Vibration suppression device

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

[Technical field]

[0001] The present invention relates to a device for suppressing vibrations by the inertial force of a mass body, and more particularly to a device for suppressing linear vibrations such as up-and-down vibrations by a rotating inertial body. [Background technology]

[0002] Devices that utilize inertial force as a force for suppressing vibration are widely known. For example, Patent Document 1 describes a device that reduces the vibration of torque output by an internal combustion engine (engine) using a flywheel. To briefly explain 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 connected via a buffer member such as a spring damper, and a flywheel is connected to the output side member via a centrifugal clutch. When a difference in angular acceleration occurs between the input side member and the output side member due to vibration of the engine torque, a torque corresponding to the difference in angular acceleration and the moment of inertia of the flywheel is generated, which acts as a so-called vibration damping torque that reduces vibration. The centrifugal clutch is configured to be released and separate the flywheel as the rotation speed increases, and by doing so, the frequency band in which the vibration damping effect is obtained is automatically set according to the rotation speed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-225482 A Summary of the Invention [Problem to be solved by the invention]

[0004] The torsional vibration reduction device described in the above Patent Document 1 is a device configured to reduce vibration by torque generated by differences in angular acceleration, and therefore the vibration systems to which it can be applied are limited to systems in which the torque of a rotating member vibrates, and it cannot be applied to vibration reduction in systems that vibrate vertically or horizontally, such as engine mounts. In other words, there was room for the development of new technology to make rotating inertia bodies such as flywheels function more effectively to suppress vibration.

[0005] The present invention has been made in consideration of the above-mentioned technical problems, and aims to provide a device that can effectively suppress vibrations caused by the approaching and separating of a drive unit and a support by using a rotating inertia body. [Means for solving the problem]

[0007] This issue In order to achieve the above object, the present invention provides a vibration suppression device that suppresses vibrations transmitted between a drive unit that vibrates in response to the output of power and a support supporting the drive unit, the vibration suppression device comprising: an elastic member for vibration suppression provided between the drive unit and the support; a rotary inertia body provided rotatably about an axis along a vibration direction in which the drive unit and the support approach and separate from each other due to vibration; a holding section that holds the rotary inertia body in a state in which the rotary inertia body is rotatable about an axis along the vibration direction but is constrained in the vibration direction; a feed screw mechanism that has a male threaded section and a female threaded section and rotates the rotary inertia body about the axis by relative movement of the male threaded section and the female threaded section in the vibration direction; and an arm section on which one of the male threaded section and the female threaded section is formed, the rotary inertia body being rotated and the drive unit and the support approach and separate from each other due to vibration. a vibration conversion mechanism for moving the rotary inertia body back and forth in a vibration direction separating the rotary inertia body, 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 thread portion and the female thread portion is formed on the rotary inertia body, a bearing is provided between opposing surfaces of the rotary inertia body and the holding portion which transmit a load in the vibration direction, the bearing reducing a frictional force caused by the relative rotation of the rotary inertia body and the holding portion is provided, and a soft body is provided between the 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 portion, the soft body allowing a relative movement between the 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 portion, such that a rotation center axis of the rotary inertia body becomes an axis along the vibration direction when the drive unit and the support move relatively in a direction different from the vibration direction, The holding portion includes an annular wall portion formed on one of the drive unit and the support, the outer diameter of the tip of the rotary inertia body is formed smaller than the outer diameter of a central portion of the rotary inertia body in the vibration direction, the tip of the rotary inertia body is held by penetrating the wall portion, a fixing portion facing a side surface of the wall portion is attached to the tip of the rotary inertia body that has penetrated the wall portion, and the bearings are provided between a surface where the wall portion and the central portion of the rotary inertia body in the vibration direction face each other in the vibration direction, and between a surface where the wall portion and the fixing portion face each other in the vibration direction. It is characterized by the presence of

[0008] This issue The present invention relates to a vibration suppression device that suppresses vibrations transmitted between a drive unit that vibrates in response to power output and a support that supports the drive unit, the vibration suppression device comprising: an elastic member for vibration suppression provided between the drive unit and the support; a rotary inertia body provided rotatably about an axis along a vibration direction in which the drive unit and the support approach and separate from each other due to vibration; a holding section that holds the rotary inertia body in a state in which the rotary inertia body is rotatable about an axis along the vibration direction but is constrained in the vibration direction; a feed screw mechanism that has a male threaded section and a female threaded section and rotates the rotary inertia body about the axis by relative movement of the male threaded section and the female threaded section in the vibration direction; and an arm section on which one of the male threaded section and the female threaded section is formed, and the drive unit and the support approach and separate from each other due to vibration, the rotary inertia body is rotated and the drive unit and the support are moved toward and away from each other due to vibration, the feed screw mechanism having an elastic member for vibration suppression provided between the drive unit and the support; a vibration conversion mechanism for moving the rotary inertia body back and forth on the support member; the holding portion is provided on one of the drive unit and the support member, the arm portion is provided on the other of the drive unit and the support member, the other of the male thread portion and the female thread portion is formed on the rotary inertia body, a bearing is provided between opposing surfaces of the rotary inertia body and the holding portion that transmit a load in the vibration direction, the bearing reducing a frictional force caused by the relative rotation of the rotary inertia body and the holding portion is provided, and a soft body is provided between the one of the drive unit and the support member and the holding portion, or between the other of the drive unit and the support member and the arm portion, the soft body allowing a relative movement between the one of the drive unit and the support member and the holding portion or between the other of the drive unit and the support member and the arm portion such that a rotation center axis of the rotary inertia body becomes an axis along the vibration direction when the drive unit and the support move relatively in a direction different from the vibration direction; 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 houses the rotary inertia body inside, the inner diameter of the tip of the cylindrical shaft and the inner diameter of a small diameter portion that is a portion on one side of the drive unit and the support body relative to the rotary inertia body are formed smaller than the outer diameter of the rotary inertia body, and the bearing is provided between the tip of the cylindrical shaft, the small diameter portion, and the rotary inertia body, which face each other in the vibration direction. It is characterized by the presence of

