U.S. patent application number 12/944341 was filed with the patent office on 2011-05-19 for camshaft insert.
This patent application is currently assigned to HYDRAULIK-RING GMBH. Invention is credited to Marc Hohmann, Andreas Knecht, Dietmar Schulze, Andre Selke.
Application Number | 20110114047 12/944341 |
Document ID | / |
Family ID | 43640082 |
Filed Date | 2011-05-19 |
United States Patent
Application |
20110114047 |
Kind Code |
A1 |
Hohmann; Marc ; et
al. |
May 19, 2011 |
CAMSHAFT INSERT
Abstract
The invention relates to a camshaft insert for a camshaft, which
can be, in particular, a composite camshaft. In this case, the
camshaft insert bears an oscillating motor adjuster. An accumulator
that can be loaded by means of a spring force is disposed inside
camshaft insert. Alternatively, the accumulator can also be
disposed in the camshaft.
Inventors: |
Hohmann; Marc;
(Marktheidenfeld, DE) ; Schulze; Dietmar;
(Giessen, DE) ; Knecht; Andreas; (Kusterdingen,
DE) ; Selke; Andre; (Naumburg, DE) |
Assignee: |
HYDRAULIK-RING GMBH
Marktheidenfeld
DE
|
Family ID: |
43640082 |
Appl. No.: |
12/944341 |
Filed: |
November 11, 2010 |
Current U.S.
Class: |
123/90.15 |
Current CPC
Class: |
F01L 2001/0475 20130101;
F01L 2001/34433 20130101; F01L 2001/34446 20130101; F01L 1/3442
20130101; F01L 1/047 20130101 |
Class at
Publication: |
123/90.15 |
International
Class: |
F01L 1/344 20060101
F01L001/344 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 13, 2009 |
DE |
10 2009 052 841.5 |
Claims
1. A camshaft insert for a camshaft, which is joined in a
rotation-resistant manner to a rotor of an oscillating motor
adjuster, wherein an accumulator that can be loaded by means of a
spring force is disposed inside the camshaft insert.
2. The camshaft insert according to patent claim 1, further
comprising a hydraulic part of a valve disposed radially inside the
rotor.
3. The camshaft insert according to patent claim 2, wherein the
hydraulic part is disposed flush relative to the accumulator.
4. The camshaft insert according to claim 2, wherein the
accumulator is separated from the hydraulic part by means of a
wall, on which a first end of a screw-type pressure spring is
supported, at least indirectly, a second end of the spring being
supported on a valve piston.
5. The camshaft insert according to patent claim 4, further
comprising an electromagnetic actuator supported on one side of a
valve piston and the second end of the screw-type pressure spring
is supported on the other side of the valve piston, whereby fluid
is introduced into the valve piston via a storage connection (S)
coming from the accumulator, the fluid being able to be divided
onto two work ports (A, B) alternately via two output edges by
means of an overlap control, and the work ports leading into
opposite-working pressure chambers on both sides of at least one
blade of the rotor.
6. The camshaft insert according to claim 1, wherein the
accumulator has a pressurized space into which the fluid is
introduced from a pressurized connection (P).
7. The camshaft insert according to patent claim 6, wherein the
accumulator is bounded by an axially movable hydraulic piston,
which is supported thereon at an axial part attached to the
camshaft on a side pointing toward pressurized space by means of a
screw-type pressure spring.
8. The camshaft insert according to patent claim 7, wherein the
fluid is introduced into the accumulator from a channel to which is
introduced the fluid from an annular groove, which is provided in a
cylinder head part.
9. The camshaft insert according to claim 5, wherein a tank
connection (T2) lies axially between a pressurized connection (P)
leading into a pressurized space of the accumulator and the work
ports (A, B).
10. The camshaft insert according to claim 1, wherein: the camshaft
comprises a hollow camshaft; and the camshaft insert has an inner
pin, which is pressed into the hollow camshaft.
11. The camshaft insert according to patent claim 10, wherein the
camshaft comprises a composite camshaft.
12. The camshaft insert according to patent claim 11, wherein the
camshaft insert and a threaded pin for fastening the rotor in a
rotation-resistant manner on the camshaft are designed in one
piece.
13. The camshaft insert according to claim 1, wherein the camshaft
insert has a threaded pin onto which is screwed a nut, which braces
the rotor in a rotation-resistant manner against a shoulder of the
camshaft insert.
14. The camshaft insert according to claim 1, further comprising a
non-return valve positioned in the hydraulic flow between an oil
pump and the accumulator.
