KR20220164060A - A valve bridge system that resists uncontrolled movement of the valve bridge - Google Patents

Abstract

The 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 bore aligned with the first engine valve and configured to receive a bridge pin. The bridge pin boss has a through bore formed therein, has a longitudinal length, and terminates at an upper surface. The longitudinal length is configured so that when the valve bridge is in an uncontrolled state for at least two engine valves, an upper surface of the bridge pin boss contacts a surface of the auxiliary rocker arm to resist uncontrolled movement of the valve bridge. .

Description

A valve bridge system that resists uncontrolled movement of the valve bridge

The present disclosure relates generally to valve actuation systems in internal combustion engines, and more particularly to valve bridge systems including valve bridge guides for use with such valve actuation systems.

Valve actuation systems for internal combustion engines are well known in the art. Typically, such valve actuation systems include a valve train that in turn includes one or more components that transmit valve actuation motion from a valve actuation motion source (eg, one or more cams) to an engine valve. A component commonly seen in valve trains is the so-called valve bridge, which includes devices spanning two or more engine valves associated with a given cylinder. In many cases, these valve bridges allow other components of the valve train (eg, rocker arms) to simultaneously actuate two or more engine valves meshed with the valve bridge. Ideally, in operation, by resistance to the force exerted by the motion transmission component (e.g. rocker arm) and the engine valve spring, the valve bridge moves simultaneously with the motion transmission component and the engine valve (given a typical lash setting). ) can maintain contact. In this way, the valve bridge is held consistently aligned and positioned to impart a valve actuation action 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 valve.

Some valve actuation systems are configured to provide so-called auxiliary valve actuation actions, ie valve actuation actions that are different from or in addition to valve actuation actions used to operate the engine in a positive power generation mode through combustion of fuel. In these valve actuation systems, the valve bridge is a device or loss action that allows valve actuation action to be transferred to the engine valves through the valve bridge, or selectively "lost" if such action is not transferred to the engine valves through the valve bridge. It may be configured to include an assembly. 1 illustrates such a system described in US 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 lossy action 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 external plunger 720 and that can engage a recess 770 formed in the body of the valve bridge. In this state, the ball 740 is prevented from disengaging the recess 770 due to the outer diameter of the inner plunger 760, locking the outer plunger 720 in fixed relation to the valve bridge 710. Consequently, any valve actuation action applied to external plunger 720 by rocker arm 200/400 is transmitted to valve bridge 710 and engine valves 810/910, 820/920. However, when the recess formed in the inner plunger 760 aligns with the ball 740, the ball can separate the recess 770 of the valve bridge 710, unlocking the outer plunger 720 and valve It can reciprocate relative to the bridge 710. In this state, any valve actuation action applied to external plunger 720 causes the external plunger to move within valve bridge 710 and is not transmitted to the engine valve. Another valve bridge based lock/unlock system is disclosed in US Patent Application Publication No. 2014/0326212, the teachings of which are incorporated herein by reference.

However, in a system of the type shown in Figure 1, the possibility of partial meshing of the locking mechanism exists. In this case, the valve actuating action is initially applied to the engine valve, so that the engine valve can be lifted from the valve seat. However, due to the partial engagement of the locking mechanism, when the load or vibration of the valve actuation system increases, the locking mechanism quickly switches from the partially locked state to the unlocked state. When this happens, the force provided by the valve actuation action to open the engine valve is suddenly removed, allowing the engine valve to rapidly accelerate to its closed position in an unconstrained manner under the significant force of the valve spring. When an engine valve reaches its fully closed position (i.e. stops against the valve seat formed in the cylinder head), the momentum applied to the valve bridge causes the valve bridge to move away from the engine valve, usually until it strikes a rocker arm or some other object. It can continue on an uncontrolled trajectory in the direction. In fact, the valve bridge can be removed at either tip of the engine valve to break away from the engine valve, causing engine damage. 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 an uncontrolled state of the valve bridge occurs due to overspeed operation of the internal combustion engine.

Given this possibility of malfunction, a solution to prevent, minimize or counteract the uncontrolled condition of the valve bridge (regardless of the cause) would represent a welcome addition to the present technology.

The present disclosure describes a valve bridge system that overcomes the above-mentioned problems with prior art valve bridge systems. In a first principal embodiment, a valve bridge system includes a valve bridge configured to extend between at least two engine valves of an internal combustion engine. The valve bridge guide is operably connected to the valve bridge and includes a valve bridge or engine valve assembly (at least two engine valves, at least two valve springs corresponding to the at least two engine valves, and at least two valve springs corresponding to the at least two engine valves). and a valve bridge control surface for selectively contacting at least one of the two spring retainers. In this embodiment, the valve bridge guide may be made of a moldable polymer. The valve bridge control surface is configured to avoid contact with the valve bridge or engine valve assembly when the valve bridge is in a controlled state for at least two engine valves, and when the valve bridge is in an uncontrolled state for at least two engine valves. and is further configured to resist uncontrolled movement of the valve bridge in contact with the valve bridge or engine valve assembly when in position. In one embodiment, the valve bridge guide is configured to extend between the at least two valve springs and the valve bridge control surface is at least one corresponding to at least one convex surface formed by the at least two valve springs or the at least two spring retainers. It is a concave surface of the valve bridge, or a convex surface formed by a part of the valve bridge. More specifically, each of the at least one concave surface may be defined by an opposite edge such that a line intersecting the opposite edge forms a secant to an outer diameter of a corresponding one of the at least two valve springs or at least two spring retainers.

The valve bridge guide and valve bridge may form a unitary structure, or the valve bridge guide may include one or more separate components operatively connected to the valve bridge. In one embodiment, the valve bridge guide includes two guide members configured to engage opposite sides of the valve bridge and may further include at least one fastener for operably coupling the two guide members together. The valve bridge guide may include an opening for receiving at least a portion of the valve bridge, and may further include at least two protruding members, each of the at least two protruding members protruding from the valve bridge guide toward the valve bridge; It extends past at least two engine valves and at least a lower surface of the valve bridge that opposes them. Additionally, the at least two protruding members may form a valve bridge control surface. Alternatively, each of the at least two protruding members may include an attachment surface for engaging a corresponding surface of the valve bridge.

