JP7443282B2 - solenoid - Google Patents

Description

The present invention relates to a solenoid configured to move in a direction along an axis.

The solenoid includes a stator, a mover, and a coil that are shaped to revolve around an axis, the stator is made of a magnetic material, and has an end face facing the mover, and the mover includes: A magnetic body that moves along the axial direction with respect to the stator, and is formed in a hollow cylindrical portion provided around the axial center, and at an end in the axial direction of the cylindrical portion; a plate-shaped opposing portion facing the end surface of the stator, the coil concentrically orbiting the stator, and configured to move the movable element toward the stator when energized. The opposing portion of the movable element is configured in a disk shape (see Patent Document 1 (not published) filed by the applicant of the present invention).

In Patent Document 1, the magnetic flux lines of the magnetic field generated by energizing the coil move from the stator to the opposing part via the cylindrical part of the mover, and from the opposing part to the stator, thereby causing the mover to move. An attractive force is generated toward the stator, and the mover moves toward the stator. However, since the facing part of the mover is configured in a disk shape, the stator does not exist in the direction in which the magnetic flux lines that have moved to the facing part come out from the outer peripheral surface of the facing part, so the magnetic flux lines are dispersed. However, it is difficult to move toward the stator side. Therefore, the amount of magnetic flux lines directed from the movable element toward the end face of the stator decreases, resulting in a disadvantage that the force for moving the movable element toward the stator decreases.

Patent application 2020-142979

Therefore, an object of the present invention is to provide a solenoid that can suppress a reduction in the amount of magnetic flux lines moving from the mover to the stator.

The solenoid of the present invention is a solenoid configured to move in a direction along an axis, and includes a stator, a movable element, and a coil shaped to revolve around the axis, and the stator is made of a magnetic material. and has an end face facing the movable element in the axial direction, the movable element is a magnetic body that moves along the axial direction with respect to the stator, and is provided around the axial center. , comprising: a hollow cylindrical portion that abuts against the stator; and a plate-shaped opposing portion formed at an axial end of the cylindrical portion and facing the end surface of the stator; The coil concentrically revolves around the stator, is configured to move the mover toward the stator when energized, and extends toward the stator at an outer peripheral edge of the opposing portion. The coil is also characterized in that it includes an extending portion having a tip that is spaced apart from the end surface of the stator when the coil is not energized.

According to the present invention, since the outer peripheral edge of the facing portion is provided with an extending portion that extends toward the stator and has a tip spaced apart from the movable element, the magnetic flux lines of the magnetic field generated when the coil is energized are provided. However, it moves from the stator to the opposing part via the cylindrical part, and tends to head toward the stator from the tip of the extending part facing toward the stator. Thereby, it is possible to suppress the amount of magnetic flux lines moving from the mover to the stator from decreasing.

Further, in the solenoid of the present invention, the extending portion is provided over the entire circumference of the outer peripheral edge of the opposing portion, and when the coil is energized and the mover is moved to the stator, The extending portion may be configured to overlap an outer circumferential surface of the stator.

According to the above configuration, when the coil is energized and the mover is moved toward the stator, if the extending portion is configured to overlap the outer peripheral surface of the stator, the axial direction of the solenoid Dimensions can be shortened.

Further, the solenoid of the present invention is a solenoid configured to move in a direction along an axial center, and includes a stator, a movable element, and a coil shaped to revolve around the axial center, and the stator is configured to move in a direction along the axial center. A magnetic path forming part for forming a magnetic path of magnetic flux lines circulating around the coil in a core cross section, a housing part for accommodating a shaft made of a magnetic material, and the shaft is inserted into the magnetic path forming part. A shaft accommodating part made of a non-magnetic material, the shaft accommodating part having a notch or a through hole for exposing an outer surface of the shaft to the magnetic path forming part, may include a convex portion that protrudes radially inward through a notch or through hole of the shaft accommodating portion and comes into contact with the shaft.

According to the above configuration, the coil is energized and the magnetic path forming section forms a magnetic path for magnetic flux lines that go around the coil. The magnetic flux lines move from the convex part of the magnetic path forming part to the shaft, and the magnetic flux lines that have moved to the shaft merge with the magnetic flux lines circulating around the coil, thereby suppressing the amount of magnetic flux lines from decreasing. .

