Valve bridge system for resisting uncontrolled movement of valve bridge

Abstract

A valve bridge system includes a valve bridge body configured to extend between at least two engine valves of an internal combustion engine. The valve bridge body includes a through hole configured to align with a first engine valve and receive a bridge pin. The bridge pin boss has a through hole formed therein, has a longitudinal length, and terminates at an upper surface. The longitudinal length is configured such that when the valve bridge is in an uncontrolled state relative to the at least two engine valves, the upper surface of the bridge pin boss contacts a surface of a secondary rocker arm to resist uncontrolled movement of the valve bridge.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to valve actuation systems in internal combustion engines, and in particular to valve bridge systems including valve bridge guides for use in connection with such valve actuation systems. BACKGROUND

[0002] Valve actuation systems for internal combustion engines are known in the art. Such valve actuation systems generally include a valve train, which in turn includes one or more components that transmit valve actuation motion from a valve actuation motion source (e.g., one or more cams) to engine valves. A component commonly found in valve trains is a so-called valve bridge, which includes a device that spans two or more engine valves associated with a given cylinder. In many cases, such valve bridges allow another component of the valve train (e.g., a rocker arm) to simultaneously actuate the other two engine valves with which the valve bridge is engaged. Ideally, in operation, the counteraction of the force exerted by the motion transmitting component (e.g., a rocker arm) and by the engine valve spring ensures that the valve bridge remains in simultaneous contact with the motion transmitting component and the engine valve (allowing for normal lash settings). In this way, the valve bridge is always aligned and positioned with the engine valve to transmit valve actuation motion to the engine valve. As used herein, this state of the valve bridge relative to the engine valve is referred to as the “controlled state” of the valve bridge.

[0003] Some valve actuation systems are configured to provide so-called auxiliary valve actuation motion, i.e., valve actuation motion in addition to that used to operate the engine in positive power production mode by combustion of fuel. In such valve actuation systems, the valve bridge can be configured to include a device or lost motion assembly that allows valve actuation motion to be transmitted by the valve bridge to the engine valve, or selectively “lost” in the event that such motion is not transmitted by the valve bridge to the engine valve. Figure 1Such a system is shown in U.S. Patent Application Publication No. 2012 / 0024260, the teachings of which are incorporated herein by reference. In this case, the valve bridge 710 is provided with a lost motion assembly in the form of a locking mechanism. In the illustrated embodiment, the locking mechanism includes a ball 740 that can be forced through an opening in the outer plunger 720 and into engagement with a notch 770 formed in the body of the valve bridge. In this state, the ball 740 is prevented from disengaging from the notch 770 due to the outer diameter of the inner plunger 760, thereby locking the outer plunger 720 in fixed relation to the valve bridge 710. Thus, any valve actuation motion applied to the outer plunger 720 by the rocker arm 200 / 400 is transmitted to the valve bridge 710 and the engine valves 810 / 910, 820 / 920. However, when a recess formed in the inner plunger 760 is aligned with the ball 740, the ball can disengage from the recess 770 in the valve bridge 710, thereby unlocking the outer plunger 720 and allowing it to reciprocate relative to the valve bridge 710. In this state, any valve actuation motion applied to the outer plunger 720 causes the outer plunger to move within the valve bridge 710 and is not transmitted to the engine valves. Another valve bridge-based locking / unlocking system is disclosed in U.S. Patent Application Publication No. 2014 / 0326212, the teachings of which are incorporated herein by reference.

[0004] However, in Figure 1 In systems of the type shown, there is a possibility of partial engagement of the locking mechanism. In this case, valve actuation motion can be initially applied to the engine valves, thereby lifting the engine valves off their valve seats. However, due to the partial engagement of the locking mechanism, increased loading or vibration in the valve actuation system causes the locking mechanism to rapidly switch from the partially locked state to the unlocked state. When this occurs, the force provided by the valve actuation motion to open the engine valves is suddenly eliminated, allowing the engine valves to rapidly accelerate in an uncontrolled manner to the closed position under the considerable force of the valve springs. When the engine valves reach the fully closed position (i.e., stop on the valve seats formed in the cylinder head), the momentum applied to the valve bridge can cause the valve bridge to continue on an uncontrolled trajectory in a generally direction away from the engine valves until it strikes a rocker arm or some other object. In fact, it is possible for the valve bridge to come off either end of the engine valves such that the valve bridge moves away from the engine valves, thereby causing engine damage. This type of movement is referred to as "uncontrolled movement" of the valve bridge, and as used herein, this condition of the valve bridge relative to the engine valves is referred to as the "uncontrolled state" of the valve bridge. The uncontrolled state of the valve bridge is also known to occur as a result of overspeed operation of the internal combustion engine.

[0005] In view of this possibility of failure, a solution to prevent, minimize, or accommodate the uncontrolled state of the valve bridge, regardless of the cause, would represent a welcome addition to the art. SUMMARY

[0006] The present disclosure describes a valve bridge system that overcomes the above-mentioned problems of prior art valve bridge systems. In a first main embodiment, a valve bridge system includes a valve bridge configured to extend between at least two engine valves of an internal combustion engine. A valve bridge guide is operably connected to the valve bridge and includes a valve bridge control surface for selectively contacting the valve bridge or at least one of an engine valve assembly including the at least two engine valves, at least two valve springs corresponding to the at least two engine valves, and at least two spring retainers corresponding to the at least two engine valves. In this embodiment, the valve bridge guide can be made of a moldable polymer. The valve bridge control surface is configured to avoid contact with the valve bridge or the engine valve assembly when the valve bridge is in a controlled state relative to the at least two engine valves, and is further configured to contact the valve bridge or the engine valve assembly to resist uncontrolled movement of the valve bridge when the valve bridge is in an uncontrolled state relative to the at least two engine valves. In embodiments, the valve bridge guide is configured to extend between the at least two valve springs, where the valve bridge control surface is at least one concave surface corresponding to at least one convex surface defined by the at least two valve springs or the at least two spring retainers, or is a convex surface defined by a portion of the valve bridge. More specifically, each of the at least one concave surface can be bounded by opposing edges such that a line intersecting the opposing edges forms a secant relative to an outer diameter of a corresponding one of the at least two valve springs or the at least two spring retainers.

[0007] The valve bridge guide and the valve bridge can form a unitary structure, or the valve bridge guide can include one or more separate components operably connected to the valve bridge. In embodiments, the valve bridge guide includes two guide members configured to engage opposite sides of the valve bridge, and can further include at least one fastener for operably coupling the two guide members together. The valve bridge guide can include an opening for receiving at least a portion of the valve bridge, and can further include at least two protruding members, each of which protrudes from the valve bridge guide toward the valve bridge and extends at least past a lower surface of the valve bridge facing the at least two engine valves. Further, the at least two protruding members can define the valve bridge control surface. Alternatively, each of the at least two protruding members can include an attachment surface for engaging a corresponding surface of the valve bridge.

[0008] In a second main embodiment, a valve bridge system can include a valve bridge configured to extend between at least two engine valves of an internal combustion engine, the valve bridge including a lower surface facing the at least two engine valves and an upper surface opposite the lower surface. The system of this main embodiment further includes a valve bridge guide having a first member held in a first fixed position relative to the valve bridge, the first member including a first surface facing and at a predetermined distance from the upper surface of the valve bridge when the at least two engine valves are in a closed state. The predetermined distance is configured to prevent contact between the first surface and the upper surface of the valve bridge when the upper bridge body is in a controlled state relative to the at least two engine valves, and to allow contact between the first surface and the upper surface of the valve bridge to resist uncontrolled movement of the valve bridge when the valve bridge is in an uncontrolled state relative to the at least two engine valves. In cases where the valve bridge includes a receptacle receiving an engine valve tip of one of the at least two engine valves, the predetermined distance can be less than a depth of the receptacle.

