JP2023087458A - Vibration suppression device - Google Patents

Abstract

To provide a device capable of suppressing the transmission of vibration between members approaching/separating from each other using a rotary inertial body.SOLUTION: A vibration suppression device includes an inertial body 4 to be rotated around an axis running along the vibration direction of a drive unit, and a vibration conversion mechanism 16 for, when the drive unit is vibrated, rotating the inertial body 4 and moving the inertial body 4 forward and backward. A bearing 14 is provided between a holding part 11 for allowing a load in the vibration direction to work on the inertial body 4 and the inertial body 4, and a soft body 24 is provided between an arm 15 having a screw part for rotating the inertial body 4 with the load in the vibration direction on the inertial body 4 and a support body 2 for allowing the relative movement in the other directions than the vibration direction.SELECTED DRAWING: Figure 1

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for suppressing vibration by inertial force of a mass body, and more particularly to a device for suppressing linear vibration such as vertical vibration by using a rotary inertia body.

A device configured to utilize inertial force as a force for suppressing vibration is widely known. is described. Briefly explaining the configuration, the torsional vibration reduction device described in Patent Document 1 has an input-side member connected to the engine and an output-side member connected to the output shaft. A flywheel is connected to a member on the output side thereof via a centrifugal clutch. When a difference in angular acceleration occurs between the input side member and the output side member due to engine torque vibration, a torque corresponding to the difference in angular acceleration and the moment of inertia of the flywheel is generated. acts as The centrifugal clutch is designed to disengage and disconnect the flywheel as the number of revolutions increases. By doing so, the frequency band in which the vibration damping effect can be obtained is automatically set according to the number of revolutions. be done.

JP 2012-225482 A

The torsional vibration reduction device described in Patent Document 1 is a device configured to reduce vibration by torque generated by the difference in angular acceleration. This is limited to systems in which torque oscillates, and cannot be applied to vibration reduction in systems such as engine mounts that vibrate vertically or horizontally. In other words, there is room for developing a new technique to make a rotary inertia body such as a flywheel function more effectively to suppress vibration.

SUMMARY OF THE INVENTION The present invention has been made in view of the above technical problems, and is a device that uses a rotary inertia body to effectively suppress the vibration caused by approaching and separating a drive unit and a support. It is intended to provide

In order to achieve the above objects, the present invention provides a vibration suppressing device that suppresses vibration transmitted between a drive unit that vibrates due to output of power and a support that supports the drive unit. an elastic member for suppressing vibration provided between the drive unit and the support; and the drive unit and the support are rotatable about an axis along the direction of vibration in which the drive unit and the support move toward and away from each other due to vibration. a provided rotational inertia body, a holding section that holds the rotational inertia body in a state of being rotatable about an axis along the vibration direction and restrained in the vibration direction, a male threaded section and a female threaded section, and A feed screw mechanism that rotates the rotational inertia body about the axis by relative movement of the male threaded portion and the female threaded portion in the vibration direction, and either one of the male threaded portion and the female threaded portion is formed. and a vibrating direction in which the drive unit and the support move toward and away from each other by vibration, thereby rotating the rotational inertia body and moving the drive unit and the support toward and away from each other. and a vibration conversion mechanism for moving the rotational inertia body back and forth, the holding portion being provided in one of the drive unit and the support, and the arm portion being provided in the other of the drive unit and the support. is provided, the other of the male threaded portion and the female threaded portion is formed on the rotational inertia body, and between the surfaces of the rotational inertia body and the holding portion facing each other that transmit the load in the vibration direction, the A bearing is provided to reduce frictional force due to relative rotation between the rotary inertia body and the holding portion, and is provided between one of the drive unit and the support and the holding portion, or between the drive unit and the support. and the arm portion, when the drive unit and the support body move relative to each other in a direction different from the vibration direction, the rotation center axis of the rotary inertia body is along the vibration direction. A flexible body is provided to allow relative movement between one of the drive unit and the support and the holding portion or relative movement between the other of the drive unit and the support and the arm so that It is characterized by having

In the present invention, the holding portion includes an annular wall portion formed on one of the drive unit and the support, and the outer diameter of the tip of the rotational inertia body is equal to that of the rotational inertia body in the vibration direction. The tip of the rotary inertia body penetrates through the wall and is held at the tip of the rotary inertia body that penetrates the wall. An opposing fixing portion is attached, and between the surfaces of the wall portion and the central portion of the rotational inertia body in the vibration direction facing each other in the vibration direction, and between the surfaces of the wall portion and the fixing portion facing each other in the vibration direction. The bearing may be provided between the facing surfaces.

