JP2013050135A - Rotational fluctuation absorbing damper pulley - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent the occurrence of belt slipping in a rotational fluctuation absorbing damper pulley for transmitting torque while absorbing rotational fluctuation.SOLUTION: The rotational fluctuation absorbing pulley includes a hub 1 attached to a rotary shaft to be rotated integrally with the rotary shaft, a pulley 4 concentrically disposed on its outer circumferential side, an elastic body 10 integrally disposed in the inner peripheral surface of the pulley 4, a link 7 coupled with the circumferential-direction prescribed place of the hub 1 to swing, and an arm 9 coupled with the swing end of the link 7 to swing and extend in a circular arc shape toward the forward rotation side of the hub 1. In the prescribed place of the inner peripheral surface of the elastic body 10, an engaging part 10a is formed to be engaged with the tip part 9b of the arm 9 only during the delay angle difference of the pulley 4 to the hub 1, and the arm 9 is displaceable in a radial direction in the compression direction of the elastic body 10 by rocking of the link 7.

Description

  The present invention relates to a rotation fluctuation absorbing damper pulley that transmits torque from a rotation shaft such as a crankshaft of an internal combustion engine for an automobile to another rotating device via a belt and smoothes belt driving by absorbing the rotation fluctuation.

  Conventionally, as this type of damper pulley, a hub that rotates together with a crankshaft, a pulley that is arranged on the outer periphery of the hub and on which a belt is wound, and a rubber-like elastic material that connects the hub and the pulley (rubber material or rubber) An annular first elastic body made of a synthetic resin material having a ring-like elasticity and an annular second elastic body made of a rubber-like elastic material (a rubber material or a synthetic resin material having a rubber-like elasticity) on the outer periphery of the hub. There is known a structure constituted by a dynamic damper or the like having a structure in which an annular mass body is elastically and concentrically connected via a pin.

  In other words, the conventional rotational fluctuation absorbing damper pulley is driven by a dynamic damper in which an annular mass body is elastically connected to the outer periphery of the hub via a second elastic body and resonates in the circumferential direction in a predetermined frequency range. The torsional vibration of the crankshaft is reduced by the dynamic vibration absorption effect, and the driving torque input from the crankshaft to the hub is subjected to repeated rotational fluctuations (transmission torque fluctuations) due to the circumferential shear deformation action of the first elastic body. ) Is transmitted to the pulley while absorbing (see, for example, Patent Document 1 below).

  However, the conventional rotational fluctuation absorbing damper pulley is composed of a vibration system having a low resonance point (resonance frequency) by a pulley and a low-spring first elastic body elastically connected to the outer periphery of the hub. Therefore, when the rotation fluctuation of the crankshaft passes through the resonance point in the process of starting or stopping the internal combustion engine, the pulley vibrates greatly in the twisting direction (circumferential direction), and the pulley and the belt wound around the pulley The problem that slip occurs between is pointed out. Further, when a sudden torque fluctuation occurs in the normal rotation range, a similar belt slip may occur.

  The occurrence of the belt slip as described above may cause an abnormal noise called “belt squeal”, and there is a concern that the durability of the belt is reduced due to wear of the belt, causing trouble in running.

JP 2007-107637 A

  The present invention has been made in view of the above points, and its technical problem is to effectively prevent occurrence of belt slip in a rotational fluctuation absorbing damper pulley that transmits torque while absorbing rotational fluctuation. There is.

  As means for effectively solving the technical problem described above, a rotation fluctuation absorbing damper pulley according to the invention of claim 1 is provided with a hub that is attached to a rotating shaft and rotates integrally with the rotating shaft, and an outer peripheral side thereof. A pulley arranged concentrically and rotatable relative to the hub, an elastic body integrally provided on an inner peripheral surface of the pulley, and a swingable coupling at a predetermined position in the circumferential direction of the hub A link and an arm that is swingably coupled to the swing end of the link and extends toward the positive rotation side of the hub, and a retard angle of the pulley relative to the hub at a predetermined position on the inner peripheral surface of the elastic body An engaging portion that can be engaged with the tip of the arm only at the time of differential is formed, and the arm can be displaced in the radial direction in the compression direction of the elastic body by swinging the link.

