Shown is a latch pin for use in a valve lifter and a valve lifter including the same. The latch pin for selectively latching within a pin chamber provided in the valve lifter is configured as a whole as a cylindrical pin with one end in the shape of a spherical crown, wherein a stepped flat is formed on radially one side of said one end and is dimensioned to be received within the pin chamber to engage with an axial latching surface thereof. On the top side of said one end, a first relief is formed by beveling the spherical crown, and on the radially other side opposite to the stepped flat across said first relief, a second relief is formed by beveling the spherical crown, wherein the second relief radially adjoins the first relief and circumferentially adjoins a remaining pin face in the shape of the spherical crown.

A vehicle includes a variable displacement engine and a controller. The variable displacement engine has a plurality of cylinders and is configured to operate at a commanded air-fuel ratio. The controller is programmed to, in response to a command to perform a diagnostic test, operate the engine such that each of the cylinders is shut down for a portion of the diagnostic test while one or more of the remainder of the cylinders remain operating. The controller is further programmed to, in response to a deviation from the commanded air-fuel ratio exceeding a threshold while a first of the cylinders is shut down during the diagnostic test and a subsequent command to decrease the number of operating cylinders, shut down one or more of the plurality of cylinders other than the first of the cylinders.

Systems and methods for opening and closing exhaust poppet valves of an engine are disclosed. In one example, the exhaust poppet valves may be opened and closed twice during a cycle of an engine via two serially arranged cam lobes that are coupled to a crankshaft so that hydrocarbons may be retained in a cylinder.

In order to ensure a simple, reliable and recuperative operation in a hydraulic drive (10) for accelerating and braking a gas exchange valve (20) of internal combustion engines or other reciprocating engines, it is proposed that a first pressure reservoir (41) for providing a first pressure p.sub.1 comprises a restoring energy accumulator, preferably configured as a spring (25), and at least one hydraulic base pressure reservoir (40), which has a lower pressure p.sub.0 than the first pressure reservoir (41). In a connecting line (48) between the first hydraulic pressure reservoir (41) and the working cylinder (22), a controllable opening (49) of a first valve (46) comprising at least one check valve (47) is arranged upstream or downstream in the flow path, which allows the pressure medium (30) to flow in the direction of working cylinder (22), but prevents a backflow towards the pressure reservoir (41).

In order to also initiate the closing movement or to enable the breaking of the gas exchange valve in a hydraulically simple and reliable manner, in a second connecting line (58) between the first pressure reservoir (41) and the working cylinder (22) there is arranged a controllable opening (59) of a second valve (56) comprising a check valve (57), which prevents a flow in the direction of the working cylinder (22), but allows a return flow in the direction of the pressure reservoir (41).

An internal combustion engine includes a cylinder including a piston connected to a rotatable crankshaft, an air guide arranged to guide an air flow to the cylinder an adjustable air flow restriction element arranged to restrict the How through the air guide, an exhaust guide being arranged to guide a gas flow from the cylinder, an adjustable exhaust flow restriction element arranged to restrict the flow through the exhaust guide, an exhaust valve arranged to control a communication between the cylinder and the exhaust guide, and an exhaust valve actuation assembly for actuating the exhaust valve so as to perform in each of a plurality of cycles of the cylinder an exhaust valve actuation sequence, wherein the exhaust valve actuation assembly is adapted to control the commencement of the exhaust valve actuation sequence to occur selectively at any crankshaft angle within a non-zero crankshaft angle interval.

Systems for valve actuation in internal combustion engines provide configurations for collapsing valve train components, particularly collapsing valve bridges. Various configurations for locking a bridge piston to a bridge housing include substantially cylindrical locking pins that may be housed within a substantially cylindrical receptacles defined by a transverse bore in the bridge piston and actuated hydraulically and may include an actuating pin that interacts with the locking pins to synchronize motion and provide positive positioning within an annular recess in the bridge housing to lock or unlock the bridge piston for movement relative to the bridge housing. Various geometries for locking pins and actuating pins provide benefits of manufacturing, ease of assembly, alignment and reduced wear.

The invention relates to a valve-actuating device (1) for actuating at least one first valve of a reciprocating piston machine, in particular an internal combustion engine, which valve-actuating device can be used in particular for engine braking and comprises a first rocker arm part (2), a second rocker arm part (3), and a first switching element (6) for changing the valve stroke (H) of the at least one first valve (5), wherein the first rocker arm part (2) and the second rocker arm part (3) are pivotably supported and are arranged in such a way that at least one first valve control motion of a first camshaft (4) can be transmitted to the at least one first valve (5) by means of the first rocker arm part (2) and the second rocker arm part (3).

A control device for an internal combustion engine is configured to: execute a first decompression operating processing such that a decompression operating state is selected in a first engine speed region that passes in the course of engine stop; execute a decompression stop processing such that a switching from the decompression operating state to a decompression stop state is performed in the course of the engine stop after passage of the first engine speed region; when a temperature correlation value is greater than or equal to a threshold value upon an engine start-up request, execute a second decompression operating processing such that the decompression operating state is selected in a second engine speed region that passes in the course of engine start-up before the start of fuel injection. When the temperature correlation value is smaller than the threshold value, the second decompression operating processing is not executed.

An actuation arrangement for actuating a plurality of latching arrangements of a respective plurality of dual body rocker arms of a valve train assembly of an internal combustion engine includes: a first shaft comprising one or more first selector cam for controlling the latching arrangements of a first group of one or more of the dual body rocker arms; and a second shaft comprising one or more second selector cams for controlling the latching arrangements of a second group of one or more of the dual body rocker arms. At least a portion of the first shaft is received in the second shaft, and the first shaft and the second shaft are controllable to rotate independently of one another, thereby to allow control of the latching arrangements of the dual body rocker arms on a per group basis.

An engine brake rocker arm assembly is operable in an engine drive mode and an engine braking mode and selectively opens first and second exhaust valves. The engine brake rocker arm assembly includes an exhaust rocker arm configured to rotate about a rocker shaft, an engine brake capsule assembly movable between (i) a locked position configured to perform an engine braking operation, and (ii) an unlocked position that does not perform the engine braking operation, and a hydraulically controlled actuator assembly configured to selectively move the engine brake capsule assembly between the first and second positions.