Valve bridge comprising a concave chamber

Abstract

A valve bridge includes a central body and at least first and second valve interface portions extending from the central body, each of the at least first and second valve interface portions defining a chamber configured to receive an engine valve and corresponding valve spring and spring retainer. Each chamber includes a valve bridge control surface configured to selectively contact at least one of the corresponding valve spring and spring retainer, wherein each valve bridge control surface is a concave surface configured to extend downward around the corresponding valve spring.

Description

Technical Field

[0001] This disclosure generally relates to valve actuation systems in internal combustion engines, and more particularly to valve bridge systems including valve bridge guides used in conjunction with such valve actuation systems. Background Technology

[0002] Valve actuation systems for internal combustion engines are known in the art. Such valve actuation systems typically include a valve mechanism, 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 typically found in a valve mechanism is a so-called valve bridge, which includes means spanning two or more engine valves associated with a given cylinder. In many cases, such a valve bridge allows another component of the valve mechanism (e.g., a rocker arm) to simultaneously actuate two other engine valves engaged with the valve bridge. Ideally, in operation, the opposing forces exerted by the motion transmission components (e.g., rocker arms) and the engine valve springs ensure that the valve bridge remains in contact with both the motion transmission components and the engine valves simultaneously (allowing for normal clearance setting). In this way, the valve bridge always remains aligned with and positioned to transmit valve actuation motion to the engine valves. As used herein, this state of the valve bridge is referred to as the “controlled state” of the valve bridge relative to the engine valves.

[0003] Some valve actuation systems are configured to provide so-called auxiliary valve actuation motion, that is, valve actuation motion other than that used to operate the engine in a positive power generation mode through fuel combustion. In such valve actuation systems, the valve bridge may be configured to include a device or idling assembly that allows valve actuation motion to be transmitted to the engine valves via the valve bridge, or selectively “idles” when such motion is not transmitted to the engine valves via the valve bridge. Figure 1A system described in U.S. Patent Application Publication No. 2012 / 0024260 is shown, the teachings of which are incorporated herein by reference. In this case, the valve bridge 710 is provided with a idling 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 engage with a recess 770 formed in the body of the valve bridge. In this state, the ball 740 is prevented from disengaging from the recess 770 due to the outer diameter of the inner plunger 760, thereby locking the outer plunger 720 in a fixed relationship relative to the valve bridge 710. Therefore, any valve actuation movement applied to the outer plunger 720 by the rocker arms 200 / 400 is transmitted to the valve bridge 710 and the engine valves 810 / 910, 820 / 920. However, when the recess formed in the inner plunger 760 aligns 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 this type, there is a possibility that the locking mechanism may partially engage. In this case, valve actuation motion can be initially applied to the engine valves, causing them to lift off their valve seats. However, due to the partial engagement of the locking mechanism, the increased load or vibration in the valve actuation system causes the locking mechanism to rapidly switch from a partially locked state to an unlocked state. When this occurs, the force provided by the valve actuation motion to open the engine valve is abruptly eliminated, allowing the engine valve to accelerate rapidly to the closed position without restriction under considerable force from the valve spring. When the engine valve reaches the fully closed position (i.e., stops on the valve seat formed in the cylinder head), the momentum applied to the valve bridge can cause it to continue along an uncontrolled trajectory generally away from the engine valve until it strikes the rocker arm or some other object. In fact, the valve bridge may detach from either end of the engine valve, causing it to move away from the engine valve and potentially damaging the engine. This type of movement is referred to as “uncontrolled movement” of the valve bridge, and as used herein, this state of the valve bridge is referred to as the “uncontrolled state” of the valve bridge relative to the engine valve. It is also known that the uncontrolled state of the valve bridge occurs due to the overspeed operation of the internal combustion engine.

[0005] Given this possibility of failure, solutions that prevent, minimize, or adapt to uncontrolled states of the valve bridge (regardless of the cause) would represent a welcome addition to existing technologies. Summary of the Invention

[0006] This disclosure describes a valve bridge for use with an engine valve assembly of an internal combustion engine, the engine valve assembly including 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. The valve bridge includes a central body and at least a first valve interface portion and a second valve interface portion extending from the central body. Each of the at least first and second valve interface portions defines a chamber configured to receive an engine valve from the at least two engine valves and a corresponding valve spring and spring retainer from the at least two valve springs and at least two spring retainers. Each chamber includes a valve bridge control surface configured to selectively contact at least one of the corresponding valve spring and spring retainer, wherein each valve bridge control surface is a concave surface configured to extend downwardly around the corresponding valve spring. Each valve bridge control surface is configured to not contact the corresponding valve spring and spring retainer when the valve bridge is in a controlled state relative to at least two engine valves, and to contact the corresponding valve spring and spring retainer when the valve bridge is in an uncontrolled state relative to at least two engine valves in order to resist uncontrolled movement of the valve bridge.

[0007] In one embodiment, the central body of the valve bridge includes a hole configured to receive a locking mechanism.

[0008] In one embodiment, each of the at least first and second valve interface portions includes a parallel sidewall that extends laterally away from the central body and defines a corresponding chamber. Furthermore, each valve bridge control surface is defined by the sidewall and an inner surface of the central body. Preferably, for each chamber, the sidewall extends beyond the longitudinal axis of the corresponding engine valve relative to the distal edge of the central body. Additionally, each chamber may be configured to be open in a direction away from the central body.

