U.S. patent application number 10/947632 was filed with the patent office on 2005-04-14 for electromechanical valve actuator.
Invention is credited to Hopper, Mark L., Norton, John D., Swales, Shawn H..
Application Number | 20050076866 10/947632 |
Document ID | / |
Family ID | 34381385 |
Filed Date | 2005-04-14 |
United States Patent
Application |
20050076866 |
Kind Code |
A1 |
Hopper, Mark L. ; et
al. |
April 14, 2005 |
Electromechanical valve actuator
Abstract
A compact electromechanical valve actuator that allows the
electromechanical valves to generally be situated in closer
proximity to each other, thereby reducing overall packaging space
requirements. The electromechanical valve actuator includes a
connecting rod that is at least partially within the envelope of
the electromagnets and armature plate. The armature plate also
defines an armature envelope and the connecting rod is pivotably
coupled to the armature plate with a pivot axis within the armature
envelope.
Inventors: |
Hopper, Mark L.; (Ypsilanti,
MI) ; Norton, John D.; (Ann Arbor, MI) ;
Swales, Shawn H.; (Canton, MI) |
Correspondence
Address: |
DICKINSON WRIGHT PLLC
1901 L. STREET NW
SUITE 800
WASHINGTON
DC
20036
US
|
Family ID: |
34381385 |
Appl. No.: |
10/947632 |
Filed: |
September 22, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60510988 |
Oct 14, 2003 |
|
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|
Current U.S.
Class: |
123/90.11 |
Current CPC
Class: |
H01F 2007/086 20130101;
F01L 2009/2169 20210101; F01L 9/20 20210101; F01L 2009/2109
20210101; F01L 2009/2136 20210101 |
Class at
Publication: |
123/090.11 |
International
Class: |
F01L 009/04 |
Claims
What is claimed is:
1. An electromechanical valve actuator comprising: an armature
plate defining an armature envelope; and a connecting rod pivotably
coupled to said armature plate and having a pivot axis located
within the armature envelope.
2. The electromechanical valve actuator of claim 1 further
including a valve electromagnet and an armature electromagnet, and
wherein said armature plate is located between said electromagnets,
said valve electromagnet defining a valve electromagnet recess for
receiving at least a portion of said connecting rod.
3. The electromechanical valve actuator of claim 2 wherein said
armature plate includes an open and closed position, and wherein
said valve electromagnet defines a valve envelope, said connecting
rod including a pivot head and a shaft, said shaft being
substantially received within said valve envelope as said armature
plate moves between said open and closed positions.
4. The electromechanical valve actuator of claim 2 wherein said
connecting rod includes an armature end and said armature
electromagnet includes a pivot recess for receiving a portion of
said armature end when said armature plate is in said closed
position.
5. The electromechanical valve actuator of claim 1 wherein said
armature plate includes a reinforcing pin and wherein said
connecting rod is pivotably coupled to said reinforcing pin.
6. The electromechanical valve actuator of claim 5 wherein said
armature plate has a plate lateral extent and wherein said armature
plate further includes a hinge pin laterally displaced from said
reinforcing pin.
7. The electromechanical valve actuator of claim 6 further
including a rotary position sensor and wherein said hinge pin
extends beyond said armature envelope, said rotary position sensor
being coupled to said hinge pin.
8. The electromechanical valve actuator of claim 1 wherein said
connecting rod is formed from a substantially non-magnetic
material.
9. The electromechanical valve actuator of claim 1 wherein said
armature plate includes a plate longitudinal extent and a plate
lateral extent and wherein said longitudinal extent is at least 1.2
times greater than the lateral extent.
10. The electromechanical valve actuator of claim 1 further
including a valve and a valve electromagnet, said valve being
located substantially under said valve electromagnet.
11. The electromechanical valve actuator of claim 10 wherein said
valve includes a valve stem and said connecting rod includes an
armature end, said armature end being pivotably coupled to said
armature plate and having an arcuate movement as said valve is
moved between an open and closed position.
