U.S. patent application number 11/891053 was filed with the patent office on 2008-01-10 for apparatus and method for coupling and decoupling actuating elements of a valve drive of an internal combustion engine.
Invention is credited to Alexander von Gaisberg-Helfenberg, Matthias Gregor, Jens Meintschel, Tilmann Romheld, Thomas Stolk.
Application Number | 20080006232 11/891053 |
Document ID | / |
Family ID | 36190472 |
Filed Date | 2008-01-10 |
United States Patent
Application |
20080006232 |
Kind Code |
A1 |
Gregor; Matthias ; et
al. |
January 10, 2008 |
Apparatus and method for coupling and decoupling actuating elements
of a valve drive of an internal combustion engine
Abstract
In a method and apparatus for coupling or decoupling two
actuating elements of a valve drive of an internal combustion
engine for operating a gas exchange valve, comprising a locking
element movable between two end positions for coupling the
actuating elements, an electromagnet for actuating the movable
locking element, a permanent magnet is associated with the armature
for holding the armature and the locking element in one end
position and means for biasing the armature and the locking element
in the opposite end position, the electromagnet is energizable in
one sense for moving the armature into one end position in which
the armature is retained by the permanent magnet with a force
greater than a counteracting force generated by the biasing means,
and in the opposite sense so as to generate a force exceeding that
of the permanent magnet for moving the armature in the opposite end
position, where it is retained by said biasing means.
Inventors: |
Gregor; Matthias;
(Stuttgart, DE) ; Meintschel; Jens; (Esslingen,
DE) ; Romheld; Tilmann; (Waiblingen, DE) ;
Stolk; Thomas; (Kirchheim, DE) ; Gaisberg-Helfenberg;
Alexander von; (Beilstein, DE) |
Correspondence
Address: |
KLAUS J. BACH & ASSOCIATES;PATENTS AND TRADEMARKS
4407 TWIN OAKS DRIVE
MURRYSVILLE
PA
15668
US
|
Family ID: |
36190472 |
Appl. No.: |
11/891053 |
Filed: |
August 8, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/EP2006/000492 |
Jan 20, 2006 |
|
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|
11891053 |
Aug 8, 2007 |
|
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Current U.S.
Class: |
123/90.15 |
Current CPC
Class: |
F01L 13/0036 20130101;
F01L 1/185 20130101; H01F 7/122 20130101; F01L 2001/186 20130101;
F01L 2820/031 20130101; H01F 7/1615 20130101 |
Class at
Publication: |
123/090.15 |
International
Class: |
F01L 1/34 20060101
F01L001/34 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 10, 2005 |
DE |
10 2005 006 056.0 |
Claims
1. A method for coupling or decoupling two actuating elements (2,
3) of a valve drive of an internal combustion engine for operating
a gas exchange valve (1), comprising a locking element (5) movable
between two end positions for coupling the actuating elements (2,
3), an electromagnet (9) for actuating the movable locking element
(5) and including a coil (9a) and a yoke (9b) interacting with an
armature (10) which is operatively connected to the locking element
(5), a permanent magnet (15) associated with the armature (10) for
holding the armature (10) and the locking element (5) in one end
position and means (11) for biasing the armature (10) and the
locking element in the opposite end position, said method
comprising the steps of: energizing the coil (9a) in one sense for
moving the armature into one end position in which the armature is
retained by said permanent magnet with a force greater than a
counteracting force generated by the biasing means (11), and
energizing the coil (9a) in the opposite sense for generating a
force exceeding that of the permanent magnet (15) for moving the
armature (10) in the opposite end position, where it is retained by
said biasing means (11).
2. A method as claimed in claim 1, wherein, after the energization
by the permanent magnetic effect has been switched off, the
armature (10) retains at least one of its positions assumed as a
result of preceding energization of the electro-magnet (9).
3. A method as claimed in claim 1, wherein the armature comprises a
permanently magneticeable material and the armature is permanently
magnetized in one sense by energization of the electromagnet
(9).
4. An apparatus for coupling or decoupling two actuating elements
(2, 3) of a valve drive of an internal combustion engine for
optionally operating a gas exchange valve (1), comprising a locking
element (5) movable two end positions for coupling the actuating
elements (2, 3), an electromagnet (9) for actuating the movable
locking element (5) and including a coil (9a) and a yoke (9b)
interacting with an armature (10) which is part of the locking
element (5), a permanent magnet (15) associated with the armature
(10) for holding the armature (10) and the locking element (5) in
one end position and means (11) for biasing the armature (10) and
the locking element in the opposite end position, said coil (9a)
when energized in one sense moving the armature into one end
position in which the armature is retained by said permanent magnet
(15) with a force greater than a counteracting force generated by
the biasing means (11), and the coil (9a) when energized in the
opposite sense generating a force exceeding that of the permanent
magnet for moving the armature in the opposite end position, where
it is retained by said biasing means (11).