In a second main embodiment, the valve bridge system may include a valve bridge configured to extend between at least two engine valves of an internal combustion engine, the valve bridge having a lower surface opposite the at least two engine valves and an upper surface opposite the lower surface. includes The system of this primary 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 moving away from a top surface of the valve bridge when at least two engine valves are in a closed state. and a first surface facing the top surface at a predetermined distance. 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 for the at least two engine valves, and when the valve bridge is in a non-controlled state for the at least two engine valves. and to enable contact between the first surface and an upper surface of the valve bridge to resist uncontrolled movement of the valve bridge when present. If the valve bridge includes a receptacle for receiving an engine valve tip of one of the at least two engine valves, the predetermined distance may be less than the depth of the receptacle.

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

In a further alternative to this second main embodiment, the valve bridge guide may further comprise a bridge pin disposed at one end of the valve bridge and aligned with the engine valves of the at least two engine valves. Alternatively, the first member of the valve bridge guide in this embodiment may include an arch configured to be attached to the cylinder head and extending between the at least two engine valves and over a top surface of the valve bridge, the arch extending to the valve train It further includes an opening formed therein aligned with a portion of the valve bridge in contact with the component.

The features described in this disclosure are particularly pointed out in the appended claims. These features and attendant advantages will become apparent upon consideration of the following detailed description taken in conjunction with the accompanying drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the accompanying drawings, in which like reference numbers indicate like elements, one or more embodiments are described by way of example only.
1 is a cross-sectional view of a valve actuation system comprising a valve bridge with a locking mechanism according to the prior art;
2 and 3 are top isometric and bottom isometric sectional views, respectively, of a first principal embodiment of a valve actuation system including a valve bridge and a valve bridge guide according to the present disclosure;
Fig. 4 is a schematic diagram showing the relationship between the valve spring and the surface of the valve bridge guide according to the first main embodiment;
5 and 6 are respectively isometric and sectional views (along section line VI-VI) of a valve bridge and a valve bridge guide according to a first variant of the first principal embodiment;
7 and 8 are respectively isometric and sectional views (along section line VIII-VIII) of a valve bridge and a valve bridge guide according to a second variant of the first principal embodiment;
9 and 10 are respectively isometric and sectional views (along section line XX) of a valve bridge and a valve bridge guide according to a third variant of the first principal embodiment;
Fig. 11 is an isometric view of a valve bridge guide according to a fourth modification of the first principal embodiment;
Fig. 12 is an isometric view of a valve bridge and a valve bridge guide according to a fifth variant of the first principal embodiment;
Fig. 13 is an isometric view of a valve bridge guide according to a sixth modification of the first principal embodiment;
14 and 15 are isometric and sectional views of a valve bridge guide according to a seventh modification of the first principal embodiment, respectively;
Fig. 16 is an isometric view of a valve bridge guide according to an eighth modification of the first principal embodiment;
Fig. 17 is an isometric view of a valve bridge guide according to a ninth modification of the first principal embodiment;
18 to 21 are isometric, side and front views, respectively, of a valve bridge and a valve bridge guide according to a second main embodiment;
22 is a top isometric view of a valve bridge and a valve bridge guide according to a first variant of the second main embodiment;
23 is a cross-sectional view of a valve bridge according to the prior art;
Fig. 24 is a cross-sectional view of a valve bridge according to a third main embodiment;
25 is a sectional view of a valve bridge according to fourth to sixth main embodiments;
26 to 28 are a top view, an isometric view and a sectional view respectively of a valve bridge according to a seventh main embodiment;
Fig. 29 is a side view of a valve bridge according to an eighth main embodiment;
30 and 31 are isometric and sectional views respectively of a valve bridge and a bridge pin according to a ninth main embodiment;
32 is a partial cross-sectional side view of a valve actuation system according to the prior art;
33 is a top isometric view of a valve actuation system according to a tenth embodiment;
34 and 35 are respectively upper and lower isometric views of a valve bridge and a valve bridge guide according to an eleventh principal embodiment;
36 is a top isometric view of the valve bridge and valve bridge guide of FIGS. 34 and 35 disposed in a valve actuation system;

2-36 illustrate various embodiments of valve bridge systems incorporating valve bridge guides according to the present disclosure. In all embodiments and variations shown in FIGS. 2 to 36 , it is assumed that the valve bridge is of the type shown in FIG. 1 , ie the valve bridge has a locking mechanism of the general type shown in FIG. 1 and described above. do.

2 shows a first embodiment according to the present disclosure in which an internal combustion engine 202 includes a pair of valve bridges 204 and 212 for a single cylinder. In the illustrated embodiment, each valve bridge 204, 212 actuates two corresponding engine valves, but each valve bridge may 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) holds two engine valves of the same type, i.e., two intake valves or two exhaust valves; can make it work For convenience of explanation, only the features and operations of the first valve actuation system according to the first embodiment will be described, and it should be understood that the described features and operations are equally applicable to all valve bridges included in an internal combustion engine.

Thus, as shown, the first valve bridge 204 spans a pair of engine valves (not shown in FIG. 2) in a conventional manner known in the art. Each engine valve has a valve spring 208, 210 that biases its corresponding engine valve to a closed state (i.e., a state in which the engine valve head engages with a valve seat formed in the cylinder head 230) and a valve stem of the engine valve. It has valve spring retainers (209, 211) attached. As further shown, the valve bridge system 202 is directed downward from the valve bridge 204 and between the valve springs 208 and 210 (ie, in the direction of the cylinder head and away from the rocker arm 220). It further includes an extending valve bridge guide (206). In one embodiment, the distance that the valve bridge guide 206 extends between the valve springs 208 and 219 is minimally governed by the portion of the valve bridge 204 that surrounds the locking mechanism (eg, see FIG. 1). For reference, the depth of that portion of the valve bridge accommodates the outer plunger 720 and the outer plunger spring 746). In the embodiment shown in FIG. 2 , the valve bridge and the valve bridge guide form a unitary structure, i.e., a part of an undivided whole, so that the locking mechanism is provided with openings formed in the valve bridge 204 and the valve bridge guide 206 ( best shown in Figure 3). As will be 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 the valve spring retainers 209, 211 to control the valves. Prevent, minimize or at least counteract uncontrolled operation of the bridge 204.

