Rotary actuator system for controlling valve actuation in an internal combustion engine

Abstract

A system for controlling actuation of an engine valve includes a pivot and a torsion spring having a first leg and a second leg operably connected to the pivot. A lever arm is adjustably attached to the pivot and extends away from the pivot and is further reciprocally rotatable about a pivot axis of the pivot relative to a motion transfer member between a retracted position and an extended position. Further, a housing is provided having a pivot bore formed therein in which the pivot is rotatably disposed. The housing further includes a first opening and a second opening intersecting the pivot bore such that the first leg and the second leg extend out of the first opening and the lever arm extends out of the second opening. When a first force is applied to the lever arm by the motion transfer member, the first force maintains the lever arm in the extended position.

Description

Technical Field

[0001] This disclosure relates generally to internal combustion engines, and more particularly to rotary actuator systems for controlling valve actuation in such internal combustion engines. Background Technology

[0002] Actuators are well known in the art and can include various means configured to achieve movement and / or operation of another mechanism. For example, in the field of internal combustion engines, actuators typically include a piston capable of holding two positions: a spring-biased retracted state and a hydraulically controlled extended state, in which the piston does not affect the movement / operation of the other mechanism, and in the hydraulically controlled extended state, the piston does affect the movement / operation of the other mechanism.

[0003] Examples of this type of internal combustion engine are as follows: Figure 1 As shown, Figure 1 This is a partial schematic diagram of an internal combustion engine 100 according to this disclosure, including a cross-sectional view of the engine cylinder 102 and the associated valve actuation system. Although Figure 1 A single cylinder 102 is shown, but this is merely for illustrative purposes; and it should be understood that an internal combustion engine typically includes multiple such cylinders driving a crankshaft (not shown). A piston 104 is disposed in the engine cylinder 102, and the piston reciprocates repeatedly during forward power operation of the cylinder 102 (i.e., fuel combustion to drive the piston 104 and the transmission system) and engine braking operation (i.e., using the piston 104 to compress air and absorb power through the transmission system). At the top of each cylinder 102, there may be at least one intake valve 106 and at least one exhaust valve 108, which are successively biased to their respective closed positions by corresponding valve springs 105, 107. The intake valve 106 and exhaust valve 108 are opened and closed to provide communication with the intake passage 110 and the exhaust passage 112, respectively. The valve actuation force for opening the intake valve 106 and exhaust valve 108 is transmitted by corresponding valve mechanisms 114, 116. Furthermore, such valve actuation forces (indicated by dashed arrows) can be provided by corresponding primary and / or auxiliary motion sources 118, 120, 122, 124 (such as rotary cams). As used herein, the descriptive term “primary” refers to the so-called primary event engine valve motion, i.e., the valve motion used during positive power generation; however, the descriptive term “auxiliary” refers to other engine valve motions used for purposes other than positive power generation (e.g., compression release braking, blow-off braking, cylinder decompression, brake gas recirculation (BGR), etc.) or motions other than positive power generation (e.g., internal exhaust gas recirculation (IEGR), variable valve actuation (VVA), Miller / Atkinson cycle, swirl control, etc.).

[0004] Valve mechanisms 114, 116 may include any number of mechanical, hydraulic, hydraulic-mechanical, electromagnetic, or other types of valve mechanism elements known in the art. For example, each of valve mechanisms 114, 116 may include one or more cam followers, push tubes, rocker arms, valve crossarms, etc., for transmitting valve actuation motion to valves 106, 108. Additionally, one or more actuators 126, 128 may be included in any one or both of valve mechanisms 114, 116, thereby partially controlling or modifying the valve actuation motion normally transmitted by valve mechanisms 114, 116. Typically, such actuators 126, 128 are under the control of corresponding actuator controllers 130, 132 (such as solenoids, electromagnetic linear actuators, etc., for controlling hydraulic fluid), which in turn are controlled by an engine controller 134. This engine controller may include any electronic, mechanical, hydraulic, electrohydraulic, or other type of control device for communicating with and controlling the operation of the actuator controllers 130, 132. For example, the engine controller 134 may be implemented using a microprocessor and a corresponding memory storing executable instructions, as known in the art, for implementing the desired control functions. It should be understood that other functionally equivalent implementations of the engine controller 134 (e.g., appropriately programmed application-specific integrated circuits (ASICs), etc.) may be equivalently employed. A specific function employing such actuators is cylinder decompression or release braking, but those skilled in the art will understand that other applications are well-known.

[0005] Figure 2 and Figures 3A to 3C This is a schematic diagram of a rotary actuator used in an internal combustion engine according to prior art. For example, U.S. Patent No. 4,340,017 shows an example of such a rotary actuator for cylinder decompression. Figure 2 As shown, the valve mechanism 200 includes a motion source 202 as known in the art, a motion transmission member 208, and one or more engine valves 210. As further shown, a rotary actuator 206 is supported by a stationary object 204 relative to the motion transmitted by the motion transmission member 208 / the movement of the motion transmission member. In this configuration, the rotary actuator 206 is operated to selectively hold the motion transmission member 208 in a desired position (or not, as appropriate), thereby controlling the engine valves 210, for example, in an open position during cylinder decompression or blow-off engine braking.

