JP2006090530A - Vibration control device for rotary shaft - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vibration control device for a rotary shaft having a structure capable of sufficiently ensuring durability performance of a mass-spring system and suppressing vibration in the direction of rotation in the rotary shaft over a wide scope from a low frequency band to a high frequency band advantageously. <P>SOLUTION: A mass member 16 is displaced onto an outer peripheral side and is abutted on an abutting supporting part 32 through an abutting rubber elastic body 46 based on elastic deformation of a connection rubber elastic body 18 caused by centrifugal force exerted on the mass member 16 in a rotation condition of at least a supporting member 20 in which it rotates faster than predetermined speed to let the mass member 16 supported elastically in cooperation of the connection rubber elastic body 18 and the abutting rubber elastic body 46 by the supporting member 20. By utilizing increase of amount of compression deformation of the abutting rubber elastic body 46 in accordance with increase of rotation speed of the supporting member 20, tuning frequency in the direction of rotation in an auxiliary vibration system 60 is gradually changed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vibration damping device for a rotary shaft that is mounted on a rotary shaft such as a crankshaft of an internal combustion engine and can exhibit a damping effect against vibrations in the rotational direction of the rotary shaft caused by torque fluctuations of the internal combustion engine. It is about.

  Conventionally, vibrations in the rotational direction may be a problem with a rotating shaft in various devices. For example, in an automobile equipped with an internal combustion engine as a prime mover, vibration in the rotational direction of the crankshaft resulting from torque fluctuations of the internal combustion engine is transmitted to the vehicle body via the vibration isolation mount of the power unit. It tends to cause noise.

  Therefore, in order to suppress vibration in the rotational direction of the crankshaft (torsional vibration) in an internal combustion engine, a torsional damper has been proposed as a vibration damping device having a secondary vibration system. For example, the one described in Japanese Patent Application Laid-Open No. 2004-144248 (Patent Document 1) is provided, and an annular damper mass is arranged on the outer peripheral side of the hub attached to the rotating shaft, and the annular damper mass is used as the hub. On the other hand, a sub-vibration system is configured by elastic connection with a rubber elastic body.

  In general, the torsional damper is adapted to suppress the occurrence of vibration due to the torsional resonance of the crankshaft by tuning the sub vibration system to the natural frequency in the torsional direction of the crankshaft. Here, the natural frequency of the crankshaft is generally set to several hundred Hz or more.

  However, as a result of the inventor's repeated experiments and examinations regarding automobiles equipped with an internal combustion engine as a power source, vibrations of about 20 to 70 Hz that occur when the engine speed is relatively low, such as when the automobile starts, It was found that the vibration in the rotational direction of the crankshaft was a major cause. In addition, it is considered that the vibration of the crankshaft in such a low frequency range is caused by torque fluctuation in the internal combustion engine.

  In order to reduce the rotational vibration of the crankshaft in such a low frequency range, for example, the torsional damper as described above is employed, and the natural frequency of the secondary vibration system is tuned to a low frequency range of 20 to 70 Hz. It is also possible. However, since the annular damper mass is in the shape of a large-diameter annular block, it is relatively heavy, and in order to tune to a low frequency range, it is necessary to make the rubber elastic body a low dynamic spring. When trying to tune to the frequency range, the rubber elastic body becomes too soft, and there is a problem that practical durability is hardly secured.

  In addition, since the crankshaft is rotated with the combustion stroke of each cylinder in the internal combustion engine, when the rotation speed of the crankshaft increases, the time interval at which combustion sequentially occurs in each cylinder decreases and the wavelength of torque fluctuations increases. Accordingly, the vibration frequency in the torsional direction may increase in proportion to the rotational speed. As a result, the sub-vibration system with the conventional structure tuned to the predetermined frequency range cannot cope with the change in the vibration frequency in the torsional direction due to the change in the rotation speed, so the desired vibration control effect is obtained. There was an inherent problem that it was difficult to be.

  Note that Japanese Utility Model Publication No. 6-73497 (Patent Document 2) employs a rectangular block-shaped mass member that is partially positioned on the circumference of the rotation shaft, and elastically supports both circumferential ends of the mass member. A sub-vibration system constructed in a way is disclosed. However, such a secondary vibration system is only proposed for the purpose of vibration isolation in the direction perpendicular to the axis of rotation, and is not capable of realizing an effective secondary vibration system for vibration in the low frequency range in the circumferential direction. ,never.

  Since the mass member is partially positioned independently on the circumference of the rotation shaft, a considerable centrifugal force acts on the mass member as the rotation shaft rotates. On the other hand, as suggested, in the secondary vibration system that employs a connected rubber elastic body that compresses / tensiles when the circumferential rotational vibration is input, if the circumferential natural frequency is tuned to a low frequency range, It is necessary to make the rubber elastic body considerably soft. Therefore, when the rotating shaft rotates at medium to high speed, the elastic deformation amount of the connecting rubber elastic body is considerably increased by the centrifugal force acting on the mass member, and the required durability and the like can be realized. This is because it becomes extremely difficult.

  Japanese Patent Application Laid-Open No. 2001-153185 (Patent Document 3) proposes a dynamic damper having a rolling mass. However, the dynamic damper of such a rolling mass is different from the dynamic damper described in the above-mentioned Patent Document 1 using a mass-spring secondary vibration system composed of a mass mass and a rubber elastic body in the basic structure. It is different. In such a dynamic damper using a rolling mass, it is difficult to obtain a significant damping effect in a specific frequency range as much as a dynamic damper using a mass-spring system composed of a mass mass and a rubber elastic body as described above. . In addition, it is difficult to maintain the mass rolling conditions such as the frictional resistance and surface roughness of the mass rolling surface with high accuracy over a long period of time, and the stability and reliability of the desired damping effect can be reduced. There is also a problem that it is difficult to obtain.

JP 2004-144248 A Japanese Utility Model Publication No. 6-73497 JP 2001-153185 A

  Here, the present invention has been made in the background as described above, and the problem to be solved is that the durability performance of the mass-spring system is sufficiently secured and the crankshaft of the internal combustion engine It is an object of the present invention to provide a vibration damping device for a rotating shaft having a novel structure in which vibrations in the rotational direction of the rotating shaft can be advantageously suppressed over a wide range from a low frequency region to a high frequency region.

  Hereinafter, the aspect of this invention made | formed in order to solve such a subject is described. In addition, the component employ | adopted in each aspect as described below is employable by arbitrary combinations as much as possible. Further, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or an invention that can be understood by those skilled in the art from those descriptions. It should be understood that it is recognized based on thought.

(Aspect 1 of the present invention relating to a vibration damping device for a rotating shaft)
A feature of the aspect 1 of the present invention relating to the vibration damping device for the rotating shaft is that the mass member is separated from the supporting member that is attached to the rotating shaft to be controlled and is rotated integrally with the rotating shaft. In the vibration damping device for a rotating shaft, wherein the mass member is arranged and supported by a connecting rubber elastic body with respect to the support member, thereby constituting a sub-vibration system for the rotational vibration of the rotating shaft. Is formed in a block shape that can be partially and independently positioned on the circumference around the rotation center axis of the support member, and is disposed at a position away from the rotation center axis of the support member and accompanying the rotation of the support member While a centrifugal force is applied to the mass member, the support member is provided with an abutment support portion that is spaced apart from the mass member on the outer peripheral side of the rotation shaft, and abuts against the mass member. Opposite surface of support part The mass member is provided on the basis of elastic deformation of the connecting rubber elastic body by a centrifugal force exerted on the mass member at least at a rotational speed of a predetermined speed or more of the support member by providing a contact rubber elastic body on at least one side Is displaced to the outer peripheral side and is brought into contact with the corresponding contact support portion via the corresponding rubber contact elastic body, so that the mass member is connected to the support rubber elastic member and the corresponding rubber contact elasticity. The rotation in the auxiliary vibration system is performed by utilizing the fact that the amount of compressive deformation of the corresponding rubber elastic body increases as the rotational speed of the support member increases, and is elastically supported by the body. The rotary shaft damping device is configured to gradually change the tuning frequency of the direction.

