Multi-valve activating valve bridge

Abstract

Multi-valve activating valve bridge (200) for an engine (100) with a rocker arm engaging tappet head (202), at least two arms (204, 206) extending transversely to the rocker arm and engaging the tappet head (202), and a valve stem guide pocket (208, 210) provided on each of the arms (204, 206), at least one of the valve stem guide pockets (208, 210) having: a valve stem contact surface (212), a tapered surface (216) extending from the valve stem contact surface (212) toward an opening (214) of the valve stem guide pocket (208, 210), the tapered surface (216) defining an inverted frustoconical cavity, and a first inner diameter (D1) of the valve stem guide pocket (208, 210) at the valve stem contact surface (212) which is greater than a second inner diameter (D2) of the valve stem guide pocket (208, 210) at the opening (214).

Description

Technical area

[0001] The present disclosure relates to a valve activation arrangement for an internal combustion engine and, in particular, to a multi-valve activating valve bridge. background

[0002] The simultaneous activation of a pair of valves associated with a cylinder in an internal combustion engine is typically accomplished with a valve bridge. The valve bridge is activated using a rocker arm to contact terminal ends of valve stems associated with the valves to effect valve operation between an open and closed position. In situations of temporary valve sticking, temporary piston-to-valve contact, valve train separation from dynamic operation, or any other similar situation that may interfere with simultaneous movement of the valves, the load distribution on the valve bridge may be uneven. This can result in the application of unequal forces and stresses to the valve bridge and valves, potentially leading to unnecessary damage or breakage of the valve bridge and valves.

[0003] A valve deactivation device for internal combustion engines is known from DE 11 2011 100 745 T5.

[0004] DE 10 2006 019 254 A1 describes a device for actuating several gas exchange valves.

[0005] US 5 699 762 A discloses a valve actuation system for internal combustion engines.

[0006] US 2006 / 0 260 572 A1 describes an electromagnetically operated valve.

[0007] US 4,922,867 A relates to a valve activation mechanism for an internal combustion engine and includes an integrally formed stop element for limiting the axial travel of the valves toward the piston to a predetermined maximum extent in the event that an adjacent associated valve becomes stuck and immobile. The present invention further discloses a valve activation mechanism with a guideless valve bridge having specially designed contact surfaces that prevents both excess axial movement of the valve stem and the transmission of unwanted loads to the valve stem or adjacent structures. Summary of Revelation

[0008] In one aspect of the present disclosure, a multi-valve-activating valve bridge for an engine is provided. The valve bridge includes a rocker arm-engaging tappet head and at least two arms extending transversely of the rocker arm and engaging the tappet head. The valve bridge further includes a valve stem guide pocket provided on each of the arms. At least one of the valve stem guide pockets has a valve stem contact surface and a tapered surface extending from the valve stem contact surface toward an opening of the valve stem guide pocket. The tapered surface defines an inverted frustoconical cavity. A first inner diameter of the valve stem guide pocket at the valve stem contact surface is greater than a second inner diameter of the valve stem guide pocket at the opening.

[0009] In another aspect, a multi-valve-activating valve activation assembly for an engine is provided. The multi-valve-activating valve activation assembly includes a rocker arm and a multi-valve-activating valve bridge. The valve bridge includes a rocker arm-engaging tappet head and at least two arms extending transversely of the rocker arm and engaging the tappet head. The valve bridge further includes a valve stem guide pocket provided on each of the arms. At least one of the valve stem guide pockets includes a valve stem contact surface and a tapered surface extending from the valve stem contact surface toward an opening of the valve stem guide pocket. The tapered surface defines an inverted frustoconical cavity.A first inner diameter of the valve stem guide pocket at the valve stem contact surface is larger than a second inner diameter of the valve stem guide pocket at the opening.

