U.S. patent application number 13/734724 was filed with the patent office on 2014-07-10 for valve seat insert.
This patent application is currently assigned to Ford Global Technologies, LLC. The applicant listed for this patent is FORD GLOBAL TECHNOLOGIES, LLC. Invention is credited to Chong Hsi Jack Chen, Jim Chern, Minghui Chien, Scott Michael DeRaad.
Application Number | 20140190441 13/734724 |
Document ID | / |
Family ID | 51019185 |
Filed Date | 2014-07-10 |
United States Patent
Application |
20140190441 |
Kind Code |
A1 |
Chern; Jim ; et al. |
July 10, 2014 |
VALVE SEAT INSERT
Abstract
Embodiments may provide a valve seat insert including a valve
seat face. A circumferential contact surface for contacting a
cylinder head may be located radially outside and at least
partially axially offset from the valve seat face. A discontinuity
may be located radially between the valve seat face and the
cylinder head and at least partially axially aligned with the valve
seat face.
Inventors: |
Chern; Jim; (Troy, MI)
; Chen; Chong Hsi Jack; (Bloomfield Hills, MI) ;
Chien; Minghui; (Farmington Hills, MI) ; DeRaad;
Scott Michael; (Ann Arbor, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FORD GLOBAL TECHNOLOGIES, LLC |
Dearborn |
MI |
US |
|
|
Assignee: |
Ford Global Technologies,
LLC
Dearborn
MI
|
Family ID: |
51019185 |
Appl. No.: |
13/734724 |
Filed: |
January 4, 2013 |
Current U.S.
Class: |
123/188.8 |
Current CPC
Class: |
F01L 3/22 20130101 |
Class at
Publication: |
123/188.8 |
International
Class: |
F01L 3/22 20060101
F01L003/22 |
Claims
1. A valve seat insert, comprising: a valve seat face; a
circumferential contact surface shaped to contact a cylinder head
located radially outside the valve seat face; and a gap radially
between the valve seat face and the circumferential contact surface
and at least partially axially aligned with the valve seat face,
the gap centrally located along an annular outward surface that
extends radially between the circumferential contact surface to the
valve seat face.
2. The valve seat insert of claim 1, wherein the gap has a
rectangular cross-section.
3. The valve seat insert of claim 2, wherein a valve seat insert
material deforms when the valve seat face is contacted by a valve
thereby at least partially closing the gap.
4. The valve seat insert of claim 2, wherein the gap is adjacent to
an inner surface of a counterbore in the cylinder head.
5. The valve seat insert of claim 1, wherein the gap is an annular
gap with a wedge shaped cross-section.
6. A valve seat insert, comprising: an annular-shaped body, the
body having a peripheral side-wall and an annular outward surface,
the outward surface having at least an inwardly angled inner
surface, and an outer surface perpendicular to a central axis of
the body, the outer surface including a gap that is spaced away and
does not intersect the inwardly angled inner surface, and which is
axially aligned with a valve seat face.
7. The valve seat insert of claim 6 wherein the gap has a
cross-section of an arch.
8. The valve seat insert of claim 6 wherein the gap forms an indent
having a rectangular cross-section in the outer surface.
9. The valve seat insert of claim 8 wherein the indent traverses
completely around the outer surface around the central axis of the
body.
10. A valve seat insert, comprising: an outer surface having a
substantially cylindrical portion configured to fit within and to
make contact with a counterbore within a cylinder head and a
frusto-conical portion configured to be spaced apart from the
counterbore, the frusto-conical portion positioned between a gap
and the outer surface.
11. The valve seat insert of claim 10, further comprising a center
bore through the insert, and a valve seat face formed in the center
bore substantially axially aligned with the frusto-conical
portion.
12. The valve seat insert of claim 10, wherein the frusto-conical
portion forms a wedge shaped gap between the outer surface and the
counterbore.
13. The valve seat insert of claim 12, wherein the valve seat
insert includes a central axis and wherein the gap includes a
maximum radial thickness of between approximately 0.1 mm and 1.0
mm.
