JP2010127391A - Active vibration controller and actuator used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To carry out reduction in size and weight of an active vibration damper stand A in which a top panel 5 on which equipment 1 is placed thereon is supported by a coil spring 4 as much as possible; to obtain an necessary damping characteristic without causing rise in cost. <P>SOLUTION: A bobbin 67 of a vertical linear motor unit 6 is supported to be able to roll on a floor panel 20 of a case 2 via a spherical convex part of a contact member 70 to absorb horizontal vibration by oscillation of the bobbin 67, and an O ring 65 made of high damping rubber is arranged between a pole piece 62 and the bobbin so as to generate moderate damping force. The contact member 70 formed of resin material is pressed on the case floor panel 20 by a pre-compressed coil spring 66 arranged between the pole piece 62 and the bobbin 67 with approximately constant pressing force. A horizontal linear motor unit 7 has the same structure. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an active vibration isolator that elastically supports, for example, a precision instrument that dislikes vibrations such as an electron microscope with respect to the foundation, and to which a control force that attenuates the vibrations is added by an actuator. It relates to the structure of the actuator.

  Conventionally, in this type of vibration isolator, for example, as shown in Patent Documents 1 and 2, etc., a surface plate on which a precision instrument is placed is elastically supported by a passive vibration isolation table made of a spring member and a vibration damping member. After that, a signal from a sensor for detecting the vibration state of the equipment and the surface plate (supported body) is fed back, and a control force for reducing the vibration is applied by the actuator.

  In the embodiments described in FIGS. 4, 7, and 8 of Patent Document 1, the container disposed on the base side as the vibration damping member is filled with the viscous fluid 37, and the lower end of the bar member 38 lowered from the surface plate side is filled therein. The vibration is damped by immersion and viscous resistance. 5 and 6, the damping force is obtained by the deformation of the viscoelastic member 39 passed from the surface plate to the foundation.

  As an actuator used for such an active image stabilization control, an actuator of an electromagnetic type such as a voice coil motor is required because it is required to have a small size, a relatively high output, and a very high response. Often adopted.

  As an example, Patent Document 3 discloses a configuration in which two voice coil motors are combined in an orthogonal shape so that the mover and the stator can be moved in a non-contact manner in both the front and rear and left and right directions. According to this, it is possible to output the control force in all directions in the horizontal direction and to prevent the transmission of the horizontal vibration component via the actuator.

  In addition, in the embodiment shown in FIG. 3 of the same document, the actuator (bobbin 48) and the stator (yoke 46) are connected by an elastic body (52) such as extremely flexible rubber or sponge. The vibration transmission in the up and down direction is made substantially negligible.

Furthermore, in the dynamic seismic device described in Patent Document 4, a voice coil of a loudspeaker is adopted as the electromechanical transducer 20 (actuator), and the hemisphere 24 attached to the lower end thereof is transferred to the upper surface of the base block 30. It is made to contact in a movable manner. In this way, the vibration in the lateral direction is absorbed by the swing of the voice coil, and if the amplitude is increased, the hemisphere 24 slides on the block 30 and the loudspeaker can be prevented from being damaged.
Japanese Patent Laid-Open No. 08-128498 JP 2007-78122 A Japanese Patent Application Laid-Open No. 08-074928 Japanese Examined Patent Publication No. 06-017705

  By the way, in the case of a vibration isolator on which a relatively small precision device is placed, there is a demand for itself to be as small and light as possible, and it is not preferable to provide a damping member separately as in the former conventional example. . In particular, as disclosed in FIG. 4 and the like of Patent Document 1, a structure that obtains attenuation by the viscous resistance force of a liquid is not suitable for weight reduction and becomes a relatively large structure, which is likely to be expensive. .

  In view of such a point, the present invention provides a damping member integrally provided in the actuator of the active vibration isolator to meet the demand for downsizing and weight reduction, and requires a simple structure without increasing the cost. Attenuation characteristics are obtained.

  That is, in the present invention, like the actuator of Patent Document 4, the movable element is brought into contact with any member on the supported side or the base side via a spherical convex portion so as to be able to roll, and the swinging thereof A damping member made of high damping rubber is disposed between the stator and the stator so as to absorb vibrations and generate a damping force with the swing of the mover.

