U.S. patent application number 15/989822 was filed with the patent office on 2019-11-28 for air shutoff valve.
This patent application is currently assigned to Caterpillar Inc.. The applicant listed for this patent is Caterpillar Inc.. Invention is credited to Eric W. Ferguson, Rodney A. Lawrence, Yegor Litvinov, Bradley J. Shaffer, Joseph John Stabnik, Brandyn A. Stack.
Application Number | 20190360437 15/989822 |
Document ID | / |
Family ID | 68466377 |
Filed Date | 2019-11-28 |
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United States Patent
Application |
20190360437 |
Kind Code |
A1 |
Lawrence; Rodney A. ; et
al. |
November 28, 2019 |
Air Shutoff Valve
Abstract
An air shutoff valve for use on an internal combustion engine
includes a gate that is moveable between armed and triggered
positions by springs when a release pin is retracted and allows a
spring loaded retention pin to retract and release the gate, which
is also spring loaded, to drop. The release pin is operated by an
actuator.
Inventors: |
Lawrence; Rodney A.;
(Frankfort, IN) ; Shaffer; Bradley J.; (Romney,
IN) ; Stack; Brandyn A.; (Lafayette, IN) ;
Stabnik; Joseph John; (Rensselaer, IN) ; Ferguson;
Eric W.; (Cottage Grove, MN) ; Litvinov; Yegor;
(Shakopee, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Caterpillar Inc. |
Deerfield |
IL |
US |
|
|
Assignee: |
Caterpillar Inc.
Deerfield
IL
|
Family ID: |
68466377 |
Appl. No.: |
15/989822 |
Filed: |
May 25, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16K 35/025 20130101;
F16K 31/52416 20130101; F02M 35/10255 20130101; F16K 3/0254
20130101; F16K 3/0281 20130101; F16K 31/465 20130101; F16K 31/56
20130101 |
International
Class: |
F02M 35/10 20060101
F02M035/10; F16K 3/02 20060101 F16K003/02 |
Claims
1. An air shutoff valve for use on an internal combustion engine,
comprising: a body having an inlet portion forming an inlet
opening, an outlet portion forming an outlet opening, a gate
portion and an actuator portion; the body forming an air passage
that fluidly connects the inlet opening and the outlet opening; a
gate slidably disposed in the gate portion of the body, the gate
being selectively moveable between an armed position and a
triggered position, in which triggered position the gate is
disposed in the air passage and fluidly blocks the outlet opening
from the inlet opening; a lift rod connected to the gate, the lift
rod including a transverse opening; a retention pin slidably
disposed in the actuator portion of the body, the retention pin
having a tip extending through the transverse opening in the lift
rod when the gate is in the armed position; a release pin disposed
in a release opening formed in the retention pin when the gate is
in the armed position, the release pin preventing sliding motion of
the retention pin relative to the body when the release pin is in
an extended position; an actuator connected to the release pin and
operating to move the release pin from the extended position to a
retracted position, in which the release pin is clear of the
retention pin; at least one spring disposed between the body and
the retention pin, the at least one spring disposed to urge the
retention pin in a direction away from the lift rod; and at least
one lift spring disposed between the body and the gate, the at
least one lift spring disposed to urge the gate towards the
triggered position.
2. The air shutoff valve of claim 1, further comprising a linkage
mechanism that operates to mechanically associate a position of the
gate with a position of the retention pin relative to the body.
3. The air shutoff valve of claim 2, wherein the linkage mechanism
includes a driver, and wherein rotation of the driver is configured
to move the gate from the triggered position to the armed position
and also to move the retention pin towards the transverse opening
in the lift rod to lock the gate in the armed position.
4. The air shutoff valve of claim 3, wherein the linkage mechanism
includes a sprocket rotatably mounted on the body and connected to
the driver such that rotation of the driver causes a corresponding
rotation of the sprocket.
5. The air shutoff valve of claim 4, wherein the linkage mechanism
further includes a chain, which is meshably engaged with the
sprocket, the chain having one end connected to the sprocket and
another end connected to an end of the lift rod such that rotation
of the driver and sprocket in a winding direction causes the chain
to pull onto the lift rod and move the gate from the triggered
position towards the armed position.
6. The air shutoff valve of claim 1, wherein the body further
includes at least one bore disposed in the gate portion and
extending parallel to a travel direction of the gate, and wherein
the at least one bore includes the at least one lift spring.
