Lifter assembly for valve lift profile modification

Abstract

A valve train assembly for modifying the lift of at least one intake and / or exhaust valve is provided. The valve train assembly includes at least one tappet housed in a rocker housing with at least one rocker arm. The at least one tappet is coupled to an actuator operable to change the tappet from a first configuration in which all cam lobe motion is transmitted to the rocker arm to open and close the intake and / or exhaust valve to a second configuration in which less than all of the cam lobe motion is transmitted to the rocker arm.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 111,702, filed November 10, 2020, which is incorporated herein by reference. Technical Field

[0003] This disclosure relates to tappet assemblies that allow modification of the lift profile of the intake and / or exhaust valves of one or more cylinders in an internal combustion engine. Background Technology

[0004] Cylinder deactivation has been used in various engines for many years to reduce engine pumping power and achieve improved fuel economy. One type of cylinder deactivation tappet assembly known in the art is shown in Figure 1. In Figure 1, roller 6 rotates about shaft 1 while following the camshaft cam angle (not shown). Roller shaft 1 is captured in outer body 2. Inner body 5 is positioned within outer body 2. Freewheeling spring 3 is captured between outer body 2 and inner body 5. Locking pin 4 connects inner body 5 to outer body 2 when extended as shown. Push tube (not shown) engages with push tube housing 8 positioned within inner body 5. Oil is introduced into oil passage 7 by a hydraulic control valve (not shown) to disengage locking pin 4. When locking pin 4 disengages from outer body 2, cam cam angle movement is absorbed by freewheeling spring 3, and no movement is transmitted to push tube, thus allowing the intake or exhaust valve to remain closed. This operating state is called "deactivation". When oil pressure is no longer supplied to the oil passage 7, the locking pin 4 will engage the outer body 2 and reconnect the movement of the outer body 2 and the inner body 5 so as to transmit the camshaft lift event to the push tube to open the corresponding intake or exhaust valve.

[0005] The engagement or disengagement of locking pin 4 is regulated by the pressure in a hydraulic circuit using engine oil as the working fluid. Normally, locking pin 4 is engaged and disengaged only when the pressure in the dedicated locking pin channel rises to the engine's oil gun pressure. This strategy provides mechanical fail-safe protection when no oil pressure is available for engine starting. A drawback of the hydraulic system is that cylinder deactivation is only possible when sufficient oil pressure exists to move the spring-loaded locking pin 4 for disengagement. This becomes particularly challenging at low engine operating speeds or when other components in the lubrication circuit, such as piston cooling nozzles, camshaft phasers, and engine brakes, have high oil demands. Increased oil pump size may also be necessary to accommodate higher lubrication circuit requirements. The use of engine oil also limits potential use during cold conditions due to its high viscosity, and the components themselves are affected by oil cleanliness issues, potentially interfering with tight clearances of moving parts. Therefore, further improvements are expected in this area of ​​expertise. Summary of the Invention

[0006] This document discloses systems, apparatus, and methods relating to modifying the lift profiles of intake and / or exhaust valves of an internal combustion engine, such as for cylinder deactivation, valve lift events shorter than the nominal valve lift duration, and / or multi-stage valve lift. In one embodiment, a mechanical switching mechanism is used to select between a nominal operating mode for valve lift and a modified valve lift operating mode. Therefore, it is unnecessary to adopt or upgrade the engine's lubrication circuit (for existing engines) because no additional requirements are imposed on the lubrication circuit. The cylinder can also operate in either a cylinder deactivation mode or a modified lift mode under operating conditions that are not permitted by hydraulic actuation, such as during cold starts, low-speed operation, or low oil pressure conditions. Similarly, it eliminates the need for potentially costly and difficult-to-manufacture complex drilling and passages for hydraulic circuits. However, this disclosure can also be used in conjunction with a hydraulic system to operate the switching mechanism. The mechanical switching mechanism can also have an internal feedback device to ensure that a cylinder deactivation event occurs upon command, simplifying on-board diagnostic control.

[0007] This summary is provided to introduce some concepts further described below in the illustrative embodiments. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid to limiting the scope of the claimed subject matter. Further embodiments, forms, objects, features, advantages, aspects, and benefits will become apparent from the following description and drawings. Attached Figure Description

[0008] Figure 1 is a partial cross-sectional perspective view of a prior art cylinder deactivation tappet used in an internal combustion engine.

[0009] Figure 2 This is a schematic diagram of an internal combustion engine system.

[0010] Figure 3 It includes the valve lift system Figure 2 An isometric view of a portion of an internal combustion engine.

[0011] Figure 4 This is an isometric view of a valve lift system used in an implementation of an internal combustion engine.

[0012] Figure 5 It is an isometric view of a valve lift mechanism in one embodiment of a single cylinder for an internal combustion engine.

[0013] Figure 6 yes Figure 5 A top view of the valve lift mechanism.

[0014] Figure 7 yes Figure 5 Bottom view of the valve lift mechanism.

[0015] Figure 8A and Figure 8B They are Figure 5 Isometric and sectional views of the valve lifter tappet of the valve lifter mechanism.

[0016] Figure 9A and Figure 9B They are Figure 5 An isometric view and another sectional view of the valve lifter rod of the valve lift mechanism.

[0017] Figure 10 yes Figure 5 An exploded view of the valve lift mechanism.

[0018] Figures 11A to 11C This shows the various operating modes of the valve lifter.

[0019] Figure 12 It has pattern sensing function Figure 5 An isometric view of another embodiment of the valve lift mechanism.

[0020] Figure 13 An example of a modified valve lift for the valve lift mechanism of this disclosure is shown.

[0021] Figure 14 Another embodiment of a valve lift system for an overhead camshaft type internal combustion engine is shown.

[0022] Figure 15 It is used for Figure 14 An isometric view of the valve lift mechanism in one embodiment of the valve lift system.

[0023] Figure 16 yes Figure 15 A top view of the valve lift mechanism.

[0024] Figure 17 yes Figure 15 Bottom view of the valve lift mechanism.

[0025] Figure 18A and Figure 18B They are Figure 15 Isometric and sectional views of the valve lifter tappet of the valve lifter mechanism.

[0026] Figure 19A and Figure 19B They are Figure 15 An isometric view and another sectional view of the valve lifter rod of the valve lift mechanism.

[0027] Figure 20 yes Figure 15 An exploded view of the valve lift mechanism.

