In a diameter-increasing portion, which includes first to third angle segments, an A-point is defined as an intersection between a radially outer surface of a thin wall portion and the first angle segment, and a B-point is defined as an intersection between a radially outer surface of a thick wall portion and the third angle segment. Radially outer surfaces of the first to third angle segments are located on a radially outer side of a reference conical surface, which is formed by rotating a straight line connecting between the A-point and the B-point about a central axis, throughout an entire range from the A-point to the B-point. A first angle , a second angle , a third angle and a reference angle satisfy relationships of , , >, and >.

In a diameter-increasing portion, which includes first to third angle segments, an A-point is defined as an intersection between a radially outer surface of a thin wall portion and the first angle segment, and a B-point is defined as an intersection between a radially outer surface of a thick wall portion and the third angle segment. Radially outer surfaces of the first to third angle segments are located on a radially outer side of a reference conical surface, which is formed by rotating a straight line connecting between the A-point and the B-point about a central axis, throughout an entire range from the A-point to the B-point. A first angle , a second angle , a third angle and a reference angle satisfy relationships of , , >, and >.

An electromagnetic positioning device (1), having a stationary spool unit (9), having a moveably guided anchor (2), which forms a positioning section (14) and which can be axially displaced along a displacement axis (V) in response to supplying the spool unit (9) with current, as well as having a one-part cup-shaped yoke-core element (3), which receives the anchor (2) and which includes a core section (5) as well as a yoke section (6) and which has a yoke-core bottom (4) extending perpendicular to the displacement axis (V) and a yoke-core sheath extending perpendicular to the yoke-core bottom (4) along the displacement axis (V), a longitudinally cut transition area (8) reduced in thickness and arranged between the core section (5) and the yoke section (6) being realized in the yoke-core sheath. It is intended that a guide pin (17) for the anchor (2) is fixed, preferably pressed in, in a, preferably centric, guide pin recess (18) in the yoke-core bottom (4) and protrudes axially into a, preferably centric, guide opening (13) of the anchor (2) and can be displaced relative to the anchor (2) during its displacement movement.

An electromagnetic actuator includes an armature which has a stop face, and a pole piece which has a counter stop face, wherein the stop face and the counter stop face in terms of geometry are configured so as to be mutually complementary such that the stop face and the counter stop face in a movement of the armature toward the pole piece engage in one another, displacing a medium which is disposed between the stop face and the counter stop face. An electromagnetic valve may include the electromagnetic actuator, and a high-pressure fuel pump may include the electromagnetic valve.

An electromagnetic actuator includes an armature which has a stop face, and a pole piece which has a counter stop face, wherein the stop face and the counter stop face in terms of geometry are configured so as to be mutually complementary such that the stop face and the counter stop face in a movement of the armature toward the pole piece engage in one another, displacing a medium which is disposed between the stop face and the counter stop face. An electromagnetic valve may include the electromagnetic actuator, and a high-pressure fuel pump may include the electromagnetic valve.

An electromagnetic valve, having a valve closing element which is arranged in a valve housing and which is capable of opening or closing a valve passage in a valve seat, having a magnet armature provided for actuating the valve closing element, and having a substantially cylindrical restoring spring which is braced between the magnet armature and a magnet core. In a parallel arrangement with respect to the restoring spring, a spring ring is arranged between the magnet armature and the magnet core, which spring ring has a smaller number of spring windings in relation to the number of spring windings of the restoring spring.

A device and a method are provided for determining a stroke of an armature of a magnetic valve which has a coil and the armature is displaceable by magnetic force, including: providing at least one reference data set which includes a magnitude of a current through the coil and a magnitude of the magnetic flux in the case of a known magnitude of the stroke; generating a current flow through the coil of the magnetic valve in order to generate a magnetic field for generating a magnetic force on the armature, which magnetic force displaces the armature in the direction for the opening of a closure element coupled to the armature; determining a magnitude of the magnetic flux when the armature abuts against a driver of the closure element; and determining the magnitude of the stroke based upon the determined magnitude of the magnetic flux and the reference data set.

In some examples, a static part includes a static body and a first cylindrical extension extending from the static body, the first cylindrical extension including an open end with a cylindrical inner surface having a first diameter. A moveable part is moveable toward the static part by the magnetic flux of a solenoid. The moveable part may include a moveable body and a second cylindrical extension extending from the moveable body, the second cylindrical extension including a cylindrical outer surface having a second diameter, smaller than the first diameter, to enable the cylindrical outer surface to move within the open end. The second diameter is sized for the cylindrical outer surface to pass adjacent to the cylindrical inner surface to enable passage of a portion of the magnetic flux radially to reduce an energy of impact between the moveable part and the static part.

The present invention controls the pressure and flow rate of fluid, in order to obtain uniform performance, configure a closed loop magnetic circuit so as to include an electromagnet, a flapper, and a yoke material, and elastically deform the flapper itself by Maxwell attractive force generated between a magnetic pole of the electromagnet and the flapper to make the separation distance between the nozzle and the flapper variable. As opposed to a rigid flapper structure that swingably moves around a supporting point, like a conventional servo valve, the electromagnet, the magnetic pole, the nozzle, the flapper, and the like are arranged such that a change in magnetic gap directly leads to a change in air gap.

A solenoid device includes a yoke, a core, a shaft, a bobbin, a coil, a plunger, a lid, and a housing. A housing body part of the housing has a first opening; a cylindrical first inner wall part having a first step part extending toward the outer side in the radial direction; and a cylindrical second inner wall part having a second step part extending toward the outer side in the radial direction. A first cylindrical part has a first flange part. The outer diameter of the first flange part is larger than the inner diameter of the first inner wall part and smaller than the inner diameter of the second inner wall part. A circumferential end part of the first flange part contacts the second step part. The lid is non-magnetic, and a circumferential edge part is held between the first step part and the first flange part.