  In the rotary shaft damping device structured according to this aspect, when vibration in the rotational direction is input to the support member, the mass member and the connected rubber elastic body constitute a mass-spring system, and the damping is performed. The vibration effect is demonstrated. Further, the mass member is brought into contact with the abutting support portion via the abutting rubber elastic body, whereby the amount of outward displacement of the mass member is limited, and the mass member is supported to support the mass member. The amount of displacement of the rubber elastic body is also limited. Therefore, the rubber elastic body can be tuned with a large degree of freedom while ensuring the durability of the connected rubber elastic body. Tuning to an easy low frequency range is also possible, and a vibration damping device in the direction of rotation in the low frequency range is advantageously realized.

  In addition, when the mass member is in contact with the contact support portion via the contact rubber elastic body, if the rotation speed of the support member (rotating shaft) increases and a large centrifugal force is applied to the mass member, the mass member The displacement amount toward the outer peripheral side of the member increases, and accordingly, the elastic deformation amount (compression amount) of the contact rubber elastic body disposed between the mass member and the contact support portion increases. As a result, the natural frequency in the rotational direction of the sub-vibration system can be tuned by utilizing the fact that the spring constant of the rubber increases as the rotational speed of the support member increases. Further, there is an advantage that the durability of the contact rubber elastic body is sufficiently ensured and the contact sound of the mass member against the contact support portion is reduced.

  Further, in the form in which the mass member is abutted and supported by the abutting support portion via the abutting rubber elastic body based on the elastic deformation of the coupled rubber elastic body, the secondary vibration system in the rotation direction is connected to the mass member and the coupled rubber elasticity. In addition to the body, it includes a contact rubber elastic body. As a result, the degree of freedom in tuning the natural frequency is increased as compared with a sub-vibration system having a conventional structure in which a mass is simply connected to a housing or the like with a rubber elastic body.

  Therefore, when the frequency of the vibration in question increases as the number of rotations of the support member increases, resonance occurs based on the advantageous adjustment of the natural frequency of the secondary vibration system to the frequency range of the vibration. The action is advantageously exerted, and vibration in a high frequency region under a region where the rotational speed is relatively high can be effectively reduced.

  In short, in the vibration damping device of the present aspect, over a wide rotational speed range, specifically, for example, in an internal combustion engine having a crankshaft as a rotating shaft, it is regularly used from a low rotational speed range of the shaft in an idling state. The vibration damping effect by one vibration damping device can be advantageously exhibited over the rotation range and further over the high rotation range.

(Aspect 2 of the present invention relating to a vibration damping device for a rotating shaft)
A feature of the second aspect of the present invention relating to the vibration damping device for the rotating shaft is that, in the vibration damping device for the rotating shaft according to the first aspect of the present invention, the mass member faces the inner peripheral side of the rotating shaft. An inner abutment support portion is provided on the support member, and the mass member is abutted against and supported by the inner abutment support portion based on the elasticity of the connecting rubber elastic body, while the support member rotates. Along with this, due to the centrifugal force exerted on the mass member, the mass member is displaced to the outer peripheral side based on the elastic deformation of the connecting rubber elastic body so as to be separated from the inner contact support portion. .

  In such a mode, the contact force against the inner contact support portion of the mass member based on the elasticity of the connecting rubber elastic body is less than the centrifugal force accompanying the rotation of the support member in a static state where the support member is not rotating. In the large state, the mass member is supported in contact with the inner contact support portion. Therefore, in such a state, the displacement amount of the mass member is limited, and the hitting sound due to the mass member repeatedly hitting the support member is effectively suppressed.

(Aspect 3 of the present invention relating to a vibration damping device for a rotating shaft)
A feature of aspect 3 of the present invention relating to a vibration damping device for a rotating shaft is that, in the vibration damping device for a rotating shaft according to aspect 2 of the present invention, the support member is a crankshaft of an internal combustion engine as the rotating shaft. At least in the low rotation region of the crankshaft in the idling state of the internal combustion engine, the mass member is positioned away from the inner abutting support portion on the outer peripheral side so as to vibrate in the rotational direction. The mass member is connected to the abutting support portion via the abutting rubber elastic body at least in the high rotation region of the crankshaft exceeding the normal range of the internal combustion engine. In other words, it can function as a secondary vibration system for rotational vibration.

  In this embodiment, since the mass member can function as a secondary vibration system for the vibration in the rotational direction at least in the low rotation region of the crankshaft in the idling state, the damping effect on the vibration in the region is advantageous. To be demonstrated.

  In addition, at least in the high rotation region of the crankshaft exceeding the normal range of the internal combustion engine, the mass member is brought into contact with the contact support portion via the contact rubber elastic body by the action of the centrifugal force by utilizing the centrifugal force. Abuts stably. As a result, the amount of elastic deformation of the connected rubber elastic body is effectively limited, and the durability performance is exhibited more advantageously. In addition, it is avoided that the mass member is repeatedly brought into contact with the contact support portion under the high rotation region of the crankshaft, thereby reducing the hitting sound and vibration caused by the repeated contact.

(Aspect 4 of the present invention relating to a vibration damping device for a rotating shaft)
A feature of the aspect 4 of the present invention relating to the vibration damping device for the rotating shaft is that in the vibration damping device for the rotating shaft according to the aspect 3 of the present invention, the crankshaft is rotated at a low speed at least in an idling state of the internal combustion engine. In the region, the natural frequency of the secondary vibration system including the mass member and the connecting rubber elastic body is tuned to a low frequency region corresponding to the period of torque fluctuation of the internal combustion engine, and at least the internal combustion engine In the high rotation region of the crankshaft that exceeds the normal range, the natural frequency of the secondary vibration system including the mass member, the connecting rubber elastic body, and the contact rubber elastic body is the period of torque fluctuation of the internal combustion engine. It is tuned to the corresponding high frequency range.

  In this aspect, the natural frequency of the sub-vibration system in the low rotation range is tuned to a low frequency range corresponding to the torque fluctuation cycle of the internal combustion engine. Vibration that is a problem in the frequency range is more effectively suppressed.

  Also, in the high rotation region of the crankshaft, the natural frequency of the secondary vibration system is tuned to a high frequency region corresponding to the cycle of torque variation, which is a problem in the high frequency region considered to be caused by torque variation. The effect of reducing the vibration is advantageously exhibited. Therefore, the target vibration damping effect can be further improved.

  In this embodiment, the period of torque fluctuation of the internal combustion engine is a time interval of rotational torque fluctuation exerted on the crankshaft by the sequential generation of combustion in each cylinder of the internal combustion engine. If it exists, it corresponds to the rotation secondary component of the crankshaft, and in the case of a 6-cylinder engine, it means a cycle generated with a frequency corresponding to the rotation tertiary component of the crankshaft.

(Aspect 5 of the present invention relating to a vibration damping device for a rotating shaft)
A feature of aspect 5 of the present invention relating to a vibration damping device for a rotating shaft is that, in the vibration damping device for a rotating shaft according to aspect 4 of the present invention, the internal combustion engine is an internal combustion engine for an automobile, and an idling state of the automobile In the above, the mass member is positioned on the outer peripheral side with respect to the inner abutting support portion, while the mass member is in contact with the abutting member in a high rotation region where the crankshaft is at least 2500 rpm. It exists in the contact state with respect to the said contact support part via a rubber elastic body.

  In such a mode, the durability performance of the connected rubber elastic body is advantageously exhibited by the mass member being reliably brought into contact with the contact support portion in a high rotation region of 2500 revolutions / minute or more. The Therefore, practicality is sufficiently exhibited as a vibration damping device attached to the crankshaft of the internal combustion engine for automobiles.

(Aspect 6 of the present invention relating to a vibration damping device for a rotating shaft)
A feature of the sixth aspect of the present invention relating to the rotational shaft damping device is that in the rotational shaft damping device according to any one of the first to fifth aspects of the present invention, the mass member is arranged around the support member. In other words, at least three of them are arranged apart from each other in the direction.

  In this aspect, the secondary vibration system can be well balanced in rotation, and as a result, the damping effect can be obtained more stably.

