JP6644632B2 - Electromagnetic actuator, active vibration damping device and active vibration damping device - Google Patents

Description

  The present invention relates to a technique related to an electromagnetic actuator that generates an axial driving force by electromagnetic force between an inner shaft member and an outer housing member, and relates to an electromagnetic actuator and an active vibration damping device using the same. The present invention relates to a vibration isolator.

  2. Description of the Related Art Generally, in an active vibration damping device or vibration damping device called an active type, an electromagnetic actuator is employed to obtain a vibration driving force. As described in Japanese Patent Application Laid-Open No. 2011-109831, for example, an electromagnetic actuator is configured such that an outer housing member on which a coil member is mounted and an inner shaft member on which a magnet member is mounted are connected by an elastic member. Structure. Then, an electromagnetic force due to energization of the coil member acts on the magnet member, so that an axial driving force is exerted between the inner shaft member and the outer housing member.

  By the way, the magnet member provided on the inner shaft member generally includes a pair of annular yoke members formed of a ferromagnetic material on both sides in the axial direction of the annular permanent magnet as shown in Patent Document 1 described above. It is composed by overlapping. Further, the permanent magnet and the pair of annular yoke members are externally attached to the inner shaft member and assembled, and are fixed to the inner shaft member by a fastening member constituting a bolt-nut type fastening mechanism or the like. .

  Here, the use of the pair of annular yoke members is effective in securing the mass of the inner shaft member when tuning the actuator characteristics and the like, while reducing the size of the relatively expensive permanent magnet and reducing the cost. . In addition, the use of a pair of annular yoke members is also effective in securing the degree of freedom in setting the position and shape of the pole face for permanent magnets that are difficult to perform post-processing such as cutting and pressing and have a small degree of freedom in shape design. It is.

  However, in an electromagnetic actuator having a conventional structure as described in Patent Document 1, a relatively small-diameter bolt is used as the inner shaft member. Therefore, in the permanent magnet or the annular yoke member, the outer diameter dimension required to form the magnetic pole surface close to the coil member mounted on the outer housing member or to secure the mass of the magnet member is reduced. If it is set, the permanent magnet and the annular yoke member are inevitably thickened in the radial direction. In particular, permanent magnets are manufactured by special processing using specific materials, so if thick permanent magnets with a large mass are required, the manufacture of the target electromagnetic actuator becomes difficult, resulting in high cost. Is also a problem.

JP 2011-109831 A

  The present invention has been made in view of the above circumstances, and a problem to be solved is to secure the outer diameter of the permanent magnet in the magnet member attached to the inner shaft member while maintaining the outer diameter of the permanent magnet. It is an object of the present invention to provide an electromagnetic actuator having a novel structure that can set a mass to be small.

  Hereinafter, embodiments of the present invention made to solve such problems will be described. The components employed in each of the embodiments described below can be employed in any combination as possible.

  In view of the above-described problems, the present inventor first tried to reduce the mass by making the inner diameter of the annular permanent magnet thinner in the radial direction by increasing the inner diameter. At that time, a space is created between the outer peripheral surface of the inner shaft member and the inner peripheral surface of the permanent magnet, which makes it difficult to center and assemble the permanent magnet. Did. However, if the spacer is larger than the axial dimension of the permanent magnet, the pair of annular yoke members is carried by the spacer, making it difficult for the permanent magnet and the annular yoke member to contact each other, increasing the magnetic resistance. As a result, there is a possibility that the generation of electromagnetic force may be reduced, and the rattling of the permanent magnet may cause abnormal noise or damage. On the other hand, if the spacer is smaller than the axial dimension of the permanent magnet, rattling of the spacer in the space on the inner peripheral surface side of the permanent magnet becomes a problem, and in addition to generation of abnormal noise, durability due to hitting and wear Degradation is also a problem. In addition to the results of these studies, it has been found that it is difficult to secure the dimensional accuracy of the permanent magnet, and that it is practically difficult to employ a spacer.

  As described above, the first aspect of the present invention, which has been completed in consideration of the new problem clarified from the result of the study by the present inventors, has an outer housing member on which a coil member is mounted and a magnet member mounted. The inner shaft member is connected to the inner shaft member by an elastic member, and an electromagnetic force generated by energizing the coil member acts on the magnet member to apply an axial driving force between the inner shaft member and the outer housing member. On the other hand, a pair of annular yoke members are superposed on both sides in the axial direction of the annular permanent magnet on the outer periphery of the inner shaft member to constitute the magnet member, and the pair of annular yoke members An electromagnetic actuator provided with a fastening member that presses the permanent magnet against the permanent magnet from both sides in the axial direction and fixes the permanent magnet to the inner shaft member. The outer magnets of the pair of annular yoke members are provided with contact portions for centering by contacting the permanent magnet and the inner peripheral surfaces of the pair of annular yoke members, respectively. The corresponding contact portion has a larger diameter than the corresponding contact portions on both axial sides for centering the pair of annular yoke members, and the pair of annular yokes are provided on both axial sides of the central contact portion. It features an electromagnetic actuator in which a gap is provided between members.

  In the electromagnetic actuator having the structure according to this aspect, since the permanent magnet is centered with respect to the inner shaft member by the large-diameter central abutting portion, the inner diameter of the permanent magnet is maintained while securing the outer diameter of the permanent magnet. It is possible to make the thickness smaller in the radial direction and to make the mass smaller by increasing.