[0006] The operating principle of the rotary actuator of the type described in patent '017 is relative to... Figures 3A to 3CA further description will be given. Specifically, the rotary actuator 300 includes a rotatable pivot 302 having a rotational axis 304. Additionally, the rotary actuator 300 includes a lever arm 306 attached to the pivot 302. In this example, the outer edge of the pivot 302 is maintained at a distance D from the movable member 308 (e.g., a motion transmission member of a valve mechanism). A portion of the lever arm 306 extends beyond the length X of the outer edge of the pivot 302, where X > D. In the illustrated example, the movable member 308 includes a piston located in a bore 310 defined in a housing 312. However, those skilled in the art should understand that the movable member 308 need not be limited to the illustrated piston arrangement and can take any of a variety of forms. As Figure 3A shown, the pivot 302 and the lever arm 306 rotate about the axis 304 relative to the vertical direction at an angle θ1 > 0, resulting in a clearance (or clearance space) L being established above the upper surface 309 of the movable member 308, thereby preventing any physical interaction between the actuator 300 and the movable member 308. In this state, the actuator 300 is considered to be in a "retracted", "closed", or "deactivated" state.

[0007] On the other hand, Figure 3B shows the interaction between the actuator 300 and the movable member 308 when the rotatable pivot 302 and the lever arm 306 have been rotated 320 such that the lever arm 306 is vertically oriented (i.e., θ2 = 0). In this state, the actuator 300 is considered to be in an "extended", "energized", or "activated" state. When the lever arm 306 is vertically oriented as shown, the contact between the lever arm 306 and the movable member 308 results in a maximum linear displacement 322 that is equal to the difference between the length of the lever arm 306 and the distance of the pivot 302 from the upper surface 309 (i.e., X - D). It should be understood that at some angle θ3, where θ1 > |θ3| > θ2, the lever arm 306 can contact the upper surface 3 of the movable member 308 such that the movable member is still displaced 322 by an amount less than Figure 3B the maximum value shown in. In Figure 3C an example is shown in which the lever arm 306 is rotated at an angle θ3, which results in a new effective lever arm length X' = X * cos(θ3). To the extent that X' < X, the resulting clearance space X' - D will also be less than Figure 3B the clearance space X - D shown in. As described in more detail below, such an intermediate rotation as shown in Figure 3C can cause a torque to be generated in the actuator 300, which can be used to control the operation of the actuator 300.

[0008] Although such actuators have proven to be useful, further actuator designs are needed for different applications. Summary of the Invention

[0009] This disclosure describes a system for controlling the actuation of engine valves in an internal combustion engine, the engine including such engine valves and a valve actuation motion source operatively connected to the engine valves via at least one motion transmission member. Specifically, such a system includes a pivot and a torsion spring having a first leg and a second leg operatively connected to the pivot. A lever arm is adjustably attached to the pivot and extends away from the pivot, the lever arm being further reciprocating between a retracted position and an extended position relative to the motion transmission member about a pivot axis of the pivot. Furthermore, a housing is provided having a pivot bore formed therein, in which the pivot is rotatably disposed. The housing also includes a first opening intersecting the pivot bore and a second opening intersecting the pivot bore, such that the first leg and the second leg extend out of the first opening and the lever arm extends out of the second opening. In the retracted position, the lever arm has substantially no effect on the actuation of the engine valve, and in the extended position, the lever arm is positioned to contact the motion transmission member, thereby controlling the actuation of the engine valve. When the first force is applied to the lever arm by the motion transmission component, the first force holds the lever arm in the extended position.

[0010] In one embodiment, the biasing element is configured to apply a biasing force to rotate the lever arm to the retracted position, wherein the first force applied by the motion transmission component is sufficient to overcome the biasing force applied by the biasing element.

[0011] In another embodiment, a second opening in the housing defines a first stop surface and a second stop surface, wherein the first stop surface is configured to define the retracted position and the second stop surface is configured to define the extended position. In this embodiment, the second stop surface is configured to position the lever at a non-zero angle relative to the direction of application of the first force. Furthermore, the lever arm may include a rotating cup disposed at the distal end of the lever arm, wherein the rotating cup is configured to contact the first stop surface when the lever arm is in the retracted position and to contact the second stop surface when the lever arm is in the extended position.

[0012] In another embodiment, the first force is the closing force applied by the engine valve spring to the engine valve and thus to the motion transmission component.