FIG. 3 shows a cross-sectional view of the valve spring guide 206 and the first valve spring 208 along the cross-sectional line III-III (as shown in FIG. 2 ). An opening 310 for receiving the locking mechanism is formed in the valve spring guide 206 and FIG. 3 further shows the valve stem 320 disposed within the corresponding valve spring 208 . More specifically, FIG. 3 shows two valve bridge control surfaces 402 formed by valve bridge guides 206, which valve bridge control surfaces 402 are connected to corresponding valve springs 306 (only one shown in FIG. 3). ), i.e., the valve bridge control surface 402 is a concave surface relative to the convex outer surface of the valve springs 208 and 210. Although in accordance with this, the valve bridge control surface 402 is such that, during the controlled state of the valve bridge, the valve bridge control surface 402 (and consequently the valve bridge guide 206) rotates with its corresponding valve spring 208, 210. It is configured to avoid contact with The valve bridge control surface 402 is constructed to be as close as possible to the valve springs 208, 210 (within manufacturing tolerances) to ensure normal movement of the valve bridge 204, valve bridge guide 206, and valve springs 208, 210. and vibration may be 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 a compression spring such as valve springs 208 and 210 is deformed (ie, compressed), the outer diameter of the spring will increase slightly. Thus, the valve bridge control surface 402 can be configured to account for the maximum expected change in spring diameter while remaining as close as possible to the valve springs 208 and 210 .

In some instances, it may be undesirable for the valve bridge guide 206 to make contact with the valve springs 208, 210, otherwise premature degradation of the valve springs 208, 210 may result. Accordingly, it may be desirable to configure the valve bridge control surface 402 to contact the spring retainers 209 and 211 instead. To implement this configuration, it may be necessary to dimension the spring retainers 209, 211 to have an outer diameter larger than that of the valve springs 28, 210. In this case, the valve bridge control surface 402 is instead formed by the valve bridge guide 206 so that the valve bridge control surface 402 follows the corresponding spring retainers 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, this concave surface is configured to avoid contact of the valve bridge control surface 402 with the corresponding spring retainers 209, 211 during the controlled state of the valve bridge, and (within manufacturing tolerances) the valve spring 208 . ) may be insufficient to cause contact between

Although the various figures shown and described in this disclosure show at least two concave valve bridge control surfaces 402, this is not a requirement. For example, such a single valve bridge control surface 402 may be used when used in conjunction with other features that provide additional control of the otherwise uncontrolled movement of the valve bridge 204. For example, if the valve bridge 204 is equipped with bridge pins (see, eg, FIG. 21 , element 2102 ), a single valve bridge control surface 402 and bridge pin combination may suffice.

The configuration of the valve bridge control surface 402 according to the preferred embodiment is further described with reference to FIG. 4 which schematically shows the valve bridge guide 206 and valve spring 208 in an enlarged form. (Alternatively, as discussed above, the valve spring 208 shown in FIG. 4 may be considered a spring retainer, but only the valve spring 208 is described herein for ease of explanation.) , the valve bridge guide 206 includes a concave valve bridge control surface 402 proximate the outer diameter 408 of the valve spring 208. In practice, the clearance between the valve bridge control surface 402 and the outer diameter 408 is based in part on 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 tip in a receptacle formed in the valve bridge 204 to receive the engine valve tip. For example, if the valve bridge 204 moves ±0.25 mm, the gap between the valve spring 208 and the valve bridge control surface 402 must be greater than the tolerance of the parts plus the 0.25 mm play allowed. Additionally, the chamfer at the lower end of the valve bridge 204 ensures that the valve bridge 204 is still at the engine valve tip if the valve bridge 204 undergoes uncontrolled movement through the entire clearance to the valve spring or spring retainer. It must be large enough so that it can be repositioned on its own.

As further shown in FIG. 4 , the circumferential length of the concave valve bridge control surface 402 (relative to the outer diameter 408 of the spring 208 ) is defined by opposing edges 404 and 406 . In this preferred embodiment, the opposing edges 404 and 406 are lined with a line crossing the opposing edges 404 and 406 as shown when the valve bridge guide 206 is positioned during the controlled state of the valve bridge 204. 410 are at least spaced apart to form a secant to the outer diameter 408 of the valve spring 208 . When configured in this way, movement of the valve bridge guide 206 in either direction indicated by line 410 (eg, which may occur during an uncontrolled state of the valve bridge 204), if sufficiently large, causes a concave valve. It will be appreciated that by creating contact between the bridge control surface 402 and the outer diameter of the spring 408 the valve bridge guide 206 will generally bias away from the valve spring 208 and towards the other valve spring 210. . More generally, any rotational movement of the valve bridge 204 about the axis of the locking mechanism centerline is limited as well as lateral movement in both horizontal planes. With this in mind and referring back to FIGS. 2 and 3 , this actuation of the concave valve bridge control surface 402 during the uncontrolled state of the valve bridge 204 causes the valve bridge guide 206 to actuate the valve springs 208 , 210 . ) and themselves will tend to effectively dampen or even eliminate any uncontrolled movement of valve bridge 204 and valve bridge guide 206.

Referring now to FIGS. 5 and 6 , a first variant of the valve bridge guide 502 includes a monolith separate from the valve bridge 204 formed on the lateral sides of the valve bridge control surface 402 as shown. . Valve bridge 204 is also shown with receptacles 614 for receiving valve stem tips of engine valves, as known in the art and described above. In this embodiment (and the additional embodiments shown in FIGS. 7-13 ), the valve bridge guide 502 may be made of the same material (eg, steel) as the valve bridge 204, although in the preferred embodiment , the valve bridge guide 502 is formed of a stronger material that is softer than the valve bridge springs 208, 201 (or spring retainers 209, 211) but lighter in weight to prevent damage or breakage. For example, suitable mouldable polymers as known in the art may be used for this purpose. Another type of material from which to make the valve bridge guide will be apparent to those skilled in the art.

Nevertheless, as further shown, the valve bridge guide 502 defines an opening or bore 602 therein configured to suitably receive a portion 604 of the valve bridge 204 . As shown, portion 604 of valve bridge 204 received by valve bridge guide 502 preferably receives at least a portion of locking mechanism 606 . As further shown, in this embodiment, both valve bridge guide 502 and portion 604 of valve bridge 204 include fastener receiving features 504 and 608 . In this embodiment, the fastener receiving feature 504 of the valve bridge guide includes a bore that intersects an opening 602 formed in the valve bridge guide 502 . Thus, where the bore intersects the opening 602 , the fastener receiving feature 504 essentially comprises a channel having a semi-circular cross-section formed in the sidewall of the opening 602 . In a complementary manner, the fastener receiving feature 608 of portion 604 of valve bridge 204 is also formed as a semicircular channel in the outer sidewall surface of portion 604 . When aligned, each of these fastener receiving features 504, 608 may receive fasteners 610, 612 such that valve bridge guide 502 is operably connected to portion 604 of valve bridge 204. have. For example, in the illustrated embodiment, fasteners 612 may include split dowel pins as shown, although one skilled in the art will recognize that other types of fasteners, such as screws, may equally be used. In this way, the valve bridge guide 502 is relatively rigidly attached to the valve bridge 204 so that they move together. As an alternative to the fastener embodiment described above, the valve bridge guide 502 (or other embodiments of the valve bridge guide shown in FIGS. 7-13 ) may instead be constructed using a suitably strong and durable epoxy or similar adhesive for valves. It can be rigidly attached to the bridge 204. Furthermore, combinations of these techniques may be used depending on design choices.

