JP2016178707A - Linear actuator and vibration isolation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress variation in thrust in driving of a linear actuator and enables the thrust to be controlled with high accuracy with simple constitution.SOLUTION: A linear actuator 100 has: a motor 102; a movable part 104 having a first magnet 111 and an output shaft 116; and a rotary part 106 which has a second magnet 112 and a third magnet 113 arranged opposite to each other on both sides of the first magnet 111 in an axial direction A of the output shaft 116 with gaps left respectively and coupled by a nonmagnetic body 120, and is driven by the motor 102 to rotate, and supports the movable part 104 movably in the axial direction A; and a spring member 108 (restriction part) which limits a movement range of the movable part 104, opposite surfaces of the first magnet 111, second magnet 112 and third magnet 113 having alternately different magnetic poles in a rotating direction R of the rotary part 106, and the magnetic poles of the opposite surfaces of the second magnet 112 and third magnet 113 being in phase.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a linear actuator and a vibration isolator.

  A motor-driven linear oscillator that uses the attractive force and repulsive force of a pair of permanent magnets is disclosed (see Patent Document 1).

JP 2005-348469 A

  However, as in the above-described conventional example, when the vibration is generated or the linear oscillator is driven, the distance between the permanent magnets is changed, so that it is considered that the thrust fluctuation increases.

  In view of the above facts, an object of the present invention is to suppress a fluctuation in thrust during driving of a linear actuator with a simple configuration and to control the thrust with high accuracy.

  The invention of claim 1 (linear actuator) includes a motor, a movable part in which the first magnet and the output shaft are combined, and one side and the other side of the first magnet in the axial direction of the output shaft. Each of the first and second magnets is disposed opposite to each other with a gap, and has a second magnet and a third magnet connected and integrated by a non-magnetic material. A rotating portion that is rotationally driven as a center and supports the movable portion so as to be movable in the axial direction; and the movable portion of the movable portion so that the first magnet is not attracted to the second magnet or the third magnet. A restricting portion that restricts a moving range, and the opposing surfaces of the first magnet, the second magnet, and the third magnet have magnetic poles that are alternately different in the rotation direction of the rotating portion. The second magnet and the third magnet. , The magnetic poles of the opposing surfaces is the same phase in the rotational direction, the same magnetic poles are opposed in the axial direction.

  In this linear actuator, in the second magnet and the third magnet, the magnetic poles of the opposing surfaces are in the same phase in the rotation direction, and the same magnetic poles are opposed in the axial direction, so the first magnet and the second magnet When an attractive force is generated between the magnets, a repulsive force is generated between the first magnet and the third magnet. The directions of the attractive force and the repulsive force are the same direction, and the movable part moves in that direction. At this time, since the movement range of the first magnet is limited by the limiting unit, the first magnet is not attracted to the second magnet.

  When the rotating part is rotated by the motor and the magnetic poles of the second magnet and the third magnet facing the first magnet are reversed, a repulsive force is generated between the first magnet and the second magnet, An attractive force is generated between the first magnet and the third magnet. The directions of the attractive force and the repulsive force are opposite to those before the rotation of the rotating part, and the movable part moves in that direction. At this time, since the movement range of the first magnet is limited by the limiting unit, the first magnet is not attracted to the third magnet. In the movable part, since the first magnet is combined with the output shaft, positive and negative axial forces (thrust) are alternately generated in the movable part when the rotating part is continuously rotated by the motor. Thereby, a movable part vibrates.

  In the rotating part, the second magnet and the third magnet are connected and integrated by a non-magnetic material, so that the axial direction between the second magnet and the third magnet when the rotating part rotates The distance does not change. Therefore, even if the movable portion moves and the axial position of the first magnet changes, the axial distance between the second magnet and the first magnet, the first magnet, and the third magnet The sum total with the axial distance between them does not change either. As a result, even if the axial position of the movable part changes, fluctuations in the total magnetic force passing through the first magnet are suppressed. For this reason, the fluctuation | variation of the thrust of the movable part at the time of the drive of a linear actuator can be suppressed, and this thrust can be controlled with high precision.