7. The air shutoff valve of claim 6, wherein the gate includes an
arm that extends into the at least one bore, wherein a plug is
slidably disposed within the at least one bore and contacts the
arm, and wherein the at least one lift spring is compressively
disposed between an end of the at least one bore and the plug.
8. The air shutoff valve of claim 4, further comprising a pawl
connected to the sprocket and extending radially outwardly
therefrom, the pawl being arranged to contact a pocket formed in
the retention pin and to push the retention pin towards the
transverse opening as the sprocket rotates in the winding
direction.
9. The air shutoff valve of claim 1, further comprising an
expansion chamber formed in the body and surrounding at least a
portion of the gate when the gate is disposed in the armed
position.
10. The air shutoff valve of claim 1, wherein the transverse
opening is a slot extending through the lift rod.
11. An air shutoff valve for an internal combustion engine
comprising a gate valve element slidably disposed within a body of
the valve and operating to selectively fluid connect or block an
air passage, the gate valve element moving along a guillotine axis
between a retracted position, in which the air passage is clear,
and an extended position, in which the air passage is blocked, the
air shutoff valve further comprising: a linear actuator operating
between a default, extended actuator position and an active,
retracted actuator position; a release pin disposed to move with
the linear actuator between the extended and retracted actuator
positions; a retention pin slidably disposed in the body of the
valve, the retention pin having an opening that accepts therein a
portion of the release pin; at least one spring disposed between
the body of the valve and the retention pin, the at least one
spring urging the retention pin in one direction; a lift rod
connected to the gate valve element, the lift rod having an
elongate slot that accepts therein a tip of the retention pin; and
at least one lift spring disposed between the body of the valve and
the gate valve element, the at least one lift spring urging the
gate valve element towards the extended position.
12. The air shutoff valve of claim 11, wherein in an armed state:
the linear actuator is in the extended position; the release pin is
disposed in the opening of the retention pin, thus preventing
motion of the retention pin relative to the body of the valve and
the lift rod; the at least one spring is compressed; the tip of the
retention pin is disposed within the elongate slot in the lift rod,
thus preventing the lift rod from moving relative to the body of
the valve; and the at least one lift spring is compressed; and the
gate valve element is disposed in the retracted position.
13. The air shutoff valve of claim 12, wherein during a trigger
event: the linear actuator is activated to move to the retracted
position at least temporarily; the release pin moves to be clear of
the opening of the retention pin, thus allowing motion of the
retention pin relative to the body of the valve and the lift rod,
at least temporarily; the at least one spring is extended to push
the retention pin away from the lift rod; the tip of the retention
pin clears the elongate slot in the lift rod, thus allowing the
lift rod to move relative to the body of the valve; and the at
least one lift spring is extended to push the gate valve element
from the retracted position to the extended position.
14. The air shutoff valve of claim 13, wherein in a triggered
state: the linear actuator is free to move to the extended
position; the release pin is free to move into the opening of the
retention pin when the opening becomes aligned with the release
pin; and the gate valve element is disposed in the extended
position.
15. The air shutoff valve of claim 14, further comprising a
sprocket rotatably disposed on the body, and a chain meshed with
the sprocket and connected between the sprocket and an end of the
lift rod, the sprocket further including a driver rotatably
associated therewith and a pawl connected with the sprocket and
extending radially outwardly therefrom, and wherein when
transitioning from the triggered state to the armed state: a user
rotates the driver, thus rotating the sprocket in a winding
direction; the chain is taken up by the sprocket and pulls the lift
rod and the gate valve element towards the retracted position; the
pawl rotates and engages a notch in the retention pin, thus pushing
the retention pin towards the lift rod; the opening of the
retention pin aligns with the release pin, and the release pin
engages the opening; the tip of the retention pin enters the
elongate slot; the at least one spring is compressed; and the at
least one lift spring is compressed.
16. An air shutoff valve for an internal combustion engine,
comprising: a body forming an air passage that fluidly connects an
inlet opening with an outlet opening; a gate slidably disposed in
the body and being selectively moveable along a gate axis between
an armed position and a triggered position, in which the air
passage is fluidly blocked; a lift rod connected to the gate and
including a transverse opening; a retention pin slidably disposed
in the body along a retention axis and having a tip extending
through the transverse opening in the lift rod when the gate is in
the armed position; a release pin disposed in a release opening
formed in the retention pin when the gate is in the armed position,
the release pin preventing sliding motion of the retention pin
relative to the body when the release pin is in an extended
position; an actuator connected to the release pin and operating to
move the release pin along an actuator axis from the extended
position to a retracted position, in which the release pin is clear
of the retention pin; at least one spring disposed between the body
and the retention pin, the at least one spring disposed to urge the
retention pin in a direction away from the lift rod; and at least
one lift spring disposed between the body and the gate, the at
least one lift spring disposed to urge the gate towards the
triggered position; wherein the gate axis and the actuator axis are
parallel; and wherein the actuator axis and the retention axis are
perpendicular.
