JP6658701B2 - Magnetic actuator - Google Patents

Description

  The present invention relates to a magnetic actuator capable of changing a relative position between two members.

  2. Description of the Related Art Conventionally, a magnetic actuator capable of changing a relative position between two members using an electromagnet has been known. For example, Patent Document 1 discloses a self-holding type rotary solenoid. A permanent magnet is provided on the rotor of this solenoid. For example, a plurality of permanent magnets are provided so that the magnetic poles are reversed around the circumference. The stator facing the rotor is provided with salient magnetic poles and coils wound therearound. By energizing the coil, the magnetic material is magnetized and attracts one of the permanent magnets on the rotor. Thereafter, even if the energization of the coil is stopped, the salient poles of the magnetic material and the permanent magnet attract each other, and the relative position is maintained. When the direction of current is further reversed, the salient poles move to permanent magnets of other magnetic poles than the permanent magnets that have been attracted up to that time.

JP 2017-17160 A

  By the way, when a plurality of permanent magnets are provided such that the magnetic poles are reversed, it may be difficult to control the movement of the bending. In the magnetic actuator shown in FIG. 16, a plurality of permanent magnets 102A to 102E are provided on the inner peripheral surface of the stator 100 (outer peripheral ring) so that the magnetic poles are reversed along the circumferential direction. In addition, a salient pole 106 is provided on the outer peripheral surface of the rotor 104 (the inner peripheral ring) to face this.

  For example, the opposite pole of the salient pole 106 facing the stator 100 is magnetized to the N pole to face the S pole 102C of the stator 100. Further, thereafter, when the direction of energization of the coil (not shown) is reversed and the opposite pole of the salient pole 106 facing the stator 100 is reversed to the S pole, the salient pole 106 is switched to the N pole adjacent to the S pole 102C. Moving. At this time, when the S pole 102C and the salient pole 106 face each other, that is, when the central axes of both are aligned along the radial direction, the salient pole 106 moves to any of the adjacent N poles 102B and 102D. There is a possibility that the movement of the salient pole 106 may be difficult to control. Accordingly, it is an object of the present invention to provide a magnetic actuator capable of controlling the movement of a salient pole to be excited with higher accuracy than in the past.

  The present invention relates to a magnetic actuator. The actuator includes a bobbin, a magnet rotor, and a salient pole rotor. The bobbin has a winding drum portion around which a coil is wound, and a pair of flanges provided at both ends in the central axis direction of the winding drum portion and having a diameter larger than that of the winding drum portion. The magnet rotor is provided apart from the bobbin in the radial direction, a ring-shaped first yoke, and a plurality of permanent magnets provided on the inner peripheral surface of the first yoke and whose magnetic poles are reversed along the circumferential direction. And The salient pole rotor is provided between at least one of the pair of flanges of the bobbin and the magnet rotor, apart from each other, and is provided with an annular second yoke and an outer peripheral surface of the second yoke. And salient poles. An angle limiter mechanism is provided on the inner peripheral surface of the magnet rotor and the outer peripheral surface of the salient pole rotor to prevent a facing arrangement in which the center positions of the salient poles and the permanent magnets are aligned along the radial direction.

  In the above invention, the angle limiter mechanism may include a groove portion provided on the outer peripheral surface of the salient pole rotor and having a relatively reduced diameter, and a plate protruding from the inner peripheral surface of the magnet rotor to the inside of the groove portion. Good.

  In the above invention, a plurality of grooves and plates are provided along the circumferential direction, one salient pole is provided between a pair of adjacent grooves, and a pair of permanent magnets is provided between a pair of adjacent plates. Is also good.

  In the above invention, the width of the groove in the circumferential direction of the groove may be smaller than the pitch between the center positions of the pair of permanent magnets in the circumferential direction.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to perform movement control of the salient pole which is an excitation target with higher precision than before.