[0009] The first fixed position of the first member can be aligned with a first engine valve of the at least two engine valves that is farthest from a rocker shaft of the internal combustion engine. The valve bridge system can further include a second member held in a second fixed position relative to the valve bridge, the second member including a second surface facing and at the predetermined distance from the upper surface of the valve bridge. In this case, the second fixed position of the second member is aligned with a second engine valve of the at least two engine valves that is closest to the rocker shaft of the internal combustion engine. The first member can be configured to be attached to a cylinder head of the internal combustion engine, while the second member can form an integral structure with a rocker shaft pedestal of the internal combustion engine.

[0010] In a further alternative of this second main embodiment, the valve bridge guide can further include a bridge pin disposed in one end of the valve bridge and aligned with an engine valve of the at least two engine valves. Alternatively, the first member of the valve bridge guide in this embodiment can include an arch configured for attachment to the cylinder head, extending between the at least two engine valves and above the upper surface of the valve bridge, the arch further including an opening formed therein aligned with a portion of the contact engine mechanism assembly of the valve bridge. BRIEF DESCRIPTION OF DRAWINGS

[0011] The features described in this disclosure are particularly pointed out and distinctly claimed in the accompanying claims. These features and the accompanying advantages will become more fully apparent to those of ordinary skill in the art by

[0012] Figure 1 is a sectional view of a valve actuation system comprising a valve bridge with a locking mechanism according to the prior art;

[0013] Figure 2 and Figure 3 are respective top and bottom isometric sectional views of a first main embodiment of a valve actuation system containing a valve bridge and a valve bridge guide according to the present disclosure;

[0014] Figure 4 is a schematic diagram showing the relationship between a valve spring and the surface of a valve bridge guide according to the first main embodiment;

[0015] Figure 5 and Figure 6 are respective isometric and sectional views (along sectional plane VI-VI) of a valve bridge and a valve bridge guide according to a first variant of the first main embodiment;

[0016] Figure 7 and Figure 8 are respective isometric and sectional views (along sectional plane VIII-VIII) of a valve bridge and a valve bridge guide according to a second variant of the first main embodiment;

[0017] Figure 9 and Figure 10 are respective isometric and sectional views (along sectional plane X-X) of a valve bridge and a valve bridge guide according to a third variant of the first main embodiment;

[0018] Figure 11 is an isometric view of a valve bridge guide according to a fourth variant of the first main embodiment;

[0019] Figure 12 is an isometric view of a valve bridge and a valve bridge guide according to a fifth variant of the first main embodiment;

[0020] Figure 13 is an isometric view of a valve bridge guide according to a sixth variant of the first main embodiment;

[0021] Figure 14 and Figure 15 are respective isometric and sectional views of a valve bridge guide according to a seventh variant of the first main embodiment;

[0022] Figure 16is an isometric view of a valve bridge guide according to an eighth variant of the first main embodiment;

[0023] Figure 17 is an isometric view of a valve bridge guide according to a ninth variant of the first main embodiment;

[0024] Figures 18 to 21 are respective isometric, side and front views of a valve bridge and valve bridge guide according to a second main embodiment;

[0025] Figure 22 is a top isometric view of a valve bridge and valve bridge guide according to a first variant of the second main embodiment;

[0026] Figure 23 is a sectional view of a valve bridge according to the prior art;

[0027] Figure 24 is a sectional view of a valve bridge according to a third main embodiment;

[0028] Figure 25 are sectional views of valve bridges according to fourth to sixth main embodiments;

[0029] Figures 26 to 28 are respective top isometric and sectional views of a valve bridge according to a seventh main embodiment;

[0030] Figure 29 is a side view of a valve bridge according to an eighth main embodiment;

[0031] Figure 30 and Figure 31 are respective isometric and sectional views of a valve bridge and bridge pin according to a ninth main embodiment;

[0032] Figure 32 is a side partial sectional view of a valve actuation system according to the prior art;

[0033] Figure 33 is a top isometric view of a valve actuation system according to a tenth embodiment;

[0034] Figure 34 and Figure 35 are respective top and bottom isometric views of a valve bridge and valve bridge guide according to an eleventh embodiment; and

[0035] Figure 36 is a top isometric view of a valve bridge and valve bridge guide of Figure 34 and Figure 35 deployed in a valve actuation system. DETAILED DESCRIPTION

[0036] Figures 2 to 36Various embodiments of a valve bridge system including valve bridge guides according to this disclosure are shown. Figures 2 to 36 In all the embodiments and variations shown, it is assumed that the valve bridge is Figure 1 The type shown, namely, the valve bridge has Figure 1 The locking mechanisms shown and described above are of the general type.

[0037] Figure 2 A first embodiment according to this disclosure is shown, wherein an internal combustion engine 202 includes a pair of valve bridges 204, 212 for a single cylinder. In the illustrated embodiment, each valve bridge 204, 212 actuates two corresponding engine valves, but it is possible for each valve bridge to actuate more than two engine valves. As is known in the art, each valve bridge 204, 212 (or any other valve bridge shown and described herein) can actuate two engine valves of the same type, i.e., two intake valves or two exhaust valves. For ease of illustration, only the features and operation of the first valve actuation system according to the first embodiment are described; it should be understood that the described features and operation are equally applicable to all valve bridges included in an internal combustion engine.

[0038] Therefore, as shown in the figure, the first valve bridge 204 spans a pair of engine valves in a manner known in the art. Figure 2 (Not visible in the image). Each engine valve has valve springs 208, 210 and valve spring retainers 209, 211, the valve springs biasing their corresponding engine valves to a closed state (i.e., the engine valve head engaging with a valve seat formed in the cylinder head 230), and the valve spring retainers attached to the valve stems of the engine valves. As further shown, the valve bridge system 202 further includes a valve bridge guide 206 extending downward from the valve bridge 204 (i.e., in the direction of the cylinder head and away from the rocker arm 220) and extending between the valve springs 208, 210. In an embodiment, the distance by which the valve bridge guide 206 extends between the valve springs 208, 210 is minimized by a portion of the surrounding locking mechanism of the valve bridge 204 (e.g., see...). Figure 1 The depth of the portion of the valve bridge that accommodates the outer plunger 720 and the outer plunger spring 746 is specified. Figure 2 In the illustrated embodiment, the valve bridge and valve bridge guide form an integral structure, i.e., the integral portion is not separated, such that the locking mechanism is accommodated in the openings formed in the valve bridge 204 and valve bridge guide 206 (in Figure 3 (Best shown in the image). As described in more detail below, the valve bridge guide 206 includes at least one valve bridge control surface configured to interact with one or both of the valve springs 208, 210 or valve spring retainers 209, 211 to prevent, minimize or at least accommodate uncontrolled movement of the valve bridge 204.