[0013] In yet another embodiment, the system may further include: a linear actuator having an activated state and a deactivated state; a sliding rack slidably mounted on a fixed housing and operatively connected to the linear actuator; and a biasing element configured to bias the sliding rack to an initial position when the linear actuator is in the deactivated state, wherein when the linear actuator is in the activated state, the sliding rack moves to a fully displaced position against the bias of the biasing element. In one embodiment, the biasing element may include a spring disposed between the linear actuator and the sliding rack. In this embodiment, a first leg and a second leg of the torsion spring are configured to intersect a slot formed in the sliding rack. In the initial position and when the first force is not applied to the lever arm by the motion transmission member, the slot engages the first leg of the torsion spring and positions the lever arm in the retracted position. In the initial position and when the first force is applied to the lever arm by the motion transmission member, the slot in the first leg of the torsion spring induces a load to position the lever arm in the retracted position when the first force is removed from the lever arm. In the fully displaced position and when the first force is not applied to the lever arm by the motion transmission member, the slot engages the second leg of the torsion spring and positions the lever arm in the extended position. Furthermore, in the fully displaced position and when the first force is applied to the lever arm by the motion transmission member, the slot in the second leg of the torsion spring induces a load to position the lever arm in the extended position when the first force is removed from the lever arm. Additionally, the slot in the sliding rack may include an H-shaped slot having a first longitudinal channel and a second longitudinal channel, wherein the first leg of the torsion spring intersects the first longitudinal channel and the second leg of the torsion spring intersects the second longitudinal channel.

[0014] In the currently preferred embodiment, the movement of the housing relative to the motion transmission member is fixed. Alternatively, the housing may be provided by another motion transmission member of the at least one motion transmission member. Attached Figure Description

[0015] The foregoing and other features and advantages will be discussed in detail in the following non-limiting description of a particular embodiment, in conjunction with the accompanying drawings, wherein:

[0016] Figure 1 This is a schematic partial cross-sectional view of an internal combustion engine, showing a typical deployment of actuators according to the prior art;

[0017] Figure 2 It is a block diagram of an internal combustion engine including a rotary actuator system, based on existing technology;

[0018] Figures 3A to 3C The operating principle of a rotary actuator according to the prior art is illustrated schematically.

[0019] Figure 4A and Figure 4B A first embodiment of a rotary actuator according to the present disclosure and configured for actuating an engine valve is shown;

[0020] Figure 5A and Figure 5B A second embodiment of the rotary actuator according to this disclosure is shown;

[0021] Figures 6 to 9B It is a combination Figure 5A and Figure 5B Perspective and detailed views of the cylinder decompression system of the second embodiment of the rotary actuator;

[0022] Figures 10A to 10D yes Figure 6 A cross-sectional view of a portion of the cylinder decompression system, showing Figure 5A and Figure 5B Operation of the second embodiment of the rotary actuator;

[0023] Figure 11 It shows Figure 6 The flowchart for the decompression start-up of the cylinder decompression system;

[0024] Figure 12 It shows according to Figure 11 The graph shows the valve lift curves for multiple cylinders in a decompression start-up configuration.

[0025] Figures 13A to 13F yes Figure 6 A perspective view of the cylinder decompression system, showing the... Figure 11 The various operating points for decompression startup are shown;

[0026] Figure 14 It shows Figure 6 A flowchart for decompression shutdown of the cylinder decompression system;

[0027] Figure 15 It shows according to Figure 14 The graph shows the valve lift curves for multiple cylinders that are depressurized and shut down.

[0028] Figure 16 This is a block diagram illustration of an internal combustion engine including a rotary actuator system according to an embodiment of this disclosure; and

[0029] Figure 17 It is based on Figure 16 A perspective view of the rocker arm in the implementation scheme. Detailed Implementation

[0030] As used herein, phrases substantially similar to "at least one of A, B, or C" are intended to be interpreted as disjunctive terms, requiring A or B or C, or any combination thereof, unless the context otherwise indicates or implies. Furthermore, phrases substantially similar to "at least one of A, B, and C" are intended to be interpreted as conjunctions, requiring at least one of A, at least one of B, and at least one of C, unless the context otherwise indicates or implies. In addition, the term "substantially" or similar terms requiring subjective comparison are intended to mean "within manufacturing tolerances," unless the context otherwise indicates or implies. Unless otherwise stated, references to absolute position qualifiers (such as terms "front," "back," "top," "bottom," "left," "right," etc.) or relative position qualifiers (such as terms "above," "below," "upper," "lower," etc.) or direction qualifiers (e.g., "horizontal," "vertical," etc.) in this invention are made with respect to the directions shown in the figures.

[0031] Now for reference Figure 4A and Figure 4B A first embodiment of the rotary actuator 400 is shown in conjunction with the valve crossarm 430. In this embodiment, the actuator 400 includes a pivot body 402 rotatably mounted on a pivot 404. As shown by vertical line 405, the axis of rotation of the pivot 404 is aligned with contact surfaces 432 formed on the valve crossarm 430 and the engine valve (not shown). Similar to Figure 3A and Figure 3B In one embodiment, lever arm 406 is implemented as a clearance adjusting screw fixed to the housing via a suitable threaded hole formed in pivot body 402. As known in the art, a clearance adjusting screw 408 is provided to hold a selected portion 410 of the clearance adjusting screw 408 fixedly (yet adjustablely) extending generally out of pivot body 402 along the direction of valve crossarm 430 and contact surface 432. As further shown, a rotating cup 412 (sometimes referred to in the art as an "elephant foot" or "e-foot") is rotatably mounted on the spherical end of clearance adjusting screw 406. When the rotary actuator 400 is in… Figure 4A In the closed / retracted / disabled state shown, the rotating cup 412 may remain in contact with the contact surface 432 as shown but without otherwise causing any movement of the valve crossarm 430; or the clearance space may be as shown. Figure 3A and Figure 3B The implementation scheme is set up as shown. For example... Figure 4AAs further shown, when the actuator 400 is in the closed / retracted / disabled state, the pivot cup 412 is laterally deviated from the axis of rotation of the pivot 404. Rotation of the pivot body 402 can be selected by operating a second or control lever arm 414 operably coupled to the pivot body 402. Additionally, to hold the rotary actuator 400 in the closed / disabled state, a compliant element 416, such as a spring, can be provided to bias the control lever arm 414 (in this case, clockwise as shown).