FIG. 2 is a partial cross-sectional perspective view illustrating a magnetic actuator according to the embodiment. It is a side view which illustrates a part of magnetic actuator concerning this embodiment. FIG. 4 is a diagram (at the time of disengagement) when the magnetic actuator according to the embodiment is mounted on a clutch mechanism. FIG. 4 is a diagram (at the time of engagement) when the magnetic actuator according to the embodiment is mounted on a clutch mechanism. It is a figure explaining the magnetic pole of a salient pole rotor at the time of coil energization (negative energization). It is a figure explaining the magnetic pole of a salient pole rotor at the time of coil energization (positive energization). It is a figure which illustrates the situation when the counterclockwise movement of the salient pole rotor is stopped by the angle limiter mechanism. It is a figure which illustrates a mode when the clockwise movement of the salient pole rotor is stopped by the angle limiter mechanism. It is a figure explaining the behavior of the magnetic actuator in the early stage at the time of the coil energization. It is a figure explaining the behavior of the magnetic actuator at the end of the time of the coil energization. It is a figure explaining the behavior of the magnetic actuator at the time of coil non-energization. It is a figure explaining the behavior of the magnetic actuator in the early stage at the time of coil negative energization. It is a figure explaining the behavior of the magnetic actuator in the last stage at the time of coil negative energization. 4 is a graph showing changes in torque and relative angle of the magnetic actuator according to the embodiment when no current is applied, when positive current is applied, and when negative current is applied. FIG. 5 is a diagram illustrating a flow of a magnetic flux when no current is supplied to the magnetic actuator according to the embodiment. FIG. 9 is a diagram illustrating a magnetic actuator according to the related art.

  FIG. 1 illustrates a perspective sectional view of a magnetic actuator 10 according to the present embodiment. FIG. 2 illustrates a partial side view of the magnetic actuator 10. Note that FIGS. 1 to 13 and FIG. 15 show three axes orthogonal to each other. Of these three axes, the X axis is an axis parallel to the central axis of the magnetic actuator 10. The Y axis and the Z axis are both orthogonal to the X axis. When the X axis coincides with the center axis of the magnetic actuator, the Y axis and the Z axis extend in the radial direction.

  The magnetic actuator 10 includes a bobbin 12, a magnet rotor 14, a salient pole rotor 16, and a controller 18. As will be described later, the magnetic actuator 10 can change the relative position (relative angle) between the magnet rotor 14 and the salient pole rotor 16. 1 to 15, the salient pole rotor 16 and the magnet rotor 14 are kept apart from the bobbin 12, and the salient pole rotor 16 and the magnet rotor 14 are kept apart from each other. On the other hand, the illustration of a mechanism such as a bearing that enables these rotors to rotate is omitted.

  The bobbin 12 includes an annular winding body 22 around which the coil 20 is wound, and a pair of annular flanges 24A and 24B provided at both ends in the center axis direction. Since the bobbin 12 also has a function as a yoke through which a magnetic flux generated by energization of the coil 20 passes, the bobbin 12 is made of a highly permeable material such as a low carbon steel or a silicon steel plate. The bobbin 12 is fixed by a fixing member such as a case (not shown).

  The diameter of the pair of flanges 24 </ b> A, 24 </ b> B is expanded from the winding drum 22. Here, as illustrated in FIG. 1, the pair of flanges 24B have a larger diameter expansion width than the other flange 24A. For example, the radial width of the flange 24B is configured to be substantially equal to the sum of the radial width of the flange 24A and the radial width of the second yoke 26 of the salient pole rotor 16.

  The coil 20 is wound around the winding drum 22 of the bobbin 12. For example, as illustrated in FIG. 5, the coil 20 is configured by a stranded wire composed of a plurality of strands. Further, wiring is drawn out of the magnetic actuator 10 via the bobbin 12 from the coil 20 and connected to the control unit 18.

  The magnet rotor 14 is provided radially outside of the bobbin 12 so as to be separated from the bobbin 12. The magnet rotor 14 includes an annular first yoke 28, a plurality of permanent magnets 30, and a plate 32 (stopper plate).