[0028] Figures 21A to 21C It shows Figure 15 Various operating modes of the valve lift tappet. Detailed Implementation

[0029] For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments shown in the accompanying drawings, and these embodiments will be described using specific language. However, it will be understood that this is not intended to limit the scope of the invention, and any changes and further modifications to the illustrated embodiments and any further applications of the principles of the invention shown herein are contemplated by those skilled in the art.

[0030] Figure 2 An internal combustion engine system 100 according to one embodiment of this application is shown. System 100 includes an internal combustion engine 102 having an intake system 104 and an exhaust system 106. Engine 102 can be any type of engine, and in one specific embodiment is a diesel engine comprising a plurality of cylinders 108, each cylinder housing a piston. Cylinders 108 receive an intake airflow 124 and burn fuel supplied thereto to produce an exhaust airflow 126 from each cylinder. In the illustrated embodiment, engine 102 includes six cylinders connected to an intake manifold 120 and an exhaust manifold 122. Engine 102 can be an inline engine with a single cylinder bank, but other embodiments include a V-cylinder arrangement, a W-type engine, or any engine arrangement with one or more cylinders. It is envisioned that engine 102 be provided as part of a powertrain for a vehicle (not shown).

[0031] refer to Figure 3 An embodiment of a valve lift system for one cylinder of an engine 102 is shown. The engine 102 includes a crankshaft 130, a piston 140, a camshaft 150, and a valve opening mechanism 190 including a valve lift system 170. The piston 140 is housed in a corresponding cylinder 108 and is rotatably connected to the crankshaft 130 by means of a connecting rod 132, such that the reciprocating motion of the piston 140 rotates the crankshaft 130, as is known in the art. The crankshaft 130 also includes a first crankshaft gear 134, which is connected to a second camshaft gear 136, which is connected to the camshaft 150. Rotation of the crankshaft 130 causes the camshaft 150 to rotate at, for example, half the speed of the crankshaft 130, wherein the first crankshaft gear 134 and the second camshaft gear 136 provide gear reduction, as is known in the art. Other embodiments envision other types of connections between the crankshaft 130 and the camshaft 150, such as chain or belt drive, and / or other gear ratios.

[0032] Each cylinder 108 of engine 102 houses a piston 140, which is connected to a crankshaft 130 and a camshaft 150. Each cylinder 108 also includes at least one intake valve 142, which is opened and closed by a valve opening mechanism 190 connected to an intake cam lob 152 of the camshaft 150. Opening the intake valve 142 allows intake airflow through an intake opening 142a into the combustion chamber of the corresponding cylinder 108. In the illustrated embodiment, the intake valve 142 includes a first intake valve and a second intake valve connected by an intake crosshead 144. The intake crosshead 144 is connected to an intake rocker arm 148, which is rotatable about a rocker arm axis in response to the following: when the intake valve opening lob of the intake cam lob 152 passes abutting against the intake cam follower 145 at the end of the push tube 146, the intake valve opening lob of the intake cam lob 152 pushes the intake push tube 146.

[0033] Each cylinder 108 also includes at least one exhaust valve 172. At least one exhaust valve 172 is opened by a valve opening mechanism 190 to allow exhaust gases produced by the combustion of the charge flow to escape from the combustion chamber of the corresponding cylinder 108 through an exhaust opening 172a. In the illustrated embodiment, the exhaust valve 172 includes a first exhaust valve and a second exhaust valve connected by an exhaust crosshead 174. Each exhaust valve 172 also includes a valve spring 176 actuated by an exhaust rocker arm 178 via the exhaust crosshead 174 to open and close the exhaust valve 172 in response to an exhaust valve opening cam 154 acting on an exhaust push pipe 180.

[0034] In the illustrated embodiment, the exhaust pushrod 180 extends through a cavity in the cylinder block of the engine 102 and engages with the exhaust cam lob 154 via an exhaust cam follower 182. The exhaust cam follower 182 engages with the end of the exhaust push pipe 180. The exhaust push pipe 180 translates in response to rotation of the exhaust cam lob 154 acting on the exhaust cam follower 182 and acts via a tappet 200 to pivot the exhaust rocker arm 178 about the rocker arm axis 184. A similar arrangement is provided for the intake push pipe 146.

[0035] The valve lift system 170 also includes a valve opening mechanism 190 employing valve lift tappets 200a, 200b on each of the push tubes 146, 180. Each tappet 200a, 200b is operable to provide variable lift of the intake valve 142 and / or exhaust valve 172 when a lift profile different from the standard or nominal lift profile is desired, such as during cylinder deactivation or Miller cycle, as further discussed below.

[0036] refer to Figure 4An implementation scheme for the valve lift system 170 exists. As discussed above, the second camshaft gear 136 is driven by the first crankshaft gear 134 at a certain transmission ratio. The second camshaft gear 136 rotates the camshaft 150, which includes the intake cam lob 152 and the exhaust cam lob 154. The intake cam follower 145 follows the lob profile of the intake cam lob 152. The exhaust cam follower 182 follows the lob profile of the exhaust cam lob 154. The intake push pipe 146 transmits the motion of the intake cam follower 145 to the cylinder deactivation tappet 200a. The exhaust push pipe 180 transmits the motion of the exhaust cam follower 182 to a second identical cylinder deactivation tappet 200b. The cylinder deactivation tappets 200a and 200b will be described in detail below.

[0037] Cylinder deactivation tappets 200a and 200b reciprocate within cavities provided in the rocker arm housing 202. A two-position actuator 204 is fixed to the rocker arm housing 202. In one position of the actuator 204, the cylinder deactivation tappets 200a and 200b are active and transmit motion from push tubes 146 and 180 to the intake rocker arm 148 or the exhaust rocker arm 178. The intake rocker arm 148 and the exhaust rocker arm 178 then actuate the crosshead and the intake and exhaust valves as discussed above. In a second position of the actuator 204, the cylinder deactivation tappets 200a and 200b are deactivated and absorb motion from the push tubes 146 and 180. In this mode, no motion (or reduced motion) is transmitted to the intake rocker arm 148 or the exhaust rocker arm 178. This state of non-transmission of motion is called cylinder deactivation.