[0010] Other features and aspects of the disclosure will become apparent from the following description and the following drawings. Short description of the drawings Fig. 1 illustrates an exemplary combustion engine, Fig. 2 illustrates a perspective view of a multi-valve activating valve bridge according to one aspect of the present disclosure, Fig. 3 illustrates a cross-sectional view of a multi-valve activating valve bridge of the Fig. 2, Fig. 4 illustrates a cross-sectional view of the multi-valve activating valve bridge according to an alternative embodiment of the present disclosure, Fig. 5 illustrates a schematic view of the multi-valve activating valve bridge in a straight position, according to yet another embodiment of the present disclosure, Fig. 6 illustrates a schematic view of the multi-valve activating valve bridge in a straight position, Fig. Figure 7 illustrates a schematic view of the multi-valve activating valve bridge in a first inclined position and Fig. Figure 8 illustrates a schematic view of the multi-valve activating valve bridge in a second inclined position. Detailed description

[0011] The present disclosure relates to a multi-valve activator valve bridge for an internal combustion engine. Fig. 1 illustrates an exemplary internal combustion engine 100, hereinafter referred to as engine 100. The engine 100 may be any type of engine (combustion, gas, diesel, gaseous fuel, natural gas, or propane-based engine, etc.), of any size, with any number of cylinders, and in any configuration (“V,” inline, radial, etc.). The engine 100 may be used to power any machine or other device, including on-highway trucks or vehicles, off-highway trucks or machines, earthmoving equipment, generators, aeronautical applications, locomotive applications, marine applications, pumps, stationary equipment, and other engine-driven applications.

[0012] In one aspect of the present disclosure, the engine may be a compression-ignition internal combustion engine, such as a diesel engine. For clarity, the following description refers to a single-cylinder engine, but the principle of the present disclosure can easily be applied to a multi-cylinder engine. The engine 100 includes a cylinder block 102 and a cylinder head 104 attached to the cylinder block 102. In the Fig. In the exemplary embodiment shown in Figure 1, the engine 100 may include a piston 106 configured to reciprocate within a cylinder 108 defined in the cylinder block 102. The piston 106 is connected to a crankshaft 110 via a connecting rod 112. The engine 100 may include a valve train 114. The valve train 114 may include one or more valves 116, such as a fuel injector, intake valves, and exhaust valves, disposed within the cylinder head 104. The valves 116 are operable between an open position and a closed position.

[0013] The valve train 114 further includes a valve activation assembly 118. In an exemplary embodiment, the valve activation assembly 118 includes a camshaft 120 having a cam 122 for pushing against a pushrod 124 and configured to translate the rotational movement of the camshaft 120 into linear movement of the valves 116 via a rocker arm assembly 126 and a valve bridge 200. In the illustrated embodiment, the rocker arm assembly 120 is rotatably mounted on the cylinder head 104 about a pivot point and engages the valve bridge 200. In one aspect of the present disclosure, the valve bridge 200 is a multi-valve-activating valve bridge 200. As those skilled in the art will appreciate, the valve bridge 200 is shown as associated with two valves 116, however, the valve bridge 200 may be associated with any number of valves without departing from the spirit of the present disclosure.

[0014] Furthermore, the valve bridge 200 may be connected to each of the valves 116 by a pair of valve stems 128. A valve spring 129 may be disposed around each valve stem 128 between the cylinder head 104 and the valve bridge 200. The valve spring 129 may be configured to bias the valves 116 into engagement with corresponding valve seats to close fuel inlets and / or exhaust outlets.

[0015] Fig. 2 illustrates an exemplary multi-valve activating valve bridge 200 according to one aspect of the present disclosure. Fig. Figure 3 illustrates a sectional view of the valve bridge 200 along an axis II' of the Fig. 2. In one aspect of the present disclosure, the valve bridge 200 may be a floating-type valve bridge that is unconstrained and floats, thereby causing its reorientation in response to unequal valve opening displacements when there is unequal displacement of the valves 116. In an alternative aspect of the present disclosure, the valve bridge 200 may be a guided-type valve bridge that remains guided and / or constrained on both sides.

[0016] The valve bridge 200 includes a centrally upstanding rocker arm-engaging tappet head 202, hereinafter referred to as tappet head 202, and two arms 204, 206 formed remote from, extending transversely to, and engaging the tappet head 202. The rocker arm assembly 126 may include a tappet contact surface (not shown) configured to engage the tappet head 202 of the valve bridge 200 for simultaneously pushing the valves 116 into each of the open and / or closed positions.

[0017] In one embodiment of the present disclosure, the valve bridge 200 may include valve stem guide pockets 208, 210 provided on each of the arms 204, 206. The valve stem guide pockets 208, 210 may be configured to engage the associated valve stems 128. An upper surface 211 of the valve stems 128 may be contoured to engage within the corresponding valve stem guide pockets 208, 210. As one skilled in the art will appreciate, the contour may be configured such that the valve stems 128 maintain strong positive contact with the valve stem guide pockets 208, 210 and, therefore, with the valve bridge 200 during operation of the engine 100. In one embodiment of the present disclosure, the valve stem guide pockets 208, 210 may be made of mild steel and manufactured through a milling process.Alternatively, the valve stem guide pockets 208, 210 can be manufactured by a casting process.

