Vibration suppression device

Abstract

The present invention relates to a vibration suppression device. The present invention provides a device that can effectively suppress the vibration of a drive unit approaching and separating from a support body by using a rotating inertial body. The device includes: an elastic member (3) for vibration suppression, provided between the drive unit (1) and the support body (2); an arm portion (9), constrained by the drive unit (1) and extending toward the support body (2); rotating inertial bodies (8a, 8b), contacting the outer surface of the arm portion (9) and rotating by the relative forward and backward movement of the arm portion (9) along with the vibration of the drive unit; holding portions (5, 6), constrained by the support body (2) and holding the rotating inertial bodies (8a, 8b) so as to be rotatable; and a position changing device (11), moving the arm portion (9) in the vibration direction to change the contact position between the rotating inertial bodies (8a, 8b) and the arm portion (9).

Description

Technical Field

[0001] The present invention relates to a device for suppressing vibration by the inertial force of a mass body, and particularly to a device for suppressing linear vibrations such as vertical vibrations by a rotating inertial body. Background Art

[0002] Devices configured to use inertial force as a force for suppressing vibration are well-known. For example, Patent Document 1 discloses a device for reducing the vibration of the torque output by an internal combustion engine (engine) by a flywheel. Briefly explaining this configuration, in the torsional vibration reduction device described in Patent Document 1, an input-side member connected to the engine and an output-side member connected to the output shaft are connected via a buffer member such as a spring damper, and the flywheel is connected to the output-side member via a centrifugal clutch. When an angular acceleration difference occurs between the input-side member and the output-side member due to the vibration of the engine torque, a torque corresponding to this angular acceleration difference and the moment of inertia of the flywheel is generated, and this torque acts as a so-called vibration damping torque for reducing vibration. It should be noted that the centrifugal clutch is configured to release and separate the flywheel as the rotational speed increases, and thus the frequency band for obtaining the vibration attenuation effect is automatically set according to the rotational speed.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2012-225482

[0006] The torsional vibration reduction device described in the above Patent Document 1 is configured to reduce vibration by the torque generated due to the occurrence of an angular acceleration difference. Therefore, the vibration system to which it can be applied is limited to a system in which the torque of a rotating member vibrates. For example, it cannot be applied to the vibration reduction of a system that vibrates vertically or horizontally, such as an engine mount. If configured to reduce the vibration of a system that vibrates vertically or horizontally, an inertial body that rotates according to the relative movement between a vibration system such as an engine mount and a support member that supports the vibration system such as the engine mount is considered. However, even in such a case where the inertial body is provided, the distance that serves as a reference for the vibration system and the support member is constant. Therefore, the inertial body and the member that contacts the inertial body and causes the inertial body to rotate repeatedly perform relative movement within a very small range with respect to a specified position, resulting in increased wear and the inability of the inertial body to rotate smoothly, or the frequency band of vibration for which the vibration reduction effect can be exerted is limited. There is room for developing new technologies to improve the vibration reduction effect. Summary of the Invention

[0007] The present invention is completed in view of the above technical problems, and its object is to provide a device that can effectively suppress the vibration of the driving unit approaching and separating from the support body by using a rotating inertial body.

[0008] To achieve the above object, the present invention is a vibration suppression device that suppresses vibration transmitted between a driving unit that vibrates as power is output and a support body that supports the driving unit. The vibration suppression device is characterized by comprising: an elastic member for vibration suppression provided between the driving unit and the support body; an arm portion constrained by one of the driving unit and the support body in the vibration direction in which the driving unit and the support body approach and separate due to vibration, and extending toward the other of the driving unit and the support body; a rotating inertial body in contact with the outer surface of the arm portion and rotating by the relative forward and backward movement of the arm portion as the driving unit vibrates; a holding portion constrained by the other of the driving unit and the support body in the vibration direction and holding the rotating inertial body so as to be rotatable; and a position changing device that moves either the rotating inertial body or the arm portion in the vibration direction to change the contact position between the rotating inertial body and the arm portion.

[0009] In the present invention, it may also be that the vibration suppression device further comprises a lubricating oil supply portion that supplies lubricating oil to the outer surface of the arm portion.

[0010] In the present invention, it may also be that the vibration suppression device further comprises a controller that controls the position changing device, and the controller is configured to move either the rotating inertial body or the arm portion in the vibration direction at a predetermined specified speed.

[0011] In the present invention, it may also be that the vibration suppression device further comprises a controller that controls the position changing device, and the controller is configured to move either the rotating inertial body or the arm portion in the vibration direction by a predetermined specified distance at each predetermined specified time.

[0012] In the present invention, it may also be that the vibration suppression device further comprises a controller that controls the position changing device, and the controller is configured to move either the rotating inertial body or the arm portion in the vibration direction by a predetermined specified distance each time the main cause of vibration of the driving unit occurs.

[0013] In the present invention, alternatively, the position changing device may be configured to change either the rotating inertial body or the arm portion to a position where the rotating inertial body and the arm portion are non-contact, and the vibration suppressing device further includes a controller that controls the position changing device. The controller is configured to: when the frequency of the vibration of the driving unit is a frequency equal to or higher than a predetermined frequency, move either the rotating inertial body or the arm portion to a position where the rotating inertial body and the arm portion are non-contact.

[0014] In the present invention, alternatively, the rotating inertial body has a center of gravity that is offset from the rotation center axis toward the outer side in the radial direction, and the vibration suppressing device further includes a controller that controls the position changing device. The controller is configured to: determine a target distance between the contact point position of the rotating inertial body and the arm portion and the center of gravity position of the rotating inertial body based on the frequency of the vibration of the driving unit, and move either the rotating inertial body or the arm portion according to the target distance.

[0015] In the present invention, alternatively, the target distance is determined to be a distance at which the restoring force of the elastic member and the inertial force of the rotating inertial body are equal in magnitude.

