JP2024002252A - electromagnetic actuator - Google Patents

Abstract

[Problem] To suppress fluctuations in magnetic driving force during displacement by devising the shape of the plunger and stator core without using permanent magnets.
[Solution] The stator core includes a stator facing surface that faces the plunger through a magnetic gap, a stator cylindrical part located on the first direction side of the stator facing surface, and a second direction from the outer periphery of the stator cylindrical part. and a stator cylindrical portion extending into the stator. The plunger includes a plunger facing surface that faces the stator core through a magnetic gap, and a plunger cylindrical part that is located on the second direction side of the plunger facing surface and can face the inner periphery of the stator cylindrical part. Since the stator cylindrical portion extends in the second direction, the distance between the stator facing surface and the plunger facing surface can be increased, and the stroke of the plunger can be increased. When the coil is excited, magnetic flux is passed through the cylindrical part of the stator, thereby adjusting the magnetic attraction between the stator facing surface and the plunger facing surface.
[Selection diagram] Figure 2

Description

The present disclosure relates to an electromagnetic actuator, and can be used, for example, to drive a clutch mechanism or to a sealing valve that opens and closes a flow path of working fluid.

Patent Document 1 discloses an electromagnetic actuator whose electromagnetic driving force has a substantially constant value with little fluctuation when reciprocating between an initial position and an actuation position. However, in Patent Document 1, two permanent magnets facing a plunger shaft made of a non-magnetic material are used to suppress fluctuations in the magnetic driving force. Therefore, the structure of Patent Document 1 requires permanent magnets and the like, and an increase in the number of parts leads to an increase in product cost.

Japanese Patent Application Publication No. 2011-82319

In view of the above points, an object of the present disclosure is to suppress fluctuations in magnetic attraction force when the plunger is displaced by devising the shapes of the plunger and the stator core without using permanent magnets.

A first aspect of the present disclosure provides a coil that is excited when energized, a stator core made of a magnetic material that is placed in a magnetic circuit when the coil is energized, and a stator core and a magnetic gap that are placed in the magnetic circuit when the coil is energized. This electromagnetic actuator has a plunger made of a magnetic material that is arranged facing each other and moves in a first direction toward the stator core by magnetic attraction when the coil is energized, and moves in a second direction away from the stator core when the coil is not energized.

The stator core of the first electromagnetic actuator of the present disclosure includes a stator facing surface that faces the plunger through a magnetic gap, a stator cylindrical part located on the first direction side of the stator facing surface, and a stator cylindrical part located on the first direction side of the stator facing surface. and a stator cylindrical portion extending in the second direction from the outer periphery. The plunger includes a plunger facing surface that faces the stator core through a magnetic gap, and a plunger cylindrical part that is located on the second direction side of the plunger facing surface and can face the inner periphery of the stator cylindrical part. ing.

In the first electromagnetic actuator of the present disclosure, when the coil is not energized, there is a first A magnetic gap is formed in the direction and the second direction. Furthermore, when the coil is energized, the outer periphery of the plunger cylindrical part faces the inner periphery of the stator cylindrical part, and the space between the inner periphery of the stator cylindrical part and the outer periphery of the plunger cylindrical part, and between the stator facing surface and the plunger facing surface. A magnetic circuit is formed between the two.

In the first electromagnetic actuator of the present disclosure, since the stator cylindrical portion is formed to extend in the second direction, the distance between the stator facing surface and the plunger facing surface can be increased, and the stroke of the plunger can be increased. You can make it bigger. When the coil is excited, magnetic flux is passed through the cylindrical part of the stator, thereby making it possible to adjust the magnetic attraction between the stator facing surface and the plunger facing surface.

A second aspect of the present disclosure is a coil that is excited when energized, a stator core made of a magnetic material that is placed in a magnetic circuit when the coil is energized, and a stator core and a magnetic gap that are placed in the magnetic circuit when the coil is energized. The electromagnetic actuator has a plunger made of a magnetic material that is arranged facing each other and moves in a first direction toward the stator core by magnetic attraction when the coil is energized, and moves in a second direction away from the stator core when the coil is not energized.