[0038] refer to Figure 5 An embodiment of the valve opening mechanism for the valve lift system 170 is shown. As previously described, the movement of the camshaft cam angles 152, 154 is transmitted upwards via the intake pusher 146 and the exhaust pusher 180. The intake rocker arm 148 and the exhaust rocker arm 178 pivot about a corresponding one of the rocker arm shafts 210a, 210b. The rocker arm shafts 210a, 210b are secured using center cap screws 212a, 212b. An adjusting screw 214 with a ball pivot foot 216 is positioned at the end of each of the rocker arms 148, 178. The adjusting screw 214 is used to set the clearance between the ball pivot foot 216 and the valve crossheads 144, 174 to a predetermined value during assembly. Once the clearance value is reached, a locking nut 218 secures the adjusting screw 214 in the desired position. Valve crossheads 144 and 174 are used to transmit the movement of rocker arms 148 and 178 to the two intake valves 142 or the two exhaust valves 172. Valves 142 and 172 are fixed in the cylinder head (not shown) by valve springs 176 and spring retainers 222.

[0039] Two cap screws 224 are used to secure the actuator 204 to the rocker arm housing 202. The actuator 204 is connected to the engine wiring harness and ECM via an electrical connector 226. The actuator 204 actuates a rack 230, which engages with each of the cylinder deactivation tappets 200a, 200b and will be described later.

[0040] Further reference Figure 6 Cylinder deactivation tappet 200a passes through the intake rocker arm 148 via an elongated slot 232a. Cylinder deactivation tappet 200a engages with the intake rocker arm 148 via a collar 234a. Similarly, cylinder deactivation tappet 200b passes through the exhaust rocker arm 178 via an elongated slot 232b. Cylinder deactivation tappet 200b engages with the exhaust rocker arm 178 via a collar 234b. Actuator 204 actuates rack 230, which engages with each of the cylinder deactivation tappets 200a and 200b. Actuator 204 moves pin 236 along axis 238 to activate or deactivate cylinder deactivation tappets 200a and 200b.

[0041] Further reference Figure 7 This view depicts rack 230 engaged with cylinder deactivation tappets 200a and 200b at positions 240a and 240b. When actuator pin 236 moves rack 230 along axis 238 in the direction of arrow 242, the rack causes rotation of tappets 200a and 200b, indicated by arrows 244a and 244b. Similarly, when rack 230 moves in the opposite direction of arrow 242, the rotational movement of cylinder deactivation tappets 200a and 200b is reversed along arrows 244a and 244b. This back-and-forth movement of actuator pin 236 can be directly controlled by actuator 204, or conversely, one direction of movement can be controlled or assisted by a spring (not shown).

[0042] refer to Figure 8A and Figure 8BThe components of cylinder deactivation tappets 200a and 200b are shown in both isometric views and a first sectional view. Cylinder deactivation tappets 200a and 200b are composed of an outer body 247 and an inner body 253. The inner body 253 includes a push-tube housing 245 that engages with an intake push-tube 146 or an exhaust push-tube 180. The inner body 253 also has an extension rod 258 inside a freewheeling spring 246, which rests at one end against a freewheeling spring pad 256 and at the opposite end 257 against a freewheeling spring retainer 248. The freewheeling spring retainer 248 is constrained to the inner body 253 by a freewheeling spring retainer stop 259. The freewheeling spring retainer stop 259 can be formed in place after the assembly of the freewheeling spring 246 and the freewheeling spring retainer 248 to capture the freewheeling spring 246 using a certain amount of spring preload. Alternatively, the freewheeling spring retainer stop 259 can be replaced by a threaded ring or any other method to prevent the freewheeling spring retainer 248 from slipping off the extension rod 258.

[0043] When the cylinder is deactivated, tappets 200a and 200b are as follows: Figure 8A and Figure 8B When the orientation shown is indicated, it is referred to as being in the "active" mode. In this mode, motion from push tubes 146, 180 is transmitted to rocker arms 148, 178. The load from push tubes 146, 180 is transmitted from the push tube receptacle 245 in the inner body 253 via shear pins 252 engaging with triangular flanges 251 on the outer body 247. The outer body 247 transmits motion to the rocker arms 148, 178 via collars 234a, 234b. Collars 234a, 234b are pressed against the outer body 247 at position 254 and are forcibly constrained at position 255. Collars 234a, 234b may be made of a different material or hardness than the outer body 247 to reduce wear between the rocker arms 148, 178 and the collars 234a, 234b interfaces. Oil port 262 may be connected to an oil source (pressurized or unpressurized) to provide lubrication to the push tube receptacle 245. Gear teeth 261 are machined into the outer body 247 in a radial sector to engage with rack 230. A small clearance 260 is required between the idler spring retainer 248 and the outer body 247 to minimize the force required from actuator 204 when rotating the outer body 247 about the inner body 253.

[0044] The inner body 253 is constrained to the rocker arm housing 202 in a steering manner via the shear pin 252. This rotation of the outer body 247 of the tappet changes the cylinder deactivation tappets 200a, 200b from an "active" mode to a "deactivated" mode. This change is accomplished when the push tubes 146, 180 are unloaded, or in other words, when the camshaft cam angles 152, 154 are on the base circle or in a no-lift condition. The two openings 249, 250 allow the shear pin 252 and the inner body 253 to reciprocate up and down within the outer body 247 without moving the rocker arms 148, 178. During this condition, the valve mechanism remains in contact with the freewheeling spring 246.

[0045] Figure 9A and Figure 9B With Figure 8B Both the isometric view, offset by 90 degrees, and the second sectional view show the components of the cylinder deactivation tappets 200a and 200b. In this view, the shear pin 252 is shown extending beyond the main diameter of the outer body 247 to dimension 263. This allows the inner body 253 and its associated components to remain stationary, while the position of the outer body 247 can be rotated from an "active" mode to a "deactivated" mode.

[0046] Figure 10 An exploded view of a single cylinder deactivation mechanism is shown. For clarity, the intake rocker arm 148 has been omitted. Cylinder deactivation tappets 200a and 200b are positioned in cylinder deactivation tappet cavities 269 and 264 within the rocker arm housing 202. Grooves 265 and 267 are broached into the cylinder deactivation tappet cavities 264 and 269 to align the cylinder deactivation tappets 200b and 200a using a shear pin 252 extending 263 from the outer body. This also restricts rotation of the inner body 253 of the cylinder deactivation tappets 200a and 200b, such that the rack 230 rotates the outer body 247 only during a cylinder deactivation event. The rack 230 is received in a rack cavity 268 within the rocker arm housing 202. The rack cavity 268 opens into the cylinder deactivation tappet cavities 264 and 269 through a position opening 266. Opening 266 allows rack 230 to engage with gear teeth 261 machined into the outer body 247 of each cylinder deactivation tappet 200a, 200b. Recesses 265, 267 are positioned 180 degrees to each other, allowing the same cylinder deactivation tappet design to be used for both intake rocker arm 148 and exhaust rocker arm 178. This allows rack 230 to impart different rotational directions 244a, 244b to tappets 200a, 200b based on which side of rack 230 the cylinder deactivation tappets 200a, 200b are positioned on.