  In addition, the central contact portion for centering the permanent magnet and the contact portions on both sides for centering the pair of annular yoke members are provided integrally with the inner shaft member, and the central contact portion is paired with the central contact portion. Since a gap is provided in the axial direction with the annular yoke member, the permanent magnet centered on the inner shaft member and the pair of annular yoke members are surely overlapped in a contact state, and the fastening member is formed. Can be fixed by Therefore, the leakage of magnetic flux between the permanent magnet and the pair of annular yoke members is suppressed, and good magnetic efficiency is ensured. Also, rattling and hitting in the axial direction between the members are prevented, and abnormal noise and damage are prevented. Can be prevented. In addition, variations in dimensions of the inner shaft member and the magnet member during manufacturing are absorbed by the gap, so that the permanent magnet and the pair of annular yoke members can be more stably assembled to the inner shaft member.

  According to a second aspect of the present invention, in the electromagnetic actuator according to the first aspect, the outer diameter of the inner shaft member is made different in the axial direction, and the axial center portion has a substantially constant outer diameter. A large-diameter portion extending in the axial direction, and both axial portions are small-diameter portions extending in the axial direction with substantially constant outer diameter dimensions, and the large-diameter portion constitutes the contact portion at the center in the axial direction. And the small diameter portion constitutes the contact portions on both sides in the axial direction.

  In the electromagnetic actuator of this aspect, the central contact portion and the contact portions on both sides in the axial direction of the inner shaft member are both formed in a substantially cylindrical outer peripheral surface shape, and the circumferential position of the inner shaft member is Irrespective of this, the centering action by the contact portion can be exerted on the permanent magnet and the annular yoke member.

  According to a third aspect of the present invention, in the electromagnetic actuator according to the first or second aspect, the gap is formed between an axially opposed surface of the contact portion at the axial center and the pair of annular yoke members. Are spread with a substantially constant gap size over the entirety of.

  In the electromagnetic actuator according to the present aspect, by setting a substantially constant gap size, it is possible to prevent the magnet member from being biased in mass. Further, by eliminating the occurrence of a large gap locally, it is also possible to suppress the entire volume of the gap to be small and efficiently secure the mass of the magnet member.

  A fourth aspect of the present invention is directed to the electromagnetic actuator according to any one of the first to third aspects, wherein both axial side surfaces of the central axial contact portion of the inner shaft member are outside the axial direction. The pair of annular yoke members have a peripheral wall shape that protrudes outward in the axial direction, and the tapered outer surface of the pair of annular yoke members protrudes toward the center in the axial direction. It is provided so as to cover the outer peripheral surface.

  In the electromagnetic actuator of this aspect, the opposed surface of the annular yoke member sandwiching the gap and the contact portion at the center in the axial direction has a tapered shape, so that the actual size of the gap in the direction perpendicular to the tapered surface is reduced. A large axial separation distance is ensured. Therefore, it is possible to set the substantial size of the gap smaller while avoiding axial contact between the annular yoke member and the contact portion at the center in the axial direction due to a dimensional error in the axial direction. In addition, when the annular yoke member is extrapolated and assembled to the inner shaft member, a guiding action by the tapered opposed surface between the annular yoke member and the contact portion at the axial center can be expected.

  A fifth aspect of the present invention is the electromagnetic actuator according to any one of the first to fourth aspects, wherein, in the inner shaft member, the contact portion at the center in the axial direction and the contact portions at both sides in the axial direction. The contact portion is integrally formed.

  In the electromagnetic actuator of this aspect, both the contact portion at the axial center and the contact portions on both sides can be integrally formed with the inner shaft member. Therefore, in the first embodiment and the like, for example, when the cylindrical contact member is fixed to the inner shaft member by press-fitting or the like, the axially central contact portion is integrally provided with the inner shaft member. In comparison, in this embodiment, the number of parts can be reduced.

  According to a sixth aspect of the present invention, in the electromagnetic actuator according to any one of the first to fifth aspects, the elastic member is disposed outside each of the pair of annular yoke members and extends in a direction perpendicular to an axis. The inner shaft member is connected to the outer housing member by the pair of leaf springs and supported so as to be relatively movable in the axial direction.

  In the electromagnetic actuator according to this aspect, the inner shaft member is supported more stably in the axial direction by supporting both sides in the axial direction of the inner shaft member with a leaf spring having a large spring ratio in the direction perpendicular to the axial direction as compared with the axial direction. Excitation displacement can be achieved.

  A seventh aspect of the present invention relates to the active vibration damping device according to the present invention, comprising an electromagnetic actuator according to any one of the first to sixth aspects, wherein a shaft in the inner shaft member is provided. An active vibration damping device is provided in which an additional mass member is provided at least at one end in the direction.

  An eighth aspect of the present invention relates to the active vibration isolator according to the present invention, which is configured to include the electromagnetic actuator according to any one of the first to sixth aspects, and has an incompressible fluid therein. In the fluid filled type vibration damping device main body provided with a fluid chamber in which the inner shaft member is attached to one end of the inner shaft member in the axial direction with respect to a vibrating member that exerts pressure fluctuation on the fluid chamber. A vibration isolator is characterized.

  According to the present invention, the inner diameter of the permanent magnet is increased by increasing the inner diameter of the permanent magnet while securing the centering accuracy with respect to the inner shaft member, without causing new problems such as leakage of magnetic flux in the magnet member, rattling between the members and hitting between the members. An electromagnetic actuator having a novel structure capable of setting a thin mass with a small thickness can be realized.