[0009] This issue The present invention relates to a vibration suppression device that suppresses vibrations transmitted between a drive unit that vibrates in response to power output and a support that supports the drive unit, the vibration suppression device comprising: an elastic member for vibration suppression provided between the drive unit and the support; a rotary inertia body provided rotatably about an axis along a vibration direction in which the drive unit and the support approach and separate from each other due to vibration; a holding section that holds the rotary inertia body in a state in which the rotary inertia body is rotatable about an axis along the vibration direction but is constrained in the vibration direction; a feed screw mechanism that has a male threaded section and a female threaded section and rotates the rotary inertia body about the axis by relative movement of the male threaded section and the female threaded section in the vibration direction; and an arm section on which one of the male threaded section and the female threaded section is formed, and the drive unit and the support approach and separate from each other due to vibration, the rotary inertia body is rotated and the drive unit and the support are moved toward and away from each other due to vibration, the feed screw mechanism having an elastic member for vibration suppression provided between the drive unit and the support; a vibration conversion mechanism for moving the rotary inertia body back and forth on the support member; the holding portion is provided on one of the drive unit and the support member, the arm portion is provided on the other of the drive unit and the support member, the other of the male thread portion and the female thread portion is formed on the rotary inertia body, a bearing is provided between opposing surfaces of the rotary inertia body and the holding portion that transmit a load in the vibration direction, the bearing reducing a frictional force caused by the relative rotation of the rotary inertia body and the holding portion is provided, and a soft body is provided between the one of the drive unit and the support member and the holding portion, or between the other of the drive unit and the support member and the arm portion, the soft body allowing a relative movement between the one of the drive unit and the support member and the holding portion or between the other of the drive unit and the support member and the arm portion such that a rotation center axis of the rotary inertia body becomes an axis along the vibration direction when the drive unit and the support move relatively in a direction different from the vibration direction; The holding portion includes a holding shaft that is connected to one of the drive unit and the support and extends in the vibration direction, the rotary inertia body is formed in a cylindrical shape through which the holding shaft passes, the holding shaft has two fixing portions provided to sandwich the rotary inertia body in the vibration direction, and the bearing is provided between the surfaces of the two fixing portions and the rotary inertia body that face each other in the vibration direction. It is characterized by the presence of

[0010] In the present invention, the feed screw mechanism may be configured by a ball screw mechanism in which spherical balls are rotatably disposed inside a screw groove.

[0011] In the present invention, the lead angle of the feed screw mechanism may be smaller than 45 degrees. Effect of the Invention

[0012] According to the present invention, when the drive unit or the support body moves closer to and farther from each other due to vibration, the elastic force of the elastic member provided between them acts to suppress the vibration, and the relative movement of the drive unit and the support body to move closer to and farther from each other rotates the rotary inertia body by the vibration conversion mechanism. In this case, a torque according to the angular acceleration and moment of inertia acts as a reaction force against the force that rotates the rotary inertia body, and the torque suppresses the vibration. In other words, the linear vibration of the drive unit and the support body moving closer to and farther from each other can be suppressed by rotating the rotary inertia body.

[0013] In addition, since the above-mentioned rotating inertia body is connected or held to the drive unit and the support body by a feed screw mechanism, the rotating inertia body rotates due to vibration and also moves back and forth along its central axis, so that the inertia force caused by the rotation and the inertia force caused by the back and forth movement in the axial direction act as forces to suppress vibration, making it possible to suppress vibration more effectively.