[0039] Figure 3 It shows the section line III-III (as shown) Figure 2 The image shows a cross-sectional view of the valve bridge guide 206 and the first valve spring 208. An opening 310 for accommodating the locking mechanism is formed in the valve spring guide 206, and... Figure 3 The valve stem 320, which is disposed within the corresponding valve spring 208, is further shown. More specifically, Figure 3 Two valve bridge control surfaces 402 defined by valve bridge guide 206 are shown, such that the valve bridge control surfaces 402 conform to the corresponding valve springs 208, 210. Figure 3 (Only one is shown in the diagram), namely, the valve bridge control surface 402 is a concave surface relative to the convex outer surface of the valve springs 208, 210. Although conforming, the valve bridge control surface 402 is configured such that during the controlled state of the valve bridge, the valve bridge control surface 402 (and therefore the valve bridge guide 206) can avoid contact with its corresponding valve springs 208, 210. The valve bridge control surface 402 can be configured as close as possible to the valve springs 208, 210 (within manufacturing tolerances) such that normal movement and vibration of the valve bridge 204, valve bridge guide 206, and valve springs 208, 210 are insufficient to cause contact between the valve bridge control surface 402 and the valve springs 208, 210. For example, as is known in the art, when, for example, the compression spring of valve springs 208, 210 deforms (i.e., is compressed), the outer diameter of the spring will increase slightly. Therefore, the valve bridge control surface 402 can be configured to take into account the maximum expected variation in the spring diameter while remaining as close as possible to the valve springs 208, 210.

[0040] In some cases, it can be undesirable for the valve bridge guide 206 to contact the valve springs 208, 210, as this can lead to early degradation of the valve springs 208, 210. Thus, it can be desirable to instead configure the valve bridge control surface 402 to contact the spring retainers 209, 211. To achieve this configuration, it can be necessary to size the spring retainers 209, 211 to have an outer diameter that is larger than the outer diameter of the valve springs 208, 210. In this case, the valve bridge control surface 402 is instead defined by the valve bridge guide 206, such that the valve bridge control surface 402 conforms to the corresponding spring retainer 209, 211, i.e. the valve bridge control surface 402 is a concave surface relative to the convex outer surface of the spring retainers 209, 211. Again, such a concave surface is configured such that, during the controlled state of the valve bridge, the valve bridge control surface 402 is able to avoid contact with its corresponding spring retainer 209, 211, and is further configured to be as close as possible to the valve springs 208, 210 (within manufacturing tolerances), such that normal movement and vibration of the valve bridge 204, valve bridge guide 206, and valve springs 208, 210 are not sufficient to cause contact between the valve bridge control surface 402 and the spring retainers 209, 211.

[0041] While the various figures shown and described in the present disclosure show at least two concave valve bridge control surfaces 402, this is not a necessary requirement. For example, a single such valve bridge control surface 402 can be employed if used in conjunction with another feature that provides additional control over the uncontrolled movement of the valve bridge 204. For example, in the case where the valve bridge 204 is equipped with a bridge pin (see, e.g., the element 2102 of Figure 21 a single valve bridge control surface 402 and bridge pin can be sufficient.

[0042] With respect to Figure 4 Further description of the configuration of the valve bridge control surface 402 according to the preferred embodiment, Figure 4 A valve bridge guide 206 and valve spring 208 are shown schematically in exaggerated form. (Alternatively, as described above, Figure 4The valve springs 208 shown can be considered as spring retainers, but for ease of description, only the valve springs 208 are described herein. As shown, the valve bridge guide 206 includes a concave valve bridge control surface 402 proximate the outer periphery 408 of the valve springs 208. In practice, the gap between the valve bridge control surface 402 and the outer periphery 408 is based in part on the manufacturing tolerances of the valve springs 208, 210 (or spring retainers 209, 211) and the valve bridge 204. Additionally, the gap is based on the gap of the engine valve end within the receptacle formed in the valve bridge 204 for receiving the engine valve end. For example, if the valve bridge 204 is allowed to move ±0.25 mm, the gap between the valve spring 208 and the valve bridge control surface 402 should be greater than the tolerance of the parts plus the 0.25 mm of play allowed. Furthermore, the chamfer at the bottom of the valve bridge 204 should be large enough so that if the valve bridge 204 experiences uncontrolled movement over the entire gap of the valve spring or spring retainer, the valve bridge 204 can still reposition itself over the engine valve end.

[0043] As Figure 4 As further shown, the circumferential length of the concave valve bridge control surface 402 (relative to the outer periphery 408 of the spring 208) is bounded by opposing edges 404, 406. In this preferred embodiment, the opposing edges 404, 406 are spaced a degree such that when the valve bridge guide 206 is positioned during the controlled state of the valve bridge 204, a line 410 intersecting the opposing edges 404, 406 as shown forms at least a secant relative to the outer periphery 408 of the valve spring 208. Configured in this manner, it should be appreciated that movement of the valve bridge guide 206 in either direction indicated by the line 410 (as can occur during the uncontrolled state of the valve bridge 204) will result in contact between the concave valve bridge control surface 402 and the spring outer periphery 408 if sufficiently large, such that the valve bridge guide 206 will be deflected generally in a direction away from the valve spring 208 and toward the other valve spring 210. More generally stated, any rotational movement of the valve bridge 204 about the axis of the lock mechanism centerline is also limited to lateral movement in two horizontal planes. In light of this, and referring back to Figure 2 And Figure 3 During the uncontrolled state of the valve bridge 204, this operation of the concave valve bridge control surface 402 will tend to realign the valve bridge guide 206 itself with the valve springs 208, 210, effectively dampening or even eliminating any uncontrolled movement of the valve bridge 204 and the valve bridge guide 206.

[0044] Referring now to Figure 5 And Figure 6A first variant of the valve bridge guide 502 comprises an integral part separate from the valve bridge 204, having a valve bridge control surface 402 formed on its lateral side, as shown. The valve bridge 204 is also shown as having a receiving portion 614 for receiving the valve stem end of an engine valve, as known in the art and as described above. In this embodiment (and Figures 7 to 13 In another embodiment shown, the valve bridge guide 502 may be made of the same material as the valve bridge 204 (e.g., steel); however, in a preferred embodiment, the valve bridge guide 502 is formed of a lighter, stronger material that is still softer than the valve bridge springs 208, 201 (or spring retainers 209, 211) to avoid breakage or damage. Suitable moldable polymers known in the art, for example, can be used for this purpose. Other types of materials for manufacturing the valve bridge guide will be apparent to those skilled in the art.

[0045] In any case, as further shown, the valve bridge guide 502 has an opening or hole 602 formed therein, which is configured to receive a portion 604 of the valve bridge 204 in a close fit. As shown, the portion 604 of the valve bridge 204 received by the valve bridge guide 502 preferably accommodates at least some locking mechanisms 606. As further shown, in this embodiment, both the valve bridge guide 502 and the portion 604 of the valve bridge 204 include fastener receiving features 504, 608. In this embodiment, the fastener receiving feature 504 of the valve bridge guide includes a hole intersecting with the opening 602 formed in the valve bridge guide 502. Thus, where the hole intersects with the opening 602, the fastener receiving feature 504 essentially comprises a channel with a semi-circular cross-section formed in the sidewall of the opening 602. Complementarily, the fastener receiving feature 608 of the portion 604 of the valve bridge 204 is also formed as a semi-circular channel in the outer sidewall surface of the portion 604. When aligned, these corresponding fastener receiving features 504, 608 can receive fasteners 610, 612, allowing valve bridge guide 502 to be operably connected to portion 604 of valve bridge 204. For example, in the illustrated embodiment, fastener 612 may comprise a split locating pin as shown, but those skilled in the art will recognize that other types of fasteners, such as screws, can be used equivalently. In this way, valve bridge guide 502 is relatively rigidly attached to valve bridge 204, allowing them to move uniformly. As an alternative to the above-described fastener embodiment, valve bridge guide 502 (or Figures 7 to 13 Other embodiments of the valve bridge guide shown can alternatively be securely attached to the valve bridge 204 using a suitable, strong, and durable epoxy resin or similar adhesive. Furthermore, combinations of these technologies can also be considered as design choices.