It is a longitudinal section showing an active type vibration damping device using an electromagnetic actuator as one embodiment of the present invention. FIG. 2 is an explanatory longitudinal sectional view showing an enlarged main part of an inner shaft member on which a magnet member is mounted, which constitutes the electromagnetic actuator of the active vibration damping device shown in FIG. 1. It is a longitudinal section explanatory view of an inner shaft member corresponding to Drawing 2 and showing another embodiment of the present invention. It is a longitudinal section explanatory view of an inner shaft member corresponding to Drawing 2 which shows another embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an active damping device 12 for a vehicle, which includes an electromagnetic actuator 10 according to an embodiment of the present invention. The active vibration damping device 12 has a mass member 16 disposed in a housed state with respect to an outer housing member 14 fixedly attached to an automobile body or the like as a vibration damping target member serving as a main vibration system. A mass-spring system serving as a sub-vibration system is configured by being elastically connected by a pair of leaf springs 18 and 20 as members. The stator 22 is attached to the outer housing member 14, while the mass member 16 is configured to include the inner shaft member 24 and the mover 26, and the inner shaft member 24 is The mover 26 is attached, and the mover 26 (the inner shaft member 24) is disposed inside and outside so as to be relatively displaceable in the axial direction with respect to the stator 22 (the outer housing member 14). In the following description, the vertical direction and the axial direction are the driving action direction of the electromagnetic actuator 10 and the input of vibration at which the active vibration damping device 12 exerts the active vibration damping effect, unless otherwise specified. The direction is the vertical direction in FIG.

  More specifically, the outer housing member 14 includes an outer cylindrical member 28 having a large diameter and a substantially cylindrical shape. A caulking fixing portion 29 extending downward is provided at the lower opening edge of the outer cylinder member 28, and the outer edge of the cup-shaped bottom metal fitting 30 is caulked and fixed at the caulking fixing portion 29, so that A bottom fitting 30 is attached to the lower opening of the cylindrical member 28. A thick disk-shaped lid member 32 is fitted and fixed to the upper opening of the outer cylinder member 28.

  In this way, the outer housing member 14 having the accommodation area therein is configured by covering the openings on both axial sides of the outer cylinder member 28 with the bottom fitting 30 and the lid member 32.

  The stator 22 is attached to the inner peripheral surface of the outer cylinder member 28 and is accommodated in the outer housing member 14. The stator 22 has a thick, substantially cylindrical shape as a whole, and is fixedly assembled along the inner peripheral surface at a substantially central portion in the axial direction of the outer tubular member 28.

  Specifically, the stator 22 includes coil members 34, 34 arranged in two stages, upper and lower. The coil member 34 has a structure in which an outer yoke 40 is attached to a coil 38 formed by winding a conductive metal wire around a bobbin 36 made of resin.

  The outer yoke 40 is formed of a ferromagnetic material such as iron, and overlaps the first yoke 42, which covers the coil 38 from the axial outer surface to the outer peripheral surface, so as to cover the axial inner surface of the coil 38. And a second yoke 44 provided.

  The inner peripheral edges of the first yoke 42 and the second yoke 44 superimposed on both surfaces in the axial direction of the coil 38 are axially extended at predetermined lengths from both upper and lower sides so as to cover the inner peripheral surface of the coil 38. Extends to. Then, the respective ends of the first yoke 42 and the second yoke 44 disposed close to each other from above and below in the axial direction on the inner peripheral surface of the coil 38 are opposed to each other at a predetermined distance in the axial direction. I have.

  Accordingly, a magnetic path for guiding a magnetic flux generated by energizing the coil 38 is formed around the upper and lower coils 38 by the outer yoke 40 including the first and second yokes 42 and 44. Further, a magnetic gap 46 is formed on the magnetic path between the first yoke 42 and the second yoke 44 in the axial direction, facing the inner peripheral surface of the coil 38. The magnetic gap 46 extends continuously at substantially constant intervals over the entire circumference.

  When power is supplied from the outside to the coils 38, 38, a magnetic flux is generated around the coils 38, 38, and the generated magnetic flux is guided by a magnetic path formed by the outer yokes 40, 40, and the magnetic gap 46 is formed. , 46 are formed with magnetic poles on both axial sides.

  In the present embodiment, the coil 38 of the upper coil member 34 and the coil 38 of the lower coil member 34 have winding materials wound around the bobbins 36 and 36 in opposite directions. An opposite magnetic flux is generated. The coils of the upper and lower coil members may be composed of mutually continuous wires.

  Further, in the present embodiment, the lead wires for supplying power to the winding materials of the upper and lower coil members 34, 34 extend upward from the coil members 34, 34, and are provided buried inside the lid member 32. It is connected to the power supply terminal 48. A connection connector 50 protruding outward is integrally formed on the lid member 32, and a power supply connector is connected to the connection connector 50 from the outside, so that the power supply terminal 48 in the connection connector 50 is connected to the connection connector 50. The external power supply line is made conductive.

  Further, a pair of upper and lower leaf springs 18 and 20 each having a thin disk shape are disposed on both axial sides of the stator 22. The upper and lower coil members 34, 34 located axially inward of the leaf springs 18, 20 have annular support protrusions 52 protruding axially outward from outer peripheral edges of the outer yokes 40, 40 in the axial direction. , 52 are formed. The outer peripheral edges of the leaf springs 18 and 20 are superimposed on the support projections 52 and 52, so that the leaf springs 18 and 20 on both sides are separated from the outer yokes 40 and 40 in the axially outward direction. It is arranged to extend in the direction perpendicular to the axis.