[0009] In another embodiment, each of the at least first valve interface portion and the second valve interface portion further includes an upper wall defining a corresponding chamber. Each upper wall may include a receiving portion configured to receive the valve stem end of a corresponding engine valve. Attached Figure Description

[0010] The features described in this disclosure are specifically set forth in the appended claims. These features and the accompanying advantages will become apparent from the following detailed description taken in conjunction with the accompanying drawings. One or more embodiments will now be described by way of example only with reference to the drawings, wherein similar reference numerals denote similar elements, and wherein:

[0011] Figure 1 It is a cross-sectional view of a valve actuation system including a valve bridge with a locking mechanism according to the prior art;

[0012] Figure 2 and Figure 3 These are corresponding top isometric sectional views and bottom isometric sectional views of a first main embodiment of a valve actuation system including a valve bridge and valve bridge guides according to the present disclosure;

[0013] Figure 4 This is a schematic diagram showing the relationship between the surfaces of the valve spring and the valve bridge guide according to a first main embodiment;

[0014] Figure 5 and Figure 6 These are corresponding isometric views and sectional views (along section lines VI-VI) of the valve bridge and valve bridge guide of a first variant of the first main embodiment;

[0015] Figure 7 and Figure 8 These are corresponding isometric views and sectional views (along section lines VIII-VIII) of the valve bridge and valve bridge guide of the second variant of the first main embodiment.

[0016] Figure 9 and Figure 10 The corresponding isometric and sectional views (along section line XX) of the valve bridge and valve bridge guide of the third variant of the first main embodiment are shown.

[0017] Figure 11 This is an isometric view of the valve bridge guide according to a fourth variant of the first main embodiment;

[0018] Figure 12 This is an isometric view of the valve bridge and valve bridge guide according to a fifth variant of the first main embodiment;

[0019] Figure 13 This is an isometric view of the valve bridge guide according to the sixth variant of the first main embodiment;

[0020] Figure 14 and Figure 15 These are corresponding isometric and sectional views of the valve bridge guide according to the seventh variant of the first main embodiment;

[0021] Figure 16 This is an isometric view of the valve bridge guide according to the eighth variant of the first main embodiment;

[0022] Figure 17 This is an isometric view of the valve bridge guide according to the ninth variant of the first main embodiment;

[0023] Figures 18 to 21 These are corresponding isometric views, side views, and front views of the valve bridge and valve bridge guide according to the second main embodiment.

[0024] Figure 22 This is a top isometric view of the valve bridge and valve bridge guide according to a first variant of the second main embodiment;

[0025] Figure 23 This is a cross-sectional view of a valve bridge based on existing technology;

[0026] Figure 24 This is a cross-sectional view of the valve bridge according to the third main implementation scheme.

[0027] Figure 25 This is a sectional view of the valve bridge according to the fourth to sixth main implementation schemes;

[0028] Figures 26 to 28 These are the corresponding top isometric views and sectional views of the valve bridge according to the seventh main implementation scheme;

[0029] Figure 29 This is a side view of the valve bridge according to the eighth main implementation scheme;

[0030] Figure 30 and Figure 31 These are corresponding isometric views and sectional views of the valve bridge and bridge pin according to the ninth main implementation scheme;

[0031] Figure 32 This is a partial sectional view of the side of a valve actuation system based on existing technology;

[0032] Figure 33 This is a top isometric view of the valve actuation system according to the tenth embodiment;

[0033] Figure 34 and Figure 35 These are corresponding top isometric views and bottom isometric views of the valve bridge and valve bridge guide according to the eleventh embodiment;

[0034] Figure 36 It is deployed in the valve actuation system Figure 34 and Figure 35 Top isometric view of the valve bridge and valve bridge guide;

[0035] Figure 37 This is a bottom isometric view of the valve bridge according to the twelfth embodiment;

[0036] Figure 38 and Figure 39 These are combined with the engine valve assembly. Figure 37 Side front view and top isometric view of the valve bridge; and

[0037] Figure 40 and Figure 41 They are along such Figure 39 The side frontal sectional view shown is taken from the section lines XLI-XLI and XL-XL. Detailed Implementation

[0038] Figures 2 to 41 Various embodiments of a valve bridge system including valve bridge guides according to this disclosure are shown. Figures 2 to 41 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.

[0039] 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.

[0040] 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 one embodiment, the distance 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 2In the illustrated embodiment, the valve bridge and valve bridge guide form an integral structure, i.e., the integral parts are 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.

[0041] 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 springs of valve springs 208, 210 are deformed (i.e., 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.

[0042] In some cases, it may be undesirable for the valve bridge guide 206 to contact the valve springs 208 and 210, as this would lead to premature degradation of the valve springs 208 and 210. Therefore, it may be desirable to alternatively configure the valve bridge control surface 402 to contact the spring retainers 209 and 211. To achieve this configuration, it may be necessary to determine that the outer diameter of the spring retainers 209 and 211 is larger than the outer diameter of the valve springs 208 and 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 retainers 209 and 211, i.e., the valve bridge control surface 402 is a concave surface relative to the convex outer surface of the spring retainers 209 and 211. Furthermore, such a concave surface is configured such that during the controlled state of the valve bridge, the valve bridge control surface 402 can avoid contact with its corresponding spring retainers 209, 211, and is further configured as close as possible to the valve springs 208, 210 (within manufacturing tolerances) so 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 spring retainers 209, 211.

