Abstract: A rocker arm assembly includes an inner rocker arm and an outer rocker arm. The outer rocker arm includes two rail portions spaced a distance apart and forming an open space therebetween. The inner rocker arm is pivotably connected to the outer rocker arm such that it is at least partially within the open space. The inner rocker arm includes a locking pin housing containing two locking pins selectively engageable with holes in each of the rail portions to selectively prevent relative movement between the inner rocker arm and the outer rocker arm. The rocker arm assembly enables two-step valve operation and has a design characterized by compact size and improved manufacturability.

Abstract: A valve system has a piston mounted in a cylinder in one of first and second rocker arms and is adapted to be forced by a return spring, and an engagement projection formed in the other one of the first and second rocker arms and is adapted to abut the piston to cause both of the first and second rocker arms to move in conjunction with each other. The return spring is disposed eccentrically with respect to the piston in such a direction as to get away from the engagement projection. Therefore, it is possible to ensure a sufficient stiffness of a power transmitting section of the valve system and a sufficient valve lift.

Abstract: A roller rocker mounting mechanism for an internal combustion engine valve actuating mechanism includes a first rocker stand having a first locating boss and a second rocker stand having a second locating boss. An indexing link has a first portion separably attachable to the first locating boss and a second portion separably attachable to the second locating boss to connect the first rocker stand and the second rocker stand in a manner that prevents rotation of either rocker stand when the rocker stands are attached to the cylinder head.

Abstract: A valvetrain with a single camshaft is disclosed. The valvetrain has one or more intake valves, and one or more exhaust valves per cylinder of an engine block. The valvetrain comprises a cylinder head. The valve head of each intake valve is removably seated within a corresponding intake valve seat of the cylinder head, and the stem of each intake valve is movably positioned within the cylinder head. The valve head of each exhaust valve is removably seated within a corresponding exhaust valve seat of the cylinder head, and the stem of each exhaust valve is movably positioned with the cylinder head. For each cylinder, an intake crosshead and an exhaust crosshead are pivotally mounted upon the cylinder head. Each intake crosshead is operatively mounted upon the stem top of a corresponding intake valve. Each exhaust crosshead is operatively mounted upon the stem top of a corresponding exhaust valve. For each cylinder, an intake rocker arm and an exhaust rocker arm are pivotally coupled to the cylinder head.

Abstract: What is proposed is a lever-type cam follower (1) made of sheet metal, typically for a valve train of an internal combustion engine, said cam follower (1) comprising two parallel side walls (3a, 3b) connected by a crossbeam (2), an underside (4) of the crossbeam (2) having a support (6) for at least one gas exchange valve on one end (5), said support (6) being limited by guide walls (7a, 7b) extending parallel to the side walls (3a, 3b), wherein the one end (5) of the cam follower (1) is narrower than the rest of the length of the cam follower (1), and at least in the region of said one end (5), the side walls (3a, 3b) have a smaller mean wall thickness (DSM) than over the rest of said length, which wall thickness (DSM) increases at least in said region continuously from ends (8a, 8b) of the side walls (3a, 3b) in the direction of the crossbeam (2), and the thickness (DF) of the guide walls (7a 7b) is smaller than the mean wall thickness (DSM) in the region of the narrow one end (5).

Abstract: To provide a valve system for an engine, in which a rocker arm is interlocked with an engine valve and is supported on a rocker shaft fixedly mounted to a cylinder head such that it is rockable with the rotation of a camshaft. Accordingly, the size and weight of the engine can be reduced. The posture of a rocker shaft is set to have an axial line crossing an axial line of a crankshaft on the projection plane perpendicular to an axial line of a cylinder bore. A rocker arm is rockably supported by the rocker shaft and is provided with an input arm extending, on the above projection plane, from the rocker arm to the camshaft side. A pull rod reciprocates in the axial direction with the rotation of the camshaft and is connected to the input arm.

Abstract: The present invention relates to an internal combustion engine operating on spark-ignitible fuel, featuring at least one operating mode with homogeneous charge and self-ignition, and comprising at least one intake valve and at least one exhaust valve per cylinder, which intake and exhaust valves may be coupled via a transmission device in at least one operating mode of the engine. The combustion process may be controlled in a simple manner by providing that at least one exhaust valve can be actuated during the intake stroke by means of the transmission device, said transmission device having at least one first mechanical transmission member, and that the transmission device can be activated by a mechanical actuating device, said actuating device featuring an eccentric element acting on a transmission member.