[0047] Figures 11A to 11C This illustrates the cylinder deactivation tappet operation mode. Figure 11AIn this mode, the inner body 253 is clocked relative to the outer body 247, so the shear pin 252 is in direct contact with the outer body 247 at position 271. Movement from the cam lobe angles 154, 152, the intake cam follower 145, the exhaust cam follower 182, and the pushpipes 146, 180 is transmitted directly to the rocker arms 148, 178 and the valves 142, 172 via the cylinder deactivation tappets 200a, 200b. For clarity, the rocker arm interface 272 of the contact rings 234a, 234b is shown. In this mode, the engine cylinders are "active". Figure 11B In this mode, the outer body 247 is synchronized with the inner body 253 via the actuator 204, rack 232, and gear teeth 261. In this mode, the clearance 273 is now positioned above the shear pin 252. As previously mentioned, from Figures 11A to 11B The change occurs when the valve mechanism is unloaded. Figure 11C In this mode, push tubes 146 and 180 actuate the inner body 253, but because the shear pin 252 is not in axial contact with the outer body 247, the movement of push tubes 146 and 180 "disappears," and rocker arms 148 and 178 remain stationary when the idler spring 246 is compressed. In this mode, the engine cylinders are "disused." The engine will continue to operate... Figure 11B The patterns and Figure 11C The operation continues between modes until the actuator 204 reverses its movement and the cylinder deactivates, and the tappets 200a and 200b are reoriented. Figure 11A Until the "Activity" mode is in position.

[0048] Figure 12 An optional pattern sensor 274 is shown, which can be used to sense the position of rack 230 via a Hall effect strategy or other means. This type of feature can be beneficial for on-board diagnostics. As a lower-cost option, position sensing can also be integrated within actuator 204.

[0049] Although various aspects of this disclosure have been described in the context of cylinder decommissioning, tappets 200a, 200b (or tappets 1200a, 1200b discussed below) do not need to absorb the entire lift and can be reconfigured to absorb only a portion of the lift, and when combined with a rigid freewheeling spring, can produce the following: Figure 13The valve lift profile is shown. This will achieve both standard-duration and shorter-duration valve lift events. This type of operation is commonly referred to as the Miller cycle. A similar arrangement can be used on the exhaust side of the engine to achieve an exhaust valve early opening strategy. The tappets and actuators can also be extended to achieve a multi-stage lift loss function, instead of the dual-mode operation described above. The cylinder deactivation tappets can also be configured with a hydraulic clearance adjuster. Finally, although the invention is described in terms of an electronic actuator, the system can also be configured with a hydraulic system to use engine oil as the working fluid to move the rack 230.

[0050] refer to Figure 14 Another embodiment of a valve lift system 1170 for an overhead camshaft type engine 102 is shown. The valve lift system 1170 is mounted on a camshaft 1150 connected to at least one exhaust valve 1172, which is opened and closed by a valve opening mechanism 1190 connected to an exhaust cam lob 1154 of the camshaft 1150. In the illustrated embodiment, the exhaust valve 1172 is a single valve, but an additional exhaust valve connected via an exhaust crosshead (not shown) may be provided. The exhaust valve 1172 is connected to a valve spring 1176 via an exhaust rocker arm 1178, which is rotatable about a rocker arm axis in response to the following: when the exhaust valve opening lob of the exhaust cam lob 1154 abuts against a cam follower 1180, the exhaust valve opening lob of the exhaust cam lob 1154 pushes the exhaust cam follower 1180 (…). Figure 17 ).

[0051] One or more intake valves 1142 are also provided, which are opened by a valve opening mechanism 190. In the illustrated embodiment, the intake valve 1142 includes a first intake valve and a second intake valve connected by an intake crosshead 1144. Each intake valve 1142 also includes a valve spring 1176 actuated by an intake rocker arm 1148 via the intake crosshead 1144 to open and close the intake valve 1142 in response to an intake valve opening cam cam cam follower 1146 acting on the intake cam ...

[0052] The valve lift system 1170 also includes a valve opening mechanism 1190 with valve lift tappets 1200a and 1200b respectively on each of the cam followers 1146 and 1180. Each tappet 1200a and 1200b is operable to provide variable lift of the intake and / or exhaust valves 1142 and 1172 when a lift profile different from the standard or nominal lift profile is desired, such as during cylinder deactivation or Miller cycle.

[0053] refer to Figures 15 to 17Cylinder deactivation tappets 1200a and 1200b reciprocate within cavities in a cam cap 1202, which can be secured to the engine's cylinder head, camshaft carrier, or valve cover using fasteners 1203. An actuator 1204 is secured to the cam cap 1202. The actuator 1204 can be connected to the engine's wiring harness and ECM via an electrical connector. In one position of the actuator 1204, the cylinder deactivation tappets 1200a and 1200b are active and transmit motion from cam followers 1146 and 1180 to the intake rocker arm 1148 or the exhaust rocker arm 1178. The intake rocker arm 1148 and the exhaust rocker arm 1178 then actuate the crosshead (if provided) as discussed above, as well as the intake and exhaust valves. In the second position of actuator 1204, cylinder deactivation tappets 1200a and 1200b are deactivated and absorb movement from cam lobe angles 1152 and 1154. In this mode, no movement (or reduced movement) is transmitted to intake rocker arm 1148 or exhaust rocker arm 1178. This non-transmitting movement operating state is called cylinder deactivation.

[0054] As previously described, the movement of the camshaft cam angles 1152 and 1154 is transmitted upwards via the intake cam follower 1146 and the exhaust cam follower 1180. The intake rocker arm 1148 and the exhaust rocker arm 1178 pivot about a corresponding one of the rocker arm shafts 1210a and 1210b. The rocker arm shafts 1210a and 1210b are secured using center cap screws 1212a and 1212b. An adjusting screw 1214 may also be provided to set the clearance to a predetermined value during assembly. The valve crosshead 1174 is used to transmit the movement of the rocker arm 1178 to the two exhaust valves 1172.

