JP2010014174A - Active vibration control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To constitute an active vibration control device capable of restraining vibrations of different frequencies. <P>SOLUTION: An exciter 10 reciprocating in the direction of the vibration axis X by magnetism acting from an electromagnetic solenoid SL, is provided in a main housing 1, and a spring body 21 capable of changing a spring constant by rotational operation, is provided in a base housing 2, and is also linked with a center rod 13 of the exciter 10. A control unit 30 sets a rotational attitude of the spring body 21 in response to a frequency of vibration from an external part based on a signal from a sensor unit 30S, and supplies driving electric power corresponding to the frequency of the vibration from the external part, a phase of the vibration and a level of the vibration to the electromagnetic solenoid SL. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an active vibration isolator, and more particularly to a technique for actively suppressing vibration from a vibration source by driving and vibrating a vibrating body.

  There exist what is shown by patent document 1 and patent document 2 as an active vibration isolator comprised as mentioned above.

  In Patent Document 1, the coil 18 is wound around the outer periphery of the intermediate shaft 30 between the upper and lower yoke members 20, 12, and the vibration member 14 is disposed on the outer periphery thereof. By providing the leaf spring 16 over the spacer 62 of the upper and lower yoke fittings 20 and 12 and the spacer 64 of the vibration fitting 14, the vibration fitting 14 can be displaced in the vertical direction relative to the system of the yoke fittings 20 and 21. It becomes the structure supported by.

  By adjusting the electric power to the coil 18 in the apparatus having this configuration, the vibration fitting 14 is operated in one direction with respect to the system of the yoke fittings 20 and 21 and restored to the original position by the urging force of the leaf spring 16. The vibration is suppressed by reciprocating vertically and utilizing the action of resonance.

  In Patent Document 2, a movable mass 7 guided up and down by a shaft 4 with respect to the main frame 2 is supported, and coil springs 14 and 15 are provided that elastically support the movable mass 7. The permanent magnet 10 is provided with a configuration in which an electromagnetic force is applied to the electromagnetic coil 13 provided in the main frame 2 to generate vibration. An adjustment mass 16 is fixed to the lower end of the shaft 4 so that the disc 17 fixed to the shaft 4 can be magnetically attached to or separated from the movable mass 7.

  In this configuration, when the disc 17 is not magnetically attached to the movable mass 7, a mass (small mass state) constituted by the movable mass 7, the permanent magnet 10, and the ring member 11 acts on the coil springs 14 and 15. When the disc 17 is magnetically attached to the movable mass 7, the disc 17, the shaft 4, and the adjustment mass 16 are integrated with the movable mass 7, and the movable mass 7, the permanent magnet 10, A mass (a large mass state) configured by the ring member 11, the disc 17, the shaft 4, and the adjustment mass 16 acts.

  By switching between the small mass state and the large mass state in this way, the resonance frequency changes and it is possible to cope with a plurality of vibrations that can be suppressed.

JP-A-2002-181126 (paragraph numbers [0030 to 0057], FIGS. 1 to 3) JP-A-6-74294 (paragraph numbers [0008 to 0023], FIGS. 1 to 4)

  However, in the apparatus described in Patent Document 1, since a large excitation force is created using spring resonance, a vibration suppression effect for a specific frequency can be obtained, but vibration of a different frequency is not generated. There is room for improvement because it cannot be effectively controlled.

  Therefore, it is possible to adopt the configuration described in Patent Document 2. However, in Patent Document 2, since the resonance frequency is switched by switching the mass acting on the spring, a heavy object is inevitably required, resulting in inconvenience that leads to an increase in the weight and size of the device. Met.

  In particular, considering the vibrations generated in automobiles, the vibrations transmitted to the vehicle body fluctuate due to factors such as fluctuations in engine rotation speed, gear setting of the transmission system, and driving of fans in the ventilation system in the car. Therefore, suppression against such different vibrations is demanded.