[0014] Furthermore, when the drive unit vibrates in the vibration direction, the rotary inertia rotates to suppress the vibration, and the rotary inertia and the holding part rotate relative to each other. Therefore, by providing a bearing between the opposing surfaces of the rotary inertia and the holding part that transmit the load in the vibration direction, the rotary inertia can be rotated smoothly. In addition, by providing a soft body that allows the relative movement between one of the drive unit and the support and the holding part, or the relative movement between the other of the drive unit and the support and the arm part, when the drive unit vibrates in a direction other than the vibration direction and the drive unit and the support move relative to each other, it is possible to suppress the inclination of the rotation center axis of the rotary inertia and the axis of the arm part, and to suppress an increase in resistance force due to partial contact between the bearing and the rotary inertia. As a result, it is possible to suppress a decrease in the vibration reduction effect caused by the rotational movement of the rotary inertia. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic diagram for explaining an example of an embodiment of the present invention. [Diagram 2] 2 is an explanatory diagram showing the forces acting on a rotor, which is a rotating inertia body. FIG. [Diagram 3] 11A and 11B are diagrams for explaining the vibration reduction effect achieved by providing a thrust bearing. [Figure 4] 11A and 11B are diagrams for explaining the vibration reduction effect achieved by providing rubber. [Diagram 5] FIG. 13 is a schematic diagram for explaining another embodiment of the present invention. [Figure 6] FIG. 13 is a schematic diagram for explaining still another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] The present invention will be described based on the embodiment shown in the drawings. Note that the embodiment described below is merely one example of a specific embodiment of the present invention, and is not intended to limit the present invention.

[0017] An embodiment of the present invention is shown in schematic form in Fig. 1. The example shown here is an example configured to suppress vibration between a drive unit 1 that vibrates when an internal combustion engine or the like outputs power, and a support body (hereinafter referred to as "body") 2 such as a body that supports the drive unit 1. An elastic member 3 for suppressing vibration is provided between the drive unit 1 and the body 2. This elastic member 3 is mainly made of rubber or a spring, and may be a conventionally known engine mount.

[0018] Also, an inertial mass body that generates an inertial force for vibration suppression is provided between the drive unit 1 and the body 2. This inertial mass body is a rotary inertial body 4 that performs translational motion accompanied by rotational motion, and the rotary inertial body 4 is held by a vibration conversion mechanism that converts a force in the direction in which the drive unit 1 and the body 2 approach and separate from each other (hereinafter referred to as the vibration direction) into translational motion accompanied by rotational motion of the rotary inertial body 4. In the example shown in Fig. 1, the rotary inertial body (hereinafter referred to as the rotor) 4 is held so as to rotate about an axis along the vibration direction and to move back and forth in the vibration direction.

[0019] In the example shown here, the rotor 4 is composed of a cylindrical main shaft portion 5 formed with a large diameter, an intermediate shaft portion 6 extending from the end of the main shaft portion 5 on the drive unit 1 side and formed with a smaller diameter than the main shaft portion 5, a first retaining shaft portion 7 extending from the end of the intermediate shaft portion 6 on the drive unit 1 side and formed with a smaller diameter than the intermediate shaft portion 6, and a second retaining shaft portion 8 extending from the end of the main shaft portion 5 on the body 2 side and formed with a smaller diameter than the main shaft portion 5, and the first retaining shaft portion 7 is rotatably held by the drive unit 1.

[0020] The drive unit 1 is formed with a recess 9 into which a part of the intermediate shaft 6 and the first holding shaft 7 are inserted, and is provided with a holding wall 11 that closes the opening of the recess 9 and has a through hole 10 through which the first holding shaft 7 passes. The holding wall 11 corresponds to the "wall" in the embodiment of the present invention, and is inserted from the opening of the recess 9 to a predetermined position, with movement toward the opening restricted by a position restricting member 12 such as an E-ring or a snap ring. In other words, the holding wall 11 is integrated with the drive unit 1.

[0021] The first retaining shaft portion 7 is inserted into the through hole 10 of the retaining wall 11, and a nut 13, which corresponds to the "fixing portion" in the embodiment of the present invention, is fastened to the portion protruding from the retaining wall 11 toward the bottom side of the recess 9. That is, the retaining wall 11 is sandwiched between the nut 13 and the intermediate shaft portion 6. The rotor 4 rotates, whereas the retaining wall 11 is integrated with the drive unit 1, so that the nut 13 and the retaining wall 11 rotate relatively, and similarly, the intermediate shaft portion 6 and the retaining wall 11 rotate relatively. Therefore, a thrust bearing 14 is provided to reduce frictional resistance between the nut 13 or intermediate shaft portion 6 and the retaining wall 11. That is, the rotor 4 is held by the retaining wall 11 in a state in which it can rotate around an axis along the vibration direction and is restrained in the vibration direction. The thrust bearing 1 4, The retaining wall 11 corresponds to a "retaining portion" in an embodiment of the present invention.

[0022] Further, the second holding shaft portion 8 is held by a cylindrical shaft 15 attached to the end face 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. This feed screw mechanism 16 is configured to convert the force in the vibration direction between the drive unit 1 and the body 2 into the rotational motion of the rotor 4. Therefore, in order to suppress a decrease in the efficiency of converting the force in the vibration direction into a force in the rotation direction, that is, to reduce the frictional force in the feed screw mechanism 16 as much as possible, a ball screw mechanism is adopted in the example shown in FIG. 1.