[0055] Cylinder deactivation tappet 1200a passes through the intake rocker arm 1148 via a long slot 1232a. Cylinder deactivation tappet 1200a connects to the intake rocker arm 1148 via a collar 1234a. Similarly, cylinder deactivation tappet 1200b passes through the exhaust rocker arm 1178 via a long slot 1232b. Cylinder deactivation tappet 1200b connects to the exhaust rocker arm 1178 via a collar 1234b. Actuator 1204 moves pin 1236 along axis 1238 to activate or deactivate cylinder deactivation tappets 1200a and 1200b.

[0056] When actuator pin 1236 moves along axis 1238 in the direction of arrow 1242, it causes rotation of tappets 1200a and 1200b, indicated by arrows 1244a and 1244b. Similarly, when pin 1236 moves in the opposite direction of arrow 1242, the cylinder deactivates the rotational movement of tappets 1200a and 1200b in the opposite direction of arrows 1244a and 1244b. This forward and backward movement of actuator pin 1236 can be directly controlled by actuator 1204, or conversely, one of the directions of movement of tappets 1200a and 1200b can be controlled or assisted by springs, for example, for the opposite movement.

[0057] refer to Figure 18A and Figure 18B The components of cylinder deactivation tappets 1200a and 1200b are shown in both isometric views and a first sectional view. Cylinder deactivation tappets 1200a and 1200b are composed of an outer body 1247 and an inner body 1253. The outer body 1247 includes a cam follower housing 1245 that houses corresponding cam followers 1146 and 1180. The outer body 1247 also has a freewheeling spring pad 1256 positioned therein. The outer body 1247 and inner body 1253 house an extension rod 1258 within the freewheeling spring 1246, which rests against the freewheeling spring pad 1256 at one end and against the freewheeling spring retainer 1248 at the opposite end 1257. The freewheeling spring retainer 1248 is constrained to the outer body 1247 by the freewheeling spring retainer stop 259 or any suitable threaded ring or device to prevent the freewheeling spring retainer 1248 from slipping off the extension rod 1258.

[0058] When the cylinder is deactivated, tappets 1200a and 1200b are as follows: Figure 18A and Figure 18B When the orientation is shown, it is referred to as being in the "active" mode. In this mode, motion from cam followers 1146, 1180 is transmitted to rocker arms 1148, 1178. The load from cam followers 1146, 1180 is transmitted from cam follower housing 1245 in outer body 1247 via axial arm 1252, which extends axially from the upper end of outer body 1247 to engage flange 1251 on collars 1234a, 1234b of inner body 1253. Inner body 1253 transmits motion to rocker arms 1148, 1178 via collars 1234a, 1234b. Collars 1234a, 1234b also include radially extending arms 1261, which are engaged by actuator 1204 to rotate collars 1234a, 1234b when cylinder deactivation is required.

[0059] The outer body 1247 is steeringally constrained to the rocker arms 1148, 1178 via guide pin 1259. This rotation of the inner body 1253 of the tappet changes the cylinder deactivation tappets 1200a, 1200b from an "active" mode to a "deactivated" mode. This change is accomplished when the camshaft cam angles 1152, 1154 are on the base circle or in a no-lift condition. The two openings or gaps 1249, 1250 in the collars 1234a, 1234b allow the axial arm 1252 and the outer body 1247 to reciprocate relative to the inner body 1253 without moving the rocker arms 1148, 1178. During this condition, the valve mechanism remains in contact with the freewheeling spring 1246.

[0060] Figure 19A and Figure 19B With Figure 18B Both the isometric view, offset by 90 degrees, and the second sectional view show the components of the cylinder deactivation tappets 1200a and 1200b. In this view, the axial arm 1252 is shown extending to contact the flange 1251 on the collars 1234a and 1234b of the inner body 1253. Furthermore, a guide pin 1259 is provided so that the outer body 1247 can engage the cam cap 1202 and remain stationary, while the position of the inner body 1253 can be rotated from an "active" mode to a "deactivated" mode.

[0061] Figure 20 An exploded view of a single cylinder deactivation mechanism is shown. Cylinder deactivation tappets 1200a and 1200b are positioned in cylinder deactivation tappet cavities 1269 and 1264 within a cam cap 1202. Grooves 1265 and 1267 are broached into the cylinder deactivation tappet cavities 1269 and 1264 to align the cylinder deactivation tappets 1200b and 1200a using a guide pin 1259. This also constrains the rotation of the outer body 1247 of the cylinder deactivation tappets 1200a and 1200b, such that the actuator 1204 rotates the inner body 1253 only during a cylinder deactivation event. The actuator 1204 is received in a cavity 1268 within the cam cap 1202. Cavity 1268 opens into the cylinder deactivation tappet cavities 1264 and 1269 through a position opening 1266. Opening 1266 allows actuator 1204 to contact the radial arm 1261 of each cylinder deactivation tappet 1200a, 1200b. Recesses 1265, 1267 are positioned 180 degrees to each other, so that the same cylinder deactivation tappet design can be used for both intake rocker arm 1148 and exhaust rocker arm 1178.

[0062] Figures 21A to 21C This illustrates the cylinder deactivation tappet operation mode. Figure 21AIn this mode, the outer body 1247 is synchronized with the inner body 1253, so the axial arm 1252 is in direct contact with the flange 1251 of the collars 1234a and 1234b. Movement from the cam lobe angles 1152 and 1154 and the cam followers 1146 and 1180 is directly transmitted to the rocker arms 1148 and 1178 and the valves 1142 and 1172 via the cylinder deactivation tappets 1200a and 1200b. In this mode, the engine cylinders are "active". Figure 21B In this mode, the inner body 1253 is synchronized with the outer body 1247 by the movement of the actuator 204. In this mode, the gap 1249 is now located above the axial arm 1252. As previously mentioned, from Figures 21A to 21B The change occurs when the valve mechanism is unloaded. Figure 21C In this mode, cam followers 1146 and 1148 actuate the outer body 1247, but because the axial arm 1252 is not in axial contact with the inner body 1253, the movement of cam followers 1146 and 1180 "disappears," and rocker arms 1148 and 1178 remain stationary when the idler spring 1246 is compressed. In this mode, the engine cylinders are "disused." The engine will continue to operate... Figure 21B The patterns and Figure 21C The operation continues between different modes until the actuator 1204 reverses its movement and the cylinder is deactivated. Tappets 1200a and 1200b are then reoriented via return springs, etc. Figure 21A Until the "Activity" mode is in position.

