JP2007028713A - Linear actuator and vibration isolator using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear actuator which can achieve the improvement of durability and the downsizing and an active vibration isolator which is equipped as a vibration means. <P>SOLUTION: In a linear actuator 36 which is equipped with a moving member 48 and a stator 46 which is annular to surround it and supports the moving member so as to axially reciprocate by the excitation of a coil 44, the space between the stator 46 and the moving member 48 is filled with rubber elastic body 60 to couple both elastically. In the vibration isolator 10 which is equipped with an inner attachment member 12 attached to the rod top end 102a of a shock absorber 100, an outer attachment member 14 which is attached to the side of the car body, and a body rubber part 16 which is interposed between them, the moving member 48 of the linear actuator is connected so as to vibrate in its axial direction L to the inner attachment member 12. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a vibration type linear actuator and a vibration isolator incorporating the same as a vibration means.

  In general, a vibration type linear actuator includes a mover made of a permanent magnet or a magnetic material, and a stator having a coil, and is configured to reciprocate the mover in the axial direction by exciting the coil. ing.

Recently, in order to obtain an excellent vibration suppression effect in a vibration isolator for an automobile, a linear actuator is incorporated as a vibration means, and the vibration is canceled by applying a vibration force corresponding to the vibration to be vibration-proof. There have been proposed active vibration isolators that suppress or positively change the spring characteristics in accordance with input vibrations to reduce the dynamic springs (see Patent Documents 1 and 2 below).
JP 2001-304329 A JP 2002-195342 A

  In the linear actuators disclosed in Patent Documents 1 and 2, both ends in the axial direction of the mover have leaf springs in order to support the mover in a state where the mover is positioned in the axial direction relative to the stator. The movable element is reciprocally movable in the axial direction based on the elastic deformation of the leaf spring.

  As described above, in the conventional linear actuator, the mover and the stator are elastically coupled via the leaf springs arranged at both ends in the axial direction, and there is a gap between the mover and the stator. It was. For this reason, foreign matter may enter the gap, which may cause malfunction and impair the durability of the linear actuator, such as hindering the smooth movement of the mover.

  Further, it is necessary to secure a space for providing leaf springs at both ends in the axial direction, and accordingly, the axial dimension of the linear actuator increases.

  The present invention has been made in view of the above, and provides a linear actuator that can improve durability and can be reduced in size by reducing the axial dimension. An object of the present invention is to provide an active vibration isolator that is excellent in durability and can be downsized by being incorporated as a means.

  A linear actuator according to the present invention includes a stator including a coil and a mover that can reciprocate when the coil is excited, and the stator and the mover are interposed between the two. They are connected by an elastic body. As described above, since the mover is supported by the rubber-like elastic body interposed between the stator and the mover so as to reciprocate with respect to the stator, the conventional leaf spring is not required, and the dimension in the axial direction is reduced. As a result, the linear actuator can be reduced in size. In addition, the rubber-like elastic body interposed between the stator and the mover prevents the intrusion of foreign matters and can enhance the durability.

  In the linear actuator, the movable element has a columnar shape, and the stator has an annular shape surrounding the outer periphery of the movable element, and supports the movable element so as to be capable of reciprocating in the axial direction. It is preferable that a gap between the outer surface of the stator and the inner surface of the stator facing the outer surface is filled with the rubber-like elastic body. By thus filling the gap between the mover and the stator with a rubber-like elastic body, it is possible to eliminate the entry of foreign matter between the mover and the stator.

  In the linear actuator, an outer member is provided on the radially outer side of the movable element, and the rubber-like elastic body is integrally vulcanized and molded between the movable element and the outer member. It is preferable that the molded body is press-fitted into the inner surface of the stator. By comprising in this way, it is excellent in the assembly | attachment property of the stator and mover couple | bonded through a rubber-like elastic body.

  In the linear actuator, the mover is made of a magnetic material, and the stator has a magnetic pole portion protruding radially inward, and the magnetic pole portion has a different polarity adjacent to each other in the axial direction. At least a pair of permanent magnets are arranged, and the coil is wound around the magnetic pole portion so as to be able to generate a magnetic flux passing through the pair of permanent magnets. It is preferable that the mover is configured to reciprocate in the axial direction in combination with the magnetomotive force of each permanent magnet. By adopting such an iron core movable configuration, it is possible to eliminate the delay in the rise of the force generated by the reciprocating motion of the mover, and to enable quick and smooth drive control of the mover. Moreover, since the iron core is movable, a large output can be obtained without increasing the outer diameter.