[0032] like Figure 4B As shown, the rotary actuator 400 can be placed in the on / extended / activated state by applying a suitable force 440 (i.e., sufficient to overcome the bias applied by the compliant element 416) to the control lever arm 414, thereby causing the pivot body 402 to rotate as shown. Upon transitioning to the on / extended / activated state, the rotating cup 412 is laterally displaced 444 as shown to better align with the contact surface 432. Furthermore, the rotation of the lever arms 406, 410 causes a vertical displacement 442 of the contact surface 432, which in turn causes a clockwise rotation of the valve crossarm 430 (e.g., ...). Figure 4B (As shown). To control the rotation of lever arm 414, elastic element 416 is placed under increased tension, which causes rotary actuator 400 to rotate back. Figure 4A The closed / retracted / disabled states are shown. However, in the currently preferred embodiment, the rotation of lever arms 406, 410 fully extends beyond the vertical direction (e.g., Figure 4B As shown), the additional biasing force applied by the valve spring (not shown) to the valve crossarm 430 via the intermediate engine valve generates a counterclockwise torque 446. If the torque generated by the valve spring to the lever arms 406, 410 is stronger than the torque generated in the opposite direction by the elastic element 416, the rotary actuator 400 will remain in the on / extended / activated state until the torque 446 generated by the valve spring is removed from the rotary actuator 400, thereby allowing the elastic element to rotate the pivot body 402 again and returning the rotary actuator 400 to the off / retracted / disabled state.

[0033] Now for reference Figure 5A and Figure 5B A second embodiment of the rotary actuator 500 is shown. In this embodiment, the pivot body 502 is rotatably mounted in a housing 530. The housing 530 is preferably a stationary or fixed body relative to the rotation of the rotary actuator 500 and any movement relative to interacting motion-transmitting components (e.g., valve crossarms, rocker arms, etc.). For example, in the context of an internal combustion engine, the housing 530 may be integrated with or fixedly mounted thereto by a cylinder head or similar structure. Alternatively, in embodiments described in further detail below, the housing 530 may be integrated with a rocker arm, etc.

[0034] In the illustrated example, pivot 502 is configured to insert into a hole 509 formed in housing 530, allowing pivot 502 to rotate freely about the central axis of hole 509. The closed end of hole 509 restricts insertion of pivot 502 into the hole. A lever arm 506 in the form of a clearance adjusting screw is disposed in a threaded hole 507 formed in pivot 502. Figure 4A and Figure 4B In one embodiment, the gap adjusting screw 514 and, in this case, the spacer 516, can be configured to adjust the effective length of the lever arm 506. A first opening 511 in the housing 530 intersects with a hole 509, such that once the pivot body is inserted into the hole 509, the lever arm 506 can be inserted into the threaded hole 507. A second opening 513 (in...) Figure 7 and Figures 10A to 10D (Best shown in the diagram) It is formed on the lower side of the housing 530 and intersects with the hole 509 at the point where the spherical end of the lever arm 506 protrudes from the threaded hole 507. The rotating cup 512 is provided on the spherical end of the lever arm 506. Figures 10A to 10D As further shown, the second opening 513 defines a first stop surface 515 and a second stop surface 517, which are configured to interact with the rotating cup 512 to limit the rotation of the rotary actuator 500 in any direction, as described in further detail below.

[0035] The control lever arm 519 is configured as a torsion spring 520. As described in more detail below, the use of the torsion spring 520 forms a compliant control lever arm, which partially integrates the above-described control lever arm relative to the control lever arm 519. Figure 4A and Figure 4B The function of the elastic element 216 is as follows: A torsion spring 520 is configured to insert into a recess 521 formed in the pivot body 502 and adjacent to a threaded hole 523, which is formed perpendicular to and concentric with the axis of rotation of the pivot body 502. A threaded cap 504 is provided, which mates with the threaded hole 523 and includes a longitudinally extending portion that, when the torsion spring 520 is fully inserted into the recess 521, inserts into the central opening of the coil of the torsion spring 520, thereby retaining the torsion spring in the recess 521. Constructed in this way, the first leg 522 and the second leg 524 of the torsion spring 520 extend from a first opening 511 formed in the housing 530. The abutment of the torsion spring 520 defined by the first opening 511 and the sidewall 532 prevents the pivot body 502 from disengaging from the hole 509. Figure 5AAs shown, the torsion spring 520 is in a free or unloaded state. However, when the torsion spring 520 is inserted into the recess 521, the limiting sidewall of the recess 521 pushes the legs 522 and 524 inward, thereby placing the torsion spring in a preloaded or partially loaded state. As described below, the legs 522 and 524 of the torsion spring 520 can be used to control the rotation of the pivot 502 by selectively applying force to either leg 522 or 524. Furthermore, because the legs 522 and 524 are flexible, they can be controlled to generate a torque in the pivot 502 that is allowed to cause rotation of the pivot 502 only when an obstacle (e.g., a movable part to be actuated) to the rotary actuator 500 is removed.