5. The apparatus as claimed in claim 4, wherein the means (11) for
biasing the armature (10) in the opposite end position is a spring
element (11).
6. The apparatus as claimed in claim 4, wherein, the permanent
magnetic force is generated by a permanent magnetic device (15)
attached to the armature (10).
7. The apparatus as claimed in claim 4, wherein the permanent
magnetic force is generated by the armature (10) being permanently
magnetized.
8. The apparatus as claimed in claim 4, wherein the actuating
elements comprise one of a camshaft adjuster, a supporting element,
an equalizing element, a cam follower and a camshaft.
Description
[0001] This is a Continuation-In-Part Application of pending
International Application Patent PCT/EP2006/000492 filed Jan. 20,
2006 and claiming the priority of German Patent Application 10 2005
006 056.0 filed Feb. 10, 2005.
BACKGROUND OF THE INVENTION
[0002] The invention relates to an apparatus and a method for
coupling or decoupling two actuating elements of a valve drive of
an internal combustion engine including an electro-magnetic looking
mechanism.
[0003] Such an apparatus for coupling and decoupling two actuating
elements of a valve gear of an internal combustion engine is known
from EP 0 833 041 A1. The apparatus has an electromagnet which is
mounted in the cylinder head of the internal combustion engine and
whose armature can assume two end positions. The armature actuates
a locking element which acts on the pivot lever. In order to
actuate the locking element, the electromagnet must be continuously
energized, resulting in an unnecessarily high consumption of
electrical energy.
[0004] It is the object of the present invention to provide a
method and an apparatus for coupling and decoupling two actuating
elements of a valve drive of an internal combustion engine which
operates with a high level of reliability and consumes a
significantly reduced amount of electrical energy.
SUMMARY OF THE INVENTION
[0005] In a method and apparatus for coupling or decoupling two
actuating elements of a valve drive of an internal combustion
engine for operating a gas exchange valve, comprising a locking
element movable between two end positions for coupling the
actuating elements, an electromagnet for actuating the movable
locking element, a permanent magnet is associated with the armature
for holding the armature and the locking element in one end
position and means for biasing the armature and the locking element
in the opposite end position, the electromagnet is energizable in
one sense for moving the armature into one end position in which
the armature is retained by the permanent magnet with a force
greater than a counteracting force generated by the biasing means,
and in the opposite sense so as to generate a force exceeding that
of the permanent magnet for moving the armature in the opposite end
position, where it is retained by said biasing means.
[0006] A significant advantage of the invention is provided by the
permanent magnetic force additionally acting on the armature. As a
result of this, after the energization by the armature is
discontinued the armature retains at least one of its positions in
which it is held by the permanent magnet or, respectively, the
spring. As a result the electromagnet does not have to be
continuously energized but needs to be energized only shortly for
moving the armature from one end position to the other.
[0007] The armature advantageously leaves its retained position as
a result of renewed energization of the electromagnet with reversed
polarization, which requires only a short current pulse.
[0008] A further advantage results from the fact that the permanent
magnetic force can be applied by the armature which has been
magnetized by the previous energization. This provides an apparatus
of simple design for coupling and decoupling two actuating elements
of a valve drive of an internal combustion engine with low power
consumption.
[0009] The permanent magnetic force is advantageously applied by a
permanent magnet which is arranged in the magnetic circuit, in
particular in the armature, which ensures a stable state in one
position over an extended time period.
[0010] The apparatus also includes a restoring spring for acting on
the armature, which restoring spring is capable of moving the
armature without using electrical energy.
[0011] In one end position of the armature the permanent magnetic
force is advantageously greater than the force of the restoring
spring, which ensures a stable position of the armature, and, in
the other end position, the permanent magnetic force is smaller
than the force of the restoring spring, so that the armature is
firmly held in the other end position by the spring.
[0012] The invention will become more readily apparent from the
following description of an exemplary embodiment with reference to
the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a partial sectional view of an apparatus which has
an element for coupling two actuating elements of a valve drive of
an internal combustion engine which act optionally on a gas
exchange valve, wherein an electromagnet interacts with an
armature,
[0014] FIG. 2 is a sectional view of the apparatus, wherein the
armature is in a first end position, and
[0015] FIG. 3 is a sectional view of the apparatus, wherein the
armature is in a second end position.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0016] The invention resides in an apparatus for coupling and
decoupling two actuating elements 2, 3 of a valve drive of an
internal combustion engine which actuating elements act optionally
on a gas exchange valve 1, wherein camshaft adjusters, camshafts,
equalizing elements, supporting elements or cam followers, for
example actuating levers or bucket tappets, can be provided as
actuating elements 2, 3. An apparatus according to the invention
with switchable actuating levers 2, 3 is disclosed in the following
figures.