  The vibration isolator of the present invention comprises the linear actuator as a vibration means, and in particular, a cylindrical inner mounting member, an outer mounting member surrounding the inner mounting member, the inner mounting member and the outer mounting member. A main body rubber portion that is interposed between the movable body and the movable member of the linear actuator is connected to the inner mounting member so as to vibrate in the axial direction of the inner mounting member. Preferably there is. For example, a suspension support in which the inner attachment member is attached to the upper end portion of a shock absorber rod and the outer attachment member is attached to the vehicle body side is preferable.

  In the above linear actuator, since the mover and the stator are coupled by a rubber-like elastic body interposed between them, the amplitude of the mover is generally smaller than that of the conventional type coupled by a leaf spring. It is difficult to apply to applications that require a large amplitude. On the other hand, if it is as a vibration means in the vibration isolator having the above configuration, the amplitude required for the mover is small, so that the linear actuator can be suitably incorporated, thereby improving the durability of the vibration isolator. And miniaturization in the axial direction.

  As described above, according to the present invention, the durability of the linear actuator and the vibration isolator incorporating the linear actuator can be improved, and the size can be reduced.

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

  FIG. 1 is a longitudinal sectional view of a vibration isolator 10 according to an embodiment of the present invention in use. The vibration isolator 10 includes a cylindrical inner attachment member 12 attached to the upper end 102a of the rod 102 of the shock absorber 100, an outer attachment attached to the vehicle body 104, which is a concept including a vehicle body panel, a frame, and a connecting member for these. A suspension support (upper support) includes a member 14 and a main body rubber portion 16 that is disposed between the inner mounting member 12 and the outer mounting member 14 and attenuates vibration in the axial direction L by connecting the members 14 to each other. . In FIG. 1, reference numeral 108 denotes a rubber bound stopper, reference numeral 110 denotes a dynamic damper embedded in the bound stopper, reference numeral 112 denotes a suspension coil spring, and reference numeral 114 denotes an upper end of the coil spring. Each of the spring seats is shown.

  The inner mounting member 12 includes a cylindrical metal cylindrical member 18 through which the rod upper end 102a is inserted, and a metal receiving member 20 that is connected to the upper end surface and receives the rod upper end 102a. The cylindrical member 18 includes a flange portion 22 projecting in a direction perpendicular to the axial direction on the outer peripheral surface of the intermediate portion in the axial direction, and the main rubber portion 16 is vulcanized on the outer peripheral portion of the cylindrical member 18 so that the flange portion 22 is embedded. It is glued. The receiving member 20 has a substantially cylindrical shape and has a recess 24 that opens downward, and the rod upper end 102 a is inserted and fixed in the recess 24.

  The outer mounting member 14 includes a disk-shaped metal plate member 26 that is mounted so as to close the circular mounting opening 106 provided in the vehicle body 104 from the lower surface side, and an outer peripheral portion of the plate member 26. It consists of a metal cup-shaped member 28 attached to the lower surface side. The plate member 26 is provided with a through hole 26a through which the cylindrical member 18 is inserted in the central portion thereof, and is fixedly attached to the lower peripheral edge portion of the vehicle body opening portion 106 with a bolt 30 and a nut 32 at the outer peripheral portion thereof. The cup-shaped member 28 has a container shape opening upward, and a through hole 28a through which the rod 102 is inserted is provided at the center of the bottom wall. Further, the opening edge portion of the upper end of the cup-shaped member 28 is formed as a flange portion 28 b extending outward, and the flange portion 28 b is overlapped with the outer peripheral portion of the plate member 26 and fixed by the bolt 30 and the nut 32. And, by combining the plate member 26 and the cup-shaped member 28 in this way, a housing space 34 for the main rubber part 16 is formed between them, and by housing the main rubber part 16 in the housing space 34, The inner mounting member 12 and the outer mounting member 14 are elastically coupled via a main rubber part 16.

  The vibration isolator 10 is provided with a linear actuator 36 (hereinafter referred to as “actuator”) as vibration means driven by an electromagnet. The actuator 36 is connected to the upper end portion 102a of the rod via the inner mounting member 12, and is provided so as to vibrate the rod 102 in the axial direction L thereof. In particular, in the case of the present embodiment, the actuator 36 is electrically controlled based on the vibration in the axial direction L transmitted from the tire (not shown) to the rod 102, and applies vibration to the rod 102 in accordance with the axial vibration. It is configured.