[0036] Figures 6 to 9B Including combinations Figure 5A and Figure 5B Various illustrations of the cylinder decompression system of the second embodiment of the rotary actuator. Although the description provided below is in conjunction with a decompression system, those skilled in the art will understand that... Figures 6 to 9B The system shown can also be used for other purposes, such as, but not limited to, release braking operations. Figure 6 As shown, the cylinder decompression system includes a housing 600 having a plurality of rotary actuators 602-606 disposed therein. In one embodiment, the housing 600 is preferably mounted to the cylinder head such that the rotating cup 512 of each rotary actuator 602-606 is positioned above the corresponding valve crossarm (e.g., as shown). Figure 4A , Figure 4B and Figures 10A to 10D As shown in the diagram, rotary actuators 602-606 can be controlled to actuate the valve crossarm to keep the corresponding engine cylinder in a decompression state. A linear actuator 608 and a sliding rack 610 are also mounted on the housing 600. The linear actuator 608, which may include an electromagnetic solenoid, is operably connected to the rack 610 such that operation of the linear actuator 608 in the start-up or energized state causes displacement of the rack 610 (to the right, as shown in the diagram). Figure 6 (As shown in the diagram). A biasing element 612 in the form of a compression spring is disposed between the linear actuator 608 and the rack 610 to cause the rack 610 to have the opposite displacement when the linear actuator 608 is not activated or de-energized, that is, to return the rack 610 to its original position. Figure 6 The starting position is shown (to the left).

[0037] like Figure 6 and Figure 8 As shown, the rack 610 includes a plurality of openings 810 slidably fixed to the housing 600 by mounting screws 812. Furthermore, as... Figure 7 and Figure 8As best illustrated, the legs 522, 524 of each torsion spring in the torsion spring 520 interact with corresponding slots 802 formed in the rack 610. In the presently preferred embodiment, the slots 802 are implemented in the form of H-shaped slots, each H-shaped slot including a first longitudinal channel 804 and a second longitudinal channel 806 corresponding to the first leg 522 and the second leg 524, respectively, wherein the longitudinal channels 804, 806 are defined by protrusions 808. Essentially, the legs 522, 524 of each torsion spring 520 act as pinions relative to the rack 610, whereby linear displacement of the rack causes rotation of the legs 522, 524. Figure 9A and Figure 9B An example of this is shown in the figure.

[0038] exist Figure 9A In the figure, rack 610 is shown in its nominal or starting position, i.e., when biased to the maximum leftward distance allowed by opening 810 by return spring 612 (as shown). In this case, the H-shaped slot also biases the first leg 524 of torsion spring 520 to the left, thereby retracting the rotating cup 512 into the second opening 513 of housing 600. Reference Figure 10A To further illustrate this situation, the bias applied to the first leg 524 (not shown) by the rack 610 causes the pivot body 502 to rotate counterclockwise until it is restricted by contact between the rotating cup 512 and the first stop surface 515 of the second opening 513. In this closed / retracted / disabled state, a clearance space is provided between the upper surfaces of the rotating cup 512 and the corresponding valve crossarm 1002.

[0039] exist Figure 9B In the figure, rack 610 is shown in a position where it is fully displaced by opening 810 (displaced to the right to the maximum extent as shown). In this case, the H-shaped slot allows the second leg 522 of torsion spring 520 (in) Figure 9B (Not visible in the center) is also offset to the right, causing the rotating cup 512 to extend from the second opening 513 of the housing 600. (Reference) Figure 10B To further illustrate this situation, the bias applied to the second leg 522 (not shown) by the rack 610 causes the pivot 502 to rotate clockwise until it is restricted by the contact between the rotating cup 512 and the second stop surface 517 of the second opening 513. In this on / extended / activated state, not only is the clearance space between the rotating cup 512 and the valve crossarm 1002 completely occupied from the closed / retracted / disabled state, but the extension of the rotating cup 512 out of the second opening 513 causes the displacement of the valve crossarm 1002 to a degree to which the rotation of the pivot 502 is not prevented by the contact between the rotating cup 512 and the valve crossarm 1002. Figure 10B and Figure 10C This shows when the rack 610 moves to, as Figure 9BThe fully extended state shown represents various transition states of the rotary actuator, assuming that the valve crossarm 1002 does not impede the movement of the rotary cup 512 or the rotation of the pivot body 502. Specifically, Figure 10B The pivot body 502 is shown at a rotation angle sufficient to initially contact the rotating cup 512 with the valve crossarm 1002, while Figure 10C The pivot body 502 is shown to be rotated at an angle such that the lever arm / clearance adjusting screw 506 is in a vertical position and the rotating cup 512 extends fully out of the second opening to initiate the downward displacement of the valve crossarm 1002.

