An electromagnetic valve including a solenoid to generate an electromagnetic force; a cylindrical member at least partially disposed in the solenoid and made from a non-magnetic material; a movable member configured to be moved in the cylindrical member in an axial direction of the valve based on the solenoid, the movable member including a restriction portion on one end side of the movable member; a plunger including one end portion located on the one end side and an opposite end portion located on an opposite end side of the movable member, the plunger being restricted in a movement thereof in a radial direction due to the opposite end portion disposed at the restriction portion. A movable amount of the movable member in the radial direction in the cylindrical member is less than a movable amount of the plunger in the radial direction relative to the restriction portion.

Disclosed herein is a check valve. The check valve includes a valve housing having upper and lower ends opened and having an inlet formed along the circumference of the valve housing, the inlet linked to a inlet fluid path, an upper cap coupled to seal up an open upper portion of the valve housing, a lower holder coupled to an open lower portion of the valve housing, having an outlet formed along the circumference of the lower holder, the outlet linked to a outlet fluid path, and having a guide hole in the lower portion of the lower holder, and a plunger installed to move up or down to selectively open or close an orifice while elastically supported by an elastic member supported by the lower holder, wherein the plunger comprises guides at upper and lower ends of the plunger to guide the plunger to make stable linear motion.

Disclosed herein is a check valve. The check valve includes a valve housing having upper and lower ends opened and having an inlet formed along the circumference of the valve housing, the inlet linked to a inlet fluid path, an upper cap coupled to seal up an open upper portion of the valve housing, a lower holder coupled to an open lower portion of the valve housing, having an outlet formed along the circumference of the lower holder, the outlet linked to a outlet fluid path, and having a guide hole in the lower portion of the lower holder, and a plunger installed to move up or down to selectively open or close an orifice while elastically supported by an elastic member supported by the lower holder, wherein the plunger comprises guides at upper and lower ends of the plunger to guide the plunger to make stable linear motion.

A piston-cylinder unit includes a piston delimiting at least one working chamber, in which a first seal for sealing at least one first working chamber is arranged either between the piston and cylinder or between a plunger connected to the piston and the cylinder. A second seal is arranged between the first seal and the first working chamber, and the piston-cylinder unit further includes a first channel arranged in the wall of the cylinder or in the piston, which joins the first seal and the second seal in the inner chamber of the cylinder. The first channel and/or a hydraulic line connected thereto may have a throttle device and/or a valve device. An electronic control and regulating device may have a diagnosis or monitoring function for a possible defect or failure of a seal. Multiple hydraulic devices may have such piston-cylinder units and respective control and such regulating devices.

A piston-cylinder unit includes a piston delimiting at least one working chamber, in which a first seal for sealing at least one first working chamber is arranged either between the piston and cylinder or between a plunger connected to the piston and the cylinder. A second seal is arranged between the first seal and the first working chamber, and the piston-cylinder unit further includes a first channel arranged in the wall of the cylinder or in the piston, which joins the first seal and the second seal in the inner chamber of the cylinder. The first channel and/or a hydraulic line connected thereto may have a throttle device and/or a valve device. An electronic control and regulating device may have a diagnosis or monitoring function for a possible defect or failure of a seal. Multiple hydraulic devices may have such piston-cylinder units and respective control and such regulating devices.

A hydraulic system is provided. The hydraulic system may include a fluid pressure source in fluid communication with a supply line, a return line in fluid communication with a tank, a hydraulic function having a workport, a first control valve having a first proportional solenoid, a second control valve having a second proportional solenoid, and a controller. The controller being configured to selectively energize the first proportional solenoid, the second proportional solenoid, or the first proportional solenoid and the second proportional solenoid to control a system pressure differential, defined between the return line and the workport, within a range that is defined by a sum of a first predefined range defined by the first control valve and a second predefined range defined by the second control valve.

The hydraulic pressure generating device includes a regulator (spool valve) formed by a cylinder body, a spool which slidably moves within the cylinder body, a pilot chamber in which a pilot pressure which is a hydraulic pressure moving the spool along in an axial direction is inputted and an output chamber out of which an output pressure which is a hydraulic pressure corresponding to the pilot pressure is outputted, wherein the hydraulic pressure generating device further includes a spool position obtaining portion which obtains a relative position of the spool relative to the cylinder body and a pilot pressure controlling portion which controls the pilot pressure based on the relative position obtained by the spool position obtaining portion.

The hydraulic pressure generating device includes a regulator (spool valve) formed by a cylinder body, a spool which slidably moves within the cylinder body, a pilot chamber in which a pilot pressure which is a hydraulic pressure moving the spool along in an axial direction is inputted and an output chamber out of which an output pressure which is a hydraulic pressure corresponding to the pilot pressure is outputted, wherein the hydraulic pressure generating device further includes a spool position obtaining portion which obtains a relative position of the spool relative to the cylinder body and a pilot pressure controlling portion which controls the pilot pressure based on the relative position obtained by the spool position obtaining portion.

An adjustable magnetic valve includes a magnet assembly and a guide sleeve in which a static component is arranged fixedly and a valve armature is arranged so as to be axially displaceable therein. The magnet assembly is pushed onto the static component and the guide sleeve. The static component forms an axial stop for the valve armature, which either forces a closing element into a valve seat or lifts the closing element from the valve seat depending on the direction in which the valve armature is driven. The valve armature and the static component are each formed as plastic components. The valve armature has a magnet receptacle that receives a permanent magnet, which is polarized in terms of its movement direction such that the permanent magnet is arranged within the magnet assembly regardless of the armature stroke.

An adjustable magnetic valve includes a magnet assembly and a guide sleeve in which a static component is arranged fixedly and a valve armature is arranged so as to be axially displaceable therein. The magnet assembly is pushed onto the static component and the guide sleeve. The static component forms an axial stop for the valve armature, which either forces a closing element into a valve seat or lifts the closing element from the valve seat depending on the direction in which the valve armature is driven. The valve armature and the static component are each formed as plastic components. The valve armature has a magnet receptacle that receives a permanent magnet, which is polarized in terms of its movement direction such that the permanent magnet is arranged within the magnet assembly regardless of the armature stroke.