Abstract: A valve-operating device for an engine includes a camshaft which is disposed on one side of a plane including axes of an exhaust valve and an intake valve and which has an axis substantially perpendicular to the plane. The camshaft and the exhaust and intake valves are connected to each other through a first rocker arm and a second rocker arm which are swingably carried on a rocker shaft disposed substantially perpendicular to the plane. The camshaft is formed with a large-diameter exhaust cam and a small-diameter intake cam adjoining a portion of the exhaust cam on the side of the plane. The exhaust and intake rocker arms are provided with arm portions extending in an axial direction of the camshaft to come into sliding contact with outer peripheral surfaces of the exhaust and intake cams, respectively. Thus, it is possible to open and close the exhaust and intake valves with inherent opening and closing timings, while easily avoiding interferences among components.

Abstract: A sheet metal rocker arm manufactured by the steps of punching one metal plate to form a blank having a predetermined contour and through holes, and subjecting this blank to a bending work based on a press work to form a pair of side walls parallel to each other and a connecting portion for connecting the both ends of the side walls in the width direction thereof. This rocker arm is also provided with at least a pair of though holes formed at positions which are aligned with each other on the both side walls and at least one engagement portion provided in a part of the connecting portion. The thickness of at least one engagement portion, is formed to be greater than the thickness of the both side walls.

Abstract: An outboard motor includes an internal combustion engine provided with a pair of intake valves. The opening and closing operation of one of the intake valves can be paused. The internal combustion engine comprises a vertical crankshaft, a cylinder head provided with an intake port having a pair of intake openings for one combustion chamber, and a fuel injection valve for injecting the fuel into the intake port. The intake port has an upper branch section and a lower branch section extended under the upper branch section. A valve train includes a valve-operation mode changing mechanism. The valve-operation mode changing mechanism pauses the opening and closing operation of the first intake valve and operates the second intake valve for opening and closing the lower intake opening of the lower branch section while the internal combustion engine is operating at engine speeds in a low-speed range.

Abstract: A Variable valve lift mechanism that minimizes the number of components and also which permits a greater latitude of valve lift adjustment including the possibility of no valve lift under some running conditions. This is done without interference with other components of the engine and thus permits a compact engine assembly.

Abstract: The present invention is directed to a rocker arm having a pivoting clevis mounted to a second end of the rocker arm that engages a valve stem or a bridge that activates dual valves. The clevis has a substantially flat contacting surface and an internal recess created by two upwardly extending walls and an upwardly facing cam surface or receiving the second end of the rocker arm. The clevis is attached to the second end of the rocker arm by an attachment pin that extends through the upwardly extending walls of the clevis and through the second end of the rocker arm. The second end of the rocker arm has a downwardly extending portion that mates with the upwardly facing cam surface of the clevis to allow the clevis to pivot about the attachment pin.

Abstract: An actuator for adjusting a clearance between an end of a valve and an end of the actuator. The actuator has a piston therein having a central bore of which a portion is threaded. The piston has an end and has a flat defined near the end. The actuator has a stem member positioned therein. The stem member has a central portion which is threadedly positioned within the threaded portion of the central bore. The stem member defines a first end and a second end, and a threaded portion is located near the second end. The first end of the stem member and the end of the piston has a predetermined length which is adjustable. The predetermined length is adjusted by threadedly rotating the stem member relative to the piston. A locking device fixes the predetermined length during operation of the engine.

Abstract: A low speed cam is disposed on a cam shaft. A low speed sub-rocker arm actuated by the low speed cam is pivotally connected to a main rocker arm. A connecting member is supported by the main rocker arm. The connecting member has both a first condition wherein the sub-rocker arm and the main rocker arm are fixed to each other to constitute a single unit and a second condition wherein the sub-rocker arm and the main rocker arm are disengaged from each other. A hydraulically actuating mechanism has a hydraulic work chamber. The mechanism induces the first condition of the connecting member upon discharge of hydraulic fluid from the work chamber and induces the second condition upon feeding of hydraulic fluid to the work chamber. A control unit causes the hydraulically actuating mechanism to induce the first condition of the connecting member when the engine stops.