  The first yoke 28 is an annular member, and has a function as a path (magnetic path) of a magnetic flux generated when the coil 20 is energized. The first yoke 28 is made of a highly magnetically permeable material such as a low carbon steel or a silicon steel plate.

  On the inner peripheral surface of the first yoke 28, a permanent magnet 30 and a plate 32 are provided. As shown in FIG. 2, the permanent magnet 30 is provided on the inner peripheral surface of the first yoke 28 so that the magnetic poles are reversed along the circumferential direction.

  In and after FIG. 2, the magnetic poles facing the outer peripheral surface of the salient pole rotor 16 are described in these permanent magnets 30N1, 30S1, 30N2, and 30S2. Hereinafter, a magnetic pole facing the outer peripheral surface of the salient pole rotor 16 will be simply referred to as a facing magnetic pole of the permanent magnet 30 as appropriate. For example, the opposing magnetic poles of the permanent magnets 30S1 and 30S2 are S poles, and the opposing magnetic poles of the permanent magnets 30N1 and 30N2 are N poles.

  The plate 32 is provided between the plurality of permanent magnets 30. The plate 32 protrudes radially inward from the inner peripheral surface of the magnet rotor 14. Further, the plate 32 may be provided so as to protrude into the groove 34 of the salient pole rotor 16. In order to enable such a configuration, the protruding length L1 of the plate 32 is determined by the radial length L2 of the salient pole 36 of the salient pole rotor 16 and the gap width L3 between the magnet rotor 14 and the salient pole rotor 16. May be exceeded (L1> L2 + L3). As described later, the plate 32 and the groove 34 function as an angle limiter mechanism for preventing the salient poles 36 of the salient pole rotor 16 and the permanent magnets 30 of the magnet rotor 14 from facing each other.

  A plurality of plates 32 are provided on the inner peripheral surface of the magnet rotor 14 along the circumferential direction. Here, a pair of permanent magnets 30N, 30S may be provided between a pair of adjacent plates 32, 32. In this manner, by separating the pair of permanent magnets 30N and 30S, which are reversing magnetic poles, by the plate 32, the relative movement control of the magnet rotor 14 and the salient pole rotor 16 can be reliably performed.

  The salient pole rotor 16 is a substantially annular member provided between the bobbin 12 and the magnet rotor 14. More specifically, a salient pole rotor 16 is provided between the flange 24 </ b> A of the bobbin 12 and the magnet rotor 14 so as to be separated from the two.

  The salient pole rotor 16 includes a second yoke 26, a salient pole 36, and a groove 34. The second yoke 26 is an annular member having a function as a path (magnetic path) of a magnetic flux generated when the coil 20 is energized. The second yoke 26 is made of, for example, a high magnetic permeability material such as a low carbon steel or a silicon steel plate. When the second yoke 26 is formed integrally with the salient poles 36, these may be made of a ferromagnetic material such as iron or ferrite.

  A plurality of salient poles 36 are formed on the outer peripheral surface of the second yoke 26 along the circumferential direction. The salient poles 36 protrude radially outward from the outer peripheral surface of the second yoke 26. As described later, the salient pole 36 attracts one of the permanent magnets 30N and 30S even when the energization of the coil 20 is cut off. The salient poles 36 are made of a ferromagnetic material such as iron or ferrite.

  Further, it is preferable that the circumferential width W1 of the salient pole 36 is a width that does not straddle the pair of permanent magnets 30N and 30S. For example, the salient pole 36 is formed such that the width W1 of the salient pole 36 is smaller than the width W2 from one end to the other end of the pair of permanent magnets 30N, 30S.

  The groove 34 is provided on the outer peripheral surface of the salient pole rotor 16, and is reduced in diameter relative to the outer peripheral surface. A plurality of grooves 34 are formed along the circumferential direction. Further, as described above, the groove 34 and the plate 32 are positioned so that the plate 32 of the magnet rotor 14 enters the groove 34.