15. A camshaft insert for a camshaft, which is joined in a
rotation-resistant manner to a rotor of an oscillating motor
adjuster, wherein an accumulator that can be loaded by means of a
spring force is disposed in the camshaft.
16. The camshaft insert according to patent claim 15, further
comprising a hydraulic part of a valve disposed radially inside the
rotor.
17. The camshaft insert according to patent claim 16, wherein the
hydraulic part is disposed flush relative to the accumulator.
18. The camshaft insert according to claim 16, wherein the
accumulator is separated from the hydraulic part by means of a
wall, on which a first end of a screw-type pressure spring is
supported, at least indirectly, a second end of the spring being
supported on a valve piston.
19. The camshaft insert according to patent claim 18, further
comprising an electromagnetic actuator supported on one side of a
valve piston and the second end of the screw-type pressure spring
is supported on the other side of the valve piston, whereby fluid
is introduced into the valve piston via a storage connection (S)
coming from the accumulator, the fluid being able to be divided
onto two work ports (A, B) alternately via two output edges by
means of an overlap control, and the work ports leading into
opposite-working pressure chambers on both sides of at least one
blade of the rotor.
20. The camshaft insert according to claim 15, wherein the
accumulator has a pressurized space into which the fluid is
introduced from a pressurized connection (P).
21. The camshaft insert according to patent claim 20, wherein the
accumulator is bounded by an axially movable hydraulic piston,
which is supported thereon at an axial part attached to the
camshaft on a side pointing toward pressurized space by means of a
screw-type pressure spring.
22. The camshaft insert according to patent claim 21, wherein the
fluid is introduced into the accumulator from a channel to which is
introduced the fluid from an annular groove, which is provided in a
cylinder head part.
23. The camshaft insert according to claim 19, wherein a tank
connection (T2) lies axially between a pressurized connection (P)
leading into a pressurized space of the accumulator and the work
ports (A, B).
24. The camshaft insert according to claim 15, wherein: the
camshaft is a hollow camshaft; and the camshaft insert has an inner
pin, which is pressed into the hollow camshaft.
25. The camshaft insert according to patent claim 24, wherein the
camshaft comprises a composite camshaft.
26. The camshaft insert according to patent claim 25, wherein the
camshaft insert and a threaded pin for fastening the rotor in a
rotation-resistant manner on the camshaft are designed in one
piece.
27. The camshaft insert according to claim 15, wherein the camshaft
insert has a threaded pin onto which is screwed a nut, which braces
the rotor in a rotation-resistant manner against a shoulder of the
camshaft insert.
28. The camshaft insert according to claim 15, further comprising a
non-return valve positioned in the hydraulic flow between an oil
pump and the accumulator.
Description
[0001] This application claims the benefit of German patent
application no. DE 10 2009 052 841.5-13 filed on Nov. 13, 2009
which is incorporated herein and made a part hereof by reference
for all purposes.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a camshaft insert for a camshaft,
which insert is joined in a rotation-resistant manner to a rotor of
an oscillating motor adjuster.
[0003] An electrohydraulic valve for an oscillating motor adjuster
of a camshaft is already known from DE 100 50 225 A1. This valve is
inserted into a valve housing in which channels having work ports
A, B are provided, which lead to the pressurized spaces of the
oscillating motor adjuster. A tappet of the electrohydraulic valve
rests against a piston rod, which is joined in one piece with a
piston. This piston can move against a spring force within a
pressurized space in the valve housing.
[0004] DE 10 2004 038 252 A1 shows an oscillating motor adjuster
with a so-called central valve. In a central valve, the valve for
actuating the oscillating motor adjuster is disposed radially
inside the rotor on the rotor hub thereof.
SUMMARY OF THE INVENTION
[0005] The object of the invention is to create an oscillating
motor adjuster in which an accumulator is provided in a
space-saving manner.
[0006] This object is accomplished according to the claimed
camshaft insert.
[0007] In accordance with the present invention, an accumulator is
integrated in a particularly advantageous manner in a camshaft
insert, which bears the rotor.
[0008] Alternatively, the accumulator can also be disposed in the
camshaft.
[0009] In one advantageous configuration of the invention, the
camshaft insert and a threaded pin are designed in one piece for
the rotation-resistant attachment of the rotor to the camshaft. In
this way, the camshaft insert can be designed with very thick
walls, whereby a lengthwise bore can be introduced into it. In
particular, this lengthwise bore can guide the hydraulic fluid, for
example motor oil, coming from the accumulator to the central
valve. The central valve can thus be designed so that hydraulic
fluid is introduced from the lengthwise bore via a small cross bore
into an annular groove in the valve piston that is bounded by
annular crosspieces. The output edges lie at these annular
crosspieces. If these annular crosspieces have the same outer
diameter, then the central valve is pressure-compensated.