In the present invention, the holding portion includes a cylindrical shaft that is connected to one of the drive unit and the support, extends in the vibration direction, and accommodates the rotational inertia body inside. and the inner diameter of the small-diameter portion, which is a portion on one side of the drive unit and the support relative to the rotational inertia body, is formed smaller than the outer diameter of the rotational inertia body, and the tip of the cylindrical shaft and the The bearing may be provided between surfaces of the small diameter portion and the rotational inertia body facing each other in the vibration direction.

In the present invention, the holding portion includes a holding shaft connected to one of the drive unit and the support and extending in the vibration direction, and the rotational inertia body is cylindrical through which the holding shaft passes. and the holding shaft has two fixed portions provided to sandwich the rotational inertia body in the vibration direction, and the two fixed portions and the rotational inertia body face each other in the vibration direction. The bearing may be provided between.

In the present invention, the feed screw mechanism may be configured by a ball screw mechanism in which spherical balls are rotatably arranged inside screw grooves.

In the present invention, the lead angle of the feed screw mechanism may be smaller than 45 degrees.

According to the present invention, when the drive unit or the support vibrates and the two approaches and separates due to vibration, the elastic force of the elastic member provided between the two acts to suppress the vibration. Relative movement toward and away from the support causes rotation of the rotary inertia body by the vibration conversion mechanism. Since the torque corresponding to the angular acceleration and the moment of inertia in that case acts as a reaction force against the force that rotates the rotary inertia body, the torque suppresses the vibration. That is, by rotating the rotary inertia body, it is possible to suppress the linear vibration in which the drive unit and the support are relatively approached and separated from each other.

In addition, since the rotary inertia body is connected to or held by the drive unit and the support by the feed screw mechanism, the rotary inertia body rotates due to vibration and moves back and forth along the central axis of the rotary inertia body. The inertial force caused by this movement and the inertial force caused by the longitudinal movement in the axial direction act as a vibration suppressing force, so that the vibration can be suppressed more effectively.

Furthermore, when the drive unit vibrates in the vibration direction, the rotary inertia body rotates to suppress the vibration, so the rotary inertia body and the holding portion rotate relative to each other. Therefore, by providing a bearing between the opposing surfaces of the rotary inertia body and the holding portion that transmit the load in the vibrating direction, the rotary motion of the rotary inertia body can be performed smoothly. In addition, by providing a flexible body that allows relative movement between one of the drive unit and the support and the holding portion or relative movement between the other of the drive unit and the support and the arm, the drive unit is added to the vibration direction. When the drive unit and the support body move relative to each other due to vibration in another direction, the inclination of the rotation center axis of the rotary inertia body and the axis of the arm can be suppressed, and the bearing and the rotary inertia body It is possible to suppress an increase in the resistance force due to uneven contact. As a result, it is possible to suppress the deterioration of the vibration reduction effect associated with the rotary motion of the rotary inertia body.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram for demonstrating an example of embodiment of this invention. It is an explanatory view showing the force received by the rotor, which is the rotational inertia body. FIG. 10 is a diagram for explaining a vibration reduction effect by providing a thrust bearing; It is a figure for demonstrating the vibration reduction effect by providing rubber|gum. FIG. 4 is a schematic diagram for explaining another embodiment of the present invention; FIG. 4 is a schematic diagram for explaining still another embodiment of the present invention;

The present invention will be described based on embodiments shown in the drawings. It should be noted that the embodiment described below is merely an example when the present invention is embodied, and does not limit the present invention.

An embodiment of the invention is shown schematically in FIG. The example shown here is between a drive unit 1 that vibrates as power is output from an internal combustion engine or the like, and a support body (hereinafter referred to as a body) 2 such as a body that supports the drive unit 1. This is an example configured to suppress the vibration of An elastic member 3 for suppressing vibration is provided between the drive unit 1 and the body 2 . The elastic member 3 is composed mainly of rubber or a spring, and may be a conventionally known engine mount.

An inertial mass that generates an inertial force for suppressing vibration is provided between the drive unit 1 and the body 2 . This inertial mass body is a rotary inertia body 4 that performs translational motion accompanied by rotary motion, and the rotary inertia body 4 moves in a direction in which the drive unit 1 and the body 2 approach and separate (hereinafter referred to as a vibration direction). is held by a vibration converting mechanism that converts the force of the rotary inertia body 4 into translational motion accompanied by rotary motion. In the example shown in FIG. 1, a rotary inertia body (hereinafter referred to as a rotor) 4 is held so as to rotate about an axis along the vibrating direction and move back and forth in the vibrating direction.

In the example shown here, the rotor 4 includes a cylindrical main shaft portion 5 formed with a large diameter, and an intermediate portion extending from the end portion of the main shaft portion 5 on the drive unit 1 side and having a diameter smaller than that of the main shaft portion 5 . A shaft portion 6, a first holding shaft portion 7 extending from an end portion of the intermediate shaft portion 6 on the drive unit 1 side and having a diameter smaller than that of the intermediate shaft portion 6, and an end portion of the main shaft portion 5 on the body 2 side. The first holding shaft portion 7 is rotatably held by the drive unit 1 .