The plunger of the second electromagnetic actuator of the present disclosure includes a plunger facing surface facing the stator core through a magnetic gap, a plunger cylindrical portion located on the second direction side of the plunger facing surface, and a plunger cylindrical portion located on the second direction side of the plunger facing surface. The plunger includes a cylindrical portion extending in the first direction from the outer periphery. The stator core includes a stator facing surface that faces the plunger through a magnetic gap, and a stator cylindrical part that is located on the first direction side of the stator facing surface and can face the inner periphery of the plunger cylindrical part. ing.

In the second electromagnetic actuator of the present disclosure, when the coil is not energized, there is a first A magnetic gap is formed in the direction and the second direction. Furthermore, when the coil is energized, the outer periphery of the stator cylindrical part faces the inner periphery of the plunger cylindrical part, and there are gaps between the inner periphery of the plunger cylindrical part and the outer periphery of the stator cylindrical part, and between the stator facing surface and the plunger facing surface. A magnetic circuit is formed between the two.

In the second electromagnetic actuator of the present disclosure, since the plunger cylindrical portion is formed to extend in the first direction, the distance between the stator facing surface and the plunger facing surface can be increased, and the stroke of the plunger can be increased. You can make it bigger. When the coil is excited, magnetic flux is passed through the cylindrical portion of the plunger, thereby making it possible to adjust the magnetic attraction between the stator facing surface and the plunger facing surface.

In the third electromagnetic actuator of the present disclosure, the plunger opposing surface has a plunger concave shape whose diameter decreases from the end surface in the first direction toward the second direction, and the stator opposing surface extends from the end surface in the first direction to the second direction. The stator has a convex shape whose diameter decreases toward the end. By opposing the stator convex shape and the plunger concave shape, an appropriate magnetic attraction force can be generated between the stator facing surface and the plunger facing surface.

In the fourth electromagnetic actuator of the present disclosure, the plunger facing surface has a plunger convex shape whose diameter increases from the end face in the first direction toward the second direction, and the stator facing surface extends from the end face in the first direction to the second direction. The stator has a concave shape, with the diameter increasing towards the end. Since the stator concave shape and the plunger convex shape face each other, an appropriate magnetic attraction force can be generated between the stator facing surface and the plunger facing surface.

In the fifth electromagnetic actuator of the present disclosure, a plunger flat portion is formed around the central axis of the plunger facing surface, and a stator flat portion corresponding to the plunger flat portion is formed around the central axis of the stator facing surface. Since the stator plane part and the plunger plane part face each other, an appropriate magnetic attraction force can be generated between the stator facing surface and the plunger facing surface.

In the sixth electromagnetic actuator of the present disclosure, a washer made of a non-magnetic material is disposed on either the stator facing surface or the plunger facing surface. By arranging the washer made of non-magnetic material, it is possible to prevent the plunger from becoming difficult to separate from the stator core due to residual magnetism.

FIG. 3 is a cross-sectional view of the electromagnetic actuator when it is not energized. FIG. 3 is a sectional view of the electromagnetic actuator when it is energized. It is a figure which shows operation|movement of an electromagnetic actuator at the time of non-energization. It is a figure which shows operation|movement when the electromagnetic actuator is energized. It is a figure explaining the magnetic flux of an electromagnetic actuator. It is a figure which shows the attraction force of the electromagnetic actuator shown in FIG.1 and FIG.2, and a comparative example. FIG. 3 is a cross-sectional view showing a comparative example. It is a sectional view showing other examples of a stator core and a plunger. It is a sectional view showing still another example of a stator core and a plunger. FIGS. 7 to 9 are diagrams showing the attraction force of the electromagnetic actuator shown in FIGS. It is a sectional view explaining other examples of an electromagnetic actuator. It is a sectional view explaining still another example of an electromagnetic actuator. It is a sectional view explaining still another example of an electromagnetic actuator.

An example in which the electromagnetic actuator 100 of the present disclosure is used in a clutch mechanism will be described. As shown in FIGS. 1 and 2, the electromagnetic actuator 100 includes a coil bobbin 101 made of resin and a coil 102 made of enamel-coated copper wire wound around a coil bobbin 101 many times. The coil bobbin 101 is made of, for example, polyphenylene sulfide (PPS) and has a cylindrical shape. A stator core 110 and a plunger 130 are arranged on the inner periphery of the coil bobbin 101. The stator core 110 is made of a magnetic material, such as SUS430 or iron material. The plunger 130 is also made of magnetic material, and similarly SUS430 or iron material is used.