  An object of the present invention is to rationally configure an active vibration isolator capable of suppressing vibrations of different frequencies.

  A feature of the present invention is that a vibration body that reciprocates in the direction of the drive axis by magnetism acting from an electromagnetic solenoid is supported by the housing via a support spring, and is linked to the vibration body via a linkage portion. In addition, a resonance unit having a spring body capable of changing the spring constant is provided.

  With this configuration, the vibration from the external vibration source can be suppressed by reciprocating the vibrating body in the direction of the vibration axis so as to have a frequency equal to the resonance frequency by magnetism acting from the electromagnetic solenoid. Also, by changing the spring constant of the spring body of the resonance unit, the spring force acting from the spring body on the vibrating body also changes via the linkage part, so the resonance frequency can be changed, and the frequency of the vibration source varies In addition, vibration at that frequency can also be suppressed. Furthermore, in the present invention, since the resonance frequency can be changed by changing the spring constant of the spring body of the resonance unit, it is not necessary to provide a heavy object used for changing the resonance frequency. Therefore, an active vibration isolator capable of suppressing vibrations at different frequencies has been configured without causing an increase in size.

  In the present invention, the resonance unit has a rod-shaped spring body having a cross-sectional shape having a different width and thickness in the radial direction, and the spring body is supported by the housing so as to be rotatable around an axis in the longitudinal direction. It may be configured with a bearing portion. According to this, it is possible to change the resonance frequency by changing the spring constant in the vibration axis direction simply by changing the rotation posture of the rod-shaped spring body, and as a result, it is possible to suppress vibration corresponding to vibrations in a wide range of frequencies. It becomes.

  According to the present invention, there is provided an interlocking mechanism in which the pair of spring bodies are arranged in a parallel posture at a position sandwiching the vibration axis, and the rotational posture of the pair of spring bodies is maintained in a symmetric posture across the vibration axis. The actuator which is provided and sets the rotation attitude | position around the said axis center in each spring body may be provided. According to this, since the postures of a pair of symmetrically arranged spring bodies are changed equally, vibration can be suppressed without causing resonance bias.

  In the present invention, the resonance unit may include the spring body formed by forming a wire rod in a coil shape, and a fitting body in which a groove portion capable of adjusting a fitting amount with respect to the spring body is formed. According to this, the spring constant of the spring body will be changed by adjusting the amount of fitting between the coiled spring body and the fitting body, and the spring constant will be changed steplessly to handle vibrations in a wide range of frequencies. Thus, vibration can be suppressed.

  In the present invention, the resonance unit may include the arm-like spring body in a posture orthogonal to the vibration axis, and a weight supported movably with respect to the spring body. According to this, by simply adjusting the position of the weight with respect to the arm-shaped spring body, the spring constant can be changed steplessly to suppress vibration corresponding to vibrations in a wide range of frequencies.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
As shown in FIG. 1, the active vibration isolator of the present invention is arranged in a positional relationship in which a cylindrical main housing 1, a base housing 2 on the base end side, and a plate-like bottom wall 3 are overlapped, A case 4 covering the main housing 1 is provided. The main housing 1 includes an electromagnetic solenoid SL, and a vibration body 10 is provided inside the main housing 1 so as to be reciprocally movable along the vibration axis X by the action of magnetism from the electromagnetic solenoid SL. Further, the active vibration isolator includes a resonance unit 20 having a spring body 21 capable of changing a spring constant in the base housing 2, and a control unit 30 for controlling them.

  This active vibration isolator is provided in the body of a vehicle such as an automobile or the frame of a seat, and is active by generating resonance vibration corresponding to the frequency, phase, and vibration level of a vibration source such as an engine. It has a damper function to suppress vibration.