14. The valve seat insert of claim 10, wherein the frusto-conical
portion includes an edge spaced from the substantially cylindrical
portion wherein the edge is nominally located from an inner surface
of the counterbore approximately 0.1 mm to 1.0 mm.
15. The valve seat insert of claim 10, wherein the frusto-conical
portion includes an edge spaced from the substantially cylindrical
portion wherein the edge is nominally located from an inner surface
of the counterbore approximately 0.3 mm.
16. The valve seat insert of claim 10, wherein the gap is
substantially closed when a valve makes forcible contact with a
valve seat, and wherein valve seat insert is an elastomer.
17. (canceled)
18. A valve seat arrangement comprising: a counterbore in a
cylinder head having an inner surface; a valve seat insert fitted
into the counterbore having an outer surface, the outer surface
including: a first portion contacting the counterbore inner
surface, and a second portion spaced from the counterbore inner
surface; and a valve seat face radially inside the valve seat
insert outer surface, and axially at least partially aligned with
the valve seat insert second portion; and a gap located along a
surface extending from the valve seat face to the second portion
spaced from the counterbore inner surface.
19. The valve seat arrangement of claim 18, wherein when in an
un-deformed state the valve seat face is part of a curvilinear
surface extending beyond the valve seat face which meets the second
portion at an annular edge.
20. The valve seat arrangement of claim 18, wherein at least one or
more of the following structures are present: the second portion
forms an annular notch between the outer surface and the
counterbore inner surface, the second portion forms a wedge shaped
notch between the outer surface and the counterbore inner surface,
and the valve seat insert is made from an elastomeric material.
Description
FIELD
[0001] The present application relates to valve seat inserts.
BACKGROUND
[0002] Currently common engines can produce highly audible tick
noises. The frequency range of the tick noise is often in the range
of several hundred Hz to 15.0 kHz. The engine's valve train system,
which typically includes a tappet, valve, valve coil spring, valve
seat, and cam shaft(s) has been identified as a source of impact
noises including valve closing impact between the valves and valve
seats. Current valve seats have very high stiffness because of
their geometry and their way of assembly so that the high frequency
tick noises may be readily passed through to the cylinder head.
[0003] Valve seat inserts are often installed in cylinder heads to
provide a seating surface and to receive the impact from the
valves. They are typically annular shaped, and are forced or
press-fitted into counterbores at respective mouths of intake,
and/or exhaust passages. Valve seat inserts have been modified from
the typical annular configuration in effort to provide some
advantage to engine design, and/or operation. However, the
inventors herein are not aware of any modifications that have been
made to valve seat inserts for the purpose of reducing noise.
[0004] One example of valve seat insert modification is disclosed
U.S. Pat. No. 6,260,531. The disclosure provides a valve seat
insert for use in combination with a cylinder head, and includes
several notches which cooperate with a surface within a counterbore
in the cylinder head to form a plurality of passages or channels to
allow fuel to freely pass between the surface and the insert. The
channels are intended to substantially prevent fuel from becoming
trapped between the insert and the counterbore, and to prevent
formation of corrosive acids and byproducts.
[0005] The inventors herein have recognized several issues with
this approach. For example, the approach fails to recognize valve
seat inserts as a potential area within the engine to look for
noise mitigation opportunities. What is needed is an approach which
tends to isolate the impact, and consequent noise, produced by
valves closing against valve seats while still maintaining enough
strength and axial rigidity in the inserts.
[0006] Embodiments in accordance with the present disclosure may
provide a valve seat insert including a valve seat face. A
circumferential contact surface for contacting a cylinder head may
be located radially outside and at least partially axially offset
from the valve seat face. A discontinuity may be located radially
between the valve seat face and the cylinder head and at least
partially axially aligned with the valve seat face.
[0007] In this way the impact energy and vibration from the engine
valves hitting the valve seat may tend to not reach the cylinder
head, and the level of audible tick noises coming from the engine
may be reduced. Some embodiment may provide a discontinuity in the
form of a gap which may tend to make the radial stiffness of the
seat area more flexible while still withstanding impact force from
the valve. The flexibility may provide vibration isolation at
certain frequencies, and may be particularly effective at providing
high frequency isolation. The lower portion of valve seat may be
configured such that the assembled strength and axial stiffness may
provide robust strength and durability and may be used to hold the
seat in position for press-fit assembly.