12. The electromechanical valve actuator of claim 11 wherein said
valve stem and said connecting rod are substantially aligned for a
portion of said arcuate movement.
13. The electromechanical valve actuator of claim 10 further
including a spring assembly substantially located under said valve
electromagnet.
14. The electromechanical valve actuator of claim 1 further
including a spring assembly and wherein said connecting rod is
configured to apply bidirectional force to said spring
assembly.
15. The electromechanical valve actuator of claim 14 wherein said
connecting rod is coupled to said spring assembly with a wedge.
16. The electromechanical valve actuator of claim 14 wherein said
connecting rod is supported for movement by said armature plate and
said spring assembly without a guide bushing.
17. The electromechanical valve actuator of claim 14 wherein said
connecting rod is coupled to said spring assembly with a pivot
pin.
18. The electromechanical valve actuator of claim 17 further
including a valve having a valve stem and wherein said connecting
rod pivots relative to said valve stem.
19. The electromechanical valve actuator of claim 1 further
including a second armature plate and a second connecting rod
wherein each of said armature plates includes a pivot pin and a
hinge pin and wherein said pivot pins and hinge pins are arranged
in a parallel relationship and wherein said connecting rod is in
closer proximity to the hinge pin of said second armature plate
than the second connecting rod is to the hinge pin of said armature
plate.
20. The electromechanical valve actuator of claim 1 wherein said
armature plate has a protruding portion, said protruding portion
including a reinforcing pin.
21. The electromechanical valve actuator of claim 20 wherein said
connecting rod is pivotably coupled to said reinforcing pin.
22. The electromechanical valve actuator of claim 20 further
including a second armature plate having a second protruding
portion, said armature plates being arranged with said protruding
portions being substantially aligned.
23. The electromechanical valve actuator of claim 20 further
including a second armature plate having a second protruding
portion and wherein said second protruding portion faces said
armature plate and said protruding portion faces said second
armature plate.
24. The electromechanical valve actuator of claim 20 further
including a second armature plate and wherein each of said armature
plates includes a pivot axis and wherein said pivot axes are
displaced so that said reinforcing pins are approximately
aligned.
25. The electromechanical valve actuator of claim 1 further
including a valve electromagnet having a core and a power coil,
said power coil being looped and defining a center portion
therebetween, and wherein said valve electromagnet defines a valve
electromagnet recess in said center portion for receiving said
connecting rod.
26. The electromechanical valve actuator of claim 1 wherein said
armature plate includes sheets of ferromagnetic material.
27. The electromechanical valve actuator of claim 1 wherein said
armature plate defines a recess, said connecting rod pivotable
within said recess, and wherein said connecting rod may be aligned
with said armature plate.
28. The electromechanical valve actuator of claim 1 further
including an armature c-block and a valve c-block, said valve
c-block securing a valve electromagnet and said armature c-block
securing an armature electromagnet, said electromagnets defining a
gap wherein said armature plate is located within said gap.
29. The electromechanical valve actuator of claim 28 wherein said
armature plate includes a hinge pin substantially secured between
said armature c-block and said valve c-block.
30. The electromechanical valve actuator of claim 29 wherein each
of said armature c-block and said valve c-block include a recess
for receiving said hinge pin.
31. The electromechanical valve actuator of claim 30 further
including a bushing located between said c-blocks and said hinge
pin.
32. The electromechanical valve actuator of claim 1 further
including a valve electromagnet and an armature electromagnet and
wherein said armature plate includes an armature surface facing
said armature electromagnet and a valve surface facing said valve
electromagnet, and wherein said valve surface and said armature
surface are not parallel.
33. The electromechanical valve actuator of claim 1 wherein said
armature plate includes a pivot end and a lever end and wherein
said armature plate tapers from said pivot end to said lever
end.
34. An electromechanical valve actuator comprising: an armature
plate including a reinforcing pin; a connecting rod pivotably
coupled to said reinforcing pin;
35. The electromechanical valve actuator of claim 34 wherein said
armature plate includes sheets of ferromagnetic material.