17. The air shutoff valve of claim 16, wherein the gate, actuator
and retention axes are coplanar.
18. The air shutoff valve of claim 16, further comprising a linkage
mechanism that operates to mechanically associate a position of the
gate with a position of the retention pin relative to the body, the
linkage mechanism comprising: a driver, wherein rotation of the
driver is configured to move the gate from the triggered position
to the armed position and also to move the retention pin towards
the transverse opening in the lift rod to lock the gate in the
armed position; a sprocket rotatably mounted on the body and
connected to the driver such that rotation of the driver causes a
corresponding rotation of the sprocket; and a chain being meshably
engaged with the sprocket, the chain having one end connected to
the sprocket and another end connected to an end of the lift rod
such that rotation of the driver and sprocket in a winding
direction causes the chain to pull onto the lift rod and move the
gate from the triggered position towards the armed position;
wherein an axis of rotation about which the sprocket rotates is
perpendicular to a plane defined by the gate axis and the actuator
axis.
19. The air shutoff valve of claim 18, further comprising a pawl
connected to the sprocket and extending radially outwardly
therefrom, the pawl being arranged to contact a pocket formed in
the retention pin and to push the retention pin towards the
transverse opening as the sprocket rotates in the winding
direction.
20. The air shutoff valve of claim 16, further comprising an
expansion chamber formed in the body and surrounding at least a
portion of the gate when the gate is disposed in the armed
position.
Description
TECHNICAL FIELD
[0001] This patent disclosure relates generally to internal
combustion engines and, more particularly, to air shutoff valves
used on internal combustion engines.
BACKGROUND
[0002] Certain types of internal combustion engines, including
engines that include reciprocating pistons, are typically operated
by controlling either the air or fuel provided into the cylinders
of the engine. For example, spark ignition engines such as gas or
gasoline engines control engine speed by metering an amount of air
that is provided to the engine, measuring the amount of air, and
providing a controlled amount of fuel to achieve a desired air/fuel
ratio. Similarly, compression combustion engines such as diesel or
oil engines control engine speed by metering the amount of fuel
that is provided to the engine's cylinders. In any event, internal
combustion engines require at least air and fuel to form a
combustible air/fuel mixture in the engine's cylinders to operate.
If provision of fuel or air is discontinued, then operation of the
engine would be discontinued or prevented from initiating.
[0003] In certain conditions, for example, in the presence of a
failure, it is desirable to inhibit engine operation for reasons of
safety. In yet other conditions, a failure in an engine component
may result in an uncontrolled flow of fuel (or air) into the
engine, which can create a condition of uncontrolled engine
operation. One previously proposed solution at disabling engine
operation during either a safety lockout or in the presence of an
engine component failure is to introduce an air shutoff valve at a
point in the engine's air intake system, which operates to shut off
an airflow into the engine.
[0004] One example of an air shutoff valve that has been proposed
in the past can be found in U.S. Pat. No. 4,546,954, which was
granted on Oct. 15, 1985. This reference describes an air shutoff
valve having a paddle-shaped valve element that includes a circular
gate and an actuation arm. The actuation arm pivots at one end
under a force of an actuator (see, e.g., FIG. 3a) to swing the gate
valve into and out from an air passage opening.
[0005] One disadvantage of existing air shutoff valves such as the
valve described in the '954 patent mentioned above, is that a large
actuator force is required to move the valve element when the valve
is required to be used. Moreover, placement of the valve on the
engine's intake system, which is usually high on the engine,
subjects the valve to vibration and wear of internal components
such as linkages and the like.
