Methods and systems are provided for monitoring and controlling a cylinder valve deactivation mechanism. In one example, a method may include sending a lower command signal to a cylinder deactivation valve control (CDVC) system without actuating a cylinder valve transition, determining an impedance of a solenoid of the CDVC system while sending the lower command signal, and actuating the cylinder valve transition responsive to the determined impedance by sending a higher command signal to the CDVC system. In this way, the cylinder valve transition is performed when the impedance is high enough to prevent over-current.

A sliding camshaft and a method of manufacturing a lobe pack for a sliding camshaft are provided. The lobe pack is formed from a steel alloy having a carbon content in the range of 0.48-0.53 wt %. The lobe pack is heated to a predetermined austenitizing temperature that is below a carburizing temperature of the steel alloy for a time period at least long enough to heat the entire lobe pack to the predetermined austenitizing temperature. The lobe pack is quenched to a martempering temperature that is greater than a martensite start temperature and within 50 degrees Celsius of the martensite start temperature. The lobe pack is held at the martempering temperature for a martempering time period that is long enough to cool the entire lobe pack to the martempering temperature. The lobe pack may have a hardness in the range of 56 to 60 HRC throughout the lobe pack.

As an oil control valve controlling oil pressure of a first hydraulic pressure chamber and a second hydraulic pressure chamber formed inside of a first electric hydraulic valve (EHV) device and a second EHV device, respectively, which are driven by a first cam and a second cam and include lower parts to which a first valve and a second valve are respectively connected, the oil control valve includes: a body including a communication hole having a first end in communication with the first hydraulic pressure chamber and a second end in communication with the second hydraulic pressure chamber; a hollow lower frame formed or fixedly mounted at the lower end part of the body and having an upper part communicating with the communication hole and a lower part communicating with an oil gallery supplying oil by disposing an upper end height at an inner space of the communication hole; and a pin frame disposed between an actuator moving up and down and the lower frame so as to vertically penetrate the communication hole and in contact with or separated from the upper part of the lower frame, wherein one end and the other end of the communication hole are in communication when the pin frame and the lower frame are in contact.

A valve train device, in particular for an internal combustion engine, includes at least one camshaft which has at least one cam element with at least one multi-track cam. The cam element is provided to be axially displaced by a maximum displacement path. The valve train device further includes a limiting mechanism which is provided to limit in at least one operating state the displacement path of the cam element to a switching path of the switching operation.

An electro-mechanical variable valve mechanism includes a variable valve mechanism body, a latching pin arranged in front of the variable valve mechanism body, and an inner body arranged inside the variable valve mechanism body. The latching pin reciprocates in a longitudinal direction of the variable valve mechanism body and the inner body to latch the variable valve mechanism body and the inner body.

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 valve train device, particularly for an internal combustion engine, includes a camshaft, a cam element able to be displaced axially on the camshaft, and a mechanical displacement element which is provided on the camshaft for the purpose of axially displacing the cam element. The mechanical displacement element is provided to move the cam element by interaction with only a single contour of the cam element in a first and a second axial direction.

A variable valve device for an engine, may include a camshaft; a movable cam device fitted over the camshaft to be slidable in an axial direction of the camshaft, and configured such that cams with at least two different cam profiles and a guide protruding portion are disposed along the axial direction of the camshaft; at least one shaft groove linearly processed to have a predetermined cross-sectional shape in an external circumferential surface of the camshaft along the axial direction thereof; a cam groove provided in an internal circumferential surface of the movable cam device to communicate with the shaft groove; and an insertion member inserted into a communication space defined by the shaft groove and the cam groove such that a rotational displacement of the camshaft is transmitted to the movable cam device.

A system and method for sensing a camshaft barrel position of a sliding camshaft includes at least one sliding camshaft having at least one camshaft barrel and at least one position shifting slot disposed in the at least one camshaft barrel. At least one actuator is provided for engaging the at least one position shifting slot on the rotating sliding camshaft and shifting position of the at least one camshaft barrel and at least one sensor is provided for detecting the shifted position of the at least one camshaft barrel wherein the camshaft barrel includes position identifying features.

A variable valve device for an engine, may include a camshaft; a movable cam device fitted over the camshaft to be slidable in an axial direction of the camshaft, and configured such that cams with at least two different cam profiles and a guide protruding portion are disposed along the axial direction of the camshaft; at least one shaft groove linearly processed to have a predetermined cross-sectional shape in an external circumferential surface of the camshaft along the axial direction thereof; a cam groove provided in an internal circumferential surface of the movable cam device to communicate with the shaft groove; and an insertion member inserted into a communication space defined by the shaft groove and the cam groove such that a rotational displacement of the camshaft is transmitted to the movable cam device.