A hydraulic oil control valve includes an outer sleeve, an inner sleeve and a spool. The outer sleeve includes: a threaded portion, which is fixed to a camshaft; a projection, which is fixed to a phase changer; and ports, which are formed at a peripheral surface of the outer sleeve between the threaded portion and the projection. The inner sleeve includes: ports, which are communicated with the ports of the outer sleeve; an oil port; an axial groove; and an enlarged diameter portion, which is located on one side of the projection where an insertion opening of the outer sleeve is placed. The spool includes: land portions, which are configured to slide along an inner peripheral surface of the inner sleeve and are located at an outer periphery of the spool at a location that is on another side of the projection where the threaded portion is placed.

A control valve (1) for a camshaft adjustment device, and to an internal combustion engine having a camshaft adjustment device and a control valve (1) is provided. The control valve (1) includes a valve housing (3) and a pressure medium guiding insert (23) arranged coaxially in a recess of the valve housing (3). A discharge passage (27, 28) of the pressure medium guiding insert (23) transitions into a discharge duct (22) running in the axial direction, wherein the discharge connection T can be connected to the control connection A, B and wherein the discharge connection T is arranged in a region between the second end (8), which is opposite the first end (6), and the control connections A, B.

A hydraulic fluid control valve (HFCV) configured to recirculate an existing hydraulic fluid from a first hydraulic actuation chamber to a second hydraulic actuation chamber is provided. The HFCV includes a selectively movable spool assembly having an outer annulus, at least one one-way valve arranged within the outer annulus, and 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. The at least one one-way valve moves in an axial direction and the outer annulus serves as an axial motion stop for the at least one one-way valve.

A hydraulic oil control valve includes a sleeve, a spool and a spring. The spool is received at an inside of the sleeve and is configured to be reciprocated. The spring is configured to be seated against a spring seat of the sleeve and is configured to apply a preload to the spool. The sleeve has a stepped portion, which has a spool contact surface for limiting movement of the spool toward the spring seat, and a protrusion, which is located at a center of the spring seat and protrudes toward an opening of the sleeve. The protrusion has a sloped peripheral surface. The protrusion is configured such that in a state where an end portion of the spring is not seated against the spring seat while the spring is placed adjacent to the spring seat, the end portion of the spring contacts the protrusion.

The disclosure relates to a vane type camshaft adjuster for a motor vehicle drive train. The camshaft adjuster having a stator, a rotor arranged such that it can rotate relative to the stator, working chambers formed between the stator and the rotor, each working chamber being divided into two sub-chambers by a radially projecting blade of the rotor, and a reservoir connected to the sub-chambers for storing hydraulic medium. The sub-chambers can be connected to a pump or a tank according to a switch position of a control valve of the camshaft adjuster. The control valve has a switch position in which a first sub-chamber of the two sub-chambers is connected to the tank and a second sub-chamber of the two sub-chambers is blocked from the pump.

A valve timing adjustment device includes a hydraulic oil control valve. The hydraulic oil control valve includes: an outer sleeve that is shaped in a tubular form and has a projection at an outer periphery of the outer sleeve; an inner sleeve that is located on an inner side of the outer sleeve; and a spool that is located at an inside of the inner sleeve. A reference-shape portion, which serves as a reference at a time of positioning the outer sleeve relative to the inner sleeve, is formed at an outer periphery of the projection. A seat surface of the projection, which fixes a vane rotor between the seat surface of the projection and an end portion of one of a drive shaft and a driven shaft, is shaped in a rotationally symmetric form that is rotationally symmetric around a rotational axis.

A hydraulic camshaft adjuster (1), in which the locking system (7, 8) includes a first and a second control element (7, 8). In order to approach the middle position easily, the first control element (7) has a first and a second switching position, wherein in the first switching position a fluidic connection between the hydraulic pump (P) and a first of the two sub-chambers (B) and a fluidic connection between the other, second sub-chamber (A) and the tank (T) can be established, and in the second switching position a fluidic connection between the hydraulic pump (P) and the second of the two sub-chambers (A) and a fluidic connection between the other, first sub-chamber (B) and the tank (T) can be established, and the second control element (8) is free from different switching positions and has no influence on the flow of hydraulic fluid.

A check valve is made of a resilient body wound in a ring form and is located in an annular flow passage. A displacement limiter includes: a limiter main body that is located on an outer side of the check valve and is configured to limit displacement of the check valve in a diameter increasing direction of the check valve; and a limiter flow passage that communicates between one side and the other side of the limiter main body in an axial direction to enable hydraulic oil to flow between the one side and the other side of the limiter main body through the limiter flow passage.

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 spring well that combines a hydraulic fluid received from a hydraulic fluid pressure source with a recirculated hydraulic fluid from the first hydraulic actuation chamber and delivers the combination to the second hydraulic actuation chamber.

An engine includes at least one cylinder, a first intake valve and a second intake valve associated with the cylinder, to control a flow of intake air from a first intake duct and a second intake duct, respectively. The two intake ducts communicate with a common intake manifold, so as to receive air at the same pressure. During the intake stage, in each cylinder operating cycle, initially an opening and closing movement of only the first intake valve is activated, while the second intake valve remains closed and, subsequently, an opening and closing movement of only said second intake valve is activated, while the first intake valve remains closed. In this way, the two air flows at the same pressure entering the cylinder give rise to a high turbulent kinetic energy, to the advantage of combustion efficiency and reduction of harmful exhaust emissions.