Further, the outer periphery of the coil bobbin 101 is covered with an outer shell 120 made of resin. The shell 120 is also made of polyphenylene sulfide (PPS). A connector (not shown) that holds a positive terminal and a negative terminal electrically connected to the coil is formed integrally with this outer shell 120. A cylindrical yoke 150 is arranged around the outer periphery of the coil 102 via the outer shell 120. In this example, the yoke 150 is integrally formed with the stator core 110, but it is also possible to arrange the cylindrical yoke 150 around the outer periphery of the stator core 110. In that case, the yoke 150 is also made of SUS430 or iron material as the magnetic material. A plate 151 is arranged in the opening of the yoke 150. This plate 151 is also made of magnetic material, and similarly SUS430 or iron material is used. Therefore, the coil 102 is surrounded by a stator core 110, a plunger 130, a yoke 150, and a plate 151 made of magnetic material. Therefore, when the coil 102 is excited, a magnetic circuit is formed by the stator core 110, the plunger 130, the yoke 150, and the plate 151.

The direction in which the plunger 130 moves toward the stator core 110 is defined as a first direction (downward in FIG. 1), and the direction in which the plunger 130 moves away from the stator core 110 is defined as a second direction (upward in FIG. 1). The stator core 110 has a stator cylindrical portion 111 formed on the first direction side. A stator facing surface 112 facing the plunger 130 is formed in the second direction of the stator cylindrical portion 111. The stator facing surface 112 has a tapered convex shape whose diameter decreases as it goes from the stator cylindrical portion 111 toward the second direction. Hereinafter, in this example, the shape of the stator facing surface 112 shown in FIG. 1 will be referred to as a stator convex shape. In this example, a stator flat portion 1121 is formed around the central axis of the stator convex shape.

Further, a ring-shaped stator cylindrical portion 113 is formed integrally extending from the outer periphery of the stator cylindrical portion 111 of the stator core 110 to the outer periphery of the stator opposing surface 112. The protruding distance of the second direction end portion 1131 of the stator cylindrical portion 113 from the stator cylindrical portion 111 is set to be somewhat shorter than the magnetic gap A between the stator core 110 and the plunger 130. For example, when the magnetic gap A is about 10 mm, the protrusion amount of the stator cylindrical portion 113 is about 8 mm. The second direction end portion 1131 of the stator cylindrical portion 113 has an edge shape that slopes toward the plunger 130 as it goes in the second direction (as shown in FIG. 5).

The plunger 130 has a cylindrical shape, and the outer diameter of the plunger cylindrical portion 131 is slightly smaller (about 0.5 to 1 mm) than the inner diameter of the stator cylindrical portion 113. Therefore, the plunger cylindrical portion 131 can fit into the inner periphery of the stator cylindrical portion 113. The first direction of the plunger cylindrical portion 131 is a plunger facing surface 132 that faces the stator core 110. This plunger facing surface 132 has a shape corresponding to the stator facing surface 112. That is, it has a tapered concave shape whose diameter decreases from the end face in the first direction toward the second direction. Hereinafter, in this example, the shape of the plunger facing surface 132 shown in FIG. 1 will be referred to as a plunger concave shape.

In this example, the area around the central axis of the plunger concave shape is flat, and a plunger flat portion 1321 is formed. As described above, the stator flat portion 1121 having a shape corresponding to the plunger flat portion 1321 is also formed on the stator convex portion. Therefore, the plunger concave shape in this example has a plunger flat part 1321 around the central axis, and the stator convex shape also has a stator flat part 1121 around the central axis.

A washer 135 is disposed on this plunger flat portion 1321 of the plunger facing surface 132 . The washer 135 is made of a non-magnetic material such as SUS304. Therefore, the plunger 130 attracted to the stator core 110 when the coil 102 is energized does not continue to be attracted by the residual magnetism between the plunger facing surface 132 and the stator facing surface 112 even when the coil 102 is not energized.