SUMMARY
[0006] The disclosure describes, in one aspect, an air shutoff
valve for use on an internal combustion engine. The air shutoff
valve includes a body having an inlet portion forming an inlet
opening, an outlet portion forming an outlet opening, a gate
portion and an actuator portion. The body forms an air passage that
fluidly connects the inlet opening and the outlet opening. The gate
is slidably disposed in the gate portion of the body and is
selectively moveable between an armed position and a triggered
position, in which triggered position the gate is disposed in the
air passage and fluidly blocks the outlet opening from the inlet
opening. A lift rod is connected to the gate and includes a
transverse opening. A retention pin is slidably disposed in the
actuator portion of the body and has a tip extending through the
transverse opening in the lift rod when the gate is in the armed
position. A release pin is disposed in a release opening formed in
the retention pin when the gate is in the armed position. The
release pin prevents sliding motion of the retention pin relative
to the body when the release pin is in an extended position. An
actuator is connected to the release pin and operates to move the
release pin from the extended position to a retracted position, in
which the release pin is clear of the retention pin. At least one
resilient element is disposed between the body and the retention
pin. The at least one spring is disposed to urge the retention pin
in a direction away from the lift rod. At least one lift spring is
disposed between the body and the gate. The at least one lift
spring is disposed to urge the gate towards the triggered
position.
[0007] In another aspect, the disclosure describes an air shutoff
valve for an internal combustion engine, which includes a gate
valve element slidably disposed within a body of the valve and
operating to selectively fluid connect or block an air passage, the
gate valve element moving along a guillotine axis between a
retracted position, in which the air passage is clear, and an
extended position, in which the air passage is blocked. The air
shutoff valve further includes a linear actuator operating between
a default, extended actuator position and an active, retracted
actuator position, a release pin disposed to move with the linear
actuator between the extended and retracted actuator positions, a
retention pin slidably disposed in the body of the valve, the
retention pin having an opening that accepts therein a portion of
the release pin, at least one resilient element disposed between
the body of the valve and the retention pin, the at least one
spring urging the retention pin in one direction, a lift rod
connected to the gate valve element, the lift rod having an
elongate opening that accepts therein a tip of the retention pin,
and at least one lift spring disposed between the body of the valve
and the gate valve element, the at least one lift spring urging the
gate valve element towards the extended position.
[0008] In yet another aspect, the disclosure describes an air
shutoff valve for an internal combustion engine, which includes a
body forming an air passage that fluidly connects and inlet opening
with an outlet opening, a gate slidably disposed in the body and
being selectively moveable along a gate axis between an armed
position and a triggered position, in which the air passage is
fluidly blocked, a lift rod connected to the gate and including a
transverse opening, a retention pin slidably disposed in the body
along a retention axis and having a tip extending through the
transverse opening in the lift rod when the gate is in the armed
position, a release pin disposed in a release opening formed in the
retention pin when the gate is in the armed position, the release
pin preventing sliding motion of the retention pin relative to the
body when the release pin is in an extended position, an actuator
connected to the release pin and operating to move the release pin
along an actuator axis from the extended position to a retracted
position, in which the release pin is clear of the retention pin,
at least one resilient element disposed between the body and the
retention pin, the at least one spring disposed to urge the
retention pin in a direction away from the lift rod, and at least
one lift spring disposed between the body and the gate, the at
least one lift spring disposed to urge the gate towards the
triggered position. In one embodiment, the gate axis and the
actuator axis are parallel, and the actuator axis and the retention
axis are perpendicular.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an outline view of an air shutoff valve for use
with an internal combustion engine in accordance with the
disclosure.
[0010] FIG. 2 is a cross section through the valve shown in FIG.
1.
[0011] FIG. 3 is an enlarged detail of the cross section of FIG.
2.
[0012] FIG. 4 is a cross section through a linkage portion of the
valve of FIG. 1.
[0013] FIG. 5 is an enlarged detail of the cross section of FIG.
2.
[0014] FIG. 6 is an outline view of a gate element.
[0015] FIG. 7 is an enlarged cross section through the gate element
of FIG. 6.
[0016] FIGS. 8 and 9 are cross sections from different perspectives
of a gate portion of the valve shown in FIG. 1.
[0017] FIG. 10 is an outline view of a linkage mechanism of the
valve of FIG. 1, shown removed from surrounding valve
structures.
[0018] FIGS. 11-14 are views of the linkage mechanism in different
operating positions.
[0019] FIG. 15 is a cross section of the valve shown in FIG. 1.