According to the present invention, the outer peripheral edge of the facing portion is provided with an extending portion that extends toward the stator and has a tip spaced apart from the movable element, or the magnetic path forming portion provided in the stator is provided in the notch of the shaft accommodating portion. By providing a convex portion that protrudes radially inward through the portion or through hole and contacts the shaft, it is possible to provide a solenoid that can suppress a reduction in the amount of magnetic flux lines moving from the mover to the stator.

FIG. 2 is a front view of the solenoid of the present invention. It is a side view of the same solenoid. It is a perspective view of the solenoid seen from the back side. It is an exploded perspective view of the same solenoid. Components constituting the solenoid are shown, in which (a) is a perspective view of a shaft accommodating portion, and (b) is a perspective view of a field. 2 is a sectional view taken along the line VI-VI in FIG. 1, showing the flow of magnetic flux lines. FIG. 7 is a sectional view showing a state in which the movable element of the solenoid in FIG. 6 is attracted to the stator.

One embodiment of the present invention will be described below with reference to the drawings.

A solenoid 1 according to an embodiment of the present invention is configured to not rotate but to move only in a direction along its axis, and is shown in FIGS. 1 to 4. This solenoid 1 includes a stator 2, a coil 3 (see FIG. 6), and a movable element 4, which are shaped to revolve around the axis, as well as a spring 5, a bobbin 6, a field 7, and a terminal block 8A attached to the bobbin 6. The shaft accommodating portion 12 (see FIG. 5(a)) has a accommodating portion 12A for accommodating a cylindrical shaft 11 made of a magnetic material. This solenoid 1 is applied to, for example, a paper feed mechanism of a copying machine. The shaft 11 does not belong to the solenoid 1, but belongs to a part of the paper feed mechanism, etc., to which the solenoid 1 is attached. The bobbin 6, the terminal cover 8, and the shaft accommodating portion 12 are made of synthetic resin, which is a non-magnetic material. The spring 5 is arranged so as to move the movable element 4 in the direction of separating it from the stator 2 when not energized. Specifically, as shown in FIG. 6, it is disposed between the lower end of the second inner part 73 of the field 7, which will be described later, and the upper end of the cylindrical part 41 of the movable element 4, which will be described later. Here, the stator 2 is provided with a magnetic path forming part for forming a magnetic path of the magnetic flux lines circulating around the coil 3 in the axial cross section, and this magnetic path forming part is formed from the field 7 that contacts the stator 2. It is configured. The terminal block 8A and the terminal cover 8 can be made of synthetic resin, metal, or the like.

The stator 2 is composed of a metal plate made of a magnetic material (for example, a plated steel plate, etc.), has an end surface 2T facing the movable element 4, and has a circular ring shape as shown in FIGS. 4 and 6. a plate-shaped end surface portion 21; a first outer cylindrical portion 22 extending from the outer peripheral edge of the end surface portion 21 toward the side away from the mover 4; and a first outer cylinder portion 22 extending from the inner peripheral edge of the end surface portion 21 toward the side away from the mover 4. An inner cylinder part 23 is provided. The end face portion 21 is provided with a stator window portion 9 divided in the radial direction. In the following description, the mover side in the axial direction of the solenoid 1 will be referred to as the lower side, the field side of the solenoid 1 will be referred to as the upper side, and the direction perpendicular to the axial direction will be referred to as the left and right direction.

As shown in FIG. 6, the first outer cylindrical portion 22 has a cylindrical shape extending along the axial direction (upward in the figure), and is shorter than the first inner cylindrical portion 23 in the axial direction. ing. Like the first outer cylinder part 22, the first inner cylinder part 23 has a cylindrical shape extending along the axial direction (upward in the figure), and has a longer dimension in the axial direction than the first outer cylinder part 22. It is composed of Note that the first inner cylinder part 23 may be configured to have a shorter dimension in the axial direction than the first outer cylinder part 22, or the first inner cylinder part 23 may be shorter than the first outer cylinder part 22 in the axial direction. 22 may be configured to have the same length.

The movable element 4 is configured to be movable along the axial direction with respect to the stator 2. The mover 4 is composed of a metal plate made of a magnetic material (for example, a plated steel plate, etc.), and as shown in FIGS. A ring-shaped and plate-shaped opposing part 42 having a circular outer shape and a plate-like shape is integrally formed at the axial end (upper end in the axial direction) and faces the end surface 2T of the stator 2; A cylindrical extending portion 43 is integrally formed so as to extend toward the stator 2 (toward the stator 2 side) on the outer peripheral edge of the stator. The tip 43T of the extending portion 43 is spaced apart from the lower end of the stator 2 with a gap. This gap is set to a size that allows the lines of magnetic flux to easily move from the extension portion 43 to the stator 2. The opposing part 42 is provided at a different position in the radial direction and circumferential direction from the stator window part 9 of the stator 2, and has a movable element window part 10 divided in the radial direction. In this embodiment, the mover 4 is constructed by press-molding a metal plate (for example, a plated steel plate, etc.).