The drive unit 1 is formed with a recess 9 into which a part of the intermediate shaft portion 6 and the first holding shaft portion 7 are inserted. A retaining wall 11 having a through hole 10 through which is provided. This holding wall 11 corresponds to the "wall" in the embodiment of the present invention, is inserted from the opening of the recess 9 to a predetermined position, and is held by a position regulating member 12 such as an E-ring or snap ring. Sideways movement is restricted. That is, the retaining wall 11 is integrated with the drive unit 1 .

The first holding shaft portion 7 is inserted into the through hole 10 of the holding wall 11, and a nut 13 corresponding to the "fixing portion" in the embodiment of the present invention is provided on the portion protruding from the holding wall 11 toward the bottom surface of the recess 9. is tightened. That is, the retaining wall 11 is sandwiched between the nut 13 and the intermediate shaft portion 6 . While the rotor 4 rotates, the retaining wall 11 is integrated with the drive unit 1, so that the nut 13 and the retaining wall 11 rotate relative to each other. 6 and the holding wall 11 rotate relative to each other. Therefore, the thrust bearing 14 is provided to reduce the frictional resistance between the nut 13 or the intermediate shaft portion 6 and the retaining wall 11 . That is, the rotor 4 is held by the holding wall 11 so as to be rotatable about the axis along the vibrating direction and restrained in the vibrating direction. The thrust bearing 14 corresponds to the "bearing" in the embodiment of the invention, and the holding wall 11 corresponds to the "holding part" in the embodiment of the invention.

The second holding shaft portion 8 is held by a cylindrical shaft 15 attached to the end surface of the body 2 so as to be rotatable and to rotate about the central axis of the second holding shaft portion 8 . Specifically, the cylindrical shaft 15 and the second holding shaft portion 8 constitute a feed screw mechanism 16 . The feed screw mechanism 16 is configured to convert force in the vibrating direction of the drive unit 1 and the body 2 into rotational motion of the rotor 4 . Therefore, in order to suppress the reduction in the efficiency of converting the force in the vibration direction into the force in the rotation direction, that is, to minimize the frictional force in the feed screw mechanism 16, the example shown in FIG. A ball screw mechanism is used.

Specifically, the outer peripheral portion of the second holding shaft portion 8 is formed with a thread groove 17 that is a spiral groove (recess), and therefore the outer peripheral portion of the second holding shaft portion 8 serves as a male thread portion 18 . ing. A thread groove 19 corresponding to the thread groove 17 is formed on the inner peripheral surface of the cylindrical shaft 15 that accommodates the second holding shaft portion 8. Therefore, the inner peripheral surface of the cylindrical shaft 15 is a female thread. It is part 20. These thread grooves 17 and 19 are so-called spherical grooves having an arc-shaped cross section, and a large number of spherical balls 21 such as steel balls are accommodated in these thread grooves 17 and 19 so as to be able to roll. That is, the male threaded portion 18 and the female threaded portion 20 are engaged with each other via the balls 21 . It should be noted that the cylindrical shaft 15 corresponds to the "arm portion" in the embodiment of the present invention.

A flange portion 22 is formed at the end portion of the cylindrical shaft 15 on the side of the body 2, and a plurality of through holes are formed in the flange portion 22 at predetermined intervals in the circumferential direction of the flange portion 22. A hole 23 is formed. A soft body is sandwiched between the flange portion 22 and the body 2 . This soft body allows the cylindrical shaft 15 and the body 2 to move relative to each other in directions different from the vibrating direction, such as the vertical direction and the depth direction on the paper surface. In other words, when the body 2 moves relative to the drive unit 1 in a direction different from the vibration direction, the center axes of the holding wall 11 holding the rotor 4 and the cylindrical shaft 15 are different, that is, the rotor 4 rotates. This suppresses the inclination of the center axis with respect to the axis along the vibration direction.

In the example shown in FIG. 1, it is constituted by rubber 24 formed in an annular shape. That is, when the drive unit 1 moves relative to the body 2 in a direction different from the vibration direction, the relative position between the body 2 and the cylindrical shaft 15 changes due to bending of the rubber 24 or the like. . That is, the rigidity of the cylindrical shaft 15 and the body 2 in directions other than the vibration direction is weaker than the rigidity of the drive unit 1 and the rotor 4 in directions other than the vibration direction.

A through hole 25 is formed in the rubber 24 at the same position as the through hole 23 formed in the flange portion 22 . It is configured to be attached to the body 2 in a state in which the flange portion 22 and the rubber 24 are overlapped. That is, the body 2 is provided with internal threads 26 at the same positions as the through holes 23 and 25 formed in the flange portion 22 and the rubber 24 . A bolt 27 is tightened and fixed to 26 . A concave portion 28 is formed to prevent the tip of the second holding shaft portion 8 from coming into contact with the body 2 when the second holding shaft portion 8 approaches the body 2 side.