Abstract: In a valve operating system in an internal combustion engine, a swinging support section provided at a base end of a rocker arm is swingably carried on a rocker shaft mounted in a cylinder head. A plurality of valve abutments are provided at a tip end of the rocker arm and capable of being individually put into abutment against upper ends of a plurality of engine valves, and a cam abutment is provided on the rocker arm in an intermediate portion between the swinging support section and each of the valve abutments to come into contact with a valve operating cam. The swinging support section comprises a thinner cylindrical portion surrounding the rocker shaft, and thicker cylindrical portions which are formed at a thickness larger than that of the thinner cylindrical portion into a cylindrical shape to surround the rocker shaft and which are integrally and continuously provided at axially opposite ends of the thinner cylindrical portion, respectively.

Abstract: In an internal combustion engine, a pair of suction ports are formed on left and right sides of the rear of the cylinder head with respect to the vehicle body. A pair of exhaust ports is formed on left and right sides on the front side of the cylinder head. Suction poppet valves and exhaust poppet valves for opening and closing the suction ports and the exhaust ports are slidably fitted in guide tubes, respectively. In addition, a valve gear includes a camshaft and a rocker arm pivotally supported on a rocker arm shaft. The rocker arm is formed with a bifurcated end, which crosses an ignition plug on the exhaust poppet valve side. The suction poppet valves are directly driven to open and close by the camshaft.

Abstract: In a valve operating system in an internal combustion engine, a swinging support section provided at a base end of a rocker arm is swingably carried on a rocker shaft, and tappet screws are threadedly fitted in a plurality of boss portions formed at a tip end of the rocker arm and arranged in a direction parallel to an axis of the rocker shaft, so that they can be individually put into abutment against upper ends of a plurality of engine valves. Cam abutments are provided on the rocker arm in an intermediate portion between the swinging support section and the boss portions to come into contact with a valve operating cam. The boss portions are interconnected by a connection wall having a plurality of wall portions which intersect each other in a plane perpendicular to the axis of the rocker shaft. Thus, the rigidity of the tip end of the rocker arm is enhanced sufficiently.

Abstract: In a valve operating system in an internal combustion engine, a rocker arm has a plurality of valve abutments provided thereon and capable of being individually put into abutment against upper ends of a plurality of engine valves cam abutments, and also has cam abutments provided thereon to come into contact with a valve operating cam. Wall-removed portions are formed in the rocker arm at locations corresponding to the cam abutments and open at opposite sides of the rocker arm. Thus, it is possible to provide a reduction in weight of the rocker arm.

Abstract: A valvetrain with a single camshaft is disclosed. The valvetrain has one or more intake valves, and one or more exhaust valves per cylinder of an engine block. The valvetrain comprises a cylinder head. The valve head of each intake valve is removably seated within a corresponding intake valve seat of the cylinder head, and the stem of each intake valve is movably positioned within the cylinder head. The valve head of each exhaust valve is removably seated within a corresponding exhaust valve seat of the cylinder head, and the stem of each exhaust valve is movably positioned with the cylinder head. For each cylinder, an intake crosshead and an exhaust crosshead are pivotally mounted upon the cylinder head. Each intake crosshead is operatively mounted upon the stem top of a corresponding intake valve. Each exhaust crosshead is operatively mounted upon the stem top of a corresponding exhaust valve. For each cylinder, an intake rocker arm and an exhaust rocker arm are pivotally coupled to the cylinder head.

Abstract: A valve drive mechanism includes a tappet assembly which comprises a center tappet, a pair of side tappets between which the center tappet is interposed so as to move relatively to the side tappets, and a locking/unlocking mechanism operative to mechanically couple the center tappet to both of the side tappets and to uncouple the center tappet from both of the side tappets so as to selectively transmit rotation of a high lift center cam and low lift side cams to twin valves such as twin intake valves and twin exhaust valves per cylinder. Locking/unlocking of the center tappet and each side tappet is performed in a position which is in a vertical plane including a center axis of each side tappet and intersecting perpendicularly to an axial direction of a camshaft and is offset from the center axis of the side tappet.