  Specifically, the invention of claim 1 is an actuator of an active vibration isolator in which a control force for reducing the vibration is added to a supported body elastically supported with respect to a foundation, A stator that is fixed to any one member on the foundation side, and a movable element that reciprocates in a predetermined direction with respect to the stator and applies a control force to the other member on the supported body side or the foundation side; It has.

  Then, the movable element is brought into contact with the contact surface of the other member via a spherical convex portion provided on the movable element so as to be able to roll, and the control is performed in a non-contact state with respect to the stator. Hold it so that it swings in any direction perpendicular to the line of action of the force, and then provide a damping member of high damping rubber between it and the stator to dampen the swing of the mover. ing.

  With the above-described configuration, first, the actuator is controlled in accordance with the vibration of the supported body, and a control force that attenuates the vibration is generated, so that the vibration of the supported body is effective in the direction of the line of action of the control force. Can be suppressed. On the other hand, the vibration component in the direction perpendicular to the line of action of the control force is absorbed by the swing of the mover of the actuator, and this swing is attenuated by the damping member of the high damping rubber, Convergence of vibration is accelerated.

  In other words, the structure for attenuating the vibration of the supported body is integrated with the actuator, which is advantageous in reducing the size of the vibration isolator, and a damping member is provided between the movable element and the stator of the actuator. Since it is an extremely simple structure, it is advantageous for weight reduction and there is almost no increase in cost.

  In addition, an elastic body such as an O-ring may be arranged between the mover and the stator so as to be relatively movable in the direction of the action line of the control force. Can be used as a damping member. When an O-ring or the like is used in this manner, this elastically deforms as the mover swings, so that the damping force is applied in the direction perpendicular to the control force action line (hereinafter also referred to as the orthogonal direction) as described above. At the same time, an elastic force that opposes the displacement due to the vibration is also generated.

  When the amplitude of the supported body is increased and the displacement in the orthogonal direction is larger than a predetermined value, the movable member starts to slide on the surface where the spherical convex portion comes into contact. If the force or damping force changes suddenly, the anti-vibration performance may be impaired. Therefore, it is desirable that a certain amount of sliding friction force is generated between the spherical convex portion and the contact surface.

  Therefore, the spherical convex portion is formed of a resin material, and is elastically deformed when pressed against the contact surface so as to ensure a certain contact area. In this way, the frictional force generated between the two is stabilized, and the elastic force and damping force received by the mover do not change suddenly even when the spherical convex portion slides on the contact surface as described above. Therefore, it is possible to stably give attenuation to the vibration in the direction orthogonal to the action line of the control force in the actuator.

  More preferably, a spring member is disposed between the stator and the mover in a precompressed state so as to press the mover in the direction of the line of action of the control force. Then, by adjusting the precompression amount of the spring member, the frictional force between the spherical convex portion and the contact surface of the mover can be set to a desired magnitude.

  In other words, the present invention is directed to an active vibration isolator using the actuator as described above, and the actuator is arranged between the supported body and the foundation so that the line of action of the control force faces the vertical direction. In order to maintain the height of the supported body substantially constant in accordance with the elastic deformation of each of the elastic struts, and a plurality of elastic struts that support the supported body from the bottom so as to float from the foundation. And a height adjusting mechanism to be adjusted (claim 4).

  According to this active vibration isolator, a vertical control force can be generated by the actuator to effectively suppress the vertical vibration of the supported body, and the horizontal vibration can be achieved by the swing of the movable element of the actuator. Can be absorbed and attenuated.

  Also, for example, even if the weight of the supported body changes due to a change in the equipment to be mounted and the elastic deformation amount of the elastic column that receives this changes, the height is maintained substantially constant by adjusting the height adjusting mechanism. Therefore, the pre-compression amount of the spring member disposed between the stator and the mover in the actuator can be kept substantially constant. Therefore, the operation of the invention of claim 3 can be obtained regardless of the change in the weight of the support.

  Furthermore, another actuator is arranged in the middle between the supported body and the foundation, and a control force is applied in the horizontal direction between the hanging wall section hanging from the supported body side and the standing wall section standing on the foundation side. If it is made to act (Claim 5), the horizontal vibration of the supported body can be more effectively suppressed by the operation of the horizontal actuator.