Next, the vibration reduction effect of the device configured as described above will be described. The force that the rotor 4 (more specifically, the second holding shaft portion 8) receives due to the vibration of the drive unit 1 is as shown in FIG. be.

2, _f1 is the force received from the drive unit 1, _f2 is the force received from the body 2, _f2x is the axial component of the force received from the body 2, and _f2y is the force received from the body 2. Of these, r is the force point radius of the second holding shaft portion 8 , and p is the thread pitch (lead) in the feed screw mechanism 16 . In the above equation of motion, m is the mass of the rotor 4, x _{3 two} dots (d ² x ₃ /dt ² ) is the acceleration of the center of gravity of the rotor 4, I is the moment of inertia of the rotor 4, and θ _{3 two} dots (d ² θ ₃ /dt ² ) indicate the angular acceleration of the rotor 4 around the center of gravity.

なお、上記の式で、ｘ_１ツードット（ｄ^２ｘ_１／ｄｔ^２）は駆動ユニット１の加速度、ｘ_２ツードット（ｄ^２ｘ_２／ｄｔ^２）はボディ２の加速度をそれぞれ示す。すなわち、駆動ユニット１とボディ２とは接近および離隔することができるから、それらの振動方向での変位量ｘ_１，ｘ_２の差およびそれに伴う加速度の差が、ロータ４の回転および角加速度として現れる。また、駆動ユニット１とロータ４とは振動方向においては一体となっているので、それらの振動方向での加速度は等しい。さらに、ボディ２から受ける力ｆ_２の軸線方向成分ｆ_２ｘおよび回転周方向成分ｆ_２ｙとの比率は、ロータ４（具体的には、第２保持軸部８）の周長２πｒとピッチｐとの比率と等しい。 Further, the relational expressions of acceleration and angular acceleration on the rotor 4 are as follows.

In the above formula, x _{1 two} dots (d ² x ₁ /dt ² ) indicates acceleration of drive unit 1 and x _{2 two} dots (d ² x ₂ /dt ² ) indicates acceleration of body 2 . That is, since the drive unit 1 and the body 2 can move toward and away from each other, the difference in the displacement amounts x ₁ and x ₂ between them in the direction of vibration and the difference in the accompaniment of the acceleration are the rotation and angular acceleration of the rotor 4. appear. Further, since the drive unit 1 and the rotor 4 are integrated in the vibrating direction, their accelerations in the vibrating direction are the same. Furthermore, the ratio between the axial component _f2x and the rotation circumferential component _f2y of the force _f2 received from the body 2 is determined by the circumferential length 2πr and the pitch p of the rotor 4 (specifically, the second holding shaft portion 8). equal to the ratio of

Therefore, the force f ₁ that the rotor 4 receives from the drive unit 1 and the force f _2x in the so-called vibration direction that the rotor 4 receives from the body 2 are as follows.

となるから、駆動ユニット１が受ける力Ｆｅ、およびボディ２が受ける力Ｆｂは、それぞれ下記の式で表される。

なお、ｋは弾性部材３のばね定数である。 Assuming a simple harmonic motion with an angular velocity ω with respect to the displacement amounts x ₁ and x ₂ of the drive unit 1 and the body 2 in the so-called vibration directions,

Therefore, the force Fe applied to the drive unit 1 and the force Fb applied to the body 2 are expressed by the following equations.

Note that k is the spring constant of the elastic member 3 .

となる。なお、ｘ_ｅは駆動ユニット１の変位量、ｘ_ｂはボディ２の変位量である。 Transforming this into a determinant, we get

becomes. Note that _xe is the displacement amount of the drive unit 1 and _xb is the displacement amount of the body 2 .

The first term in braces in the determinant above represents the inertial force associated with the translational motion of the rotor 4 . As is known from the fact that the lower rows of the matrix are both "0", the force received by the body 2 is zero. That is, the force vibrating the body 2 is eliminated. This is because the rotor 4 is integrated in the drive unit 1 in the vibration direction. Since the force that cannot be offset by the inertial force increases in proportion to the mass m of the rotor 4, it is preferable that the mass m of the rotor 4 is as small as possible.

The second term in the braces in the determinant above indicates the relative displacement between the drive unit 1 and the body 2, and if the value in the braces that is the coefficient of the matrix becomes zero , the force transmitted by the elastic member 3 is canceled by the inertial force of the rotor 4, and the transmission of vibration to the body 2 can be avoided or reduced. That is, by appropriately setting the moment of inertia I of the rotor 4 and the pitch (or lead) p of the feed screw mechanism 16 in relation to the spring constant of the elastic member 3, it is possible to obtain a vibration at a predetermined angular velocity ω or in the vicinity thereof. can be reduced to zero or a small value, resulting in reduced vibration.