Abstract: There is provided a rocker arm assembly for mounting on a carrier in an internal combustion engine that can be pre-assembled and installed on the rocker carrier decreasing manufacturing time and cost. The rocker arm assembly comprises a rocker arm, a fulcrum plate, a retaining clip, and a pivot ball that in cooperation with the retaining clip cooperatively connects the fulcrum plate and the rocker arm such that the pivot ball provides a pivot point for the rocker arm to pivot and thereby actuate at least one valve or valve bridge. The rocker arm further comprises a push rod cup, an aperture, pivot ball cup, and a pivot foot. The fulcrum plate can be a dual fulcrum plate, which holds two rocker arms, or an end fulcrum plate, which holds one rocker arm. The rocker arms can be either intake or exhaust rocker arms.

Abstract: A rocker arm assembly for an engine is disclosed. The rocker arm assembly comprises a rocker shaft having a first side and a second side and a rocker arm pivotably disposed on the rocker shaft. The rocker arm comprises a first portion disposed on the first side of the rocker shaft for receiving a force in a first direction from a brake actuator. The rocker arm further comprises a second portion disposed on the second side of the rocker shaft for engaging a valve in a second direction opposite the first direction. When the braking mode is desired, the brake actuator forces the first portion of the rocker arm in a first direction causing the rocker arm to transfer motion from the brake actuator to the exhaust valve or valves, thereby allowing exhaust to exit the combustion chamber.

Abstract: An internal combustion engine includes a housing with a plurality of combustion cylinders. At least one of the combustion cylinders has a longitudinal axis which is disposed at an acute angle relative to a longitudinal axis of at least one other combustion cylinder. A camshaft is rotatably carried by the housing and includes a plurality of cams. A plurality of lever lifter assemblies are associated with respective ones of the combustion cylinders. Each lever lifter assembly includes an intake lever lifter, an exhaust lever lifter and a fuel injector lever lifter. Each of intake lever lifter, exhaust lever lifter and fuel injector lever lifter has a roller follower engaging a respective cam. A pivot shaft carried by the housing pivotally carries at least one lever lifter assembly associated with the at least one combustion cylinder and also pivotally carries at least one lever lifter assembly associated with the at least one other combustion cylinder.

Abstract: A rocker arm (10) that reduces frictional forces between a cam (86) and the rocker arm (10) is disclosed. The rocker arm (10) includes a pair of spaced side members (20) having a valve portion (14), a middle portion (16), and a pivot portion (12). The side members (20) of rocker arm (10) each define a downwardly extending tappet hole (49) located generally centrally within the valve portion (14). The middle portion (16) of each side member (20) defines a bearing hole (68), and each of the pivot portions (12) defines a pivot hole (66). A web (70) extends between side members (20) at a valve portion (14) and at the pivot portion (12), defining a recess (85) therebetween at about the middle portion (16). A pin bearing is located within the bearing holes (68) and passes through the recess (85). An annular striking member (80) is located within the recess (85) and rotatably engages the pin bearing (69). During operation, a cam (86) is placed in operative contact with striking member (80).

Abstract: A valve drive arrangement for use in an engine having a pair of intake valves and a pair of exhaust valves for each cylinder. Each pair of intake valves are coupled to each other by a valve bridge and forced downwards simultaneously by a single rocker arm, and each pair of exhaust valves are coupled to each other by another valve bridge and forced downwards simultaneously by another single rocker arm. A contact member is rotatably provided on an upper surface of each valve bridge such that it contacts the associated rocker arm. The press center of the rocker arm to the associated contact member and center lines of the associated valves lie in a single plane. A rotation center of the associated contact member is offset from this single plane.

Abstract: The invention relates to a multicylinder internal combustion engine with two inlet valves and two outlet valves (12, 11), the outlet valves (11) being located on one side of an internal combustion engine and the inlet valves (12) being located on the other side. The outlet valves (11) and the inlet valves (12) are actuated by a camshaft via inlet rocker arms (4) and outlet rocker arms (5). In order to reduce the size of the cylinder heads (1) and the rocker housing (2), the inlet rocker arm (4) and the outlet rocker arm (5) are forked. Each forked rocker arm (4,5) actuates two similar valves (12,11) per cylinder (13). The axes (4a, 5a) of the inlet rocker arms (4) or outlet rocker arms (5) are staggered in relation to each other or preferably overlap.