A camshaft for a multiple-cylinder internal combustion engine may include a sliding element comprising at least two cam elements, as well as a splined shaft that extends in an axial direction and on which the sliding element is received. The sliding element may comprise an internal spline system that interacts with an external spline system of the splined shaft such that the sliding element is seated fixedly on the splined shaft so as to rotate with the splined shaft. The sliding element may be received on the splined shaft such that the sliding element can, at least initially, be displaced axially. For axially-fixing the sliding element to the splined shaft, the sliding element may include a positively locking connection that is configured in the axial direction and is produced by way of at least one calked connection between the sliding element and the splined shaft. It should be understood that many camshafts include more than one sliding element.

A camshaft is equipped with an inner shaft which is arranged rotatably inside a cylindrical outer shaft. Further, in the inner shaft, a plurality of pin holes extend along diametrical directions thereof, and are disposed at intervals along the axial direction of the inner shaft. The directions in which adjacent pin holes extend are arranged at angles obtained by dividing 360 degrees by the number of cylinders. The inner shaft and the inner cams are fixed in a state in which large diameter portions of pins, each of which is provided with a small diameter portion and a large diameter portion, are press-fitted through insertion holes of the inner cams and notches of the outer shaft, and are press-fitted into the pin holes.

Provided is a heat treatment method for a cam piece, and the cam piece has an insertion hole into which a cam shaft is inserted, a base portion configuring a base circle of a cam, and a nose portion configuring a cam ridge. The heat treatment method for the cam piece includes: a first step of using a jig formed into a shape having a cavity, the jig being inserted into the insertion hole such that the cavity is located between an inner circumferential surface of the nose portion of the cam piece and a central axis of the jig; and a second step of heating the cam piece from an outer circumferential surface side by high-frequency induction heating in a state in which the jig is inserted in the insertion hole of the cam piece.

A method for assembling a camshaft from a support shaft and components to be connected to the support shaft, the components having through-openings for receiving the support shaft. In this method, a support shaft is provided, having first diametrical enlargements in first regions, in which the components are to be secured, and second diametrical enlargements in second regions, in which the components are to be pre-positioned. A diameter (D2) in the second regions is smaller than a diameter (D1) in the first regions The support shaft is cooled and/or the components are heated up, so that the support shaft can be pushed with its first and second diametrical enlargements through the through-openings of the components.

A multi-tubing pinch valve assembly including a receiving space defined between a pinch protrusion and tubing contact body. The multi-tubing pinch valve assembly is moveable between a retracted state and an extended state. In the extended state, multiple tubes disposed in the receiving space are pinched, restricting flow therethrough. In the retracted state, multiple tubes are capable of being loaded into and/or out of the receiving space.

A hydraulic fluid control valve (HFCV) configured to recirculate an exiting hydraulic fluid from a first hydraulic actuation chamber to a second hydraulic actuation chamber is provided. The HFCV includes a selectively movable spool having an inner fluid chamber configured to receive and deliver the exiting hydraulic fluid to one or both of either a sump or one of the first or second hydraulic actuation chambers.

A multi-tubing pinch valve assembly including a receiving space defined between a pinch protrusion and tubing contact body. The multi-tubing pinch valve assembly is moveable between a retracted state and an extended state. In the extended state, multiple tubes disposed in the receiving space are pinched, restricting flow therethrough. In the retracted state, multiple tubes are capable of being loaded into and/or out of the receiving space.

A method for producing a constructed camshaft of an internal combustion engine may be used in connection with a camshaft having a cam, a shaft, and an anti-friction bearing. The method may involve machining the cam, machining the shaft to produce a setting region for arranging the cam, heating the cam and the anti-friction bearing, pushing the cam onto the shaft into a preliminary position and pushing the anti-friction bearing onto the shaft into a bearing position, equalizing a temperature between the shaft, the cam, and the anti-friction bearing by cooling at least the cam, and setting the cam onto an end position by way of pushing the cam onto the setting region.

A camshaft and method of producing a camshaft for an internal combustion engine. The camshaft includes a base shaft and an external toothing extending at least in certain portions axially along the base shaft. The camshaft includes a hub with an internal toothing which correlates with the external toothing of the base shaft such that the hub is connected rotationally conjointly and axially non-displaceably to the base shaft. The external toothing has at least one form-fit subregion that extends axially at least in certain portions along the base shaft, or one force-fit subregion in order for the hub to be arranged at least in a form-fitting or force-fitting manner. At least the form-fit subregion or the force-fit subregion is adjoined by at least one alignment region which extends at least in certain portions axially along the base shaft and which serves for the angular alignment of the hub.

A camshaft for an engine and a method of assembling such a camshaft, wherein the camshaft has a base shaft and an external toothing which extends at least in certain portions axially along the base shaft A hub has an internal toothing which correlates with the external toothing of the base shaft such that the hub is connected rotationally conjointly and axially non-displaceably to the base shaft. The external toothing has at least one form-fit subregion, which extends axially at least in certain portions along the base shaft, or one force-fit subregion in order for the hub to be arranged at least in a form-fitting or force-fitting manner, and wherein at least the form-fit subregion or the force-fit subregion is adjoined by at least one alignment region which extends at least in certain portions axially along the base shaft and which serves for the angular alignment of the hub.