[0043] Although the various figures shown and described in this disclosure illustrate 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 may be employed if used in conjunction with another feature providing additional control over the uncontrolled movement of the valve bridge 204. For example, in the case of a valve bridge 204 equipped with a bridge pin (see, for example...) Figure 21 In the case of component 2102), a combination of a single valve bridge control surface 402 and a bridge pin can be sufficient.

[0044] Compared to Figure 4 The configuration of the valve bridge control surface 402 according to the preferred embodiment is further described. Figure 4 The valve bridge guide 206 and valve spring 208 are shown schematically in enlarged form. (Alternatively, as described above, Figure 4The valve spring 208 shown can be considered a spring retainer, but for ease of description, only the valve spring 208 is described herein. As shown, the valve bridge guide 206 includes a concave valve bridge control surface 402 adjacent to the outer circumference 408 of the valve spring 208. In practice, the clearance between the valve bridge control surface 402 and the outer circumference 408 is partly based on the manufacturing tolerances of the valve springs 208, 210 (or spring retainers 209, 211) and the valve bridge 204. Additionally, this clearance is based on the clearance of the engine valve end within the receiving portion 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 clearance between the valve spring 208 and the valve bridge control surface 402 should be greater than the tolerances of each part plus the allowed 0.25 mm clearance. In addition, the chamfer at the bottom of the valve bridge 204 should be large enough that if the valve bridge 204 experiences uncontrolled movement over the entire clearance with the valve spring or spring retainer, the valve bridge 204 can still reposition itself on the end of the engine valve.

[0045] like Figure 4 As further shown, the circumferential length of the concave valve bridge control surface 402 (relative to the outer circumference 408 of the spring 208) is defined by opposing edges 404, 406. In this preferred embodiment, the opposing edges 404, 406 are spaced apart such that when the valve bridge guide 206 is positioned during the controlled state of the valve bridge 204, the line 410 intersecting the opposing edges 404, 406, as shown, forms a secant at least relative to the outer circumference 408 of the valve spring 208. With this configuration, it should be understood that, if large enough, movement of the valve bridge guide 206 in either direction indicated by the line 410 (e.g., possibly during the uncontrolled state of the valve bridge 204) will result in contact between the concave valve bridge control surface 402 and the outer circumference 408 of the spring, causing the valve bridge guide 206 to deflect substantially away from the valve spring 208 and toward the other valve spring 210. More generally, any rotational movement of the valve bridge 204 about the axis of the locking mechanism centerline is also restricted to lateral movement in two horizontal planes. Accordingly, and see again... Figure 2 and Figure 3 During the uncontrolled state of 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, thereby effectively suppressing or even eliminating any uncontrolled movement of valve bridge 204 and valve bridge guide 206.

[0046] See now Figure 5 and Figure 6A first variant of the valve bridge guide 502 includes 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 the alternative embodiment shown, valve bridge guide 502 may be made of the same material as valve bridge 204 (e.g., steel); however, in a preferred embodiment, valve bridge guide 502 is formed of a lighter, stronger material that is still softer than 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 valve bridge guides will be apparent to those skilled in the art.

[0047] 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 includes 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 include an open locating pin as shown, but those skilled in the art will recognize that other types of fasteners, such as screws, can be used in the same manner. 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.

[0048] See now Figure 7 and Figure 8 The second variant of valve bridge guide 702 and Figure 5 and Figure 6 The valve bridge 502 is substantially similar in that it comprises an integral part separate from the valve bridge 204, which has a valve bridge control surface 402 formed on its lateral side, as shown. However, in this embodiment, the valve bridge guide 702 includes one or more teeth 802 extending inwardly from the sidewall surface of the opening 602 and is configured to engage a recess 804 formed in the outer sidewall surface of the portion 604 of the valve bridge 204. For example, the recess 804 may include an annular groove or channel formed in the sidewall of the portion 604 of the valve bridge 204. When the teeth 802 engage the recess 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 in this embodiment, the arrangement of one or more teeth 802 and notches 804 can be reversed, that is, teeth 802 can be formed on the outer wall surface of portion 604 of valve bridge 204, while notches 804 are formed on the inner wall surface of opening 602.

[0049] like Figure 7 As further shown, the valve bridge guide 702 may include at least two protruding members 704, 706 projecting from the valve bridge guide 702 toward the valve bridge 204. Figure 8 As shown, the valve bridge 204 has a lower surface 806, and in one embodiment, the protruding members 704, 706 extend at least beyond the lower surface 806 of the valve bridge 204. In this embodiment, 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 way, 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.

[0050] See now Figure 9 and Figure 10A third variation of the valve bridge guide 902 is shown, wherein the valve bridge guide 902 is again formed as a separate integral part of the valve bridge 204, having a valve bridge control surface 402 formed on its lateral side, as shown. However, in this embodiment, the valve bridge guide 902 has a side opening 904 with a cantilever latch or clip 906 disposed therein. As shown, the clip 906 is configured to engage a corresponding recess 1002 formed in the outer sidewall surface of a portion 604 of the valve bridge 204. For example, the recess 1002 may again include an annular groove or channel formed in the sidewall of the portion 604 of the valve bridge 204. When the clip 906 engages the recess 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 in the figure, the valve bridge guide 902 may further include an auxiliary latching surface 908 configured to engage a corresponding auxiliary recess 1004 formed in a 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.

