U.S. patent application number 14/222624 was filed with the patent office on 2014-07-24 for camshaft device of a motor vehicle internal combustion engine.
This patent application is currently assigned to DAIMLER AG. The applicant listed for this patent is DAIMLER AG. Invention is credited to Thomas STOLK, Alexander VON GAISBERG-HELFENBERG.
Application Number | 20140202410 14/222624 |
Document ID | / |
Family ID | 46801430 |
Filed Date | 2014-07-24 |
United States Patent
Application |
20140202410 |
Kind Code |
A1 |
STOLK; Thomas ; et
al. |
July 24, 2014 |
CAMSHAFT DEVICE OF A MOTOR VEHICLE INTERNAL COMBUSTION ENGINE
Abstract
In a camshaft adjusting device of a motor vehicle internal
combustion engine which has an electromagnetic braking unit that
includes a stationary actuator having a first braking surface and
an axially spaced second braking surface which is movable relative
to the first braking surface, the braking unit further includes a
brake disk which is functionally separate from the stationary
actuator and is at least partially situated between the spaced
braking surfaces of the actuator and connected to an adjusting
input of the camshaft adjusting device.
Inventors: |
STOLK; Thomas; (Kirchheim,
DE) ; VON GAISBERG-HELFENBERG; Alexander; (Beilstein,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DAIMLER AG |
Stuttgart |
|
DE |
|
|
Assignee: |
DAIMLER AG
Stuttgart
DE
|
Family ID: |
46801430 |
Appl. No.: |
14/222624 |
Filed: |
March 22, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/EP2012/003697 |
Sep 4, 2012 |
|
|
|
14222624 |
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Current U.S.
Class: |
123/90.17 |
Current CPC
Class: |
F01L 1/352 20130101;
F01L 1/344 20130101 |
Class at
Publication: |
123/90.17 |
International
Class: |
F01L 1/344 20060101
F01L001/344 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 14, 2011 |
DE |
10 2011 116 164.7 |
Claims
1. A camshaft adjusting device of a motor vehicle internal
combustion engine having at least one electromagnetically actuated
braking unit (10) that includes at least one stationary actuator
(11) having at least a first braking surface (12) and a second
braking surface (13) which is movable relative to the first braking
surface (12), and a brake disk (14) which is functionally separate
from the actuator (11) and at least partially situated between the
first and second braking surfaces (12, 13) of the actuator (11) and
connected to an adjusting input (15) of the camshaft adjusting
device.
2. shaft adjusting device according to claim 1, wherein the brake
disk (14) has a density less than 5 g/cm.sup.3.
3. The camshaft adjusting device according to claim 1, wherein the
brake disk (14) is of a paramagnetic design.
4. The camshaft adjusting device according to claim 1, including a
summation gear (16) having a sun wheel (17) to which the brake disk
(14) is fixedly connected for forming the adjusting input (15).
Description
[0001] This is a Continuation-In-Part application of pending
international patent application PCT/EP2012/003697 filed 2012 Sep.
4 and claiming priority of German patent application 10 2011 116
1647 filed 2011 Oct. 14.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a camshaft adjusting device of a
motor vehicle internal combustion engine with an electromagnetic
braking device for controlling the phase position of the
camshaft.
[0003] An electromagnetic camshaft adjusting device of a motor
vehicle internal combustion engine having a mechanical braking unit
is already known from DE 10 2008 050 824 A1. It includes a brake
disk which is part of the electromagnetic actuator of the braking
unit.
[0004] A mechanical camshaft adjusting device is known for example
from U.S. Pat. No. 6,457,446 B1, in which the function of the
actuator is independent of the brake disk.
[0005] The object of the invention in particular is to provide a
cost-effective camshaft adjusting device which has short adjustment
times.
SUMMARY OF THE INVENTION
[0006] In a camshaft adjusting device of a motor vehicle internal
combustion engine which has an electromagnetically actuated braking
unit that includes a stationary actuator having a first braking
surface and an axially spaced second braking surface which is
movable relative to the first braking surface, the braking unit
further includes a brake disk which is functionally separate from
the stationary actuator and is at least partially situated between
the spaced braking surfaces of the stationary actuator and
connected to an adjusting input of the camshaft adjusting
device.
[0007] The actuator and the brake disk may be optimized
independently of one another, so that the adjustment time needed
for the setting of the phase position of the camshaft of the motor
vehicle internal combustion engine is reduced. The necessary
installation space, weight, and/or energy consumption of the
camshaft adjusting device is also reduced, and costs are lowered.