DETAILED DESCRIPTION
[0020] An outline view of an air shutoff valve (ASV) 100 is shown
in FIG. 1. The ASV 100 includes a body 102 having an inlet portion
104, an outlet portion 106, a gate portion 108, and an actuator
portion 110. In the illustrated embedment, the ASV 100 is a
two-way, binary valve that can operate in an open position, in
which fluid communication is permitted between the inlet and outlet
portions 104 and 106, and a closed position, in which a gate valve
element 112 (shown in the cross section of FIG. 2) is moved by an
actuator and linkage mechanism within the actuator portion 110 to a
position that blocks fluid communication between the inlet and
outlet portions 104 and 106. Stated differently, the ASV 100
operates between an armed state, in which it stand ready to close
if needed, and a triggered state, in which the ASV 100 is closed to
prevent engine operation. As shown, the inlet portion 104 includes
a female bore 114 that accepts therein an air pipe (not shown)
carrying an engine inlet air stream during operation, but any other
connection arrangement can be used. The outlet portion 106 includes
a flange 116 that is mountable with fasteners to an intake manifold
(not shown) of an engine.
[0021] An air passage 118 (FIG. 2) connects the inlet and outlet
portions 104 and 106 and extends through the body 102 to carry the
inlet air stream from the female bore 114 to an opening in the
flange 116. The flange 116 is exemplary of an air connection to the
body 102 of the valve and can be replaced by any other appropriate
connection structure. In the illustrated embodiment, when the gate
112 is in the closed position, fluid transfer through the air
passage 118 is blocked or prevented. When in the open position, the
gate 112 is retracted into the body 102 to allow the relatively
unobstructed passage of fluids through the air passage 118. The
gate 112 has a generally cylindrical shape that matches the
circular cross sectional flow area of the air passage 118, but
other shapes can be used.
[0022] During operation, the gate 112 may be raised or lowered,
similar to a guillotine, with respect to the air passage 118 to
open or block the air passage 118. As shown in FIG. 2, and also in
at least FIGS. 3 and 4, the gate 112 is connected to a lift rod
120, which pulls the gate 112 from the closed position to the open
position, shown in FIG. 2, and maintains the gate 112 in the lifted
position. The lift rod 120 is connected to a chain 122 that
meshably engages a sprocket 124 that pivots around a lift axle 126.
As can be appreciated, the chain/sprocket arrangement shown herein
is exemplary and can be replaced by another mechanical transmission
arrangement such as a cable interacting with a pulley of any other
tension carrying member. The lift axle 126 serves as the axis of
rotation for the sprocket 124 and is perpendicular to a plane
defined by a retention pin axis, and also a lift rod axis and an
actuator axis. The lift and actuator axes are parallel and are both
perpendicular to the retention pin axis. The lift, actuator and
retention pin axes are coplanar. At one end, external to a cover
128, the lift axle 126 includes a driver 130, which is formed as a
hexagonal nut and which can be manually turned to reset or lift the
gate 112 to open the ASV 100 while the ASV 100 in a closed
position.
[0023] To activate or close the ASV 100, a signal may be provided
to activate an actuator 132. The actuator 132, which is embodied in
the illustrated device as an electrical solenoid actuator, includes
a release pin 134 in an extended position. Activation of the
actuator 132 causes the release pin 134 to retract. When in the
default extended position, the release pin 134 is disposed within
an opening 136 in a retention pin 138. As also shown in FIGS. 3 and
4, the retention pin 138 is slidably and reciprocally mounted
within the ASV 100 in a perpendicular orientation relative to the
release pin 134. The retention pin 138 is also spring loaded by two
springs 140 (FIG. 4), which are shown here as coil springs that are
kept in a compressed state while the release pin 134 is engaged in
the opening 136 of the retention pin 138. As can be appreciated,
the springs 140 can be replaced by at least one spring. Moreover,
while two springs are shown, any other resilient element or set of
elements can be used, including pneumatic and/or hydraulic
actuation or tension devices. The spring restore force of the
compressed springs 140 is communicated to the retention pin 138 via
a saddle 142.
[0024] When a signal is received at the actuator 132 to trigger or
energize the ASV 100 to close, an electrical signal causes the
actuator 132 to energize, which operates to retract the release pin
134 towards the actuator 132 by a sufficient distance such that the
release pin 134 clears the opening 136 and removes a retention that
opposes the restore spring force of the springs 140. With no
opposition to the spring force, the retention pin 138 snaps away
from the springs 140 and the lift rod 120 of the gate 112 (towards
the right, in the orientation shown in FIG. 2).