  In automobiles, the frequency and acceleration (amplitude) of the vibration from the engine in the idling state and the vibration from the engine in the traveling state are different, and the frequency and acceleration from the engine differ depending on the shift stage even in the traveling state. is there. Thus, in this active vibration isolator, the resonance frequency can be changed by changing the spring constant of the spring body 21 of the resonance unit 20 in the direction of the vibration axis X so that vibrations having different frequencies and the like can be suppressed. It is configured.

  Although this active vibration isolator is not necessarily installed in the posture shown in FIG. 1, the main housing 1 will be described as the upper side and the base housing 2 as the lower side, as shown in FIG.

  The main housing 1 has a cylindrical inner surface centering on the vibration axis X in a vertically oriented posture, and an electromagnetic solenoid SL in which a linear conductor having an insulating film is wound in a coil shape on the upper and lower portions. The ring-shaped fixed yoke 5 is disposed on the inner surface side of each electromagnetic solenoid SL. The electromagnetic solenoid SL has a structure in which a conductor is wound around the bobbin 6, and the main housing 1 has a structure in which three members are combined so that the bobbin 6 can be set.

  The upper and lower electromagnetic solenoids SL are wound in opposite directions so that current flows in the opposite direction when driving power is supplied (see FIG. 4), and the upper electromagnetic solenoid SL of the upper electromagnetic solenoid SL is supplied when driving power is supplied. Magnetic poles of the same polarity appear on the upper side and the lower side of the lower electromagnetic solenoid SL.

[Exciter]
The vibrating body 10 includes a disc-shaped magnet 11 (permanent magnet) in which different magnetic poles (one N pole and the other S pole) appear on the upper surface and the lower surface, and iron disposed in close contact with the upper surface and the lower surface. The movable yoke 12 is made of a disk-like magnetic material such as a center rod 13 and passes through the movable yoke 12 in the vertical direction. From such a configuration, a magnetic circuit is formed by the magnet 11, the movable yoke 12, the fixed yoke 5 of the main housing 1, and the electromagnetic solenoid SL.

  The vibration body 10 is disposed in a state of being sandwiched between support springs 14 provided on the upper surface and the lower surface of the main housing 1, and the center rod 13 penetrates the support spring 14 in the vertical direction and is screwed into the upper thread portion. It is fixed by a mating nut 15.

  The support spring 14 is formed of a spring material such as a steel plate into a disk shape, and slits (not shown) for easily performing elastic deformation are formed in a spiral shape or a radial shape. The support spring 14 may be a strip-shaped plate spring or a coiled spring.

  These are integrally connected by connecting bolts 16 that pass through the support spring 14 on the upper surface of the main housing 1, the main housing 1, and the support spring 14 on the lower side of the main housing 1 and are screwed into the base housing 2.

[Resonance unit]
As shown in FIGS. 1 to 3, the resonance unit 20 includes a rod-shaped spring body 21 arranged at a position parallel to the vibration axis X on a virtual plane that is in a posture orthogonal to the vibration axis X, and A bearing portion 22 is provided that is supported on the base housing 2 so as to be rotatable about an axis along the longitudinal direction of the spring body 21.

  Further, the resonance unit 20 includes a pair of gears 23 (an example of an interlocking mechanism) that mesh with each other so as to maintain the rotational posture of the spring body 21 in a symmetrical posture with the vibration axis X interposed therebetween, and the spring body 21. A rotary encoder 24 for measuring a rotation angle and an electric motor 25 as an actuator for setting the rotation posture of the spring body 21 via an output gear 25A are provided. Note that a toothed belt, an endless chain, or the like may be used as the interlocking mechanism, or a mechanical linkage structure combining a link member and a rod may be used.

  The spring body 21 is formed into a shape having a plate-like portion 21A having a width equal to the diameter of the material and a thickness T smaller than the width W by processing two portions of the material having a circular cross-sectional shape. Yes. Further, the engagement portion 21B having a circular cross-sectional shape at the center position in the longitudinal direction of the spring body 21 is engaged with a pair of recesses 13B formed at the lower end portion of the center rod 13. The engaging portion 21B and the concave portion 13B constitute a linkage portion of the present invention. Moreover, in this invention, the structure which penetrates the engaging part 21B of the spring body 21 as a linkage part in the through-hole drilled in the center rod 13 may be sufficient.