As described above, according to the above-described apparatus as the first embodiment of the present invention, the rotor 4 is rotated and linearly rotated by utilizing the force generated by the vibration of the drive unit 1 and the body 2 in the direction toward and away from each other. By moving, i.e., by translating with rotational movement, vibration can be reduced by its inertial force.

Here, the relationship between the lead angle of the feed screw mechanism 16, that is, the pitch p, and the circumferential length of the rotor 4 (more specifically, the second holding shaft portion 8) will be described. The moment of inertia I when the formula as the coefficient of the second term in the curly braces in the determinant described above is "0" is
4π ² Iω ² /p ² =k
I=(kd ² /4ω ² )*(p/πd) ²
is. Here, ω is the input angular velocity and d is the diameter of the second holding shaft portion 8 . The moment of inertia I represented by this formula is the moment of inertia that can cancel the spring force with the spring constant k at a predetermined input angular velocity ω. Therefore, if the pitch (lead) p is smaller than the circumference .pi.d, their ratio becomes smaller than "1", so that the force transmitted through the elastic member 3 can be effectively canceled. If the relationship between the pitch (lead) p and the circumference .pi.d is represented by a lead angle, the lead angle is preferably smaller than 45 degrees.

As described above, the vibration damping device of the present invention reduces the vibration by the inertial force of the rotor 4 caused by the translational motion accompanied by the rotational motion. When the resistance acts, the vibration reduction effect decreases.

As shown in FIG. 1, one end of the rotor 4 moves together with the drive unit 1 in the vibrating direction, and the other end is held on the cylindrical shaft 15 by the feed screw mechanism 16. When a reaction force acts against the translational motion of the rotor 4, it is converted into a load in the direction of rotating the rotor 4, so that the translational motion of the rotor 4 is affected only slightly. On the other hand, since the contact portion between the drive unit 1 and the rotor 4 relatively rotates while a load acts in the vibration direction, the frictional resistance at the contact portion has a large effect on the rotational motion of the rotor 4 . In other words, the smooth rotation of the rotor 4 can absorb the relative movement in the vibration direction between the drive unit 1 and the body 2 , thereby reducing the vibration transmitted from the rotor 4 to the body 2 .

Therefore, when the frictional resistance in the rotational direction at the contact portion between the drive unit 1 and the rotor 4 is large, the relative movement between the drive unit 1 and the body 2 cannot be sufficiently absorbed as the rotational motion of the rotor 4. A load (kinetic energy) in the vibration direction that cannot be absorbed as the rotational motion of the rotor 4 is transmitted to the body 2 .

Therefore, in the example shown in FIG. 1, a thrust bearing 14 is provided at the contact portion between the drive unit 1 and the rotor 4 . More specifically, when the drive unit 1 vibrates in the vibration direction, the load in the vibration direction is transmitted from the thrust bearing 14 provided in the drive unit 1 to the intermediate shaft portion 6 and the nut 13. .

FIG. 3 shows the result of verifying the vibration reduction effect according to the magnitude of the frictional force between the drive unit 1 and the rotor 4. As shown in FIG. In this verification experiment, the drive unit 1 was driven in the usual manner, and the load in the vibration direction of the drive unit 1 and the acceleration in the vibration direction of the body 2 were measured. Calculated. The vertical axis in FIG. 3 represents inertance (the acceleration A (A/F) of the body 2 in the vibration direction with respect to the load F of the drive unit 1 in the vibration direction), and the horizontal axis represents its frequency. 3 indicates the inertance when only the elastic member 3 is provided without the rotor 4, and the dashed line indicates the connection between the drive unit 1 and the rotor 4 without providing the thrust bearing 14. The solid line shows the inertance when the vibration reduction device shown in FIG. 1 is used, ie when the friction force in the rotation direction of the rotor 4 is small. There is.

By providing the rotor 4 as shown in FIG. 3, the vibration transmitted to the body 2 can be reduced. Further, in a frequency band fr1 within a predetermined range centering on a predetermined frequency fr, vibration is greatly reduced when the frictional force in the rotational direction of the rotor 4 is small compared to when the frictional force in the rotational direction of the rotor 4 is large. It is

On the other hand, the drive unit 1 vibrates not only in the direction toward and away from the body 2, but also in the direction orthogonal to the vibration direction. Specifically, the drive unit 1 vibrates so that the drive unit 1 and the body 2 move relative to each other in the vertical direction in FIG. 1 and in the depth direction of the paper surface. When the drive unit 1 vibrates in this way, the rotation axis of the rotor 4 is inclined with respect to the horizontal direction in FIG. There is a possibility that the rotor 4 cannot rotate smoothly due to uneven contact or the like. Therefore, the vibration damping device of the present invention is constructed such that the cylindrical shaft 15 and the body 2 are connected via the rubber 24 as shown in FIG. That is, when the drive unit 1 and the body 2 move relative to each other in the vertical direction or in the depth direction of the paper surface, the cylindrical shaft 15 is configured to move relative to the body 2 by the amount of the relative movement. ing.