[0025] When the retention pin 138 moves towards the lift rod 120,
an interference between a tip 144 of the retention pin 138 and an
elongate slot 146 formed in the lift rod 120 removes a mechanical
retention of the gate 112 in the lifted position, which permits the
gate 112 to drop into the air passage 118. Motion of the gate 112
in the direction into the air passage 118 is effected by two lift
springs 148, which are disposed in bores 150 formed in the gate
portion 108 of the body 102 and which are in contact with the gate
112 and maintained in a compressed state when the gate 112 is in a
lifted or open position. While two lift springs 148 are shown, a
single or at least one spring can be used. Moreover, the one or two
lift springs may be replaced by another resilient element that
provides a restoring force when compressed, including passive
elements, e.g., that are made of collapsible and resilient
materials such as rubber, or active elements such as pneumatic
and/or hydraulic actuators and the like. When the retention pin 138
is retracted sufficiently for the tip 144 to clear the elongate
slot 146, as can be seen in FIG. 9, the gate 112 is free to drop
and moves towards the closed position by force of the lift springs
148. In the illustrated embodiment, a handle 152 (FIG. 2) attached
to an end of the solenoid actuator rod opposite the release pin 134
may be manually pulled to retract the release pin 134 and cause the
release of the gate 112 as described above.
[0026] When the ASV 100 is in the triggered or closed position, it
may be reset or rearmed manually. To accomplish this, a user may
engage the driver 130, for example, with a wrench, and turn the
driver 130 in a resetting or winding direction, for example, in a
clockwise direction in accordance with the orientation of parts
shown in FIG. 10. The driver 130 is rotatably connected with the
lift axle 126 such that rotation of the driver 130 causes the
sprocket 124 to also rotate. For example, when rotating the driver
130 in the direction for resetting the valve, the sprocket 124 in
the orientation shown in FIG. 2 will rotate clockwise to wind the
chain 122 onto the sprocket 124 and thus pull on the lift rod 120
to raise the gate 112.
[0027] A sequence of positions for raising the gate 112 or, stated
differently, for resetting the ASV 100 is shown in FIGS. 11-14. In
reference to these figures, it can be seen that the sprocket 124 is
rotated to lift the gate 112 and to also reset an armed position
for the retention pin 138, similar to the cocking mechanism for a
gun. In a first position, shown in FIG. 11, the sprocket 124 is at
its left most rotational position as the springs 148 (FIG. 9) have
already pushed the gate 112 to its lowermost or closed position. In
this position, the chain 122 has a minimal length of engagement
with the sprocket 124 as the lift rod 120 is in its most extended
position with respect to the actuator portion 110. Rotation of the
sprocket 124 is limited by a stop 154 that is engaged by a pawl
156. The pawl 156 has an elongate shape and a contoured tip 158.
The pawl 156 is connected to and arranged to rotate along with the
sprocket 124 such that the contoured tip 158 sweeps an arc at a
radius that lies beyond an outer periphery of the sprocket 124 as
the sprocket rotates.
[0028] For resetting the ASV 100, the sprocket 124 and pawl 156 are
rotated in unison by about 180 degrees from the stop 154 until the
tip 158 contacts a contoured notch 160 in the retention pin 138.
The notch 160 includes a push surface 162, which is disposed
perpendicularly relative to a longitudinal axis, A, of the
retention pin 138, along which the retention pin 138 can slide, as
described above, and a clearance surface 164, which is disposed at
an angle relative to the longitudinal axis A. As can be seen in
FIG. 12, as the pawl 156 is rotated, the tip 158 is swung into the
notch 160 and contacts the push surface 162. Continued rotation of
the driver 130 and, thus, continued rotation of the sprocket 124
and the pawl 156 will cause the tip 158 to push into and begin
moving the retention pin 138 towards the lift rod 120, while the
springs 140 (FIG. 4) are being compressed as they resist the
motion. At the same time, rotation of the sprocket 124 also causes
a lifting of the gate 112 as the chain 122 is wound over an
increasing segment of the sprocket 124.
[0029] At the position shown in FIG. 12, the tip 144 of the
retention pin 138 begins to enter the elongate slot 146 at its top
portion in the lift rod 120. Continued rotation of the sprocket 124
inserts a larger portion of the retention pin 138 into the slot 146
as the lift rod 120 continues its motion such that, in the position
shown in FIG. 13, the tip 144 of the retention pin 138 has been
fully inserted into the elongate slot 146 and is disposed at a
bottom portion thereon, in the orientation shown in FIG. 13. While
in this over-travel position, the retention pin 138 is not yet
retaining the lift rod 120 and gate 112, but is mechanically
positioned to prohibit a downward motion of the gate 112. Moreover,
at this position, the release pin 134 is allowed to snap into its
opening in the retention pin 138 and lock its position.