The mass inertia is decreased by reducing the mass of the brake
disk, as a result of which the adjustment speed is increased. A
cost-effective camshaft adjusting device having short adjustment
times may thus be provided. A "stationary actuator" is understood
in particular to mean an actuator having a stationary housing. The
term "stationary" is understood in particular to mean fixed in
place, i.e., permanently installed, preferably with respect to a
housing of the motor vehicle internal combustion engine. The
stationary actuator preferably has no rotating components. A
"braking surface" is understood in particular to mean a surface of
the actuator that is provided for establishing a connection to the
brake disk with frictional engagement in order to supply a braking
torque. An "actuator" is understood in particular to mean a
component that has at least one movable actuating element which is
preferably situated so as to be displaceable relative to the
housing of the actuator. The actuator is preferably provided for
converting an electronic and/or electrical signal into a mechanical
movement of the actuating element. The actuating element is
advantageously provided for actuating the brake disk. The actuating
element is preferably directly in contact with the brake disk for
the actuation. "A brake disk and an actuator which are functionally
separate from one another" is understood in particular to mean that
the actuating element of the actuator and the brake disk are
separate from one another, as the result of which the actuator may
be operational without a brake disk. The word "provided" is
understood in particular to mean specially designed, equipped,
and/or situated.
[0008] With the actuator having an electromagnetic design, a
particularly advantageous camshaft adjusting device may be realized
which has a short magnetic circuit, as the result of which the
camshaft adjusting device has low energy consumption and a rapid
response to magnetic energization. In addition, dead time of the
camshaft adjusting device may be reduced by a functional separation
of the electromagnetic actuator and the brake disk, so that the
adjustment times may be shortened. In addition, as a result of the
functional separation, a ferromagnetic design of the brake disk may
be dispensed with, thus allowing the brake disk to be optimized
with regard to weight, size, and/or the like. An "electromagnetic
actuator" is understood in particular to mean an actuator which has
at least one electromagnet that is provided for displacing the
actuating element.
[0009] In particular, it is advantageous for the brake disk to have
a density of less than 5 g/cm.sup.3, so that an advantageous brake
disk having low mass inertia may be provided.
[0010] Furthermore, it is advantageous for the brake disk to be
paramagnetic. A particularly advantageous brake disk may thus be
provided.
[0011] In addition, it is proposed that the camshaft adjusting
device includes a summation gear which has a sun wheel, for
example, to which the brake disk is fixedly connected for forming
the adjusting input. A phase position between a crankshaft and a
camshaft may thus be set in a particularly advantageous manner. A
"summation gear" is understood in particular to mean a gear that
has at least one planet wheel which is connected to a planet
carrier and which in the radial direction is outwardly in meshed
connection with an internal gear, and in the radial direction is
inwardly in meshed connection with the sun wheel. The planet
carrier is preferably connected to the crankshaft in a
torque-transmitting manner, and the internal gear is preferably
connected to the camshaft in a torque-transmitting manner.
[0012] The invention will become more readily apparent from the
following description of an exemplary embodiment of the invention
with reference to the accompanying drawings. The drawings, the
description, and the claims contain numerous features in
combination. Those skilled in the art will also advantageously
consider the features individually and combine them into further
meaningful combinations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 shows a perspective view of a camshaft adjusting
device; and
[0014] FIG. 2 shows the camshaft adjusting device in a sectional
illustration.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0015] FIGS. 1 and 2 show a camshaft adjusting device of a motor
vehicle internal combustion engine which is provided for adjusting
a phase position between a crankshaft of the motor vehicle internal
combustion engine, not illustrated here in greater detail, and a
camshaft 18 of the motor vehicle internal combustion engine.
[0016] For changing the phase position, the camshaft adjusting
device has a mechanical braking unit 10 which is provided for
supplying a braking torque in order to adjust the phase position.
The braking unit 10 has a stationary actuator 11, and a brake disk
14 which rotates during operation of the motor vehicle internal
combustion engine. The actuator 11 provides for engagement of the
brake disk 14 for generating a braking torque and thus for
adjusting the phase position. The actuator 11 and the brake disk 14
are functionally separate from one another, and are each designed
as independent components. The actuator 11 and the brake disk 14
are each independently optimized for their specific range of
tasks.
[0017] The actuator 11 has an electromagnetic design. The actuator
has a stationary housing 19, an actuating element 20 which is
movable relative to the housing 19, and a stationary electromagnet
21. The housing 19 has a multi-part design. The housing 19 is
mounted in a twist- and displacement-free manner. The housing is
fixedly connected to a housing, not illustrated here in greater
detail, of the motor vehicle internal combustion engine. The
housing 19 is fixedly connected to a cylinder head of the motor
vehicle internal combustion engine. The electromagnet 21 is fixedly
connected to the housing 19 of the actuator 11, and is provided for
displacing the actuating element 20. The actuating element 20 is
mounted in an axially displaceable and twist-free manner. The
actuating element is mounted so as to be displaceable parallel to a
rotational axis of the camshaft 18. The actuating element 20 and
the brake disk 14 are functionally separate from one another, and
have different designs. Upon energization, the electromagnet 21
presses the actuating element 20 against the brake disk 14 and
presses the brake disk 14 against the housing 19, thus generating
the braking torque. In the absence of energization and thus in a
de-energized state of the electromagnet 21, the actuating element
20 and the brake disk 14, as well as the housing 19 and the brake
disk 14, in each case are separated by an air gap.