[0046] See now Figure 7and Figure 8 The second variation of the valve bridge guide 702 is substantially similar to the valve bridge 502 of Figure 5 and Figure 6 the valve bridge 204 in that it comprises a unitary body having a valve bridge control surface 402 formed on a lateral side thereof, as shown. However, in this embodiment, the valve bridge guide 702 comprises one or more teeth 802 extending inwardly from the side wall surface of the opening 602 and is configured to engage with a notch 804 formed in the outer side wall surface of the portion 604 of the valve bridge 204. For example, the notch 804 can comprise an annular groove or channel formed in the side wall of the portion 604 of the valve bridge 204. When the teeth 802 engage the notch 804, the valve bridge guide 702 is again operably connected to the valve bridge in a relatively rigid manner such that the valve bridge guide 702 and the valve bridge 204 move in unison. It should be noted that the arrangement of the one or more teeth 802 and the notch 804 can be equally reversed in this embodiment, i.e., the teeth 802 can be formed on the outer side wall surface of the portion 604 of the valve bridge 204 and the notch 804 is formed on the inner side wall surface of the opening 602.

[0047] As further shown in Figure 7 , the valve bridge guide 702 can comprise at least two protruding members 704, 706 protruding from the valve bridge guide 702 toward the valve bridge 204. As shown in Figure 8 , the valve bridge 204 has a lower surface 806 and, in an embodiment, the protruding members 704, 706 extend at least beyond the lower surface 806 of the valve bridge 204. In this embodiment, the at least two protruding members 704, 706 facilitate the orientation of the valve bridge guide 702 on the valve bridge 204, thereby preventing the valve bridge 204 from rotating relative to the valve bridge guide 702. In this manner, the at least two protruding members 704, 706 further facilitate the alignment of the valve bridge control surface 402 with the valve springs 208, 210 or the spring retainers 209, 211.

[0048] Referring now to Figure 9 and Figure 10, a third variation of the valve bridge guide 902 is shown, where the valve bridge guide 902 is again formed as a unitary body separate from the valve bridge 204, with the valve bridge control surfaces 402 formed on its lateral sides, as shown. However, in this embodiment, the valve bridge guide 902 has side openings 904 with cantilever latches or clips 906 disposed therein. As shown, the clips 906 are configured to engage corresponding notches 1002 formed in the outer sidewall surfaces of the portion 604 of the valve bridge 204. For example, the notches 1002 can again comprise annular grooves or channels formed in the sidewalls of the portion 604 of the valve bridge 204. When the clips 906 engage the notches 1002, the valve bridge guide 902 is again operably connected to the valve bridge 204 in a relatively rigid manner, such that the valve bridge guide 902 and the valve bridge 204 move in unison. As shown, the valve bridge guide 902 can further comprise secondary latch surfaces 908 configured to engage corresponding secondary notches 1004 formed in the portion 604 of the valve bridge 204. By providing multiple latch pairs 906, 1002 / 908, 1004, the stability of the valve bridge guide 902 relative to the valve bridge 204 can be improved.

[0049] Referring now to Figure 11 , a fourth variation of the valve bridge guide 1102 is shown. In this variation, the valve bridge guide 1102 is a unitary body disposed between the spring retainers 209, 211 and the valve bridge 204. Notches 1104, 1106 are provided to allow the valve bridge guide 1102 to be positioned relative to the ends of the engine valves. Additionally, a central opening 1107 can be provided that allows a portion of the valve bridge 204 (e.g., the portion that houses the locking mechanism as shown in Figure 1 , for example) to extend through the valve bridge guide 1102. Similar to the embodiments of Figure 7 and Figure 8 , the valve bridge guide 1102 includes at least two protruding members in the form of sidewalls 1108, 1110 that define a channel 1107 that, in turn, is configured to receive the valve bridge 204. In this embodiment, the inner surfaces 1112, 1114 of the sidewalls 1108, 1110 that rise above the valve bridge 204 act as valve bridge control surfaces that prevent lateral movement or rotation of the valve bridge 204 that can result during uncontrolled states of the valve bridge 204. Furthermore, although Figure 11Not shown, but additional valve bridge control surfaces 402 can optionally be provided on the lower portion 1118 of the valve bridge guide 1102 in order to prevent tilting of the valve bridge 204, as described above. To the extent that the valve bridge guide 1102 is securely attached to the valve bridge 204 (using any of the techniques described above), any excessive lifting of the valve bridge 204 (e.g., away from the engine valve tip) will cause a similar lifting in the valve bridge guide 1102, which again resists uncontrolled movement and allows the valve bridge 204 to again stabilize back onto the engine valve tip.

[0050] Referring now to Figure 12 , a fifth variation of a valve bridge guide 1202 is substantially similar to the valve bridge 502 of Figure 5 and Figure 6 in that it comprises a unitary body separate from the valve bridge 204, the body having valve bridge control surfaces 402 formed on lateral sides thereof, as shown. As further shown, and similar to the second variation shown in Figure 7 and Figure 8 , this embodiment of the valve bridge guide 1202 further comprises a plurality of protruding members 1204-1212 extending upwardly from the main body of the valve bridge guide 1202, the protruding members serving a similar purpose as described above. Additionally, as shown, each of the protruding members 1204-1212 comprises an attachment surface 1214, 1216 in the form of an inwardly extending finger 1214, 1216 provided at a terminal end of the protruding members 1204-1212 (only two of which are shown in Figure 12 ). The attachment surfaces so defined are configured to engage a corresponding surface 1220 of the valve bridge 204, in this case the upper surface of the valve bridge 204. In this manner, the valve bridge guide 1202 is retained on the valve bridge 204. Alternatively, and similar to the embodiments of Figure 9 and Figure 10 , the fingers 1214, 1216 can instead engage notches or similar features formed in the lateral sides of the valve bridge 204.

[0051] Figure 13A sixth variation of the first embodiment is shown, in which the valve bridge guide 1302 is formed from two guide members 1304, 1306 configured to engage opposite sides of the valve bridge. As in other embodiments, each of the guide members 1304, 1306 defines a valve bridge control surface 402 as described above. In addition, each of the guide members 1304, 1306 defines a first opening 1308 (only one shown) configured to receive a portion 604 (not shown) of the valve bridge 204. As further shown, each of the guide members 1304, 1306 also includes a channel or second opening 1310 configured to receive one of the arms of the valve bridge 204 (i.e., the portion of the valve bridge extending from the center of the valve bridge to one of the engine valves). In addition, one of the guide members 1304, 1306 includes complementary first latch 1312 and first latch recess 1314 and second latch 1316 and second latch recess 1318 form of fastener, such that the guide members 1304, 1306 can be securely connected to one another. Alternatively, any of the attachment mechanisms described above (dowel, epoxy, etc.) can be used as the “fastener” for this purpose. When connected, the guide members 1304, 1306 collectively define the valve bridge guide 1302, which remains in place relative to the valve bridge 204 due to the second openings 1310 encircling the arms of the valve bridge 204.