  According to a second aspect of the present invention, in the linear actuator according to the first aspect of the present invention, the linear actuator is provided on a side opposite to the motor side in the axial direction of the rotating portion, the output shaft is inserted, and does not rotate when the motor operates A fixing member fixed to a part, and one end of the restricting portion is fixed to the output shaft, the other end is fixed to the fixing member, and the movement of the movable portion in the axial direction and the rotation direction is performed. The spring members each generate a repulsive force.

  In this linear actuator, the spring member as the limiting portion generates a repulsive force with respect to the movement of the movable portion in the axial direction and the rotational direction. Therefore, when the rotating part is rotated by the motor, the first magnet of the movable part is not attracted to the second magnet or the third magnet, and the movable part is prevented from being supplied to the rotating part. . For this reason, the thrust of a movable part can be generated efficiently and stably.

  According to a third aspect of the present invention (anti-vibration device), a first attachment member connected to either the vibration generating portion or the vibration receiving portion, and a first attachment member connected to either the vibration generating portion or the vibration receiving portion. And an elastic body that couples the first mounting member and the second mounting member, deforms in response to vibration input from the vibration generating unit, and encloses a liquid, and the elastic body 3. A liquid chamber that expands and contracts due to deformation of the liquid, a movable plate having one surface facing the liquid chamber, and the other surface of the movable plate, wherein the movable plate is vibrated. A linear actuator as described.

  When the first mounting member of the vibration isolator is connected to, for example, an automobile engine that is a vibration generation source, and the second mounting member is connected to, for example, the vehicle body that is a vibration receiving portion, the automobile engine has the first mounting member, elastic It is supported by the vehicle body via the body and the second attachment member. At this time, the vibration of the automobile engine is absorbed by the resistance based on the internal friction of the elastic body.

  Here, in this vibration isolator, since the elastic body and the movable plate face the liquid chamber, the rigidity (area, thickness, hardness, etc.) of the elastic body and the movable plate should be set appropriately. Thus, the elastic body and the movable plate can be vibrated at the time of vibration input in the frequency region that becomes idle vibration and booming noise, thereby suppressing an increase in the dynamic spring constant of the vibration isolator. In other words, in this vibration isolator, the passive performance at the time of vibration input in the frequency region that becomes idle vibration and booming noise can be improved by vibration of the elastic body and the movable plate.

  Further, the dynamic spring constant can be minimized by exciting the movable plate with a linear actuator capable of controlling the thrust of the output shaft with high accuracy to control the fluid pressure in the fluid chamber. That is, in this vibration isolator, active performance can be obtained by vibration of the movable plate.

  As described above, according to this vibration isolator, the synergistic effect of the rise suppression effect of the dynamic spring constant by the elastic body or the like and the reduction effect of the dynamic spring constant by the movable plate, the high-frequency region in which the idle vibration and the booming noise are generated. Can be effectively absorbed.

  According to the linear actuator and the vibration isolator according to the present invention, it is possible to obtain an excellent effect that the fluctuation of the thrust when the linear actuator is driven can be suppressed and the thrust can be controlled with high accuracy.

It is a partially broken perspective view which shows a linear actuator. It is a disassembled perspective view which shows a linear actuator. (A) It is a perspective view showing typically the state where the first magnet is attracted by the second magnet and repels the third magnet. (B) It is a perspective view which shows typically the state in which a 1st magnet is attracted | sucked by a 3rd magnet and repels a 2nd magnet. (A) It is a perspective view which shows the state which the extension amount of the output shaft reduced corresponding to the state of FIG. 3 (A). (B) It is a perspective view which shows the state which the extension amount of the output shaft increased corresponding to the state of FIG. 3 (B). It is sectional drawing which shows a vibration isolator.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
[Linear actuator]
In FIG. 1, a linear actuator 100 according to the present embodiment includes a motor 102, a movable portion 104, a rotating portion 106, a spring member 108 as an example of a limiting portion, and a case 118 as an example of a fixed member. Yes.

  The motor 102 is, for example, an electric motor (DC motor), and a rotating shaft 114 protrudes from a main body 110 that is an example of a portion that does not rotate during operation.

  In the movable portion 104, the first magnet 111 and the output shaft 116 are combined. Specifically, the first magnet 111 is formed in an annular shape, for example, and an output shaft 116 is attached to the center thereof. The axial direction A of the output shaft 116 is orthogonal to the radial direction of the first magnet 111. The axial direction A coincides with the axial direction of the rotating shaft 114 of the motor 102. The output shaft 116 is provided with a flange 116A to which one end of the spring member 108 is fixed.