36. The electromechanical valve actuator of claim 34 wherein said
armature plate defines an armature envelope and said connecting rod
includes a pivot axis, said pivot axis being located within said
armature envelope.
37. The electromechanical valve actuator of claim 34 wherein said
connecting rod is formed from a nonmagnetic material.
38. The electromechanical valve actuator of claim 34 further
including a spring assembly and wherein said connecting rod is
configured to apply bidirectional force to said spring
assembly.
39. The electromechanical valve actuator of claim 34 further
including a valve electromagnet and an armature electromagnet and
wherein said armature plate includes an armature surface facing
said armature electromagnet and a valve surface facing said valve
electromagnet, and wherein said valve surface and said armature
surface are not parallel.
40. The electromechanical valve actuator of claim 34 wherein said
armature plate includes a pivot end and a lever end and wherein
said armature plate tapers from said pivot end to said lever
end.
41. An electromechanical valve actuator comprising a valve
electromagnet having an outer valve electromagnet perimeter and a
valve, said outer valve electromagnet perimeter being extended
toward said valve and wherein said valve is substantially within
said extended outer valve electromagnet perimeter.
42. The electromechanical valve actuator of claim 41 further
including an armature plate defining an armature envelope and a
connecting rod pivotably coupled to said armature plate.
43. The electromechanical valve actuator of claim 42 wherein said
connecting rod has a pivot axis located within the armature
envelope.
44. The electromechanical valve actuator of claim 42 wherein valve
electromagnet includes a valve electromagnet recess for receiving
at least a portion of said connecting rod.
45. The electromechanical valve actuator of claim 42 wherein said
armature plate further includes a reinforcing pin and wherein said
connecting rod is pivotably coupled to said reinforcing pin.
46. The electromechanical valve actuator of claim 45 wherein said
connecting rod is formed from a nonmagnetic material.
47. The electromechanical valve actuator of claim 41 wherein said
valve electromagnet includes a core and a power coil, said power
coil being looped and defining a center portion therebetween, and
wherein said valve electromagnet defines a valve electromagnet
recess in said center portion for receiving said connecting
rod.
48. The electromechanical valve actuator of claim 47 further
including an armature electromagnet having a pivot recess.
49. The electromechanical valve actuator of claim 41 further
including an armature plate having an armature surface facing said
armature electromagnet and a valve surface facing said valve
electromagnet, and wherein said valve surface and said armature
surface are not parallel.
50. The electromechanical valve actuator of claim 41 further
including an armature plate having a pivot end and a lever end and
wherein said armature plate tapers from said pivot end to said
lever end.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application No. 60/510,988, filed Oct. 14, 2003, the entire
disclosure of this application being considered part of the
disclosure of this application and hereby incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to electromechanical valve
actuators and, more particularly, to compact electromechanical
valve actuators.
[0003] As engine technology advances and manufacturers strive to
increase engine power, improve fuel economy, decrease emissions,
and provide more control over engines, manufacturers are developing
electromechanical valve actuators (also known as electromagnetic
valve actuators or EMVA) to replace camshafts for opening and
closing engine valves. Electromechanical valve actuators allow
selective opening and closing of the valves in response to various
engine conditions.
[0004] Electromechanical valve actuators generally include two
electromagnets formed from a lamination stack and an embedded power
coil. A spring loaded lever armature located between the
electromagnets is movable between the electromagnets as the power
coils are selectively energized to create a magnetic force to
attract the armature to the energized electromagnet. The surface of
the electromagnets to which the armature is attracted when the
power coil of an electromagnet is energized is generally referred
to as a pole face. The armature is operationally coupled to the
valve so that as the armature moves between pole faces in
pole-face-to-pole-face operation, the valve is opened and
closed.