FIG. 4 shows the result of verifying the vibration reduction effect according to the presence or absence of the rubber 24 that absorbs movement of the drive unit 1 and the body 2 in directions other than the vibration direction. In this verification experiment, similarly to the verification shown in FIG. The inertance for each frequency was calculated from the measurement results. The vertical axis in FIG. 4 represents inertance, and the horizontal axis represents its frequency. 4 indicates the inertance when only the elastic member 3 is provided without the rotor 4, and the dashed line indicates the inertance when the vibration reduction device without the rubber 24 in FIG. 1 is used. The inertance is shown, and the solid line shows the inertance when the vibration reduction device shown in FIG. 1 is used.

As shown in FIG. 4, in the frequency band fr2 within a predetermined range, the vibration reduction effect in which the rubber 24 is not provided is slightly greater, but in frequencies above the frequency band fr2, the rubber 24 is provided. The vibration reduction device with the rubber 24 has a greater vibration reduction effect as the frequency increases than the vibration reduction device without the rubber 24 .

As described above, by providing the thrust bearing 14 that holds the rotor 4 rotatably and reduces the frictional resistance of the portion that transmits the load in the vibration direction (thrust direction) to the rotor 4, the rotational motion of the rotor 4 is smooth. can be done. Further, by providing the soft body 24 that absorbs the relative movement of the drive unit 1 and the body 2 in a direction other than the vibration direction, even if the drive unit 1 moves in a direction other than the vibration direction with respect to the body 2, Also, since the soft body 24 is deformed so that the rotation center axis of the rotor 4 becomes the axis along the vibration direction, it is possible to suppress the rotor 4 from tilting with respect to the thrust bearing 14 . By interposing a soft rubber 24 between the cylindrical shaft 15 and the body 2, the cylindrical shaft 15 is connected to the body 2 with respect to the portion that holds the rotor 4 on the drive unit 1 side. This is because the parts can easily move in directions other than the vibration direction. As a result, it is possible to suppress an increase in the resistance force due to uneven contact between the thrust bearing 14 and the rotor 4, and even if the drive unit 1 vibrates in combination in the direction of vibration and in a direction different from the direction of vibration. Even if there is, the rotor 4 can be rotated smoothly. In other words, the thrust bearing 14 can function as intended to reduce friction, thereby suppressing a decrease in the effect of reducing vibration accompanying the rotary motion of the rotor 4 .

In the vibration reduction device according to the embodiment of the present invention, either one of the drive unit 1 and the body 2 and the rotor 4 can move together in the vibration direction, and the drive unit 1 and the body 2 can move together. and a bearing 14 configured to absorb the relative movement of the rotor 4 by the rotation of the rotor 4 and reduce the frictional resistance of the portion that transmits the load in the vibration direction to the rotor 4; It is only necessary to include a soft body 24 that allows the relative movement in the direction and suppresses the tilting of the axis of the rotor 4 .

FIG. 5 shows an example of a vibration reduction device in which the body 2 and the rotor 4 are integrally configured to move in the vibration direction. In the example shown in FIG. 5 , a holding shaft 29 extending from the drive unit 1 toward the body 2 is integrated with the drive unit 1 . The rotor 4 is connected to the holding shaft 29 via the feed screw mechanism 16 . Specifically, a spiral thread groove 30 is formed on the outer peripheral surface of the holding shaft 29 in the same manner as the second holding shaft portion 8 described above. Further, the rotor 4 shown in FIG. 5 is formed in a cylindrical shape, and a thread groove 31 corresponding to the thread groove 30 is formed on the inner surface thereof. Balls 21 are rotatably accommodated in these screw grooves 30 and 31 . The holding shaft 29 described above corresponds to the "arm section" in the embodiment of the present invention.

The rotor 4 is provided so as to be integrated with the body 2 in the vibrating direction. Specifically, a cylindrical shaft 32 corresponding to a "holding portion" in the embodiment of the present invention is formed from the side surface of the body 2 to the drive unit 1 side, and the rotor 4 is accommodated inside the cylindrical shaft 32. ing. That is, the cylindrical shaft 32 is formed to the drive unit 1 side from the rotor 4 . The diameter of the opening at the tip of the cylindrical shaft 32 is formed smaller than the outer diameter of the rotor 4 . That is, when a load acts on the rotor 4 in a direction away from the body 2, the movement of the rotor 4 toward the drive unit 1 is restricted. The cylindrical shaft 32 is formed by separately forming a cylindrical main portion and a tip portion attached to the tip of the main portion and having an inner diameter smaller than the opening diameter of the main portion. The tip may be configured to be fixed to the main portion so as to close the open end.