  The rotational fluctuation absorbing damper pulley configured as described above is a one-way clutch that transmits torque in the forward rotation direction from the hub side to the pulley side when the pulley is differentially retarded with respect to the hub, and interrupts torque transmission when the pulley is differentially advanced with respect to the hub. In addition to forming a mechanism, the circumferential displacement of the hub and pulley due to fluctuations in transmission torque is converted as a change in the amount of compression of the elastic body by the arm that is repeatedly displaced in the radial direction by swinging the link, thereby smoothing the rotation of the pulley To do.

  In other words, when the hub starts in the forward rotation direction together with the rotating shaft, the arm is displaced to the outer diameter side by centrifugal force, and its tip slides on the inner peripheral surface of the elastic body, so that the pulley is relatively retarded relative to the hub. Since it will be in a moving state, the tip part of an arm will engage with the engaging part formed in the internal peripheral surface of an elastic body soon. For this reason, the torque in the forward rotation direction input to the hub is transmitted from the link to the elastic body via the arm, and further to the pulley, so that the pulley starts rotating. In this state, the transmission torque is displaced so that the joint between the link and the arm is broken, the arm compresses and deforms the elastic body in the radial direction, and the torque reaction force is loaded by the compression reaction force.

  In addition, when the hub is decelerated in the forward rotation, if the pulley causes an advance angle differential with respect to the hub due to the inertia on the pulley side, the tip of the arm does not engage with the engaging portion of the elastic body, and the pulley does not move between the arm and the elastic body. Since it is possible to rotate in the advance direction while sliding with the inner peripheral surface of the belt, the pulley and the belt wound around the outer periphery thereof are prevented from slipping.

  According to a second aspect of the present invention, the rotational fluctuation absorbing damper pulley includes an annular mass concentrically arranged with the hub and a mass support elastic body that elastically supports the annular mass on the hub. The torsional damper section is provided.

  In the above configuration, the torsional damper portion dynamically absorbs the torsional vibration of the rotating shaft by resonating with the input vibration in the resonance frequency range by the torsional direction inertial mass of the annular mass and the torsional direction spring constant of the mass support elastic body. It demonstrates the vibration control function.

  According to a third aspect of the present invention, in the rotation fluctuation absorbing damper pulley according to the first or second aspect of the present invention, the arm is formed in an arc shape, and its tip end engages with the engaging portion. At the same time, when the link is displaced to the outermost side due to the swing of the link, it forms an arc shape substantially concentric with the inner peripheral surface of the pulley.

  In the above configuration, the arm is displaced to the outer diameter side so as to be substantially concentric with the inner peripheral surface of the pulley by the swing of the link, so that the elastic body is compressed by the arm in a wide range in the circumferential direction. , It is possible to prevent the compressive stress from being concentrated on a part.

  According to the rotational fluctuation absorbing damper pulley according to the present invention, since the resonance system using the pulley as a mass is not configured, slip due to the resonance motion of the pulley is caused between the pulley and the belt wound around the pulley in the process of starting and stopping. The elastic body is compressed and deformed in the radial direction by the arm whose tip is engaged with the engaging part at the time of differential differential of the pulley due to fluctuation (rotational fluctuation) of the transmission torque from the hub, and the pulley advances. In the angular differential operation, torque can be transmitted from the hub to the pulley and rotational fluctuation can be absorbed by an operation in which the arm slides on the inner peripheral surface of the elastic body without being engaged with the engaging portion.

1 is a cross-sectional view showing a preferred embodiment of a rotational fluctuation absorbing damper pulley according to the present invention by cutting along a plane passing through an axis O. FIG. FIG. 2 is a cross-sectional perspective view cut along a plane orthogonal to the axis O at the position of line II-II in FIG. 1. It is a perspective view which shows preferable embodiment of the rotation fluctuation | variation absorption damper pulley which concerns on this invention in the state which removed the pulley. It is sectional drawing of a torque non-transmission state shown cut | disconnected and shown by the plane orthogonal to the axial center O in the II-II line position in FIG. It is sectional drawing of the torque transmission start state by the delay angle differential of the pulley with respect to a hub shown by cut | disconnecting in the plane orthogonal to the axial center O in the II-II line position in FIG. FIG. 2 is a cross-sectional view showing a state in which the amount of compression of an elastic body due to a differential delay of a pulley with respect to a hub is small, shown by cutting along a plane orthogonal to the axis O at the position of line II-II in FIG. FIG. 2 is a cross-sectional view showing a state where an amount of compression of an elastic body is increased by a retard angle differential of a pulley with respect to a hub, shown by cutting along a plane orthogonal to an axis O at the position of line II-II in FIG. 1. FIG. 2 is a cross-sectional view showing a state in which the amount of compression of the elastic body due to the differential differential of the pulley with respect to the hub is maximized by cutting along a plane orthogonal to the axis O at the position of line II-II in FIG. FIG. 2 is a cross-sectional view of a sliding state of an arm and an elastic body by differential advancement of a pulley with respect to a hub, shown by cutting along a plane orthogonal to an axis O at the position of line II-II in FIG. 1.