[0005] One problem with traditional linear electromechanical valves
is that each valve includes a relatively large set of
electromagnets for opening and closing the valves, making it
difficult to position all the electromechanical valve actuators on
engines, especially on engines that have four or more valves per
cylinder. Linear electromechanical valve actuators also generally
draw a substantial amount of power from the alternator and with
some engines having four or more valves per cylinder, the power
drain on the alternator for the four or more electromechanical
valve actuators is substantial. It is desirable to minimize power
consumption of the electromechanical valve actuators in modern
vehicles which have many competing power demands. In view of the
drawbacks associated with linear electromechanical valve actuators,
many manufacturers have recently been turning to lever
electromechanical valve actuators, which due to their mechanical
properties have substantial power savings. One problem with lever
electromechanical valve actuators is still the package size
required on the cylinder head. The package size is increased
because the valve on lever electromechanical valve actuators is
located well outside the envelope of the electromagnets, thereby
increasing the package space required for each electromechanical
valve actuator. An example of a prior art arrangement of lever
electromechanical valve actuators 10' over the cylinder 16 and
location of the associated armature plate 32' and valve 20 may be
seen in FIG. 10. As shown in FIG. 10, electromechanical valve
actuators on an engine having four valves 20 per cylinder 16
require significantly more space than camshafts, thereby presenting
packaging concerns in engine compartments where space is limited.
Therefore, there is a need for a compact lever electromechanical
valve actuator with low power consumption.
SUMMARY OF THE INVENTION
[0006] The present invention relates to electromechanical valve
actuators and, more particularly, to compact lever
electromechanical valve actuators.
[0007] Compact electromechanical valve actuators allow the
individual electromechanical valve actuators or pairs of
electromechanical valve actuators to be situated in close
proximity. The compact electromechanical valve actuator includes an
armature plate having an armature envelope and a connecting rod
pivotably coupled to the armature plate within the armature
envelope. The electromechanical valve actuator further includes a
spring assembly to which the armature plate applies a
bi-directional force through the connecting rod to open and close
the valve. The connecting rod is located at least partially within
the envelope of the electromagnets and the envelope of the armature
plate to reduce the amount of space required on the engine. The
location of the connecting rod allows the lever electromechanical
valve actuators to be located at least partially over the
valve.
[0008] Further scope of applicability of the present invention will
become apparent from the following detailed description, claims,
and drawings. However, it should be understood that the detailed
description and specific examples, while indicating preferred
embodiments of the invention, are given by way of illustration
only, since various changes and modifications within the spirit and
scope of the invention will become apparent to those skilled in the
art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention will become more fully understood from
the detailed description given here below, the appended claims, and
the accompanying drawings in which:
[0010] FIG. 1 is a sectional view of the electromechanical valve
actuator;
[0011] FIG. 2 is an enlarged sectional view of the armature
plate;
[0012] FIG. 3 is a top sectional view;
[0013] FIG. 4 is a perspective view of the armature plate and
connecting rod with the electromagnets shown in phantom lines;
[0014] FIG. 5 is a perspective view of an alternative armature
plate and connecting rod with the electromagnets shown in phantom
lines;
[0015] FIG. 6 is a top plan view of a second alternative armature
plate showing the reinforcing pins with hidden lines;
[0016] FIG. 7 is a top plan view of the valve electromagnets for
use in connection with the second alternative armature plate shown
in FIG. 6;
[0017] FIG. 8 is an enlarged sectional view of the connecting rod
coupled to the armature spring assembly with a wedge fastener;
[0018] FIG. 9 is an enlarged sectional view of an alternative
embodiment with the connecting rod being coupled to the armature
spring assembly with a pivot connection;
[0019] FIG. 10 is a prior art top plan view of the placement of
lever electromechanical valve actuators on a cylinder head;
[0020] FIG. 11 is a top view of the armature plate of a second
alternative embodiment;
[0021] FIG. 12 is a top view of the valve electromagnets of the
second alternative embodiment;
[0022] FIG. 13 is a perspective view of the electromechanical valve
actuator of the second alternative embodiment with the
electromagnets shown in phantom lines;
[0023] FIG. 14 is a side sectional view of a third alternative
embodiment; and
[0024] FIG. 15 is a top sectional view of the third alternative
embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] A lever electromechanical valve actuator 10, typically
mounted on an internal combustion engine 12 to open and close a
valve 20 (e.g., the intake or exhaust valves), is illustrated in
FIG. 1. As described in greater detail below, the lever
electromechanical valve actuator 10 of the present invention
provides greater freedom in placement on the engine 12 a more
compact arrangement, and allows the lever electromechanical valve
actuator 10 to be situated at least partially over the valve 20.