[0040] refer to Figure 10D It was observed that the lever arm / clearance adjusting screw 506 rotated through Figure 10C The vertical alignment shown ensures that the large biasing force 1004 applied by the valve spring (not shown) to the valve crossarm and lever arm 506 generates a torque in the pivot 502 sufficient to maintain contact between the rotating cup 512 and the second stop surface 517. That is, the large biasing force 1004 is stronger than any biasing force that could be applied by the rack 610 to the first leg 524 of the torsion spring 520, which would otherwise be able to cause a counterclockwise rotation of the pivot 502 to return the rotary actuators 602-606 to their original positions. Figure 9A and Figure 10A The states shown are closed / retracted / disabled.

[0041] Now for reference Figure 11 , showing Figure 6 The flowchart for the decompression start-up of the cylinder decompression system. Figure 11 The processing procedure shown is preferably performed by a suitable processing device operatively connected to the relevant components (e.g., fuel injectors, solenoids, etc.) required to perform the function. Therefore, when it is desired to depressurize a cylinder in an internal combustion engine (e.g., when the engine is off), the processing procedure begins at step 1102, where fuel injection to the relevant cylinder is stopped and the linear actuator 408 is energized. Figure 6 In the illustrated embodiment, energizing the linear actuator 608 causes the rack 610 to displace to the right, and thus causes the actuator piston to retract (box 1104). As described above, this movement of the rack 410 causes the H-shaped slot to engage with the second leg 522 of each torsion spring 520 of the rotary actuators 602-606, allowing the pivot 502 to rotate freely, or loading the torsion spring 520 if the pivot 502 cannot rotate freely. Figures 13A to 13C To provide a more comprehensive description of this.

[0042] Figure 13A This shows what happens when the linear actuator 608 is energized. Figure 6The system. At this time, the rotating cups 512a-c corresponding to the first to third rotary actuators 602-606 retract, reflecting the closed / retracted / disabled state of the rotary actuators 602-606. In this state, the closed / retracted / disabled state of the rotary actuators 602-606 is further reflected in the fact that each pair of legs 522, 524 corresponding to the rotary actuators 602-606 rotates counterclockwise, that is, the control lever arm provided by each pair of legs 522, 524 causes the pivot body 502 to rotate in the same way, so that the rotating cups 512a, 512b, 512c retract. Figure 13B The diagram shows subsequent time points when the H-shaped slot in the rack 610 initially engages, respectively, corresponding to the second torsion spring legs 522a, 522b, and 522c of the first to third rotary actuators 602-606. Figure 13C This shows another subsequent point in time when rack 610 has completely shifted to the right. The second torsion spring legs 522a, 522b, and 522c are... Figure 13C The state at the point in time shown will depend on whether the rotating cups 512a, 512c, 512c are obstructed by their corresponding valve crossarms (not shown). For example, as Figure 13C As shown, it is assumed that the valve crossarms corresponding to the first rotary actuator 602 and the second rotary actuator 604 are positioned to impede the extension of the corresponding rotary cups 512a, 512b (i.e., the valves contacted by those valve crossarms are completely closed), while it is assumed that the valve crossarm corresponding to the third rotary actuator 606 is not positioned to impede the extension of the corresponding rotary cup 512c (i.e., the valve contacted by that valve crossarm is at least partially open). Therefore, the pivot 502 of the third rotary actuator 606 is allowed to rotate, thereby allowing the rotary cup 512c to extend as shown. Furthermore, the second torsion spring leg 522c of the third rotary actuator 606 remains unloaded because it can rotate together with its corresponding pivot 502. On the other hand, because the pivot 502 of the first rotary actuator 602 and the second rotary actuator 604 cannot rotate, the first torsion spring legs 522a, 522b are displaced due to the greater force applied to them by the rack 610, thereby applying a torque on the corresponding pivot 502.

[0043] Refer again Figure 11 At frame 1106, the opening of the engine valve previously closed at frame 1104 causes a gap between the corresponding valve crossarm and the rotating cup 512, which was previously prevented from opening by the valve crossarm. Further reference. Figure 13D and Figure 13E This needs to be explained. Figure 13DAt the indicated time point, it is assumed that the valve crossarm of the rotating cup 512a, which previously obstructed the first rotary actuator 602, has been displaced by the opening of its corresponding valve. Therefore, as shown, the torque applied to its pivot 502 by the second torsion spring leg 522a of the first rotary actuator 602 can cause rotation of the pivot 502, resulting in the extension of the rotating cup 512a and the displacement / unloading of its corresponding torsion spring 520. Similarly, in Figure 13E At the indicated time point, it is assumed that the valve crossarm of the rotating cup 512b, which previously obstructed the second rotary actuator 604, has been displaced by the opening of its corresponding valve. Therefore, as shown, the torque applied to its pivot body 502 by the second torsion spring leg 522b of the second rotary actuator 604 can cause the pivot body 502 to rotate, thereby resulting in the extension of the rotating cup 512b and the displacement / unloading of its corresponding torsion spring 520.