(Aspect 7 of the present invention relating to a vibration damping device for a rotating shaft)
A feature of the aspect 7 of the present invention relating to the vibration damping device for the rotating shaft is that, in the vibration damping device for the rotating shaft according to the aspect 6 of the present invention, the mass members positioned adjacent to each other in the circumferential direction are mutually connected. There exists a connection elastic body connected in the circumferential direction.

  In this aspect, the mass members are displaced in the substantially same phase by being connected in the circumferential direction by the connecting elastic body. Therefore, based on the fact that the displacement directions of the mass members are stabilized, the desired vibration damping effect can be obtained more stably.

(Aspect 8 of the present invention relating to a vibration damping device for a rotating shaft)
A feature of the aspect 8 of the present invention relating to the rotational shaft damping device is that in the rotational shaft damping device according to any one of the aspects 1 to 7 of the present invention, a boss portion fixed to the rotational shaft; An outer peripheral annular portion that is spaced apart from the outer peripheral side of the boss portion and extends continuously in the circumferential direction; and the boss portion and the outer periphery that extend across the axially perpendicular surfaces of the boss portion and the outer peripheral annular portion. The support member is configured with a structure having a connection portion that connects the annular portions to each other at a plurality of locations on the circumference, and the boss is interposed between the plurality of connection portions adjacent in the circumferential direction in the support member. Forming a hollow space between the surface and the outer circumferential annular portion facing each other in the direction perpendicular to the axis, and arranging the mass member in the hollow space, and forming an outer peripheral wall portion of the hollow space The contact support portion is constituted by the outer peripheral annular portion.

  In this aspect, the contact support portion and the support member are integrally formed, and the manufacture becomes easy. In addition, since the contact support portion is supported by the support member via the connecting portion, a member for separately supporting the contact support portion is reduced or omitted, which simplifies the overall structure and reduces the rotation shaft. The simplification of the mounting operation can be advantageously achieved.

(Aspect 9 of the present invention relating to a vibration damping device for a rotating shaft)
A feature of the ninth aspect of the present invention relating to the vibration damping device for the rotating shaft is that in the vibration damping device for the rotating shaft according to the eighth aspect of the present invention, the mass relative to the hollow space of the support member. The member is disposed in the accommodated state, and the support member is provided with a lid portion that covers the hollow space in which the mass member is accommodated from both axial sides.

  In this aspect, the mass member is prevented from coming out of the empty space and safety is advantageously ensured.

(Aspect 10 of the present invention relating to a vibration damping device for a rotating shaft)
A feature of the tenth aspect of the present invention relating to the rotary shaft damping device is that in the rotary shaft damping device according to any one of the first to ninth aspects of the present invention, the mass member, the contact support portion, The buffer rubber is formed on at least one of the contact surfaces.

  In this embodiment, the mass member is brought into contact with the contact support portion via the buffer rubber, thereby reducing the occurrence of hitting sound.

(Aspect 11 of the present invention relating to a vibration damping device for a rotating shaft)
A feature of the aspect 11 of the present invention relating to the rotating shaft damping device is that in the rotating shaft damping device according to any one of the first to tenth aspects of the present invention, the connecting rubber elastic body is connected to the mass member. Each pair of elastic support legs extending in a substantially circumferential direction outward from each circumferential end of the circumferential direction or inclining toward the inner or outer circumferential side with respect to the circumferential direction. In the outer peripheral side of the member, there is formed an outer peripheral side space penetrating in the axial direction between the opposing surfaces in the direction perpendicular to the axis of the mass member and the support member.

  In such an aspect, the connecting rubber elastic body is constituted by a pair of elastic support legs, for example, by appropriately changing the design of the size of the elastic support legs, the inclination angle with respect to the circumferential direction, etc. Tuning changes such as spring characteristics and the natural frequency of the secondary vibration system are realized with a greater degree of freedom.

  Note that the shape, size, structure, and the like in the outer peripheral space are appropriately set and changed according to the shape of the elastic support leg, and are not particularly limited. For example, the support member When the mass member is separated from the support member in a static state in which the mass is not rotating, the outer peripheral space is developed. The member may be brought into contact with the support member so that the outer peripheral space is crushed, or the mass member is approached / separated from the support member according to the magnitude of the centrifugal force accompanying the rotation of the support member. With the elastic deformation of the elastic support leg portion based on this, the outer peripheral space may be expanded or contracted to a predetermined size.

(Aspect 12 of the present invention relating to a vibration damping device for a rotating shaft)
The aspect 12 of the present invention relating to the rotating shaft damping device is characterized in that, in the rotating shaft damping device according to any one of the first to eleventh aspects of the present invention, the mass member is the connecting rubber elastic body. The integrated vulcanized molded product to which is attached is a separate member from the support member, and the integrated vulcanized molded product is assembled to the support member.

  In such an embodiment, the integrally vulcanized molded product of the connected rubber elastic body can be miniaturized and the molding die can be small, so that the molding operation and the molding equipment are simplified.

  Moreover, this aspect is advantageously employ | adopted in combination with the said aspect 8 of this invention, for example. That is, for example, an integrally vulcanized molded product of a connected rubber elastic body provided with a mass member is fitted into the hollow space of the support member according to the aspect 8, and the mass member is brought into contact based on the elasticity of the rubber elastic body. Attaching and fixing to the support part, fixing a fixing bracket to the outer peripheral surface of the connecting rubber elastic body in the integrally vulcanized molded product, and fixing the fixing bracket to the support member with press fitting, welding, bolts, etc. Thus, after the support member and the mass member are separately formed, they can be connected to each other with a connecting rubber elastic body.

(Aspect 13 of the present invention relating to a vibration damping device for a rotating shaft)
The aspect 13 of the present invention relating to the rotational shaft damping device is characterized in that, in the rotational shaft damping device according to any one of the above aspects 1 to 12, the boss portion fixed to the rotational shaft. In contrast, the support member is configured by integrally forming the outer peripheral annular portion that is separated from the outer peripheral side of the boss portion and continuously extends in the circumferential direction, and the boss portion and the outer periphery are configured. The mass member is disposed between the opposed surfaces of the annular portion in the direction perpendicular to the axis, and the abutment support portion is formed by the outer circumferential annular portion, while being separated from the outer circumferential side of the outer circumferential annular portion. A torsional damper is provided by disposing an annular outer peripheral mass member on the same central axis as the support member and elastically connecting the outer peripheral mass member to the outer peripheral annular portion by an outer peripheral connection rubber. The outer side secondary vibration system acting as Lies in that it has.

  In such a mode, the sub-vibration system including the outer peripheral sub-vibration system and the mass member, the connecting rubber elastic body, or the contact rubber elastic body is used in combination, so that a plurality of sub-vibration systems can be obtained. Composed. Therefore, by tuning the natural frequency of these sub-vibration systems separately, a damping effect is advantageously exhibited with respect to vibrations in a plurality of or a wide frequency range.

(The present invention related to a method of manufacturing a vibration damping device for a rotating shaft)
A feature of the present invention relating to a method for manufacturing a rotating shaft damping device is that the rotating shaft damping device according to any one of the first to thirteenth aspects of the present invention is fixed to the rotating shaft. The boss portion, the outer peripheral annular portion that extends continuously in the circumferential direction and is spaced apart on the outer peripheral side of the boss portion, and extends across the axially orthogonal facing surfaces of the boss portion and the outer peripheral annular portion, The support member is configured with a structure having a boss portion and a connection portion that connects the outer peripheral annular portion to each other, and the connection portion of the support member between the boss portion and the axially opposed surface of the outer peripheral annular portion. And forming the abutting support portion by the outer peripheral annular portion constituting the outer peripheral wall portion of the thinned void, and forming the mass member as the connecting rubber. Formed separately from the support member as an integral vulcanized molded product with an elastic body Then, by fitting and fixing the integrally vulcanized molded product in the hollow space, the contact support portion is positioned opposite to the mass member on the outer peripheral side of the rotary shaft, and the mass member is abutted against the mass member. In the manufacturing method of the vibration damping device for a rotating shaft, the abutting rubber elastic body is fixed to at least one of the opposing surfaces of the contact support portion.