[0023] Specifically, a screw groove 17, which is a helical groove (recess), is formed on the outer periphery of the second holding shaft portion 8, and therefore the outer periphery of the second holding shaft portion 8 is a male screw portion 18. A screw groove 19 corresponding to the screw groove 17 is formed on the inner periphery of the cylindrical shaft 15 that houses the second holding shaft portion 8, and therefore the inner periphery of the cylindrical shaft 15 is a female screw portion 20. These screw grooves 17, 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 housed in these screw grooves 17, 19 so as to be able to roll. That is, the male screw portion 18 and the female screw portion 20 are engaged with each other via the balls 21. The cylindrical shaft 15 corresponds to the "arm portion" in the embodiment of the present invention.

[0024] In addition, a flange portion 22 is formed on the end of the cylindrical shaft 15 on the body 2 side, and a plurality of through holes 23 are formed in the flange portion 22 at a predetermined interval in the circumferential direction of the flange portion 22. 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 relatively in a direction different from the vibration direction, such as the up-down direction and the depth direction on the paper. In other words, when the body 2 moves relatively in a direction different from the vibration direction with respect to the drive unit 1, the central axis of the holding wall 11 that holds the rotor 4 and the cylindrical shaft 15 is prevented from differing, that is, the central axis of the rotation of the rotor 4 is prevented from tilting with respect to the axis along the vibration direction.

[0025] 1, it is configured with a ring-shaped rubber 24. That is, when the drive unit 1 moves relative to the body 2 in a direction different from the vibration direction, the rubber 24 is bent, and the relative position between the body 2 and the cylindrical shaft 15 changes. In other words, the rigidity between the cylindrical shaft 15 and the body 2 in directions other than the vibration direction is made weaker than the rigidity between the drive unit 1 and the rotor 4 in directions other than the vibration direction.

[0026] 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. The flange portion 22 and the rubber 24 are configured to be attached to the body 2 in a state where they are overlapped. That is, a female screw 26 is formed in the body 2 at the same position as the through holes 23, 25 formed in the flange portion 22 and the rubber 24, and a bolt 27 is fastened and fixed to the female screw 26 from the opposite side of the rubber 24 and the body 2 across the flange portion 22. A recess 28 is formed to prevent the tip of the second holding shaft portion 8 from contacting the body 2 when the second holding shaft portion 8 approaches the body 2.

[0027] Next, the vibration reduction effect of the device configured as 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 Figure 2, and the equation of motion for the rotor 4 in this case is as follows:

number

[0028] In FIG. 2, f1 is the force received from the drive unit 1, f2 is the force received from the body 2, and f 2x is the axial component of the force acting from body 2, f 2y indicates the circumferential component of the force received from the body 2, r indicates the force point radius of the second holding shaft portion 8, and p indicates the screw pitch (lead) in the feed screw mechanism 16. In the above equation of motion, m indicates the mass of the rotor 4, x3 two dots (d 2 x3 / dt 2 ) is the center of gravity acceleration of the rotor 4, I is the moment of inertia of the rotor 4, θ3 two-dot (d 2 θ3 / dt 2 ) indicate the angular acceleration of the rotor 4 about the center of gravity.

[0029] Moreover, the relation between the acceleration and the angular acceleration on the rotor 4 is as follows:

number

[0030] Therefore, the force f1 that the rotor 4 receives from the drive unit 1 and the force f in the so-called vibration direction that the rotor 4 receives from the body 2 are 2x would be as follows:

number

[0031] Assuming that the drive unit 1 and the body 2 are subjected to simple harmonic motion with angular velocity ω with respect to the displacements x1 and x2 in the so-called vibration direction,

number

number

[0032] Transforming this into a determinant gives us

number

[0033] The first term in the curly brackets in the above determinant represents the inertial force related to the translational motion of the rotor 4. As can be seen from the fact that the lower rows of the matrix are all "0", the force acting on the body 2 is zero. In other words, the force that vibrates the body 2 is eliminated. This is because the rotor 4 is integrated with the drive unit 1 in the vibration direction. Note that the force that cannot be offset by the inertial force becomes larger in proportion to the mass m of the rotor 4, so in that respect it is preferable that the mass m of the rotor 4 is as small as possible.

[0034] Furthermore, the second term in the curly brackets in the above determinant represents the relative displacement between the drive unit 1 and the body 2, and if the value in the brackets, which is the coefficient of the matrix, becomes zero, the force transmitted by the elastic member 3 is offset by the inertia force of the rotor 4, making it possible to avoid or reduce the transmission of vibration to the body 2. In other words, 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, the load in the vibration direction at or near a predetermined angular velocity ω can be reduced to zero or a small value, ultimately reducing vibration.

[0035] Thus, according to the above-described device as the first embodiment of the present invention, the force generated by the drive unit 1 and the body 2 vibrating in directions toward and away from each other is utilized to rotate and linearly move the rotor 4, i.e., to cause translational motion accompanied by rotational motion, and the vibration can be reduced by the inertial force.

