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.

A circular hydraulic press reforms and resizes a chamber opening in a combustion chamber housing. The press comprises a bar having a U-shaped end and a pair of free ends. The press comprises a panel having a C-shaped edge, a mounting edge, and a pair of slotted edges. The U-shaped end of the bar and the C-shaped edge of the panel buttress the perimeter of the chamber opening. The slotted edges and a pair of tubes on the slotted edges slidably receive the free ends of the bar to enable displacement of the panel towards the bar. A disk having a predetermined annular shape and circumference positions in the chamber opening. A hydraulic piston displaces the C-shaped edge of the panel towards the U-shaped end of the bar to press the chamber opening against the disk, and thereby reform the disk to substantially the same shape and circumference as the disk.

A circular hydraulic press reforms and resizes a chamber opening in a combustion chamber housing. The press comprises a bar having a U-shaped end and a pair of free ends. The press comprises a panel having a C-shaped edge, a mounting edge, and a pair of slotted edges. The U-shaped end of the bar and the C-shaped edge of the panel buttress the perimeter of the chamber opening. The slotted edges and a pair of tubes on the slotted edges slidably receive the free ends of the bar to enable displacement of the panel towards the bar. A disk having a predetermined annular shape and circumference positions in the chamber opening. A hydraulic piston displaces the C-shaped edge of the panel towards the U-shaped end of the bar to press the chamber opening against the disk, and thereby reform the disk to substantially the same shape and circumference as the disk.

A method of assembling a switching rocker arm assembly having an inner arm, an outer arm and a latch. The method includes indenting an outer arm surface on the outer arm, the outer arm surface defining an arcuate aperture. An inner arm surface can be indented on the inner arm at an inner arm latch shelf. A latch can be positioned relative to the inner and outer arms.

A method of assembling a switching rocker arm assembly having an inner arm, an outer arm and a latch. The method includes indenting an outer arm surface on the outer arm, the outer arm surface defining an arcuate aperture. An inner arm surface can be indented on the inner arm at an inner arm latch shelf. A latch can be positioned relative to the inner and outer arms.

A base-material hole is formed in a connecting-rod base material. A coating layer is deposited on an inner peripheral surface of the base-material hole. The base-material hole 15 has a cylinder inner-surface portion of a constant inner diameter, formed in a central region in an axial direction, and a tapered inner-surface portion that is continuous with an axially outer side of the cylinder inner-surface portion and is radially enlarged in an axially outward direction. The coating layer has a first coating portion and a second coating portion deposited on the tapered inner-surface portion to adjoin the first coating portion and gradually increasing in material thickness in the axially outward direction.

A method of manufacturing a torque-transmitting component includes providing a flat blank to a transfer press having a plurality of stations and performing a plurality of pressing operations, in which the flat blank is formed into a cup shape, rough splines are formed on the cup shape, and the rough splines are further pressed to define smooth splines. The component includes a continuous smooth inner diameter defined by a punch of the transfer press and a plurality of smooth splines defined by a die of the transfer press. The minor diameter of the splines is not machined to form the splines.

A method of manufacturing a torque-transmitting component includes providing a flat blank to a transfer press having a plurality of stations and performing a plurality of pressing operations, in which the flat blank is formed into a cup shape, rough splines are formed on the cup shape, and the rough splines are further pressed to define smooth splines. The component includes a continuous smooth inner diameter defined by a punch of the transfer press and a plurality of smooth splines defined by a die of the transfer press. The minor diameter of the splines is not machined to form the splines.

Provided is a concentric camshaft and a method of manufacturing the same, in which at least one of a fixed cam and a rotatable cam is a sintered cam configured to fix the cam and an inner piece through diffusion bonding, capable of reducing a machining amount, simplifying a manufacturing process because a heat treatment process for improving cam surface hardness is unnecessary, and being applied to an engine having a small space because the weight is reduced through a weight-reducing structure of a surface of the cam and a width of the inner piece is reduced.