A cylindrical sleeve 136 is disposed between the plunger cylindrical portion 131 and the coil bobbin 101. The plunger 130 is used to smoothly reciprocate around the inner circumference of the coil bobbin 101, and is made of metal made of non-magnetic material. Similar to the washer 135 described above, SUS304 or the like is used. The sleeve 136 is press-fitted and fixed to the inner circumference of the coil bobbin 101.

Next, the operation of the electromagnetic actuator 100 having the above configuration will be explained using FIGS. 3 and 4. In this example, plunger 130 is rotatably connected to link 210 of dog clutch mechanism 200. The dog clutch mechanism 200 engages and disengages a movable clutch plate 220 having movable dog teeth 221 and a fixed clutch plate 230 having fixed dog teeth 231.

As shown in FIG. 3, when the coil 102 is de-energized and the plunger 130 is displaced in the second direction (to the left in FIG. 3), the movable clutch plate 220 is separated from the fixed clutch plate 230. In the example of FIG. 3, the plunger 130 is displaced in the second direction due to the mechanical structure of the dog clutch mechanism 200, but the plunger 130 may be moved in the second direction using a plunger spring (not shown). good.

When the movable clutch plate 220 is engaged with the fixed clutch plate 230, as shown in FIG. 4, the coil 102 is energized to displace the plunger 130 in the first direction (rightward in FIG. 4). The displacement of plunger 130 is transmitted to movable clutch plate 220 via link 210. Specifically, the link 210 rotates around a rotation support shaft 211, and the rotation support shaft 211 moves through an elongated hole 212 formed in the axial direction of the link 210, thereby fixing the movable dog tooth 221. It engages smoothly with the dog teeth 231.

The operation of the dog clutch mechanism 200 will be explained in terms of the magnetic attraction force caused by the energization of the coil 102. In the non-energized state of the coil 102 shown in FIG. 3, a predetermined stroke exists between the plunger 130 and the stator core 110, and this stroke corresponds to the magnetic gap A. The magnetic gap A is, for example, about 10 mm between the plunger facing surface 132 and the stator facing surface 112. Since the stator cylindrical portion 113 extends from the stator cylindrical portion 111 in the second direction, the magnetic gap A between the plunger facing surface 132 and the stator cylindrical portion 113 is reduced.

When coil 102 is energized, a magnetic circuit is created between yoke 150, plate 151, stator core 110, and plunger 130. Since a magnetic gap A is created between the inner stator core 110 of the magnetic circuit and the plunger 130, the magnetic flux acts in a direction to narrow this magnetic gap A, and a magnetic attraction force is generated. However, if the magnetic gap A is too wide, the density of magnetic flux flowing between the magnetic gaps A will decrease, and the magnetic attraction force will decrease. Depending on the urging force of the plunger spring, there is a possibility that the plunger 130 cannot be attracted.

In the present disclosure, as shown immediately after the excitation of the coil 102 in FIG. 5, the stator cylindrical portion 113 extends in the second direction to reduce the magnetic gap A. Therefore, immediately after the coil 102 is energized, magnetic flux flows between the second direction end 1131 of the stator cylindrical portion 113 and the plunger facing surface 132 facing the second direction end 1131. As described above, since the second direction end portion 1131 narrows the magnetic gap A, the density of the magnetic flux flowing between the second direction end portion 1131 and the opposing plunger facing surface 132 becomes high, and the plunger 130 is connected to the stator core 110. Can be sucked to the side. Thereby, the magnetic attraction force between the second direction end portion 1131 and the opposing plunger facing surface 132 reliably exceeds the biasing force of the plunger spring. Note that although the second direction end portion 1131 has an edge shape in FIG. 5, the second direction end portion 1131 does not have to have an edge shape. Even if the shape of the second direction end portion 1131 is flat, the magnetic attraction force does not change much.

As shown at the beginning of the movement of the plunger 130 in FIG. 5, when the plunger 130 moves in the first direction, the magnetic gap A between the plunger facing surface 132 and the stator facing surface 112 narrows, and accordingly, the magnetic gap A between the plunger facing surface 132 and the stator facing surface 112 narrows. The magnetic flux density between the surface 112 and the surface 112 increases. That is, the magnetic attraction force that attracts plunger 130 to stator core 110 becomes higher.