[0036] Here, the relationship between the lead angle in the feed screw mechanism 16, that is, the pitch p, and the circumferential length of the rotor 4 (more specifically, the second retaining shaft portion 8) will be described. The moment of inertia I for which the coefficient of the second term in the curly brackets in the above determinant is "0" is given by 4π 2 Iω 2 / p 2 =k I = (kd 2 / 4ω 2 )*(p / πd) 2 where ω is the input angular velocity and d is the diameter of the second retaining shaft portion 8. The moment of inertia I expressed by this formula is the moment of inertia that can cancel out the spring force with a spring constant k at a given input angular velocity ω. Therefore, if the pitch (lead) p is smaller than the circumferential length πd, the ratio between them becomes smaller than "1", so that the force transmitted via the elastic member 3 can be effectively canceled out. If the relationship between the pitch (lead) p and the circumferential length πd is expressed in terms of the lead angle, it is preferable that the lead angle be smaller than 45 degrees.

[0037] As described above, the vibration reduction device of the present invention reduces vibration by the inertial force of the rotor 4 by causing it to perform translational motion accompanied by rotational motion. Therefore, if a resistance force acts against the rotational and translational motion of the rotor 4, the vibration reduction effect is reduced.

[0038] As shown in FIG. 1, one end of the rotor 4 moves in the vibration direction together with the drive unit 1, and the other end is held on the cylindrical shaft 15 by the feed screw mechanism 16. Therefore, when a reaction force acts against the translational motion of the rotor 4, it is converted into a load in the direction that rotates the rotor 4, and the influence on the translational motion of the rotor 4 is small. On the other hand, the contact portion between the drive unit 1 and the rotor 4 rotates relatively while a load in the vibration direction acts on them, so the friction resistance at the contact portion greatly influences the rotational motion of the rotor 4. In other words, the smooth rotation of the rotor 4 can absorb the relative movement between the drive unit 1 and the body 2 in the vibration direction, and the vibration transmitted from the rotor 4 to the body 2 can be reduced.

[0039] Therefore, if the frictional resistance in the rotational direction at the contact point 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 fully absorbed as rotational motion of the rotor 4, and the load (kinetic energy) in the vibration direction that cannot be absorbed as rotational motion of the rotor 4 is transmitted to the body 2.

[0040] 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 thrust bearing 14 provided in the drive unit 1 is configured to transmit the load in the vibration direction to the intermediate shaft portion 6 and the nut 13.

[0041] FIG. 3 shows the results of verifying the vibration reduction effect according to the magnitude of the frictional force between the drive unit 1 and the rotor 4. In this verification experiment, the drive unit 1 was driven in the normal 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, and the inertance for each frequency was calculated from the measurement results. In addition, the vertical axis in FIG. 3 represents the inertance (the acceleration A (A / F) in the vibration direction of the body 2 relative to the load F in the vibration direction of the drive unit 1), and the horizontal axis represents the frequency. In addition, the dashed line in FIG. 3 represents the inertance when the rotor 4 is not provided and only the elastic member 3 is provided, the dashed line represents the inertance when the drive unit 1 and the rotor 4 are connected without providing the thrust bearing 14, that is, when the frictional force in the rotation direction of the rotor 4 is large, and the solid line represents the inertance when the vibration reduction device shown in FIG. 1 is used, that is, when the frictional force in the rotation direction of the rotor 4 is small.

[0042] 3, the provision of the rotor 4 can reduce vibration transmitted to the body 2. In addition, in a frequency band fr1 within a predetermined range centered on a predetermined frequency fr, vibration is reduced more significantly when the frictional force in the rotational direction of the rotor 4 is small than when the frictional force in the rotational direction of the rotor 4 is large.

[0043] On the other hand, the drive unit 1 vibrates in a direction perpendicular to the vibration direction in addition to the vibration in the direction approaching and moving away from the body 2. 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 or in the depth direction of the paper. 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. 1, and as a result, the thrust bearing 14 may come into partial contact with the intermediate shaft 6 or the nut 13, and the rotor 4 may not be able to rotate smoothly. For this reason, the vibration reduction device of the present invention is configured to connect the cylindrical shaft 15 and the body 2 via the rubber 24 as shown in FIG. 1. In other words, 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, the cylindrical shaft 15 is configured to move relative to the body 2 by the amount of the relative movement.

[0044] FIG. 4 shows the results of verifying the vibration reduction effect depending on the presence or absence of rubber 24 that absorbs movement other than the vibration direction between drive unit 1 and body 2. In this verification experiment, similar to the verification shown in FIG. 3, drive unit 1 was driven in the normal manner, and the load in the vibration direction of drive unit 1 and the acceleration in the vibration direction of body 2 were measured, and the inertance for each frequency was calculated from the measurement results. Note that the vertical axis in FIG. 4 represents the inertance, and the horizontal axis represents the frequency. Also, the dashed line in FIG. 4 represents the inertance when no rotor 4 is provided and only elastic member 3 is provided, the dashed line represents the inertance when a vibration reduction device without rubber 24 in FIG. 1 is used, and the solid line represents the inertance when the vibration reduction device shown in FIG. 1 is used.

[0045] As shown in Figure 4, within a specified frequency band fr2, the vibration reduction effect of the vibration reduction device without the rubber 24 is slightly greater, but at frequencies above the frequency band fr2, the vibration reduction effect of the vibration reduction device with the rubber 24 becomes greater as the frequency increases than that of the vibration reduction device without the rubber 24.