The electromechanical valve actuator 10 generally includes an
armature assembly 30 having an armature plate 32, an electromagnet
assembly 70 having electromagnets 72, 74, a connecting rod 90 and a
spring assembly 60. The armature plate 32 is alternatively
attracted to the electromagnets 72, 74, thereby applying a
bi-directional force to the spring assembly 60 through the
connecting rod 90 to open and close the valve 20.
[0026] The valve 20 is similar to traditional valves and generally
includes a valve head 22 with a valve stem 24 extending therefrom.
The valve 20 has an open and a closed position wherein in the
closed position the valve head 22 seals a valve port 14 to the
corresponding cylinder 16. The spring assembly 60 includes springs
62 and 64 sized to bias the armature plate 32 into an intermediate
position, shown in FIG. 2, while the electromagnets 74, 74 are not
energized.
[0027] The electromagnet assembly 70 controls the movement of the
armature assembly 30, and thereby the movement of the valve 20. The
electromagnets 72, 74 include cores 76 which may be formed from
laminated plates (not shown) to improve the magnetic efficiency of
the electromagnets 72, 74. A coil 78 is situated within each core
76 and is selectively energized to attract the armature plate 32 to
the electromagnets 72, 74. C-blocks 8, 9 generally secure the
electromagnets 72, 74 in position and are separated by a spacer
block 6 to form the gap 15 between the electromagnets 72, 74 in
which the armature plate 32 is located. The c-blocks 8, 9 may be
formed without the need for a spacer, as shown in FIGS. 14 and 15.
Also, the valve c-block 8, illustrated in FIG. 15, may support a
bushing 43 to help reduce friction and increase longevity of the
electromechanical valve actuator 10. The armature c-block 9 is
typically a mirror image of the valve c-block 8, although other
sizes, shapes, and configurations may be used. Of course, the
spacer block 6 or a two part spacer block (not shown) may support a
guide bushing to reduce friction. The c-blocks 8, 9 may be
elongated and configured to hold a pair of electromechanical valve
actuators 10 in line with each other (not shown). The c-blocks 8, 9
may also be formed as a double c-block, having an "E-configuration"
(not shown) to hold a pair of adjacent electromechanical valve
actuators 10. Of course, the c-blocks 8, 9 may also be configured
to hold any number of electromechanical valve actuators 10, such as
holding as many electromechanical valves actuators as there are
valves 20 per cylinder 16. The c-blocks 8, 9 and spacer block 6 may
be directly coupled to the engine 12 as illustrated in FIG. 1 or a
housing (not shown) may secure them. In the illustrated embodiment,
the housing generally fits over the electromechanical valve
actuators 10 similar to a valve cover to protect the
electromechanical valve actuators 10 from dirt and debris while
retaining lubrication. The housing may cover individual
electromechanical valve actuators 10, multiple electromechanical
valve actuators 10, such as a pair or all electromechanical valve
actuators over a particular cylinder 16 or all electromechanical
valve actuators on a bank of cylinders. A base plate 17 may be
installed on the engine 12 as shown in FIGS. 1 and 2.