  On the axially outer side of the upper leaf spring 18, an annular plate-shaped upper holding member 54 inserted in the outer tubular member 28 is overlapped. The upper holding member 54 is engaged with a cut-and-raised piece 56 provided on the peripheral wall of the outer tubular member 28 and is positioned in the axial direction. The outer peripheral edge of the leaf spring 18 is supported by the supporting protrusion of the coil member 34. It is sandwiched between 52 and the upper holding member 54 and is fixed to the outer cylinder member 28.

  On the other hand, on the outside of the lower leaf spring 20 in the axial direction, a substantially annular plate-shaped lower holding member 60 is overlapped via a spacer ring 58 inserted in the outer tubular member 28. The lower holding member 60 is positioned and supported at a caulking fixed portion between the outer cylinder member 28 and the bottom member 30. As a result, the outer peripheral edge of the leaf spring 20 is sandwiched between the support protrusion 52 of the coil member 34 and the lower holding member 60 via the spacer ring 58 and is fixed to the outer tubular member 28. ing.

  A rubber layer 62 to be adhered is vulcanized and adhered to the surface of the lower holding member 60. The adhered rubber layer 62 seals the caulking fixed portion between the outer cylinder member 28 and the bottom fitting 30 and is interposed between the spacer ring 58 and the upper holding fitting 54 and the lower holding fitting 60. The axial dimensional error of the stator 22 sandwiched between them is absorbed.

  On the other hand, the inner shaft member 24 has a substantially rod shape extending coaxially and vertically straight on the center axis of the outer housing member 14. A mover 26 disposed in a region surrounded by the stator 22 mounted on the outer housing member 14 is fixedly mounted on the inner shaft member 24.

  The mover 26 has an armature having a structure in which an upper yoke 66 and a lower yoke 68 as a pair of annular yoke members are overlapped on the upper and lower sides of a permanent magnet 64. Further, leaf springs 18 and 20 are arranged on the outer sides of the upper and lower yokes 66 and 68 in the axial direction.

  Each of the permanent magnet 64, the upper and lower yokes 66, 68, and the upper and lower leaf springs 18, 20 has through holes 70a, 70b, 70c, 70d formed in the center. The inner shaft member 24 is inserted into the through holes 70a, 70b, 70c, 70d. In other words, on the outer periphery of the inner shaft member 24, the movable member 26 (magnet member) is configured by overlapping the annular upper and lower yokes 66 and 68 on both axial sides of the annular permanent magnet 64.

  Male screw portions are formed at both upper and lower ends of the inner shaft member 24, and the permanent magnet 64, the upper and lower yokes 66, 68, and the upper and lower leaf springs 18 are screwed by upper and lower fastening nuts 72, 72. , 20 in the direction of superposition. That is, in the present embodiment, a fastening member that fixes the mover 26 to the inner shaft member 24 is configured by the upper and lower tightening nuts 72, 72 screwed to the inner shaft member 24.

  Furthermore, the inner peripheral edges of the upper and lower leaf springs 18 and 20 are fixed to the axially outer surfaces of the upper and lower yokes 66 and 68 by the upper and lower tightening nuts 72 and 72. As a result, the mover 26 fixed to the inner shaft member 24 is elastically connected to and supported by the outer housing member 14 via the leaf springs 18 and 20 which spread in the direction perpendicular to the axis at both axial portions. I have. The upper and lower leaf springs 18 and 20 are formed with slits extending spirally in a radially intermediate portion, for example, so that the axial spring characteristics are adjusted.

  In the present embodiment, the lower male screw portion of the inner shaft member 24 extends below the mover 26. An additional spring member 74 and an additional mass member 76 are attached to a lower end portion of the inner shaft member 24 extending downward.

  The additional spring member 74 includes a connecting rubber elastic body 84 having a plurality of spoke-shaped portions extending in the radial direction, and includes a small-diameter block-shaped inner fixing bracket 80 having a center hole 78 and a large-diameter cylindrical outer fixing bracket 82. Has a structure elastically connected by

  Further, the additional mass member 76 has an annular block shape in which a mounting hole 86 is formed on a central axis, and an annular fixing piece 88 protruding inward is provided at an upper opening edge of the mounting hole 86. It has a formed structure.

  The inner fixing member 80 and the additional mass member 76 of the additional spring member 74 are externally inserted and overlapped with the lower male screw portion of the inner shaft member 24, and are fastened by being screwed to the inner shaft member 24. The inner shaft member 24 is fixed to the lower end by being tightened between the attached nut 72 and the fixed nut 90.

  A predetermined gap is provided around the additional mass member 76 with other members such as the bottom fitting 30 and the connecting rubber elastic body 84, so that the additional mass member 76 It is reciprocally movable in the axial direction integrally with the mover 26 and the like connected by the switch.

  Further, the bottom fitting 30 in which the additional spring member 74 and the additional mass member 76 are disposed has a cylindrical stopper fitting 92 extending downward from the opening. The upper end edge of the stopper fitting 92 is extended in an outer flange shape, and is fixed together with the bottom fitting 30 and the lower holding fitting 60 to the swaging fixing portion 29 of the outer tubular member 28.