  The pair of gears 23 as the interlocking mechanism maintains a posture in which the posture of the plate-like portion 21A is symmetrical as shown in FIGS. 3A and 3B when viewed in the direction along the axis of the spring body 21. Spur gears with the same number of teeth are used.

  In the present invention, instead of the configuration in which the rotation posture of the spring body 21 is set by the electric motor 25, a configuration in which the rotation posture of the spring body 21 is set by human operation may be employed.

From such a configuration, the resonance frequency of the active vibration isolator is determined by the spring constant of the support spring 14, the spring constant of the spring body 21, and the weight of the vibrating body 10.
〔Controller unit〕
As shown in FIG. 4, the control unit 30 includes an input system for signals from a sensor unit 30S formed of an acceleration sensor or the like so as to detect the frequency, phase, and vibration level of an external vibration source.

  The control unit 30 includes a vibration determination unit 31 that determines the frequency, phase, and level of vibration input from the sensor unit 30S, and supplies the electromagnetic solenoid SL based on the determination result of the vibration determination unit 31. The rotation posture of the spring body 21 so as to change the resonance frequency in the resonance unit 20 based on the vibration frequency of the determination result of the vibration determination unit 31 and the power setting unit 32 that sets the drive power to be supplied and the supply cycle And an attitude control unit 33 for setting

  The power setting unit 32 uses a current that switches the direction of current flow as a drive power, such as an alternating current, in the forward and reverse directions. The attraction force and the repulsive force with the magnetic poles alternately generated by the electromagnetic solenoid SL are sequentially switched by this driving power, and as a result, in the period synchronized with the frequency of the driving power, in the direction of the vibration axis with the amplitude corresponding to the driving power. Along with this, the vibrating body 10 reciprocates, and this vibration suppresses vibration from an external vibration source.

  Further, by changing the rotational posture of the pair of spring bodies 21 of the resonance unit 20, the spring constant of the plate-like portion 21A in the direction of the vibration axis X of the spring body 21 changes. The resonance frequency changes, and thereby vibration from the outside can be suppressed steplessly.

  In the active vibration isolator of the present invention, the relationship between the rotational posture of the spring body 21 and the resonance frequency of the active vibration isolator is stored in the control unit 30 in the form of table data or the like. Therefore, when the frequency of the external vibration source is detected by the sensor unit 30S, the spring of the resonance unit 20 is obtained so as to obtain a resonance frequency that matches the resonance frequency corresponding to the detected frequency based on the stored data. Control is performed to set the rotational posture of the body 21 and to supply drive power corresponding to the detected phase to the electromagnetic solenoid SL at the detected vibration level at a frequency corresponding to the resonance frequency.

[Second Embodiment]
As shown in FIG. 5, in the second embodiment, the basic configuration for generating vibrations of the main housing 1, the base housing 2, the vibrating body 10, and the like is not different from that of the first embodiment. The configuration is different from that of the first embodiment.

  In other words, a spring body 21 formed by forming a wire such as a piano wire in a coil shape has its spring axis arranged coaxially with the vibration axis X, and its upper end is connected to the lower end of the center rod 13. The fitting body 27 is fitted to the lower end side of the.

  The fitting body 27 has a cylindrical structure in which a spiral groove 27A into which the spring body 21 is fitted, and a spring that can vibrate by rotating the fitting body 27 around the vibration axis X. Since the spring constant changes, the spring constant also changes, and as a result, the resonance frequency can be changed. The fitting body 27 is maintained in a relative positional relationship by the frictional force between the groove 27A and the spring body 21.