Referring now to FIGS. 7 and 8 , a second variant of the valve bridge guide 702 comprises a monolith separate from the valve bridge 204 formed on the lateral sides of the valve bridge control surface 402 as shown. In this respect it is substantially similar to the valve bridge guide 502 of FIGS. 5 and 6 . However, in this embodiment, the valve bridge guide 702 extends inwardly from the sidewall surface of the opening 602 and is configured to engage a notch 804 formed in the outer wall surface of the portion 604 of the valve bridge 204. It includes the teeth 802 above. For example, notch 804 may include an annular groove or channel formed in the sidewall of portion 604 of valve bridge 204 . When the teeth 802 engage the notches 804, the valve bridge guide 702 can again actuate the valve bridge in a relatively rigid manner so that the valve bridge guide 702 and the valve bridge 204 move together. are connected In this embodiment, the placement of one or more of the teeth 802 and notches 804 may be equally reversed, i.e., the teeth 802 may be formed on the outer wall surface of the portion 604 of the valve bridge 204. It is to be noted that a notch 804 may be formed in the inner wall surface of the opening 602 .

As further shown in FIG. 7 , the valve bridge guide 702 can include at least two protruding members 704 and 706 that protrude from the valve bridge guide 702 toward the valve bridge 204 . As shown in FIG. 8 , the valve bridge 204 has a lower surface 806 , and in one embodiment the protruding members 704 and 706 extend past at least the lower surface 806 of the valve bridge 204 . In this embodiment, the at least two protruding members 704 and 706 assist in orienting the valve bridge guide 702 on the valve bridge 204, preventing rotation of the valve bridge 204 relative to the valve bridge guide 702. do. In this way, the at least two protruding members 704, 706 further assist in the alignment of the valve springs 208, 210 or spring retainers 209, 211 and the valve bridge control surface(s) 402.

Referring now to FIGS. 9 and 10 , the valve bridge guide 902 is formed as a unitary body separate from the valve bridge 204 formed on the lateral side of which the valve bridge control surface 402 is formed as shown ( A third variant of 902) is shown. However, in this embodiment, the valve bridge guide 902 has a side opening 904 with a cantilevered latch or catch 906 disposed therein. As shown, the catch 906 is configured to mate with a corresponding notch 1002 formed in the outer wall surface of portion 604 of valve bridge 204 . For example, again, notch 1002 may include an annular groove or channel formed in a sidewall of portion 604 of valve bridge 204 . When the catch 906 engages the notch 804, the valve bridge guide 702 is again actuable to the valve bridge in a relatively rigid manner so that the valve bridge guide 902 and the valve bridge 204 move together. Connected. As shown, the valve bridge guide 902 may further include a secondary latching surface 908 configured to mate with a corresponding secondary notch 1004 formed in a portion 604 of the valve bridge 204 . By providing multiple latching pairs 906, 1002/908, 1004, the stability of the valve bridge guide 902 relative to the valve bridge 204 may be improved.

Referring now to FIG. 11 , a fourth variant of the valve bridge guide 1102 is shown. In this variation, the valve bridge guide 1102 is monolithic, disposed between the spring retainers 209 and 211 and the valve bridge 204 . Notches 1104 and 1106 are provided to position the valve bridge guide 1102 against the tip of the engine valve. Additionally, a central opening 1107 may be provided so that a portion of the valve bridge 204 (eg, that portion housing a locking mechanism as shown in FIG. 1 ) extends through the valve guide 1102 . Similar to the embodiment of FIGS. 7 and 8 , the valve bridge guide 1102 has at least two in the form of sidewalls 1108 and 1110 which in turn form a channel 1116 configured to receive the valve bridge 204 . Includes two protruding members. In this embodiment, the inner surfaces 1112, 1114 of the sidewalls 1108, 1110 that rise above the valve bridge 204 are the sides of the valve bridge 204 as may occur during an uncontrolled state of the valve bridge 204. Serves as a valve bridge control surface to prevent directional movement or rotation. Additionally, although not shown in FIG. 11 , 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. can Any portion of the valve bridge 204 (eg, at an engine valve tip) to the extent that the valve bridge guide 1102 is rigidly attached to the valve bridge 204 (using any of the techniques described above). Excessive lift will cause a similar lift of the valve bridge guide 1102, which in turn resists uncontrolled movement and causes the valve bridge 204 to settle back to the engine valve tip yet again.

Referring now to FIG. 12 , a fifth variant of the valve bridge guide 1202 is shown in that the valve bridge control surface 402 comprises a monolith separate from the valve bridge 204 formed on the lateral sides, as shown. It is substantially similar to the valve bridge guide 502 of FIGS. 5 and 6 . As further shown and similar to the second variant shown in FIGS. 7 and 8 , this embodiment of the valve bridge guide 1202 has a plurality of projections extending upwardly from the main body of the valve bridge guide 1202 . It further includes members 1204-1212, which serve similar purposes as described above. Additionally, as shown, each of the protruding members 1204-1212 has an attachment surface 1214, 1216 in the form of an inwardly extending finger 1214, 1216 disposed at a distal end of the protruding member 1204-1212 (FIG. 12 only two are shown). The attachment surface thus formed is configured to mate with a corresponding surface 1220 of the valve bridge 204 , in this case a top surface of the valve bridge 204 . In this way, the valve bridge guide 1202 remains on the valve bridge 204. Alternatively and similarly to the embodiment of FIGS. 9 and 10 , fingers 1214 and 1216 may instead engage notches or similar features formed on the lateral sides of valve bridge 204 .