  The outer fixing member 82 of the additional spring member 74 is press-fitted and fixed to the stopper member 92. Thus, the inner shaft member 24 and the outer housing member 14 are elastically connected by the connecting rubber elastic body 84 of the additional spring member 74.

  Further, at the lower end of the stopper fitting 92, a contact portion 94 protruding inward is formed. On the other hand, a plate-shaped abutment member 96 is fixed to the upper end surface of the additional mass member 76, and an opening on the outer peripheral surface is provided between the overlapping surfaces of the additional mass member 76 and the abutment member 96. A stopper groove 98 extending in the circumferential direction is formed. The contact portion 94 of the stopper fitting 92 is inserted into the stopper groove 98 with a predetermined gap.

  Thereby, when the additional mass member 76 is largely displaced in the axial direction or the direction perpendicular to the axis in the bottom fitting 30, the contact portion 94 of the stopper fitting 92 hits in the stopper groove 98, and the additional mass member 76 A stopper mechanism for limiting the amount of displacement is configured. A buffer member 100 is provided on a surface of the abutment portion 94 of the stopper fitting 92 that hits the inside of the stopper groove 98.

  Further, as shown in FIG. 2, the permanent magnet 64 constituting the mover 26 has a substantially annular shape in which both upper and lower surfaces are planes extending in a direction perpendicular to the axis, and is attached in the axial direction. By being magnetized, one magnetic pole of N / S is formed on both upper and lower surfaces. As the permanent magnet 64, a ferrite-based magnet, an alnico-based magnet, or the like can be used, but a rare-earth cobalt-based magnet is preferably used.

  The upper and lower yokes 66 and 68 are formed of a ferromagnetic material such as iron which forms a magnetic path, and in the present embodiment, the same members are used. The upper and lower yokes 66 and 68 have a flat surface corresponding to the permanent magnet 64 so that the surface to be superimposed on the permanent magnet 64 is substantially flat with respect to both end surfaces in the axial direction of the permanent magnet 64. Are superimposed almost in close contact over a wide surface.

  Further, the through holes 70a, 70b of the upper and lower yokes 66, 68 are formed in a contact inner periphery extending at a predetermined length in the axial direction with a cylindrical shape having a substantially constant inner diameter at an axially outer portion located on a side opposite to the permanent magnet 64. It has surfaces 102a and 102b. A portion of the inner peripheral surfaces of the through holes 70a and 70b closer to the permanent magnet 64 than the contact inner peripheral surfaces 102a and 102b is a circular tapered inner peripheral surface 104a whose diameter gradually increases toward the permanent magnet 64. , 104b. The maximum diameter of the tapered inner peripheral surfaces 104a and 104b is located at the opening end on the permanent magnet 64 side, and is substantially the same as the inner diameter of the permanent magnet 64.

  The upper and lower yokes 66 and 68 have an outer peripheral surface shape whose outer diameter gradually decreases toward the outside in the axial direction, that is, a peripheral wall shape in which each of the upper and lower yokes 66 and 68 protrudes outward in the axial direction. It has been. Thereby, interference with the leaf springs 18, 20 when the upper and lower yokes 66, 68 are displaced in the axial direction is avoided. In particular, in the present embodiment, the outer peripheral surface is formed in a stepped shape in which the outer diameter is gradually reduced outward in the axial direction.

  Further, of the outer peripheral surfaces of the upper and lower yokes 66, 68, the axial ends on the permanent magnet 64 side are cylindrical magnetic pole forming surfaces 106, 108 extending in the axial direction with a substantially constant outer diameter. It is desirable that the outer diameter of the magnetic pole forming surfaces 106 and 108 be slightly larger than the outer diameter of the permanent magnet 64 so that the magnetic pole can be formed efficiently.

  On the other hand, the inner shaft member 24 inserted through the permanent magnet 64 and the upper and lower yokes 66 and 68 has an outer peripheral surface whose outer diameter is different in the axial direction. In particular, the outer diameter D1 (see FIG. 2) of the central portion in the axial direction where the permanent magnet 64 is mounted is larger than the outer diameter D2 (see FIG. 2) of both axial portions where the upper and lower yokes 66 and 68 are mounted. As a result, the axially intermediate portion has a swelled shape. The inner shaft member is formed of a non-magnetic material such as an aluminum alloy or stainless steel in order to prevent a short circuit of the magnetic flux of the permanent magnet 64, and it is preferable that the inner shaft member be an integrally molded product of the above materials.

  Specifically, the inner shaft member 24 has a central portion in the axial direction in which the permanent magnet 64 is extrapolated as a large-diameter portion extending in the axial direction with an outer diameter dimension equal to or slightly smaller than the inner diameter dimension of the permanent magnet 64. The central contact portion 110 has a cylindrical shape. By contacting the inner peripheral surface of the permanent magnet 64 with the outer peripheral surface of the central contact portion 110, the permanent magnet 64 is positioned on the same central axis as the inner shaft member 24 and is centered. It has become.

  Further, in the inner shaft member 24, both side portions where the upper and lower yokes 66 and 68 are externally located on both sides in the axial direction of the center contact portion 110 are inner peripheral surface shapes of the through holes 70 a and 70 b of the upper and lower yokes 66 and 68. The outer peripheral surface shape has a deformed shape corresponding to the above.