[0051] See now Figure 11 This illustrates a fourth variant of the valve bridge guide 1102. In this variant, the valve bridge guide 1102 is integrally disposed between the spring retainers 209, 211 and the valve bridge 204. Recesses 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 may be provided, which allows a portion of the valve bridge 204 (e.g., to accommodate...) Figure 1 The portion of the locking mechanism shown extends through the valve bridge guide 1102. Similar to... Figure 7 and Figure 8 In one embodiment, the valve bridge guide 1102 includes at least two protruding members in the form of sidewalls 1108, 1110 defining a channel 1107, which is further configured to receive the valve bridge 204. In this embodiment, the inner surfaces 1112, 1114 of the sidewalls 1108, 1110, raised above the valve bridge 204, serve as valve bridge control surfaces that prevent lateral movement or rotation of the valve bridge 204 that may occur during an uncontrolled state of the valve bridge 204. Furthermore, although Figure 11Not shown, but an additional valve bridge control surface 402 may optionally be provided on the lower portion 1118 of the valve bridge guide 1102 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 end) will cause a similar lifting in the valve bridge guide 1102, which again resists uncontrolled movement and allows the valve bridge 204 to return stably to the engine valve end.

[0052] See now Figure 12 The fifth variant of valve bridge guide 1202 and Figure 5 and Figure 6 The valve bridge 502 is substantially similar in that it comprises an integral part separate from the valve bridge 204, which has a valve bridge control surface 402 formed on its lateral sides, as shown. As further shown, and similar to... Figure 7 and Figure 8 The second variant shown, this embodiment of the valve bridge guide 1202, further includes a plurality of protruding members 1204 to 1212 extending upward from the body of the valve bridge guide 1202, these protruding members serving a similar purpose as described above. Additionally, as shown, each of the protruding members 1204 to 1212 includes an attachment surface 1214, 1216 in the form of inwardly extending fingers 1214, 1216 disposed at the end of the protruding members 1204 to 1212. Figure 12 (Only two are shown in the image). The thus defined attachment surfaces are configured to engage the corresponding surface 1220 of the valve bridge 204, in this case, the upper surface of the valve bridge 204. In this way, the valve bridge guide 1202 is held on the valve bridge 204. Alternatively, and similarly... Figure 9 and Figure 10 In one embodiment, the fingers 1214 and 1216 may alternatively engage with a notch or similar feature formed in the lateral side of the valve bridge 204.

[0053] Figure 13A sixth variation of the first embodiment is shown, wherein the valve bridge guide 1302 is formed by 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 the valve bridge control surface 402 as described above. Furthermore, 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., a portion of the valve bridge extending from the center of the valve bridge to one of the engine valves). Furthermore, one of the guide members 1304 and 1306 includes a fastener in the form of a complementary first latch 1312 and a first latch recess 1314, and a second latch 1316 and a second latch recess 1318, such that the guide members 1304 and 1306 can be securely connected to each other. Alternatively, any of the aforementioned attachment mechanisms (locating pins, epoxy resin, etc.) can be used as a "fastener" for this purpose. When connected, the guide members 1304 and 1306 together define the valve bridge guide 1302, which remains in place relative to the valve bridge 204 because the second opening 1310 surrounds the arm of the valve bridge 204.

[0054] Figure 14 and Figure 15 A seventh variant of the first main embodiment is shown, wherein the valve bridge guide 1402 is formed as a stamped sheet metal structure having a horizontal surface 1404 and continuous sidewalls 1406 extending downward therefrom. In this variant, similar to Figure 11 In the illustrated embodiment, the valve bridge guide 1402 is designed to rest on the spring retainers 209, 211 ( Figure 15 On top of and below valve bridge 204 (not shown). Figure 15 In the diagram, sidewall 1406 is shown as an initial portion extending through spring retainers 209, 211 and valve springs 208, 210. In this embodiment, the extent of sidewall 1406 prevents valve bridge guide 1402 from being fully lifted away from spring retainers 209, 211, despite any vertical displacement applied to valve bridge 204. In addition to a central opening 1418 allowing a portion of valve bridge 204 to pass through, valve bridge guide 1402 includes a plurality of protruding members 1408 to 1416 (four shown in the illustrated example), which are similar to... Figure 7 , Figure 8 , Figure 11 and Figure 12The protruding members shown are, as illustrated, formed as upwardly curved portions of a horizontal surface 1404, resulting in openings 1426, 1428 that allow the ends of engine valves 1502 to pass through. In this configuration, protruding members 1408 to 1416 again define valve bridge control surfaces 1422, 1424 to resist uncontrolled movement of the valve bridge 204.