[0052] Figure 14 and Figure 15 A seventh variation of the first primary embodiment is shown, in which the valve bridge guide 1402 is formed as a stamped metal plate structure having a horizontal surface 1404 and a continuous sidewall 1406 extending downward therefrom. In this variation, similar to the embodiment shown in FIG. 6, the valve bridge guide 1402 is designed to rest on top of the spring retainers 209, 211 (not shown) and underneath the valve bridge 204 (not shown). In this embodiment, the sidewall 1406 is shown as extending past the initial portions of the spring retainers 209, 211 and the valve springs 208, 210. In embodiments, the extent of the sidewall 1406 is such that the valve bridge guide 1402 cannot be lifted completely away from the spring retainers 209, 211, despite any vertical displacement imparted to the valve bridge 204. In addition to a central opening 1418 that allows a portion of the valve bridge 204 to pass, the valve bridge guide 1402 contains a plurality of protruding members 1408-1416 (four shown in the example shown), which are similar to the protruding members 1208-1216 of the embodiment shown in FIG. 6. Figure 11 Figure 15 Figure 15 Figure 7 Figure 8 Figure 11 and Figure 12 ​​​​​those shown in FIGS. 1 1 and 12. As shown, the protruding members 1408-1416 are formed as upwardly curved portions of the horizontal surface 1404, which results in openings 1426, 1428 that allow passage of the ends of the engine valves 1502. In this case, the protruding members 1408-1416 again define valve bridge control surfaces 1422, 1424 for resisting uncontrolled movement of the valve bridge 204.

[0053] Figure 16 An isometric view showing an eighth variation of the first primary embodiment is shown, in which the valve bridge guide 1602 comprises two guide members 1603 (only one shown) configured to engage opposite sides of the valve bridge 204 (not shown). Each guide member 1603 is formed as a stamped metal plate structure having a horizontal surface 1604 and a continuous sidewall 1606 extending downwardly therefrom, similar to the embodiments of Figure 14 and Figure 15 , but configured to rest atop only a single spring retainer 209. Again, each guide member 1603 comprises a plurality of upwardly extending protruding members 1608, 1610 and a central opening 1612 for passage of the ends of the engine valves, in which each of the protruding members 1608, 1610 defines a valve bridge control surface 1614 for resisting uncontrolled movement of the valve bridge 204.

[0054] Similar to the embodiments of Figure 16 , Figure 17 the embodiment shown comprises a valve bridge guide 1702 comprising a pair of guide members 1703 configured to rest atop separate spring retainers 209, 211. In this case, formed from moldable polymer, each guide member 1703 comprises a horizontal surface 1704 and a continuous sidewall 1706 extending downwardly therefrom, similar to the embodiments of Figure 14 and Figure 15 , but configured to rest atop only a single spring retainer 209, as in the embodiments of Figure 16 . Again, each guide member 1703 comprises a plurality of upwardly extending protruding members 1708, 1710 and a central opening 1712 for passage of the ends of the engine valves, in which each of the protruding members 1708, 1710 defines a valve bridge control surface 1714 for resisting uncontrolled movement of the valve bridge 204. In this case, however, each guide member 1703 is also provided with a laterally concave valve bridge control surface 402 as described above. In this case, however, the laterally concave valve bridge control surface 402 is not configured to conform to the outer surface of the valve springs 208, 210, but rather to the portion of the valve bridge 204 extending downwardly between the valve springs 208, 210 and housing the locking mechanism, in unison as described and shown above with respect to Figure 1 .

[0055] Referring now to Figures 18 to 21 , a second primary embodiment in accordance with the present disclosure is shown, in which the internal combustion engine 202 contains a pair of valve bridges 204, 212 for a single cylinder. In the illustrated embodiment, each valve bridge 204, 212 actuates two corresponding engine valves, although each valve bridge can again actuate more than two engine valves. In the illustrated embodiment, the first valve bridge 204 spans a pair of engine valves in a conventional manner known in the art. Each engine valve has a valve spring 208, 210 biasing its corresponding engine valve to a closed state, and a valve spring retainer 209, 211 attached to the valve stem of the engine valve. As is conventional, the valve spring retainer 209, 211 is configured to retain the valve spring 208, 210 in place on the valve stem. As is conventional, the valve bridge 204 is configured to actuate the engine valves in a conventional manner. Figure 19 Best shown, the valve bridge 204 contains a lower surface 1902 facing the engine valves and an upper surface 1904 opposite the lower surface 1902.

[0056] As further shown in this second primary embodiment, the valve bridge system further contains a valve bridge guide in the form of a first member 1802 having a first surface 1906 facing the upper surface 1904 of the valve bridge 204. Using suitable fasteners 1806 (such as bolts threaded into the cylinder head or similar securing structure), the first member 1802 is held in a first fixed position relative to the valve bridge 204. In particular, the first fixed position holds the first member 1802 at a predetermined distance 1908 from the upper surface 1904 of the valve bridge 204 when the at least two valve bridges 204, 212 are held in a closed state. Additionally, as shown, the first fixed position of the first member 1802 is aligned with a first engine valve of the at least two engine valves, where the first engine valve is furthest from the rocker shaft 1808 of the internal combustion engine 202. As shown, the first member 1802 can be configured such that it is aligned with the first engine valve for more than one valve bridge 204, 212 as described. Moreover, the first member 1802 can also extend across valve bridges 204, 212 for multiple cylinders of the internal combustion engine in this manner, or can contain multiple such first members 1802, where the configuration of the cylinders prevents the use of a single first member 1802.

[0057] In this embodiment, the predetermined distance 1908 between the first member 1802 and the upper surface 1904 of the valve bridge 204 is preferably sufficient to prevent contact between the first surface 1906 of the first member 1802 and the upper surface 1904 of the valve bridge 204 when the valve bridge 204 is in a controlled state relative to at least two engine valves, and sufficient to allow contact between the first surface 1906 and the upper surface 1904 when the valve bridge 204 is in an uncontrolled state relative to at least two engine valves, in order to resist uncontrolled movement of the valve bridge 204. As used herein, uncontrolled movement of the valve bridge 204 is resisted to such an extent that, when operated in a controlled state, any of the disclosed valve bridge guides resists movement of the valve bridge 204 outside its normal range of movement. Therefore, although Figures 2 to 12 The various variations of the first embodiment shown in the diagram cause tilting or rotational movement of the valve bridge 204 relative to the engine valve, but the first member 1802 counteracts excessive vertical displacement of the valve bridge 204 relative to the engine valve, particularly preventing complete disengagement of the valve bridge 204 from the engine valve. Contact between the valve bridge 204 and the first member 1802 is avoided during controlled operation of the valve bridge 204 by defining a predetermined distance 1908 relative to the closed position of the engine valve. However, by further defining the predetermined distance 1908 to be sufficiently small, desired resistance to uncontrolled movement of the valve bridge 204 can be provided. In one embodiment, the predetermined distance 1908 may be based on the depth 2002 of the receiving portion 2004 provided by the valve bridges 204, 212 to engage the valve tip 2006 of the engine valve. Figure 20 Specifically, the predetermined distance 1908 can be selected to be less than the depth 2002 of the receiving portion 2004. In this way, if the valve bridges 204 and 212 operate in an uncontrolled state, they will contact the first member 1802 before they can travel a distance beyond the depth 2002 of the receiving portion 2004, which would otherwise cause the valve bridges 204 and 212 to disengage from the valve ends 2006. Furthermore, it is known that in some forms of engine brakes, only a single inner engine valve (i.e., the one closest to the rocker arm shaft) is actuated, which causes the portion of the valve bridge 204 that engages with the outer engine valve (i.e., the portion furthest from the rocker arm shaft) to rise slightly, for example, by about 1 mm to 2 mm. Therefore, the predetermined distance 1908 should be selected to accommodate the possibility of avoiding undesirable contact with the valve bridge 204. In addition, normal wear of the engine valve seats may cause the engine valve ends 2006 to rise over time, and the predetermined distance 1908 should also take this possibility into account.