  That is, portions of the inner shaft member 24 which are located at predetermined distances on both sides in the axial direction from the central contact portion 110 are the same as or slightly smaller than the contact inner peripheral surfaces 102a, 102b of the upper and lower yokes 66, 68. The outer contact portions 112a and 112b are small-diameter portions extending in the axial direction with a diameter dimension, and the outer peripheral surfaces of the outer contact portions 112a and 112b are cylindrical. The contact inner peripheral surfaces 102a, 102b of the upper and lower yokes 66, 68 abut against the outer peripheral surfaces of the outer contact portions 112a, 112b. 24 and are centered on the same central axis.

  In the inner shaft member 24, the outer peripheral surface between the central contact portion 110 and the outer contact portions 112a and 112b on both sides in the axial direction has a circular taper whose outer diameter gradually decreases outward in the axial direction. Outer peripheral surfaces 114a and 114b. That is, both axial side surfaces of the central contact portion 110 are tapered outer peripheral surfaces 114a and 114b whose central portions protrude outward in the axial direction.

  In the present embodiment, the tapered outer peripheral surfaces 114a and 114b of the inner shaft member 24 are formed at substantially the same inclination angles as the tapered inner peripheral surfaces 104a and 104b of the upper and lower yokes 66 and 68. Since the axial length of the central abutting portion 110 is slightly smaller than the axial length of the permanent magnet 64, the tapered outer peripheral surfaces 114a and 114b of the inner shaft member 24 are formed by the upper and lower yokes 66 and 68. Are slightly squeezed inward in the axial direction from the tapered inner peripheral surfaces 104a and 104b. That is, the upper and lower yokes 66 and 68 each having a peripheral wall shape protruding outward in the axial direction are disposed so as to cover the tapered outer peripheral surfaces 114 a and 114 b of the inner shaft member 24 from the outside. As a result, gaps 116, 116 extending over the whole are formed between the tapered outer peripheral surfaces 114a, 114b and the tapered inner peripheral surfaces 104a, 104b. In the present embodiment, annular gaps 116, 116 extending continuously over the entire circumference in the circumferential direction are formed substantially between the axially opposite surfaces of the central contact portion 110 and the axially opposed surfaces of the upper and lower yokes 66, 68. It is provided with a certain gap size.

  Therefore, although the permanent magnet 64 and the upper and lower yokes 66 and 68 are overlapped with each other in the axial direction, the upper and lower yokes 66 and 68 abut only on both axial side surfaces of the permanent magnet 64 that are the magnetic pole surfaces. Has become. Further, neither the inner circumferential surface of the permanent magnet 64 nor the upper and lower yokes 66, 68 is in axial contact with the inner shaft member 24. In the present embodiment, the inner diameters of the permanent magnet 64 and the upper and lower yokes 66 and 68 are slightly larger than the outer diameters of the central contact portion 110 and the outer contact portions 112a and 112b. The inner peripheral surfaces of the yokes 66 and 68 are centered by being brought into contact with the inner shaft member 24 in a direction perpendicular to the axis, and are positioned on the same central axis.

  The size of the gaps 116 is not particularly limited, but should be as small as possible in order to efficiently secure the mass of the mass member 16 including the inner shaft member 24 and the mover 26. Is desirable. Further, the tapered outer peripheral surfaces 114a, 114b of the inner shaft member 24 and the tapered inner peripheral surfaces 104a, 104b of the upper and lower yokes 66, 68 come into contact with each other unintentionally on the basis of a component dimensional error or the like. It is preferable to set the size so that the upper and lower yokes 66 and 68 are prevented from being separated from the magnetic pole surface, and for example, about 0.5 to 2 mm depending on the size and dimensional accuracy of the parts. It can be set to a large gap size.

  The inner shaft member 24 having the movable element 26 is magnetically poled by the upper and lower yokes 66 and 68 under the condition that the inner shaft member 24 is elastically connected to the outer housing member 14 by a pair of leaf springs 18 and 20 and an additional spring member 74 and assembled. One of N / S magnetic poles is set for the forming surfaces 106 and 108, and the magnetic poles of the stator 22 are radially opposed to the magnetic poles of the stator 22. That is, the axial thickness of the permanent magnet 64 is substantially the same as the axial distance between the upper and lower magnetic gaps 46, 46 of the stator 22, and the magnetic pole forming surfaces of the upper and lower yokes 66, 68 of the mover 26. 106 and 108 are arranged radially opposite to the magnetic gaps 46 and 46 of the stator 22 with a gap therebetween.

  As a result, when a magnetic field is generated in the upper and lower magnetic gaps 46, 46 by energizing the coils 38, 38 of the stator 22, when the magnetic field is generated in the upper and lower yokes 66 (68), the outermost peripheral portions 118 (120) of the upper and lower yokes 66 (68) are rotated. A magnetic attraction force is exerted in the direction, and an axial magnetic repulsion force is exerted on the outermost peripheral portion 120 (118) of the other yoke 68 (66). Based on the action of these magnetic forces, a driving force is applied to the mover 26 in any one of the axial directions in accordance with the direction of energization of the coils 38, 38 of the stator 22. By controlling the energization interval and energization direction to 38, an axial excitation force can be exerted on the mover 26 and thus the inner shaft member 24 at a predetermined cycle.

  In the present embodiment, the movable element 26 is held at the initial position in the axial direction with respect to the stator 22 by the elasticity of the upper and lower leaf springs 18 and 20, and the driving force by external power supply is released. In some cases, it quickly returns to the initial position.