  In addition, the vibration in the vertical direction is appropriately attenuated by the swing of the mover in the horizontal actuator, and the vibration of the supported body is more effectively reduced in all the vertical and horizontal directions. Can do.

  As described above, according to the active vibration isolator according to the present invention, the mover of the actuator that generates the control force rolls to the member on the supported side or the base side via the spherical convex portion. The movable member is supported and absorbs vibration in the direction perpendicular to the line of action of the control force by swinging the movable element, and is also vibrated by a damping member made of high damping rubber disposed between the movable element and the stator. As compared with the conventional example in which a vibration damping member is separately provided, it is advantageous for reducing the size and weight of the vibration isolator, and there is little fear of increasing the cost with a very simple structure.

  In particular, if an elastic body such as an O-ring disposed between the mover and the stator is used as the damping member, it is more preferable in terms of cost. In this case, if the spherical convex portion of the mover is further formed of a resin material, a damping force can be stably obtained by the frictional force even when it slides on the contact surface.

  Furthermore, if a spring member is disposed in a pre-compressed state between the stator and the mover and the mover is pressed against the surface against which the mover contacts with a required force, as described above. The above effect can be further enhanced by setting the desired magnitude of the sliding friction force generated between the spherical convex portion of the mover and the contact surface.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the following description of preferable embodiment is only an illustration essentially, and is not intending restrict | limiting this invention, its application thing, or its use.

(Configuration of vibration isolator)
FIG. 1 shows a schematic configuration of a precision vibration isolation table A which is an embodiment of the vibration isolator according to the present invention. The vibration isolation table A is mounted with a device 1 (indicated by a virtual line) that dislikes vibration, such as a precision measurement device such as an electron microscope, an atomic force microscope, a semiconductor-related test device, or an inspection device. It is intended for relatively small equipment used mainly for testing and research, and it is assumed that the equipment will be replaced for the convenience of the user.

  The vibration isolation table A includes a case 2 installed on the upper surface of a dedicated table or table (not shown), and coils disposed at four corners of the case 2 via height adjustment mechanisms 3, 3,. .. (Elastic struts) and the four springs are supported by the springs 4, 4,... And float from the case 2, while the top plate on which the device 1 is placed 5 (surface plate).

  In this example, the case 2 is cast from an aluminum alloy, and a substantially rectangular floor plate 20 (a member on the base side) and a peripheral wall 21 around its outer peripheral edge are integrally formed. For example, compared to a press-formed product of an iron plate, for example. In addition to being highly rigid, it can provide relatively large damping as an aluminum alloy. Further, as shown by broken lines in FIG. 1, ribs 20a,... Are formed at important points on the floor plate 20 of the case 2 to enhance the overall rigidity.

  As shown in an enlarged view in FIG. 2, the height adjusting mechanism 3 is screwed onto the screw shaft 30, which is rotatably disposed so as to extend vertically upward from the floor plate 20 of the case 2. A spring seat 31 that holds the lower end of the coil spring 4 and a driven gear 32 that is rotatably and integrally fixed to the screw shaft 30 below the spring seat 31 are provided. The intermediate gear 33 (see FIG. 1) that meshes with the driven gear 32 is rotated by a pinion fixed to the rotating shaft of the electric motor 34, whereby the screw shaft 30 rotates and the spring seat 31 moves up and down. It comes to move.

  Thus, the coil springs 4 arranged through the height adjusting mechanism 3 are of unequal pitches in this example, and the spring constant increases in proportion to the increase in load due to the weight of the device 1. It has characteristics. For this reason, even if the device 1 is changed as described above and the weight of the supported body is changed, the natural frequency of the spring system is kept substantially constant. A high vibration isolation effect can be obtained by active control.

  Further, the top plate 5 elastically supported by the four coil springs 4, 4,... Is vertically and horizontally displaced relative to the case 2 by several millimeters in the vertical and horizontal directions, respectively. Four linear motor units 6, ..., 7, ... (actuators) are arranged. The four linear motor units 6 for vertical use are arranged upright close to a portion where the ribs 20a of the case 2 intersect with each other, and the vertical linear motor units 6 in the vertical direction with respect to the top plate 5 from the floor plate 20 of the case 2 are arranged. Add control power.