[0055] Figure 16 An isometric view of an eighth variant of the first main embodiment is shown, wherein the valve bridge guide 1602 includes 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 sheet metal structure having a horizontal surface 1604 and continuous sidewalls 1606 extending downward therefrom, similar to Figure 14 and Figure 15 The implementation scheme is configured to rest only on top of a single spring retainer 209. Similarly, each guide member 1603 includes a plurality of upwardly extending protrusions 1608, 1610 and a central opening 1612 for the passage of engine valve ends, wherein each of the protrusions 1608, 1610 defines a valve bridge control surface 1614 for resisting uncontrolled movement of the valve bridge 204.

[0056] Similar to Figure 16 Implementation plan, Figure 17 The illustrated embodiment includes a valve bridge guide 1702 comprising a pair of guide members 1703 configured to rest on top of separate spring retainers 209, 211. In this configuration, formed from a moldable polymer, each guide member 1703 includes a horizontal surface 1704 and a continuous sidewall 1706 extending downward therefrom, similar to... Figure 14 and Figure 15 The implementation scheme, however, is configured to rest solely on top of a single spring retainer 209, as... Figure 16 The implementation scheme is as follows. Similarly, each guide member 1703 includes a plurality of upwardly extending protrusions 1708, 1710 and a central opening 1712 for the passage of engine valve ends, wherein each of the protrusions 1708, 1710 defines a valve bridge control surface 1714 for resisting uncontrolled movement of the valve bridge 204. However, in this case, each guide member 1703 is also provided with a laterally concave valve bridge control surface 402 as described above. However, in this case, the laterally concave valve bridge control surface 402 is not configured to conform to the outer surfaces of the valve springs 208, 210, but rather to conform to a portion of the valve bridge 204 that extends downward between the valve springs 208, 210 and accommodates the locking mechanism, as described above relative to... Figure 1As stated and shown.

[0057] See now Figures 18 to 21 The illustration shows a second main embodiment according to the present disclosure, wherein the 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, although each valve bridge can actuate more than two engine valves again. In the illustrated embodiment, a 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 and a valve spring retainer 209, 211, the valve spring biasing its corresponding engine valve to a closed state, and the valve spring retainer being attached to the valve stem of the engine valve. Figure 19 As shown in the best embodiment, the valve bridge 204 includes a lower surface 1902 facing the engine valve and an upper surface 1904 opposite to the lower surface 1902.

[0058] As further shown in this second main embodiment, the valve bridge system further includes 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 (e.g., bolts screwed into the cylinder head or similar fixing structures), the first member 1802 is held in a first fixed position relative to the valve bridge 204. Specifically, when at least two valve bridges 204, 212 are held in the closed state, the first fixed position holds the first member 1802 at a predetermined distance 1908 from the upper surface 1904 of the valve bridge 204. Additionally, as shown, the first fixed position of the first member 1802 is aligned with a first engine valve of at least two engine valves, wherein the first engine valve is furthest from the rocker arm shaft 1808 of the internal combustion engine 202. As shown, the first member 1802 can be configured such that it is aligned with a first engine valve as described for more than one valve bridge 204, 212. In addition, the first component 1802 may also extend across the valve bridges 204, 212 for multiple cylinders of the internal combustion engine in this manner, or may include multiple such first components 1802, wherein the cylinder configuration prevents the use of a single first component 1802.

[0059] In this embodiment, a 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 Various variations of the first embodiment shown counteract this, resulting in 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 reception 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 upwards, for example, by about 1 mm to 2 mm. Therefore, the predetermined distance 1908 should be selected to accommodate the possibility of 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 upwards over time, and the predetermined distance 1908 should also take this possibility into account.

[0060] In this second embodiment, the valve bridge guide may further include a second member 1804, which is held in a second fixed position relative to the valve bridge 204 and has a second surface 1910 facing the upper surface 1904 of the valve bridge 204. Similar to 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 this embodiment, the second fixed position of the second member 1804 is aligned with a second engine valve of at least two engine valves, wherein the second engine valve is closest to the rocker arm shaft 1808. Furthermore, as... Figure 18 and Figure 19 As shown in the optimal configuration, the second component 1804 can be integrally formed with the rocker arm base 1810. In this way, the first component 1802 and the second component 1804 can be separately aligned with different engine valves and are equidistant from the upper surface 1904 by a predetermined distance 1908, thereby acting as valve bridge guides to provide uniform resistance to uncontrolled movement.

[0061] As is known in the art, some valve actuation systems include auxiliary motion sources and valve mechanisms that provide auxiliary motion to individual engine valves despite the presence of valve bridge 212. This is achieved by using bridge pin 2102, as is known in the art, thereby allowing auxiliary valve actuation motion to be applied to individual engine valves, and main valve actuation motion to be applied to individual engine valves via valve bridge 212. In this case, the presence of bridge pin 2102 through valve bridge 212 effectively serves as a second member 1804 defining valve bridge guides. That is, if valve bridge 212 operates in an uncontrolled state, the presence of bridge pin 2102 (operably connected to both auxiliary rocker arm 2104 and individual engine valves) will operate to restrict valve bridge 212 to sliding motion only relative to bridge pin 2102. In this case, the presence of auxiliary rocker arm 2104 (or other auxiliary valve mechanism assembly) will operate to prevent valve bridge 212 from disengaging from bridge pin 2102. Similarly, in the case of providing first member 1802 (e.g. Figure 21 As shown), the combined operation of the first component 1802 and the second component 1804 will resist the uncontrolled movement of the valve bridge 212, especially its upward movement.