  The actuator 36 is accommodated in a housing member 38 attached to the upper surface side of the vehicle body opening 106. The housing member 38 includes a cylindrical main body portion 40 and a top plate portion 42 fixed with bolts 41 so as to close the upper end opening thereof, and the flange portion 40a to the outside of the lower end of the main body portion 40 Along with the plate member 26 and the cup-shaped member 28, the bolt 30 and the nut 32 are fixed to the vehicle body 104. Reference numeral 39 denotes a window provided in the main body 40, and is provided so as to face the diameter direction of the main body.

  Here, based on FIGS. 2-6, the structure of the actuator 36 which concerns on this embodiment is demonstrated.

  The actuator 36 includes a stator 46 including a coil 44 and a columnar movable element 48 that reciprocates when the coil 44 is excited. The stator 46 forms an annular shape that surrounds the outer periphery of the mover 48 and supports the mover 48 so as to reciprocate in the axial direction L in the hollow portion. Specifically, the stator 46 includes a yoke 50 formed by laminating a large number of annular (mainly rectangular annular) metal plates made of a magnetic metal such as an electromagnetic steel plate, and a movable element 48 sandwiched between the central portion of the yoke 50. And have magnetic pole portions 52 and 52 projecting radially inward from both sides so as to face each other. On the other hand, the mover 48 is configured as a mover iron core formed by laminating a plurality of metal plates made of the same magnetic metal as described above. In this example, the mover 48 is an intermediate portion in the axial direction of the pipe member 54 extending in the axial direction L. Is fixed to the outer peripheral surface.

  As shown in FIGS. 4 to 6, the magnetic pole portions 52, 52 of the stator 46 facing the mover 48 are adjacent to the tip, that is, the inner end, in the reciprocating direction (vertical direction) of the mover 48. A direction (left-right direction) perpendicular to the reciprocating direction so that a pair of upper and lower arc-shaped permanent magnets 56 and 58 facing the mover 48 side by side form NS alternating different poles. Are arranged so that the magnetic poles (N pole and S pole) are opposite to each other. The length from the upper end of the upper permanent magnet 56 to the lower end of the lower permanent magnet 58 is longer than the length of the mover 48 in the vertical direction (axial direction).

  The coil 44 is wound around the magnetic pole portion 52 of the stator 46, that is, the coil 44 is wound around the axis in the direction orthogonal to the reciprocating direction (the left-right direction in FIG. 2). The magnetic flux passing through the pair of permanent magnets 56 and 58 can be generated.

  In the case of the figure, a pair of permanent magnets 56, 58 are provided at the inner end portions of the two magnetic pole portions 52, 52 of the stator 46 facing each other with the mover 48 interposed therebetween, and both the magnetic pole portions 52, 52 are provided. The permanent magnets 56 and 58 are opposed to each other with the mover 48 sandwiched in a direction orthogonal to the reciprocating direction, and the magnetic poles are arranged so that the opposite magnetic poles are opposite to each other so that the opposing magnetic poles are different from each other. It is installed. Correspondingly, the coil 44 is also wound around the magnetic pole portions 52 and 52 in a state where each of the coils 44 is located outward from each permanent magnet.

  As shown in FIG. 4, the pair of coils 44 are connected to each other. 4 and 5, in this embodiment, the upper permanent magnet 56 of the pair of upper and lower permanent magnets 56, 58 on the right side has an N pole on the side facing the mover 48 and an S pole on the opposite side. The lower permanent magnet 58 has an S pole on the surface facing the mover 48 and an N pole on the opposite surface. Of the pair of left permanent magnets 56, 58, the upper permanent magnet 56 has an S pole on the surface facing the mover 48 and an N pole on the opposite side, and the lower permanent magnet 58 faces the mover 48. The surface side is the N pole and the opposite side is the S pole. 4 and 5, white arrows pointing in the left-right direction indicate the direction of the magnetomotive force of the permanent magnets 56, 58. The magnetomotive force is directed to the left side at the upper side and to the right side at the lower side.

  With the above configuration, when the coil 44 is not energized, the magnetic flux generated by the permanent magnets 56 and 58 in the left and right magnetic pole portions 52 and 52 is short-circuited through the portion of the mover 48 that faces both the magnets. Then, as shown in FIG. 5, when a positive current flows through the coil 44, a magnetomotive force in the direction of the arrow is generated in the coil 44. As a result, the direction of the magnetomotive force of the upper permanent magnet 56 and the coil 44 The direction of the magnetomotive force (the arrow in FIG. 5) is the same, the magnetic fluxes of the magnets are combined to increase the magnetomotive force, while the direction of the magnetomotive force of the lower permanent magnet 58 and the magnetomotive force of the coil 44 are The direction is reversed, and the magnetomotive force of both is canceled and weakened. As a result, an upward force (indicated by a white arrow) acts on the mover 48, and the mover 48 rises.