[0010] In a particularly advantageous way, cross bores do not need
to lie in the force flow of the threaded connection so that high
axial forces can be transferred.
[0011] The construction presented according to the invention makes
it possible that the regions of the camshaft insert having cross
bores for the work ports A, B are kept free of tensile forces,
whereby these regions are only loaded with torsional forces when
tightening the nut.
[0012] In a further advantageous manner, a non-return valve can be
provided so that leakage losses are prevented at the rotary
leadthrough for the fluid (e.g., motor oil).
[0013] Additional advantages of the invention are apparent from the
patent claims, the description and the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will hereinafter be described in
conjunction with the appended drawing figures, wherein like
reference numerals denote like elements, and:
[0015] FIG. 1 shows the construction of a camshaft drive in a first
example embodiment; and
[0016] FIG. 2 shows schematically a camshaft drive in a second
example embodiment.
DETAILED DESCRIPTION
[0017] The ensuing detailed description provides exemplary
embodiments only, and is not intended to limit the scope,
applicability, or configuration of the invention. Rather, the
ensuing detailed description of the exemplary embodiments will
provide those skilled in the art with an enabling description for
implementing an embodiment of the invention. It should be
understood that various changes may be made in the function and
arrangement of elements without departing from the spirit and scope
of the invention as set forth in the appended claims.
[0018] FIG. 1 shows an example embodiment of a camshaft drive
having an oscillating motor adjuster 1, such as has already been
presented in DE 100 50 225 A1. In contrast to DE 100 50 225 A1, a
hydraulic part 2 of a valve 3 is designed as a central valve. The
oscillating motor adjuster 1 comprises a stator 4 driven by a
crankshaft or another camshaft via a gearing 48. For this purpose,
a chain, a toothed belt or another toothed gear engages in this
gearing 48. In addition, oscillating motor adjuster 1 comprises a
rotor 6, which is disposed so that it can it pivot relative to
stator 4. For this purpose, blades 49 of rotor 6 subdivide chambers
of stator 4 (which are not shown in more detail) into
opposite-working pressure chambers.
[0019] The camshaft drive comprises a camshaft 5, which is mounted
on both sides in camshaft bearings, which are not shown in further
detail. This camshaft 5 has cams (not shown in further detail),
with which cylinder valves of an internal combustion engine can be
actuated. Camshaft 5 is designed as a composite camshaft. In this
case, the basic unit of camshaft 5 is a hollow pipe, onto which the
cams are shrunk or press-fitted. In the end on the side of the
oscillating motor, a fitting piece 7 is machined in the inside
space of the hollow shaft that takes up an inner pin 8 of a
camshaft insert 9.
[0020] Outside camshaft 5, the camshaft insert 9 is shaped as a
rotor support 10, which has a larger diameter than inner pin 8. At
the rear end, camshaft insert 9 has a threaded pin 11, the threaded
diameter of which is smaller than the diameter of rotor support 10.
A nut 12, which braces rotor 6 in a rotation-resistant manner
against a shoulder 13 of rotor support 10, is screwed onto this
threaded pin 11. For this purpose, an annular projection 15 that
projects to the inside radially from a rotor hub 14 is braced
axially between nut 12 and shoulder 13 of camshaft insert 9. This
shoulder 13 forms the boundary between rotor support 10 and
threaded pin 11. Rotor hub 14 is placed on the back region of rotor
support 10.
[0021] In contrast, the front region of rotor support 10 projects
through a bearing piece 16 of a cylinder head part 17, which
supportively holds this rotor support 10. In this case, an annular
groove 18 is worked into cylinder head part 17, this groove being
introduced from an oil pump for motor oil, which is not shown in
more detail, so that this annular groove 18 forms a pressurized
connection P. A strip-shaped, no-return valve 50 is inserted into
this annular groove 18, which prevents motor oil from being able to
flow back into the oil pump as a consequence of camshaft
alternating torque. The pressurized motor oil is fed into a cross
bore 19 of rotor support 10 by this pressurized connection P. The
flow of motor oil is distributed from this cross bore 19 that
passes through onto an accumulator 20 and a lengthwise bore 21 in
rotor support 10 that leads to valve 3. This lengthwise bore 21 is
sealed at its end pointing toward the inside space of the engine by
means of a bead 22 that is pressed in.