  According to such a method of the present invention, by integrally forming an integrally vulcanized molded product of a connected rubber elastic body having a mass member and a support member, molding equipment including a mold and the like can be simplified. It is easy to manufacture.

  As is clear from the above description, in the vibration damping device for a rotating shaft structured according to the present invention, the amount of compressive deformation of the abutting rubber elastic body abutting on the mass member as the rotational speed of the support member increases. It is possible to gradually change the tuning frequency in the rotational direction in the sub-vibration system by utilizing the increase in the frequency. Therefore, even when the frequency range of the vibration in question changes with the change in the rotation speed of the support member, the resonance action can function effectively, and it can be applied to a plurality of vibrations in a wide frequency range. The vibration control effect of the period can be obtained stably.

  Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described. 1 and 2 show a crankshaft damper 10 as a first embodiment of the present invention. The damper 10 has a structure in which a metal mass 16 is accommodated in an accommodation space 14 provided in the housing 12, and the housing 12 and the metal mass 16 are connected to each other by a connecting rubber elastic body 18. It is attached to the crankshaft by being fixed to the crankshaft of an internal combustion engine for automobiles that does not rotate.

More specifically, the housing 12 includes a housing body 20 as a support member. The housing body 20 has a thick, substantially disk shape, and a circular fitting hole 22 extending in the axial direction (left and right in FIG. 2) is provided in the center thereof. In particular, in the present embodiment, a fixing sleeve 24 having a thin and long cylindrical shape is fixed to the fitting hole 22 by press-fitting or the like. Further, both end portions in the axial direction of the fixing sleeve 24 are protruded from the both ends of the fitting hole 22 in the axial direction outward by a predetermined length. The housing body 20 is formed of a rigid material having an elastic modulus of 5 × 10 ⁴ MPa or more, and for example, a housing formed of an aluminum alloy or a steel material is suitably employed.

  Further, around the central axis 26 of the housing body 20, a plurality of through holes 28 (four in this embodiment) are provided at substantially equal intervals in the circumferential direction. The through-hole 28 extends in the axial direction with a substantially planar fan shape whose arc length increases outward in the direction perpendicular to the axis, and extends in parallel with the central axis 26 of the housing body 20. As a result, four accommodation cavities 14 are formed independently of each through-hole 28 as the hollow cavities opened at both axial ends of the housing body 20. As is clear from this, in the present embodiment, the housing cavities 14 having the same shape are formed at substantially equal intervals in the circumferential direction of the housing body 20, so that the center of gravity of the housing body 20 is located on the central axis 26. The rotation balance is set so that it is positioned at the position.

  In addition, since a plurality of the accommodation cavities 14 as described above are formed in the housing main body 20, the central portion of the housing main body 20 is formed as a small-diameter cylindrical boss portion 30 having a fitting hole 22. . Further, an outer cylinder portion 32 having a large-diameter cylindrical shape as an outer peripheral annular portion is located at a distance from the boss portion 30 outward in the direction perpendicular to the axis with the accommodation cavities 14 interposed therebetween. The boss portion 30 and the outer cylinder portion 32 are arranged so as to surround the central axis 26 of the housing body 20 substantially concentrically, and in the radial direction of the housing body 20 between the circumferential directions of the housing spaces 14. They are connected to each other at a plurality of locations on the circumference by a plurality (four in this embodiment) of connecting portions 34 extending in the direction perpendicular to the axis. That is, the outer cylinder part 32 which is spaced apart from the outer peripheral side of the boss part 30 and continuously extends in the circumferential direction is integrally formed with the boss part 30 fixed to the crankshaft described later. The housing body 20 includes a boss portion 30, an outer cylinder portion 32, and a connecting portion 34 that connects the boss portion 30 and the outer cylinder portion 32.

  Further, lid bodies 36 as lid portions are respectively disposed on both end surfaces in the axial direction of the housing body 20. The lid body 36 has a thin and substantially disk shape, and a circular insertion hole 38 is provided in the center. Then, both end portions of the fixing sleeve 24 projected from the housing body 20 are inserted into the insertion holes 38 of the respective lid bodies 36, and the lid bodies 36 are overlapped with the axial end surfaces of the housing body 20. It is fixed with bolts or welding. Accordingly, the pair of lids 36 and 36 are assembled to the housing main body 20, and the respective accommodation cavities 14 are covered from both sides in the axial direction (left and right in FIG. 2). The lid body 36 may be fixed to the housing body 20 by, for example, the fixing sleeve 24 being press-fitted and fixed to a rib protruding from the edge of the insertion hole 38.

  Further, a contact rubber 42 protruding toward the inside of the housing space 14 is provided on the outer peripheral surface 40 that is opposed to the outer cylinder portion 32 in the direction perpendicular to the axis with the housing space 14 in the boss part 30 interposed therebetween. It is fixed along the outer peripheral surface 40.

  Furthermore, the outer cylindrical portion 32 has an inner circumferential surface 44 positioned opposite to the boss portion 30 in the direction perpendicular to the axis with the accommodation space 14 interposed therebetween, and protrudes toward the accommodation space 14. A rubber contact elastic body 46 is fixed along the inner peripheral surface 44. The contact rubber 42 and the contact rubber elastic body 46 are formed using various known rubber materials such as natural rubber, isoprene rubber, butadiene rubber, and styrene rubber, and are integrally vulcanized with the housing body 20. Thus, it is configured as an integrally vulcanized molded product. The contact rubber 42 and the contact rubber elastic body 46 may be fixed to the boss portion 30 and the outer cylinder portion 32 with an adhesive or the like after being formed separately from the housing body 20, for example. .

  Further, in each accommodation space 14, an integral vulcanized molded product 48 of the connecting rubber elastic body 18 provided with the metal mass 16 and the like is disposed. The metal mass 16 as the mass member is formed of a high specific gravity material such as steel, and has a solid arc-like block shape in a plan view. Further, the curvature of the inner peripheral surface 50 of the metal mass 16 is substantially the same as the curvature of the outer peripheral surface 40 of the boss portion 30 to which the contact rubber 42 is attached. Furthermore, the curvature of the outer peripheral surface 52 of the metal mass 16 is substantially the same as the curvature of the inner peripheral surface 44 of the outer cylinder portion 32 to which the contact rubber 42 is attached.

  The connecting rubber elastic body 18 is formed by using various known rubber materials such as natural rubber, isoprene rubber, butadiene rubber, styrene rubber and the like, and includes a pair of elastic support legs 54 and 54. ing. The elastic support legs 54 extend substantially along the circumferential direction on both sides in the circumferential direction of the metal mass 16, and one circumferential end thereof is vulcanized and bonded to each circumferential end of the metal mass 16. A fixing metal fitting 56 is vulcanized and bonded to the other end in the circumferential direction of the elastic support leg 54. The fixing bracket 56 has a substantially square shape that is convex outward in the circumferential direction, and extends in a predetermined length in the axial direction (left and right in FIG. 2) with a substantially constant cross-sectional shape. . Accordingly, the integrally vulcanized molded product 48 according to the present embodiment is configured by integrally vulcanizing and molding the pair of elastic support legs 54 and 54 together with the metal mass 16 and the pair of fixing brackets 56 and 56. .

  Further, a thin rubber elastic body layer 58 as a buffer rubber is applied to the inner peripheral surface 50 and the outer peripheral surface 52 of the metal mass 16 over substantially the whole. The rubber elastic body layer 58 is integrally formed with the connecting rubber elastic body 18. Further, the Shore D hardness of the rubber elastic body layer 58 is not particularly limited, but is preferably 80 or less in consideration of effectively reducing the contact sound of the metal mass 16 to the housing 12. More preferably, it is set to 20-40.

