engine 1 for motor vehicles is shown in a highly
schematic form, having a main cooling circuit 2 and a secondary
cooling circuit 3 for a retarder 4 (shown in a purely schematic
way) of a braking device (continuous service brake), not shown
specifically, of the motor vehicle.
[0025] The main cooling circuit 2 consists essentially of a feed
line 5 leading from the internal combustion engine 1 to an
air/water heat exchanger or radiator 6 and of a return line 7 from
the radiator 6 to the internal combustion engine 1. A delivery pump
8 with a variably controllable delivery rate is arranged in the
return line 7.
[0026] A bypass line 9, which can be controlled by a rotary slide
valve 10 actuated by an electric stepper motor 20 (FIG. 10), is
inserted between the feed line 5 and the return line 7, downstream
of the delivery pump 8.
[0027] The main cooling circuit 2 is shown only to the extent
required for an understanding of the present invention. Additional
cooling circuit connections, e.g. an interior heating system of the
motor vehicle etc., are not shown.
[0028] The secondary cooling circuit 3 for cooling the retarder 4
(e.g. by a heat exchanger or by direct impingement) likewise has a
feed line 11 and a return line 12.
[0029] The feed line 11 is connected to a section 5a of the feed
line 5 of the main cooling circuit 2 upstream of the rotary slide
valve 10, and a restriction device 13 (e.g. a defined constriction)
can be provided in the feed line 5a between the connection point of
the two feed lines 5a, 11 and the rotary slide valve 10.
[0030] The delivery pump 8 and the stepper motor 20 of the rotary
slide valve 10 are controlled by an electronic control unit 14
(indicated in dashed lines), which brings about the variable output
of the delivery pump 8 by varying the rotational speed or volume
flow, for example, and effects the setting of the rotary slide
valve 10 to the operating positions described below. If
appropriate, the control unit 14 can also control an electric
radiator fan 16 on the radiator 6.
[0031] For this purpose, the data from temperature sensors T (not
shown), e.g. in the feed lines 5, 12, on load states L of the
internal combustion engine (e.g. traction or overrun mode), on the
operating state R of the retarder 4 etc. are detected and processed
for control purposes in the control unit 14.
[0032] FIGS. 2 to 9 show a cross section through the housing 10a of
the rotary slide valve 10, in which the crescent-shaped rotary
slide 10b is rotatably mounted. The rotary slide 10b, which is
sealed off from the outside, can be adjusted by the stepper motor
20 (FIG. 10) to the positions described below, varying from zero
degrees (FIG. 2) to 315 degrees (FIG. 9), for example.
[0033] Arranged on the housing 10a are three connection stubs,
which, as can be seen, are offset over the circumference, branch
off radially and adjoin throughflow openings which are blocked or
exposed to a greater or lesser extent by the rotary slide 10b.
Section 5a of the feed line 5, the onward-leading feed line section
5b and the bypass line 9 (each indicated by arrows) are connected
to the connection stubs.
[0034] Another connection stub 15 of the return line 12 is aligned
coaxially with the axis of rotation of the rotary slide 10b, and
the throughflow opening thereof is continuously open or, depending
on the position of the rotary slide, connected to one or two of the
other three throughflow openings.
[0035] In the zero degrees starting position of the rotary slide
10b (FIG. 2), the throughflow openings of the feed section 5a of
the feed line 5 and of the bypass line 9 are fully open.
[0036] The throughflow opening of the onward-leading feed line
section 5b is closed. This position corresponds to a cold start of
the internal combustion engine 1.
[0037] In this operating position, cooling fluid is recirculated
from the internal combustion engine 1, via the bypass line 9, the
delivery pump 8 and the remaining section of the return line 7,
back to the internal combustion engine 1. The radiator 6 is
decoupled, and therefore there is no flow through it.
[0038] The secondary cooling circuit 3 containing the retarder 4 is
likewise decoupled, owing to the higher flow resistance thereof,
although a low minimum flow rate can be set by the restriction 13,
if appropriate.
[0039] The division of the flow of cooling fluid is as follows, for
example:
[0040] Radiator 6--0%;
[0041] Bypass line 9--100%;
[0042] Retarder 4--0%;
[0043] Output of the delivery pump 8 reduced or even briefly
switched off.
[0044] FIG. 3 shows the operating position of the rotary slide 10b
as the internal combustion engine 1 increasingly warms up, in which
the throughflow opening of feed line section 5a is fully open and
the throughflow openings of feed line section 5b and of the bypass
line 9 are partially open, and the radiator 6 is thus connected
into the circulation of cooling fluid, accounting for about 50%
thereof. Due to the higher flow resistance of the secondary cooling
circuit 3, the retarder 4 remains decoupled as before, without
alteration.
[0045] As soon as the internal combustion engine 1 has reached the
operating temperature thereof, the rotary slide 10b is adjusted by
the stepper motor 20 to the operating position illustrated in FIG.
4, in which the bypass line 9 is closed and feed line section 5b
leading to the radiator 6 and feed line section 5a of the feed line
5 are fully open. For the reasons mentioned above, the retarder 4
remains decoupled. The output of the delivery pump 8 may already be
at an increased level.
[0046] In FIG. 5, the rotary slide 10b has been adjusted to a
position in which the throughflow opening leading to feed line
section 5b is still fully open but the throughflow opening of feed
line section 5a has been partially closed. The output of the
delivery pump 8 may have increased further.