  The groove portion 34 is formed such that the groove width P2 along the circumferential direction of the groove portion 34 is less than the pitch P1 between the center positions along the circumferential direction of the pair of permanent magnets 30N, 30S. In addition, one salient pole 36 may be provided between a pair of adjacent grooves 34, 34. By doing so, it is possible to prevent the salient pole 36 from being directly opposed to the permanent magnet 30N or the permanent magnet 30S.

  Note that, as described above, the facing of the salient pole 36 and the permanent magnet 30 indicates an arrangement in which the circumferential center positions of both are aligned along the radial direction.

  The magnet rotor 14 and the salient pole rotor 16 are rotatable with respect to the bobbin 12 as a fixed member by a support mechanism such as a bearing (not shown). Further, the magnet rotor 14 and the salient pole rotor 16 are relatively rotatable within an allowable range of the plate 32 and the groove 34 as the angle limiter mechanism.

  The magnetic actuator 10 provided with such a mechanism can be applied to a clutch mechanism as exemplified in FIGS. 3 and 4, for example. For example, an outer peripheral ring 37 is provided radially outside the magnet rotor 14 so as to be separated from the magnet rotor 14. Further, a notch is provided on the outer peripheral surface of the first yoke 28 of the magnet rotor 14. The notch is a slope along the circumferential direction. With such a structure, a gap 39 is formed around the notch, the width of which becomes narrower as it advances clockwise.

  A roller 38 is provided in the gap 39. The roller 38 is connected to the salient pole rotor 16 by an arm 40. In order to make the roller 38 movable in the radial direction, the arm 40 may be provided with a slit cut in the axial direction, and the roller 38 may be held by inserting a rotation support shaft of the roller 38 into the slit.

  For example, when the magnet rotor 14 and the salient pole rotor 16 are rotating counterclockwise (synchronous rotation), the salient pole rotor 16 is delayed (clockwise) with respect to the magnet rotor 14 by magnetic pole reversal described later. Displace. Accordingly, as shown in FIG. 4, the roller 38 meshes (engages) with the outer peripheral ring 37. As a result, the outer peripheral ring 37 rotates synchronously with the magnet rotor 14 and the salient pole rotor 16.

  Returning to FIG. 1, the control unit 18 controls the relative position (relative angle) between the magnet rotor 14 and the salient pole rotor 16 by controlling the current flowing through the coil 20. The control unit 18 may be composed of, for example, a computer, and the CPU, the storage unit, and the device / sensor interface are connected to each other via an internal bus. For example, in accordance with an engagement / disengagement instruction from the outside, the control unit 18 determines whether the coil 20 is energized (non-energized) and the energizing direction (positive energization / negative energization).

  FIGS. 5 and 6 illustrate the flow of magnetic flux in the cross-sectional plane of the magnetic actuator 10 shown in FIG. As illustrated in FIG. 5, when a current is supplied to the coil 20 in a clockwise direction, a magnetic flux as indicated by an arrow in the figure passes through the bobbin 12, the salient pole rotor 16, and the magnet rotor 14. With the passage of the magnetic flux, the salient pole rotor 16 has an N pole on the outer periphery and an S pole on the inner periphery.

  FIG. 6 exemplifies a magnetic flux when the direction of current is reversed. At this time, a magnetic flux as indicated by an arrow in the figure passes through the bobbin 12, the magnet rotor 14, and the salient pole rotor 16. With the passage of the magnetic flux, the salient pole rotor 16 becomes an S pole on the outer periphery and an N pole on the inner periphery.

  FIG. 7 illustrates the behavior of the magnet rotor 14 and the salient pole rotor 16 when the opposing magnetic pole of the salient pole 36 is the N pole. At this time, the salient pole 36 is separated from the permanent magnet 30N2 whose opposite magnetic pole is the N pole and attracts the permanent magnet 30S1 whose opposing magnetic pole is the S pole. Accordingly, the salient pole rotor 16 moves counterclockwise with respect to the magnet rotor 14.