  Then, a pair of fixing metal fittings 56 and 56 in each integrally vulcanized molded product 48 are press-fitted into the respective accommodation cavities 14, and the connecting portion 34 and the outer constituting the circumferential ends on the radially outer side of the accommodation cavities 14. It is fixed to the connecting portion of the cylindrical portion 32. That is, a plurality (four in this embodiment) of the integrally vulcanized molded product 48 is assembled in each housing space 14 of the housing body 20. As a result, the metal mass 16 and the housing body 20 are elastically connected to each other by the connecting rubber elastic body 18 including the pair of elastic support legs 54, 54. Also, the four sub-vibration systems 60 with respect to the rotational vibration, which are composed of the metal mass 16 and the connecting rubber elastic body 18, are independently provided on the circumference around the central axis 26 of the housing body 20, and are substantially equally spaced in the circumferential direction. It is arranged. Each elastic support leg 54 extends from the end of the metal mass 16 so as to go outward in the direction perpendicular to the axis as it goes outward in the circumferential direction. It is slightly inclined to extend to the side.

  Further, in a static state in which the integrally vulcanized molded product 48 is assembled to the housing 12, the inner peripheral surface 50 of the metal mass 16 has the rubber elastic body layer 58 based on the elasticity of the pair of elastic support legs 54, 54. And abutting rubber 42 fixed to the boss 30 via the boss 30. Further, the outer peripheral surface 52 of the metal mass 16 and the contact rubber elastic body 46 fixed to the outer cylinder portion 32 based on the elasticity of the pair of elastic support legs 54, 54 and the axis perpendicular direction (the radial direction of the housing 12). Are opposed to each other at a predetermined distance. As apparent from this, on the outer peripheral side of the metal mass 16, the outer peripheral side space 62 penetrating in the axial direction between the opposing surfaces of the metal mass 16 and the housing main body 20 in the axially perpendicular direction is provided. The elastic support legs 54, 54 and the outer cylinder part 32 to which the abutting rubber elastic body 46 is fixed are formed between opposite surfaces in the direction perpendicular to the axis.

  The crankshaft damper 10 having such a structure is attached to the end of the crankshaft or the like by press-fitting and fixing the crankshaft in the internal combustion engine for automobiles (not shown) to the fixing sleeve 24 of the housing 12. It has become. Further, the center axis 26 of the housing 12 and the rotation center axis of the crankshaft are positioned on the same line, and the housing 12 is rotated integrally with the crankshaft. Therefore, the secondary vibration system 60 with respect to the vibration in the rotational direction of the crankshaft is independently arranged on the circumference around the central axis 26 of the crankshaft (housing 12) at substantially equal intervals in the rotational direction.

  Further, since each metal mass 16 is positioned at a position off the central axis 26, a centrifugal force accompanying the rotation of the housing 12 is exerted on each metal mass 16. That is, as shown in FIG. 3, when the housing 12 rotates integrally with the crankshaft and a centrifugal force of a predetermined magnitude is applied to each metal mass 16, each metal mass 16 is paired. Based on the elastic deformation of the elastic support legs 54, 54, the contact rubber 42 attached to the boss 30 is separated from the outer peripheral side.

  By the way, when the engine is started or when the engine is started and the rotation speed of the crankshaft is relatively low, a large vibration may be shockedly input due to torque fluctuation. Therefore, under the low rotation region of the crankshaft to which such vibration is input, the metal mass 16 is connected and supported by the boss portion 30 of the housing body 20 based on the elasticity of the connection rubber elastic body 18. The spring of the rubber elastic body 18 is tuned. That is, in a state where such a shocking and large vibration is input (for example, the state shown in FIGS. 1 and 2), the acting force that abuts and supports the metal mass 16 on the boss portion 30 based on the elasticity of the connecting rubber elastic body 18. However, the metal mass 16 is set to be larger than the acting force that separates the metal mass 16 from the contact rubber 42 (the boss portion 30) based on the elastic deformation of the connecting rubber elastic body 18 due to the centrifugal force accompanying the rotation of the housing 12. Yes. As a result, at the time of the vibration input, the metal mass 16 is brought into contact with the boss portion 30 via the rubber elastic body layer 58 and the contact rubber 42, and the displacement amount of the metal mass 16 is limited. .

  Further, in the low rotation region of the crankshaft in the idling state of the automobile, a torsional vibration that is a problem may be caused in a low frequency region of about 20 to 70 Hz that substantially corresponds to the cycle of engine torque fluctuation. Therefore, particularly in the present embodiment, a resonance phenomenon that is effective in the sub-vibration system 60 is generated with respect to vibrations in a low frequency range where the natural frequency in the rotation direction of each sub-vibration system 60 is about 20 to 70 Hz. So all are tuned the same. That is, the natural frequency of the secondary vibration system 60 is set to a low frequency region that substantially corresponds to the period of torque fluctuation in the low rotation region of the crankshaft.

  As a result, at least in the idling state of the automobile (for example, the state shown in FIG. 3), the metal mass 16 is displaced outward in the direction perpendicular to the axis by the centrifugal force accompanying the rotation of the housing 12. Based on the elastic deformation of the portions 54, 54, the metal mass 16 is separated from the boss 30 outward in the direction perpendicular to the axis, and is positioned between the opposed surfaces of the contact rubber 42 and the contact rubber elastic body 46 in the direction perpendicular to the axis. It is supposed to be. Thus, in the sub vibration system 60 of the rotational vibration including the metal mass 16 and the pair of elastic support legs 54, 54, a resonance action is exhibited.

  Further, when the rotational speed of the housing 12 is increased and a greater centrifugal force is exerted on the metal mass 16, the metal mass 16 is further displaced outward in the direction perpendicular to the axis as shown in FIG. The metal mass 16 is brought into contact with the outer cylinder portion 32 via the contact rubber elastic body 46 based on the elasticity of the pair of elastic support legs 54, 54. It has come to be. In short, the metal mass 16 is elastically supported by the pair of elastic support legs 54 and 54 and the contact rubber elastic body 46 with respect to the outer cylindrical portion 32 of the housing body 20. As a result, the amount of displacement of the metal mass 16 outward in the direction perpendicular to the axis is limited, and the amount of elastic deformation of the pair of elastic support legs 54, 54 is also limited based on the limitation. The metal mass 16 is brought into contact with the elastic rubber body 46 based on the fact that the housing 12 continues to rotate at a predetermined rotation speed or higher, in other words, the centrifugal force of a predetermined magnitude or more continues to be exerted on the metal mass 16. The outer cylindrical portion 32 is supported in a contact state via the.

  In particular, in the present embodiment, at least in the high rotation region of the crankshaft (housing 12) of 2500 revolutions / minute or more, which exceeds the normal range of the internal combustion engine for automobiles, the metal mass 16 is placed on the outer cylinder via the contact rubber elastic body. The springs of the elastic support legs 54 and the contact rubber elastic body 46 are tuned so as to be in contact with the portion 32.

  Further, since the crankshaft is rotated in accordance with the combustion stroke of each cylinder in the internal combustion engine, when the rotation speed of the crankshaft increases, the vibration frequency substantially corresponding to the torque fluctuation period increases accordingly. Therefore, in the high rotation region (for example, the state shown in FIG. 4) of the housing 12, the amount of compressive deformation of the abutting rubber elastic body 46 disposed between the metal mass 16 and the outer cylinder portion 32 causes the rotation of the housing 12. As the speed increases, the metal mass 16 increases based on the amount of displacement outward in the direction perpendicular to the axis. In the present embodiment, the natural frequency in the rotational direction of the sub-vibration system 60 is tuned to a frequency range substantially corresponding to the period of torque fluctuation in the high rotation range of the housing 12, and the contact rubber elastic body 46 By utilizing the increase in the amount of compressive deformation, the frequency becomes large in proportion to the increase in the frequency range of the vibration that is a problem due to torque fluctuation in the high rotation range.

  In the crankshaft damper 10 having the above-described structure, for example, in a vehicle equipped with a 6-cylinder engine, a torsional vibration in a low frequency range of about 40 to 70 Hz corresponding to the third order rotation component of the crankshaft is input. In this case, each of the metal masses 16 is separated from the boss part 30 outward in the direction perpendicular to the axis, and is positioned between the opposing surfaces of the boss part 30 and the outer cylinder part 32 in the housing space 14, so that the secondary vibration is generated. It functions as a system. As a result, a damping effect can be exhibited based on the resonance action of each sub vibration system 60.