[0062] Figure 22 A first variant of the second embodiment is shown, wherein the valve bridge guide includes a first member 2202 formed as a three-sided arch or "band". Similar Figures 18 to 21 Implementation plan, 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 (As shown in the diagram), 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 Similar to the implementation scheme, 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.

[0063] 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.

[0064] Figure 24 A valve bridge according to a third main embodiment is shown, wherein a structure 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.

[0065] 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.

[0066] See now Figure 25 The diagram shows valve bridges according to the fourth through 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 involves a feature relating to the clearance between the inner diameter of the through-hole 2502 and the outer diameter of the bridge pin 2504. Specifically, 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.

[0067] 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 engage more quickly at 2511 with the increased radius spring retainer 2506 during uncontrolled movement (particularly rotation of the valve bridge body 2302), thereby resisting further rotation of the valve bridge body 2302.

[0068] 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.

[0069] 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 axes 2806 (shown only one in the diagram) intersect laterally. When the engine valve stem 2604 is aligned with and inserted into the corresponding receiving portion 2802, the annular channel 2804 formed in the engine valve stem 2604 aligns with the slot 2608. The C-shaped clamp 2702 is inserted into the slot 2608 and engages the annular channel 2804, such that the C-shaped clamp 2702 is held on the engine valve stem 2604. Once held on the engine valve stem 2604, further engagement of the C-shaped clamp 2702 with the slot 2608 allows the C-shaped clamp 2702 to resist disengagement of the engine valve stem 2604 from the receiving portion 2802, for example, during uncontrolled movement of the valve bridge body 2602. Although the slot 2608 is in Figures 26 to 28 The diagram shows a lateral extension away from the valve bridge body 2602, but this is not a requirement. For example, slot 2608 can alternatively extend from... Figure 28 The plane extends vertically, that is, it extends perpendicularly to the longitudinal axis of the valve bridge body and perpendicularly to the longitudinal axis 2806 of the engine valve stems 2604 and 2606.

[0070] Figure 29 This is a side view of the valve bridge according to an eighth main embodiment. In this embodiment, the valve bridge body 2902 includes a protrusion 2904 extending downward from the lower surface 2908 of the valve 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-shaped feature 2906 (only one shown) extending below and toward at least one spring retainer 2910 away from the protrusion 2904, such that the hook-shaped or latching feature 2906 extends past the outer circumference of the at least one spring retainer 2910. When the valve bridge body 2902 is in an uncontrolled state, the hook-shaped feature 2906 will contact the lower side 2912 of the valve spring retainer 2910 and prevent the valve bridge body 2902 from separating from the engine valve stems to the point where the valve bridge body is completely disengaged from the engine valve stems. Similar to the above description... Figure 25 In the fifth embodiment described, the increased radius spring retainer 2910 may provide a protruding edge of material extending beyond the outer circumference of the corresponding valve spring 2914. In this way, the hook-shaped feature 2906 can better engage the spring retainer 2910, and thereby better ensure resistance to valve bridge disengagement.

[0071] like Figure 29 As further shown, the 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 (the rightmost one, as shown). Figure 29As depicted, the valve bridge is tilted (as in the case of auxiliary valve actuation) and without contacting springs 2914 and 2918. Based on the configuration shown, valve bridge installation is facilitated by first installing the left side and then rotating the valve bridge downwards onto the rightmost engine valve stem (and corresponding bridge pin 2920). Although bridge pin 2920 is 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-shaped feature 2906.

[0072] Figure 30 and Figure 31 A valve bridge and bridge pins according to a ninth main embodiment are shown. In this embodiment, the valve bridge body 3002 includes open, laterally extending slots 3004, 3006 configured to receive corresponding bridge pins 3008, 3010 between corresponding arms 3022, 3024 defined by the slots 3004, 3006 extending into the valve body 3002. Figure 31 As shown in the figure, each bridge pin 3008, 3010 has a receiving portion 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, which includes a cylindrical body 3016 and end caps 3018, 3020 with increased diameters (relative to the cylindrical body 3016). Slots 3004, 3006 are configured such that arms 3022, 3024 maintain a relatively tight clearance with the cylindrical body 3016 of their respective bridge pins 3008, 3010. On the other hand, slots 3004, 3006 are configured such that arms 3022, 3024 will contact end caps 3018, 3020. In this manner, the vertical movement of the valve bridge pins 3008 and 3010 is limited by the distance 3104 between the upper (and / or lower) surfaces of the arms 3022 and 3024 and the complementary surfaces defined by the end caps 3018 and 3020. In this manner, if the valve bridge body 3002 experiences uncontrolled movement, the restriction imposed by the valve bridge pins 3008 and 3010 on the valve bridge body 3002 prevents disengagement from the engine valve stems 3012 and 3014. It should be noted that similar... Figure 24 In the third main embodiment shown, the upper surface 3026 of the valve bridge body 3002 can be configured such that the gap between the upper surface 3026 and the end cap 3010 is configured to further restrict the upward movement of the valve bridge body 3002.