  The opposing surfaces 111A and 111B, which are both surfaces in the thickness direction of the first magnet 111, have, for example, two magnetic poles S and N that are alternately different in the rotation direction R of the rotating unit 106, respectively. The magnetic poles S and N are respectively disposed in 90 ° ranges obtained by dividing the opposing surfaces 111A and 111B into four equal parts in the circumferential direction. In the opposing surfaces 111A and 111B, the opposite side of the magnetic pole S in the thickness direction is the magnetic pole N, and the opposite side of the magnetic pole N in the thickness direction is the magnetic pole S. The facing surface 111A is a surface facing a second magnet 112 described later. The facing surface 111B is a surface facing a third magnet 113 described later.

  The rotating unit 106 is disposed on one side and the other side of the first magnet 111 in the axial direction A of the output shaft 116 so as to face the first magnet 111 with gaps D1 and D2, respectively, and is nonmagnetic. A second magnet 112 and a third magnet 113 are connected and integrated by a body 120. The second magnet 112 and the third magnet 113 are each formed in an annular shape, for example, and annular yokes 122 and 123 are attached in close contact with the opposite side of the first magnet 111 in the axial direction A. Yes. The outer diameter and thickness of the yoke 122 are equal to the outer diameter of the second magnet 112. Similarly, the outer diameter and thickness of the yoke 123 are equal to the outer diameter of the third magnet 113.

  The non-magnetic body 120 is, for example, two rod-like members having the same shape, and the yoke 122 and the second magnet 112, and the third magnet 113 and the yoke 123 are point-symmetric in the circumferential direction. It is connected at two points. The arrangement of the nonmagnetic material 120 takes into account the vibration balance of the rotating unit 106. A notch 120 </ b> A (relief) for preventing contact between the first magnet 111 and the nonmagnetic body 120 is formed in the central portion in the longitudinal direction of the surface on the center side of the rotating portion 106 of the nonmagnetic body 120. .

  The rotating unit 106 is driven to rotate about the axial direction A by the motor 102. In the present embodiment, the rotating shaft 114 of the motor 102 is connected to the center of the second magnet 112. The rotating shaft 114 may be connected to the center of the yoke 122.

  The rotating unit 106 supports the movable unit 104 so as to be movable in the axial direction A. Specifically, a bearing 124 that supports the output shaft 116 of the rotating unit 106 is provided at the center of the yoke 123. An output shaft 116 is inserted through the bearing 124. The output shaft 116 is supported by a bearing 124 so as to be slidable in the axial direction A. The flange 116A is located on the opposite side of the bearing 124 from the motor 102 side.

  In the rotating unit 106, the opposing surfaces 112 </ b> A and 113 </ b> A of the second magnet 112 and the third magnet 113 have magnetic poles S and N that are alternately different in the rotation direction R of the rotating unit 106, for example, at two locations. ing. The magnetic poles S and N are respectively arranged in 90 ° ranges obtained by dividing the opposing surfaces 112A and 113A into four equal parts in the circumferential direction. The facing surface 112 </ b> A of the second magnet 112 is a surface facing the facing surface 111 </ b> A of the first magnet 111. The facing surface 113 </ b> A of the third magnet 113 is a surface facing the facing surface 111 </ b> B of the first magnet 111. In the second magnet 112 and the third magnet 113, the magnetic poles S and N of the facing surfaces 112A and 113A have the same phase in the rotation direction R, and the same magnetic pole S and the magnetic pole N face each other in the axial direction A. ing.

  The spring member 108 is, for example, a coil spring that limits the moving range of the movable portion 104 so that the first magnet 111 is not attracted to the second magnet 112 or the third magnet 113. One end of the spring member 108 is fixed to, for example, the flange 116 </ b> A of the output shaft 116, and the other end is fixed to the case 118. The spring member 108 generates a repulsive force with respect to the movement of the movable portion 104 in the axial direction A and the rotational direction R, respectively.