  At this time, the configuration described above, that is, the configuration is such that the groove width P2 of the groove portion 34 is less than the pitch P1 between the center positions of the pair of permanent magnets 30N, 30S, and the salient pole 36 is provided between the adjacent groove portions 34, 34. Before the salient pole 36 faces the permanent magnet 30S1, the side wall surface of the groove 34 contacts the plate 32 as shown by the center line C1 of the permanent magnet 30S1 and the center line C2 of the salient pole 36. To prevent further movement.

  As described above, since the salient pole 36 is offset toward the permanent magnet 30N2, when the opposing magnetic pole of the salient pole 36 is inverted from the N pole to the S pole, the salient pole 36 is exclusively drawn to the permanent magnet 30N2.

  FIG. 8 illustrates the behavior of the magnet rotor 14 and the salient pole rotor 16 when the opposing magnetic pole of the salient pole 36 is the S pole. At this time, the salient pole 36 is separated from the permanent magnet 30S1 whose opposite magnetic pole is the S pole and attracts the permanent magnet 30N2 whose opposing magnetic pole is the N pole. Accordingly, the salient pole rotor 16 moves clockwise with respect to the magnet rotor 14.

  At this time, as shown in FIG. 7, as shown by the center line C1 of the permanent magnet 30N2 and the center line C2 of the salient pole 36, before the salient pole 36 faces the permanent magnet 30N2, the side wall surface of the groove 34 is It contacts the plate 32 to prevent further movement. As described above, since the salient pole 36 is offset toward the permanent magnet 30S1, when the opposite magnetic pole of the salient pole 36 is inverted from the S pole to the N pole, the salient pole 36 is exclusively drawn to the permanent magnet 30S1.

  The operation of the magnetic actuator 10 according to the present embodiment will be described with reference to FIGS. FIGS. 2, 9 to 13 illustrate the respective operations of the magnetic actuator 10, and FIG. 14 shows the torque associated with each operation and the relative angle between the magnet rotor 14 and the salient pole rotor 16. In the graph of FIG. 14, the horizontal axis represents the relative angle, and the vertical axis represents the torque. In addition, the counterclockwise torque is positive, and the clockwise angle change is positive.

  In addition, the graph of FIG. 14 shows the characteristic curve when no current flows through the coil 20 when no current flows, the characteristic curve in the energized state (positive energization) of FIG. 6, and the characteristic curve in the energized state (negative energization) of FIG. Is illustrated.

  Referring to FIGS. 2 and 14, when salient pole 36 is arranged near permanent magnet 30S1 and when no power is supplied, permanent magnet 30S1 and salient pole 36 attract each other, and as a torque, salient pole rotor 16 is driven. It is biased in the counterclockwise direction (to the permanent magnet 30S1). This bias is retained by the plate 32. In this state, the magnet rotor 14 and the salient pole rotor 16 can be rotated synchronously.

  Next, referring to FIG. 9 and FIG. 14, when the coil 20 is energized positively, the opposite magnetic pole of the salient pole 36 becomes the S pole. Accordingly, the salient pole 36 is separated from the permanent magnet 30S1, and is attracted to the permanent magnet 30N2. FIG. 14 illustrates an example in which a negative (clockwise) torque is applied to the salient pole rotor 16 and the salient pole rotor 16 advances clockwise with respect to the magnet rotor 14.

  FIG. 10 shows the so-called end point at the time of positive energization, in which the side wall of the groove 34 abuts on the plate 32 and the further clockwise advance of the salient pole rotor 16 with respect to the magnet rotor 14 is stopped. The situation at the time is shown.

  11 and 14, when salient pole 36 is arranged near permanent magnet 30N2, and when no power is supplied, permanent magnet 30N2 and salient pole 36 attract each other, and the salient pole rotor is used as torque. 16 is biased in a clockwise direction. This bias is retained by the plate 32. In this state, the magnet rotor 14 and the salient pole rotor 16 can be rotated synchronously.