[0073] Figure 32 A valve actuation system according to the prior art is shown. In particular, valve actuation systems similar to... Figure 1The collapse mechanism shown is deployed in the rocker arm 3202 or pushrod 3204, rather than in the valve bridge 3206 as depicted in many previously described embodiments. As is known in the art, the rocker arm 3202 engages well with the rocker arm shaft 3208; however, if excessive clearance is formed in the valve mechanism, such a valve actuation system provides the valve bridge 3206 with an opportunity to enter an uncontrolled state. For example, a sudden collapse in the pushrod 3204 can allow the rocker arm to rotate rearward (i.e., toward the pushrod 3204) equal to the sudden elimination of valve lift. If the resulting loss of valve lift is relatively high (e.g., 14 mm in some systems), the sudden rearward rotation of the rocker arm 3202 may cause the rocker arm 3202 to strike the valve cover 3210 or other objects. Because the rocker arm 3202 typically relies on maintaining the engagement of the valve bridge 3206 with the engine valve stem, the sudden rearward rotation of the rocker arm 3202 combined 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 disengagement.

[0074] To prevent the valve bridge 3206 from disengaging in this situation, a stop can be provided to prevent excessive rotation of the rocker arm 3202, which would otherwise allow the valve bridge 3206 to disengage. Figure 33 An example of this situation is shown, in which a rigid or fixed stop 3302 is deployed to prevent the rocker arm 3202 from rotating rearward. In the illustrated embodiment, the fixed stop 3302 is rigidly attached to the rocker arm shaft 3208 and, in this example, includes vertical surface 3304 and horizontal surface 3306, which are configured to engage with the surface of the rocker arm 3202 to prevent its over-rotation. The fixed stop 3302 is configured such that the vertical surface 3304 and horizontal surface 3306 do not interfere with the normal reciprocating motion 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 horizontal surface 3306 are positioned to prevent over-rotation of the rocker arm 3202.

[0075] For example, the illustrated rocker arm 3202 may include a rearward-facing surface 3308, in which case the rearward-facing surface is defined by a control valve boss formed in the rocker arm 3202. In the event of a sudden rearward rotation, the rearward-facing surface 3308 will contact the vertical surface 3304 and prevent excessive rotation of the rocker arm 3202. Similarly, the rocker arm further includes 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 illustrated embodiment includes both the vertical surface 3304 and the horizontal surface 3306, this is not a requirement, as either such surface is contemplated to be sufficient to prevent excessive rotation depending on the configuration of the rocker arm 3202.

[0076] Figure 34 and Figure 35 A valve bridge and valve bridge guide according to an eleventh embodiment are shown. In this embodiment, a valve bridge guide 3404 is provided, which is attached to (or integrally formed with) a valve bridge body 3402. As shown, the valve bridge guide 3404 is deployed on one side of the valve bridge body 3402, which is not intended to engage with an engine valve (not shown) that can also be actuated by an auxiliary motion source. In the illustrated embodiment, the valve bridge guide 3404 is formed as a semi-cylindrical wall configured to attach 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 may be attached to some other surface of the valve bridge body 3402 (e.g., an upper surface), as long as the semi-cylindrical wall extends downward below the lower surface 3502 as shown.

[0077] Figure 36 This shows the deployment in the valve actuation system. Figure 34 and Figure 35 The valve bridge and valve bridge guide. As shown, the valve bridge body 3402 spans two engine valve stems, and the valve bridge guide 3404 surrounds the outer lateral portion of the valve spring retainer 3602. The radius of the semi-cylindrical wall (preferably centered on 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 retainer 3602 or the corresponding valve spring 3604. On the other hand, the radius of the semi-cylindrical wall is further configured such that during the uncontrolled state of the valve bridge body 3402, the semi-cylindrical wall will contact the valve spring retainer 3602, but avoid contact with the valve spring 3604. Similar to the above description... Figure 25 and Figure 29 The described implementation may employ a spring retainer with an increased radius to better ensure contact between the valve spring retainer 3602 and the valve bridge guide 3404 (and preferably, not the valve spring 3604).

[0078] Figure 37 A twelfth embodiment of the valve bridge 3702 according to the eleventh embodiment is shown. In this embodiment, the valve bridge 3702 includes a central body 3704, which in this example has a first valve interface portion and a second valve interface portion 3706 extending away from the central body 3704. Figure 40 As best shown, the central body 3704 includes a hole 4004 configured to receive a locking mechanism 4002, which is substantially similar to Figure 6 As shown in and as relative to Figure 1The locking mechanism 606 is shown and described. The first valve interface portion and the second valve interface portion 3706 preferably extend relative to each other, away from the central body 3704. Although two valve interface portions 3706 are shown, it should be understood that additional valve interface portions may be used. Preferably, the central body 3704 and the first and second valve interface portions 3706 are formed as a single, integral unit. As described in further detail below, the first and second valve interface portions 3706 are each configured to receive at least a portion of an engine valve and its corresponding valve spring and valve spring retainer.