[0018] Each of the valve stem guide pockets 208, 210 may include a valve stem contact surface 212 configured to engage the upper surface 211 of the associated valve stem 128. Furthermore, the valve stem guide pockets 208, 210 may include a cavity having an opening 214 at one end and the valve stem contact surface 212 at an opposite end. In one aspect of the present disclosure, the cavity of the valve stem guide pocket 208, 210 may be an inverted frustoconical cavity (as shown in Fig. 3). For example, a first inner diameter D1 of the valve stem guide pockets 208, 210 at the valve stem contact surface 212 is larger than a second inner diameter D2 of the valve stem guide pockets 208, 210 at the opening 214. In an exemplary embodiment of the present disclosure, the second inner diameter D2 of the valve stem guide pockets 208, 210 at the opening 214 may be in a range of approximately 1 mm to 10 mm. In an exemplary embodiment, a ratio of the first inner diameter D1 and the second inner diameter D2 of the valve stem guide pockets 208, 210 may be in a range of approximately 2:1.95 to 2:1.5. Further, a difference between the first inner diameter D1 and the second inner diameter D2 of the valve stem guide pockets 208, 210 is in a range of approximately 1 mm to 15 mm.

[0019] Furthermore, the valve stem guide pockets 208, 210 have a tapered surface 216 extending from the valve stem contact surface 212 toward the opening 214. In an exemplary embodiment of the present disclosure, the tapered surface 216 of the valve stem guide pockets 208, 210 extends at an angle A with respect to a central axis CC' of the valve stem guide pockets 208, 210. For example, the angle A may range from approximately 2 degrees to 15 degrees. In one aspect of the present disclosure, the tapered surface 216 has a beveled edge 218 at the opening 214 of the valve stem guide pocket 208, 210.

[0020] As in the Fig. 2 and Fig. As shown in Figure 3, in one aspect of the present disclosure, the valve bridge 200 may include a lubrication through-bore 220 provided at the valve stem contact surface 212 of each of the valve stem guide pockets 208, 210. The lubrication through-bore 220 may be configured to receive lubricating oil from a lubrication dispenser and distribute it to the cavity of the valve stem guide pockets 208, 210.

[0021] Fig. 4 illustrates a sectional view of a valve bridge 400 according to an alternative embodiment of the present disclosure. The valve bridge 400 may include a rocker arm-engaging tappet head 402 and a pair of arms 404, 406 extending laterally from the tappet head 402. In one embodiment of the present disclosure, the valve bridge 400 may include valve stem guide pockets 408, 410 provided on each of the arms 404, 406, respectively. In an exemplary embodiment, one of the valve stem guide pockets, such as pocket 410, may include an inverted frustoconical cavity, with the second pocket 408 having a rectangular or circular cross-section having the same first inner diameter D1 at a valve stem contact surface 412 and the second inner diameter D2 at an opening 414 of the pocket 408. Further, as in Fig. 4, the valve stem guide pockets 408, 410 have a beveled edge 418 at the opening 414.

[0022] Fig. 5 illustrates a sectional view of a valve bridge 500 according to yet another embodiment of the present disclosure. The valve bridge 500 may include a rocker arm-engaging tappet head 502 and a pair of arms 504, 506 extending laterally from the tappet head 502. In one embodiment of the present disclosure, the valve bridge 500 may include valve stem guide pockets 508, 510 provided on each of the arms 504, 506, respectively. In an exemplary embodiment, one of the valve stem guide pockets, such as pocket 510, has an inverted frustoconical cavity, with the second pocket 508 having a rectangular or circular cross-section. Further, as in Fig. 5, the valve stem guide pocket 508 may be completely milled out to the end of the bridge 500 so that there is no material between the valve pocket 508 and this side of the bridge 500. Industrial applicability

[0023] The industrial applicability of the multi-valve activating valve bridge 200, 400, 500 of the valve activation brewing group 118 of the engine 100 described herein will be readily appreciated from the foregoing discussion.