[0018] The actuator 11 has a first braking surface 12 and a second
braking surface 13 which are situated axially opposite one another
and separated at a distance from one another. The first braking
surface 12 is mounted in a twist- and displacement-free manner, and
the second braking surface 13 is mounted only in a twist-free
manner. The second braking surface 13 is axially displaceable
relative to the first braking surface 12. The second braking
surface 13 is axially displaceable relative to the housing 19. The
first braking surface 12 is formed by the stationary housing 19 of
the actuator 11, and the second braking surface 13 is formed by the
actuating element 20. The actuating element 20 has a brake lining
22 for forming the second braking surface 13. The brake lining 22
of the actuating element 20 forms the second braking surface 13.
The brake lining 22 is fixedly 22 connected to the actuating
element 20, and is adhesively bonded to the actuating element 20.
For generating the braking torque, the second braking surface 13
presses the brake disk 14 axially against the first braking surface
12 due to energization of the electromagnet 21, as the result of
which the braking surfaces 12, 13 are each connected to the brake
disk 14 via frictional engagement, and the brake disk 14 is
decelerated. In the de-energized state of the electromagnet 21, the
first braking surface 12 and the second braking surface 13 are each
separated from the brake disk 14 by an air gap. In principle, the
actuating element 20 and the brake lining 22 may also be formed
together as one piece. Of course, it is also conceivable for the
first braking surface 12 to likewise be formed by a brake lining
which is fixedly connected to the housing 19.
[0019] The brake disk 14 is partially situated between the braking
surfaces 12, 13. The outer periphery of the brake disk is partially
situated between the braking surfaces 12, 13. A portion of the
brake disk 14 is situated axially between the braking surfaces 12,
13. The brake disk 14 is designed as a rotating element, and
rotates when the motor vehicle internal combustion engine is in
operation. The brake disk 14 has a rotational axis that corresponds
to the rotational axis of the camshaft 18. The brake disk is
situated on a shaft 23 in a twist-free manner.
[0020] The brake disk 14 has a density less than 5 g/cm.sup.3, and
has a paramagnetic design. The brake disk is made of light alloy,
and does not have ferromagnetic properties. The brake disk 14 is
made of aluminum. The brake disk 14 also may have a brake lining,
not illustrated in greater detail here, which is fixedly connected
to the brake disk 14. The brake lining is adhesively bonded to the
brake disk 14. The brake lining is situated on both axial sides of
the brake disk 14, and in each case is provided for contacting the
corresponding braking surface 12, 13 of the actuator 11. The brake
lining is made of carbon fiber-reinforced plastic (CFRP). In
principle, the brake disk 14 and the brake lining may also be
formed together as one piece, as the result of which the brake disk
14 is made of carbon fiber-reinforced plastic.
[0021] The camshaft adjusting device has a summation gear 16 for a
torque-transmitting connection of the crankshaft to the camshaft
18. The summation gear 16 is designed as a three-shaft minus
summation gear. The summation gear is designed as a single-stage
planet wheel gear. The summation gear 16 has a sun wheel 17 which
is fixedly connected to the shaft 23, and thus fixedly connected to
the brake disk 14. The shaft 23 and the sun wheel 17 are formed
together as one piece. The sun wheel 17 is designed as an adjusting
input 15 of the summation gear 16. The brake disk 14 is thus
fixedly connected to the adjusting input 15 of the summation gear
16. For adjusting the phase position, the brake disk 14 is fixedly
connected to the adjusting input 15.
[0022] The summation gear 16 also has a planet carrier 25 which is
fixedly connected to a crankshaft sprocket 24 of the camshaft
adjusting device. The crankshaft sprocket 24 and the planet carrier
25 are formed together as one piece. The planet carrier 25 is
connected to the crankshaft in a torque-transmitting manner by
means of the crankshaft sprocket 24, and is driven by the
crankshaft. The crankshaft sprocket 24 is designed as a chain
wheel, and is connected to the crankshaft in a torque-transmitting
manner by means of a chain. The planet carrier 25 guides planet
wheels, which mesh with the sun wheel 17, around the rotational
axis of the camshaft 18. The planet carrier 25 is designed as an
input of the summation gear 16.
[0023] The summation gear 16 also has an internal gear 26. The
internal gear 26 is fixedly connected to the camshaft 18. The
camshaft 18 and the internal gear 26 are formed together as one
piece. The internal gear 26 drives the camshaft 18, and meshes with
the planet wheels of the summation gear 16. The internal gear 26 is
designed as an output of the summation gear 16.
List of Reference Numerals
[0024] 10 Braking unit [0025] 11 Actuator [0026] 12 Braking surface
[0027] 13 Braking surface [0028] 14 Brake disk [0029] 15 Adjusting
input [0030] 16 Summation gear [0031] 17 Sun wheel [0032] 18
Camshaft [0033] 19 Housing [0034] 20 Actuating element [0035] 21
Electromagnet [0036] 22 Brake lining [0037] 23 Shaft [0038] 24
Crankshaft sprocket [0039] 25 Planet carrier [0040] 26 Internal
gear
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