[0063] Various aspects of this disclosure are envisioned. For example, a valve mechanism assembly for an internal combustion engine includes a tappet positioned between a camshaft and an intake or exhaust valve. The tappet has at least two operating modes. One mode transmits all cam lobe motion to the intake or exhaust valve, and a second mode transmits partial or no cam lobe motion to the intake or exhaust valve. The tappet mode is adjusted using an actuator that alters the angular orientation of the inner and outer bodies of the tappet.

[0064] On the other hand, the valve mechanism assembly of an internal combustion engine includes at least two tappets positioned between the camshaft and the corresponding intake and / or exhaust valves. Each tappet has at least two operating modes. One mode transmits all cam lobe motion to the intake and exhaust valves, and a second mode transmits partial or no cam lobe motion to the intake and exhaust valves. The tappet modes are simultaneously adjusted using an actuator that changes the angular orientation between the inner and outer bodies of each tappet.

[0065] On the other hand, a valve mechanism assembly of an internal combustion engine includes a rocker arm housing that houses at least one tappet. The at least one tappet has at least two operating modes. One mode transmits all camshaft cam movement to either the intake or exhaust valve, and a second mode transmits only a portion of the camshaft cam movement or no camshaft cam movement to either the intake or exhaust valve.

[0066] On the other hand, the valve mechanism assembly of an internal combustion engine includes at least one rocker arm assembly. At least one rocker arm assembly directly contacts at least one tappet. At least one tappet has at least two operating modes. One mode transmits all camshaft cam movement to either the intake or exhaust valve, and a second mode transmits only a portion of the camshaft cam movement or no camshaft cam movement to either the intake or exhaust valve.

[0067] According to another aspect, an internal combustion engine system includes a cylinder housing a piston operably connected to a crankshaft. The cylinder also includes at least one intake valve and at least one exhaust valve for selectively opening and closing corresponding portions of at least one intake port and at least one exhaust port of the cylinder. The internal combustion engine system further includes a camshaft including a first cam lob and a second cam lob, wherein the first cam lob and the second cam lob are rotatable with rotation of the camshaft. The internal combustion engine system also includes a valve lifter mechanism connecting the first cam lob and the second cam lob to corresponding portions of the at least one intake valve and the at least one exhaust valve. The valve lifter mechanism includes a first tappet connecting the at least one intake valve to the first cam lob and a second tappet connecting the at least one exhaust valve to the second cam lob. The valve lift mechanism includes a single actuator that simultaneously reconfigures a first tappet and a second tappet from a first configuration to a second configuration. In the first configuration, all movement from the first cam cam angle and the second cam cam angle is transmitted to at least one connected intake valve and at least one connected exhaust valve. In the second configuration, less than all movement from the first cam cam angle and the second cam cam angle is transmitted to at least one connected intake valve and at least one connected exhaust valve.

[0068] In one embodiment, the actuator includes a rack that engages with the outer surface of each of a first tappet and a second tappet, such that rotation of the rack causes a portion of each of the first tappet and the second tappet to rotate from a first configuration to a second configuration.

[0069] In one embodiment, each of the first and second push rods includes an inner body housed within an outer body, and in a first configuration, the inner and outer bodies are axially locked to prevent axial movement relative to each other, and in a second configuration, the outer body rotates relative to the inner body, thus unlocking the inner and outer bodies axially to allow axial movement relative to each other.

[0070] In one embodiment, the valve lift mechanism includes a first rocker arm connected to at least one intake valve, an intake cam follower contacting a first cam, and an intake push tube connecting the intake cam follower to a first tappet. The valve lift mechanism also includes a second rocker arm connected to at least one exhaust valve, an exhaust cam follower contacting a second cam, and an exhaust push tube connecting the exhaust cam follower to a second tappet.

[0071] In one implementation, in a second configuration of the first and second tappets, in response to the first and second cam lobes respectively contacting the intake cam follower and the exhaust cam follower, the intake pushrod and the exhaust pushrod are allowed to translate relative to the first and second tappets respectively, thus keeping at least one intake valve and at least one exhaust valve closed.

[0072] In the implementation scheme, the first tappet and the second tappet each include: an outer body including a collar that engages with a corresponding one of the first rocker arm and the second rocker arm; and an inner body that engages with a corresponding one of the intake push pipe and the exhaust push pipe.

[0073] In the implementation scheme, in the first configuration, the inner and outer bodies of each of the first and second tappets are locked, such that the intake push pipe and exhaust push pipe, respectively, act on the corresponding one of the first rocker arm and the second rocker arm through the displacement generated by the first cam cam angle and the second cam cam angle, and pivot it. In the second configuration, the inner and outer bodies of each of the first and second tappets are unlocked, such that the displacement generated by the intake push pipe and exhaust push pipe, respectively, through the first cam cam angle and the second cam cam angle, is lost due to the displacement of the inner body within the outer body, and does not act on the corresponding one of the first and second rocker arms.

[0074] In one embodiment, the first and second tappets are housed within a rocker arm housing, and an actuator is mounted to the rocker arm housing and extends through a cavity in the rocker arm housing to a position between the first and second tappets. In another embodiment, the first and second tappets are in direct contact with their counterparts in the first and second rocker arm assemblies housed within the rocker arm housing.

[0075] In one embodiment, the actuator includes a pin that is actuated to contact a radially extending arm of each of the first and second tappets, such that displacement of the pin causes a portion of each of the first and second tappets to rotate from a first configuration to a second configuration.

[0076] In one embodiment, each of the first and second push rods includes an inner body housed within an outer body, and in a first configuration, the inner and outer bodies are axially locked to prevent axial movement relative to each other, and in a second configuration, the inner body rotates relative to the outer body, thus unlocking the inner and outer bodies axially to allow axial movement relative to each other.

[0077] In one embodiment, the valve lift mechanism includes: a first rocker arm connected to at least one intake valve and an intake cam follower contacting a first cam and a first tappet; and a second rocker arm connected to at least one exhaust valve and an exhaust cam follower contacting a second cam and a second tappet.