[0016] In the present invention, alternatively, the greater the frequency of the vibration of the driving unit, the smaller the target distance is set.

[0017] In the present invention, alternatively, the vibration suppressing device further includes a distance measuring unit that measures the distance between the driving unit and the support body. The controller is configured to: add or subtract the difference between the actual distance measured by the distance measuring unit and a predetermined reference distance between the driving unit and the support body, and the moving amount of either the rotating inertial body or the arm portion determined according to the target distance.

[0018] In the present invention, alternatively, the holding portion is provided on the support body, and the arm portion is provided on the driving unit.

[0019] In the present invention, alternatively, the rotating inertial body includes two rotating members that sandwich the arm portion in a direction orthogonal to the vibration direction.

[0020] In the present invention, alternatively, the holding portion includes a support arm. One end of the support arm is connected to one of the driving unit and the support body, and the rotating inertial body is supported at the other end of the support arm so as to be rotatable.

[0021] In the present invention, alternatively, the position changing device may be configured to move the support arm in the vibration direction.

[0022] Advantages of the Invention

[0023] According to the present invention, the vibration suppression device is configured such that when the driving unit and the support body approach and separate due to the vibration of the driving unit or the support body, the force transmitted from the driving unit to the support body is reduced by the restoring force generated by the elastic member provided between the two and the rotating inertial body, wherein the rotating inertial body contacts the outer surface of the arm portion constrained by one of the driving unit and the support body and rotates by moving back and forth relative to the arm portion. Further, the vibration suppression device is provided with a position changing device that moves one of the rotating inertial body and the arm portion in the vibration direction to change the contact position between the rotating inertial body and the arm portion. Therefore, by changing the relative position between the rotating inertial body and the arm portion by the position changing device, wear caused by the repeated relative movement between the rotating inertial body and the arm portion within a range based on a specified position can be suppressed, thereby reducing the vibration level transmitted to the support body. The increase in the vibration level transmitted to the support body can be suppressed by separating the rotating inertial body in a region where the vibration level transmitted to the support body increases by the rotating inertial body and the elastic member, or the vibration region (frequency) with a low vibration level can be expanded, etc. As a result, the vibration when the driving unit and the support body approach can be effectively suppressed, and the increase in the vibration level transmitted to the support body can be suppressed or the vibration level can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram for explaining an example of an embodiment of the present invention.

[0025] Figure 2 is a diagram showing the change in the contact point position between the arm and the rotor when the extension amount of the arm is increased.

[0026] Figure 3 is a diagram showing a method of changing the extension amount of the arm achieved by the position changing device.

[0027] Figure 4 is a diagram showing the change in the restoring force of the elastic member and the inertial force of the rotor corresponding to the frequency of the vibration of the driving unit.

[0028] Figure 5 is a diagram showing the vibration level.

[0029] Figure 6 is a diagram showing a state where the arm and the rotor are not in contact.

[0030] Figure 7 is a flowchart for explaining an example of controlling the position changing device according to the engine speed.

[0031] Figure 8 It is a diagram showing the vibration level caused by making the arm and the rotor in a non-contact state through the position changing device.

[0032] Figure 9 It is a schematic diagram showing an example of the structure in which the center of gravity position is deviated from the rotation center of the rotor.

[0033] Figure 10 It is a schematic diagram showing a state in which the contact point position between the arm and the rotor is close to the center of gravity position of the rotor.

[0034] Figure 11 It is a diagram showing the magnitude of the force transmitted to the main body corresponding to the frequency for each phase of the center of gravity position of the rotor.

[0035] Figure 12 It is a flowchart showing an example of controlling the position changing device according to the frequency of vibration of the drive unit.

[0036] Figure 13 It shows the execution of Figure 12 A diagram showing the change in the phase of the center of gravity position of the rotor, the change in the inertial force transmitted to the main body, and the change in the total force transmitted to the main body in the case of the control example shown.

[0037] Figure 14 It is a schematic diagram showing an example in which the distance between the drive unit and the main body changes with the change in the posture of the drive unit caused by the acceleration and deceleration of the vehicle.

[0038] Figure 15 It is a schematic diagram showing an example of a vibration suppression device having a sensor for measuring the distance between the drive unit and the main body.

[0039] Figure 16 It is a flowchart for explaining an example of the control of the position changing device considering the change in the distance between the drive unit and the main body.

[0040] Figure 17 It shows the change in the AC component and the DC component of the clearance amount measured by the clearance sensor, the change in the actual clearance amount and the target clearance amount, and the change in the clearance amount in the case of performing the Figure 16 control shown.

[0041] Explanation of reference numerals:

[0042] 1 Drive unit; 2 Main body; 3 Elastic member; 4 Support arm; 5 Upper arm; 6 Lower arm; 7 Branch portion; 8a, 8b Rotor; 9 Arm; 10 Lubricating oil supply portion; 11 Position changing device; 12 Electronic control unit (ECU); 13 Clearance sensor. Detailed implementation mode

[0043] The present invention will be described based on the embodiments shown in the accompanying drawings. It should be noted that the embodiments described below are merely examples in the case of embodying the present invention and do not limit the present invention.

[0044] In Figure 1 an embodiment of the present invention is schematically shown. The example shown here is an example of suppressing vibration between a drive unit 1 of a vehicle configured to suppress vibration when power such as that of an internal combustion engine is output and a support body (hereinafter referred to as the main body) 2 that supports the drive unit 1. An elastic member 3 for suppressing vibration is provided between the drive unit 1 and the main body 2. The elastic member 3 is mainly composed of rubber or a spring and is configured to generate a restoring force in a direction to move the drive unit 1 away from the main body 2 if the distance in the direction in which the drive unit 1 approaches and moves away from the main body 2 (hereinafter referred to as the vibration direction) is shorter than a predetermined reference distance, and to generate a restoring force in a direction to move the drive unit 1 closer to the main body 2 if the distance in the vibration direction between the drive unit 1 and the main body 2 is longer than the reference distance. The elastic member 3 can be a conventionally known engine mount.