The inner diameter of the extending portion 43 is set larger than the outer diameter of the stator 2, so that when the coil 3 is energized and the mover 4 is moved toward the stator 2, the extending portion 43 is fixed. It is configured to overlap the outer circumferential surface of the end of the first outer cylindrical portion 22 of the child 2 on the movable element 4 side (see FIG. 7). In this way, when the coil 3 is energized and the movable element 4 is moved to the stator 2, the extending part 43 is configured to overlap the outer peripheral surface of the first outer cylinder part 22 of the stator 2. If so, the dimension of the solenoid 1 in the axial direction can be shortened. As in this embodiment, it is preferable that the extending portion 43 is configured to extend substantially parallel to the axial direction, but the extending portion 43 has a shape that expands outward toward the tip side (upper end side). Alternatively, in some cases, the extending portion 43 may be configured to have a tapered shape such that the tip (upper end) side of the extending portion 43 is located inward.

The coil 3 is wound around a synthetic resin bobbin 6 whose radially outer side is open so as to rotate concentrically with respect to the stator 2 . The coil 3 is energized by being energized and attracts the movable element 4 to the stator 2 against the biasing force of the spring 5. The upper side of the bobbin 6 around which the coil 3 is wound is covered with a field (also referred to as a casing) 7.

As shown in FIGS. 4 and 6, the bobbin 6 includes a cylindrical portion 61 for winding the coil 3, a ring-shaped lower plate portion 62 extending outward in the left-right direction from the lower end of the cylindrical portion 61, and an upper end of the cylindrical portion 61. A ring-shaped upper plate portion 63 extends outward in the left-right direction from the top. A plurality of (three in FIG. 4) cylindrical projections 62A projecting downward are formed on the lower end surface of the lower plate portion 62 at intervals in the circumferential direction. These protrusions 62A are locked in three through holes 21A of a plurality (six in FIG. 4) of circular through holes 21A formed at intervals in the circumferential direction in the end surface 21 of the stator 2. ing. In the locked state, the lower end portion of the protrusion 62A protrudes downward from the lower end surface of the end surface portion 21 of the stator 2, and when the movable element 4 is attracted to the stator 2, the lower end portion of the protrusion 62A The upper end surface 42A (see FIG. 7) of the facing portion 42 abuts the tip end surface of the protrusion 62A, thereby regulating the suction position of the movable element 4. Note that three protrusions 125, which will be described later, are engaged from the opposite direction (from below) in each of the remaining three through holes 21A that are not engaged by the protrusion 62A. Further, as shown in FIGS. 2, 3, and 7, a prismatic protrusion 13 that protrudes upward is provided on the upper end surface of the upper plate portion 63. This protruding portion 13 is inserted into a rectangular through hole 71A formed in a plate portion 71 of the field 7, which will be described later, and protrudes to the outside. The protrusion 13 is provided as a member that is fixed to a fixed member inside the copying machine to prevent the stator 2 from rotating inside the copying machine.

The shaft accommodating portion 12 is made of synthetic resin, which is a non-magnetic material, and as shown in FIG. A cylindrical portion 122 extending upward from the cylindrical portion 122 is provided. The shaft 11 is fitted into the shaft accommodating portion 12 . The shaft 11 is provided within the copying machine. Further, at the upper end of the cylindrical portion 122, a plurality of (three in FIG. 4) leg portions 123, 123, 123 extending upward are provided at intervals in the circumferential direction. A notch (or a through hole may be formed in the cylindrical body) for exposing the outer surface of the shaft 11 between the leg parts 123, 123 adjacent in the circumferential direction of these leg parts 123, 123, 123 123K is formed. The lower end surface 21B of the end surface section 21 of the stator 2 is inserted into three through holes 42K formed in the facing section 42 of the mover 4 at three locations in the circumferential direction of the outer periphery of the upper end surface of the plate section 121. A contact portion 124 is formed to contact the stator 2 and restrict the position of the stator 2 on the lower side in the axial direction. Further, each contact portion 124 is formed with a cylindrical projection 125 that projects downward. These protrusions 125 engage the remaining three through holes 21A from below. Further, the upper end of each leg portion 123 is provided with a claw portion 126 for engaging the inner peripheral edge of the plate portion 71 of the field 7 from above in the axial direction to regulate the upper position of the field 7 in the axial direction. ing. Therefore, by setting the shaft accommodating part 12, the three contact parts 124 come into contact with the lower end surface 21B of the end face part 21 of the stator 2, and the three claw parts 126 are brought into contact with the inner part of the plate part 71 of the field 7. Attach to the periphery. Thereby, all the members constituting the solenoid 1 can be fixed in an integrated state.