[0078] On the other hand, a tappet for modifying valve lift in a valve mechanism system for an internal combustion engine includes an elongated inner body housed within an outer body. The inner and outer bodies include a locking configuration in which they are axially constrained relative to each other to provide a first valve lift in response to a cam lobe profile acting on the tappet. The inner and outer bodies are then axially rotated relative to each other to an unlocked configuration to provide a second valve lift in response to a cam lobe profile acting on the tappet, wherein the second valve lift is less than the first valve lift.

[0079] In one embodiment, the inner body is spring-biased relative to the outer body toward a locking configuration. In another embodiment, the outer body includes external teeth engaged by an actuator to rotate the outer body relative to the inner body. In yet another embodiment, the outer body includes a collar extending outwardly therefrom for direct contact with a rocker arm of the valve mechanism assembly.

[0080] In one implementation, a shear pin engages with an inner body and extends through an outer body. In a locking configuration, the shear pin contacts the outer body to prevent axial movement of the inner body relative to the outer body, and in an unlocking configuration, the shear pin aligns with an axially extending opening in the outer body to allow axial movement of the inner body relative to the outer body.

[0081] In another aspect, a valve mechanism system for an internal combustion engine includes a rocker arm housing and at least one tappet positioned within the rocker arm housing. The at least one tappet is configured to operate in a first mode and a second mode. In the first mode, the at least one tappet is configured to transmit a first valve lift in response to a cam cam profile acting on the at least one tappet, and in the second mode, the at least one tappet is configured to transmit a second valve lift in response to a cam cam profile acting on the at least one tappet, wherein the second valve lift is less than the first valve lift.

[0082] In one embodiment, at least one pusher includes an elongated inner body housed within an outer body. In a first mode, the inner and outer bodies are axially constrained relative to each other, and in a second mode, the inner and outer bodies rotate axially relative to each other, thus allowing axial movement of the inner and outer bodies relative to each other. In another embodiment, an actuator is mounted to the rocker arm housing, the actuator engaging with at least one pusher to cause axial rotation of the inner and outer bodies relative to each other.

[0083] In one embodiment, a rocker arm is disposed within a rocker arm housing, the rocker arm being positioned around and in direct contact with at least one tappet. The at least one tappet pivots the rocker arm in response to valve lift.

[0084] In another aspect, a valve mechanism system for an internal combustion engine includes a rocker arm and at least one tappet positioned in direct contact with the rocker arm for pivoting the rocker arm. The at least one tappet is configured to operate in both a first mode and a second mode. In the first mode, the at least one tappet is configured to transmit a first valve lift via the rocker arm in response to a cam lobe profile acting on the at least one tappet, and in the second mode, the at least one tappet is configured to transmit a second valve lift via the rocker arm in response to a cam lobe profile acting on the at least one tappet, wherein the second valve lift is less than the first valve lift.

[0085] In one embodiment, a rocker arm housing is provided, and at least one tappet is positioned within the rocker arm housing. The rocker arm is positioned within the rocker arm housing about the at least one tappet.

[0086] In another aspect, a valve mechanism system for an internal combustion engine includes: a cam cap for engaging with a cylinder head, camshaft carrier, or valve cover; and at least one tappet positioned within the cam cap for engaging with a corresponding cam lobe angle. The at least one tappet is configured to operate in a first mode and a second mode. In the first mode, the at least one tappet is configured to transmit a first valve lift in response to a cam lobe angle profile acting on the at least one tappet, and in the second mode, the at least one tappet is configured to transmit a second valve lift in response to a cam lobe angle profile acting on the at least one tappet, wherein the second valve lift is less than the first valve lift.

[0087] While the invention has been shown and described in detail in the accompanying drawings and foregoing description, these drawings and description are to be regarded as illustrative rather than restrictive in nature, and it should be understood that only certain exemplary embodiments have been shown and described. Those skilled in the art will appreciate that many modifications can be made to the exemplary embodiments without substantially departing from the invention. Therefore, all such modifications are intended to be included within the scope of this disclosure as defined by the appended claims. Reading the claims, it is not intended that the claims be limited to only one item when words such as “a,” “one,” “at least one,” or “at least a portion” are used, unless there is an explicit statement to the contrary in the claims. When the language “at least a portion” and / or “a portion” is used, the item may include a portion and / or the entire item, unless there is an explicit statement to the contrary.

Claims

1. An internal combustion engine system, comprising: A cylinder that houses a piston operably connected to a crankshaft, the cylinder further comprising at least one intake valve and at least one exhaust valve for selectively opening and closing corresponding of at least one intake port and at least one exhaust port of the cylinder; A camshaft, comprising a first cam cam angle and a second cam cam angle, wherein the first cam cam angle and the second cam cam angle are rotatable as the camshaft rotates; as well as A valve lifter mechanism that connects a first cam lobe and a second cam lobe to corresponding of at least one intake valve and at least one exhaust valve, the valve lifter mechanism including a first tappet connecting the at least one intake valve to the first cam lobe and a second tappet connecting the at least one exhaust valve to the second cam lobe, the valve lifter mechanism including a single actuator that simultaneously reconfigures the first tappet and the second tappet from a first configuration to a second configuration, in the first configuration, all movements from the first cam lobe and the second cam lobe are transmitted to the connected at least one intake valve and at least one exhaust valve, in the second configuration, less than all movements from the first cam lobe and the second cam lobe are transmitted to the connected at least one intake valve and at least one exhaust valve.

2. The system of claim 1, wherein the actuator includes a rack that engages with the outer surface of each of the first tappet and the second tappet, such that rotation of the rack causes a portion of each of the first tappet and the second tappet to rotate from the first configuration to the second configuration.

3. The system of claim 1, wherein each of the first push rod and the second push rod includes an inner body housed within an outer body, and in the first configuration, the inner body and the outer body are axially locked to prevent axial movement relative to each other, and in the second configuration, the outer body rotates relative to the inner body, thereby axially unlocking the inner body and the outer body to allow axial movement relative to each other.

4. The system according to claim 1, wherein the valve lift mechanism comprises: A first rocker arm is connected to the at least one intake valve, an intake cam follower that contacts the first cam, and an intake push tube that connects the intake cam follower to the first tappet. as well as A second rocker arm is connected to the at least one exhaust valve, an exhaust cam follower that contacts the second cam, and an exhaust push pipe that connects the exhaust cam follower to the second tappet.