[0044] refer to Figure 12 This sequential on / off / starting of each rotary actuator is further illustrated, as well as the subsequent decompression of the engine cylinders by maintaining the engine valves in the open position. Specifically, Figure 12 The valve lifts 1202-1212 for six different cylinders of a six-cylinder engine are shown; more specifically, valve lift 1202 for cylinder 1, valve lift 1204 for cylinder 4, valve lift 1206 for cylinder 2, valve lift 1208 for cylinder 6, valve lift 1210 for cylinder 3, and valve lift 1212 for cylinder 5. At the time (crank angle) indicated by the vertical dashed line 1214, the linear actuator 608 is as described above. Figure 11 The step 1102 described above is energized. Then, before completing the valve lift 1206 of cylinder 2, the corresponding rotating cup 512 for each cylinder in the cylinder is fully extended or biased (by the corresponding torsion spring 520) so as to fully extend when setting the clearance with the valve crossarm. This is as follows Figure 12 As shown, the closing of the valve of cylinder 2 is prevented by the extension of the rotating cup of that cylinder 1216. Similarly, for each of the remaining cylinders (cylinders 1 and 4 not shown), similar time points 1218-1222 occur, where their corresponding valve crossarms are blocked, preventing the engine valves from closing completely and thus depressurizing those cylinders.

[0045] Refer again Figure 11 With the cylinder fully activated and decompression as described above, the process continues at block 1108, where the linear actuator 608 is de-energized (i.e., shut down or placed in its non-starting state). Therefore, as... Figures 13C to 13EAs shown, no force is provided to hold rack 610 in the rightmost position. Therefore, the force applied by return spring 612 causes rack 610 to bias to the left again until rack 610 contacts one or more of the first torsion spring legs 524a, 524b, 524c, such that the torsion from torsion spring 520 is balanced by the biasing force applied by return spring 512. The bias applied by torsion spring 520, opposite to the bias of return spring 612, generates a counterclockwise torque in pivot body 502 of rotary actuators 602-606. However, considering the larger clockwise torque generated by valve springs in pivot body 502, the torque generated by torsion spring 520 cannot rotate pivot body 602 to the closed / disengaged position. This situation persists as long as the torque generated by valve springs is present in pivot body 502.

[0046] Now for reference Figure 14 , showing Figure 6 The flowchart for decompression shutdown of the cylinder decompression system. Again, Figure 14 The processing illustrated is preferably performed by a suitable processing device operatively connected to the relevant components (e.g., fuel injectors, solenoids, etc.) required to perform the function. Thus, when it is desired to stop the decompression of the cylinders in the internal combustion engine (e.g., during engine start-up), the processing begins at step 1402, where the engine ignition switch (in this example) is turned on, causing the starter motor to begin starting the engine. Then, at block 1404, as the starter motor starts the engine, the various engine valves open in the usual manner, i.e., the rotating cam causes the rocker arm to reciprocate, which in turn causes the valve crossarms connected to the engine valves to reciprocate. When a gap appears between the valve crossarm and the rotary actuators 602-606 that are held in the on / extended / started state (or, in other words, when the obstruction provided by the valve crossarm preventing the rotary actuators 602-606 from changing to the closed / retracted / disabled state is removed), the rotary actuators 602-606 are allowed to change back to the closed / retracted / disabled state by means of the torque generated by the torsion spring 520 after the decompression start-up process is completed. Figure 13F This is like... Figure 15 As shown, at time point 1512 before decompression start-up, the various valve lifts are maintained at a constant opening height. The vertical line 1514 in the figure indicates the start-up time (crank angle) of the starter motor. Then, at each time point 1516-1522, the illustrated valve lifts are executed, thereby allowing the rotary actuators 602-606 to rotate back to their retracted positions and allowing each cylinder to resume normal compression operation.

[0047] Refer again Figure 14In the case of complete cylinder decompression as described above, the process continues at frame 1408, where the cylinder fuel supply is restored.

[0048] As previously stated, the rotary actuator according to this disclosure is not required to be mounted in a fixed housing, but can be mounted in a dynamic housing. Figure 16 An example like this is shown in the figure. Figure 16 It schematically shows something that is essentially similar to Figure 2 The valve mechanism 1600 of the embodiment differs in that the rotary actuator 1606 is included within the motion transmission member 1604, as shown. For example, the rotary actuator 1606 may be included in a rocker arm, valve cross arm, etc. Again, the rotary actuator 1606 can be controlled to selectively lose the motion generated by the motion source 1602, or to transmit the motion to any intermediate motion transmission member 1608 and engine valve 1610.