[0045] In addition, an inertial mass body that generates an inertial force for vibration suppression is provided between the drive unit 1 and the main body 2. The inertial mass body is a rotational inertial body that performs a translational motion accompanying a rotational motion, and the rotational inertial body is held by a vibration conversion mechanism that is a mechanism for converting a force in the direction in which the drive unit 1 approaches and moves away from the main body 2 into a translational motion accompanying the rotational motion of the rotational inertial body.

[0046] In Figure 1 the example shown, a support arm 4 that extends from the main body 2 toward the drive unit 1 side and is constrained by the main body 2 in the vibration direction, an upper side arm 5 and a lower side arm 6 that branch from the tip of the support arm 4 into two are provided. Specifically, a branch portion 7 that is formed perpendicular to the vibration direction and the tip of the support arm 4 is connected to the central portion in the long dimension direction is provided, and the upper side arm 5 that extends in the vibration direction is integrated with one end of the branch portion 7, and the lower side arm 6 that extends in the vibration direction is integrated with the other end of the branch portion 7. That is, the upper side arm 5 and the lower side arm 6 are arranged in parallel. It should be noted that the support arm 4, the upper side arm 5, and the lower side arm 6 correspond to the "holding portion" of the embodiment of the present invention.

[0047] A rotor (hereinafter referred to as the upper rotor) 8a is rotatably held at the tip of the upper arm 5, and a rotor (hereinafter referred to as the lower rotor) 8b is rotatably held at the tip of the lower arm 6. These respective rotors 8a, 8b correspond to the "rotating members" of the embodiment of the present invention and function as the above-described rotating inertial bodies. Each of the rotors 8a, 8b is formed in a disc shape with the same outer diameter and is arranged at a prescribed gap in a direction perpendicular to the vibration direction.

[0048] The arm portion 9 sandwiched by the respective rotors 8a, 8b described above is configured to be constrained in the vibration direction of the drive unit. The cross-sectional shape of the arm portion 9 is formed in a circular or rectangular shape, and the outer peripheral surface of the arm portion 9 is arranged to contact the respective rotors 8a, 8b. Specifically, the arm portion 9 is arranged such that when the arm portion 9 and the drive unit 1 move back and forth in the vibration direction integrally, the force in the vibration direction of the arm portion 9 causes the respective rotors 8a, 8b to rotate, and thus contacts the respective rotors 8a, 8b. That is, a vibration conversion mechanism is constituted by the respective rotors 8a, 8b and the arm portion 9.

[0049] It should be noted that it may also be configured such that external teeth are formed on the rotors 8a, 8b and rack teeth are formed on the outer surface of the arm portion 9, and the force in the vibration direction of the arm portion 9 is transmitted as a torque for rotating the rotors 8a, 8b. It may also be configured such that the outer peripheral surfaces of the rotors 8a, 8b and the outer surface of the arm portion 9 are formed as smooth surfaces, and the force in the vibration direction of the arm portion 9 is transmitted as a torque for rotating the rotors 8a, 8b through the frictional force generated on the smooth surfaces.

[0050] In the vibration suppression device configured as described above, when the drive unit 1 and the main body 2 move relative to each other, a force corresponding to the moment of inertia of the rotors 8a, 8b and the acceleration of the drive unit 1 approaching or separating from the main body 2 (hereinafter referred to as the inertial force) is generated. Specifically, when the drive unit 1 approaches the main body 2, the inertial force of the rotors 8a, 8b acts in a direction to cause the main body 2 to approach the drive unit 1 side, and when the drive unit 1 separates from the main body 2, the inertial force of the rotors 8a, 8b acts in a direction to cause the main body 2 to separate from the drive unit 1. In contrast, when the drive unit 1 approaches the main body 2, the elastic member 3 is compressed and the restoring force acts in a direction to cause the main body 2 to separate from the drive unit 1, and when the drive unit 1 separates from the main body 2, the elastic member 3 is stretched and the restoring force acts in a direction to cause the main body 2 to approach the drive unit 1 side. Therefore, the vibration suppression device of the present invention is configured to reduce the force transmitted from the drive unit 1 to the main body 2 by the balance between the inertial force acting on the main body 2 and the restoring force of the elastic member 3, thereby suppressing the vibration from being transmitted to the main body 2.

[0051] On the other hand, in the vibration suppression device configured as described above, the drive unit 1 approaches and separates from the main body 2 in such a manner that the distance increases and decreases with the reference distance as the center. Therefore, the elastic member 3 expands and contracts with the predetermined reference length as the center. In addition, the relative positions of the arm portion 9 and the respective rotors 8a, 8b also change with the predetermined positions as the reference. Therefore, the outer surface of the arm portion 9 and the outer circumferential surfaces of the respective rotors 8a, 8b repeatedly roll and contact within a specified range. That is, the respective rotors 8a, 8b contact the specified range of the outer surface of the arm portion 9, and similarly, the arm portion 9 contacts the specified range of the outer circumferential surfaces of the respective rotors 8a, 8b. In Figure 1 In order to facilitate, lines indicating the central portions (reference phases) of the ranges where the rotors 8a, 8b contact the outer surface of the arm portion 9 are marked on the side surfaces of the rotors 8a, 8b. As a result, since the lubricating oil for reducing the wear of the contact portions between the outer surface of the arm portion 9 and the outer circumferential surfaces of the respective rotors 8a, 8b is gradually scraped out to the outside of the contact surface, etc., the wear of the contact surface may be aggravated.