Further, a small-diameter portion 33 having an inner diameter smaller than the outer diameter of the rotor is formed in a portion closer to the body 2 than the rotor 4 in the axial direction of the cylindrical shaft 32 . That is, it is configured to restrict the movement of the rotor 4 toward the body 2 when a load acts on the rotor 4 in a direction approaching the body 2 . A bushing 34 is inserted between the outer peripheral surface of the rotor 4 and the inner peripheral surface of the cylindrical shaft 32, and between the end surface of the rotor 4, the tip of the cylindrical shaft 32, and the surfaces of the small diameter portion 33 facing each other in the vibration direction. is provided with an annular thrust bearing 35 .

As in the example shown in FIG. 1, the cylindrical shaft 32 has a flange portion 36 formed at its tip on the side of the body 2, and a soft rubber 24 is provided between the flange portion 36 and the body 2. It is sandwiched between them. Note that the rubber 24 may be interposed between the drive unit 1 and the holding shaft 29 .

In the vibration reducing device configured in this manner, when the drive unit 1 vibrates to approach or separate from the body 2, the relative movement amount of the drive unit 1 and the body 2 in the vibrating direction is controlled by the rotation of the rotor 4. Vibration transmitted from the drive unit 1 to the body 2 by its rotational motion can be reduced. In addition, by providing a thrust bearing 35 between the portion that applies an axial load to the rotor 4, that is, between the rotor 4 and the tip of the cylindrical shaft 32 and the small-diameter portion 33, friction against the rotational motion of the rotor 4 is achieved. It is possible to reduce the generation of force, and it is possible to suppress the reduction of the vibration reduction effect. Furthermore, by interposing a soft material such as rubber 24 between the cylindrical shaft 32 and the body 2, even if the drive unit 1 and the body 2 move relative to each other in the direction perpendicular to the central axis of the rotor 4, Also, it is possible to suppress uneven contact between the rotor 4 and the portion that applies the load along the central axis to the rotor 4 . As a result, even if the drive unit 1 vibrates in combination in the vibrating direction and in a direction different from the vibrating direction, the rotor 4 can be smoothly rotated, and the vibration reduction effect associated with the rotational motion of the rotor 4 can be achieved. can be improved.

FIG. 6 shows an example of a vibration damping device in which a holding shaft 29 is integrated with the drive unit 1 and a load (thrust load) in the vibrating direction is transmitted from the holding shaft 29 to the rotor 4 . In the example shown in FIG. 6 , a holding shaft 29 extending from the drive unit 1 toward the body 2 is integrated with the drive unit 1 . A cylindrical rotor 4 is fitted to the tip of the holding shaft 29 . The rotor 4 is restrained with respect to the holding shaft 29 so as not to relatively move in the axial direction (vibration direction) of the holding shaft 29 . That is, flange portions 37 corresponding to "fixed portions" in the embodiments of the present invention are provided at two locations of the holding shaft 29 sandwiching the rotor 4, and the flange portions 37 prevent the rotor 4 from moving in the axial direction. It is designed to regulate. These two flange portions 37 may be formed integrally with the holding shaft 29, or may be so-called retaining ring members such as C-rings and E-rings.

A spiral thread groove 38 is formed on the outer peripheral surface of the rotor 4, and a thread groove 19 corresponding to the thread groove 38 is formed on the inner surface of the cylindrical shaft 15 configured in the same manner as the example shown in FIG. ing. Balls 21 are rotatably accommodated in these screw grooves 38 and 19 . That is, the rotor 4 is held by the cylindrical shaft 15 via the feed screw mechanism 16 . A bushing 39 is inserted between the rotor 4 and the holding shaft 29, and a thrust bearing 40 is provided between the surfaces of the rotor 4 and the flange portion 37 facing each other in the vibration direction. . Other configurations are the same as those shown in FIG. 1, and are given the same reference numerals.

In the vibration reducing device configured in this manner, when the drive unit 1 vibrates to approach or separate from the body 2, the relative movement amount of the drive unit 1 and the body 2 in the vibrating direction is controlled by the rotation of the rotor 4. Vibration transmitted from the drive unit 1 to the body 2 by its rotational motion can be reduced. Further, by providing a thrust bearing 40 at a portion that applies an axial load to the rotor 4, that is, between the rotor 4 and each flange portion 37, a frictional force against the rotational motion of the rotor 4 is generated. It is possible to suppress the reduction of the vibration reduction effect. Furthermore, by interposing a soft material such as rubber 24 between the cylindrical shaft 15 and the body 2, even if the drive unit 1 and the body 2 move relative to each other in a direction perpendicular to the central axis of the rotor 4, Also, it is possible to suppress uneven contact between the rotor 4 and the portion that applies the load along the central axis to the rotor 4 . As a result, even if the drive unit 1 vibrates in combination in the vibrating direction and in a direction different from the vibrating direction, the rotor 4 can be smoothly rotated, and the vibration reduction effect associated with the rotational motion of the rotor 4 can be achieved. can be improved.