[0049] exist Figure 17 The text further illustrates the basis for... Figure 16 A specific example of the system is shown, illustrating a rocker arm 1702 with a motion receiving end 1704 and a motion applying end 1706 as known in the art. However, in this case, the rocker arm 1702 also has a rotary actuator 1710 mounted therein, which is substantially similar to the rotary actuator 500 described above. Specifically, the rocker arm 1702 has a transverse bore 1714 formed in the motion applying end 1706 of the rocker arm 1702, in which a pivot body 1712 is disposed. Also similar to the housing 530 described above, the rocker arm 1702 includes a first opening 1730 and a second opening (not shown) intersecting the bore 1714, such that components of the rotary actuator 1710 can extend out of the openings. In the illustrated example, this includes legs 1722, 1724 of a torsion spring 1720 extending out of the first opening 1730 and a rotating cup 1716 extending out of the second opening. Although not shown in Figure 17 As shown, but it should be understood that, similar to Figure 6 The linear actuator and rack system shown can be used to actuate torsion spring legs 1722 and 1724, which is a way to control the retraction / extension of rotary actuator 1710. However, in this case, the movement of the rack will be substantially parallel to the longitudinal axis of rocker arm 1702. Furthermore, the lengths of the torsion spring legs 1722 and 1724 need to account for the reciprocating movement of rocker arm 1702 so that legs 1722 and 1724 do not disengage from their corresponding racks.

[0050] Although specific embodiments have been described herein, those skilled in the art will understand that various modifications may be made without departing from the scope of this disclosure. For example, while the biasing element 612 is configured such that rotary actuators 602-606 are normally (i.e., when linear actuator 608 is de-energized) biased by rack 610 to their closed / retracted / disabled positions and switched to the on / extended / started positions by operation of linear actuator 608, this is not necessary. That is, the biasing element 612 may alternatively be configured such that rack 610 normally biases rotary actuators 602-606 to their on / extended / started positions, and operation of linear actuator 608 is required to switch them to their closed / retracted / disabled positions. Such a configuration can be used as a “safety interlock” such that deactivation of linear actuator 612 causes decompression of the relevant cylinder (and thus prevents power generation through the normal combustion cycle).

Claims

1. A system for controlling the actuation of an engine valve, the system comprising, in an internal combustion engine including the engine valve and a valve actuation motion source operatively connected to the engine valve via at least one motion transmission member: Pivot; A torsion spring having a first leg and a second leg operably connected to the pivot; A lever arm, which is adjustablely attached to and extends away from the pivot, and is capable of reciprocating between a retracted position and an extended position relative to the at least one motion transmission member about the pivot axis; and A housing having a pivot hole formed therein and a pivot rotatably disposed in the pivot hole, the housing further comprising a first opening intersecting the pivot hole and a second opening intersecting the pivot hole, such that a first leg and a second leg extend out of the first opening and a lever arm extends out of the second opening. In the retracted position, the lever arm has virtually no effect on the actuation of the engine valves, while in the extended position, the lever arm is positioned to contact the motion transmission component, thereby controlling the actuation of the engine valves. Furthermore, the first force, when applied to the lever arm by the motion transmission component, holds the lever arm in the extended position.

2. The system according to claim 1, further comprising: A biasing element configured to apply a biasing force to rotate the lever arm to the retracted position, wherein the first force applied by the motion transmission member is sufficient to overcome the biasing force applied by the biasing element.

3. The system of claim 1, wherein the second opening defines a first stop surface and a second stop surface, wherein the first stop surface is configured to define the retracted position and the second stop surface is configured to define the extended position.

4. The system of claim 3, wherein the second stop surface is configured to position the lever arm at a non-zero angle relative to the direction of application of the first force.

5. The system of claim 3, wherein the lever arm further includes a rotating cup disposed at the distal end of the lever arm, wherein the rotating cup is configured to contact the first stop surface when the lever arm is in the retracted position and to contact the second stop surface when the lever arm is in the extended position.

6. The system of claim 1, wherein the first force is a closing force applied by an engine valve spring to the engine valve and thereby to the motion transmission member.

7. The system according to claim 1, further comprising: A linear actuator having an active state and a non-active state; A sliding rack, which is slidably mounted on a fixed housing and operably connected to the linear actuator; and A biasing element configured to bias the sliding rack to a starting position when the linear actuator is in the non-activated state. When the linear actuator is in the activated state, the sliding rack overcomes the bias of the biasing element and moves to the fully displaced position. And the first leg and the second leg of the torsion spring are configured to intersect with a slot formed in the sliding rack, wherein: In the initial position, and when the first force is not applied to the lever arm by the motion transmission component, the slot engages the first leg of the torsion spring and positions the lever arm in the retracted position. In the initial position and when the first force is applied to the lever arm by the motion transmission member, the slot in the first leg of the torsion spring induces a load to position the lever arm in the retracted position when the first force is removed from the lever arm. In the fully displaced position and when the first force is not applied to the lever arm by the motion transmission component, the slot engages the second leg of the torsion spring and positions the lever arm in the extended position. In the fully displaced position and when the first force is applied to the lever arm by the motion transmission member, the slot in the second leg of the torsion spring causes a load to position the lever arm in the extended position when the first force is removed from the lever arm.

8. The system of claim 7, wherein the biasing element is a spring disposed between the linear actuator and the sliding rack.

9. The system of claim 7, wherein the slot in the sliding rack is an H-shaped slot having a first longitudinal channel and a second longitudinal channel, wherein the first leg of the torsion spring intersects the first longitudinal channel and the second leg of the torsion spring intersects the second longitudinal channel.

10. The system of claim 1, wherein the movement of the housing relative to the motion transmission component is fixed.

11. The system of claim 1, wherein the housing is provided by another motion transmission component of the at least one motion transmission component.

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