  The case 118 is provided on the opposite side of the rotating unit 106 in the axial direction A from the motor 102 side, and the output shaft 116 is inserted therethrough and is fixed to a portion that does not rotate when the motor 102 is operated. As an example, the case 118 includes a cylindrical portion 126, a bottom portion 128, and a flange portion 130. The cylindrical part 126 is a part that houses most of the movable part 104 and the rotating part 106, and is fitted to the main body part 110 of the motor 102, for example. A configuration in which the cylindrical portion 126 completely covers the motor 102 may be employed. A through hole 130 </ b> A through which the output shaft 116 of the movable portion 104 is inserted is formed in the bottom portion 128. The bottom portion 128 functions as a mounting bracket when the linear actuator 100 is mounted on the vibration isolator 10 described later.

(Function)
This embodiment is configured as described above, and the operation thereof will be described below. 3A, in the linear actuator 100 according to this embodiment, in the second magnet 112 and the third magnet 113, the magnetic poles S and N of the facing surfaces 112A and 113A have the same phase in the rotation direction R. The same magnetic poles S and magnetic poles N face each other in the axial direction A. Therefore, as shown in FIG. 3A, when an attractive force is generated between the first magnet 111 and the second magnet 112, the first magnet 111 and the third magnet 113 are interposed. A repulsive force is generated. The directions of the attractive force and the repulsive force are the same direction, and the movable portion 104 moves in that direction. At this time, since the moving range of the first magnet 111 is limited by the spring member 108, the first magnet 111 is not attracted to the second magnet 112. Thereby, as shown in FIG. 4A, the extension amount of the output shaft 116 decreases. In other words, the output shaft 116 contracts.

  As shown in FIG. 3B, when the rotating unit 106 rotates in the rotation direction R, the magnetic poles S and N of the second magnet 112 and the third magnet 113 facing the first magnet 111 are reversed. A repulsive force is generated between the first magnet 111 and the second magnet 112, and an attractive force is generated between the first magnet 111 and the third magnet 113. The directions of the attractive force and the repulsive force are opposite to those before the rotation of the rotating unit 106, and the movable unit 104 moves in that direction. At this time, since the moving range of the first magnet 111 is limited by the spring member 108, the first magnet 111 is not attracted to the third magnet 113. Thereby, as shown in FIG. 4B, the extension amount of the output shaft 116 increases. In other words, the output shaft 116 extends.

  Since the first magnet 111 is combined with the output shaft 116 in the movable portion 104, positive and negative axial forces (thrust) are alternately applied to the movable portion 104 when the rotating portion 106 is continuously rotated by the motor 102. Occur. Thereby, the movable part 104 vibrates.

  In the rotation unit 106, the second magnet 112 and the third magnet 113 are connected and integrated by the non-magnetic material 120, so that the second magnet 112 and the third magnet are rotated when the rotation unit 106 rotates. The axial distance from 113 does not change. Therefore, even if the movable part 104 moves and the axial position of the first magnet 111 changes, the axial distance between the second magnet 112 and the first magnet 111, and the first magnet 111 The total sum with the distance in the axial direction between the third magnet 113 does not change. As a result, even if the axial position of the movable portion 104 changes, the fluctuation of the total magnetic force passing through the first magnet 111 is suppressed. For this reason, the fluctuation | variation of the thrust of the movable part 104 at the time of the drive of the linear actuator 100 can be suppressed, and this thrust can be controlled with high precision.

  Further, in the linear actuator 100, the spring member 108 as the limiting portion generates a repulsive force with respect to the movement of the movable portion 104 in the axial direction A and the rotational direction R. Accordingly, when the rotating unit 106 is rotated by the motor 102, the first magnet 111 of the movable unit 104 is not attracted to the second magnet 112 or the third magnet 113, and the movable unit 104 is moved to the rotating unit 106. Circulation is suppressed. For this reason, the thrust of the movable part 104 can be generated efficiently and stably.

  Furthermore, by using a DC motor as the motor, the linear actuator 100 can be reduced in size and price.

[Vibration isolator]
In FIG. 5, the vibration isolator 10 according to the present embodiment is applied as an engine mount that supports, for example, an engine that is an example of a vibration generating unit in an automobile to a vehicle body that is an example of a vibration receiving unit. 5 indicates the axis of the vibration isolator 10, and the direction along the axis coincides with the axial direction A of the output shaft 116 in the linear actuator 100. The vibration isolator 10 includes a first mounting member 12, a second mounting member 20, a rubber elastic body 16 as an example of an elastic body, a main liquid chamber 36 and a sub liquid chamber 38 as an example of a liquid chamber, The movable plates 49 and 50 and the linear actuator 100 are included.