[0047] This has the effect that the delivery pump 8 draws in
cooling fluid both via feed line section 5b of the main cooling
circuit 2 and via the feed line 11 of the secondary cooling circuit
3 and that both circuits 1 and 2 are coupled. This may be the case,
for example, when the retarder 4 is in braking mode and the
internal combustion engine 1 is relatively hot.
[0048] In the operating position of the rotary slide 10b shown in
FIG. 6, the throughflow opening of the bypass line 9 remains
closed, and the connection of feed line section 5a of the feed line
5 is also closed. The delivery pump 8 is switched to full
capacity.
[0049] Consequently, both cooling circuits 2 and 3 are fully
included in the circulation of cooling fluid and are switched to
full cooling capacity. The flow of cooling fluid flows via feed
line section 5a of feed line 5, feed line 11, the retarder 4, the
return line 12, feed line section 5b of the main cooling circuit,
the radiator 6 etc.
[0050] If the temperature T of the internal combustion engine 1
decreases, e.g. during a prolonged overrun phase of the motor
vehicle with the internal combustion engine 1 switched off, the
rotary slide 10b can be adjusted to an operating position in
accordance with FIG. 7, in which feed line section 5a remains
closed but the throughflow opening for the bypass line 9 is
partially open. The result is that, while there is still full flow
through the retarder 4, the flow through the internal combustion
engine 1 is reduced.
[0051] In the case of a prolonged overrun phase, with the internal
combustion engine 1 possibly cooling down further, this state can
be intensified, in accordance with FIG. 8, in such a way that, with
the throughflow openings of feed line section 5a and of feed line
section 5b closed and with the throughflow opening of the bypass
line 9 open, there continues to be full flow through the retarder
4, the throughput of cooling fluid taking place via the feed line
11 of the secondary cooling circuit 3, the retarder 4, the return
line 12 thereof, the bypass line 9, the delivery pump 8 and the
upstream return line 7. The retarder 4 thus additionally brings
about heating or temperature stabilization of the internal
combustion engine 1 while the radiator 6 is decoupled.
[0052] Finally, in the operating position of the rotary slide 10b
shown in FIG. 9, the throughflow opening of the bypass line 9
remains fully open and that of feed line section 5b remains fully
closed, while the throughflow opening of feed line section 5a of
the feed line 5b is partially open. As a result, the cooling
capacity for the retarder 4 is reduced and, if appropriate, the
output of the delivery pump 8 can also be throttled back.
[0053] The rotary slide valve 10 is not restricted to the
embodiment illustrated.
[0054] Thus, instead of a stepper motor 20 that can be adjusted in
both directions of rotation, it is also possible to provide some
other electric, mechanical, pneumatic, hydraulic or magnetic
actuating system.
[0055] The rotary slide 10b can be preloaded into an operating
position, e.g. that shown in FIG. 6, by resilient means (e.g. leg
springs 22 in FIG. 10), which move said rotary slide automatically
into this position if the electric actuating system fails and hold
it there. This ensures that both cooling circuits 2, 3 are in
service and that impermissible overheating cannot occur.
[0056] Moreover, the rotary slide valve 10 can be provided with at
least one position sensor, e.g. a rotation angle sensor 21, which
is connected to the control unit 14 in order in this way to
electronically assure the operation of the rotary slide 10b in a
feedback control system.
[0057] In addition to the functions described of the rotary slide
valve 10, the retarder 4 can be activated in a heating function for
the internal combustion engine 1 and the secondary cooling circuit
3 of said retarder can be connected temporarily to the bypassed
main cooling circuit 2 by the rotary slide valve 10 (operating
position of the rotary slide 10b as shown in FIG. 8). The essential
difference here is that the internal combustion engine 1 is under
power and is to be operated with a higher load requirement in order
to overcome the input braking power. This represents a particularly
effective heating phase for the internal combustion engine 1.
[0058] If appropriate, the delivery pump 8 and the rotary slide
valve 10 can be arranged in a common housing 23 with an integrated
bypass line 9, thereby reducing the outlay in terms of construction
and creating a particularly compact design which is advantageous in
terms of assembly.
[0059] In addition to the illustrated operating positions of the
rotary slide 10b in FIGS. 2 to 9, it is also possible for
additional intermediate positions of the rotary slide 10b to be
selected in an infinitely variable manner by the stepper motor 20,
and this can be the case in both directions of rotation with
different switching sequences as compared with the above
description.
[0060] Thus, while there have shown and described and pointed out
fundamental novel features of the invention as applied to a
preferred embodiment thereof, it will be understood that various
omissions and substitutions and changes in the form and details of
the devices illustrated, and in their operation, may be made by
those skilled in the art without departing from the spirit of the
invention. For example, it is expressly intended that all
combinations of those elements and/or method steps which perform
substantially the same function in substantially the same way to
achieve the same results are within the scope of the invention.
Moreover, it should be recognized that structures and/or elements
and/or method steps shown and/or described in connection with any
disclosed form or embodiment of the invention may be incorporated
in any other disclosed or described or suggested form or embodiment
as a general matter of design choice. It is the intention,
therefore, to be limited only as indicated by the scope of the
claims appended hereto.
* * * * *