Systems and methods for a solenoid supervisory detection system which can detect the presence or absence of a solenoid plunger within a solenoid coil. These systems can be used to verify correct reassembly of a solenoid valve after it has been disassembled for testing.

In one aspect, there is disclosed a solenoid having a bobbin with a core wire positioned about the bobbin to form a coil. A power supply wire is connected an end of the core wire and a frame is connected to the bobbin. An overmolded housing surrounds the core wire, the frame and a portion of the power supply wire.

A solenoid includes a coil portion and a yoke having a side surface portion along an axial direction so as to accommodate the coil portion. A gap in a radial direction that communicates a radial outside of a first magnetic flux transfer portion with an outside of the solenoid is formed between an inner surface of the side surface portion and an outer surface of the coil portion, and a protrusion is formed on at least one of an inner surface and an outer surface and protrudes in the radial direction to reduce a size of at least a part of the gap.

A solenoid includes a coil portion and a yoke having a side surface portion along an axial direction so as to accommodate the coil portion. A gap in a radial direction that communicates a radial outside of a first magnetic flux transfer portion with an outside of the solenoid is formed between an inner surface of the side surface portion and an outer surface of the coil portion, and a protrusion is formed on at least one of an inner surface and an outer surface and protrudes in the radial direction to reduce a size of at least a part of the gap.

A magnetizing device includes a magnetic field generator configured to generate a parallel magnetic field in a preset region. The parallel magnetic field magnetizes the element which is located in the preset region.

A magnetizing device includes a magnetic field generator configured to generate a parallel magnetic field in a preset region. The parallel magnetic field magnetizes the element which is located in the preset region.

In the actuator, the first end plate part of the first cover member in the support body is layered on one side in the first direction of the holder and faces the first yoke of the movable body from one side in the first direction. The second end plate part of the second cover member in the support body is layered on the other side in the first direction of the holder and faces the movable body from the other side in the first direction. Thus, the first viscoelastic member interposed between the movable body and the first end plate part in the first direction properly contacts with the movable body and the first end plate part. The second viscoelastic member interposed between the movable body and the second end plate part in the first direction properly contacts with the movable body and the second end plate part.

In the actuator, the first end plate part of the first cover member in the support body is layered on one side in the first direction of the holder and faces the first yoke of the movable body from one side in the first direction. The second end plate part of the second cover member in the support body is layered on the other side in the first direction of the holder and faces the movable body from the other side in the first direction. Thus, the first viscoelastic member interposed between the movable body and the first end plate part in the first direction properly contacts with the movable body and the first end plate part. The second viscoelastic member interposed between the movable body and the second end plate part in the first direction properly contacts with the movable body and the second end plate part.

An electromagnetic actuator includes a stator and a movable element. The movable element is attracted from a stroke start position to a stroke end position in a predetermined stroke in an axial direction by magnetic force generated between the stator and the movable element when a coil is energized. The stator includes a first stator located adjacent to the movable element at the stroke start position and a second stator located closer to the movable element at the stroke end position than at the stroke start position. The movable element includes a tapered portion that has a diameter becoming smaller toward the second stator and a protrusion that protrudes from an end surface of the movable element close to the second stator.

An electromagnetic actuator includes a stator and a movable element. The movable element is attracted from a stroke start position to a stroke end position in a predetermined stroke in an axial direction by magnetic force generated between the stator and the movable element when a coil is energized. The stator includes a first stator located adjacent to the movable element at the stroke start position and a second stator located closer to the movable element at the stroke end position than at the stroke start position. The movable element includes a tapered portion that has a diameter becoming smaller toward the second stator and a protrusion that protrudes from an end surface of the movable element close to the second stator.