[0028] The armature assembly 30 includes the armature plate 32 and
the connecting rod 90. The armature plate 32 pivots about an
armature pivot axis 44, near a pivot end 49 of the armature plate
32, to open and close the valve 20. The connecting rod 90 is
coupled to the armature plate 32 near a lever end 48, opposite the
armature pivot axis 44, and in a manner that transmits forces from
the armature plate 32 to the connecting rod 90 in both the opening
and closing directions. The armature plate 32 further includes a
hinge pin 42 and at least one reinforcing pin 38. While the
armature plate 32 may pivot relative to the hinge pin 42 it is
generally desirable for the hinge pin 42 to be secured to the
armature plate 32 so that the hinge pin 42 pivots with the plate 32
about the armature pivot axis 44 defined by center of the hinge pin
42 as illustrated in FIGS. 4, 5, and 15. The pivoting of the hinge
pin 42 relative to the c-blocks 8, 9 and with the armature plate
32, as the armature plate 32 moves the valve 20 between the open
and closed positions, has various benefits. First, the hinge pin 42
provides an economical and easy to assemble pivot without precise
welding or machining of the armature plate to the hinge pin 42 or
to a holder for the hinge pin 42. Second, the hinge rod aligns and
secures the laminated plates 34 without precise machining of the
armature plate and without welding the individual plates 34
together. Third, the hinge pin 42 may extend beyond the envelope of
the armature plate 32 to allow attachment of a rotary position
sensor 56, as illustrated in FIG. 3, for precise yet economical
sensing of the rotational location of the armature plate 32.
Fourth, by limiting the length of the hinge pin 42 upon which
relative rotation occurs, friction losses from rotation can be
minimized. Fifth, the hinge pin 42 also acts as a stiffening member
to the armature plate 32. In the illustrated embodiment, the hinge
pin 42 is secured to the armature plate 32 with an interference
fit, but other techniques, such as coining the ends of the hinge
pin 42 or welding the hinge pin 42 to the armature plate 32 may be
used.
[0029] The armature plate 32 also includes a reinforcing pin 38
disposed laterally from the hinge pin 42. As illustrated in FIGS.
1-5, the reinforcing pin 38 may act as a pivot pin 40. More
specifically, the connecting rod 90 may be pivotably coupled to the
reinforcing pin 38 making that reinforcing pin 38 the pivot pin 40.
The pivot pin 40 stiffens the armature plate 32 to prevent flex of
the armature plate 32 as well as distributes forces from the
connecting rod 90 longitudinally across the laminated plates 34.
More specifically, the reinforcing pin 38 prevents shearing of the
laminated plates 34 as the armature plate 32 applies force to the
connecting rod 90. Use of a pivot pin 40 that also acts as a
reinforcing pin 38 helps improve magnetic efficiency of the
armature plate 32 by minimizing potential disruptors to the
magnetic flux through the armature plate 32 near the lever end 48.
The lever end 48 has the highest magnetic attraction and becomes
saturated with magnetic flux, under some conditions. In the
illustrated embodiment, the reinforcing pin 38 is secured to the
armature plate 32 with an interference fit by being forcibly
inserted into aligned holes in the laminated plates 34, but may be
secured to the armature plate 32 by any known method, including
coining the ends of the reinforcing pin 38 or welding the
reinforcing pin 38 in place. A stiffer armature plate 32 minimizes
flexing as the armature plate pivots and thereby provides more
efficient operation. The additional stiffening of the armature
plate 32 also allows placement of the connecting rod 90 anywhere
along the lever end 48 of the armature plate 32, as illustrated in
FIGS. 4 and 5.
[0030] To further improve magnetic efficiency and package size, the
longitudinal extent 52 of the armature plate 32 may be 1.2 times
greater than the lateral extent 50 of the armature plate 32, as
illustrated in FIG. 11. The armature plate 32 may also include a
protruding portion 54 (FIG. 6) designed to improve the mechanical
advantages of the lever electromechanical valve actuator 10. The
electromagnets 72, 74 may also include a protruding portion 55, as
illustrated on the valve electromagnets 74 in FIG. 7. To further
improve magnetic efficiency, packaging and durability, as well as
minimize the moving mass of the armature plate 32, the armature
plate 32 may be formed with surfaces that are not parallel, as
illustrated in FIG. 14. In FIG. 14, the armature plate 32 tapers
from the pivot end 49 to the lever end 48.