[0058] In this second embodiment, the valve bridge guide can further include a second member 1804 held in a second fixed position relative to the valve bridge 204 and having a second surface 1910 facing the upper surface 1904 of the valve bridge 204. As with the first member 1802, the second surface 1910 is held at a predetermined distance 1908 from the upper surface 1904 for the same reasons described above. In embodiments, the second fixed position of the second member 1804 is aligned with a second of the at least two engine valves, where the second engine valve is closest to the rocker shaft 1808. Further, as best shown in FIGS. 18A and 18B, the second member 1804 can be formed as a unitary structure with the rocker base 1810. In this way, the first member 1802 and the second member 1804 can be aligned with different engine valves and at the same predetermined distance 1908 from the upper surface 1904, thereby functioning as a valve bridge guide to provide uniform resistance to uncontrolled movement. Figure 18 and Figure 19 In this way, the first member 1802 and the second member 1804 can be aligned with different engine valves and at the same predetermined distance 1908 from the upper surface 1904, thereby functioning as a valve bridge guide to provide uniform resistance to uncontrolled movement.

[0059] As is known in the art, some valve actuation systems include auxiliary motion sources and valve mechanisms that provide auxiliary motion to a single engine valve despite the presence of a valve bridge 212. This is accomplished through the use of a bridge pin 2102, as is known in the art, that allows auxiliary valve actuation motion to be applied to a single engine valve, and primary valve actuation motion to also be applied to the single engine valve via the valve bridge 212. In this case, the presence of the bridge pin 2102 through the valve bridge 212 effectively functions as the second member 1804 that defines the valve bridge guide. That is, if the valve bridge 212 is operated in an uncontrolled state, the presence of the bridge pin 2102 (operably connected to both the auxiliary rocker 2104 and the single engine valve) will operate to limit the valve bridge 212 to only sliding motion relative to the bridge pin 2102. In this case, the presence of the auxiliary rocker 2104 (or other auxiliary valve mechanism component) will operate to prevent the valve bridge 212 from moving away from the bridge pin 2102. Likewise, in the case where the first member 1802 is provided (as shown), the combined operation of the first member 1802 and the second member 1804 will resist uncontrolled movement of the valve bridge 212, particularly upward movement.

[0060] Figure 22 A first variation of the second embodiment is shown, where the valve bridge guide includes a first member 2202 formed as a three-sided arch or "band". Similar to the embodiment of FIGS. 18A and 18B, the first member 2202 is held in a fixed position relative to the valve bridge 204 and has a first surface 2210 facing the upper surface 1904 of the valve bridge 204. As with the first member 1802, the first surface 2210 is held at a predetermined distance 2208 from the upper surface 1904 for the same reasons described above. In embodiments, the fixed position of the first member 2202 is aligned with a first of the at least two engine valves, where the first engine valve is closest to the rocker shaft 1808. Further, as best shown in FIGS. 22A and 22B, the first member 2202 can be formed as a unitary structure with the rocker base 1810. In this way, the first member 2202 and the second member 1804 can be aligned with different engine valves and at the same predetermined distance 2208 from the upper surface 1904, thereby functioning as a valve bridge guide to provide uniform resistance to uncontrolled movement. Figures 18 to 21 and Figure 22The variant shown resists uncontrolled movement by positioning the first member 2202 in contact with the upper surface 1904 of the valve bridge 204. In this embodiment, the first member 2202 may comprise a metal plate or similar material having two generally vertical elongated sides 2204 extending from above the valve bridge 204 to the base of the engine valve springs 208, 210. Figure 22 (One is shown in the diagram), wherein each of the elongated sides 2204 is mounted to the cylinder head 230. At the highest normal rest point of the valve bridge 204 (i.e., when the engine valves are fully closed) and above the upper surface 1904 of the valve bridge 204, a substantially horizontal third side 2206 of the first member 2202 connects the first and second elongated sides 2204. Figures 18 to 21 As in the embodiment, the third side 2206 is preferably maintained at a predetermined distance 1908 from the upper surface 1904. Figure 22 In a fixed position (not shown in the image). As further shown, the third side 2206 includes an opening 2210 that allows a portion of the valve bridge 204 (see, for example, see...) to be in a fixed position. Figure 1 The outer plunger 720 / cap 730 contacts the rocker arm 2212, as shown. In this variant, the displacement of the valve bridge 204 is limited by the third side 2206 of the first member 2202 and the opening 2210 formed therein.

[0061] Figure 23 This is a cross-sectional view of a valve bridge illustrating the shortcomings of existing technology systems. Specifically, Figure 23 A valve bridge with a valve bridge body 2302 spanning two engine valve stems 2304 and 2306 is shown. As shown, the first engine valve 2306 is actuated by an auxiliary rocker arm 2312 via a bridge pin 2308 that receives the stem of the first engine valve 2306. Furthermore, the bridge pin 2308 is received in a through-hole 2310 formed in the valve bridge body 2302 and aligned with the first engine valve 2306, thereby allowing the bridge pin 2308 to contact the auxiliary rocker arm 2312. Additionally, the valve bridge body 2302 includes a receiving portion 2314 aligned with and configured to receive the stem of the second engine valve 2304. Figure 23 In the middle, valve bridge 2302 is in an uncontrolled state as depicted because the receiving part 2314 loses contact with the second engine valve 2304. This is due to the fact that no surface is provided to prevent valve bridge 2302 from moving upward during the uncontrolled state.

[0062] Figure 24 A valve bridge according to a third main embodiment is shown, wherein a valve bridge substantially similar to... Figure 23The valve bridge depicted in the image is a valve bridge. However, in this case, the valve bridge also includes a bridge pin boss 2402, which has a through hole 2404 formed therein, and... Figure 23 The embodiment shown has a greater longitudinal length (or height) compared to the previous one. Therefore, the upper surface 2406 of the valve bridge boss 2402 is closer to the lower surface 2408 of the auxiliary rocker arm 2312 (e.g., the lower surface of the actuator in the depicted embodiment). Therefore, when the valve bridge is in an uncontrolled state, causing upward movement of the valve bridge body 2302, the upper surface 2406 of the valve bridge boss 2402 will contact the lower surface 2408 of the auxiliary rocker arm 2312 before the valve bridge body 2302 has a chance to completely disengage from the valve stem. This is in... Figure 24 As shown, the contact between the upper surface 2406 and the lower surface 2408 prevents the receiving part 2410 from completely disengaging from the rod of the second engine valve 2304.