  In particular, in the present embodiment, the metal mass 16 is provided partially independently from the housing body 20 on the periphery, so that a large degree of tuning freedom is secured, and the natural vibration of each sub vibration system 60 is obtained. Since the number is tuned to the low frequency range of about 20 to 70 Hz, the resonance action is exhibited very effectively against the low frequency range vibration caused by the torque fluctuation of the crankshaft. The vibration control effect of the period can be obtained sufficiently.

  Moreover, in the high rotation region of the housing 12, the metal mass 16 is brought into contact with the outer cylinder portion 32 via the contact rubber elastic body 42 by the action of centrifugal force, and the displacement amount of the metal mass 16 is limited. Therefore, the amount of elastic deformation such as tensile deformation and shear deformation in the elastic support leg 54 is also limited. Therefore, durability is advantageously ensured even when the elastic support leg 54 is made to have a low dynamic spring in order to suppress the vibration that causes problems in the low frequency range of the sub-vibration system 60. Thereby, the desired vibration damping effect can be stably obtained.

  In this case, when the vibration frequency that becomes a problem increases as the rotational speed of the housing 12 further increases, the contact rubber elastic body 46 that is compressed and deformed between the metal mass 16 and the outer cylinder portion 32 is used. Based on the amount of deformation, the natural frequency of the secondary vibration system 60 is changed in tuning. As a result, with a single damper, it is possible to exhibit an excellent damping effect against a plurality of vibrations in a wide frequency range.

  Moreover, in this embodiment, the curvature in the inner peripheral surface 50 and the outer peripheral surface 52 of the metal mass 16 is set substantially the same as the curvature in the outer peripheral surface 40 of the boss | hub part 30, and the inner peripheral surface 44 of the outer cylinder part 32. Thus, when the surfaces are brought into contact with each other, they are stably superimposed. In addition, a rubber elastic body layer 54 is attached to the inner peripheral surface 42 of the metal mass 16, and the contact rubber 42 and the contact rubber elastic body 46 are disposed on both sides of the metal mass 16 in the direction perpendicular to the axis. As a result, in addition to further reducing noise and vibration when the metal mass 16 contacts the housing body 20 (such as the boss portion 30 and the outer cylinder portion 32), sliding friction of the metal mass 16 is increased. As a result, the contact state of the metal mass 16 with respect to the housing body 20 is further stabilized. Therefore, the stability and reliability of the desired vibration control effect are further improved.

  Further, in the present embodiment, the contact rubber 42 and the contact rubber elastic body 46 are arranged on both sides in the direction perpendicular to the axis with the metal mass 16 in between, so that vibrations other than the torsional direction are input and the metal mass 16 is input. Even if it is displaced excessively in the direction perpendicular to the axis or the like, the buffering action by the rubber is effectively functioned, and the contact sound of the metal mass 16 is effectively suppressed.

  In the present embodiment, since the structure is as described above, for example, the contact rubber 42 and the contact rubber elastic body 46 including the housing main body 12 including the boss portion 30, the outer cylinder portion 32, and the connecting portion 34. After the integral vulcanized molded product 48 and the integrally vulcanized molded product 48 of the connecting rubber elastic body 18 having the metal mass 16 and the like are separately formed, the connecting rubber elastic body 18 is integrally added to the housing space 14 of the housing body 12. A manufacturing method in which the crankshaft damper 10 is easily realized by press-fitting and fixing the sulfur molded product 48 is preferably employed.

  Next, FIG. 5 shows a crankshaft damper 70 as a second embodiment of the present invention. The second embodiment shows an aspect in which the structure and the like of the integrally vulcanized molded product of the connected rubber elastic body according to the first embodiment are different. In addition, in the following description, about the member and site | part made into the substantially same structure as said 1st embodiment, those detailed description is abbreviate | omitted by attaching | subjecting the same code | symbol in a figure.

  Specifically, the metal mass 16 according to the present embodiment is positioned in the middle portion in the direction perpendicular to the axis of the boss portion 30 and the outer cylinder portion 32 in the housing body 20. The outer peripheral surface 52 of the metal mass 16 is opposed to the contact rubber elastic body 42 attached to the inner peripheral surface 44 of the outer cylinder portion 32 with a predetermined distance in the direction perpendicular to the axis, and the metal mass 16 The inner peripheral surface 50 of the mass 16 is opposed to the outer peripheral surface 40 of the boss 30 at a predetermined distance in the direction perpendicular to the axis. A connecting rubber elastic body 18 is disposed between the metal mass 16 and the boss portion 30.

  The connected rubber elastic body 18 according to the present embodiment has an arc shape in a substantially plan view, and its outer peripheral surface is vulcanized and bonded to the inner peripheral surface 50 of the metal mass 16 and its inner peripheral surface is a boss portion. The outer peripheral surface 40 of 30 is vulcanized and bonded. Thereby, the metal mass 16 and the boss part 30 in the housing body 20 are elastically connected to each other. In the present embodiment, after the connecting rubber elastic body 18 is integrally vulcanized and molded together with the metal mass 16 and the housing body 20, the separately formed contact rubber elastic body 46 is bonded to the inner peripheral surface 44 of the outer cylinder portion 30. For example, the contact rubber elastic body 42 is integrally vulcanized and formed with the connecting rubber elastic body 18 and attached to the outer peripheral surface 52 of the metal mass 16. Of course, it is possible to form the rubber elastic bodies 18 and 46 having the mass 16 and the housing body 20 as an integrally vulcanized molded product.

  In the crankshaft damper 70 having such a structure, the metal mass 16 can function as a secondary vibration system in the rotation direction at least in the low rotation region of the crankshaft in the idling state. Similarly, low-frequency vibrations in the low rotation region are advantageously suppressed.

  When the rotation speed of the housing 12 is increased and a large centrifugal force is applied to the metal mass 16, the metal mass 16 passes through the contact rubber elastic body 46 as shown in FIG. Thus, it is brought into contact with the outer cylinder portion 32. Furthermore, the natural frequency of the secondary vibration system 60 is tuned to a high frequency range based on the fact that the rotational speed of the housing 12 increases and the amount of compressive deformation of the contact rubber elastic body 46 increases. Yes. Therefore, as in the first embodiment, an excellent damping effect is exhibited even for vibrations in a high frequency region in a high rotation region.

  In particular, in the present embodiment, the connecting rubber elastic body 18 is an integrally vulcanized molded product including the housing main body 20 and the metal mass 16, so that the number of parts can be reduced. Cost reduction and the like can be achieved.

  Next, FIGS. 7 to 8 show a crankshaft damper 80 as a third embodiment of the present invention. The present embodiment shows different aspects with respect to the housing space and the structure of the connecting rubber elastic body according to the first embodiment.

  Specifically, an annular recess 82 having a substantially circular shape in a plan view is recessed between the boss portion 30 of the housing body 20 and the outer cylinder portion 32 of the housing body 20 according to the present embodiment at a predetermined depth. It is set up. The housing 36 is sealed with respect to the external space by the cover body 36 being fixed and covered on one end surface (right side in FIG. 8) of the housing body 20 in the annular recess 82 where the annular recess 82 is opened. A void 14 is formed. In short, the accommodation space 14 of this embodiment extends continuously in the circumferential direction. Further, the boss portion 30 and the outer cylinder portion 32 are substantially connected by the other axial end portion (left in FIG. 8) of the housing body 20 on the bottom side of the annular recess 82. A connecting portion 34 that connects the boss portion 30 and the outer cylinder portion 32 includes the end portion of the housing body 20. That is, the boss part 30, the outer cylinder part 32 that extends in the circumferential direction and is separated from the outer peripheral side of the boss part 30, and the boss part that extends across the axially perpendicular surfaces of the boss part 30 and the outer cylinder part 32. The housing body 20 has a structure having a connecting portion 34 (a bottom portion of the annular recess 82) that connects the outer cylinder portion 30 and the outer cylindrical portion 32 to each other.

  In addition, a plurality of contact rubber elastic bodies 46 extending toward the accommodation space 14 are formed on the inner peripheral surface 44 that is opposed to the boss portion 30 of the outer cylinder portion 32 in the housing body 20 in the direction perpendicular to the axis (this embodiment). Are provided at a predetermined distance in the circumferential direction.