[0031] To provide a more compact electromechanical valve actuator
10, the armature plate 32 includes a recess 36. The recess 36
receives the connecting rod 90 so that at least a portion of the
connecting rod 90 is located within the envelope of the armature
plate 32. As used throughout the specification and in the claims,
the term "envelope of the armature plate" or "armature plate
envelope" generally refers to the outer perimeter of the armature
plate 32 without any recesses, such as the illustrated recess 36.
Therefore, any point within the outer perimeter of the armature
plate 32 irrespective of the recess 36 is located within the
envelope of the armature plate 32 The envelope of the armature
plate 32 generally does not include any welded protrusions that do
not function to magnetically attract the armature plate 32 to the
electromagnets 72, 74. The recess 36 is designed to provide the
space necessary for the connecting rod 90 to pivot freely about
pivot pin 40. A compact electromechanical valve actuator 10
facilitates packaging flexibility, such as allowing the
electromechanical valve actuators 10 to be placed in close
proximity to one another on the engine 12. As shown in FIGS. 11-14,
the recess 36 may be located anywhere within the envelope of the
armature so long as the connecting rod 90 may drive the valve 20
without interfering with the power coils 78. By locating the
connecting rod 90 at least partially within the envelope of the
armature plate, the electromechanical valve actuator 10 may be
located at least partially over the valve 20 as illustrated in FIG.
3. Even when the connecting rod 90 is pivotably coupled to the
armature plate 32 closer to the lateral center, as illustrated in
FIG. 13, the recess 36 may still extend from the lever end 48 to
beyond the pivot pin 40. The recess 36 extending to the lever end
48 facilitates manufacturing and shipping of the armature assembly
30 by allowing the connecting rod 90, specifically the shaft 96 to
be rotated and to be generally aligned with the armature plate 32
for shipping. Aligning the connecting rod 90 with the armature
plate 32 during shipping shrinks the size required for each
armature assembly 30, and minimizes potential damage to the
armature assembly during shipment.
[0032] The connecting rod 90 may be made in almost any size and
shape so long as it transfers bi-directional force from the
armature assembly 30 to the spring assembly 60. The connecting rod
90 is illustrated in FIGS. 1 and 8 as having a pivot pin passage on
an armature end 92 and a wedge 100 secured to the valve end 94 with
a shaft 96 therebetween. The wedge 100 is similar to wedges used in
valve spring retainers for camshafts for ease of manufacture and
low cost. The connecting rod 90 pivots about the pivot pin 40 and
the design of the spring assembly 60 including the wedge 100 allows
some pivoting relative to the valve stem 24 during the arcuate
movement of the lever end 48 of the armature plate 32. In FIG. 8,
the connecting rod 90 extends toward the valve 20 and during
opening of the valve 20, the connecting rod 90 is axially displaced
to contact the valve stem 24. The wedge 100 is mechanically trapped
between the connecting rod 90 and the armature spring retainer 68
by the force applied by the armature spring 64. More specifically,
the wedge 100 includes two keepers which are assembled into a
groove (not shown) on the connecting rod 90 and the force applied
by the armature spring 64 to the armature spring retainer 68 keeps
the wedge 100 secured within the groove on the connecting rod 90,
so that the connecting rod 90 may apply bi-directional force to the
spring assembly 60. Alternatively, the wedge 100 may be press fit,
welded, or otherwise secured on the connecting rod 90. The slightly
rounded ends of the valve stem 24 and connecting rod 90 allow a
limited range of pivotal movement relative to each other as the
armature plate 32 pivots. The valve spring 62 is also retained by a
valve spring retainer 66.
[0033] The connecting rod 90 may include other variations where the
connecting rod extends toward the valve stem 24 and pushes directly
on the armature spring retainer 68, valve spring retainer 66, or
valve stem 24 to provide bi-directional force to the spring
assembly 60 without using the wedge. In an alternative embodiment,
shown in FIG. 9, the connecting rod 90 may be coupled to the
armature spring retainer 68 with a retainer pin 69 in place of the
wedge 100 allowing the connecting rod 90 to freely pivot at both
ends 92 and 94.