[0022] Accumulator 20 is aligned coaxially to its central axis 23
in a front region of camshaft insert 9. A pressurized space 24 of
accumulator 20 is formed by a blind hole 25, which is worked into
camshaft insert 9 from the front. A hydraulic piston 26, which is
joined in a movement-resistant manner with a piston rod 27 in a
direction pointing away from pressurized space 24, is introduced in
an axially movable manner in this blind hole 25. This piston rod 27
projects with radial play through a ring 28, which is solidly
pressed into inner pin 8 in the entrance region of blind hole 25.
One end of a screw-type pressure spring 29 is supported on this
ring 28, and the other end thereof is supported on hydraulic piston
26. The radial play between piston rod 27 and ring 28 makes
possible the passage of air or motor oil, so that hydraulic piston
26 is freely movable without the circumstance that the volume that
is being displaced from a spring space results in flow resistances
that are too high. In this way, accumulator 20, that can be loaded
by means of a spring force, is formed.
[0023] A hydraulic part 2 is disposed flush with this accumulator
20 in camshaft insert 9. A separating wall 30 lies between
accumulator 20 and hydraulic part 2. One end of another screw-type
pressure spring 31 is supported on this separating wall 30, and the
other end thereof is supported at a bottom 32 of a valve piston 33.
For this purpose, this other end projects into a guide recess 34 of
valve piston 33 up to the base of this recess, in which lies bottom
32.
[0024] Valve piston 33 is guided axially in a central blind hole
35. Blind hole 35 opens up in the region of threaded pin 11. In
this case, the entrance region of this blind hole 35 forms the
first tank outlet T1.
[0025] Valve piston 33 has a wide annular groove 36, so that
annular crosspieces 37, 38, each of which forms output edges 39,
40, 41, 42 on both sides, remain on both side of annular groove 36.
Output edges 40, 41 that face each other thus serve for the run-in
to a work port A or B. Output edges 39, 42 facing away from each
other form the run-off to a tank outlet T1 or T2.
[0026] Motor oil can be introduced into annular groove 36 via a
cross bore 43. This cross bore 43 is provided in wall 44 of rotor
support 10 and thus forms the storage connection S. Cross bore 43
crosses lengthwise bore 21. In this way, storage connection S is
joined via the frontmost cross bore 19 with both pressurized space
24 as well as with pressurized connection P.
[0027] A space 45, which leads to the second tank outlet T2 via a
cross bore 46, is axially enclosed between valve piston 33 and
separating wall 30. This second tank outlet T2 lies axially between
cylinder head part 17 and oscillating motor adjuster 1. Further,
this second tank outlet T2 lies axially [0028] between storage
connection S, on the one hand, and [0029] the two work ports A, B
and the pressure connection P, on the other hand.
[0030] A tappet 47 of an electromagnetic linear actuator, which is
shown by dashes, but not in further detail, lies outside, i.e.,
projecting out from the entrance region, on valve piston 33.
[0031] If tappet 47 is maximally disengaged or moved out, then the
motor oil coming from annular groove 36 is guided via work port A
into the pressure chambers of oscillating motor adjuster 1, these
chambers being assigned to a first direction of rotation. In
contrast, the motor oil is guided out of the pressure chambers
assigned to the opposite direction of rotation to first tank outlet
T1 via the work port B. In this way, rotor 6 together with camshaft
5 turns opposite stator 4 in the first direction of rotation.
[0032] In contrast, if tappet 47 is maximally engaged or moved in,
then the motor oil coming from annular groove 36 is guided via work
port B into the pressure chambers of oscillating motor adjuster 1
assigned to the other direction of rotation. Likewise, the motor
oil is guided out of the pressure chambers assigned to this other
direction of rotation to second tank outlet T2 via the work port A.
In this way, rotor 6 together with camshaft 5 turns opposite stator
4 in the other direction of rotation.
[0033] In this way, the play between valve piston 33 and blind hole
35 is dimensioned in a ratio to the axial distances between work
ports A, B and output edges 39 to 42 such that in a central
position of valve piston 33, pressure is provided on the pressure
chambers assigned to both directions of rotation. In the central
position, consequently, the hydraulic pressure is controlled with a
slight overlap. Hydraulic piston 26 in accumulator 20 need not
absolutely have a piston rod 27. If the guide length of hydraulic
piston 26 is sufficient, the entire diameter can also be utilized
in ring 28 for a large flow volume.
[0034] Since the camshaft has a relatively slow speed, balancing
errors play a subordinate role. However, in order to reduce the
balancing error, the lengthwise bore and the cross bores in the
camshaft insert can be distributed around the periphery so that the
balancing error is only slight.