[0017] FIG. 1 shows parts of the valve gear for actuating the at
least one gas exchange valve 1 of the internal combustion engine
having an inner lever 2 and an outer lever 3. The inner lever 2 is
mounted so as to be pivotable with its first end about a shaft 4,
with the shaft 4 being supported on the outer lever 3 and, when
locked, is supported with its second end on an element 5 of the
apparatus for coupling the inner lever 2 and outer lever 3. In the
case of unlocking, the inner lever 2 acts on an idle travel spring
14.
[0018] The outer lever 3 has for example two arms 7 which are
provided, for example, with cam surfaces 6 on which at least one
cam 18 with a small stroke can act. The arms 7 of the outer lever 3
surround the inner lever 2 which can be actuated by at least one
cam 17 with a large stroke. The outer lever 3 is supported at one
end at least indirectly on a component 8 of the internal combustion
engine, it being possible for the component 8 to be a valve
play-adjusting element, a housing part of the internal combustion
engine or a bearing point. At the other end it acts on the gas
exchange valve 1.
[0019] The system is therefore comprised of two levers, that is,
the outer lever 3, which is supported in the present case on the
hydraulic valve play-adjusting element 8 and acts on the valve stem
la of the gas exchange valve 1 which is to be actuated, and the
inner lever 2 which is mounted on the outer lever 3.
[0020] In order to be able to actuate the gas exchange valve 1
alternatively also by means of the inner lever 2 or only by means
of the outer lever 3 and thus to bring about different valve
strokes, the element 5 is provided. The element 5 can be acted on
by an electromagnet 9 in a locking direction 12 and an unlocking
direction 13, said electromagnet 9 being composed of a coil 9a, a
yoke 9b and an armature 10. The armature 10 is operatively
connected to the element 5, i.e. in the present exemplary
embodiment the armature 10 is connected to the element 5. A spring
element 11 additionally acts on the element 5 in the locking
direction 12. As a result, the element 5 can be pushed in the
locking direction 12 by the spring element 11 and/or the armature
10 of the electromagnet 9, and can be pushed in the unlocking
direction 13 by the armature 10 which acts as a restoring
element.
[0021] In order to provide an apparatus for coupling and decoupling
two actuating elements of a valve gear of an internal combustion
engine which operates with a high level of operational reliability
and significantly reduced electrical energy consumption, the
invention proposes that the apparatus have a permanent magnetic
device 15 for acting on the armature 10. In the present example,
the permanent magnetic device 15 is a component of the armature 10,
which is otherwise fabricated from nonpermanent magnetic material,
or the permanent magnetic force is applied by the armature 10 which
has been magnetized by preceding energization.
[0022] FIG. 2 shows the element 5 of the apparatus in the locked
position. The electromagnet 9 is switched to a deenergized setting,
as a result of which the spring element 11 pushes the armature 10
at least partially out of the electromagnet 9 in the locking
direction 12 until the element 5 bears against a stop 16 which is
preferably provided on the outer lever 3. This position is stable
without energization of the electromagnet 9 since the force of the
spring element 11 is higher than the effect of the permanent
magnetic device 15 which is reduced owing to the large distance
between the armature 10 and the yoke 9b. As a result, the inner
lever 2 is connected in a positively locking fashion to the outer
lever 3, i.e. the cam 17 generating a large stroke acts via the
inner lever 2 on the outer lever 3 which then actuates the gas
exchange valve 1, while the cam 18 generating the small stroke
operates in idle.
[0023] FIG. 3 shows the element 5 of the apparatus in the unlocked
position. In order to unlock the actuating elements 2, 3, the
electromagnet 9 is briefly energized, so that the armature 10 is
pulled into a recess 19 which is formed by the yoke 9b. As a
result, the element 5 which is connected to the armature 10 is
pulled away from under the inner lever 2 by said armature against
the force of the spring element 11. As a result, the inner lever 2
is deactivated, i.e. the cam 18 with a small stroke acts on the
outer lever 3 which then actuates the gas exchange valve 1, with
the inner lever 2, on which the cam 17 with a large stroke acts,
merely carrying out an oscillating idle movement on the outer lever
3.
[0024] As already mentioned above, the armature 10 is pulled into
the recess 19 by brief energization of the electromagnet 9. Because
of the small distance between the armature 10 and the recess 19,
the effect of the permanent magnetic device 15 is greater than the
force of the spring element 11, for which reason the armature 10
also remains in this position without energization of the
electromagnet 9, which results in significantly reduced consumption
of electrical energy.
[0025] In order to bring about the locked position illustrated in
FIG. 2, the electromagnet 9 is briefly energized with reversed
polarity.
* * * * *