Figure 13 shows a sixth variant of the first embodiment in which the valve bridge guide 1302 is formed from two guide elements 1304 and 1306 configured to engage opposite sides of the valve bridge. As in other embodiments, each of the guide elements 1304 and 1306 defines a valve bridge control surface 402 as described above. Additionally, each of the guide elements 1304 and 1306 defines a first opening 1308 (only one shown) configured to receive a portion 604 of a valve bridge 204 (not shown). As further shown, each of the guide elements 1304 and 1306 is also configured to receive one of the arms of the valve bridge 204 (ie, that portion of the valve bridge that extends from the center of the valve bridge to one of the engine valves). A configured channel or second opening 1310 is included. Further, each of the guide elements 1304 and 1306 includes fasteners in the form of complementary first latches 1312 and first latch notches 1314 and second latches 1316 and second latch notches 1318. Thus, the guide members 1304 and 1306 can be firmly connected to each other. Alternatively, any of the attachment mechanisms described above (dowel pins, epoxies, etc.) may be used as "fasteners" for this purpose. When connected, the guide elements 1304 and 1306 define a valve bridge guide 1302 that is held in place relative to the valve bridge 204 by the fact that the second opening 1310 surrounds the arm of the valve bridge 204. form as a whole.

14 and 15 show a seventh variant of the first principal embodiment in which the valve bridge guide 1402 is formed as a stamped sheet metal structure having a horizontal surface 1404 and a continuous sidewall 1406 extending downwardly therefrom; have. In this variation, and similar to the embodiment shown in FIG. 11 , the valve bridge guide 1402 is configured to rest on top of the spring retainers 209, 211 ( FIG. 15 ) and below the valve bridge 204 (not shown). designed In FIG. 15 , sidewalls 1406 are shown extending past spring retainers 209 and 211 as well as initial portions of valve springs 208 and 210 . In one embodiment, the extent of the sidewall 1406 is such that the valve bridge guide 1402 cannot fully lift off the spring retainers 209, 211 despite any vertical displacement applied to the valve bridge 204. Besides the central opening 1406 through which a portion of the valve bridge 204 passes, the valve bridge guide 1402 includes a plurality of protruding members 1408 - 1416 similar to those shown in FIGS. 7, 8, 11 and 12 ( four are shown in the example shown). As shown, protruding members 1408 - 1416 are formed as upward bends of horizontal surface 1404 , resulting in openings 1426 and 1428 through which the tip of engine valve 1502 passes. In this case, protruding members 1408 - 1416 again form valve bridge control surfaces 1422 and 1424 to resist uncontrolled movement of valve bridge 204 .

16 is an eighth variation of the first principal embodiment in which the valve bridge guide 1602 includes two guide elements 1603 (only one shown) configured to engage opposite sides of a valve bridge 204 (not shown). An isometric view is shown. Each guide member 1603 is formed as a stamped sheet metal structure having a horizontal surface 1604 and a continuous sidewall 1606 extending downwardly therefrom, similar to the embodiment of FIGS. It is configured to rest only on top. Again, each guide member 1603 includes a plurality of upwardly extending protruding members 1608 and 1610 and a central opening 1612 for the passage of an engine valve tip, each of the protruding members 1608 and 1610 having Forms a valve bridge control surface 1614 to resist uncontrolled movement of the valve bridge 204.

Similar to the embodiment of FIG. 16 , the embodiment shown in FIG. 17 includes a valve bridge guide 1702 comprising a pair of guide elements 1703 configured to rest on separate spring retainers 209 and 211 . . In this case, each guide element 1703 formed of a moldable polymer includes a horizontal surface 1704 and a continuous sidewall 1706 extending downwardly therefrom, similar to the embodiment of FIGS. 14 and 15 , but the embodiment of FIG. 16 As in, it is configured to rest only on a single spring retainer 209. Again, each guide member 1603 includes a plurality of upwardly extending protruding members 1708 and 1710 and a central opening 1712 for passage of an engine valve tip, each of the protruding members 1708 and 1710 having Forms a valve bridge control surface 1614 to resist uncontrolled movement of the valve bridge 204. However, in this case, each guide element 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 follow the outer surface of the valve springs 208, 210, but extends downward between the valve springs 208, 210 and is shown in FIG. It is configured to follow that portion of the valve bridge 204 that houses the locking mechanism as described above.

Referring now to FIGS. 18-21 , there is shown a second primary embodiment in accordance with the present disclosure in which 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 again each valve bridge may 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 that biases the corresponding engine valve to a closed state and a valve spring retainer 209, 211 attached to the valve stem of the engine valve. As best seen in FIG. 19 , the valve bridge 204 includes a lower surface 1902 facing the engine valve and an upper surface 1904 opposite the lower surface 1902 .

As further shown in this second main embodiment, the valve bridge system further comprises a valve bridge guide in the form of a first member 1802 having a first surface 1906 opposing the upper surface of the valve bridge 204. do. Using suitable fasteners 1806 (eg, bolts that are screwed into a cylinder head or similar fastening 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 at a predetermined distance 1908 from the upper surface of the valve bridge 204 when at least two valve bridges are held in a closed state. Additionally, as shown, the first fixed position of the first member 1802 is aligned with the first of the at least two engine valves, the first engine valve being furthest from the rocker shaft 1808 of the internal combustion engine 202. far away As shown, the first member 1802 can be configured to align with the first engine valve for more than one valve bridge 204, 212 as described. Further, the first member 1802 may also in this regard extend across the valve bridge for multiple cylinders of an internal combustion engine, or multiple such cylinders where the configuration of the cylinders avoids the use of a single first member 1802. A first member 1802 may be included.