[0035] If an opening is provided in bottom 32 of valve piston 33,
then blind hole 35 can also be closed, so that the pressure relief
vis-a-vis the tank only occurs via the one tank outlet T2, which
thus forms the single tank outlet. In this case, the tappet
projects through a sealed opening in camshaft insert 9.
[0036] Hydraulic piston 26 can also be guided directly in camshaft
5, if the latter is designed with a hollow tube as the basic
unit.
[0037] Ring 28 may also be directly supported axially in camshaft
5.
[0038] Strip-shaped, non-return valve 50 may also be inserted into
an annular groove in camshaft insert 9. In this way, leakage losses
can be prevented from occurring at the transfer point from bearing
piece 16 to camshaft insert 9.
[0039] One possible embodiment of a strip-shaped, non-return valve
is shown in U.S. Pat. No. 7,600,531 B2.
[0040] FIG. 2 shows the hydraulic diagram of an example embodiment
of a camshaft insert 57 with integrated non-return valve 63 in an
alternative embodiment.
[0041] In this embodiment, the oscillating motor camshaft adjuster
51 is constructed analogously to the first embodiment discussed
above in connection with FIG. 1. However, in the FIG. 2 example
embodiment, the transfer point of the motor oil from a cylinder
head part 52 at an annular groove 53 is disposed axially between an
electromagnetic actuator 54 and the oscillating motor camshaft
adjuster 51. Camshaft insert 57 thus projects out as a pin 59 above
oscillating motor camshaft adjuster 51. In this way, pin 59 is
taken up in cylinder head part 52. A channel 61 coming from an oil
pump 60 leads into a bore 62, which guides the motor oil into
annular groove 53 of camshaft insert 57. From annular groove 53,
the motor oil is guided via non-return valve 63, on the one hand,
to an accumulator 58 and, on the other hand, to a valve piston
55.
[0042] Analogously to the first embodiment, this valve piston 55 is
supported axially on camshaft insert 57 by means of a screw-type
pressure spring 56. Valve piston 55 is also aligned flush relative
to accumulator 58, which, as is shown in FIG. 2, can be disposed
directly in camshaft insert 57. Alternatively, accumulator 58 can
also be disposed in the camshaft.
[0043] The described embodiments only involve exemplary
configurations. A combination of the described features for the
different embodiments is also possible. Additional features,
particularly those which have not been described, of the device
parts belonging to the invention can be derived from the geometries
of the device parts shown in the drawings.
List of Reference Symbols
[0044] 1 Oscillating motor camshaft adjuster [0045] 2 Hydraulic
part [0046] 3 Valve [0047] 4 Stator [0048] 5 Camshaft [0049] 6
Rotor [0050] 7 Fitting piece [0051] 8 Inner pin [0052] 9 Camshaft
insert [0053] 10 Rotor support [0054] 11 Threaded pin [0055] 12 Nut
[0056] 13 Shoulder [0057] 14 Rotor hub [0058] 15 Projection [0059]
16 Bearing piece [0060] 17 Cylinder head part [0061] 18 Annular
groove [0062] 19 Cross bore [0063] 20 Accumulator [0064] 21
Lengthwise bore [0065] 22 Bead [0066] 23 Central axis [0067] 24
Pressurized space [0068] 25 Blind hole [0069] 26 Hydraulic piston
[0070] 27 Piston rod [0071] 28 Ring [0072] 29 Screw-type pressure
spring [0073] 30 Separating wall [0074] 31 Screw-type pressure
spring [0075] 32 Bottom [0076] 33 Valve piston [0077] 34 Guide
recess [0078] 35 Blind hole [0079] 36 Annular groove [0080] 37
Annular crosspiece [0081] 38 Annular crosspiece [0082] 39 Output
edge [0083] 40 Output edge [0084] 41 Output edge [0085] 42 Output
edge [0086] 43 Cross bore [0087] 44 Wall [0088] 45 Space [0089] 46
Cross bore [0090] 47 Tappet [0091] 48 Gearing [0092] 49 Blade
[0093] 50 Non-return valve [0094] 51 Oscillating motor camshaft
adjuster [0095] 52 Cylinder head part [0096] 53 Annular groove
[0097] 54 Electromagnetic actuator [0098] 55 Valve piston [0099] 56
Screw-type pressure spring [0100] 57 Camshaft insert [0101] 58
Accumulator [0102] 59 Pin [0103] 60 Oil pump [0104] 61 Channel
[0105] 62 Bore [0106] 63 Non-return valve
* * * * *