  The first attachment member 12 is connected to either the vibration generating unit or the vibration receiving unit, for example, the engine side. The second mounting member 20 is connected to either the vibration generating part (not shown) or the vibration receiving part (not shown), for example, the vehicle body side.

  The second mounting member 20 includes an outer cylinder 22 and an intermediate cylinder 24. The outer cylinder 22 includes a cylindrical portion 22A having a substantially cylindrical shape, a flange portion 22B extending radially outward from one end of the cylindrical portion 22A, an end portion of the intermediate cylinder 24 on the other end side of the cylindrical portion 22A, and will be described later. A caulking portion 22C is provided for caulking and fixing the sealing plate 40 and the like. The intermediate cylinder 24 has a substantially cylindrical shape having a smaller diameter than the cylindrical portion 22 </ b> A, and is coaxially disposed on the radially inner side of the outer cylinder 22. One end side of the intermediate cylinder 24 is a curved portion 24A that is slightly curved radially outward, and the other end side is a stepped flange portion 24B that is bent radially outward. A bolt hole 22 </ b> H for connection with the rebound stopper fitting 13 is drilled in the flange portion 22 </ b> B of the outer cylinder 22. The rebound stopper fitting 13 has a rubber material 13A disposed inside the top that is curved in a substantially U shape, and is fixed to the second attachment member 20 by a bolt 13C at the attachment portion 13B. The rebound stopper fitting 13 is disposed so as to surround the upper outer side of the vibration isolator 10.

  The second mounting member 20 is connected to a vehicle body (not shown) as a vibration receiving portion via a leg member 96 described later.

  The first mounting member 12 has a substantially cylindrical shape whose outer diameter is smaller than the inner diameter of the second mounting member 20, is coaxial with the second mounting member 20, and is larger than the second mounting member 20. It is arranged to protrude outward. The second mounting member 20 side of the first mounting member 12 has a substantially tapered shape so that the diameter decreases toward the tip. The first attachment member 12 is connected to an engine (not shown) by an attachment portion (not shown).

  The rubber elastic body 16 is a member that connects the first mounting member 12 and the second mounting member 20 and is deformed in accordance with vibration input from the engine side. The rubber elastic body 16 is vulcanized and bonded to the outer periphery of the first attachment member 12 on the small-diameter side end, and is added so as to cover the outer periphery of the curved portion 24A on the inner periphery of the intermediate tube 24 on the curved portion 24A side. The first attachment member 12 and the intermediate cylinder 24 are elastically connected to each other. A recess 16A is formed on the lower surface of the rubber elastic body 16 (the surface on the second attachment member 20 side). A thin upper film 17 that covers the outer peripheral surface of the first mounting member 12 is integrally formed with the rubber elastic body 16. The rubber elastic body 16 is integrally formed with a thin lower film 18 that extends toward the stepped flange portion 24 </ b> B of the intermediate cylinder 24 and covers the inner peripheral surface of the intermediate cylinder 24.

  A diaphragm 30 is vulcanized and bonded to the inside of the cylindrical portion 22A of the outer cylinder 22. The diaphragm 30 is made of a thin rubber film and has a substantially cylindrical shape. One end of the cylinder of the diaphragm 30 is bent radially inward and reduced in diameter, and is vulcanized and bonded to the ring 34. The ring 34 is externally fitted to the first attachment member 12 via the upper film 17. The other end of the cylinder of the diaphragm 30 extends toward the caulking portion 22C side of the outer cylinder 22, and constitutes a coating film 32 that covers the inner peripheral surface of the cylindrical portion 22A.

  The main liquid chamber 36 and the sub liquid chamber 38 are portions that are filled with liquid and expand and contract due to deformation of the rubber elastic body 16. Specifically, the sealing plate 40 is disposed on the opposite side of the second mounting member 20 from the first mounting member 12. The main liquid chamber 36 as a pressure receiving chamber is configured to be surrounded by the concave portion 16 </ b> A of the rubber elastic body 16, the intermediate cylinder 24, and the sealing plate 40. The auxiliary liquid chamber 38 is formed in an annular shape between the rubber elastic body 16 and the diaphragm 30. A restriction passage 26 is formed between the outer cylinder 22 and the intermediate cylinder 24 which are the outer peripheral sides of the main liquid chamber 36. The restriction passage 26 has one end communicating with the main liquid chamber 36 and the other end communicating with the sub liquid chamber 38, and the main liquid chamber 36 and the sub liquid chamber 38 are communicated with each other through the restriction passage 26. The main liquid chamber 36, the sub liquid chamber 38, and the restriction passage 26 are filled with liquid.