[0052] The vibration suppression device according to an embodiment of the present invention is configured to supply lubricating oil to the contact surface in order to suppress wear at the contact points between the arm portion 9 and the rotors 8a, 8b, and to change the contact positions between the arm portion 9 and the rotors 8a, 8b. In Figure 1 In the example shown, a lubricating oil supply portion 10 for supplying lubricating oil to the outer circumferential surface of the arm portion 9 is provided at the end portion of the arm portion 9 on the drive unit 1 side. In addition, a position changing device 11 for extending the arm portion 9 toward the main body 2 side or retracting it toward the drive unit 1 side is provided at the end portion of the arm portion 9 on the drive unit 1 side in the vibration direction.

[0053] The position changing device 11 can be configured, for example, to move the arm portion 9 back and forth in the vibration direction by the power of a motor and is composed of a rack and pinion mechanism or the like. That is, a pinion is connected to the output shaft of the motor that functions as an actuator, and rack teeth meshing with the pinion are formed on the outer surface of the arm portion 9. Therefore, it is configured to be able to control the extension amount of the arm portion 9 in the vibration direction by controlling the rotation angle of the motor. That is, when Figure 2 As shown, when the extension amount of the arm portion 9 is increased, the upper rotor 8a rotates counterclockwise and the lower rotor 8b rotates clockwise. Therefore, when the drive unit 1 vibrates, the rotors 8a, 8b reciprocate in the rotational direction with the rotated positions as the center, and the arm portion 9 moves back and forth in the vibration direction with the contact point positions between the rotated rotors 8a, 8b and the arm portion 9 as the center. It should be noted that Figure 2 The shaded portion in

[0054] There is an electronic control unit (hereinafter referred to as ECU) 12 for controlling the above-described position changing device 11. This ECU 12 corresponds to the "controller" in the embodiment of the present invention, and like the conventional ECU, it has a microcomputer as the main body. This ECU 12 is configured to: input signals from various sensors provided in the vehicle, and control the signals output to the actuator based on the input signals and pre-stored arithmetic expressions, maps, etc.

[0055] Specifically, as shown in (a) of Figure 3 , a signal is output from the ECU 12 to the position changing device 11 so that the arm portion 9 extends and retracts continuously at a predetermined speed between the minimum value and the maximum value of the extension amount of the arm portion 9. Or, as shown in (b) of Figure 3 , the ECU 12 is configured to: change a predetermined change amount and the extension amount of the arm portion 9 between the minimum value and the maximum value of the extension amount of the arm portion 9 each time the engine, which is the main cause of vibration of the driving unit 1, starts. Or, as shown in (c) of Figure 3 , the ECU 12 is configured to: change a predetermined change amount and the extension amount of the arm portion 9 between the minimum value and the maximum value of the extension amount of the arm portion 9 at each predetermined period of time. Here, the minimum value of the extension amount of the arm portion 9 is the extension amount that can maintain the state of the arm portion 9 being in contact with the rotors 8a, 8b even when the arm portion 9 moves back and forth in the vibration direction, and the maximum value is determined such that the tip of the arm portion 9 does not contact the branch portion 7 even when the arm portion 9 moves back and forth in the vibration direction.

[0056] It should be noted that the lubricating oil supply portion 10 can be configured to spray atomized oil near the contact point positions of the above-described arm portion 9 and the rotors 8a, 8b. In addition, the position changing device 11 can be configured to move the support arm 4 back and forth in the vibration direction, that is, configured to move the rotors 8a, 8b toward the driving unit 1 side or toward the main body 2 side. Moreover, the rotors 8a, 8b are not limited to being held by the main body 2, and can also be held by the driving unit 1. Specifically, the support arm 4 that supports the rotors 8a, 8b can be connected to the driving unit 1, and the arm portion 9 that contacts the rotors 8a, 8b and rotates the rotors 8a, 8b can be connected to the main body 2. In addition, only one rotor 8a, 8b can be provided instead of two rotors 8a, 8b.

[0057] By setting the position changing device 11 as described above, the contact points between the arm portion 9 and the rotors 8a and 8b can be changed, that is, the phase which is the center of the reciprocating movement of the rotors 8a and 8b in the rotational direction and the center position of the outer surface where the arm portion 9 contacts the rotors 8a and 8b and moves back and forth can be changed. Therefore, wear of the contact portions of the arm portion 9, the rotors 8a and 8b can be suppressed. That is, the rotors 8a and 8b can rotate smoothly, and therefore an increase in the vibration level transmitted to the main body 2 can be suppressed.

[0058] In the vibration suppression device configured as described above, the inertial forces of the rotors 8a and 8b and the restoring force of the elastic member 3 are transmitted to the main body 2, and these forces act in opposite directions. The inertial force of the rotors 8a and 8b becomes the magnitude of the acceleration based on the vibration direction of the arm portion 9. Therefore, as Figure 4 shown, the restoring force (dashed line) of the elastic member 3 is constant regardless of the vibration frequency, whereas the higher the vibration frequency, the greater the value of the inertial force (solid line) of the rotors 8a and 8b becomes. That is, at the frequency (hereinafter, referred to as the first specified frequency) f1 where the restoring force of the elastic member 3 and the inertial forces of the rotors 8a and 8b become the same magnitude, the reduction effect of the transmission force transmitted to the main body 2 is the greatest. The closer the frequency is to the first specified frequency f1, the more gradually the reduction effect of the transmission force increases. Conversely, the greater the frequency is than the first specified frequency f1, the more gradually the reduction effect of the transmission force decreases. Therefore, as Figure 5 shown by the solid line in, in the frequency band above the second specified frequency f2 which is higher than the first specified frequency f1, as Figure 5 shown by the dashed line in, a vibration suppression device without the rotors 8a and 8b will reduce the vibration level transmitted to the main body 2.