[0008] It should be understood that the summary above is provided
to introduce in simplified form a selection of concepts that are
further described in the detailed description. It is not meant to
identify key or essential features of the claimed subject matter,
the scope of which is defined uniquely by the claims that follow
the detailed description. Furthermore, the claimed subject matter
is not limited to implementations that solve any disadvantages
noted above or in any part of this disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic diagram of an engine.
[0010] FIG. 2 is a detailed cross-sectional view of an example
valve arrangement that may be used with the engine illustrated in
FIG. 1 in accordance with the present disclosure.
[0011] FIG. 3 is an expanded cross-sectional view of a portion of
the valve arrangement shown in FIG. 2 in accordance with the
present disclosure.
[0012] FIG. 4 is an expanded cross-sectional view similar to FIG. 2
but illustrating another example valve arrangement in accordance
with the present disclosure.
[0013] FIG. 5 is an expanded cross-sectional view illustrating yet
another example valve arrangement in accordance with the present
disclosure.
[0014] FIG. 6 is an expanded cross-sectional view illustrating
another example valve arrangement in accordance with the present
disclosure.
[0015] FIG. 7 is an expanded cross-sectional view illustrating
another example valve arrangement in accordance with the present
disclosure.
[0016] FIG. 8 is an expanded cross-sectional view illustrating
another example valve arrangement in accordance with the present
disclosure.
[0017] FIG. 9 is an expanded cross-sectional view illustrating
another example valve arrangement in accordance with the present
disclosure.
DETAILED DESCRIPTION
[0018] In one example, the application also relates to a valve seat
insert for mitigating valve impact vibration transmission to the
cylinder head by providing a discontinuity radially between the
valve seat insert face and the cylinder head counter bore. Other
additional or alternative examples includes a valve seat including
indents on a surface edge facing a piston of an engine cylinder in
a pattern around the periphery of the seat.
[0019] FIG. 1 is a schematic diagram showing one cylinder of
multi-cylinder engine 10, which may be included in a propulsion
system of an automobile. Engine 10 may be controlled at least
partially by a control system including controller 12 and by input
from a vehicle operator 132 via an input device 130. In this
example, input device 130 includes an accelerator pedal and a pedal
position sensor 134 for generating a proportional pedal position
signal PP. Combustion chamber (i.e. cylinder) 30 of engine 10 may
include combustion chamber walls 32 with piston 36 positioned
therein. Piston 36 may be coupled to crankshaft 40 so that
reciprocating motion of the piston is translated into rotational
motion of the crankshaft. Crankshaft 40 may be coupled to at least
one drive wheel of a vehicle via an intermediate transmission
system. Further, a starter motor may be coupled to crankshaft 40
via a flywheel to enable a starting operation of engine 10.
[0020] Combustion chamber 30 may receive intake air from intake
manifold 44 via intake passage 42 and may exhaust combustion gases
via exhaust passage 48. Intake manifold 44 and exhaust passage 48
can selectively communicate with combustion chamber 30 via
respective intake valve 52 and exhaust valve 54. In some
embodiments, combustion chamber 30 may include two or more intake
valves and/or two or more exhaust valves.
[0021] Intake valve 52 may be controlled by controller 12 via
electric valve actuator (EVA) 51. Similarly, exhaust valve 54 may
be controlled by controller 12 via EVA 53. During some conditions,
controller 12 may vary the signals provided to actuators 51 and 53
to control the opening and closing of the respective intake and
exhaust valves. The position of intake valve 52 and exhaust valve
54 may be determined by valve position sensors 55 and 57,
respectively, which indicate displacement of the valve along an
axis of the actuator (see FIG. 2). As another example, cylinder 30
may include an intake valve controlled via electric valve actuation
and an exhaust valve controlled via cam actuation including cam
profile switching (CPS) and/or variable cam timing (VCT).