  When vibration in the axial direction A is input from the side of the first mounting member 12 connected to the engine, the rubber elastic body 16 is elastically deformed, and the internal volume of the main liquid chamber 36 is expanded and contracted along with this elastic deformation. As a result, vibrations in a relatively low frequency range among vibrations input from the engine, such as shake vibrations, are input into the main liquid chamber 36 due to a pressure difference between the main liquid chamber 36 and the sub liquid chamber 38. The liquid and the liquid sealed in the sub liquid chamber 38 circulate through each other through the restriction passage 26, and a vibration damping effect and a vibration isolation effect can be obtained by a liquid column resonance action in the restriction passage 26. The restriction passage 26 is set so that its path length and cross-sectional area can effectively exert a damping effect in a frequency range of low-frequency large-amplitude vibration such as engine shake.

  The sealing plate 40 is generally disc-shaped as a whole, and has an annular outer peripheral plate portion 42 with a circular opening 41 formed in the center, a movable plate portion 44 disposed inside the opening 41, and an annular shape And a rubber part 46. The annular rubber portion 46 connects the outer peripheral plate portion 42 and the movable plate portion 44, and the movable plate portion 44 is elastically supported by the outer peripheral plate portion 42 by the rubber portion 46. The outer peripheral plate portion 42 is bent at the outer peripheral end downward, is crimped together with the stepped flange portion 24 </ b> B of the intermediate cylinder 24, and is fixed to the second mounting member 20. Further, the outer peripheral plate portion 42 is bent upward so that the inner peripheral end constituting the opening 41 has a cylindrical shape. Note that the outer peripheral plate portion 42 of the present embodiment is a press-formed product made of a metal plate.

  A movable plate forming window 47 is formed outside the opening 41 in the outer peripheral plate portion 42 in the radial direction. The movable plate forming window 47 is an arc-shaped elongated hole, and the center of the radius of curvature thereof coincides with the center (axial center CL) of the outer peripheral plate portion 42. In the present embodiment, for example, three movable plate forming windows 47 are arranged so as to surround the opening 41. The rubber portion 46 is vulcanized and bonded along the upper surface and the lower surface of the outer peripheral plate portion 42 radially outward from the opening 41 and closes the movable plate forming window 47. The closed portion is configured as a movable plate 49 that is elastically deformed by a change in the hydraulic pressure of the main liquid chamber 36.

  The movable plate 50 includes a rubber portion 46 positioned inside the opening 41 in the sealing plate 40 and a movable plate portion 44. An output shaft 116 of a linear actuator 100 described later is inserted into the central portion of the movable plate portion 44. The outer peripheral end of the movable plate portion 44 is bent upward.

  One side of the movable plates 49 and 50 faces the main liquid chamber 36. A linear actuator 100 is arranged on the opposite side of the sealing plate 40 from the main liquid chamber 36. The linear actuator 100 is disposed on the other surface side of the movable plate 50 and configured to vibrate the movable plate 50.

(Function)
The vibration isolator 10 is configured as described above, and the operation thereof will be described below. The vibration isolator 10 is used, for example, for vibration isolation of an automobile engine. In this case, the automobile engine is supported by the plurality of vibration isolation devices 10 on the body of the automobile. Specifically, when the first mounting member 12 of the vibration isolator 10 is connected to, for example, an automobile engine that is a vibration generation source, and the second mounting member 20 is connected to, for example, the vehicle body that is a vibration receiving unit, the automobile engine is The first mounting member 12, the rubber elastic body 16, and the second mounting member 20 are supported by the vehicle body. At this time, the vibration of the automobile engine is absorbed by the resistance based on the internal friction of the rubber elastic body 16.

  When vibration with a relatively low frequency (for example, frequency of 10 to 15 Hz) such as engine shake is input, the vibration is transmitted to the rubber elastic body 16, thereby elastically deforming the rubber elastic body 16 and causing the main liquid. The chamber 36 expands and contracts, the internal liquid moves between the main liquid chamber 36 and the sub liquid chamber 38 via the restriction passage 26, and the passage resistance or liquid column resonance when the internal liquid moves back and forth through the restriction passage 26. The vibration is absorbed by.