  On the other hand, the four horizontal linear motor units 7,... Form two pairs, one facing the longitudinal direction of the top plate 5 and the other facing the width direction, around the center of gravity of the top plate 5. It is arranged so that a couple in the opposite direction is generated. As shown in an enlarged view in FIG. 3, the horizontal linear motor unit 7 is horizontally disposed between a hanging wall portion 5 a hanging from the lower surface of the top plate 5 and a standing wall portion 20 b erected on the floor plate 20 a of the case 2. It is placed on its side so that the control force acts in the direction.

  The vertical and horizontal linear motor units 6 and 7 are the same, and an acceleration sensor 8 is integrally provided as shown for the vertical linear motor unit 6 in FIG. A signal indicating the relative acceleration of the top plate 5 (vibration state of the top plate 5) is output from the acceleration sensor 8, and a control signal is output from the controller 10 receiving this signal to the linear motor unit 6. A control force that reduces the vibration is applied to the device 1. That is, as an example, active vibration isolation control of acceleration feedback is performed.

  Note that a signal from a sensor 9 (shown only in FIG. 1) for detecting the height of the top plate 5 is also input to the controller 10, and the controller 10 that receives this signal controls the electric motor 34 of the height adjusting mechanism 3. By controlling, the lower end position is adjusted according to the elastic deformation of the coil spring 4, and the height of the top plate 5 is kept substantially constant.

(Configuration of linear motor unit)
Next, the structure of the linear motor unit 6 will be described in detail with reference to FIG. This figure is a cross-sectional view of the vertical linear motor unit 6, but as described above, the horizontal one has the same structure except for the case 2 and the top plate 5.

  As shown in the figure, the vertical linear motor unit 6 is integrated with an acceleration sensor 8 arranged at the upper portion and fixed to the top plate 5 of the vibration isolation table A, and a non-contact side. It is assembled into a movable side (movable element) assembled in a contact state and moved in the vertical direction by electromagnetic force. The fixed side also serves as a housing and is formed in a bottomed cylindrical shape. In the drawing, the iron yoke 60 is turned upside down and opened downward, and is concentrically accommodated in the cylindrical wall portion 60a. A disk-shaped magnet 61 and a pole piece 62 to be bolted.

  The bottom portion 60b of the yoke 60 is formed with, for example, four screw holes at intervals in the circumferential direction, and an annular bracket 64 (on the side of the supported body) by bolts 63,. Member). The bracket 64 engages with a flange portion 8a projecting from the outer periphery of the cylindrical case of the acceleration sensor 8 to fix the acceleration sensor 8 to the yoke 60, and from above with a separate bolt (not shown). Fastened to the plate 5.

  The magnet 61 and the pole piece 62 have a relatively thick disk shape having the same diameter and the same thickness. In the example shown in the figure, a diameter-reduced portion is formed in a step shape so that a circumferential groove is formed between the pole piece 62 and the magnet 61, and the circumferential groove is made of rubber made of high damping rubber. An O-ring 65 (attenuating member) is fitted. The O-ring 65 is mainly composed of, for example, fluorine rubber, nitrile rubber, butyl rubber, polynorbornene rubber, epoxidized natural rubber, silicon rubber, etc., and has a hardness after vulcanization of 60 to 80 degrees and a loss factor of about 0. It is preferably about 4 to 1.0.

  Further, the pole piece 62 is formed with a concave section 62a having a circular cross section so as to open at the center of the lower surface thereof, and a coil spring 66 for urging the bobbin 67 downward is inserted into the recess 62a as described below. Has been.

  That is, the movable side of the linear motor includes a bottomed cylindrical bobbin 67 made of a resin material and a coil 68 formed by winding an electric wire around the cylindrical wall portion 67a. The bobbin 67 opens upward in the drawing. The yoke 60 is arranged so that its axis (axis Z) coincides, and its cylindrical wall portion 67a surrounds the magnet 61 and the pole piece 62 in a non-contact state, while the cylindrical wall portion 60a of the yoke 60 has Surrounded in a non-contact state.