In this embodiment, the distance 1908 between the first member 1802 and the upper surface 1904 of the valve bridge 204 is the first when the valve bridge 204 is in a controlled state for at least two engine valves. sufficient to prevent contact between the first surface 1906 of the member 1802 and the top surface 1904 of the valve bridge 204 and when the valve bridge 204 is in an uncontrolled state for at least two engine valves. It is preferably sufficient to enable contact between the first surface 1906 and the top surface 1904 to resist uncontrolled movement of the bridge 204 . As used herein, uncontrolled movement of the valve bridge 204 is resisted to the extent that it opposes movement of the valve bridge outside its normal range of movement when any of the disclosed valve bridges are operated in a controlled state. Thus, while many of the variations of the first embodiment shown in FIGS. 2-12 oppose movement that would result in tilting or rotation of the valve bridge 204 relative to the engine valves, the first member 1802 is specifically adapted to the engine valves. To prevent complete separation of the valve bridge 204 from the valve, excessive vertical displacement of the valve bridge 204 relative to the engine valve is counteracted. By forming a distance 1908 relative to the closed position of the engine valve, contact between the valve bridge 204 and the first member 1802 is prevented during controlled actuation of the valve bridge 204 . However, by further forming the desired distance 1908 to be sufficiently small nevertheless, the desired resistance to uncontrolled movement of the valve bridge 204 may be provided. In one embodiment, the predetermined distance 1908 may be based on the depth 2002 of the receptacle 2004 provided by the valve bridge 204, 212 to mate with the valve tip 2006 of the engine valve (FIG. 20). . In particular, the predetermined distance 1908 may be selected to be less than the depth 2002 of the receptacle 2004. In this way, the valve bridge 204, 212, when actuated in an uncontrolled state, first moves a distance before the valve bridge 204, 212 can travel a distance exceeding the depth 2002 of the receptacle 2004. It will contact member 1802, which would otherwise cause separation of valve bridges 204 and 212 from valve tip 2006. It is also known that in some types of engine brakes only actuate a single inboard engine valve (i.e., closest to the rocker shaft), thereby interlocking the valve with the outboard engine valve (i.e., furthest from the rocker shaft). That portion of the bridge may be raised slightly upwards, for example by about 1 to 2 mm. Accordingly, the predetermined distance 1908 should be chosen to accommodate this possibility to avoid unwanted contact with the valve bridge 204. Additionally, normal wear of engine valve seats can cause upward lift of engine valve tips over time, and the distance 1908 should also account for this possibility.

In this second embodiment, the valve bridge guide is held in a second fixed position relative to the valve bridge 204 and has a second member ( 1910 ) facing the upper surface 1904 of the valve bridge 204 1804) may be further included. As with the first member 1802, the second surface 1910 is maintained at a distance 1908 from the top surface 1904 for the same reasons as described above. In one embodiment, the second fixed position of the second member 1804 is aligned with the second engine valve of the at least two engine valves, the second engine valve being closest to the rocker shaft 1808 . Also, as best shown in FIGS. 18 and 19 , the second member 1804 may be formed in a unitary structure together with the rocker pedestal 1810 . In this way, the first and second members 1802, 1808 can be individually aligned with the different engine valves at the same predetermined distance 1908 from the top surface 1904, providing uniform resistance to uncontrolled movement. It serves as a valve bridge guide to provide

As is known in the art, some valve actuation systems include a valve train and a source of auxiliary motion that provides auxiliary motion to a single engine valve despite the presence of valve bridge 212 . This is accomplished through the use of a bridge pin 2102 that allows auxiliary valve actuation actions to be applied to a single engine valve and main valve actuation actions to be applied to a single engine valve via valve bridge 212 as is known in the art. In this case, the existence of the bridge pin 712 passing through the valve bridge 212 effectively serves as a second member forming the valve bridge guide. That is, when the valve bridge 212 is operated in an uncontrolled state, the presence of the bridge pin 712 (operably connected to both the auxiliary rocker arm 2104 and the single engine valve) bridges the valve bridge 212. It will act to limit sliding motion relative to the pin 712 only. In this case, the presence of the auxiliary rocker arm 2104 (or other auxiliary valve train component) will actuate to prevent the valve bridge 212 from moving on the bridge pin 2102. Again, if a first member 1802 is present (as shown), the joint actuation of the first and second members will resist uncontrolled movement of the valve bridge 212, particularly upward movement. .

Figure 22 shows a first variant of the second embodiment in which the valve bridge guide includes a first member 2202 formed as a three-sided "strap". Like the embodiment of FIGS. 18-21 , the variation shown in FIG. 22 is actuated to resist uncontrolled movement by placing the first member 2202 in a position in contact with the top surface 1904 of the valve bridge. In this embodiment, first member 2202 has two substantially vertical elongated sides 2204 (one of which is shown in FIG. shown), each of elongated side 2204 is mounted to cylinder head 230 . A third substantially horizontal side ( 2206 connects the first and second elongated sides 2204. As in the embodiment of FIGS. 18-21 , the third side 2206 is held in a fixed position a distance 1908 away from the top surface 1904 (not shown in FIG. 22 ). As further shown, the third side 2206 is a portion of the valve bridge 214 (e.g., referring to FIG. 1, the outer plunger 720/cap 730) is the rocker arm as shown. and an opening 2210 brought into contact with 2212. In this variation, displacement of the valve bridge 204 is limited by the third side 2206 of the first member 2202 and the opening 2206 formed therein.

23 is a cross-sectional view of a valve bridge illustrating the disadvantages of prior art systems. In particular, FIG. 23 shows a valve bridge with a valve bridge body 2302 spanning two engine valve stems 2304 and 2306 . 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. The bridge pin 2308 is then received in a through bore 2310 formed in the valve bridge body 2302 and aligned with the first engine valve 2306, bringing the bridge pin 2308 into contact with the secondary rocker arm 2312. let it The valve bridge body 2302 also includes a receptacle 2314 aligned with the second engine valve 2304 and configured to receive the stem of the second engine valve 2304 . In FIG. 23 , valve bridge 2302 is in an uncontrolled state as shown by receptacle 2314 losing contact with second engine valve 2304 . This is due to the fact that no surface is provided to restrain upward movement of the valve bridge 2302 during uncontrolled conditions.

FIG. 24 shows a valve bridge according to a third main embodiment in which a valve bridge substantially similar to that shown in FIG. 23 is shown. However, in this case, the valve bridge also includes a bridge pin boss 2402 having a through bore 2404 formed therein and having a greater longitudinal length (or height) compared to the embodiment shown in FIG. 23 . . As a result, the upper surface 2406 of the bridge pin boss 2402 is closer to the lower surface 2408 of the secondary rocker arm 2312 (eg, the lower surface of the actuator in the illustrated embodiment). Thus, when the valve bridge is in an uncontrolled condition that results in upward movement of the valve bridge body 2302, the top surface 2406 of the bridge pin boss 2402 completely disengages the valve bridge body 2302 from the valve stem. will contact the lower surface 2408 of the secondary rocker arm 2312 before it has the potential to become. This is shown in FIG. 24 where contact between upper surface 2406 and lower surface 2408 prevents complete separation of receptacle 2410 from the stem of second engine valve 2304 .