  The vibration isolator including the rubber part 46 and the movable plate 49 is, for example, an engine shake having a frequency of 10 to 15 Hz and a frequency range higher than the riding comfort range (idle to booming sound: for example, a frequency of less than 20 to 100 Hz). The dynamic spring constant can be lowered as compared with the case where the rubber part 46 and the movable plate 49 are not provided and the case where the rubber part 46 is provided and the movable plate 49 is not provided. It should be noted that by adjusting the rigidity and the like of the rubber part 46 and the movable plate 49, it is also possible to suppress an increase in the dynamic spring constant in a part of the high frequency region (the low frequency side close to the noise in the high frequency region).

  Here, in the vibration isolator 10, since the rubber part 46 and the movable plate 49 face the main liquid chamber 36, the rigidity (area, thickness, hardness, etc.) of the rubber part 46 and the movable plate 49 are determined. ) Is set appropriately, the rubber part 46 and the movable plate 49 are vibrated at the time of vibration input in the frequency domain that causes idle vibration and a booming sound, thereby suppressing an increase in the dynamic spring constant of the vibration isolator 10. it can. In other words, in the vibration isolator 10, the passive performance at the time of vibration input in the frequency region that becomes idle vibration and booming noise can be improved by the vibration of the rubber part 46 and the movable plate 49.

  For example, when the frequency of vibration rises from idle vibration with a frequency of 20 to 40 Hz to high frequency vibration with a frequency of 100 to 200 Hz, the restriction passage 26 becomes clogged. If it does so, the hydraulic pressure of the main liquid chamber 36 will rise, the dynamic spring constant of the vibration isolator 10 will rise, and vibration isolation performance will fall. In this case, the linear actuator 100 capable of controlling the thrust of the output shaft 116 with high accuracy causes the movable plate 50 to vibrate in a direction in which the vibration transmission force to the vehicle body is zero, thereby controlling the hydraulic pressure in the main liquid chamber 36. An increase in the dynamic spring constant can be suppressed. That is, in the vibration isolator 10, active performance can be obtained by the vibration of the movable plate 50.

  At this time, in addition to the effect of suppressing the increase of the dynamic spring constant by the rubber portion 46, the effect of suppressing the increase of the dynamic spring constant by the movable plate 49 is added. The amount can be reduced. Thereby, the power consumption of the linear actuator 100 can be reduced and it can also contribute to a fuel-consumption improvement.

  Therefore, in the vibration isolator 10 according to the present embodiment, idle vibration and bulking are caused by a synergistic effect of the suppression effect of the dynamic spring constant by the rubber portion 46 and the movable plate 49 and the reduction effect of the dynamic spring constant by the movable plate 50. It becomes possible to effectively absorb the vibration in the high frequency region that becomes sound.

  The temperature of the vibration isolator 10 rises due to the heat from the engine, and the air in the space may expand. However, the pressure in the space is caused by the movable plate 49 being deformed to the main liquid chamber 36 side. The rise is suppressed, and unnecessary pressure is not applied to the movable plate portion 44 and the rubber portion 46, so that the deterioration of the vibration proof property is suppressed, and the rubber portion 46 supporting the movable plate portion 44 is stretched. It can be suppressed.

  Furthermore, in the vibration isolator 10 according to the present embodiment, the movable plate 49 is provided in a vacant space outside the opening 41 in the outer peripheral plate portion 42 in the radial direction, and the space is effectively used. There is no need to forcibly provide the movable plate 49 to the members 22 and the intermediate cylinder 24. If the movable plate 49 is provided on the members such as the outer cylinder 22 and the intermediate cylinder 24, the anti-vibration characteristics at the time of low-frequency vibration input are affected by the effect that the size of the restriction passage 26 is shortened.

  Furthermore, in the vibration isolator 10 of the present embodiment, the outer peripheral plate portion 42, the movable plate portion 44, the rubber portion 46 that connects the outer peripheral plate portion 42 and the movable plate portion 44, and the movable plate 49 are formed. Since the rubber part 46 is integrated into a unit, the assembly process is made efficient, and the type of rubber used in the vibration isolator 10 can be minimized.