  As described above, the outer periphery of the O-ring 65 fitted in the circumferential groove of the pole piece 62 comes into contact with the inner peripheral surface of the cylindrical wall portion 67a of the bobbin 67 arranged coaxially. 62 and the outer peripheral surface of the magnet 61 and the inner peripheral surface of the cylindrical wall portion 67a of the bobbin 67 are kept at a predetermined size, and the outer peripheral surface of the cylindrical wall portion 67a of the bobbin 67 and the cylindrical wall portion 60a of the yoke 60 are maintained. The distance from the inner peripheral surface is also kept at a predetermined size.

  Further, the bottom wall portion 67b of the bobbin 67 has a relatively thick disk shape in the example shown in the figure, and a rubber diaphragm is formed between the portion near the outer periphery of the lower surface and the lower end surface of the cylindrical wall portion 60a of the yoke 60. It is connected by 69. The diaphragm 69 is formed of a very soft rubber, and the entire circumference of the bobbin 67 and the bottom wall portions 67b and 60a of the yoke 60 is greatly deflected, thereby allowing relative movement of the bobbin 67 in the axis Z direction. The both sides of the bobbin 67 are bent in opposite phases (see FIG. 6), thereby allowing the bobbin 67 to swing.

  Further, the lower end of a coil spring 66 whose upper portion is fitted in the recess 62 a of the pole piece 62 is in contact with the upper surface of the bottom wall portion 67 b of the bobbin 67. The coil spring 66 is pre-compressed so as to press the bobbin 67 downward even when no external force is applied, so that not only the top plate 5 can be pushed up but also a control force can be generated in the direction in which the top plate 5 is pulled down. The amount of pre-compression is determined by the distance between the lower surface of the pole piece 62 and the upper surface of the bottom wall portion 67b of the bobbin 67. In this embodiment, the height of the top plate 5 is made substantially constant by the height adjusting mechanism 3 as described above. As a result, the pre-compression amount is kept substantially constant.

  In other words, the bobbin 67 on the movable side of the linear motor unit 6 is held in a non-contact state by the O-ring 65 and the diaphragm 69 with respect to the yoke 60 on the fixed side, and reciprocates in the axis Z direction by electromagnetic force. The control force in the vertical direction is output between the case 2 floor plate 20 and the top plate 5 and is held so as to be swingable in an arbitrary direction perpendicular to the action line (vertical axis Z) of the control force, that is, in the horizontal direction. Has been.

  In addition, a circular pedestal portion 67c is formed on the bottom wall portion 67b of the bobbin 67 that reciprocates in the direction of the axis Z so as to bulge downward at a portion on the inner peripheral side thereof. A contact member 70 for contacting the upper surface 20a (contact surface) of the floor plate 20 of the case 2 to transmit the control force is fitted and inserted into the recess 67d having a circular cross section that is opened substantially at the center of the lower surface. Yes.

  The abutting member 70 is made of, for example, a resin material such as MC nylon in a cylindrical shape, and the tip (lower end in the figure) is a spherical convex part, while the base end (upper end in the figure) In the example shown in the figure, the outer diameter of the collar is substantially the same as the inner diameter of the recess 67d. A pressing plate 71 is superimposed on the lower surface of the pedestal portion 67c, and a round hole having substantially the same diameter as the outer diameter of the abutting member 70 excluding the flange portion is formed on the lower surface of the pedestal portion 67c. The abutment member 70 is pressed down to prevent the contact member 70 from coming off.

  In the illustrated example, a coil spring 72 is also disposed in the recess 67d. The coil spring 72 has a considerably higher spring constant than the coil spring 66 that biases the bobbin 67 downward. Therefore, the coil spring 72 normally does not bend and is not compressed until the pole piece 62 and the bobbin 67 come into contact with each other due to excessive external force. This is to prevent them from taking damage.

  Then, since the bobbin 67 is supported by the upper surface (contact surface) of the floor plate 20 of the case 2 via the contact member 70 at the lower end portion thereof so as to be able to roll, in the vertical linear motor unit 6. As described later, when the yoke 60 and the bobbin 67 are displaced relative to each other in the horizontal direction due to horizontal vibration, the bobbin 67 is swung by the abutting member 70 rolling on the floor plate 20, and the displacement (See FIG. 6).

  Along with the swing, the O-ring 65 is elastically deformed between the inner peripheral surface of the cylindrical wall portion 67 a of the bobbin 67 and the outer peripheral surface of the pole piece 62, and an elastic force and a damping force that suppress the swing of the bobbin 67. appear. When the displacement is further increased, it starts to slide on the case floor plate 20 with which the contact member 70 contacts, and a damping force is generated by sliding friction.