  The electromagnetic actuator 10 having such a structure constitutes the active vibration damping device 12 by fixedly attaching the outer housing member 14 to the vibration damping target member serving as the main vibration system. . In this mounting state, the power supply to the coils 38, 38 of the stator 22 is controlled in accordance with the vibration to be damped in the axial direction, whereby the movable element 26 and the inner shaft member constituting the sub-vibration system are controlled. The desired vibration damping effect can be obtained by vibrating the 24.

  Here, in the electromagnetic actuator 10 of the present embodiment, the center contact portion 110 for centering the permanent magnet 64 is provided with the outer contact portions 112a and 112b located on both sides in the axial direction of the center contact portion 110 in the inner shaft member 24. It has a large diameter. Therefore, while the outer diameter of the permanent magnet 64 is ensured, the mass and thus the substantial required amount of the permanent magnet 64 can be reduced. Further, the entire mass of the mover 26 can be sufficiently ensured by the central contact portion 110 having a large diameter.

  In addition, gaps 116, 116 are provided in the axial direction between the central contact portion 110 for centering the permanent magnet 64 and the pair of annular yoke members (upper and lower yokes 66, 68). Since the upper and lower yokes 66, 68 and the permanent magnet 64 are prevented from separating from each other due to the abutment of the yokes 66, 68, the permanent magnet 64 and the pair of annular yoke members 66, 68 are surely overlapped in a contact state. Then, it can be fixed by fastening members (fastening nuts 72, 72).

  Therefore, leakage of the magnetic flux between the permanent magnet 64 and the pair of annular yoke members 66 and 68 is suppressed, and good magnetic efficiency is ensured. In addition, axial rattling and hitting between the members are also prevented. Sound and damage may also be prevented.

  In addition, since variations in dimensions of the inner shaft member 24 and the mover 26 (magnet member) at the time of manufacture are absorbed by the gaps 116, 116, the permanent magnet 64 and the pair of annular yoke members 66 are provided with respect to the inner shaft member 24. , 68 can be assembled more stably.

  As mentioned above, although embodiment of this invention was described in full detail, this invention is not limited by the specific description. For example, a large-diameter portion that constitutes a contact portion at the center in the axial direction for centering a permanent magnet in the inner shaft member is formed separately from a rod member extending with a substantially constant outer diameter, and is fixed by press-fitting or the like. By doing so, it is also possible to configure an inner shaft member having an outer peripheral surface having a different shape in the axial direction.

  In addition, as shown in FIG. 3, for example, in the inner shaft member 124, the large-diameter central contact portion 124 that centers the permanent magnet 64 may have a longer axial length than the permanent magnet 64. In this case, a large-diameter abutment inner periphery which is externally fitted to the center abutment portion 124 and centered at an opening end of the upper yoke 126 and the lower yoke 128 as a pair of annular yoke members on the permanent magnet 64 side. It is also possible to form the surfaces 130a, 130b.

  Furthermore, as shown in FIG. 4, for example, in the inner shaft member 132, a large-diameter central contact portion 134 for centering the permanent magnet 64 is replaced with a thick annular ring having no tapered portions on both axial sides. The permanent magnets 64 and the annular yoke members 136 and 138 are formed by forming the pair of annular yoke members into upper and lower yokes 136 and 138. It is also possible to form gaps 140, 140 that extend in the direction perpendicular to the axis between the axially superposed planes.

  Note that, in FIGS. 3 and 4 described above, for ease of understanding, members and portions having the same structure as in the above embodiment are denoted by the same reference numerals in the drawings.

  Also, the outer peripheral surface of the center contact portion or the outer contact portion for centering the permanent magnet or the annular yoke member against the inner shaft member does not need to have a cylindrical surface shape as in the above embodiment. For example, a plurality of abutting projections that partially protrude on the circumference are formed, and the distal end surfaces of the abutting projections form an abutting surface that abuts against the inner peripheral surface of the permanent magnet or the annular yoke member to perform centering. It is also possible. Further, the gap provided between the center contact portion and the annular yoke member does not need to have a substantially constant gap size throughout as in the above-described embodiment, and is partially narrow or wide. You may.

  Further, for example, the specific structure of the stator is not limited to the structure in which the coil members 34, 34 constituting the stator 22 are provided in two vertically stacked layers as in the above-described embodiment, and only one is provided. They may be provided, or three or more may be superposed in multiple stages in the axial direction. Further, the upper and lower coil members 34, 34 in the above-described embodiment employ the coils 38, 38 wound in opposite directions, but it is also possible to employ upper and lower coils wound in the same direction.

  On the other hand, with respect to the mover, various structures that generate a driving force in the axial direction by a magnetic force generated by energizing the coil member can be employed according to the structure of the stator employed. For example, it is also possible to set a plurality of magnetic poles by superposing a permanent magnet and an annular yoke member in a plurality of stages.

  Further, in the above-described embodiment, the outer housing member 14 is fixed to the vibration damping target member, so that the coil members 34, 34 constitute the stator 22, while the inner shaft member 24 is movable in the axial direction and becomes permanent. The magnet 64 constitutes the mover 26. Conversely, the stator is constituted by permanent magnets by protruding the inner shaft member in the axial direction and fixing the inner shaft member to the vibration damping target member, while the outer housing is formed. It is also possible to configure the mover with a coil member so that the member can be moved in the axial direction.

  Further, the additional mass member 76 and the additional spring member 74 adopted in the above embodiment are provided as necessary in consideration of required characteristics and the like, and are not essential in the present invention.