[0046] As described above, the rotor 4 is rotatably held, and the thrust bearing 14 is provided to reduce the frictional resistance of the portion that transmits the load in the vibration direction (thrust direction) to the rotor 4, so that the rotor 4 can rotate smoothly. In addition, by providing the soft body 24 that absorbs the relative movement between 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 relative to the body 2, the soft body 24 deforms so that the rotation center axis of the rotor 4 becomes an axis along the vibration direction, so that the rotor 4 can be prevented from tilting relative to the thrust bearing 14. This is because the soft rubber 24 is interposed between the cylindrical shaft 15 and the body 2, so that the portion that connects the cylindrical shaft 15 to the body 2 can easily move in a direction other than the vibration direction relative to the portion that holds the rotor 4 on the drive unit 1 side. As a result, it is possible to prevent an increase in resistance force due to partial contact between the thrust bearing 14 and the rotor 4, and the rotor 4 can be rotated smoothly even if the drive unit 1 vibrates in a compound manner in the vibration direction and in a direction different from the vibration direction. In other words, the thrust bearing 14 can function as intended to reduce friction, and the effect of reducing vibrations caused by the rotational movement of the rotor 4 can be prevented from decreasing.

[0047] In addition, the vibration reduction device in an embodiment of the present invention is configured so that either the drive unit 1 or the body 2 and the rotor 4 can move together in the vibration direction, and the relative movement between the drive unit 1 and the body 2 is absorbed by the rotation of the rotor 4, and it is equipped with a bearing 14 that reduces the frictional resistance of the part that transmits the load in the vibration direction to the rotor 4, and a soft body 24 that allows relative movement between the drive unit 1 and the body 2 in directions other than the vibration direction and suppresses tilting of the axis of the rotor 4.

[0048] FIG. 5 shows an example of a vibration reduction device configured so that the body 2 and the rotor 4 move in a vibration direction together. 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 a feed screw mechanism 16. Specifically, a helical screw groove 30 is formed on the outer circumferential surface of the holding shaft 29, similar to the second holding shaft portion 8. The rotor 4 shown in FIG. 5 is formed in a cylindrical shape, and a screw groove 31 corresponding to the screw groove 30 is formed on the inner surface. The balls 21 are accommodated in the screw grooves 30 and 31 so as to be able to roll. The holding shaft 29 corresponds to the "arm portion" in the embodiment of the present invention.

[0049] The rotor 4 is provided so as to be integrated with the body 2 in the vibration direction. Specifically, a cylindrical shaft 32 corresponding to the "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. That is, the cylindrical shaft 32 is formed to the drive unit 1 side from the rotor 4. The opening diameter of 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 side is restricted. The cylindrical shaft 32 may be configured so that a cylindrical main portion and a tip portion attached to the tip and having an inner diameter smaller than the opening diameter of the main portion are formed separately, and the tip portion is fixed to the main portion so as to close the open end after the rotor 4 is accommodated in the main portion.

[0050] Furthermore, a small diameter section 33 having an inner diameter smaller than the outer diameter of the rotor is formed on a portion of the cylindrical shaft 32 closer to the body 2 than the rotor 4 in the axial direction. In other words, 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 bush 34 is inserted between the outer peripheral surface of the rotor 4 and the inner peripheral surface of the cylindrical shaft 32, and a thrust bearing 35 formed in an annular shape is provided between the end face of the rotor 4 and the surface that faces the tip of the cylindrical shaft 32 and the small diameter section 33 in the vibration direction.

[0051] 1, a flange portion 36 is formed on the tip of the cylindrical shaft 32 on the body 2 side, and soft rubber 24 is sandwiched between the flange portion 36 and the body 2. The rubber 24 may be interposed between the drive unit 1 and the holder shaft 29.

[0052] In the vibration reduction device configured in this manner, when the drive unit 1 vibrates so as to approach or move away from the body 2, the rotor 4 rotates to absorb the relative movement between the drive unit 1 and the body 2 in the vibration direction, and the vibration transmitted from the drive unit 1 to the body 2 by the rotational movement can be reduced. In addition, by providing a thrust bearing 35 between the part that applies an axial load to the rotor 4, i.e., between the rotor 4 and the tip and small diameter part 33 of the cylindrical shaft 32, it is possible to reduce the generation of frictional force against the rotational movement of the rotor 4, and to suppress the reduction in the vibration reduction effect. Furthermore, by interposing a soft body such as rubber 24 between the cylindrical shaft 32 and the body 2, it is possible to suppress the rotor 4 from coming into one-sided contact with the part that applies a load along the central axis to the rotor 4, even if the drive unit 1 and the body 2 move relatively in a direction perpendicular to the central axis of the rotor 4. As a result, even if the drive unit 1 vibrates in a compound manner in the vibration direction and in a direction different from the vibration direction, the rotor 4 can be rotated smoothly, and the vibration reduction effect associated with the rotational movement of the rotor 4 can be improved.