  As shown in FIG. 5, the linear motor unit 6 having the above-described structure is assembled by first combining a magnet 61 and a pole piece 62 with an O-ring 65 interposed therebetween, and then assembling this on a yoke 60 to a bolt. Fasten with 73. On the other hand, after the coil spring 72 is inserted into the recess 67d of the bobbin 67, the contact member 70 is fitted and the presser plate 71 is screwed.

  Then, the coil spring 66 is inserted into the recess 62a of the pole piece 62, the bobbin 67 is assembled to the yoke 60 so as to sandwich the coil spring 66, and the diaphragm 69 is attached and screwed so as to close the opening of the yoke 60. Finally, when an acceleration sensor 8 (not shown) is assembled, the linear motor unit 6 is completed as shown in FIG.

(Operation of linear motor unit)
Next, the operation of the linear motor units 6 and 7 in the vibration isolation table A of this embodiment will be described with reference to FIG. 6 in addition to FIG. First, the vertical linear motor unit 6 is controlled by the controller 10 based on the signal from the acceleration sensor 8 as described above, and a control force is applied to the top plate 5 and the device 1 so as to reduce the vertical vibration. To do. Thereby, the vibration of the device 1 is effectively suppressed in the vertical direction.

  Similarly, the horizontal linear motor unit 7 is also controlled by the controller 10 and applies a control force to the top plate 5 and the device 1 so as to reduce the horizontal vibration. Thereby, the vibration of the device 1 is effectively suppressed also in the horizontal direction.

  In the vertical linear motor unit 6 with respect to the vibration in the horizontal direction, the vibration is absorbed by the swing of the bobbin 67 and appropriate attenuation is applied. That is, as schematically shown in FIG. 6, when the fixed side such as the yoke 60 is displaced to the left side of the drawing together with the device 1 and the top plate 5, the bobbin 67 on the movable side rolls the contact member 70 at the lower end thereof. To absorb the relative displacement with the yoke 60 and the like.

  At this time, on the right side of the figure, the interval between the cylindrical wall portion 67a of the bobbin 67 and the pole piece 62 is narrowed, and the O-ring 65 is compressed to generate an elastic force (compression reaction force). A moderate damping force is generated by the loss. Therefore, in the vertical linear motor unit 6, the horizontal vibration can be appropriately attenuated and the convergence thereof can be accelerated.

  Further, when the relative displacement becomes larger than a predetermined value due to relatively large vibration, the tip (spherical convex portion) of the contact member 70 slides out on the case floor plate 20, which is made of resin material. And is pressed against the case floor plate 20 by the coil spring 66 in a pre-compressed state with a substantially constant pressing force, so that the tip end of the contact member 70 is elastically deformed to a certain contact area. As a result, an appropriate sliding frictional force is stably generated.

  Therefore, even when the contact member 70 slides on the case floor plate 20 as described above, the force acting in the horizontal direction between the bobbin 67 and the yoke 60 does not change suddenly, and the vibration in the horizontal direction is not affected. Attenuation can be stably applied. Similarly, in the horizontal linear motor unit 7, vertical vibrations are absorbed by the bobbin swing, and moderate attenuation is given to the vibrations so that the convergence thereof is accelerated.

  Therefore, according to the linear motor units 6 and 7 of the vibration isolation table A according to this embodiment, the movable-side bobbin 67 is placed on either the supported side or the base side via the spherical convex portion of the contact member 70. An O-ring 65 elastically deformed between the fixed piece and the pole piece 62 while absorbing the vibration in the direction perpendicular to the line of action of the control force by swinging the member so that it can roll. A moderate damping force can be obtained. That is, using the damping member also as the O-ring 65 of the linear motor units 6 and 7 is advantageous for reducing the size and weight of the vibration isolation table A, and does not cause an increase in cost.

  Further, since a relatively large vibration can be attenuated by a frictional force when the contact member 70 slides on the contact surface, the magnitude of the force does not change suddenly even when it starts to slide. It is possible to stably provide damping to vibration.