It is also understood that a similar upper surface of that portion of the valve bridge body 2302 aligned with the main rocker arm 2412 can also be configured in a similar manner 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 is such that the upper surface 2411 of the valve bridge body 2302 maintains the main rocker arm during uncontrolled movement of the valve bridge body 2302. 2412) (e.g., the lower surface of the swivel pit in the illustrated embodiment). However, in this case, the height of the upper surface 2411 should be chosen so as not to interfere with the ability of the collapse mechanism 2412 to completely absorb any valve actuation provided by the main rocker arm 2412. That is, the top surface 2411 is in 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. It should not increase to a point.

Referring now to FIG. 25 , there is shown a valve bridge according to fourth to sixth main embodiments. In particular, FIG. 25 once again shows a valve bridge similar in construction to the valve bridge shown in FIG. 23 . A fourth primary embodiment relates to the characterization of the gap between the inner diameter of the through bore 2502 and the outer diameter of the bridge pin 2504. In particular, by tightly controlling and minimizing the clearance between the through-bore and the bridge pin, the occurrence of uncontrolled movement will result in “pinching” (or jamming) of the valve bridge body 2302 and bridge pin 2504. 25 by the contact point 2505 between the through bore 2502 and the bridge pin 2504. This pinching, in turn, dampens any further movement of the valve bridge body 2302, which tends to keep the valve bridge body 2302 aligned with the engine valves.

25 further illustrates to the extent that the fifth main embodiment shows an increased-radius spring retainer 2506 (relative to the radius of a conventional spring retainer 2510, ie, relative to the radius of a valve spring (not shown)). do. In this embodiment, the increased-radius spring retainer 2506 prevents uncontrolled movement (specifically, rotation of the valve bridge body 2302) of the portion 2508 of the valve bridge body 2302 that extends between the engine valve stems. while making quicker contact 2511 with the increased-radius spring retainer 2506 to resist further rotation of the valve bridge body 2302.

Still, FIG. 25 further illustrates a sixth main embodiment in terms of showing an extended valve stem feature. In the illustrated embodiment, the elongated valve stem feature takes the form of a bridge pin 2512 present in the second through bore 2518. As shown, bridge pin 2512 is free to move up and down on engine valve stem 2514. In this case, when the valve bridge body 2302 is in an uncontrolled state, the bridge pin 2512 is free to move upward with the valve bridge body 2302. As long as the bridge pin 2512 remains seated on the engine valve stem 2514, despite uncontrolled movement of the bridge pin 2512 and the valve bridge body 2302, the bridge pin 2512 will move the valve bridge Keep body 2302 aligned with engine valve stems 2514 and 2516. The same principle of controlled movement of the engine valve stem 2516 can equally apply to the bridge pin 2504 aligned with the auxiliary rocker arm, as shown. In this embodiment, either or both of the engine valve stems 2514, 2516 extend over the spring retainers 2506, 2512 up to 10 mm, for example, compared to the more typical length of 2-3 mm. length may be desirable.

26 to 28 show a valve bridge according to a seventh main embodiment. According to a typical valve bridge, the valve bridge shown includes a valve bridge body 2602 spanning at least two engine valves 2604 and 2606. In this embodiment, slots 2608 are formed in those portions of valve bridge body 2602 configured to contact the stems of engine valves 2604 and 2606. In particular, as best seen in FIG. 28 , slot 2608 extends laterally transversely intersecting longitudinal axis 2806 of receptacle 2802 and engine valve stem 2604 (only one shown in FIG. 28 ). Can contain slots. 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 aligns 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 slot 2608 and the C-clip 2702 may occur, for example, during uncontrolled movement of the valve bridge body 2602, the C-clip 2702. to resist separation of the engine valve stem 2604 from the receptacle 2802. Although a slot 2608 is shown in FIGS. 26-28 as extending laterally from the valve bridge body 2602, this is not a requirement. For example, slot 2608 could instead extend perpendicularly from the plane of FIG. 28 , that is, perpendicular to the longitudinal axis of the valve bridge body and perpendicular to the longitudinal axis 2806 of engine valve stems 2604 and 2606 . .

29 is a side view of a valve bridge according to an eighth main embodiment. In this embodiment, the valve bridge body 2902 includes a protrusion 2904 that extends downward from a lower surface 2908 of the valve body 2902 and is located between at least two engine valve stems (not shown). As further shown, the protrusion 2904 is directed towards and down the at least one spring retainer 2910 such that the hook or latching feature 2906 extends beyond the periphery of the at least one spring retainer 2910 ( and at least one hook feature 2906 (only one shown) extending away from 2904. When the valve bridge body 2902 is in an uncontrolled state, the hook feature 2906 contacts the underside 2912 of the valve spring retainer 2910, to the point where the valve bridge body is completely separated from the engine valve stem. It will prevent the valve bridge body 2902 from separating from the engine valve stem. As with the fifth embodiment described above with respect to FIG. 25 , the increased-radius spring retainer 2910 can provide a protruding rim of material that extends beyond the outer circumference of the corresponding valve spring 2914 . In this way, hook feature 2906 may engage spring retainer 2910 to better ensure resistance to valve bridge separation.

As further shown in FIG. 29 , the peripheral shape 2914 of the protrusion 2904 is such that the valve bridge body 2902 is positioned on one of the engine valves (as shown in FIG. 29 , in the case of an auxiliary valve actuation operation). Likewise, it moves downward (to the far right) and is configured to tilt without contacting the springs 2914 and 2918. Based on the configuration shown, installation of the valve bridge is facilitated by first installing the left side and then rotating the valve bridge downward over the rightmost engine valve stem (and corresponding bridge pin 2920). While held down by a separate auxiliary rocker or integrated actuator piston (not shown), the bridge cannot be removed due to the latching effect of the hook feature 2906.