  Hereinafter, a preferred embodiment of a rotational fluctuation absorbing damper pulley according to the present invention will be described with reference to the drawings. The “front side” used in the following description is the left side in FIG. 1, that is, the front side of the vehicle, and the “rear side” is the right side in FIG. 1, that is, the side where the internal combustion engine exists. Therefore, the positive rotation direction refers to the clockwise direction in each figure except FIG.

  First, in FIG. 1, reference numeral 1 is a hub attached to a shaft end of a crankshaft (not shown) of an internal combustion engine of an automobile. The hub 1 is manufactured by casting a metal material or the like. The hub 1 is an inner cylinder portion 1a fixed to a crankshaft which is a rotating shaft, a disk portion 1b extending from the outer diameter side, and a diameter thereof. It has an intermediate cylinder part 1c protruding from the middle in the direction to the front side, and an outer cylinder part 1d extending from the outer diameter end of the disk part 1b to the back side.

  An annular mass 2 is disposed on the outer periphery of the outer cylindrical portion 1 d of the hub 1, and the annular mass 2 and the outer cylindrical portion 1 d can be relatively displaced in the torsional direction (circumferential direction) via the mass support elastic body 3. Are elastically connected to each other. The annular mass 2 is manufactured by casting a metal material having a high density (specific gravity), and the mass support elastic body 3 is a rubber-like elastic material (rubber material) excellent in heat resistance, cold resistance and mechanical strength. Or a synthetic resin material having rubber-like elasticity), which is vulcanized and formed into a ring (cylindrical shape) and press-fitted into a tortuous gap between the ring-shaped mass 2 and the outer cylindrical portion 1d.

  The annular mass 2 and the mass supporting elastic body 3 constitute a torsional damper portion TVD that dynamically absorbs the resonance in the torsional direction of the crankshaft caused by engine vibration, that is, the torsional damper portion TVD. The torsional direction resonance frequency is tuned so as to coincide with a predetermined frequency range in which the torsion angle of the crankshaft is maximized by the inertial mass of the annular mass 2 and the spring constant of the mass support elastic body 3.

  A pulley 4 is concentrically disposed on the outer peripheral side of the hub 1. The pulley 4 is manufactured by press forming, rolling, or the like of a metal plate, and is a pulley body 4a that is concentrically supported via a radial bearing 5 on the outer periphery of the annular mass 2 in the torsional damper portion TVD. And a cylindrical portion 4b extending from there to the front side, and an inward direction extending from the end of this cylindrical portion 4b to the front side of the torsional damper portion TVD (annular mass 2 and mass support elastic body 3) in the inner diameter direction. It consists of a flange 4c. A poly V groove is formed on the outer peripheral surface of the pulley main body 4a, and an endless belt (not shown) is wound around the pulley main body 4a.

  A radial bearing 5 slidably interposed between the annular mass 2 and the pulley body 4a of the pulley 4 is made of a synthetic resin material such as PTFE (polytetrafluoroethylene) having excellent sliding properties and wear resistance. It is a thing and is shape | molded by the cylindrical shape.

  As shown more clearly in FIGS. 2 and 3, on the front side of the disk portion 1 b in the hub 1, via a mounting shaft 6 implanted parallel to the axis O at a 180-degree symmetrical position in the disk portion 1 b. Each link 7 is swingably coupled, and an arm 9 is swingably coupled to a swing end of each link 7 via a link pin 8. The arm 9 extends in an arc shape from a connecting end portion 9a with the link 7 toward the forward rotation side of the hub 1 (clockwise direction in FIGS. 2 and 3).