[0063] It should also be understood that a similar upper surface of the portion of the valve bridge body 2302 aligned with the main rocker arm 2412 can be configured in a manner similar to the upper surface 2406 of the bridge pin boss 2402. In this case, the height of the valve bridge body 2302 aligned with the main rocker arm 2412 can be similarly increased such that the upper surface 2411 of the valve bridge body 2302 may contact the main rocker arm 2412 (e.g., the lower surface of the rotating foot in the depicted embodiment) during uncontrolled movement of the valve bridge body 2302. However, in this case, the height of the upper surface 2411 must be chosen so as not to interfere with the ability of the collapse mechanism 2414 to fully absorb any valve actuation movement provided by the main rocker arm 2412. In other words, the upper surface 2411 should not be increased to the point of contact with the main rocker arm 2412 during the controlled state (or controlled movement) of the valve bridge body 2302 and when the collapse mechanism 2414 absorbs the main valve event.

[0064] See now Figure 25 The diagram shows the valve bridge according to the fourth to sixth main embodiments. Specifically, Figure 25 Similarly, it is shown that in the construction, something similar... Figure 23 The valve bridge shown is a valve bridge. The fourth main embodiment relates to the feature of the clearance between the inner diameter of the through-hole 2502 and the outer diameter of the bridge pin 2504. In particular, because the clearance between the through-hole and the bridge pin is strictly controlled and minimized, uncontrolled movement will cause the valve bridge body 2302 to "clamp" (or jam) with the bridge pin 2504. This is in Figure 25 The contact point 2505 between the through hole 2502 and the bridge pin 2504 is shown in the diagram. Furthermore, this clamping reduces any further travel of the valve bridge body 2302, thereby tending to keep the valve bridge body 2302 aligned with the engine valves.

[0065] Figure 25 A fifth principal embodiment is further illustrated, depicting an increased radius spring retainer 2506 (relative to the radius of a typical spring retainer 2510, i.e., comparable to the radius of a valve spring (not shown)). In this embodiment, the increased radius spring retainer 2506 allows the portion 2508 of the valve bridge body 2302 extending between the engine valve stems to contact the increased radius spring retainer 2506 more quickly at 2511 during uncontrolled movement (particularly rotation of the valve bridge body 2302), thereby resisting further rotation of the valve bridge body 2302.

[0066] also, Figure 25 A sixth main embodiment is further illustrated, showing an extended valve stem feature. In the illustrated embodiment, the extended valve stem feature takes the form of a bridge pin 2512 residing in the second through-hole 2518. As shown, the bridge pin 2512 moves freely up and down on the engine valve stem 2514. In this case, when the valve bridge body 2302 is in an uncontrolled state, the bridge pin 2512 moves freely upward with the valve bridge body 2302. As long as the bridge pin 2512 remains on the engine valve stem 2514, although the bridge pin 2512 and the valve bridge body 2302 move uncontrolled, the bridge pin 2512 keeps the valve bridge body 2302 aligned with the engine valve stems 2514, 2516. As shown, the same principle of controlled movement on the engine valve stem 2516 can also be applied to the bridge pin 2504 aligned with the auxiliary rocker arm. In this embodiment, it is desirable for any one or both of the engine valve stems 2514, 2516 to have an extension length greater than that of the spring retainers 2506, 2512, for example, up to 10 mm compared to the more typical length of 2 mm to 3 mm.

[0067] Figures 26 to 28 A valve bridge according to a seventh main embodiment is shown. According to a typical valve bridge, the shown valve bridge includes a valve bridge body 2602 spanning at least two engine valves 2604, 2606. In this embodiment, slots 2608 are formed in those portions of the valve bridge body 2602 configured to contact the stems of the engine valves 2604, 2606. Specifically, as... Figure 28 As shown in the optimal configuration, slot 2608 may include a laterally extending slot that connects to the receiving portion 2802 and the engine valve stem 2604. Figure 28The longitudinal axis 2806 of the at least one (only one shown) is transversely intersected. When the engine valve stem 2604 is aligned with and inserted into the corresponding receptacle 2802, the annular channel 2804 formed in the engine valve stem 2604 is aligned with the slot 2608. The C-clip 2702 is inserted into the slot 2608 and engages the annular channel 2804 such that the C-clip 2702 is retained on the engine valve stem 2604. Once retained on the engine valve stem 2604, further engagement of the C-clip 2702 with the slot 2608 allows the C-clip 2702 to resist disengagement of the engine valve stem 2604 from the receptacle 2802, for example, during uncontrolled movement of the valve bridge body 2602. Although the slot 2608 is shown as extending transversely away from the valve bridge body 2602, this is not a requirement. For example, the slot 2608 can instead extend perpendicularly from the plane of the Figures 26 to 28 Figure 28 Although the slot 2608 is shown as extending transversely away from the valve bridge body 2602, this is not a requirement. For example, the slot 2608 can instead extend perpendicularly from the plane of the

[0068] Figure 29 is a side view of a valve bridge according to an eighth primary embodiment. In this embodiment, the valve bridge body 2902 includes a protrusion 2904 extending downward from a lower surface 2908 of the valve bridge body 2902 and positioned between at least two engine valve stems (not shown). As further shown, the protrusion 2904 further includes at least one hook-like feature 2906 (only one shown) extending below and away from the protrusion 2904 toward at least one spring retainer 2910 such that the hook-like or latching feature 2906 extends past an outer circumference of the at least one spring retainer 2910. When the valve bridge body 2902 is in an uncontrolled state, the hook-like feature 2906 will contact an underside 2912 of the valve spring retainer 2910 and prevent the valve bridge body 2902 from disengaging from the engine valve stems to the point of complete disengagement of the valve bridge body from the engine valve stems. Similar to the fifth embodiment described above with respect to Figure 25 the increased radius spring retainer 2910 can provide a protruding edge of material that extends beyond an outer circumference of the corresponding valve spring 2914. In this way, the hook-like feature 2906 is able to better engage the spring retainer 2910 and thereby better ensure resistance to disengagement of the valve bridge.

[0069] As further shown, a peripheral shape 2916 of the protrusion 2904 is configured to allow the valve bridge body 2902 to move downward on one of the engine valves (far right, as shown in Figure 29 Figure 29 ​​As depicted in the middle, the valve bridge is tilted (as in the case of auxiliary valve actuation motion) and without contacting the springs 2914, 2918. Based on the shown configuration, installation of the valve bridge is facilitated by first installing the left side and then rotating the valve bridge down onto the right-most engine valve stems (and corresponding bridge pins 2920). While the bridge pins 2920 are secured by a separate auxiliary rocker arm or its integrated actuator piston (not shown), the bridge cannot be removed due to the latching effect of the hook feature 2906.

[0070] Figure 30 and Figure 31 A valve bridge and bridge pin according to a ninth main embodiment is shown. In this embodiment, the valve bridge body 3002 contains open, laterally extending slots 3004, 3006 configured to receive corresponding bridge pins 3008, 3010 between respective arms 3022, 3024 defined by the slots 3004, 3006 extending into the valve bridge body 3002. As Figure 31 As best shown in the middle, each bridge pin 3008, 3010 has a receptacle 3102 formed therein and configured to receive a corresponding engine valve stem 3012. As shown, each of the bridge pins 3008, 3010 has a spool-like shape containing a barrel 3016 and an end cap 3018, 3020 of increased diameter (relative to the barrel 3016). The slots 3004, 3006 are configured such that the arms 3022, 3024 maintain a relatively tight gap with the barrel 3016 of their respective bridge pins 3008, 3010. On the other hand, the slots 3004, 3006 are configured such that the arms 3022, 3024 will come into contact with the end caps 3018, 3020. In this way, vertical movement of the bridge pins 3008, 3010 is limited by the gap 3104 between the upper (and / or lower) surface of the arms 3022, 3024 and the complementary surface defined by the end caps 3018, 3020. In this way, if the valve bridge body 3002 experiences uncontrolled movement, the limit placed on the valve bridge body 3002 by the bridge pins 3008, 3010 prevents disengagement from the engine valve stems 3012, 3014. It should be noted that similar Figure 24 As shown in the third main embodiment, the upper surface 3026 of the valve bridge body 3002 can be configured such that the spacing between the upper surface 3026 and the end cap 3010 is configured to further limit upward travel of the valve bridge body 3002.

