A novel latch seat for a switching rocker arm assembly used in variable valve actuation (VVA) systems for internal combustion engines. The seat is formed interactively in the assembled switching rocker arm using a novel fixture and press. The press interactively creates a curved dimple of the correct curvature, position and depth while measuring several lash dimensions. Since the latch seat is formed on the assembled rocker arm assembly, the latch seat depth is designed to account for the inaccuracies in the rocker arm assembly parts which create lash. Therefore all of the parts may be made with less precision since the latch seat is sized to compensate for the inaccuracies of all of the parts. The rocker arm assembly parts now may be manufactured to less stringent standards, but result in a rocker arm assembly with same accuracy of rocker arm assemblies manufactured to previous standards.

A novel latch seat for a switching rocker arm assembly used in variable valve actuation (VVA) systems for internal combustion engines. The seat is formed interactively in the assembled switching rocker arm using a novel fixture and press. The press interactively creates a curved dimple of the correct curvature, position and depth while measuring several lash dimensions. Since the latch seat is formed on the assembled rocker arm assembly, the latch seat depth is designed to account for the inaccuracies in the rocker arm assembly parts which create lash. Therefore all of the parts may be made with less precision since the latch seat is sized to compensate for the inaccuracies of all of the parts. The rocker arm assembly parts now may be manufactured to less stringent standards, but result in a rocker arm assembly with same accuracy of rocker arm assemblies manufactured to previous standards.

An apparatus includes a ball plunger post and a valve stem post extending upward from a base, the ball plunger post having a size and a shape of a hydraulic lift adjuster (HLA) of a predefined engine, and the valve stem post having a size and a shape of a valve stem of the predefined engine. The apparatus includes a fixture sized and shaped to receive a switching rocker arm assembly, the switching rocker arm assembly having a first end for pivoting and a second end for latching, and a latch with a latch pin fitting into a latch bore and a latch seat. The apparatus includes a latch rod for positioning within the latch bore to rest upon the latch seat, the latch rod having a hardness higher than that of the latch seat and a same diameter as the latch pin, and adapted for coining the latch seat.

An adjustable camshaft for an internal combustion engine may have a support shaft that extends along a rotational axis; a cam pack having a cam element that is received on the support shaft such that the cam pack can be displaced along the rotational axis, wherein the cam pack can be latched on the support shaft in at least two axial latching positions; a latching element that is prestressed by way of a spring element; and a latching element receptacle disposed on the support shaft. The latching element can latch into the latching element receptacle in the latching positions. The spring element and the latching element may be received in the cam pack.

A multiple variable valve lift apparatus may include a first moving cam provided to rotate together with a camshaft and move in an axial direction of the camshaft, and configured to form a first cam guide protrusion and a plurality of cams realizing different valve lifts from each other, a second moving cam provided to rotate together with a second camshaft and move in an axial direction of the second camshaft, and configured to form a second cam guide protrusion and a plurality of cams realizing different valve lifts from each other, a first operating device operated to move the first moving cam in a first direction, a second operating device operated to move the second moving cam in a second direction, a controller configured to control operations of the first operating device and the second operating device, and a valve opening/closing device.

A switching rocker arm system includes a rocker assembly having a first end and a second end, and engaging a lash adjuster an and engine valve. The system further includes a first arm rotationally coupled to a second arm at the first or second end, and selectively rotationally coupled to the second arm at the other of the first end and the second end by a latch. In the latched position, a second cam engagement surface of the second arm engages the second cam to operate the engine valve in a high-lift mode, a biasing spring urges the second cam engagement surface into contact with the second cam, and a rotational stop prevents contact of the second cam engagement surface with a base circle portion of the second cam in the low-lift mode.

A method of precision manufacture of an outer arm of a rocker arm assembly is performed by determining structures of a rough outer arm that would require precision processing and locations to support the structures as they are processed. Starting with at least one structure requiring precision processing, locations on the outer arm close to the structure to hold the outer arm during processing are determined that would cause minimal distortion of the outer arm during processing. The outer arm is then provided with clamping lobes at these locations. The clamping lobes of the outer arm are clamping into a fixture for manufacturing. The slider pad may now be precision ground while the outer arm is clamped in the fixture with minimal risk of distortion of the outer arm.

A switching rocker arm having an outer arm having a first end, a second end, a first and second outer side arm having slider pads that ride on a second cam is disclosed. The switching rocker arm also has an inner arm disposed between the first and second outer side arms. The inner arm has a first end, a second end and a bearing disposed between the first and second end adapted to ride along a first cam. The inner arm is pivotably secured adjacent its first end to the outer arm adjacent its first end. At least one arm has an over-travel limiter structure limits pivoting motion of the first arm relative to the second arm. The switching rocker arm also exhibits decreased lash as the bearing wears, and increased lash as the latch and slider pads wear.

A valve train device for an engine includes: a shaft portion; a cam element portion which is mounted on the shaft portion; and an operation member. The cam element portion includes a first end surface cam and a second end surface cam. Each of the first end surface cam and the second end surface cam includes a lift portion. The operation member includes a first operation member and a second operation member. The first operation member causes the cam element portion to move in a first direction, and the second operation member causes the cam element portion to move in a second direction. The first end surface cam includes a first slope portion, and guides the first operation member radially outwardly; and a displacement allowing portion which is formed adjacent to the first slope portion, and allows relative displacement between the first operation member, and the cam element portion.

A cylinder deactivation arrangement and method of cylinder deactivation are disclosed for an internal combustion engine having a number of cylinders with at least one intake valve and at least one exhaust valve per cylinder. Each intake valve includes two different lifting levels, wherein the cylinder deactivation arrangement has an even number of cylinders. A first set of cylinders constituted by half of the even number of cylinders have intake valves configured for fully opened and partly opened lifting levels, and a second set of cylinders constituted by the other half of the even number of cylinders have intake valves configured for fully opened and closed lifting levels. The first set of cylinders have exhaust valves configured for fully opened lifting levels and the second set of cylinders have exhaust valves configured for fully opened and closed lifting levels.