  Further, the integrally vulcanized molded article 84 of the connecting rubber elastic body 18 including the metal mass 16 according to the present embodiment is configured including the annular fixing metal fitting 86. The annular fixing fitting 86 has a substantially cylindrical shape, and its inner diameter dimension is slightly larger than the outer diameter dimension of the boss portion 30. A plurality (four in this embodiment) of metal masses 16 are arranged at a predetermined distance in the circumferential direction outside the annular fixing metal 86 in the direction perpendicular to the axis (radial direction). And opposed to each other in a direction perpendicular to the axis. The connecting rubber elastic body 18 is disposed between each metal mass 16 and the annular fixing metal fitting 86, and is vulcanized and bonded to both, whereby each metal mass 16 and the annular fixing metal fitting 86 are elastically connected to each other. ing.

  In addition, a through hole 88 extending in the axial direction is formed in an intermediate portion in the circumferential direction of the connecting rubber elastic body 18 that connects the metal mass 16 and the annular fixing metal fitting 86. Thereby, each metal mass 16 and the annular fixture 86 are connected by a pair of rubber elastic bodies substantially divided in the circumferential direction.

  Further, a connecting elastic body 90 is arranged between the metal masses 16 adjacent to each other in the circumferential direction. The connecting elastic body 90 has a substantially arc shape in a plan view, and is integrally formed with the connecting rubber elastic body 18 and the rubber elastic body layer 58. Then, both end portions in the circumferential direction of the connecting elastic body 90 are vulcanized and bonded to end portions in the circumferential direction of the respective metal masses 16 so that the respective metal masses 16 are connected to each other in the circumferential direction.

  Thus, the boss 30 of the housing body 20 is press-fitted and fixed to the annular fixing fitting 86 in the integral vulcanized molded product 84, and the integral vulcanized molded product 84 is accommodated in the annular recess 82. Further, each metal mass 16 is separated from each contact rubber elastic body 46 fixed to the inner peripheral surface 44 of the outer cylinder portion 32 in the direction perpendicular to the axis based on the elasticity of the connection rubber elastic body 18 and the connection elastic body 90. Are opposed to each other.

  In the crankshaft damper 80 structured according to the present embodiment, the metal mass 16 is at least in the low rotation region of the crankshaft in the idling state, based on the elasticity of the connecting rubber elastic body 18 and the connecting elastic body 90. By being able to function as a secondary vibration system in the rotational direction, low-frequency vibrations in the low-rotation region are advantageously suppressed as in the first embodiment.

  Further, when the rotational speed of the housing 12 is increased and a large centrifugal force is applied to the metal mass 16, the metal mass 16 is brought into contact rubber based on the elastic deformation of the connecting rubber elastic body 18 and the connecting elastic body 90. It is brought into contact with the outer cylinder portion 32 through the elastic body 46. Furthermore, the natural frequency of the secondary vibration system 60 is tuned to a high frequency range based on the fact that the rotational speed of the housing 12 increases and the amount of compressive deformation of the contact rubber elastic body 46 increases. Yes. Therefore, as in the first embodiment, an excellent damping effect is exhibited even for vibrations in a high frequency region in a high rotation region.

  In particular, in the present embodiment, the metal masses 16 are connected in the circumferential direction by the connecting elastic bodies 90, so that they are displaced in substantially the same phase, and the plurality of metal masses 16 are stabilized against torsional direction vibration. Displaced. Therefore, the desired vibration control effect can be obtained more stably.

  In addition, since both ends of each metal mass 16 are connected to another adjacent metal mass 16 by the connecting elastic body 90, one of the connecting elastic bodies 90 may be cracked or broken. Even in this case, since the metal mass 16 is connected by the other connecting elastic body 90, a so-called fail-safe effect is advantageously exhibited.

  Although the embodiments of the present invention have been described in detail above, these are merely examples, and the present invention is not limited to specific descriptions in these embodiments, and is based on the knowledge of those skilled in the art. The present invention can be implemented with various changes, modifications, improvements, and the like. Further, it goes without saying that such embodiments are all included in the scope of the present invention without departing from the gist of the present invention.

  For example, the structure of the secondary vibration system composed of the metal mass 16 and the connecting rubber elastic body 18 is not limited to the above embodiment. For example, a torsional damper integrated crankshaft damper 100 as shown in FIG. 9 may be employed. That is, in the damper 100, the annular outer peripheral mass member 102 is disposed on the same central axis as the housing body 20 and is spaced apart from the outer peripheral side of the outer cylindrical portion 32. The outer cylinder portion 32 and the outer peripheral mass member 102 are elastically connected to each other by the annular outer peripheral connecting rubber 104 disposed between the opposing surfaces of the outer peripheral mass member 102 in the direction perpendicular to the axis, thereby acting as a torsional damper. The outer sub-vibration system 106 is provided.

  As a result, by tuning the natural frequencies of the outer peripheral sub-vibration system 106 and the sub-vibration system 60, the target vibration directions and structures are different. For example, Japanese Patent Laid-Open Nos. 9-257118 and 2000-170839 are disclosed. As disclosed in Japanese Patent Laid-Open No. 5-60177, a so-called bending damper having a plurality of sub-vibration systems with respect to a rotation shaft such as a crankshaft or a drive shaft as a main vibration system is also disclosed. In substantially the same manner as the vibration damping device, a vibration damping effect is exhibited against vibrations in a plurality of or a wide frequency range.

  Further, in the first embodiment and the like, when the integral vulcanized molded product 48 of the connecting rubber elastic body 18 (the pair of elastic support legs 54 and 54) is press-fitted and fixed in the accommodation space, etc., the connecting rubber elasticity Based on the elasticity of the body 18, the contact rubber 42 fixed to the boss portion 30 may be pre-compressed, so that the durability performance of the contact rubber 42 may be largely ensured.

  Further, the lid body 36, the fixing sleeve 24, and the like according to the embodiment are provided as necessary, and are not essential members.

  Further, it is also possible to form a communication hole in the lid body 36 that covers the accommodation space 14 so that the accommodation space 14 can communicate with the external space through the communication hole. You may make it suppress a temperature rise.

  Further, in the first embodiment and the like, the integral vulcanized molded product 48 of the connecting rubber elastic body 18 provided with the metal mass 16 is provided with the fixing bracket 56 fixed to the end of the connecting rubber elastic body 18. However, for example, an annular metal fitting corresponding to the shape of the housing space 14 is provided on the outer peripheral side of the metal mass 16 so that the housing space 20 can be inserted into the housing space. A so-called cassette type fitting type that is press-fitted and fixed, or a connecting rubber elastic body 18 that does not fix the fixing metal fitting 56 is press-fitted into the accommodation space 14 and supported in the accommodation space 14 based on the elasticity of the rubber elastic body 18. If necessary, the outer peripheral surface of the connecting rubber elastic body 18 and the inner peripheral surface of the outer cylinder portion 32 constituting the wall portion of the housing space 14 are fixed to each other with an adhesive, etc. 20 It may be so as to be fixed.