However, as shown in the latter half of the movement of the plunger 130 in FIG. 5, when the movement of the plunger 130 in the first direction reaches a predetermined amount, the magnetic flux flowing from the plunger cylindrical part 131 of the plunger 130 to the stator cylindrical part 113 increases. . The magnetic flux flowing from the plunger cylindrical portion 131 to the stator cylindrical portion 113 simply flows in the radial direction and does not have an axial vector. Therefore, the magnetic flux flowing from the plunger cylindrical portion 131 to the stator cylindrical portion 113 does not contribute to the magnetic attraction force. In other words, when the movement of the plunger 130 in the first direction exceeds a predetermined amount, although the magnetic gap A between the plunger facing surface 132 and the stator facing surface 112 becomes narrower, the magnetic gap A between the plunger facing surface 132 and the stator facing surface 112 becomes smaller. The magnetic flux flowing through the magnetic gap A will be reduced. Therefore, the narrowing of the magnetic gap A and the reduction of the magnetic flux conflict with each other, and the overall magnetic attraction force gradually increases and remains approximately constant.

In FIG. 6, the relationship between the magnetic gap A and the magnetic attraction force of the present disclosure is shown as X1. As explained above, a magnetic attraction force is generated by the magnetic gap between the second direction end portion 1131 of the stator cylindrical portion 113 and the plunger cylindrical portion 131 immediately after the coil 102 with a large stroke is energized ( W1 point). At the beginning of the movement of the plunger 130, as the stroke becomes smaller, the magnetic flux density increases and the magnetic attraction force also increases (point W2). However, in the latter half of the movement of the plunger 130, as a result of the magnetic flux flowing into the stator cylindrical portion 113, the increase in the magnetic attraction force is suppressed (point W3).

Comparative Example Y shown in FIG. 6 is an electromagnetic actuator 100 that does not include the stator cylindrical portion 113, as shown in FIG. Without the stator cylindrical portion 113, immediately after the coil 102 is energized, the stroke is too large and the magnetic attraction force is small, making it difficult to move the plunger 130 (point Z1). Once the plunger 130 starts moving, the magnetic attraction force increases exponentially as the magnetic gap A decreases (point Z2). Therefore, there is a possibility that the plunger 130 will collide with the stator core 110 with a large magnetic attraction force (point Z3). In contrast, in the present disclosure, as described above, the magnetic attraction force increases gradually.

However, the stator cylindrical portion 113 of the present disclosure does not allow magnetic flux to flow unlimitedly. That is, when the magnetic flux flows toward the stator cylindrical portion 113, the plunger 130 cannot be attracted because the magnetic flux flowing toward the stator cylindrical portion 113 has no vector in the first direction, as described above. Therefore, the magnetic flux flowing through the stator cylindrical portion 113 is set to be magnetically saturated by a certain amount. The degree of magnetic saturation is adjusted according to the stroke of the plunger 130.

As shown in FIG. 8, when the stroke is about 5 mm, it is possible to attract the plunger 130 in the first direction by the magnetic attraction force between the stator facing surface 112 and the plunger facing surface 132. Therefore, the magnetic attraction force required of the stator cylindrical portion 113 to start attracting the plunger 130 may be small. Conversely, if the magnetic flux flows toward the stator cylindrical portion 113 after the plunger 130 moves, the magnetic attraction force will be reduced. In addition, in FIG. 8 and FIG. 9 described later, the magnetic flux density is shown by arrows, and cross-sectional hatching is omitted to make the arrows easier to understand.

Therefore, when the stroke is small, the magnetic flux flowing within the stator cylindrical portion 113 is required to reach magnetic saturation early. Here, "early magnetic saturation" means that the magnetic flux of the stator cylindrical part 113 is saturated at a stage when the amount of overlap between the plunger cylindrical part 131 and the stator cylindrical part 113 is small. For example, when the excitation force of the coil 102 is from several tens of newtons to several hundred newtons and the outer diameter of the coil 102 is about 60 mm, the wall thickness of the stator cylindrical portion 113 may be about 0.5 mm.