Further, by providing the three contact portions 124, the movable element 4 is prevented from rotating and being tilted with respect to the axial direction, and is smoothly and reliably guided along the axial direction. More specifically, as shown in FIG. 6, the arcuate inner surfaces 124A of the three contact portions 124 (only one is shown in FIG. 6) and the outer circumferential surface 122A of the cylindrical portion 122 cause the movable member 4 to An arcuate outer circumferential surface of the four surfaces that guide and support the cylindrical portion 41 and form the three through holes 42K of the opposing portion 42 of the mover 4 with the arcuate outer surface 124B of the three contact portions 124. By guiding and supporting 42G, it is possible to reliably prevent tilting, especially in the axial direction.

The field 7 is composed of a metal plate made of a magnetic material (for example, a plated steel plate, etc.), and as shown in FIGS. 4 and 7, the field 7 faces the upper plate part 63 of the bobbin 6 in the axial direction and covers the upper plate part 63. a plate-like ring-shaped plate part 71; an arc-shaped second outer part 72 for covering the outer peripheral part of the bobbin 6 excluding the part of the outer peripheral edge of the plate part 71 where the terminal block 8A is located; A cylindrical second inner part 73 extending from the inner peripheral edge of the plate part 71 toward the bobbin is provided. The lower side of the second outer part 72 is located inside the upper side of the first outer cylindrical part 22 of the stator 2, overlaps with it in the radial direction, and is in contact with it. Further, the lower part of the second inner part 73 is located outside the upper part of the first inner cylindrical part 23 of the stator 2, overlaps in the radial direction, and is in contact with the second inner part 73.

The plate portion 71 is formed with a rectangular through hole 71A through which the protrusion 13 can be inserted. As shown in FIG. 4, the second inner portion 73 includes three recesses 73A into which the three leg portions 123 fit, and a convex portion that protrudes radially inward into the three notches 123K and contacts the outer surface of the shaft 11. 73B. Therefore, the magnetic flux lines move from the convex portion 73B of the field 7 to the shaft 11. That is, as shown in FIG. 6, a magnetic field is generated by energizing the coil 3, and magnetic flux lines are distributed between the first outer cylindrical portion 22 of the stator 2, the second outer portion 72 of the field 7, and the plate portion 71 of the field 7. , passes through the second inner part 73 of the field 7, moves to the first inner cylinder part 23 of the stator 2, and moves from the convex part 73B of the second inner part 73 to the shaft 11. Both the magnetic flux lines that have moved to the first inner cylindrical portion 23 of the stator 2 and the magnetic flux lines that have moved to the shaft 11 merge into the cylindrical portion 41 of the mover 4, thereby further suppressing the amount of magnetic flux lines from decreasing. can do. Further, the magnetic flux lines easily move from the cylindrical part 41 of the movable element 4 to the opposing part 42, and from the tip of the extending part 43 of the opposing part 42 toward the stator side. Thereby, it is possible to suppress a decrease in the amount of magnetic flux lines moving from the facing portion 42 toward the stator side, and it is possible to suppress a decrease in the amount of circulating magnetic flux lines. Note that the magnetic flux lines that have moved to the first inner cylindrical portion 23 of the stator 2 also move to the end surface portion 21 in addition to the cylindrical portion 41 of the mover 4, and from the end surface portion 21 to the first outer cylindrical portion of the stator 2. Move to 22. At this time, the magnetic flux lines from the tip 43T of the extending portion 43 also move to the first outer cylindrical portion 22 of the stator 2.