  In addition, in the said embodiment, although the specific example of what this invention is applied by assembling | attaching the housing 12 prepared separately to the edge part of a crankshaft was shown, this invention is limited to this specific example. Not. For example, a housing space is formed in a main body such as a pulley or flywheel assembled on a crankshaft, a metal mass is disposed in the housing space, and the pulley or flywheel is connected to the main body by a connecting rubber elastic body. Of course, it is possible to be integrated into the same as the scope of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional explanatory view showing a crankshaft damper as a first embodiment of the present invention. It is II-II sectional drawing of FIG. FIG. 2 is a cross-sectional explanatory view showing one mode of operation of the crankshaft damper in FIG. 1 mounted on a crankshaft as a main vibration system. FIG. 8 is a cross-sectional explanatory view showing another operation mode of the crankshaft damper in FIG. 1 mounted on a crankshaft as a main vibration system. It is a cross-sectional explanatory drawing which shows the damper for crankshafts as 2nd embodiment of this invention, Comprising: It is a figure corresponding to FIG. FIG. 6 is a cross-sectional explanatory view showing one mode of operation of the crankshaft damper in FIG. 5 attached to the crankshaft as the main vibration system, corresponding to FIG. 4. It is a cross-sectional explanatory drawing which shows the damper for crankshafts as 3rd embodiment of this invention, Comprising: It is a figure corresponding to FIG. It is VIII-VIII sectional drawing of FIG. FIG. 5 is a cross-sectional explanatory view showing a crankshaft damper as another specific example of the present invention, corresponding to FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Crankshaft damper 16 Metal mass 18 Connecting rubber elastic body 20 Housing main body 26 Center shaft 32 Outer cylinder part 60 Sub vibration system

Claims (14)

A mass member is spaced apart from a support member that is attached to a rotation shaft to be controlled and rotated integrally with the rotation shaft, and the mass member is connected to the support member with a rubber elastic body connected thereto. In the vibration damping device for the rotating shaft that constitutes the secondary vibration system for the vibration in the rotational direction of the rotating shaft by connecting and supporting the rotating shaft,
The mass member is formed in a block shape that can be partially and independently positioned on the circumference around the rotation center axis of the support member, and is disposed at a position off the rotation center axis of the support member. While the centrifugal force accompanying the rotation is applied to the mass member, the support member is provided with an abutting support portion that is located on the outer circumferential side of the rotation shaft with respect to the mass member, and the mass member And a contact rubber elastic body is provided on at least one of the opposing surfaces of the contact support portion, and the connecting rubber elastic body is caused by a centrifugal force exerted on the mass member at least under a rotation state of the support member at a predetermined speed or higher. The mass member is displaced to the outer peripheral side on the basis of the elastic deformation and is brought into contact with the corresponding contact support portion via the corresponding rubber elastic body, so that the mass member is in contact with the support member. Connected rubber elastic body and corresponding contact In the sub-vibration system, the elastic body is elastically supported in cooperation with each other, and the amount of compressive deformation of the corresponding rubber elastic body increases as the rotational speed of the support member increases. A vibration damping device for a rotating shaft, wherein a tuning frequency in a rotating direction is gradually changed.   An inner abutment support portion is provided on the support member so as to be opposed to the inner peripheral side of the rotation shaft with respect to the mass member, and the mass member is moved to the inner abutment support portion based on elasticity of the connecting rubber elastic body. The mass member is displaced to the outer peripheral side due to the elastic deformation of the connecting rubber elastic body by the centrifugal force exerted on the mass member as the support member rotates. The vibration damping device for a rotating shaft according to claim 1, wherein the vibration damping device is separated from the inner contact support portion.   The support member is attached to a crankshaft of the internal combustion engine as the rotating shaft, and the mass member supports the inner abutment at least in a low rotation region of the crankshaft in the idling state of the internal combustion engine. The mass member is positioned apart from the outer peripheral side so as to function as a sub-vibration system for rotational vibration, and at least in the high rotation region of the crankshaft exceeding the normal range of the internal combustion engine. The rotary shaft control according to claim 2, wherein the rotary shaft is configured to be in contact with the contact support portion via the contact rubber elastic body and function as a sub-vibration system of rotational vibration. Shaker.   At least in the low rotation region of the crankshaft in the idling state of the internal combustion engine, the natural frequency of the secondary vibration system including the mass member and the connecting rubber elastic body corresponds to the torque fluctuation cycle of the internal combustion engine. A sub-vibration comprising the mass member, the connecting rubber elastic body, and the abutting rubber elastic body at least in the high rotation region of the crankshaft that is tuned to a low frequency range and exceeds the normal use range of the internal combustion engine. The vibration damping device for a rotating shaft according to claim 3, wherein the natural frequency of the system is tuned to a high frequency region corresponding to a period of torque fluctuation of the internal combustion engine.   The internal combustion engine is an automotive internal combustion engine, and in the idling state of the automobile, the mass member is spaced apart from the inner abutment support portion on the outer peripheral side, while the crankshaft is at least 2500 rotations. 5. The rotary shaft control according to claim 4, wherein the mass member is brought into contact with the contact support portion via the contact rubber elastic body in a high rotation region of at least 1 minute / minute. Shaker.   6. The vibration damping device for a rotating shaft according to claim 1, wherein at least three of the mass members are spaced apart from each other in the circumferential direction of the support member.   The vibration damping device for a rotating shaft according to claim 6, further comprising a connecting elastic body that connects the mass members adjacent to each other in the circumferential direction in the circumferential direction. A boss part fixed to the rotating shaft, an outer peripheral annular part that is spaced apart from the outer peripheral side of the boss part and extends continuously in the circumferential direction, and the boss part and the outer peripheral annular part straddle between the axially orthogonal facing surfaces. By configuring the support member with a structure having a connecting portion that extends and connects the boss portion and the outer peripheral annular portion to each other at a plurality of locations on the circumference,
In the support member, a hollow space is formed between the plurality of connecting portions adjacent to each other in the circumferential direction between the boss portion and the outer circumferential annular portion facing each other in a direction perpendicular to the axis, and the hollow space is formed. The rotary shaft control according to any one of claims 1 to 7, wherein the mass member is disposed on the outer circumferential wall portion, and the abutting support portion is constituted by the outer circumferential annular portion constituting the outer circumferential wall portion of the hollow space. Shaker.   The mass member is disposed in an accommodated state with respect to the hollow space of the support member, and a lid portion that covers the hollow space in which the mass member is housed from both sides in the axial direction, The vibration damping device for a rotating shaft according to claim 8 provided on the support member.   The vibration damping device for a rotating shaft according to any one of claims 1 to 9, wherein a buffer rubber is formed on at least one contact surface of the mass member and the contact support portion.   A pair of elastic supports that extend the connecting rubber elastic body from both ends in the circumferential direction of the mass member toward the outer circumferential direction in a substantially circumferential direction or inclined toward the inner or outer circumferential side with respect to the circumferential direction. The structure according to any one of claims 1 to 10, wherein an outer peripheral space is formed on the outer peripheral side of the mass member so as to penetrate between the opposed surfaces of the mass member and the support member in the axial direction in the axial direction. A vibration damping device for a rotating shaft according to claim 1.   The mass member is a separate member from the support member as an integral vulcanized molded product to which the connecting rubber elastic body is bonded, and the integral vulcanized molded product is assembled to the support member. Item 12. The vibration damping device for a rotating shaft according to any one of Items 1 to 11.   The support member is configured by integrally forming the outer peripheral annular portion that is separated from the outer peripheral side of the boss portion and continuously extends in the circumferential direction with respect to the boss portion fixed to the rotating shaft. The mass member is arranged between the boss portion and the axially orthogonal surface of the outer peripheral annular portion, and the abutment support portion is constituted by the outer peripheral annular portion. A ring-shaped outer circumferential mass member is arranged on the same central axis as the support member and is spaced apart from the outer circumferential side of the annular portion, and the outer circumferential mass member is elastically elastic with respect to the outer circumferential annular portion by the outer circumferential connecting rubber. The rotary shaft vibration damping device according to any one of claims 1 to 12, wherein an outer peripheral sub-vibration system that functions as a torsional damper is configured by connecting together. In manufacturing the vibration damping device for a rotating shaft according to any one of claims 1 to 13,
Between the boss portion fixed to the rotating shaft, the outer peripheral annular portion extending continuously in the circumferential direction at a distance to the outer peripheral side of the boss portion, and the axially perpendicular facing surfaces of the boss portion and the outer peripheral annular portion. The support member is configured with a structure having a connecting portion that extends across the boss portion and connects the outer peripheral annular portion to each other, and the boss portion and the outer peripheral annular portion between the axially orthogonal facing surfaces. Forming a hollow space at a position avoiding the connecting portion of the support member, and forming the abutting support portion by the outer peripheral annular portion constituting the outer peripheral wall portion of the hollow space; By forming the mass member separately from the support member as an integrally vulcanized molded product to which the connecting rubber elastic body is bonded, and fitting and fixing the integrally vulcanized molded product into the hollow space, The abutting support portion is positioned opposite to the mass member on the outer peripheral side of the rotating shaft, and Method of manufacturing a rotary shaft for vibration damping device, characterized in that fixedly provided the contact rubber elastic body at least one of the opposing surfaces of the Luo mass member and the abutting support portion.

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