  As shown in FIG. 6, when a current (negative current) in the reverse direction flows through the coil 44, the direction of the magnetomotive force of the upper permanent magnet 56 and the direction of the magnetomotive force of the coil 44 are reversed. The magnetic flux is canceled and the magnetomotive force is weakened, and the direction of the magnetomotive force of the lower permanent magnet 58 and the direction of the magnetomotive force of the coil 44 are the same. Combined to increase magnetomotive force. Accordingly, a downward force (indicated by a white arrow) acts on the movable element 48, and the movable element 48 is lowered. And the direction of the electric current of the coil 44 changes alternately in the forward and reverse directions, so that the mover 48 reciprocates up and down.

  In the actuator 36 having such a configuration, in this embodiment, as shown in FIG. 2, the stator 46 and the mover 48 are coupled by a rubber-like elastic body 60 interposed therebetween (note that The rubber-like elastic body 60 is omitted in FIGS. The rubber-like elastic body 60 is provided so as to fill a gap between the outer side surface 48a of the mover 48 and the inner side surface 46a (see FIG. 3) of the stator 46 opposed thereto.

  Specifically, as shown in FIG. 3, a pair of resin outer members 62, 62 are provided on the radially outer side across the mover 48, and a rubber-like shape is provided between the mover 48 and the outer member 62. The elastic body 60 is integrally vulcanized. The vulcanized molded body 63 is press-fitted between the permanent magnets 56 and 58 provided on the inner side surface 46 a of the stator 46, specifically, the inner end surfaces of the pair of left and right magnetic pole portions 52 and 52, respectively. The mover 48 is coupled to the stator 46 via a rubber-like elastic body 60. Therefore, more precisely, the gap between the mover 48 and the permanent magnets 56 and 58 is filled with the rubber-like elastic body 60 with the outer member 62 interposed. Instead of the pair of left and right outer members 62, a cylindrical outer member surrounding the mover 48 is provided, and the rubber elastic body 60 is vulcanized between the outer member and the mover 48 over the entire circumference. May be.

  As shown in FIG. 1, the actuator 36 configured as described above is fixed to the vehicle body 104 side by fastening the stator 46 to the lower surface of the top plate portion 42 with a bolt 64 at the outer periphery thereof. The mover 48 is connected to the inner mounting member 12 via the shaft member 66 so as to be able to vibrate in the axial direction L. The shaft member 66 is inserted into the pipe member 54 and is fixed to the mover 48 by tightening the upper end portion with a nut 68. An opening through which the nut 68 can pass is provided at the center of the top plate portion 42 of the housing member 38.

  The shaft member 66 is provided in a vertical posture coaxial with the shaft center above the rod upper end portion 102 a, and the lower end portion 66 a is fixed to the receiving member 20 protruding upward from the vehicle body opening 106. Thus, it is coupled to the rod upper end 102a. In this embodiment, the shaft member 66 is connected to the rod upper end portion 102 a via the buffer member 70. The buffer member 70 is a cylindrical rubber member. The upper surface of the receiving member 20 is vulcanized and bonded to the lower surface, and the metal plate 72 is vulcanized and bonded to the upper surface. A recess 72a is provided in the metal plate 72, and the lower end 66a of the shaft member 66 is fitted and fixed in the recess 72a.

  In this way, the movable iron-core actuator 36 incorporated in the vibration isolator 10 can move the shaft member 66 up and down by passing a sinusoidal alternating current through the coil 44, and the rod upper end 102a connected thereto. A sinusoidal curve vibration can be given to. Further, by controlling the current flowing through the coil 44, the vibration state can be controlled, and the vibration applied to the rod upper end 102a can be arbitrarily controlled.

  For example, in order to reduce vehicle interior noise (such as vehicle interior noise due to tire cavity resonance), the actuator 36 generates vibration that cancels vibration in a predetermined frequency range in the axial direction of the rod 102. The drive is controlled to give Therefore, for example, an acceleration sensor that detects vibration in the axial direction of the rod 102 is provided, and a drive signal for driving and controlling the actuator 36 is generated based on a signal from the acceleration sensor, and this is input to the actuator 36. Good.