[0059] Therefore, the vibration suppression device of the present invention is configured such that when the drive unit 1 vibrates in the frequency band above the second specified frequency f2, as Figure 6 shown, the position changing device 11 shortens the arm portion 9 and withdraws the arm portion 9 from each of the rotors 8a and 8b, that is, becomes non-contact.

[0060] Figure 7 A flowchart showing an example for explaining this control is shown. In Figure 7 the example shown, first, the engine speed Ne is acquired (step S1). This step S1 is a step for obtaining the frequency of the vibration of the drive unit 1. Here, the main cause of the vibration of the drive unit 1 is mainly the vibration caused by the combustion of the engine. In the case where the engine is a four-stroke four-cylinder engine, there are two combustion strokes in one rotation of the engine. Therefore, the vibration frequency (Hz) can be converted to the engine speed (rpm) by multiplying this value by 30. Therefore, here, the engine speed Ne is obtained instead of the vibration frequency of the drive unit 1.

[0061] Next, it is determined whether the engine speed Ne obtained in step S1 is less than a preset first specified speed Ne1 (step S2). This first specified speed Ne1 is the engine speed that becomes Figure 5 the second specified frequency f2 in

[0062] That is, the second specified frequency f2 at which the reduction effect of the transmission force by setting the rotors 8a and 8b is lower than that without setting the rotors 8a and 8b is obtained in advance through calculations, experiments, etc., and the speed obtained by multiplying the value of this second specified frequency f2 by 30 is determined as the first specified speed Ne1. This second specified frequency f2 corresponds to the "specified frequency" in the embodiment of the present invention.

[0063] When an affirmative determination is made in step S2 because the engine speed Ne is less than the first specified speed Ne1, the effect of reducing vibration by rotating the rotors 8a and 8b becomes greater. Therefore, the extension amount of the arm portion 9 is extended to a specified amount or more (step S3), and this routine is temporarily ended. This specified amount is the extension amount that can maintain the state of contact between the arm portion 9 and each of the rotors 8a and 8b when the drive unit 1 vibrates.

[0064] Note that the position changing device 11 may also be configured to move the support arm 4 back and forth in the vibration direction, that is, configured to move the rotors 8a and 8b toward the drive unit 1 side or toward the main body 2 side. In addition, the rotors 8a and 8b are not limited to being held by the main body 2, and may also be held by the drive unit 1. Specifically, the support arm 4 that supports the rotors 8a and 8b may be connected to the drive unit 1, and the arm portion 9 that contacts the rotors 8a and 8b and rotates the rotors 8a and 8b may be connected to the main body 2. Further, instead of providing two rotors 8a and 8b, only one rotor may be provided.

[0065] As described above, by expanding and contracting the arm portion 9 according to the frequency of vibration of the drive unit 1, in other words, by switching the availability of rotation of the rotors 8a and 8b implemented by the arm portion 9, it is possible to suppress the inertial force of the rotors 8a and 8b from being transmitted to the main body 2 in a frequency band of the second specified frequency f2 or higher. Therefore, as Figure 8 shown, it is possible to reduce the vibration level in a frequency band of the second specified frequency f2 or higher compared to the vibration level (dashed line) in the case where the above-described control example is not executed.

[0066] As Figure 5 shown, when the drive unit 1 vibrates at the first specified frequency f1, the above-described vibration suppression device can minimize the transmission force transmitted to the main body 2. The further the frequency is from the first specified frequency f1, the lower the reduction effect of the transmission force. That is, the frequency band in which the reduction effect of the transmission force transmitted to the main body 2 can be exerted is limited. Therefore, the vibration suppression device according to the embodiment of the present invention is configured to expand the range of frequencies at which the transmission force transmitted to the main body 2 becomes low.

[0067] Figure 9 An example of the vibration suppression device is shown in Figure 9 The shown vibration suppression device is different from the one shown in Figure 1 that the center of gravity positions G of the rotors 8a and 8b deviate from the rotation center axis of the rotors 8a and 8b toward the outer side in the radial direction.

[0068] As Figure 9 shown, when the center of gravity positions G of the rotors 8a and 8b deviate from the rotation center axis of the rotors 8a and 8b, the farther the distance between the contact point position of the arm portion 9 and the rotors 8a and 8b and the center of gravity position G, the greater the inertial force of the rotors 8a and 8b. That is, when starting from the state where the distance between the contact point position of the arm portion 9 and the rotors 8a and 8b and the center of gravity position G is the farthest as shown in Figure 9 and the extension amount of the arm portion 9 is increased as shown in Figure 10 so that the contact point position and the center of gravity position G of the arm portion 9 and the rotors 8a and 8b approach each other, the inertial force of the rotors 8a and 8b becomes smaller.

[0069] Figure 11 The relationship between the phase α of the center of gravity position G based on the center of gravity position farthest from the contact point position of the arm portion 9 and the rotors 8a and 8b and the force (transmission force) transmitted to the main body 2 is shown in Figure 11 shown. As Figure 11 shown, the smaller the phase α, the greater the transmission force. That is, the frequency at which the restoring force of the elastic member and the inertial force are balanced as shown by the dotted line in

[0070] and the transmission force transmitted to the main body 2 is reduced to the minimum can be changed by controlling the phase α of the center of gravity position G. Figure 12 Therefore, the position changing device 11 is controlled so that the distance between the contact point position of the rotors 8a and 8b and the arm portion 9 and the center of gravity position G of the rotors 8a and 8b becomes a target distance at which the transmission force transmitted to the main body 2 can be reduced, according to the frequency of the vibration of the drive unit 1. An example of the control is shown in Figure 12 In the example shown in Figure 7The example shown similarly obtains the engine speed Ne (step S1). Next, it is determined whether the engine speed Ne obtained in step S1 is less than the second specified speed Ne2 (step S10). This second specified speed Ne2 is the engine speed that becomes the first specified frequency f1 in Figure 5 and is set to a speed lower than the above-mentioned first specified speed Ne1. That is, it is possible to obtain in advance through calculations, experiments, etc. the frequency at which the transmission force transmitted to the main body 2 is minimized at the phase α of the center of gravity position G where the distance between the contact point positions of the arm 9 and the rotors 8a and 8b and the center of gravity position G is the farthest, and the second specified speed Ne2 is determined based on this frequency.