[0053] FIG. 6 shows an example of a vibration reduction device in which a retaining shaft 29 is integrated with a drive unit 1 and a load (thrust load) in the vibration direction is transmitted from the retaining shaft 29 to a rotor 4. In the example shown in FIG. 6, the retaining 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 retaining shaft 29. The rotor 4 is restrained with respect to the retaining shaft 29 so as not to move relative to the axial direction (vibration direction) of the retaining shaft 29. That is, flange portions 37 corresponding to the "fixing portion" in the embodiment of the present invention are provided at two points on the retaining shaft 29 sandwiching the rotor 4, and the flange portions 37 are configured to restrict the axial movement of the rotor 4. These two flange portions 37 may be formed integrally with the retaining shaft 29, or may be so-called retaining ring members such as a C-ring or an E-ring.

[0054] A helical screw groove 38 is formed on the outer circumferential surface of the rotor 4, and a screw groove 19 corresponding to the screw groove 38 is formed on the inner surface of the cylindrical shaft 15 configured in the same manner as in the example shown in FIG. 1. Balls 21 are accommodated in the screw grooves 38 and 19 so as to be able to roll. That is, the rotor 4 is held on the cylindrical shaft 15 via the feed screw mechanism 16. A bush 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 that face each other in the vibration direction. The other configurations are the same as those shown in FIG. 1, and are denoted by the same reference numerals.

[0055] In the vibration reduction device configured in this manner, when the drive unit 1 vibrates so as to approach or move away from the body 2, the rotor 4 rotates to absorb the relative movement between the drive unit 1 and the body 2 in the vibration direction, and the vibration transmitted from the drive unit 1 to the body 2 by the rotational movement can be reduced. In addition, by providing a thrust bearing 40 between the part that applies an axial load to the rotor 4, i.e., between the rotor 4 and each flange portion 37, it is possible to reduce the generation of frictional force against the rotational movement of the rotor 4, and to suppress a reduction in the vibration reduction effect. Furthermore, by interposing a soft body such as rubber 24 between the cylindrical shaft 15 and the body 2, it is possible to suppress one-sided contact between the part that applies a load along the central axis to the rotor 4 and the rotor 4, even if the drive unit 1 and the body 2 move relatively in a direction perpendicular to the central axis of the rotor 4. As a result, even if the drive unit 1 vibrates in a composite manner in the vibration direction and in a direction different from the vibration direction, the rotor 4 can be rotated smoothly, and the vibration reduction effect associated with the rotational movement of the rotor 4 can be improved.

[0056] In addition, in the present invention, the above-mentioned cylindrical shafts 15, 32 may be connected to the drive unit 1, and the retaining wall 11 and retaining shaft 29 that hold the rotor 4 may be provided on the body 2, so that the configurations shown in each figure may be configured in a so-called left-right inverted manner. [Explanation of symbols]

[0057] 1 Drive unit 2. Body 3 Elastic member 4 Rotors 5 Main shaft 6 Intermediate shaft 7,8 Holding shaft part 11 Retaining wall 12 Position control member 13 Nut 14,35,40 Thrust bearings 15,32 Cylinder shaft 16 Lead screw mechanism 17,19,30,31,38 Thread groove 18 Male thread 20 Female thread 21 Ball 22, 36, 37 Flange 24 Rubber 29 Holding axis 33 Small diameter section 34,39 Bush

Claims

1. A vibration suppression device that suppresses vibration transmitted between a drive unit that vibrates in response to power output and a support that supports the drive unit, comprising: a vibration suppressing elastic member provided between the drive unit and the support; a rotary inertia body provided rotatably about an axis along a vibration direction in which the drive unit and the support body approach and move away from each other due to vibration; a holding section which holds the rotary inertia body rotatable about an axis along the vibration direction while being constrained in the vibration direction; a feed screw mechanism which has a male threaded section and a female threaded section and rotates the rotary inertia body about the axis by relative movement of the male threaded section and the female threaded section in the vibration direction; and a vibration conversion mechanism which has an arm section on which one of the male threaded section and the female threaded section is formed, and which rotates the rotary inertia body by the drive unit and the support approaching and separating from each other due to vibration, and moves the rotary inertia body back and forth in the vibration direction in which the drive unit and the support approach and separate from each other, the holding portion is provided on one of the drive unit and the support body, the arm portion is provided on the other of the drive unit and the support body, the other of the male thread portion and the female thread portion is formed on the rotating inertia body, a bearing is provided between opposing surfaces of the rotary inertia body and the holder that transmit the load in the vibration direction, the bearing reducing frictional force caused by relative rotation between the rotary inertia body and the holder; a flexible body is provided between one of the drive unit and the support and the holding section, or between the other of the drive unit and the support and the arm section, the flexible body allowing relative movement between one of the drive unit and the support and the holding section, or between the other of the drive unit and the support and the arm section, such that a rotation center axis of the rotating inertia body becomes an axis along the vibration direction, when the drive unit and the support move relatively in a direction different from the vibration direction; the holding portion includes an annular wall portion formed on one of the drive unit and the support body, an outer diameter of a tip of the rotary inertia body is smaller than an outer diameter of a central portion of the rotary inertia body in the vibration direction; A tip of the rotary inertia body is held penetrating the wall portion, a fixing portion is attached to a tip of the rotary inertia body that penetrates the wall portion, the fixing portion facing a side surface of the wall portion; The bearing is provided between a surface where the wall portion and a central portion of the rotary inertia body in the vibration direction face each other in the vibration direction, and between a surface where the wall portion and the fixed portion face each other in the vibration direction. A vibration suppression device characterized by:

2. A vibration suppression device for suppressing vibration transmitted between a drive unit that vibrates in response to power output and a support that supports the drive unit, comprising: a vibration suppressing elastic member provided between the drive unit and the support; a rotary inertia body provided rotatably about an axis along a vibration direction in which the drive unit and the support body approach and move away from each other due to vibration; a holding section which holds the rotary inertia body rotatable about an axis along the vibration direction while being constrained in the vibration direction; a feed screw mechanism which has a male threaded section and a female threaded section and rotates the rotary inertia body about the axis by relative movement of the male threaded section and the female threaded section in the vibration direction; and a vibration conversion mechanism which has an arm section on which one of the male threaded section and the female threaded section is formed, and which rotates the rotary inertia body by the drive unit and the support approaching and separating from each other due to vibration, and moves the rotary inertia body back and forth in the vibration direction in which the drive unit and the support approach and separate from each other, the holding portion is provided on one of the drive unit and the support body, the arm portion is provided on the other of the drive unit and the support body, the other of the male thread portion and the female thread portion is formed on the rotating inertia body, a bearing is provided between opposing surfaces of the rotary inertia body and the holder that transmit the load in the vibration direction, the bearing reducing frictional force caused by relative rotation between the rotary inertia body and the holder; a flexible body is provided between one of the drive unit and the support and the holding section, or between the other of the drive unit and the support and the arm section, the flexible body allowing relative movement between one of the drive unit and the support and the holding section, or between the other of the drive unit and the support and the arm section, such that a rotation center axis of the rotating inertia body becomes an axis along the vibration direction, when the drive unit and the support move relatively in a direction different from the vibration direction; the holding portion includes a cylindrical shaft that is connected to one of the drive unit and the support body, extends in the vibration direction, and accommodates the rotary inertia body therein; an inner diameter of a tip of the cylindrical shaft and an inner diameter of a small diameter portion, which is a portion on one side of the drive unit and the support body relative to the rotary inertia body, are formed smaller than an outer diameter of the rotary inertia body, The bearing is provided between the tip of the cylindrical shaft, the small diameter portion, and the rotary inertia body, which face each other in the vibration direction. A vibration suppression device characterized by:

3. A vibration suppression device for suppressing vibration transmitted between a drive unit that vibrates in response to output of power and a support that supports the drive unit, comprising: a vibration suppressing elastic member provided between the drive unit and the support; a rotary inertia body provided rotatably about an axis along a vibration direction in which the drive unit and the support body approach and move away from each other due to vibration; a holding section which holds the rotary inertia body rotatable about an axis along the vibration direction while being constrained in the vibration direction; a feed screw mechanism which has a male threaded section and a female threaded section and rotates the rotary inertia body about the axis by relative movement of the male threaded section and the female threaded section in the vibration direction; and a vibration conversion mechanism which has an arm section on which one of the male threaded section and the female threaded section is formed, and which rotates the rotary inertia body by the drive unit and the support approaching and separating from each other due to vibration, and moves the rotary inertia body back and forth in the vibration direction in which the drive unit and the support approach and separate from each other, the holding portion is provided on one of the drive unit and the support body, the arm portion is provided on the other of the drive unit and the support body, the other of the male thread portion and the female thread portion is formed on the rotating inertia body, a bearing is provided between opposing surfaces of the rotary inertia body and the holder that transmit the load in the vibration direction, the bearing reducing frictional force caused by relative rotation between the rotary inertia body and the holder; a flexible body is provided between one of the drive unit and the support and the holding section, or between the other of the drive unit and the support and the arm section, the flexible body allowing relative movement between one of the drive unit and the support and the holding section, or between the other of the drive unit and the support and the arm section, such that a rotation center axis of the rotating inertia body becomes an axis along the vibration direction, when the drive unit and the support move relatively in a direction different from the vibration direction; the holding portion includes a holding shaft that is connected to one of the drive unit and the support body and extends in the vibration direction, The rotary inertia body is formed in a cylindrical shape through which the retaining shaft passes, the retaining shaft has two fixing portions provided to sandwich the rotary inertia body in the vibration direction, The bearing is provided between the two fixed portions and the rotary inertia body, the two fixed portions and the rotary inertia body facing each other in the vibration direction. A vibration suppression device characterized by:

4. The vibration suppression device according to any one of claims 1 to 3, A vibration suppression device characterized in that the feed screw mechanism is composed of a ball screw mechanism in which spherical balls are arranged so as to be able to roll inside a screw groove.

5. The vibration suppression device according to any one of claims 1 to 4, A vibration suppression device, wherein the lead angle of the feed screw mechanism is less than 45 degrees.

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