[0034] The spring assembly 60 is located between the electromagnet
assembly 70 and the cylinder 16 as illustrated in FIG. 1. The
spring assembly 60 includes the valve spring 62 and the armature
spring 64, each of which are, as illustrated, preferably located
below the armature plate 32 for a more compact valve actuator 10.
The valve spring 62 provides the closing force to the valve 20 and
is retained on the valve stem 24 by a valve spring retainer 66. The
armature spring 64 assists the armature assembly 30 in opening of
the valve 20 by providing an opening force. The armature spring 64
is retained on the connecting rod 90 by an armature spring retainer
68. The placement of the springs 62 and 64 below the armature plate
32 provides opposed spring forces to facilitate the desired
movement of the armature plate 32 while improving the overall
compactness of the actuator relative to prior art designs. The
combination of the opposing springs 62, 64 located below the
armature plate 32 also prevents the opposing spring forces from
being carried by the connecting rod 90, any bushings coupled to the
connecting rod to facilitate pivoting, and the armature plate
32.
[0035] The valve electromagnet 72 may include a valve electromagnet
recess 82 as illustrated in FIGS. 1-5, 7, 11, 13, and 14, and the
armature electromagnet 74 may include a pivot recess 84 as
illustrated in FIG. 1. The valve electromagnet recess 82 and the
pivot recess 84 are in alignment with the recess 36 in the armature
plate 32 to receive the connecting rod 90 at least partially within
the envelope of the electromagnets 72, 74. As used throughout the
specification and in the claims the terms "envelope of the armature
magnet," "envelope of the valve electromagnet," or "envelope of the
electromagnets" generally refers to the outer perimeter of the
electromagnet 72, 74 without the recesses 82 and 84. With the
connecting rod 90 movable at least partially within the envelope of
the electromagnets 72, 74, the electromechanical valve actuators 10
may be located in closer proximity to each other and arranged on
the engine 12 in a more compact fashion. As illustrated in FIG. 1,
the valve 20 may be located at least partially under the
electromagnets 72, 74.
[0036] As illustrated in FIGS. 14 and 15, the hinge pin 42 may be
substantially larger than the reinforcing pins 38, to carry the
applied load as the valve 20 is cycled between the open and closed
positions. The hinge pin 42 may rotate in bushings 43 to reduce
friction. Although not illustrated, the connecting rod 90 may also
be pivotably coupled to the pivot pin 40 with bushings to reduce
friction. As further illustrated in FIG. 15, the location of the
reinforcing pins 38 may vary if any reinforcing pins 38 are
included that are not pivot pins 40.
[0037] The compact electromechanical valve actuators 10 described
above provide space savings and facilitate the use of more compact
actuator placement patterns relative to each cylinder. The
connecting rod 90 being coupled at both ends 92, 94 also allows the
elimination of guide bushings typically used to traditionally guide
an armature stem. Elimination of the guide bushing reduces friction
and assembly cost. Reduction in friction is desirable because it
allows operation of the electromechanical valve actuator 10 with
less power consumption.
[0038] The present invention provides a lever electromechanical
valve actuator 10 with compact packaging over the engine. Compact
packaging is provided for by using a connecting rod 90 that is at
least partially located within the envelope of the electromagnets
72, 74 and armature plate 32. The compact packaging is further
facilitated by locating the spring assembly 60 between the
electromechanical valve actuator 10 and the cylinder 16. The
armature plate 32 provides a bi-directional force through the
connecting rod 90 to move the valve between an open and closed
position. The compact actuator design allows the valve 20 to
substantially be located under the armature plate 32 or valve
electromagnet 72 as shown in FIG. 3.
[0039] The foregoing discussion discloses and describes an
exemplary embodiment of the present invention. One skilled in the
art will readily recognize from such discussion, and from the
accompanying drawings and claims that various changes,
modifications and variations can be made therein without departing
from the true spirit and fair scope of the invention as defined by
the following claims.
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