On the other hand, as shown in FIG. 9, when the stroke is about 10 mm, it is necessary to increase the magnetic attraction force that attracts the plunger 130 immediately after the coil 102 is energized. That is, a predetermined amount of magnetic flux needs to flow between the plunger facing surface 132 and the second direction end 1131 of the stator cylindrical portion 113. Furthermore, as described above, it is undesirable that the magnetic attractive force between the stator facing surface 112 and the plunger facing surface 132 becomes too high in the latter stage of the movement of the plunger 130. Therefore, when the stroke is large, a certain amount of magnetic flux is required to flow through the stator cylindrical portion 113. When the excitation force of the above-mentioned coil 102 is from several tens of newtons to several hundred newtons and the outer diameter of the coil 102 is about 60 mm, the wall thickness of the stator cylindrical portion 113 is preferably made thick to about 1 mm. .

FIG. 10 shows the relationship between magnetic attraction force and stroke. In FIG. 10, X2 indicates the tendency of the magnetic attraction force of the electromagnetic actuator 100 shown in FIG. 8 with a stroke of about 5 mm. And, X3 shows the tendency of the magnetic attraction force of the electromagnetic actuator 100 shown in FIG. 9 with a stroke of about 10 mm. Further, Y is a comparative example, which shows the tendency of an electromagnetic actuator that does not include the stator cylindrical portion 113, as shown in FIG. As shown in FIG. 10, by adjusting the degree of magnetic saturation of the magnetic flux flowing inside the stator cylindrical portion 113, it becomes possible to correspond to the required stroke of the electromagnetic actuator.

In the example of FIG. 5, the second direction end portion 1131 of the stator cylindrical portion 113 has an edge shape in which the wall thickness decreases as it goes in the second direction. However, for reasons such as moldability, it is of course possible to have a cylindrical shape without an edge portion as shown in FIGS. 1 and 2. As described above, even if the shape does not have an edge portion, the magnetic attraction force does not change much.

Further, in the examples shown in FIGS. 1 and 2, the stator facing surface 112 has a convex stator shape, but as shown in FIG. 11, it may have the opposite concave shape. That is, the stator cylindrical portion 111 may have a tapered shape in which the diameter decreases from the end surface in the second direction toward the first direction. In this example, the shape of the stator facing surface 112 shown in FIG. 11 is referred to as a stator concave shape. Even with this stator concave shape, the stator flat portion 1121 may be formed around the central axis and the washer 135 may be disposed.

When the stator facing surface 112 has a concave stator shape, the plunger facing surface 132 also has a shape corresponding to the shape of the stator facing surface 112. In this case, the plunger facing surface 132 has a tapered shape whose diameter decreases from the end surface of the plunger cylindrical portion 131 in the second direction toward the first direction. In this example, the shape of the plunger facing surface 132 shown in FIG. 11 is called a plunger convex shape.

In this way, even if the concave and convex shapes of the stator facing surface 112 and the plunger facing surface 132 are reversed, the effect of the stator cylindrical portion 113 shown in FIGS. 1 and 2 is the same. That is, as explained in the example of FIG. 5, even if the stator facing surface 112 has a stator concave shape and the plunger facing surface 132 has a plunger convex shape, the stator cylindrical portion 113 prevents the magnetic field between the stator core 110 and the plunger 130. The suction power can be adjusted to an appropriate value. This is the same even if the stator facing surface 112 has a stator convex shape and the plunger facing surface 132 has a plunger concave shape as in the example of FIG. 1, or the opposite concave shape as shown in FIG.

Further, it is desirable that the shapes of the stator facing surface 112 and the plunger facing surface 132 be a combination of a concave shape and a convex shape in order to arrange the flow of magnetic flux between the stator core 110 and the plunger 130. However, if it is difficult to form a concave or convex shape due to manufacturing requirements, the present disclosure does not exclude that both the stator facing surface 112 and the plunger facing surface 132 may be made planar. That is, it is not excluded that the plunger plane part 1321 and the stator plane part 1121 are formed not only around the central axis but also over the entire surface.