[0022] Fuel injector 66 is shown arranged in intake passage 44 in a
configuration that provides what is known as port injection of fuel
into the intake port upstream of combustion chamber 30. Fuel
injector 66 may inject fuel in proportion to the pulse width of
signal FPW received from controller 12 via electronic driver 68.
Fuel may be delivered to fuel injector 66 by a fuel system (not
shown) including a fuel tank, a fuel pump, and a fuel rail. In some
embodiments, combustion chamber 30 may alternatively or
additionally include a fuel injector coupled directly to combustion
chamber 30 for injecting fuel directly therein, in a manner known
as direct injection.
[0023] Intake passage 42 may include a throttle 62 having a
throttle plate 64. In this particular example, the position of
throttle plate 64 may be varied by controller 12 via a signal
provided to an electric motor or actuator included with throttle
62, a configuration that is commonly referred to as electronic
throttle control (ETC). In this manner, throttle 62 may be operated
to vary the intake air provided to combustion chamber 30 among
other engine cylinders. The position of throttle plate 64 may be
provided to controller 12 by throttle position signal TP. Intake
passage 42 may include a mass air flow sensor 120 and a manifold
air pressure sensor 122 for providing respective signals MAF and
MAP to controller 12.
[0024] Ignition system 88 can provide an ignition spark to
combustion chamber 30 via spark plug 92 in response to spark
advance signal SA from controller 12, under select operating modes.
Exhaust gas sensor 126 is shown coupled to exhaust passage 48
upstream of emission control device 70. Sensor 126 may be any
suitable sensor for providing an indication of exhaust gas air/fuel
ratio such as a linear oxygen sensor or UEGO (universal or
wide-range exhaust gas oxygen), a two-state oxygen sensor or EGO, a
HEGO (heated EGO), a NOx, HC, or CO sensor. Emission control device
70 is shown arranged along exhaust passage 48 downstream of exhaust
gas sensor 126. Device 70 may be a three way catalyst (TWC), NOx
trap, various other emission control devices, or combinations
thereof.
[0025] Controller 12 is shown in FIG. 1 as a microcomputer,
including microprocessor unit 102, input/output ports 104, an
electronic storage medium for executable programs and calibration
values shown as read only memory chip 106 in this particular
example, random access memory 108, keep alive memory 110, and a
data bus. Controller 12 may receive various signals from sensors
coupled to engine 10, in addition to those signals previously
discussed, including measurement of inducted mass air flow (MAF)
from mass air flow sensor 120; engine coolant temperature (ECT)
from temperature sensor 112 coupled to cooling sleeve 114; a
profile ignition pickup signal (PIP) from Hall effect sensor 118
(or other type) coupled to crankshaft 40; throttle position (TP)
from a throttle position sensor; and absolute manifold pressure
signal, MAP, from sensor 122. Engine speed signal, RPM, may be
generated by controller 12 from signal PIP. Manifold pressure
signal MAP from a manifold pressure sensor may be used to provide
an indication of vacuum, or pressure, in the intake manifold. In
one example, sensor 118, which is also used as an engine speed
sensor, may produce a predetermined number of equally spaced pulses
every revolution of the crankshaft thereby indicating crankshaft
position.
[0026] Storage medium read-only memory 106 can be programmed with
computer readable data representing instructions executable by
processor 102 for performing the methods or routines described
below as well as other variants that are anticipated but not
specifically listed.
[0027] As described above, FIG. 1 shows only one cylinder of a
multi-cylinder engine, and each cylinder may similarly include its
own set of intake/exhaust valves, valve position sensor(s), fuel
injector, spark plug, etc.