  Referring to FIGS. 12 and 14, when negative current is applied to coil 20, the opposite magnetic pole of salient pole 36 becomes an N pole. Along with this, the salient pole 36 separates from the permanent magnet 30N2 and is attracted to the permanent magnet 30S1. FIG. 14 illustrates an example in which a positive (counterclockwise) torque is applied to the salient pole rotor 16 and the salient pole rotor 16 advances counterclockwise with respect to the magnet rotor 14.

  FIG. 13 shows a so-called end point at the time of negative current application, in which the side wall of the groove portion 34 comes into contact with the plate 32 to stop the salient pole rotor 16 from proceeding further counterclockwise with respect to the magnet rotor 14. Is shown. Thereafter, the power supply to the coil 20 is cut off, and the process returns to FIG.

  In the magnetic actuator 10 according to the present embodiment, the magnetic flux passes through the bobbin 12 when energized, whereas the magnetic flux converges between the magnet rotor 14 and the salient pole rotor 16 without passing through the bobbin 12 when not energized. (Forming a loop). FIG. 15 shows the result of the simulation, in which the flow of magnetic flux when no current is supplied is indicated by arrows. As shown in this figure, the magnetic fluxes generated by the permanent magnets 30S and 30N pass through the salient pole rotor 16, but return to the magnet rotor 14 without reaching the bobbin 12. That is, the magnetic flux does not pass over the rotating body (the magnet rotor 14 and the salient pole rotor 16) and the fixed body (the bobbin 12).

  When a magnetic flux passes between the rotating body and the fixed body, the magnetic flux changes in accordance with a change in the gap between the rotating body and the fixed body, and an eddy current is generated. This eddy current may lead to drag loss of the rotating body. In the magnetic actuator 10 according to the present embodiment, since the magnetic flux does not pass between the rotating body and the fixed body, it is possible to suppress the above-described drag loss.

  Reference Signs List 10 magnetic actuator, 12 bobbin, 14 magnet rotor, 16 salient pole rotor, 18 control section, 20 coil, 22 winding drum section, 24A, 24B flange, 26 second yoke, 28 first yoke, 30 permanent magnet, 32 plate, 34 grooves, 36 salient poles.

Claims (4)

A winding drum portion around which a coil is wound, and a bobbin having a pair of flanges provided at both ends in the central axis direction of the winding drum portion and having a diameter larger than that of the winding drum portion,
A ring-shaped first yoke, which is provided apart from the bobbin in the radial direction and a plurality of permanent magnets provided on the inner peripheral surface of the first yoke and whose magnetic poles are reversed along the circumferential direction, A magnet rotor having
An annular second yoke is provided between at least one of the pair of flanges of the bobbin and the magnet rotor and is spaced apart therefrom, and a protrusion is provided on an outer peripheral surface of the second yoke. A salient pole rotor having poles;
With
A magnetic actuator provided on an inner peripheral surface of the magnet rotor and an outer peripheral surface of the salient pole rotor, an angle limiter mechanism for preventing the salient poles and the permanent magnets from being directly opposed to each other and arranged in a radial direction. . The magnetic actuator according to claim 1, wherein
The angle limiter mechanism,
A groove portion provided on the outer peripheral surface of the salient pole rotor and having a relatively reduced diameter,
A plate protruding from the inner peripheral surface of the magnet rotor to the inside of the groove,
A magnetic actuator comprising: The magnetic actuator according to claim 2, wherein
The groove and the plate are provided in plurality along the circumferential direction,
One salient pole is provided between a pair of adjacent grooves,
A pair of permanent magnets are provided between a pair of adjacent plates,
Magnetic actuator. The magnetic actuator according to claim 3, wherein
The magnetic actuator according to claim 1, wherein a width of the groove along a circumferential direction of the groove is less than a pitch between central positions of the pair of permanent magnets along the circumferential direction.