Further, in the above example, the stator cylindrical portion 113 is formed integrally with the stator core 110, but it is also possible to form the stator core 110 and the stator cylindrical portion 113 as separate members. In this case, as shown in FIG. 12, the stator cylindrical portion 113 is a circular tube made of a magnetic material, and SUS430 or iron material is used. The stator cylindrical portion 113 is press-fitted onto the outer periphery of the stator cylindrical portion 111 and fixed thereto.

Furthermore, the plunger 130 may be provided with a cylindrical portion. That is, the basic structure is the same as that shown in FIG. 12, and as shown in FIG. 13, it can also be formed by using a plunger cylindrical portion 133 as a separate member. In this case, the plunger cylindrical portion 133 is press-fitted onto the outer periphery of the plunger cylindrical portion 131 of the plunger 130 . Then, when the plunger 130 moves in the first direction, the plunger cylindrical portion 133 comes to be located on the outer periphery of the stator cylindrical portion 111.

Even when the plunger 130 is formed with the plunger cylindrical portion 133, the operation is the same as that shown in FIG. 5. That is, when the coil 102 is not energized, there is a gap between the first direction end 1331 of the plunger cylindrical portion 133 and the stator cylindrical portion 111. Then, immediately after the coil 102 is energized, a magnetic attraction force is generated in the gap between the first direction end portion 1331 and the stator columnar portion 111. As the plunger 130 moves, the plunger cylindrical part 133 is positioned on the outer periphery of the stator cylindrical part 111 to form a magnetic circuit, thereby increasing the amount of magnetic attraction between the plunger facing surface 132 and the stator facing surface 112. to prevent it from becoming excessive. At the same time, the magnetic flux in the plunger cylindrical portion 133 is also saturated at a predetermined density, and it is possible to prevent the amount of magnetic attraction between the plunger facing surface 132 and the stator facing surface 112 from becoming too small.

In the embodiment described above, a washer 135 made of a non-magnetic material is interposed between the plunger facing surface 132 and the stator facing surface 112. This is preferable because it can prevent the plunger 130 from becoming difficult to separate from the stator core 110 due to residual magnetism. However, it is possible to arrange the plunger 130 and the stator core 110 so that they do not come into contact with each other by providing a locking portion for the plunger 130 or the like. In that case, the washer 135 made of non-magnetic material can be made unnecessary.

Further, in the example described above, the electromagnetic actuator 100 of the present disclosure was used as a drive device for the dog clutch mechanism 200, but the electromagnetic actuator 100 of the present disclosure has various uses other than the dog clutch mechanism 200, and can be used for other clutch mechanisms and various It can be used as an actuator to open and close valves.

For example, when used in a sealed valve, plunger 130 communicates with the sealed valve. The sealing valve is a valve that opens and closes a passage connecting the fuel tank and the canister. A sealing valve opens a passage before refueling and allows the evaporated fuel and high-pressure air in the fuel tank to flow toward the canister. Normally, the plunger 130 is biased in the second direction by a plunger spring to close the valve. The body seals the passageway.

That is, the sealing valve is displaced by the plunger spring in the second direction that separates the plunger 130 from the stator core 110. Then, the plunger 130 is displaced in the second direction by the plunger spring, so that the valve body is seated on the valve seat and closes the passage. Further, the state in which the valve body is seated on the valve seat and closes the passage is a state in which the coil 102 is not energized. However, even when used in a valve, it is of course possible to separate the plunger 130 from the stator core 10 using the pressure of the working fluid. Therefore, the plunger spring is not essential, and is not shown in this example.

In addition, the electromagnetic actuator of the present disclosure can be used to switch between locking and unlocking a member, and can also be used to adjust the angle of a member. It can also be used for shades that control the low/high light distribution of discharge type headlights, levelers that adjust the irradiation direction up and down, and AFS that adjust the irradiation direction left and right. Further, it can also be used to operate a driven body such as a shift lever lock device of a vehicle equipped with an automatic transmission (AT vehicle).

Further, the materials and sizes described above are merely examples, and can be appropriately selected depending on the required performance. The disclosure in this specification, drawings, etc. is not limited to the illustrated embodiments. The disclosure includes the illustrated embodiments and variations thereon by those skilled in the art.