  Furthermore, in the above-described embodiment, the mode in which the electromagnetic actuator 10 having the structure according to the present invention is applied to the active vibration damping device 12 is exemplified. However, for example, an active vibration damping device used as an engine mount, a body mount, or the like. Application to is also possible. Specifically, for example, it can be realized by applying the electromagnetic actuator 10 as described above as an actuator in a known active vibration isolator disclosed in Japanese Patent Application Laid-Open No. 2000-337427. That is, the fluid-filled vibration isolator main body includes a fluid chamber in which an incompressible fluid is sealed, and a part of the wall of the fluid chamber is a vibration member that exerts pressure fluctuation. Therefore, in the electromagnetic actuator 10 according to the embodiment, for example, by fixing the outer housing member 14 to the mounting member of the fluid-filled type vibration damping device, the axial excitation driving force exerted on the inner shaft member 24 is provided. Can be exerted on the vibration member of the fluid-filled type vibration damping device. More specifically, for example, in the electromagnetic actuator 10 described in the embodiment, an output member provided integrally with the inner shaft member 10 and extending in the axial direction instead of the additional mass member 76 and the additional spring member 74. And the drive member is protruded outward in the axial direction to take out the driving force to the outside, whereby the vibration member of the fluid-filled type vibration damping device main body can be driven to vibrate.

  In addition, although not enumerated one by one, the present invention can be embodied in modes in which various changes, modifications, improvements, and the like are made based on the knowledge of those skilled in the art. Anything is included in the scope of the present invention unless departing from the spirit of the present invention.

10: electromagnetic actuator, 12: active vibration damping device, 14: outer housing member, 18, 20: leaf spring (elastic member), 24, 122, 132: inner shaft member, 26: mover (magnet member), 34: coil member, 64: permanent magnet, 66, 126, 136: upper yoke (annular yoke member), 68, 128, 138: lower yoke (annular yoke member), 72: tightening nut (fastening member), 76: Additional mass members, 110, 124, 134: central abutting portion (axially central abutting portion, large diameter portion), 112a, 112b: outer abutting portions (axially opposite side abutting portions, small diameter portion), 114a, 114b: tapered outer peripheral surface, 116, 140: gap

Claims (8)

An outer housing member on which the coil member is mounted and an inner shaft member on which the magnet member is mounted are connected by an elastic member, and an electromagnetic force generated by energizing the coil member acts on the magnet member so that the inner shaft member A pair of annular yoke members are superimposed on both sides of the annular permanent magnet in the axial direction on the outer periphery of the inner shaft member while an axial driving force is exerted between the inner housing member and the outer housing member. An electromagnetic actuator in which the magnet member is configured, and a fastening member for pressing the pair of annular yoke members against the permanent magnet from both sides in the axial direction and fixing the annular yoke member to the inner shaft member is provided.
A contact portion for centering by contacting the inner peripheral surface of the permanent magnet and the pair of annular yoke members is provided at an outer insertion portion of the permanent magnet and the pair of annular yoke members in the inner shaft member. The corresponding contact portion at the center in the axial direction for centering the permanent magnet is larger in diameter than the corresponding contact portions on both sides in the axial direction for centering the pair of annular yoke members. An electromagnetic actuator, wherein a gap is provided between the pair of annular yoke members on both sides in the axial direction.   The outer diameter of the inner shaft member is different in the axial direction, the central portion in the axial direction is a large diameter portion extending in the axial direction with a substantially constant outer diameter, and both axial portions are substantially constant outside. The small-diameter portion extends in the axial direction with a radial dimension, and the large-diameter portion constitutes the contact portion at the center in the axial direction, and the small-diameter portion constitutes the contact portions on both sides in the axial direction. The electromagnetic actuator according to claim 1.   3. The electromagnetic type according to claim 1, wherein the gap extends over the entire area between the axially opposed surfaces of the contact portion at the center in the axial direction and the pair of annular yoke members with a substantially constant gap size. 4. Actuator.   The two axial side surfaces of the contact portion at the center in the axial direction of the inner shaft member are tapered outer peripheral surfaces whose central portions protrude outward in the axial direction, and the pair of annular yoke members are The electromagnetic actuator according to any one of claims 1 to 3, wherein the electromagnetic actuator has a peripheral wall shape protruding outward in the direction, and is disposed so as to cover the tapered outer peripheral surface of the contact portion at the axial center. .   The electromagnetic actuator according to any one of claims 1 to 4, wherein in the inner shaft member, the contact portion at the center in the axial direction and the contact portions on both sides in the axial direction are integrally formed.   The elastic member includes a pair of leaf springs disposed outside each of the pair of annular yoke members and extending in a direction perpendicular to the axis, and the inner shaft member is formed of the outer housing by the pair of leaf springs. The electromagnetic actuator according to any one of claims 1 to 5, wherein the electromagnetic actuator is connected to a member and supported so as to be relatively movable in an axial direction.   The electromagnetic actuator according to claim 1, wherein an additional mass member is provided on at least one end in the axial direction of the inner shaft member. Active type vibration damping device.   A fluid-filled vibration damping device main body comprising the electromagnetic actuator according to any one of claims 1 to 6 and including a fluid chamber in which an incompressible fluid is sealed. An active vibration isolator, wherein one end in the axial direction of the inner shaft member is attached to a vibration member that exerts pressure fluctuations on the chamber.

Images