[0028] FIG. 2 is a detailed cross-sectional view of a valve
arrangement 198 that may be, for example, an intake valve 52, or an
exhaust valve 54 that may be used with the engine 10 illustrated in
FIG. 1, or another engine. The valve illustrated in FIG. 2 may be
referred to generally as valve 153. The valve 153 may be configured
for movement within passage 155 to open and to close the passage
155 to respectively allow a fluid to pass through the passage 155,
or to substantially prevent a fluid from passing through the
passage 155, and into, or out of, the combustion chamber 30. The
valve 153 is shown in a partially opened position. The passage 155
may be formed in, or coupled with, a cylinder head 157. The
cylinder head 157 may sit above a cylinder block (not shown). The
combustion chamber 30 may be formed at least partially in the
cylinder block which may be closed at one end with the cylinder
head 157. The passage 155 may include a counterbore 159 formed at a
mouth of the passage 155.
[0029] FIG. 3 is an expanded view of a portion of the valve
arrangement 198 shown in FIG. 2, and may be referred to in
conjunction with FIG. 2. Various embodiments may include a valve
seat insert 200 which may be positioned in the counterbore 159. The
valve seat insert 200 may include a valve seat face 202, and a
circumferential contact surface 204 for contacting the cylinder
head 157. The contact surface 204 may be located radially outside
the valve seat face 202, as illustrated with radially oriented
arrow 208, and also located at least partially axially offset from
the valve seat face 202, as illustrated with axially oriented arrow
210.
[0030] The valve seat insert 200 may also include a discontinuity
212 disposed radially between the valve seat face 202 and the
cylinder head 157 and at least partially axially aligned with the
valve seat face 202. The discontinuity 212 may make the radial
stiffness of the valve seat area more flexible, or otherwise serve
to isolate the valve seat face 202 from the cylinder head 157, when
the valve 153 impacts the valve seat face 202. The valve 153 may
contact the valve seat face 202 at a valve face 154. The
flexibility, and/or the isolation, may serve to isolate various
frequencies, for example high frequencies. In this way noise
vibration and harshness that may be otherwise caused by repeated
valve closures may be reduced, or eliminated.
[0031] In one example, the valve seat face 202 includes at least
three surfaces angled with respect to one another, one
perpendicular to the valve seat bore, and the others, one including
the discontinuity, angled obliquely thereto, and angled oppositely
with respect to one another. In one example, the surfaces of the
valve seat face 202 may be annularly shaped and form adjacent rings
with respect to one another when viewed from the direction of the
piston.
[0032] In some cases the valve seat insert 200 may have a filleted
edge 211. The filleted edge 211 may aid in inserting the valve seat
insert 200 into the counterbore 159. Some example embodiments may
not include a filleted edge 211. Some embodiments may include other
surface features.
[0033] Various embodiments may provide a valve seat insert 200 that
may include an outer surface 216 that may have a substantially
cylindrical portion 218 configured to fit within and to make
contact with the counterbore 159 within the cylinder head 157. The
cylindrical portion 218 may be, or may substantially correspond
with, the contact surface 204 described above. The outer surface
216 may also have a frusto-conical portion 220 configured to be
spaced apart from the counterbore 159. This may accordingly form a
discontinuity 212 radially between the valve seat face 202 and the
counterbore 159.
[0034] There may be a center bore 222 through the valve seat insert
200. The valve seat face 202 may be formed in the center bore 222,
and may be substantially axially aligned with the frusto-conical
portion 220. The frusto-conical portion 220 may form a wedge shaped
gap 214, or a gap 214 having a wedge shaped cross-section, between
the outer surface 216 and the counterbore 159.
[0035] The valve seat insert 200 may include a central axis 224.
The gap 214 may include a maximum radial thickness 226 of a
predetermined amount. For example the maximum radial thickness 226
may be between approximately 0.1 mm and 1.0 mm. The frusto-conical
portion 220 may include an edge 228 spaced from the substantially
cylindrical portion 218 wherein the edge 228 is nominally located
from an inner surface of the counterbore approximately 0.1 mm to
1.0 mm. In some embodiments the edge 228 may be nominally located
from an inner surface 230 of the counterbore 159 approximately 0.3
mm.