100 Electromagnetic actuator 102 Coil 110 Stator core 111 Stator cylindrical portion 112 Stator opposing surface 113 Stator cylindrical portion 130 Plunger 131 Plunger cylindrical portion 132 Plunger opposing surface 133 Plunger cylindrical portion

Claims (6)

A coil that is excited when energized,
A stator core made of magnetic material that is placed in the magnetic circuit when the coil is energized,
When the coil is energized, the coil is disposed opposite to the stator core through a magnetic gap in a magnetic circuit, and when the coil is energized, it moves in a first direction toward the stator core by magnetic attraction, and when the coil is not energized, the coil is moved in a first direction toward the stator core. a plunger made of a magnetic material that moves in a second direction away from the stator core;
The stator core includes a stator facing surface that faces the plunger through the magnetic gap, a stator cylindrical part located on the first direction side of the stator facing surface, and a stator cylindrical part located from the outer periphery of the stator cylindrical part to the second stator cylindrical part. a stator cylindrical portion extending in the direction;
The plunger includes a plunger facing surface that faces the stator core through the magnetic gap, and a plunger cylindrical part that is located on the second direction side of the plunger facing surface and can face the inner periphery of the stator cylindrical part. and
When the coil is not energized, there is a space between the end of the stator cylindrical part in the second direction and the plunger cylindrical part, and between the stator facing surface and the plunger facing surface. a magnetic gap is formed in the second direction;
When the coil is energized, the outer periphery of the plunger cylindrical part faces the inner periphery of the stator cylindrical part, and there is a gap between the inner periphery of the stator cylindrical part and the outer periphery of the plunger cylindrical part and the stator opposing surface. An electromagnetic actuator, wherein a magnetic circuit is formed between the plunger and the plunger facing surface. A coil that is excited when energized,
A stator core made of magnetic material that is placed in the magnetic circuit when the coil is energized,
When the coil is energized, the coil is disposed opposite to the stator core through a magnetic gap in a magnetic circuit, and when the coil is energized, it moves in a first direction toward the stator core by magnetic attraction, and when the coil is not energized, the coil is moved in a first direction toward the stator core. a plunger made of a magnetic material that moves in a second direction away from the stator core;
The plunger includes a plunger facing surface that faces the stator core through the magnetic gap, a plunger cylindrical part located on the second direction side of the plunger facing surface, and a plunger cylindrical part located on the first side from the outer periphery of the plunger cylindrical part. a plunger cylindrical portion extending in the direction;
The stator core includes a stator facing surface that faces the plunger through the magnetic gap, and a stator cylindrical part that is located on the first direction side of the stator facing surface and can face the inner periphery of the plunger cylindrical part. and
When the coil is not energized, there is a space between the end of the plunger cylindrical portion in the first direction and the stator cylindrical portion and between the stator facing surface and the plunger facing surface. a magnetic gap is formed in the second direction;
When the coil is energized, the outer periphery of the stator cylindrical part faces the inner periphery of the plunger cylindrical part, and there is a gap between the inner periphery of the plunger cylindrical part and the outer periphery of the stator cylindrical part and the stator opposing surface. An electromagnetic actuator, wherein a magnetic circuit is formed between the plunger and the plunger facing surface. The plunger facing surface has a plunger concave shape whose diameter decreases from the end surface in the first direction toward the second direction,
The electromagnetic actuator according to claim 1 or 2, wherein the stator facing surface has a stator convex shape whose diameter decreases from the end surface in the first direction toward the second direction. The plunger facing surface has a plunger convex shape whose diameter increases from the end surface in the first direction toward the second direction,
The electromagnetic actuator according to claim 1 or 2, wherein the stator facing surface has a stator concave shape whose diameter increases from the end surface in the first direction toward the second direction. A plunger flat portion is formed around the central axis of the plunger facing surface,
The electromagnetic actuator according to claim 1 or 2, wherein a stator flat portion corresponding to the plunger flat portion is formed around a central axis of the stator facing surface. The electromagnetic actuator according to claim 1 or 2, wherein a washer made of a non-magnetic material is disposed on either the stator facing surface or the plunger facing surface.

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