[0024] Simultaneous activation of pairs of valves belonging to a cylinder in an internal combustion engine is typically achieved by a valve bridge. The valve bridge is activated by a rocker arm to contact terminal ends of valve stems associated with the valves, causing the valves to move back and forth between open and closed positions. In situations of temporary valve sticking, temporary piston-to-valve contact, valve train separation from dynamic operation, or any other similar situation involving simultaneous movement of the valves, the load distribution on the valve bridge may be uneven. This can result in the application of unequal forces and stresses to the valve bridge and valves, which can cause unnecessary damage and breakage to the valve bridge and valves.

[0025] The valve activation assembly 118 with the valve bridge 200, 400, 500 having the valve stem guide pockets 208, 210, 410, 510 according to aspects of the present disclosure functions effectively to allow tilting of the valve bridge 200, 400, 500 around the valve stems 128 in situations of uneven load distribution on the valve bridge 200, 400, 500. Furthermore, the valve stems 128 are in close contact with the valve stem guide pockets 208, 210, 410, 510, preventing the bridge from sliding out of the corresponding pockets 208, 210, 410, 510. Therefore, minimal or no damage is caused to the valves 116, the valve bridge 200, 400, 500, the interface of the valve stems 128 with the corresponding guide pockets 208, 210, 410, 510 and the engine 100.

[0026] Fig. Figure 6 illustrates a perspective view of the valve stems 128 and the valve bridge 200 during normal engine operation. In this case, the valves 116 are in the open and closed positions simultaneously. Furthermore, as shown in Figures Fig. 7 and Fig. 8, the valve bridge 200 can lean toward either the left side or the right side, as desired, in situations of unequal operation of the valves 116 and / or unequal distribution of the load on the valve bridge 200. In addition, the invented frusto-conical cavity of the valve stem guide pockets 208, 210 allows the valves 116 to function at different heights above the cylinder head 104 without malfunction.

Claims

[1] Multi-valve activating valve bridge (200) for an engine (100) with a rocker arm engaging tappet head (202), at least two arms (204, 206) extending transversely to the rocker arm and engaging the tappet head (202), and a valve stem guide pocket (208, 210) provided on each of the arms (204, 206), at least one of the valve stem guide pockets (208, 210) having: a valve stem contact surface (212), a tapered surface (216) extending from the valve stem contact surface (212) toward an opening (214) of the valve stem guide pocket (208, 210), the tapered surface (216) defining an inverted frustoconical cavity, and a first inner diameter (D1) of the valve stem guide pocket (208, 210) at the valve stem contact surface (212) which is greater than a second inner diameter (D2) of the valve stem guide pocket (208, 210) at the opening (214). [2] Multi-valve activating valve bridge (200) according to claim 1, wherein a ratio of the first inner diameter (D1) to the second inner diameter (D2) is in a range of 2:1.95 to 2:1.

5. [3] The multi-valve activating valve bridge (200) of claim 1, wherein the tapered surface (216) is at an angle (A) of 2 degrees to 15 degrees with respect to a central axis (C-C') of the valve stem guide pocket (208, 210). [4] The multi-valve activating valve bridge (200) of claim 1, wherein the tapered surface (216) has a beveled edge at the opening (214) of the valve stem guide pocket (208, 210). [5] The multi-valve activating valve bridge (200) of claim 1 further comprising a lubrication through-bore (220) provided at the valve stem contact surface (212). [6] The multi-valve activating valve bridge (200) according to claim 1 is a floating type valve bridge. [7] Multi-valve activating valve bridge (200) according to claim 1 is made of mild steel. [8] Multi-valve activating valve bridge assembly for an engine (100) with a rocker arm and a multi-valve activating valve bridge (200) with a rocker arm engaging tappet head (202), at least two arms (204, 206) extending transversely to the rocker arm and engaging the tappet head (202), and a valve stem guide pocket (208, 210) provided on each of the arms (204, 206), at least one of the valve stem guide pockets (208, 210) having a valve stem contact surface (212), a tapered surface (216) extending from the valve stem contact surface (212) toward an opening (214) of the valve stem guide pocket (208, 210), the tapered surface (216) defining an inverted frustoconical cavity, and a first inner diameter (D1) of the valve stem guide pocket (208, 210) at the valve stem contact surface (212) which is greater than a second inner diameter (D2) of the valve stem guide pocket (208, 210) at the opening (214).

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