  The configuration of the vibration isolator of the present invention is not limited to the vibration isolation table A of the above embodiment. For example, in the linear motor units 6 and 7, not only the O-ring 65 but also the diaphragm 69 can be formed of high damping rubber, but they are not made high damping rubber, and a damping member of high damping rubber is provided separately from them. May be provided.

  The structures of the linear motor units 6 and 7 described above are merely examples, and the shapes of the yoke 60 and the bobbin 67 may be different. In contrast to the above example, the yoke 60 is a movable side, and the bobbin 67 may be the fixed side.

  Further, the number of vertical linear motor units 6, 6,... In the vibration isolation table A may be three or more, and similarly, the coil spring 4 that supports the top plate 5 may be three or more. Instead of the coil spring 4, for example, a rubber elastic body or a gas spring can be used. However, the metal coil spring 4 does not require a pressure source such as a gas spring and has relatively little variation in characteristics. preferable.

  Various configurations can also be applied to the height adjusting mechanism 3, and the arrangement thereof is not limited to the above embodiment.

  Further, as a method of active vibration isolation control by the operation of the linear motor units 6 and 7, not only the feedback control as in the above embodiment, the vibration transmitted to the top plate 5 is estimated based on the vibration state of the case 2, So-called feed-forward control that generates a control force that cancels this vibration, and so-called vibration-suppressing feed-forward control that generates a control force that predicts the vibration associated with the operation of the device 1 and cancels it are also possible. .

  The present invention is advantageous in reducing the size and weight of an active type vibration isolator that suppresses vibrations of precision equipment, and does not cause an increase in cost. It is very suitable for.

It is a figure which shows schematic structure of the precision vibration isolator which concerns on embodiment of this invention. It is an enlarged view which shows schematic structure of a coil spring and a height adjustment mechanism. It is an enlarged view which shows arrangement | positioning of the linear motor unit for horizontal. It is an enlarged view which shows the structure of a linear motor unit. It is an exploded view which shows the assembly | attachment procedure of a linear motor. It is explanatory drawing which shows typically rocking | fluctuation of the bobbin by the vibration of a horizontal direction.

Explanation of symbols

A Precision vibration isolation table (anti-vibration device)
1 Precision equipment (supported body)
2 Case 20 Floor board (foundation side member)
3 Height adjustment mechanism 4 Coil spring (elastic strut)
5 Top plate (plate: supported body)
6,7 Linear motor unit (actuator)
60 York (stator)
61 Magnet (stator)
62 Pole piece (stator)
64 Bracket (member on the supported body side)
65 O-ring (damping member)
66 Coil spring (spring member)
67 Bobbins
68 Coil (mover)
69 Diaphragm 70 Contact member (spherical convex part)

Claims (5)

An active vibration isolator actuator that adds a control force to reduce the vibration to a supported body elastically supported with respect to the foundation,
A stator that is fixed to one member on the supported body side or the foundation side, and reciprocates in a predetermined direction with respect to the stator, and applies control force to the other member on the supported body side or the foundation side And a mover that
The movable element is slidably contacted with the contact surface of the other member via a spherical convex portion provided on the movable element, and the control force is not contacted with the stator. It is held so that it can swing in the direction perpendicular to the action line,
An actuator for an active vibration isolator, wherein a damping member of high damping rubber is provided between the mover and the stator so as to attenuate the swing of the mover. The actuator of claim 1.
The damping member is disposed between the stator and the stator so as to be elastically deformed as the mover swings.
An actuator for an active vibration isolator in which a spherical convex portion of the mover is formed of a resin material. The actuator of claim 2,
An actuator for an active vibration isolator, in which a spring member is disposed between the stator and the mover in a precompressed state so as to press the mover in the direction of the line of action of the control force. An active vibration isolator using the actuator according to claim 3,
A plurality of elastic struts that support the supported body from below so as to float from the foundation;
A height adjusting mechanism that is adjusted so as to maintain the height of the supported body substantially constant according to the elastic deformation of the elastic column;
The active vibration isolator, wherein the actuator is disposed so that a line of action of a control force faces a vertical direction between the supported body and the foundation. The active vibration isolator according to claim 4,
An actuator is disposed between the hanging wall portion hanging from the supported body side and the standing wall portion standing on the foundation side so that the control force is applied in the horizontal direction. Active vibration isolator.

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