[0030] When force on the sprocket 124 is relaxed following the
locking of the release pin 134 into the retention pin 138, which is
usually verified by the user by an audible sound or "click," the
sprocket 124 begins to rotate in the opposite direction
(counter-clockwise, in the orientation shown in FIG. 14) at it is
pulled by the chain 122. The force on the chain 122 results from
elongation of the now compressed springs 148 (FIG. 9) and the force
they apply on the chain 122 through the body of the gate 112 and
the lift rod 120. So as not to interfere with the retention pin 138
that is now locked in position, the pawl 156 is allowed to swing
out of the notch 160 by providing a clearance between the tip 158
and the clearance surface 164, as shown in FIG. 14. This
counter-rotation of the sprocket 124 and pawl 156 stops when the
top of the elongate slot 146 engages the top of the tip 144 of the
retention pin 138, in the position shown in FIG. 14, and also in
the enlarged detail shown in FIG. 3.
INDUSTRIAL APPLICABILITY
[0031] The present disclosure is applicable to internal combustion
engines and, more particularly, to ASV valves disposed to fluidly
isolate engine cylinders from incoming air to prevent undesired
operation of the engine.
[0032] Various structures for arming and resetting the ASV 100 are
described above. The ASV 100 further includes additional structures
and features that improve its performance and increase its service
life. One such feature is a position sensor 202, which can be
mounted on the cover 128. The position sensor 202, which can be
embodied as a proximity sensor, is arranged to sense a target 204
and provide a signal when the target 204 is in a position at which
the gate 112 is locked in its open position, as shown in the
enlarged detail of FIG. 10. In the embodiment shown, the target 204
is a flat surface on a metal protrusion or shelf that is oriented
perpendicular to a plane defined by the sprocket 124 and is
positioned at a radial location relative to the sprocket 124 that
causes the target 204 to be disposed in front of the sensor 202
when the gate 112 is in its locked open or armed position.
[0033] Another feature of the ASV 100 includes an expansion chamber
206 and two annular sealing surfaces 208, which form a figure "8"
and which discourage ingress of compressed air in the air passage
118, which may also contain other gasses such as recirculated
exhaust gas and/or a gaseous engine fuel, into a cavity that houses
the sprocket 124, chain 122 and a portion of the actuator 132. As
shown in FIG. 5, the expansion chamber 206 is a blind chamber or
cavity formed in the body 102 that is can enclose the gate 112 when
the gate 112 is in its open position. The gate 112 includes two
face seals 210, one on either side of the gate 112, each of which
having a generally circular shape that surrounds a periphery of the
gate 112, as shown in FIGS. 6 and 15.
[0034] During operation, the gate 112 can form a complete seal
around its entire periphery and on both its upstream and downstream
sides relative to the air passage 118. In the event any air or
gas/air mixture leaks past the seals 210, especially when the gate
112 is in its open position, the expansion chamber 206 will serve
to cool, expand and condense any fluids that are dissolved in the
inlet air mixture to avoid contamination, corrosion and damage to
the components operating the gate opening mechanism. For example,
the inlet air mixture can include water vapors and also combustion
by-products when exhaust gas recirculation is used, which
by-products can include Sulphur oxides.
[0035] The seals 210 can be string seals accommodated in a channel,
and may be formed by over-molding a seal material, such as a
fluoro-elastomer, directly onto a gate 112, whereby both sides of
the seal 210 can be formed in a single injection molding operation
where the material passes from one side of the gate to the other
through molding channels 212 formed peripherally around the gate
112, as shown in the cross section through the gate 112 in FIG. 9.
In an alternative embodiment, the seals 210 may be made of a
different material such as copper, graphite, ceramics and the like,
which have an acceptable sealing performance and can withstand
operation and maintain their sealing properties after prolonged
operation at higher temperatures, for example, 300 deg. C., even in
the presence of corrosive substances, without appreciable loss of
their sealing ability.
[0036] For avoiding rattling and wear of the gate 112 when in the
open or armed position due to vibration during operation, the ASV
100 further includes a plurality of resilient rollers 214. The
placement of the rollers 214 for the illustrated embodiment can be
seen in FIG. 15 from a front perspective, in the cutaway view of
FIG. 8 from a top perspective, and in cross section from the front
perspective in FIG. 9. The rollers 214 form a central channel 216
that engages a ridge 218 of the gate 112 such that motion and/or
rotation in any direction except for the linear direction in which
the gate lowers (downward, in the orientation of FIG. 9) is
prevented or dampened by the resilience of the material of the
rollers 214, which may be made of rubber, PTFE, Viton.RTM.,
silicone, or the like.