[0036] In some embodiments the valve seat insert 202 may be made
from, or include a flexible, or resilient material. In some
embodiments the valve seat insert 202 may be made from, an
elastomer. The valve seat insert 200 may be configured to deform
when the valve seat face 202 is contacted by the valve 153. In some
embodiments the gap 214 may be at least partially closed, or
substantially closed, when the valve 153 makes forcible contact
with the valve seat face 202. Further, the gap 214 may be
contiguous with a side surface of the bore, ending at a location
where the insert is in face-sharing contact with the bore.
[0037] In some embodiments, such as the one illustrated in FIG. 3,
the discontinuity 212, may be a gap 214 that may be located
adjacent to the inner surface 230 of the counterbore 159 in the
cylinder head 157 as described above. In other example embodiments,
the discontinuity 212 may be embodied differently. For example,
FIG. 4 illustrates a valve seat insert 200 in accordance with the
present disclosure wherein the discontinuity 212 may be a gap 314
spaced a distance from an inner surface 230 of the counterbore
159.
[0038] FIG. 5 illustrates another example embodiment in accordance
with the present disclosure. The discontinuity 212 may be two or
more gaps 414, for example two gaps 414 as illustrated.
[0039] FIG. 6 illustrates another example embodiment in accordance
with the present disclosure. The majority of the valve seat insert
200 may be made from a first material and the discontinuity 212 may
be made from a second material 514. In some cases the discontinuity
212 may be made from a material having a resilience, or
flexibility, which may be different from the resilience, or
flexibility of the majority of the material the valve seat insert
200 is made from. The difference in material, and/or the boundaries
between the materials may provide an inefficient energy
transmission mechanism. In this way, the energy from the valve 153
impacting the valve seat face 202 may be less effectively
transmitted to the cylinder head 157.
[0040] FIG. 7 illustrates another example embodiment in accordance
with the present disclosure. As illustrated, the discontinuity 212
may be an annular gap with a substantially rectangular
cross-section 614.
[0041] FIG. 8 illustrates another example embodiment in accordance
with the present disclosure. As illustrated, the discontinuity 212
may be, or may include, a portion of the frusto-conical portion 220
which extends beyond an outer circumferential edge 232 of the
counterbore 159. In some embodiments the valve seat insert 200 may
not include a frusto-conical portion 220, and the discontinuity 212
may be a cylindrical portion which may extend beyond an outer
circumferential edge 232 of the counterbore 159.
[0042] Referring again in particular to FIGS. 2 and 3, some
embodiments may provide a valve seat arrangement 300 which may
include a counterbore 159 in a cylinder head 157 having an inner
surface 230. A valve seat insert 200 may be fitted into the
counterbore 159 and may have an outer surface 216. The outer
surface 216 may include a first portion 218 contacting the
counterbore inner surface 230, and a second portion 220 spaced from
the counterbore inner surface 230. A valve seat face 202 may be
radially inside the valve seat insert outer surface 216, and
axially at least partially aligned with the valve seat insert
second portion 220.
[0043] Referring to some of the other figures as well, in some
embodiments the second portion 220 may form an annular notch 214,
314, 414, 614 between the outer surface 216 and the counterbore
inner surface 230. The second portion 220 may form a wedge shaped
notch between the outer surface 216 and the counterbore inner
surface 230. The valve seat insert may be made from an elastomeric
material.
[0044] FIG. 9 illustrates another example embodiment in accordance
with the present disclosure. The example illustrates a valve seat
arrangement that may be configured such that, when in an
un-deformed state, the valve seat face 202 may be part of a
curvilinear surface 902. In some cases the curvilinear surface 902
may extend beyond the valve seat face 20 and may meet the second
portion 220 at an annular edge 940.
[0045] In any of FIGS. 2-9, inclusive, a gap, discontinuity,
indent, etc., may extend continually around an entire circumference
of the insert. In other examples, it may be divided in a repeating
pattern around the annular surface facing the piston.
[0046] It should be understood that the arrangements, systems, and
methods described herein are examples, and that these specific
embodiments are not to be considered in a limiting sense, because
numerous variations are contemplated. Accordingly, the present
disclosure includes all novel and non-obvious combinations of the
various arrangements, systems, and methods disclosed herein, as
well as any and all equivalents thereof.
* * * * *