30 and 31 show a valve bridge and a bridge pin according to a ninth main embodiment. In this embodiment, valve bridge body 3002 receives corresponding bridge pins 3008 and 3010 between respective arms 3022 and 3024 formed by slots 3004 and 3006 extending into valve body 3002. and open, lateral extension slots 3004 and 3006 configured to As best seen in FIG. 31 , each bridge pin 3008, 3010 has a receptacle 3102 formed therein and configured to receive a corresponding engine valve stem 3012. As shown, each bridge pin 3008, 3010 has a spool-like shape that includes a barrel body 3016 and an increased-diameter end cap 3018, 3020 (relative to the barrel body 3016). The slots 3004 and 3006 are configured to keep the arms 3022 and 3024 relatively close clearance to the barrel body 3016 of the respective bridge pins 3008 and 3010. Meanwhile, slots 3004 and 3006 are configured so that arms 3022 and 3024 contact end caps 3018 and 3020. In this way, vertical movement of the bridge pins 3008 and 3010 results in a gap 3104 between the upper (and/or lower) surfaces of the arms 3022 and 3024 and the complementary surfaces formed by the end caps 3018 and 3020. limited by In this way, if the valve bridge body 3002 experiences uncontrolled movement, the constraint applied to the valve bridge body 3002 by the bridge pins 3008 and 3010 will cause separation from the engine valve stems 3012 and 3014. prevent. 24, the upper surface 3026 of the valve bridge body 3002 is such that the gap between the upper surface 3026 and the end cap 3010 is upward of the valve bridge body 3002. Note that it may be configured to further restrict movement.

32 shows a valve actuation system according to the prior art. In particular, valve actuation systems are known in which a collapse mechanism similar to that shown in FIG. 1 is disposed on the rocker arm 3202 or pushrod 3204 rather than the valve bridge 3206 as shown in many of the previously described embodiments. . As is known in the art, rocker arm 3202 meshes well with rocker shaft 3208, but such a valve actuation system will cause valve bridge 3206 to enter an uncontrolled state if excessive lash builds up in the valve train. present an opportunity to For example, a sudden collapse in pushrod 3204 can cause the rocker to rotate backwards (i.e., toward pushrod 3204) equal to the sudden removed valve lift. Thus, if the lost valve lift is relatively high (e.g., 14 mm in some systems), a sudden rearward rotation of the rocker arm 3202 may cause the rocker arm 3202 to strike the valve cover 3210 or other object. . Because the rocker arm 3202 is generally relied upon to keep the valve bridge 3206 engaged with the engine valve stem, sudden movement of the rocker arm 3202 combined with the rapid acceleration of the valve bridge 3206 under the influence of the valve spring Backward rotation can cause the valve bridge to move in an uncontrolled manner, resulting in disengagement.

To prevent the valve bridge 3206 from separating in this situation, a stop may be provided to prevent excessive rotation of the rocker arm 3202 allowing the valve bridge 3206 to escape. An example of this is illustrated in FIG. 33 where a rigid or fixed block 3302 is positioned to prevent rearward over-rotation of the rocker arm 3202. In the illustrated embodiment, the stationary block 3302 is rigidly attached to the rocker shaft 3208, in this example, uprights 3304 configured to engage the surface of the rocker arm 3202 to prevent over-rotation thereof; and Includes all horizontal (3306) surfaces. The fixation block 3302 is configured so that the vertical and horizontal surfaces 3304 and 3306 do not (ie, in a controlled state) interfere with the normal travel of the rocker arm 3202. However, the anchor block 3302 is also configured such that the vertical and horizontal surfaces 3304 and 3306 are positioned to prevent over-rotation of the rocker arm 3202.

For example, the illustrated rocker arm 3202 can, in this case, include a rear surface 3308 formed by a control valve boss formed on the rocker arm 3202. In the event of a sudden rearward rotation, rear surface 3308 will contact vertical surface 3304 to prevent over-rotation of rocker arm 3202. Similarly, the rocker arm further includes an upward surface 3310. In the event of a sudden rearward rotation, rear surface 3310 will contact horizontal surface 3306 to prevent over-rotation of rocker arm 3202. Although the illustrated embodiment includes both vertical and horizontal surfaces 3304 and 3306, this is a requirement since it is contemplated that either of these surfaces may be sufficient to prevent overrotation depending on the configuration of rocker arm 3202. not.

34 and 35 show a valve bridge and a valve bridge guide according to an eleventh embodiment. In this embodiment, a valve bridge guide 3404 is provided that is attached to (or integrally formed with) the valve bridge body 3402. As shown, a valve bridge guide 3404 is disposed on a side of the valve bridge body 3402 that is not intended to mate with an engine valve (not shown) that may also be actuated by an auxiliary motion source. In the illustrated embodiment, the valve bridge guide 3404 is a half-cylinder wall configured to be attached to the lower surface 3502 of the valve bridge body 3402 such that the half-cylinder wall extends downwardly from the lower surface 3502. is shaped However, as shown, as long as the half-cylinder wall extends downwardly below the lower surface 3502, the valve bridge guide 3404 may not rest on some other surface (eg, upper surface) of the valve bridge body 3402. It is understood that it can be attached.

36 shows the valve bridge and valve bridge guide of FIGS. 34 and 35 disposed in a valve actuation system; As shown, valve bridge body 3402 spans two engine valve stems and valve bridge guide 3404 includes an outer lateral portion of valve spring retainer 3602. The radius of the half-cylinder wall (preferably about or near the longitudinal axis of the corresponding engine valve stem) is such that, during normal (i.e., controlled) operation of the valve bridge, the half-cylinder wall and the valve spring retainer ( 3602) or the corresponding valve spring 3604 so that no contact is made. On the other hand, the radius of the half-cylinder wall is additionally such that during an uncontrolled state of the valve bridge body 3402, the half-cylinder wall contacts the valve spring retainer 3602 but avoids contact with the valve spring 3604. It consists of As with the embodiments described above with respect to FIGS. 25 and 29 , the increased-radius spring retainer further provides contact between the valve spring retainer 3602 and the spring retainer (and, preferably, not the valve spring 3604 ). It can be used to ensure well.

As noted above, the present disclosure describes various embodiments and variations of valve bridge guides that can be used to resist, ie prevent, minimize or counter uncontrolled movement of the valve bridge. Although various features have been described in connection with specific embodiments, those skilled in the art will appreciate that various of these features may 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 comprising at least two engine valves, a first engine valve of the at least two engine valves being connected by an auxiliary rocker arm via a bridge pin. Operated, the valve bridge:
a through-bore configured to extend between at least two engine valves, align with the first engine valve, and include a through-bore configured to receive the bridge pin, align with a second engine valve of the at least two engine valves, and include a through bore configured to receive the bridge pin. a valve bridge body further comprising a receptacle configured to receive a stem of an engine valve; and
a bridge pin boss having a through bore formed therein, having a longitudinal length and terminating at an upper surface, wherein the bridge pin boss when the valve bridge is in an uncontrolled state for the at least two engine valves; wherein the longitudinal length is configured such that the upper surface of the is in contact with the surface of the auxiliary rocker arm to resist uncontrolled movement of the valve bridge.

Images