[0071] When an affirmative determination is made in step S10 because the engine speed Ne is less than the second specified speed Ne2, the extension amount of the arm 9 is controlled so that the phase α of the center of gravity position G becomes the phase that is the farthest from the contact point position of the arm 9 and the rotors 8a and 8b, that is, so that the phase of the rotors 8a and 8b becomes "0" (step S11), and this routine is temporarily ended.

[0072] Conversely, when a negative determination is made in step S10 because the engine speed Ne is equal to or higher than the second specified speed Ne2, the target distance between the contact point position of the rotors 8a and 8b and the center of gravity position of the rotors 8a and 8b corresponding to this engine speed Ne is determined, and the phase α of the center of gravity position G of the rotors 8a and 8b that becomes this target distance is set as the target value to control the extension amount of the arm 9 (step S12), and this routine is temporarily ended.

[0073] In Figure 13 shows (a) the change in the phase (eccentric phase) α of the center of gravity position G of the rotors 8a and 8b, (b) the change in the inertial force transmitted to the main body 2, and (c) the change in the force (total value) transmitted to the main body 2 in the case where the control example shown in Figure 12 is executed. It should be noted that in Figure 13 in (a), (b), and (c), the frequency of the vibration of the drive unit 1 (equivalent to the engine speed) is used on the horizontal axis.

[0074] As Figure 13 shown in (a), in the region where the frequency of the vibration of the drive unit 1 is lower than the first specified frequency f1, step S11 in Figure 12 is executed. Therefore, the phase α of the center of gravity position G is maintained at the phase (eccentric phase) that is the farthest from the contact point position of the arm 9 and the rotors 8a and 8b. As a result, in the region of frequencies lower than the first specified frequency f1, as Figure 13 shown in (b), the inertial force transmitted to the main body 2 gradually increases toward a magnitude that balances with the restoring force of the elastic member 3 as the frequency increases. Therefore, asFigure 13 As shown in (c), the magnitude of the total force transmitted to the main body 2 gradually decreases and becomes minimum at the first specified frequency f1.

[0075] On the other hand, as Figure 13 shown in (a), in the frequency band where the frequency of the vibration of the drive unit 1 is higher than the first specified frequency f1, the phase α of the center-of-gravity position G of the rotors 8a and 8b increases as the frequency increases. That is, the extension amount of the arm portion 9 is reduced. Therefore, as Figure 13 shown by the solid line in (b), the inertial force transmitted to the main body 2 and the restoring force of the elastic member 3 are balanced with each other and are maintained constant. As a result, as Figure 13 shown in (c), the magnitude of the total force transmitted to the main body 2 is maintained constant starting from the first specified frequency f1. That is, the frequency range in which the transmission force transmitted to the main body 2 is reduced to the minimum can be expanded. It should be noted that in Figure 13 (b) and Figure 13 (c), the magnitude of the inertial force transmitted to the main body 2 and the magnitude of the total force transmitted to the main body 2 are shown without changing the extension amount of the arm portion 9.

[0076] Here, the direction of clockwise rotation of the upper rotor 8a is set as a positive value, but in the case of a frequency higher than the first specified frequency f1, as long as the distance to the contact point position of the arm portion 9 and the rotors 8a and 8b can be changed, the extension amount of the arm portion 9 can also be increased and the upper rotor 8a can be rotated counterclockwise.

[0077] The above-described position changing device 11 may also be configured to move the support arm 4 back and forth in the vibration direction, that is, configured to move the rotors 8a and 8b toward the drive unit 1 side or toward the main body 2 side. In addition, instead of providing two rotors 8a and 8b, only one rotor may be provided.

[0078] As described above, when the engine speed Ne is higher than the second specified speed Ne2, that is, when the frequency of the vibration of the drive unit 1 is higher than the first specified frequency f1, the extension amount of the arm portion 9 is changed by the position changing device 11 and the phase α of the center-of-gravity position G of the rotors 8a and 8b is changed. Thereby, the frequency band in which the transmission force to the main body 2 can be reduced can be expanded. In other words, the transmission force transmitted to the main body 2 when the drive unit 1 vibrates at a frequency higher than the first specified frequency f1 can be reduced.

[0079] On the other hand, when the vehicle accelerates or decelerates, an inertial force acts on the drive unit 1. Thus, when the inertial force acts on the drive unit 1, due to changes in the posture of the drive unit 1, etc., the distance in the vibration direction between the drive unit 1 and the main body 2, more specifically, the distance in the vibration direction between the position where the arm portion 9 is connected to the drive unit 1 and the position where the support arm 4 is connected to the main body 2 may change with respect to a predetermined distance. That is, as shown by the dashed line in Figure 14 , during acceleration, the upper side of the drive unit 1 approaches the main body 2 side, and the lower side of the drive unit 1 moves away from the main body 2, etc., and the drive unit 1 may tilt. In this case, the distance in the vibration direction between the position where the arm portion 9 is connected to the drive unit 1 and the position where the support arm 4 is connected to the main body 2 changes with respect to a predetermined reference distance (in Figure 14 , it moves away).