[0071] Figure 32 A valve actuation system according to the prior art is shown. In particular, a valve actuation system is known in which the valve bridge is tilted (as in the case of auxiliary valve actuation motion) and without contacting the springs 2914, 2918. Based on the shown configuration, installation of the valve bridge is facilitated by first installing the left side and then rotating the valve bridge down onto the right-most engine valve stems (and corresponding bridge pins 2920). While the bridge pins 2920 are secured by a separate auxiliary rocker arm or its integrated actuator piston (not shown), the bridge cannot be removed due to the latching effect of the hook feature 2906. Figure 1The collapse mechanism portion of the collapse mechanism shown in FIG. 32 is deployed in the rocker arm 3202 or push rod 3204, rather than in the valve bridge 3206 as depicted in many of the previously described embodiments. As is known in the art, the rocker arm 3202 is well engaged on the rocker shaft 3208, however, if excessive lash is created in the valve train, such valve actuation systems provide the valve bridge 3206 with the opportunity to enter an uncontrolled state. For example, a sudden collapse in the push rod 3204 can allow the rocker arm to rotate rearward (i.e., toward the push rod 3204) an amount equal to the sudden elimination of valve lift. If the valve lift lost thereby is relatively high (e.g., 14 mm in some systems), the sudden rearward rotation of the rocker arm 3202 can cause the rocker arm 3202 to impact the valve cover 3210 or other object. Because the rocker arm 3202 is generally dependent on the valve bridge 3206 to remain engaged with the engine valve stem, the sudden rearward rotation of the rocker arm 3202 in combination with the rapid acceleration of the valve bridge 3206 under the influence of the valve spring will cause the valve bridge to move in an uncontrolled manner, resulting in a disengagement.

[0072] To prevent the valve bridge 3206 from disengaging in such a situation, a stop can be provided to prevent excessive rotation of the rocker arm 3202 that would otherwise allow the valve bridge 3206 to exit. Figure 33 An example of such a situation is shown in FIG. 33, where a rigid or fixed stop 3302 is deployed to prevent rearward rotation of the rocker arm 3202. In the embodiment shown, the fixed stop 3302 is rigidly attached to the rocker shaft 3208, and in this example contains a vertical surface 3304 and a horizontal surface 3306 surface that are configured to engage surfaces of the rocker arm 3202 to prevent excessive rotation thereof. The fixed stop 3302 is configured such that the vertical surface 3304 and the horizontal surface 3306 do not interfere with the normal reciprocation of the rocker arm 3202 (i.e., in a controlled state). However, the fixed stop 3302 is also configured such that the vertical surface 3304 and the horizontal surface 3306 are positioned to prevent excessive rotation of the rocker arm 3202.

[0073] For example, the rocker arm 3202 shown can include a rear-facing surface 3308, which in this case is defined by a control valve boss formed in the rocker arm 3202. In the event of a sudden rearward rotation, the rear-facing surface 3308 will contact the vertical surface 3304 and prevent excessive rotation of the rocker arm 3202. Similarly, the rocker arm further contains an upward-facing surface 3310. In the event of a sudden rearward rotation, the upward-facing surface 3310 will contact the horizontal surface 3306 and prevent excessive rotation of the rocker arm 3202. Although the embodiment shown includes both a vertical surface 3304 and a horizontal surface 3306, this is not a requirement, as either such surface is expected to be sufficient to prevent excessive rotation depending on the configuration of the rocker arm 3202.

[0074] Figure 34and Figure 35 A valve bridge and valve bridge guide according to an eleventh embodiment is shown. In this embodiment, a valve bridge guide 3404 is provided that is attached to (or integrally formed with) a valve bridge body 3402. As shown, the valve bridge guide 3404 is deployed on a side of the valve bridge body 3402 that is not intended to interface with engine valves (not shown) that can also be actuated by an auxiliary motion source. In the illustrated embodiment, the valve bridge guide 3404 is shaped as a semi-cylindrical wall that is configured to be attached to a lower surface 3502 of the valve bridge body 3402 such that the semi-cylindrical wall extends downward from the lower surface 3502. However, it should be understood that the valve bridge guide 3404 can be attached at some other surface (e.g., an upper surface) of the valve bridge body 3402 so long as the semi-cylindrical wall extends downward below the lower surface 3502 as shown.

[0075] Figure 36 A valve bridge and valve bridge guide deployed in a valve actuation system is shown. Figure 34 and Figure 35 As shown, the valve bridge body 3402 spans two engine valve stems, and the valve bridge guide 3404 encloses the outer lateral portions of the valve spring retainers 3602. The radius of the semi-cylindrical wall (preferably centered about or near the longitudinal axis of the corresponding engine valve stem) is configured such that, during normal (i.e., controlled) operation of the valve bridge, there is no contact between the semi-cylindrical wall and the valve spring retainers 3602 or the corresponding valve springs 3604. On the other hand, the radius of the semi-cylindrical wall is further configured such that, during an uncontrolled state of the valve bridge body 3402, the semi-cylindrical wall will contact the valve spring retainers 3602 but avoid contact with the valve springs 3604. Similar to the embodiments described above with respect to Figure 25 and Figure 29 , a spring retainer of increased radius can be employed to better ensure contact between the valve spring retainers 3602 and the valve bridge guide 3404 (and preferably not the valve springs 3604).

[0076] As described above, the present disclosure describes various embodiments and variations of valve bridge guides that can be used to resist (i.e., prevent, minimize, or accommodate) uncontrolled movement of a valve bridge. While various features have been described in connection with particular embodiments, those skilled in the art will understand that various of such features can be combined with other embodiments described herein. For example, some of the features for retaining the disclosed valve bridge guides on a valve bridge can be interchanged. Thus, the fastener systems described in connection with Figure 5 and Figure 6 are equally applicable to the embodiments shown in Figure 7 and Figure 8 , and vice versa.

Claims

1. A valve bridge for use with an engine valve assembly of an internal combustion engine, the engine valve assembly comprising at least two engine valves, wherein the at least two engine valves are actuated by a main rocker arm, and a first engine valve of the at least two engine valves is actuated by an auxiliary rocker arm via a bridge pin, the valve bridge comprising: A valve bridge body configured to extend between at least two engine valves, the valve bridge body including a through-hole configured to align with and receive the bridge pin of a first engine valve, the valve bridge body further including a receiving portion configured to align with and receive a rod of a second engine valve of the at least two engine valves; and An upper surface, formed on the valve bridge body and having a height such that when the valve bridge is in an uncontrolled state relative to the at least two engine valves, the upper surface contacts the surface of the main rocker arm or the auxiliary rocker arm to resist uncontrolled movement of the valve bridge.

2. The valve bridge according to claim 1, wherein the valve bridge further comprises: A bridge pin boss having a through hole formed therein, the bridge pin boss terminating on the upper surface.

3. The valve bridge according to claim 1, wherein the valve bridge further comprises: A portion of the valve bridge body aligned with the main rocker arm terminates on the upper surface.

Images