[0079] Each of the first valve interface portion and the second valve interface portion 3706 includes a chamber 3708 configured to receive an engine valve and its corresponding valve spring and valve spring retainer. (Reference) Figure 38 and Figure 39 Each chamber 3708 extends downward, i.e., toward the engine valve 3804. As further shown, each chamber 3708 is open in a direction away from the central body 3704, thereby allowing reception of the corresponding engine valve, valve spring, and valve spring retainer without completely enclosing these components. Each chamber 3708 is defined by a concave valve bridge control surface, which is defined by inner surfaces 3710, 3712, and 3714, which are respectively provided by the central body 3704 and laterally extending and substantially parallel (within manufacturing tolerances) sidewalls 3716 and 3718. In fact, as Figure 37 As shown, the central body and side walls 3716, 3718 define an "H" shape. Each chamber 3708 is further defined by an upper wall 3720 that surrounds the corresponding chamber 3708 from above. Each chamber also includes a receiving portion 3722 formed in the inner surface of the upper wall 3720, which is configured to receive the end of an engine valve stem, as shown. Figure 40 and Figure 41 As best shown in the image. Figure 37 and Figure 40 As shown, the first receiving portion 3722a is configured in a generally circular shape such that it matches the outer diameter of the end of the engine valve (within manufacturing tolerances), while the second receiving portion 3722b is configured to have an elongated slot-like profile to accommodate the compliance or deflection of the engine valve stem relative to each other.

[0080] refer to Figures 38 to 41The valve bridge 3702 is shown together with the engine valve assembly 3802. Note that in these views, portions of the locking mechanism 4002, particularly the outer plunger 3820 and cap 3822, extend through holes 4004 formed in the central body 3704. In the example shown, the engine valve assembly 3802 includes a pair of engine valves 3804, each having a corresponding valve spring 3806, spring retainer 3808, and spring guide 3810, as is known in the art. Consistent with conventional valve bridges, the valve bridge 3702 is located on top of the engine valves 3804. As shown, at least a portion of each valve spring 3804 and its corresponding valve spring 3806 and spring retainer 3808 are received in a corresponding chamber within the chamber 3708, such that... Figure 40 and Figure 41 As best shown, the end of each valve 3804 is received into a corresponding receiving portion in receiving portion 3722. In the presently preferred embodiment, the lateral lengths of the sidewalls 3716, 3718 away from the central body 3704 are such that the distal edges 3902, 3904 of the sidewalls 3716, 3718 extend beyond the longitudinal axis of the engine valve 3804. An example of this is shown in... Figure 38 Specifically shown, the distal edge 3902 of the first chamber 3708a extends beyond the longitudinal axis 3812 of the first engine valve 3804a by a distance D, wherein D can be selected according to the design.

[0081] like Figure 40 and Figure 41 As best illustrated, the dimensions of the inner surfaces 3710, 3712, and 3714 are selected to provide clearance with the corresponding valve springs 3806 and spring retainers 3808, such that during operation when the valve bridge 3702 is in a controlled state, the valve bridge control surfaces defined by the inner surfaces 3710, 3712, and 3714 will not contact the corresponding valve springs 3806 and spring retainers 3808. Conversely, when the valve bridge is in an uncontrolled state, one or more inner surfaces may contact any one or both of the corresponding valve springs 3806 and spring retainers 3808, thereby minimizing and / or eliminating uncontrolled movement of the valve bridge. Figure 3 and Figure 4 Unlike the embodiment shown, where the valve bridge control surface 402 is configured to reflect the curvature of the corresponding valve spring and / or spring retainer, the valve bridge control surface defined by the inner surfaces 3710, 3712, 3714 does not necessarily conform to the curvature of the valve spring and / or spring retainer, but any one or more of these surfaces 3710, 3712, 3714 can be configured to conform to the curvature of the valve spring and / or spring retainer.

[0082] As described above, this disclosure describes various embodiments and variations of valve bridge guides that can be used to resist (i.e., prevent, minimize, or adapt to) uncontrolled movement of the valve bridge. While various features have been described in conjunction with specific embodiments, those skilled in the art will understand that various features of such features can be incorporated into other embodiments described herein.

Claims

1. A valve bridge for use with an engine valve assembly of an internal combustion engine, the engine valve assembly including 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, the valve bridge comprising: Central main body; At least a first valve interface portion and a second valve interface portion extending from the central body, each of the at least first valve interface portion and the second valve interface portion including two parallel sidewalls extending laterally away from the central body, the two parallel sidewalls defining a chamber configured to receive an engine valve of the at least two engine valves. Each chamber includes a concave valve bridge control surface defined by the two parallel sidewalls and the inner surface of the central body, and configured to selectively contact at least one of the corresponding valve spring and spring retainer. Each chamber is open both laterally and vertically in a direction away from the central body. Each valve bridge control surface is configured to extend downwards around the corresponding valve spring and spring retainer. Each valve bridge control surface is configured to not contact the corresponding valve spring and spring retainer when the valve bridge is in a controlled state relative to the at least two engine valves, wherein the valve bridge is simultaneously in contact with the motion transmission assembly and the at least two engine valves. Furthermore, each valve bridge control surface is configured to contact the corresponding valve spring and spring retainer 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 which the valve bridge disengages from the end of either of the at least two engine valves.

2. The valve bridge of claim 1, wherein the central body includes a hole configured to receive a locking mechanism.

3. The valve bridge according to claim 1, wherein, For each chamber, the distal edges of the two parallel sidewalls extend beyond the longitudinal axis of the corresponding engine valve relative to the central body.

4. The valve bridge according to claim 1, wherein each of the at least first valve interface portion and second valve interface portion includes an upper wall.

5. The valve bridge of claim 4, wherein each upper wall includes a recess configured to receive the valve stem end of the corresponding engine valve.

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