[0037] To improve the operation of the ASV 100, the sliding
mechanism between the gate 112 and the gate portion 108 of the body
102 includes a self-centering mechanism that ensures smooth and
reliable valve activation regardless of installation or operation
orientation of the ASV 100. More specifically, the gate 112
includes two diametrically opposite arms 220 (FIG. 6), which
protrude radially with respect to the gate 112 and which interact
with guides 221 (FIG. 9) that are slidably disposed within the
bores 150. The guides 221 matingly engage contoured surfaces 222
formed on each of the arms 220. The contoured surfaces 222 have a
generally smooth concave shape, which approximates a circular
segment such that an axial force applied by the springs 148 onto
the gate 112 through the guides 221 and the arms 220 tends to
center the guides 221 within the bores 150. As can be seen from
FIGS. 9 and 15, the guides 221 also act as spring guides for the
springs 148 and are thus subject to motion by a spring force when
the springs 148 are extending, which motion is transferred to the
gate 112.
[0038] For facilitating assembly of the various components in the
ASV 100, a bore 224 is provided in the body 102. The bore 224,
which is plugged during operation of the ASV 100, is positioned
along the air passage 118 at a position that overlaps the gate 112
and is disposed at a location that is diametrically opposite the
lift rod 120. In this way, a tool, for example, a slender rod or
bolt, can be inserted through the bore 224 and push the gate 112
towards its open position, and retain the same in that position
while the remaining structures such as the sprocket 124 and chain
122 can be assembled.
[0039] For prolonging the service life and improving the viability
and operation of the actuator 132, the ASV 100 includes heat
shields 226 that at least partially surround the actuator 132 to
shield the same from heat that may be emanating from the body 102
of the ASV 100 during operation. Moreover, the actuator 132 is
placed such that the axis along which the retention pin 134 is
actuated is parallel with the axis along which the gate 112 can
move relative to the body 102. In this way, the length and
orientation of the mechanical path of transmission of motion can be
reduced and the actuator 132 can be placed closer to a center of
mass of the ASV 100, which reduces the vibration and wear that the
actuator might otherwise be subjected to.
[0040] To help prevent galling and rattling of internal components
of the ASV 100 during operation, the ASV 100 further includes a
leaf spring 228 that extends generally radially from the sprocket
124 and is disposed at a partially compressed between the sprocket
124 and a top surface of the lift rod 120, as shown in FIG. 2. Any
other retention structure can be used in place of the leaf spring
228 to provide a resilient stop member to prevent or dampen
vibration of the sprocket 124 and surrounding structures of the ASV
100. In this way, rotation of the sprocket 124 due to vibration
during operation of the ASV 100 is minimized or avoided.
[0041] It will be appreciated that the foregoing description
provides examples of the disclosed system and technique. However,
it is contemplated that other implementations of the disclosure may
differ in detail from the foregoing examples. All references to the
disclosure or examples thereof are intended to reference the
particular example being discussed at that point and are not
intended to imply any limitation as to the scope of the disclosure
more generally. All language of distinction and disparagement with
respect to certain features is intended to indicate a lack of
preference for those features, but not to exclude such from the
scope of the disclosure entirely unless otherwise indicated.
[0042] Recitation of ranges of values herein are merely intended to
serve as a shorthand method of referring individually to each
separate value falling within the range, unless otherwise indicated
herein, and each separate value is incorporated into the
specification as if it were individually recited herein. All
methods described herein can be performed in any suitable order
unless otherwise indicated herein or otherwise clearly contradicted
by context.
[0043] The use of the terms "a" and "an" and "the" and "at least
one" and similar referents in the context of describing the
invention (especially in the context of the following claims) are
to be construed to cover both the singular and the plural, unless
otherwise indicated herein or clearly contradicted by context. The
use of the term "at least one" followed by a list of one or more
items (for example, "at least one of A and B") is to be construed
to mean one item selected from the listed items (A or B) or any
combination of two or more of the listed items (A and B), unless
otherwise indicated herein or clearly contradicted by context.
[0044] Accordingly, this disclosure includes all modifications and
equivalents of the subject matter recited in the claims appended
hereto as permitted by applicable law. Moreover, any combination of
the above-described elements in all possible variations thereof is
encompassed by the disclosure unless otherwise indicated herein or
otherwise clearly contradicted by context.
* * * * *