As shown in FIG. 4, the movable element window 10 provided in the movable element 4 includes a plurality of (four in this embodiment) circular arc-shaped windows formed at one location in the radial direction at intervals along the circumferential direction. It is composed of two types of slits 10A and 10B, long and short. The two longer slits 10A each have the same circumferential length and the same radial width. Further, each of the two shorter slits 10B has the same circumferential length and the same radial width. A rectangular engagement portion that can be engaged with an operation object 14, which will be described later, is provided between the two longer slits 10A and 10A and between the two shorter slits 10B and 10B, respectively. A protrusion 10T having a substantially square shape is formed. In this embodiment, when the coil 3 is de-energized, the movable element 4 moves away from the stator 2, so that the protrusion 10T engages with the operation object 14 (see FIG. 1).

As shown in FIG. 4, the stator window portion 9 provided in the stator 2 includes a plurality of (in this embodiment, three) arc-shaped windows formed at two locations in the radial direction at intervals along the circumferential direction. It is composed of slits 9A, 9A, 9A, 9B, 9B, and 9B. The three radially outer arcuate slits 9A, 9A, 9A all have the same width in the radial direction and the same length in the circumferential direction. Furthermore, the three radially inner arcuate slits 9B, 9B, and 9B all have the same width in the radial direction and the same length in the circumferential direction; The length in the circumferential direction is also shorter. Note that the radial width of the slits 9A and 9B is set larger than the radial width of the slits 10A and 10B provided in the movable element 4. There are three connecting portions 9C between the outer slits 9A, 9A that are adjacent to each other in the circumferential direction at 120 degree intervals in the circumferential direction, and the lengths of the three connecting portions 9C in the circumferential direction are all the same. There are three connecting portions 9D between the inner slits 9B, 9B that are adjacent to each other in the circumferential direction at 120 degree intervals in the circumferential direction, and the lengths of the three connecting portions 9D in the circumferential direction are all the same. The outer connecting portion 9C and the inner connecting portion 9D are located at different positions in the radial direction.

The four slits 10A and 10B of the movable element 4 are located between the three slits 9A on the radially outer side of the stator 2 and the three slits 9B on the radially inner side. Further, the radial width of the slits 10A, 10B provided in the movable element 4 is made smaller than the radial width of the slits 9A, 9B provided in the stator 2. Thereby, the distance between the slits 9A and 9B adjacent to each other in the radial direction of the stator 2 can be kept small.

As described above, by providing the slits 10A and 10B of the movable element 4 between the slits 9A and 9A of the stator 2, the coil 3 of the solenoid 1 is energized, and the movable element 4 moves to the stator 2 and is strengthened. It is adsorbed. In other words, the magnetic flux lines flowing from the field 7 to the stator 2 flow from the outer periphery of the end surface 21 of the stator 2 to the inner periphery from the mover 4 → stator 2 → mover 4 → stator 2. After that, it flows towards field 7. By repeatedly moving the magnetic flux lines between the movable element 4 and the stator 2 in this manner, the amount of attraction can be increased. Therefore, by forming the stator window portion 9 and the mover window portion 10 as described above, the magnetic efficiency does not decrease. Moreover, unlike an electromagnetic clutch, there is no rotation, so the position of the movable window section 10 relative to the stator window section 9 does not change, so that an attractive force of a predetermined magnitude can always be stably generated.

The operation of solenoid 1 will be explained. When the movable element 4 is not in operation, it is located at a position separated (projected) from the stator 2 due to the biasing force of the spring 5 (see FIG. 6), and is operated by one protrusion 10T, which is the engagement part of the stator 2. The object 14 is engaged and the operation object 14 remains stopped at that position (see FIG. 1). The operation object 14 is attached to a rotating body (not shown) that is rotatably provided on the same axis as the solenoid 1 . When the mover 4 is in operation, the coil 3 is energized so that the mover 4 is attracted to the stator 2 against the biasing force of the spring 5 (retracted position, see FIG. 7). As a result, the engagement with the operation object 14 is released, the operation object 14 rotates, and the current supply to the coil 3 is cut off before the operation object 14 passes the other protrusion 10T and rotates once. As a result, the movable element 4 returns to the protruding position (initial position) by the urging force of the spring 5. As a result, the rotating operation object 14 engages with the protrusion 10T, which is the engagement section of the stator 2, and is stopped at a position where it has made one rotation.

As described above, the present invention is not limited to the embodiments described above, and various changes can be made without departing from the gist of the present invention. For example, the solenoid may be constructed by replacing the flat plate-shaped movable element of the solenoid disclosed in Japanese Patent Application No. 2020-142979 filed by the applicant of the present invention with the movable element 4 having the extending portion 43 of the present invention.

In the embodiment described above, the shaft accommodating portion 12 was provided with three legs 123, but it may be configured with any number of legs such as one, two, four or more.