  In the present embodiment configured as described above, the stator 46 and the mover 48 of the actuator 36 are supported by the rubber-like elastic body 60 so as to be reciprocally movable. Therefore, the size in the axial direction is small, so that the actuator 36 is downsized. As a result, downsizing of the vibration isolator 10 is also achieved. Further, since the gap between the stator 46 and the mover 48 is filled with the rubber-like elastic body 60, the entry of foreign matter into this portion is prevented, so that malfunction due to the entry of foreign matter or the smooth movement of the mover 48 can be prevented. The movement is not hindered and the durability can be improved.

  The actuator 36 is a relatively compact device due to the combination of the direction of the magnetomotive force of each of the pair of permanent magnets 56 and 58 having different polarities and the magnetomotive force generated in the coil 44. However, a large output can be obtained. The actuator 36 is preferably an iron core movable type as described above, but is not limited to this in the present invention. For example, various electromagnetic types such as a moving magnet type in which a permanent magnet is provided on a mover and a solenoid type are used. It can be applied to a linear actuator. Further, the present invention can be applied not only to a type in which the mover is driven in the hollow portion of the stator, but also to a type in which the mover surrounds the outer periphery of the stator.

  Since the actuator 36 is coupled by a rubber-like elastic body 60 having a movable element 48 and a stator 46 interposed therebetween, the amplitude of the movable element 48 is generally larger than that of a conventional type that is coupled by a leaf spring. small. However, in the vibration isolator 10 having the above-described configuration, the amplitude in the axial direction L of the inner mounting member 12 is originally small due to the presence of the flange portion 22. Even it can be used effectively. From this point of view, the linear actuator is particularly preferably used for a suspension support, but is not limited to this, and can be applied to other vibration isolators such as an engine mount. Can be used for equipment.

The longitudinal cross-sectional view of the vibration isolator which concerns on one Embodiment of this invention Cross section of linear actuator Exploded sectional view of linear actuator Schematic illustration showing the action of the linear actuator Schematic explanatory diagram showing the action of the actuator when a current is passed through the coil in the positive direction Schematic explanatory diagram showing the action of the actuator when a current is passed through the coil in the reverse direction

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Vibration isolator, 12 ... Inner attachment member, 14 ... Outer attachment member, 16 ... Main body rubber part, 36 ... Linear actuator, 44 ... Coil, 46 ... Stator, 46a ... Inner side surface, 48 ... Movable member, 48a ... Outer side surface, 52 ... magnetic pole part, 56, 58 ... permanent magnet, 60 ... rubber-like elastic body, 62 ... outer member, 63 ... vulcanized molded body, 100 ... shock absorber, 102 ... rod, 102a ... upper end part, 104 ... Body, L ... axial direction

Claims (7)

  A stator provided with a coil; and a mover capable of reciprocating when the coil is excited, wherein the stator and the mover are coupled by a rubber-like elastic body interposed therebetween. Linear actuator.   The mover has a columnar shape, and the stator has an annular shape surrounding the outer periphery of the mover, and supports the mover so as to be able to reciprocate in the axial direction. The linear actuator according to claim 1, wherein a gap between the stator and the inner surface of the stator facing the side surface is filled with the rubber-like elastic body.   An outer member is provided on the radially outer side of the mover, and the rubber-like elastic body is integrally vulcanized and molded between the mover and the outer member, and the vulcanized molded body is the stator. The linear actuator according to claim 2, wherein the linear actuator is press-fitted into an inner surface of the linear actuator.   The mover is made of a magnetic material, and the stator has a magnetic pole portion protruding radially inward, and the magnetic pole portion has at least a pair of permanent magnets adjacent to each other in the axial direction and having different polarities. And the coil is wound around the magnetic pole portion so as to be able to generate a magnetic flux passing through the pair of permanent magnets, and the magnetomotive force generated by the excitation of the coils and each of the permanent magnets 4. The linear actuator according to claim 2, wherein the movable element is configured to reciprocate in the axial direction in combination with a magnetomotive force.   The vibration isolator provided with the linear actuator in any one of Claims 1-4 as a vibration means.   A cylindrical inner mounting member; an outer mounting member that surrounds the inner mounting member; and a main body rubber portion that is interposed between the inner mounting member and the outer mounting member so as to couple the two. The vibration isolator according to claim 5, wherein the movable element is connected to the inner mounting member so as to be vibrated in an axial direction of the inner mounting member.   The vibration isolator according to claim 6, wherein the inner attachment member is attached to an upper end portion of a shock absorber rod, and the outer attachment member is attached to a vehicle body side.

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