[0080] Therefore, when the posture of the drive unit 1 changes and the distance in the vibration direction between the position where the arm portion 9 is connected to the drive unit 1 and the position where the support arm 4 is connected to the main body 2 changes with respect to a predetermined reference distance, the relative positions of the arm portion 9 and the rotors 8a, 8b change, and thus, the amount of change in the relative positions of the rotors 8a, 8b rotates. As a result, the phase α of the center of gravity position G of the rotors 8a, 8b changes with respect to a predetermined reference phase. Therefore, when controlling the extension amount of the arm portion 9 based on the reference phase, the phase α of the center of gravity position G of the rotors 8a, 8b may deviate from the expected phase. That is, it may not be possible to reduce the transmission force transmitted to the main body 2 as expected.

[0081] The vibration suppression device according to an embodiment of the present invention is configured to control the position changing device 11 in consideration of changes in the posture of the drive unit 1 as described above. Specifically, the vibration suppression device is configured to add or subtract the difference between the actual distance between the drive unit 1 and the main body 2 and a predetermined reference distance between the drive unit 1 and the main body 2 from the extension amount of the arm portion 9 that is used to make the transmission force transmitted to the main body 2 decrease and that is the phase α of the center of gravity position G of the rotors 8a, 8b determined according to the frequency of the vibration of the drive unit 1.

[0082] Figure 15 The vibration suppression device shown is configured to measure the distance between the tip of the arm portion 9 and the branch portion 7 (hereinafter, referred to as the clearance amount) instead of measuring the distance between the drive unit 1 and the main body 2. Specifically, a clearance sensor 13 for measuring the clearance amount is provided at the tip of the arm portion 9. It should be noted that other configurations are the same as those of the vibration suppression device shown in Figure 9 , and the same reference numerals are used and their descriptions are omitted.

[0083] The gap sensor 13 corresponds to the "distance measurement unit" of the embodiment of the present invention. The gap sensor 13 is connected to the ECU 12, and the ECU 12 is configured to control the position changing device 11 based on the signal input from the gap sensor 13. Figure 16 FIG. is a flowchart for explaining an example of this control. First, the actual gap amount L1 is calculated (step S20). The actual gap amount L1 is a value for determining the distance between the drive unit 1 and the main body 2 due to the posture change of the drive unit 1, and does not include the change in the gap amount accompanying the vibration of the drive unit 1. On the other hand, as Figure 17 shown in (a) of, the gap amount measured by the gap sensor 13 includes the change in the gap amount accompanying the vibration of the drive unit 1 (AC component) and the change in the gap amount caused by the change in the distance between the drive unit 1 and the main body 2 due to the posture change of the drive unit 1, etc. (DC component). Therefore, in step S20, by performing low-pass filtering on the gap amount detected by the gap sensor 13, the gap amount of the vibration component is removed to obtain the actual gap amount L1. It should be noted that, as described above, instead of measuring the distance between the drive unit 1 and the main body 2, the gap amount is measured, and the actual gap amount L1 corresponds to the "actual distance" of the embodiment of the present invention.

[0084] Next, the target gap amount L2 is calculated (step S21). The target gap amount L2 in step S2 is the gap amount corresponding to the phase α of the center of gravity positions G of the rotors 8a and 8b determined based on the Figure 12 control example shown. Therefore, the target gap amount L2 can be obtained by adding the movement amount of the arm portion 9 required for the phase determined in step S12 of Figure 12 to the reference gap amount, where the reference gap amount is the gap amount when the distance between the drive unit 1 and the main body 2 is a predetermined distance and the phase α of the center of gravity positions G of the rotors 8a and 8b is "0". It should be noted that, as described above, instead of measuring the distance between the drive unit 1 and the main body 2, the gap amount is measured, and the reference gap amount corresponds to the "reference distance" of the embodiment of the present invention.

[0085] Next, it is determined whether the difference ΔL between the actual gap amount L1 obtained in step S20 and the target gap amount L2 obtained in step S21 is greater than a specified value (step S22). That is, it is determined whether the drive unit 1 and the main body 2 are farther apart than a predetermined distance. Therefore, the specified value in step S22 described above can be set to zero. It should be noted that a value slightly larger than zero or a value slightly smaller than zero can also be set as the specified value in consideration of measurement errors, etc.

[0086] As Figure 17As shown in (b), when a positive determination is made in step S22 because the difference ΔL between the actual clearance L1 (solid line) and the target clearance L2 (dashed line) is greater than the specified value, the extension amount of the arm portion 9 is increased by the amount of the difference ΔL (step S23), and this routine is temporarily terminated.

[0087] Conversely, when a negative determination is made in step S22 because the difference ΔL between the actual clearance L1 and the target clearance L2 is less than or equal to the specified value, it is determined whether the difference ΔL between the actual clearance L1 and the target clearance L2 is less than the specified value (step S24). That is, it is determined whether the drive unit 1 and the main body 2 are closer than a predetermined distance. Therefore, similar to step S22, the specified value in step S24 can also be set to zero. In addition, a value slightly larger or slightly smaller than zero can be set as the specified value in consideration of measurement errors or the like.

[0088] When a positive determination is made in step S24 because the difference ΔL between the actual clearance L1 and the target clearance L2 is less than the specified value, the extension amount of the arm portion 9 is decreased by the amount of the difference ΔL (step S25), and this routine is temporarily terminated. Conversely, when a negative determination is made in step S24 because the difference ΔL between the actual clearance L1 and the target clearance L2 is equal to the specified value, the distance between the drive unit 1 and the main body 2 is maintained at a predetermined distance. Therefore, this routine is temporarily terminated without particularly controlling the position changing device 11.