In the present invention, the configuration shown in each figure is so-called left-right reversed, such as connecting the cylindrical shafts 15 and 32 described above to the drive unit 1, and providing the holding wall 11 for holding the rotor 4 and the holding shaft 29 in the body 2. may be configured as follows.

Reference Signs List 1 drive unit 2 body 3 elastic member 4 rotor 5 main shaft 6 intermediate shaft 7, 8 holding shaft 11 holding wall 12 position regulating member 13 nut 14, 35, 40 thrust bearing 15, 32 cylindrical shaft 16 feed screw mechanism 17, 19, 30, 31, 38 thread groove 18 male threaded portion 20 female threaded portion 21 ball 22, 36, 37 flange portion 24 rubber 29 holding shaft 33 small diameter portion 34, 39 bush

Claims (6)

A vibration suppressing device for suppressing vibration transmitted between a drive unit that vibrates due to power output and a support that supports the drive unit,
an elastic member for suppressing vibration provided between the drive unit and the support;
a rotational inertia body rotatable about an axis along a vibration direction in which the drive unit and the support move toward and away from each other by vibration;
a holding portion for holding the rotational inertia body in a state of being rotatable about an axis along the vibrating direction and constrained in the vibrating direction; and a feed screw mechanism that rotates the rotary inertia body around the axis by relative movement of the internal thread and the internal thread, and an arm formed with either the external thread or the internal thread. and moving the rotary inertia body back and forth in the vibrating direction in which the drive unit and the support body move toward and away from each other by vibration, thereby rotating the rotary inertia body and moving the drive unit and the support body toward and away from each other. Equipped with a vibration conversion mechanism that allows
The holding portion is provided on one of the drive unit and the support,
The arm portion is provided on the other of the drive unit and the support,
the other of the male threaded portion and the female threaded portion is formed on the rotational inertia body;
A bearing for reducing frictional force caused by relative rotation between the rotary inertia body and the holding part is provided between the surfaces of the rotary inertia body and the holding part facing each other and transmitting the load in the vibration direction. ,
Between one of the drive unit and the support and the holding portion, or between the other of the drive unit and the support and the arm, the drive unit and the support are arranged in the vibration direction. Relative movement between one of the drive unit and the support body and the holding part so that the rotation center axis of the rotational inertia body becomes the axis along the vibration direction when relative movement is performed in a direction different from the A vibration suppressing device, comprising: a soft body that allows relative movement between the arm and the other of the drive unit and the support. The vibration suppressing device according to claim 1,
the holding portion includes an annular wall formed on one of the drive unit and the support;
the outer diameter of the tip of the rotational inertia body is formed to be smaller than the outer diameter of the central portion of the rotational inertia body in the vibration direction;
the tip of the rotational inertia body is held through the wall,
A fixing part facing the side surface of the wall is attached to the tip of the rotational inertia body penetrating the wall,
Between the surfaces of the wall portion and the central portion of the rotational inertia body in the vibration direction facing each other in the vibration direction, and between the surfaces of the wall portion and the fixed portion facing each other in the vibration direction, the bearing A vibration suppressing device characterized by being provided with. The vibration reduction device according to claim 1,
the holding part includes a cylindrical shaft connected to one of the drive unit and the support, extending in the vibration direction, and housing the rotational inertia body inside;
The inner diameter of the tip of the cylindrical shaft and the inner diameter of the small-diameter portion, which is a portion on one side of the drive unit and the support relative to the rotational inertia body, are formed to be smaller than the outer diameter of the rotational inertia body,
A vibration suppressing device, wherein the bearing is provided between the surfaces of the distal end of the cylindrical shaft and the small diameter portion and the rotational inertia body facing each other in the vibration direction. The vibration suppressing device according to claim 1,
the holding portion includes a holding shaft connected to one of the drive unit and the support and extending in the vibration direction;
The rotational inertia body is formed in a cylindrical shape through which the holding shaft passes,
The holding shaft has two fixed portions that sandwich the rotational inertia body in the vibration direction,
The vibration suppressing device, wherein the bearing is provided between the surfaces of the two fixed portions and the rotational inertia body facing each other in the vibration direction. The vibration suppressing device according to any one of claims 1 to 4,
A vibration suppressing device according to claim 1, wherein the feed screw mechanism comprises a ball screw mechanism in which spherical balls are rotatably arranged inside screw grooves. In the vibration suppression device according to any one of claims 1 to 5,
A vibration suppressing device, wherein a lead angle of the feed screw mechanism is smaller than 45 degrees.

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