Further, in the embodiment, the movable element 4 is formed by press-forming a metal plate, but the movable element 4 may be formed by drawing, roll forming, bending, casting, forging, or the like.

Furthermore, in the embodiment described above, the movable member 4 is provided with two engaging portions 10T that can be engaged with the operation target object 14, but the engaging portions 10T may be provided at one location or at three or more locations. Further, the shape of the engaging portion 10T is not limited to a rectangular shape, and may be any shape such as a triangular shape, a polygonal shape of pentagon or more, an oval shape, etc. Furthermore, the engaging portion 10T may be a recess instead of a protrusion. In addition, the engaging portion 10T and the operation target object 14 are not limited to approaching and separating, but may be constantly connected by a link or the like.

Further, in the above embodiment, each of the stator 2 and the movable element 4 is configured to have a shape that spans the entire circumference (360 degrees). Good too. In addition, in the embodiment, a case that revolves in a circumferential manner is shown, but it may also revolve in a polygonal shape.

Further, in the above embodiment, the outer shape of the movable element 4 is circular, but it may have any shape such as an ellipse or a polygon. For example, the slits 10A and 10B may have the same shape as the embodiment, but the cylindrical portion 41 and the opposing portion 42 may have a different shape from the embodiment.

Further, in the above embodiment, the stator 2 has a circular outer shape, but it may have any shape such as an ellipse or a polygon. In this case, the slits 9A and 9B may have the same shape as in the embodiment, and only the outer shape of the stator 2 may have a different shape.

Further, in the above embodiment, the outer shape of the mover 4 is circular, and the outer shape of the stator 2 is also circular. It may also be configured in a polygonal shape.

1...Solenoid, 2...Stator, 2T...End face, 3...Coil, 4...Mover, 6...Bobbin, 7...Field, 8...Terminal cover, 8A...Terminal block, 9...Stator window, 9A, 9B ...Slit, 9C, 9D...Connection part, 10...Mover window part, 10A, 10B...Slit, 10T...Protrusion part, 10T...Engagement part, 11...Shaft, 12...Shaft accommodation part, 12A...Accommodation part, 12K ...Opening, 13...Protrusion, 14...Operation target, 21...End face part, 21A...Through hole, 21B...Lower end face, 41...Cylinder part, 42...Opposing part, 42A...Upper end face, 42G...Outer peripheral surface, 42K ...Through hole, 43...Extension part, 43T...Tip, 61...Cylindrical part, 62...Lower side plate part, 62A...Protrusion, 63...Upper side plate part, 71...Plate part, 71A...Through hole, 72...Second outer side part, 73...second inner part, 73A...recessed part, 73B...convex part, 121...plate part, 122...cylindrical part, 122A...outer peripheral surface, 123...leg part, 123K...notch part, 124...contact part, 124A...Inner surface, 124B...Outer surface, 125...Protrusion, 126...Claw portion

Claims (2)

In a solenoid configured to move in the direction along the axis,
A stator, a mover, and a coil each having a shape that revolves around the axis,
The stator is made of a magnetic material and has an end face facing the movable member in the axial direction,
The movable element is a magnetic body that moves along the axial direction with respect to the stator, and includes a hollow cylindrical part provided around the axial center and in contact with the stator, and the cylindrical part. a plate-shaped opposing portion formed at an axial end portion of the stator and facing the end surface of the stator;
The coil is configured to revolve concentrically with respect to the stator, and is configured to move the movable element toward the stator when energized,
an extending portion extending toward the stator and having a tip spaced apart from the end surface of the stator when the coil is not energized ;
Furthermore,
The stator includes a magnetic path forming part for forming a magnetic path of magnetic flux lines that circulate around the coil in an axial cross section,
a shaft accommodating part that accommodates a shaft made of a magnetic material, and a shaft accommodating part made of a non-magnetic material that is inserted into the magnetic path forming part;
The shaft accommodating part includes a notch or a through hole for exposing the outer surface of the shaft to the magnetic path forming part,
The solenoid is characterized in that the magnetic path forming portion includes a convex portion that protrudes radially inward through a notch or through hole of the shaft accommodating portion and comes into contact with the shaft . The extending portion is provided over the entire circumference of the outer peripheral edge of the opposing portion, and when the coil is energized and the movable element is moved to the stator, the extending portion extends around the outer periphery of the stator. The solenoid according to claim 1, wherein the solenoid is configured to overlap an outer peripheral surface.