  Further, the vibration isolator 10 of the present embodiment is provided with a rubber portion 46 (a portion connecting the outer peripheral plate portion 42 and the movable plate portion 44) and a movable plate 49 so as to face the main liquid chamber 36. Therefore, the rigidity of the rubber part 46 (movable plate 50) supporting the movable plate part 44 can be set with emphasis on active performance, and the rigidity of the movable plate 49 can be set with emphasis on passive performance. For this reason, both passive performance and active performance can be achieved.

[Other Embodiments]
The motor 102 is not limited to an electric motor (DC motor), and may be a pressure motor such as a hydraulic motor or a pneumatic motor.

  The rotation shaft 114 of the motor 102 is connected to the center of the second magnet 112 in the rotation unit 106. However, the present invention is not limited to this, and a gear between the rotation shaft 114 of the motor 102 and the rotation unit 106 is used. A power transmission mechanism such as a row may be interposed. That is, the rotating shaft 114 of the motor 102 and the rotating unit 106 do not have to be arranged coaxially.

  Although the spring member 108 has been described as an example of the limiting portion, the limiting portion is not limited to this. For example, in FIG. 1, the position of the lower end of the notch 120 </ b> A of the non-magnetic body 120 is set slightly above the second magnet 112, and the position of the upper end of the notch 120 </ b> A is slightly higher than the third magnet 113. Set to the bottom. Further, the notch 120A is formed deeper. Then, the outer diameter of the first magnet 111 is slightly larger than the outer diameters of the second magnet 112 and the third magnet 113 so as not to interfere with the notch 120A of the non-magnetic body 120. Thereby, the movement range of the first magnet 111 in the axial direction A is limited by the upper end and the lower end of the notch 120A. The restriction unit may be configured in this way.

DESCRIPTION OF SYMBOLS 10 ... Vibration isolator, 12 ... 1st attachment member, 16 ... Rubber elastic body (elastic body), 20 ... 2nd attachment member, 36 ... Main liquid chamber (liquid chamber), 38 ... Sub liquid chamber (liquid chamber) ), 50 ... movable plate, 100 ... linear actuator, 102 ... motor, 104 ... movable part, 106 ... rotating part, 108 ... spring member (restricting part), 111 ... first magnet, 111A ... facing surface, 111B ... facing 112, second magnet, 112A, facing surface, 113, third magnet, 113A, facing surface, 116, output shaft, 118, case (fixing member), 120, nonmagnetic material, A, axial direction, D1 ... Gap, D2 ... Gap, N ... Magnetic pole, S ... Magnetic pole

Claims (3)

A motor,
A movable part in which the first magnet and the output shaft are combined;
The one side and the other side of the first magnet in the axial direction of the output shaft are opposed to the first magnet with a gap, and are connected and integrated by a non-magnetic material. A rotating part having a second magnet and a third magnet, driven to rotate about the axial direction by the motor, and supporting the movable part movably in the axial direction;
A limiting unit that limits a moving range of the movable unit so that the first magnet is not attracted to the second magnet or the third magnet,
The opposing surfaces of the first magnet, the second magnet, and the third magnet have magnetic poles that are alternately different in the rotation direction of the rotating unit,
A linear actuator in which, in the second magnet and the third magnet, the magnetic poles of the opposing surfaces are in the same phase in the rotation direction, and the same magnetic poles oppose each other in the axial direction. A fixing member provided on the opposite side of the rotating portion from the motor side in the axial direction, the output shaft being inserted, and a fixing member fixed to a portion that does not rotate during operation of the motor;
The limiting portion is a spring member that has one end fixed to the output shaft and the other end fixed to the fixing member, and generates a repulsive force with respect to the movement of the movable portion in the axial direction and the rotational direction, respectively. The linear actuator according to claim 1. A first attachment member connected to either the vibration generating unit or the vibration receiving unit;
A second mounting member connected to either the vibration generating unit or the vibration receiving unit;
An elastic body that connects the first mounting member and the second mounting member and deforms in accordance with vibration input from the vibration generating unit;
A liquid chamber enclosing a liquid and expanding and contracting by deformation of the elastic body;
A movable plate having one surface facing the liquid chamber;
The linear actuator according to claim 1 or 2, wherein the linear actuator is disposed on the other surface side of the movable plate and vibrates the movable plate.
A vibration isolator.

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