[0089] It should be noted that, similar to the example Figure 9 shown, the position changing device 11 can also be configured to move the support arm 4 back and forth in the vibration direction, that is, configured to move the rotors 8a, 8b toward the drive unit 1 side or toward the main body 2 side. In addition, instead of providing two rotors 8a, 8b, only one rotor can be provided. Moreover, as long as the clearance sensor 13 can obtain the relative distance between the drive unit 1 and the main body 2, it can directly measure the distance between the drive unit 1 and the main body 2, or the rotation angle of the rotors 8a, 8b can be measured by an encoder instead of the sensor that measures the distance between the tip of the arm portion 9 and the branch portion 7. Additionally, in the above control example, it is configured to control the position changing device 11 based on the difference between the actual clearance L1 and the target clearance L2, and the target clearance L2 is obtained by adding the movement amount of the arm portion 9 for reducing the transmission force transmitted to the main body 2 to the reference clearance. However, it is substantially the same as first obtaining the difference between the actual clearance L1 and the reference clearance, and then adding or subtracting this difference from the movement amount of the arm portion 9 for reducing the transmission force transmitted to the main body 2 to control the position changing device 11, and there is no limitation on the operation order or the like.

[0090] As described above, the relative distance between the drive unit 1 and the main body 2 accompanying the change in the posture of the drive unit 1 is measured by the gap sensor 13, and thereby, the position changing device 11 is controlled in consideration of the change in the phase α of the center of gravity position G of the rotors 8a and 8b accompanying the change in the relative distance. Therefore, the phase α of the center of gravity position G of the rotors 8a and 8b can be controlled to a phase that reduces the transmission force transmitted to the main body 2. As a result, as shown in (c) of Figure 17 , the arm portion 9 can move back and forth in the vibration direction along with the vibration of the drive unit 1 with the extension amount of the arm portion 9 that can reduce the transmission force transmitted to the main body 2 as the center. In other words, the rotors 8a and 8b can be rotated in the rotation direction along with the vibration of the drive unit 1 with the phase that can reduce the transmission force transmitted to the main body 2 as the center. Therefore, even when the posture of the drive unit 1 changes due to acceleration and deceleration or the like, the transmission force transmitted to the main body 2 can be reduced.

Claims

1. A vibration suppression device that suppresses vibration transmitted between a drive unit that vibrates with output power and a support body that supports the drive unit, wherein the vibration suppression device is characterized by comprising: An elastic member for vibration suppression, provided between the drive unit and the support body; An arm portion that is constrained by one of the drive unit and the support body in a vibration direction in which the drive unit and the support body approach and separate due to vibration, and extends toward the other of the drive unit and the support body; A rotating inertial body that contacts an outer surface of the arm portion and rotates by the arm portion moving relatively back and forth with the vibration of the drive unit; A holding portion that is constrained by the other of the drive unit and the support body in the vibration direction and holds the rotating inertial body so as to be rotatable; and A position changing device that moves either the rotating inertial body or the arm portion in the vibration direction to change a contact position between the rotating inertial body and the arm portion.

2. The vibration suppression device according to claim 1, wherein It further comprises a lubricating oil supply portion that supplies lubricating oil to the outer surface of the arm portion.

3. The vibration suppression device according to claim 1 or 2, wherein It further comprises a controller that controls the position changing device, The controller is configured to: move either the rotating inertial body or the arm portion in the vibration direction at a predetermined specified speed.

4. The vibration suppression device according to claim 1 or 2, wherein It further comprises a controller that controls the position changing device, The controller is configured to: move either the rotating inertial body or the arm portion in the vibration direction by a predetermined specified distance at each predetermined specified time.

5. The vibration suppression device according to claim 1 or 2, wherein It further comprises a controller that controls the position changing device, The controller is configured to: move either the rotating inertial body or the arm portion in the vibration direction by a predetermined specified distance each time a main cause of vibration of the drive unit occurs.

6. The vibration suppression device according to claim 1, wherein The position changing device is configured to be able to change either the rotating inertial body or the arm portion to a position where the rotating inertial body and the arm portion are non-contact, The vibration suppression device further comprises a controller that controls the position changing device, The controller is configured to: move either the rotating inertial body or the arm portion to a position where the rotating inertial body and the arm portion are non-contact when the frequency of vibration of the drive unit is a frequency equal to or higher than a predetermined specified frequency.

7. The vibration suppression device according to claim 1, wherein The rotating inertial body has a center of gravity that is offset from the rotation center axis toward the outer side in the radial direction, The vibration suppression device further includes a controller that controls the position changing device. The controller is configured to: determine a target distance between the contact point position of the rotating inertial body and the arm portion and the center of gravity position of the rotating inertial body based on the frequency of vibration of the drive unit. According to the target distance, either the rotating inertial body or the arm portion is moved.

8. The vibration suppression device according to claim 7, wherein the target distance is determined to be a distance at which the restoring force of the elastic member and the inertial force of the rotating inertial body become equal in magnitude.

9. The vibration suppression device according to claim 7 or 8, wherein the greater the frequency of vibration of the drive unit, the smaller the target distance is set.

10. The vibration suppression device according to claim 7 or 8, wherein it further includes a distance measuring unit that measures the distance between the drive unit and the support body. The controller is configured to add or subtract the difference between the actual distance measured by the distance measuring unit and a predetermined reference distance between the drive unit and the support body from the amount of movement of either the rotating inertial body or the arm portion determined according to the target distance.

11. The vibration suppression device according to claim 7 or 8, wherein the holding portion is provided on the support body. the arm portion is provided on the drive unit.

12. The vibration suppression device according to any one of claims 1, 2, 6, 7, and 8, wherein the rotating inertial body includes two rotating members that sandwich the arm portion in a direction orthogonal to the vibration direction.

13. The vibration suppression device according to any one of claims 1, 2, 6, 7, and 8, wherein the holding portion includes a support arm, one end of the support arm is connected to one of the drive unit and the support body, and the rotating inertial body is supported at the other end of the support arm so as to be rotatable.

14. The vibration suppression device according to claim 13, wherein the position changing device is configured to move the support arm in the vibration direction.

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