  The means for rotating the fitting body 27 is assumed to be an electric motor, but may be provided with a structure for artificially operating.

  In place of such a coil-shaped spring body 21, a rod-shaped spring body 21 is attached to the center rod 13 and the base housing 2 in a posture orthogonal to the vibration axis X, and this rod-shaped spring body is attached. You may comprise so that the pressing member provided in the intermediate position of the body 21 may be moved to a longitudinal direction.

  In this configuration, the pressing member has a through hole through which the rod-shaped spring body 21 is inserted, and is a member having a structure that is slidably supported in the forming direction of the rod-shaped spring 21 with respect to the bottom wall 3 and the base housing 2. It is. The resonance frequency can be changed by adjusting the effective length of the rod-shaped spring body 21 by the sliding movement of the pressing member.

[Third Embodiment]
As shown in FIG. 6, in the third embodiment, the basic configuration for generating vibrations of the main housing 1, the base housing 2, the vibrating body 10, and the like is not different from the first embodiment, and the resonance unit 20 The configuration is different from that of the first embodiment.

  That is, an arm-shaped spring body 21 such as a plate-shaped steel plate is provided through the lower end of the center rod 13 in a posture (horizontal posture) orthogonal to the vibration axis X, and with respect to both ends of the spring body 21. The weight 28 is provided so as to be freely fitted.

  A through hole 28A through which the spring body 21 is inserted is formed in the weight 28, and the weight 28 is maintained in a relative positional relationship by the frictional force between the inner surface of the through hole 28A and the spring body 21. Then, changing the position of the weight 28 also changes the spring constant, and as a result, the resonance frequency can be changed.

  Although it is assumed that an artificial operating force is applied when adjusting the position of the weight 28, a configuration using a driving force of an electric motor may be employed.

Sectional drawing of the active vibration isolator of 1st Embodiment The perspective view which shows the shape of the spring body of 1st Embodiment. The figure which shows the rotation attitude | position of a pair of spring body of 1st Embodiment. 1 is a block circuit diagram of a control system of the active vibration isolator according to the first embodiment. The figure which shows the structure of the spring body of 2nd Embodiment. The figure which shows the structure of the spring body of 3rd Embodiment.

Explanation of symbols

1 Housing (Main housing)
2 Housing (base housing)
DESCRIPTION OF SYMBOLS 10 Excitation body 14 Support spring 20 Resonance unit 21 Spring body 22 Bearing part 23 Interlocking mechanism (gear)
25 Actuator (Electric motor)
27 Fitting body 27A Groove 28 Weight SL Electromagnetic solenoid T Thickness W Width X Vibration axis

Claims (5)

  A vibrating body that reciprocates in the vibration axis direction by magnetism acting from an electromagnetic solenoid is supported by the housing via a support spring, linked to the vibrating body via a linkage portion, and the spring constant can be changed. An active vibration isolator provided with a resonance unit having a possible spring body.   The resonance unit is a rod-shaped spring body having a cross-sectional shape with different width and thickness in the radial direction, and a bearing portion that supports the spring body on the housing so as to be rotatable around an axis in the longitudinal direction. The active vibration isolator according to claim 1, comprising:   A pair of the spring bodies are arranged in a parallel posture at a position sandwiching the vibration axis, and an interlocking mechanism for maintaining the rotational posture of the pair of spring bodies in a symmetric posture across the vibration axis is provided. The active vibration isolator according to claim 2, further comprising an actuator that sets a rotational posture of the spring body around the axis.   2. The active type according to claim 1, wherein the resonance unit includes the spring body formed by forming a wire rod in a coil shape, and a fitting body in which a groove portion capable of adjusting a fitting amount with respect to the spring body is formed. Anti-vibration device.   2. The active vibration isolator according to claim 1, wherein the resonance unit includes the arm-like spring body in a posture orthogonal to the vibration axis, and a weight supported so as to be movable with respect to the spring body.

Images