5. The system of claim 4, wherein in the second configuration of the first tappet and the second tappet, in response to the first cam cam angle and the second cam cam angle respectively contacting the intake cam follower and the exhaust cam follower, the intake pushrod and the exhaust pushrod are each allowed to translate relative to the first tappet and the second tappet, so that the at least one intake valve and the at least one exhaust valve remain closed.

6. The system of claim 4, wherein the first push rod and the second push rod each comprise: The outer body includes a collar that engages with a corresponding one of the first rocker arm and the second rocker arm; as well as The inner body is connected to one of the corresponding parts of the intake push pipe and the exhaust push pipe.

7. The system of claim 6, wherein in the first configuration, the inner body and the outer body of each of the first tappet and the second tappet are locked such that the intake push pipe and the exhaust push pipe act on and pivot on a corresponding one of the first rocker arm and the second rocker arm respectively through displacements generated by the first cam cam angle and the second cam cam angle, and in the second configuration, the inner body and the outer body of each of the first tappet and the second tappet are unlocked such that the displacements generated by the intake push pipe and the exhaust push pipe respectively through the first cam cam angle and the second cam cam angle are lost due to the displacement of the inner body within the outer body, and thus do not act on a corresponding one of the first rocker arm and the second rocker arm.

8. The system of claim 1, wherein the first tappet and the second tappet are received in a rocker arm housing, and the actuator is mounted to the rocker arm housing and extends through a cavity in the rocker arm housing to a position between the first tappet and the second tappet.

9. The system of claim 8, wherein the first tappet and the second tappet are in direct contact with corresponding portions of the first rocker arm assembly and the second rocker arm assembly housed in the rocker arm housing.

10. The system of claim 1, wherein the actuator includes a pin actuated to contact a radially extending arm of each of the first and second push rods, such that displacement of the pin causes a portion of each of the first and second push rods to rotate from the first configuration to the second configuration.

11. The system of claim 1, wherein each of the first push rod and the second push rod includes an inner body housed within an outer body, and in the first configuration, the inner body and the outer body are axially locked to prevent axial movement relative to each other, and in the second configuration, the inner body is rotated relative to the outer body, thereby axially unlocking the inner body and the outer body to allow axial movement relative to each other.

12. The system of claim 1, wherein the valve lift mechanism comprises: A first rocker arm, which is connected to the at least one intake valve and an intake cam follower that contacts the first cam and the first tappet; as well as The second rocker arm is connected to the at least one exhaust valve and the exhaust cam follower that contacts the second cam and the second tappet.

13. A tappet for modifying valve lift in a valve mechanism system for an internal combustion engine, comprising: An elongated inner body is housed within an outer body, wherein the inner body and the outer body include a locking configuration in which the inner body and the outer body are axially constrained relative to each other to provide a first valve lift in response to a cam lobe profile acting on the tappet, and the inner body and the outer body are axially rotated relative to each other to an unlocking configuration to provide a second valve lift in response to the cam lobe profile acting on the tappet, the second valve lift being less than the first valve lift.

14. The push rod of claim 13, wherein the inner body is spring-biased relative to the outer body toward the locking configuration.

15. The tappet of claim 13, wherein the outer body includes external teeth engaged by an actuator to rotate the outer body relative to the inner body.

16. The tappet of claim 13, wherein the outer body includes a collar extending outwardly therefrom for direct contact with the rocker arm of the valve mechanism assembly.

17. The push rod of claim 13, further comprising a shear pin engaged with the inner body and extending through the outer body, wherein in the locking configuration, the shear pin contacts the outer body to prevent axial movement of the inner body relative to the outer body, and in the unlocking configuration, the shear pin is aligned with an axially extending opening in the outer body to allow axial movement of the inner body relative to the outer body.

18. A valve mechanism system for an internal combustion engine, comprising: A rocker arm housing and at least one tappet positioned within the rocker arm housing, the at least one tappet being configured to operate in a first mode and a second mode, wherein in the first mode, the at least one tappet is configured to transmit a first valve lift in response to a cam cam profile acting on the at least one tappet, and in the second mode, the at least one tappet is configured to transmit a second valve lift less than the first valve lift in response to the cam cam profile acting on the at least one tappet.

19. The valve mechanism system of claim 18, wherein the at least one tappet comprises: An elongated inner body is housed within an outer body, wherein in a first mode, the inner body and the outer body are axially constrained relative to each other, and in a second mode, the inner body and the outer body rotate axially relative to each other, thus enabling the inner body and the outer body to move axially relative to each other.

20. The valve mechanism system of claim 19, further comprising an actuator mounted to the rocker arm housing, the actuator engaging the at least one tappet to cause the inner body and the outer body to rotate axially relative to each other.

21. The valve mechanism system of claim 18, further comprising a rocker arm in the rocker arm housing, the rocker arm being positioned around and in direct contact with the at least one tappet, wherein the at least one tappet pivots the rocker arm in response to valve lift.

22. A valve mechanism system for an internal combustion engine, comprising: A rocker arm and at least one tappet positioned in direct contact with the rocker arm for pivoting the rocker arm, the at least one tappet being configured to operate in a first mode and a second mode, wherein in the first mode, the at least one tappet is configured to transmit a first valve lift through the rocker arm in response to a cam lobe profile acting on the at least one tappet, and in the second mode, the at least one tappet is configured to transmit a second valve lift through the rocker arm in response to the cam lobe profile acting on the at least one tappet, the second valve lift being less than the first valve lift.

23. The valve mechanism system according to claim 22, further comprising: A rocker arm housing, wherein the at least one tap is positioned in the rocker arm housing, and the rocker arm is positioned about the at least one tap in the rocker arm housing.

24. A valve mechanism system for an internal combustion engine, comprising: Cam cap, which is used to engage with cylinder head, camshaft carrier or valve cover; And at least one tappet positioned within the cam cap for engaging a corresponding cam lobe angle, the at least one tappet being configured to operate in a first mode and a second mode, wherein in the first mode, the at least one tappet is configured to transmit a first valve lift in response to the cam lobe angle profile acting on the at least one tappet, and in the second mode, the at least one tappet is configured to transmit a second valve lift less than the first valve lift in response to the cam lobe angle profile acting on the at least one tappet.

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