  An elastic body 10 is integrally provided on the inner peripheral surface of the cylindrical portion 4 b in the pulley 4. This elastic body 10 is annularly vulcanized and molded with a rubber-like elastic material (rubber material or synthetic resin material having rubber-like elasticity) excellent in heat resistance, cold resistance and mechanical strength, and at the same time as molding, the cylindrical portion 4b. Are vulcanized and bonded together.

  On the inner peripheral surface of the elastic body 10, as shown in FIG. 2, an engaging portion 10 a made of a chevron-shaped protrusion and a gently raised portion 10 b to be compressed are arranged in six circumferential directions (60-degree intervals). It is formed alternately. The engaging portion 10a has a shape in which the surface on the side of the positive rotation direction (clockwise direction in FIG. 2) is a gentle slope as viewed from the top, and the surface on the opposite side is substantially cut in the radial direction. Thus, it is possible to engage with the tip 9b of the arm 9 only at the time of the differential differential of the pulley 4 with respect to the hub 1.

  Further, in the state where the swing end portion of the link 7 swinging around the mounting shaft 6 faces the outer diameter direction as shown in FIG. 8 (the state displaced to the outermost diameter side in the movable range), The swing radius of the link 7 is defined so that the connecting end portion 9a of the arm 9 displaced by the position is positioned on the outer diameter side of the engaging portion 10a and the compressed portion 10b on the inner peripheral surface of the elastic body 10. ing. The arm 9 is engaged with the engaging portion 10a at the tip end portion 9b, and in the state where the connecting end portion 9a with the link 7 is displaced to the outermost side by the swing of the link 7, The length of the two engaging portions 10a and the compressed portion 10b connected (length of about 120 degrees in the circumferential direction) forms an arc shape that is substantially concentric with the inner peripheral surface of the cylindrical portion 4b of the pulley 4. Is.

  Returning to FIG. 1, the inner pressing member 11 is attached to the outer peripheral surface of the intermediate cylindrical portion 1 c of the hub 1. This inner pressing member 11 is manufactured by press molding of a metal plate or the like, and has an outer diameter from the fitting cylinder part 11a press-fitted to the outer peripheral surface of the intermediate cylinder part 1c and the front end thereof. A flange portion 11b developed in the direction is provided, and the drop of the link 7 from the mounting shaft 6 is prevented by the flange portion 11b.

  The inward flange 4c of the pulley 4 is located on the front side of the flange portion 11b of the inner pressing member 11, and on the inner surface of the inward flange 4c facing the flange portion 11b of the inner pressing member 11 in the axial direction, A thrust spring portion 10c extending from an elastic body 10 provided on the inner periphery of the cylindrical portion 4b of the pulley 4 is integrally provided, and an inner thrust bearing 12 is integrally provided on an end surface thereof. That is, the thrust spring portion 10c is formed at the same time as the elastic body 10 is formed, and is integrally vulcanized and bonded to the inward flange 4c. The inner thrust bearing 12 is excellent in slidability and wear resistance. It is made of a synthetic resin material such as PTFE (polytetrafluoroethylene), is formed into a flat washer shape, and is in close contact with the flange portion 11b of the inner pressing member 11 so as to be slidable.

  An outer pressing member 13 is attached to the inner peripheral surface of the intermediate cylindrical portion 1 c of the hub 1. The outer pressing member 13 is manufactured by press forming of a metal plate or the like, and is externally attached from the fitting cylinder part 13a press-fitted to the inner peripheral surface of the intermediate cylinder part 1c and the front end thereof. It has a flange portion 13b developed in the radial direction. The flange portion 13b is located on the front side of the inward flange 4c of the pulley 4, and the outer thrust bearing 14 is slidable between the inward flange 4c and the flange portion 13b facing each other in the axial direction. Intervened. The outer thrust bearing 14 is made of a synthetic resin material such as PTFE (polytetrafluoroethylene) having excellent slidability and wear resistance, and is formed into a flat washer shape.

  Accordingly, the pulley 4 has an inward flange 4c whose flange portion 11b is formed by the inner pressing member 11 and the outer pressing member 13 through the thrust spring portion 10c, the inner thrust bearing 12 and the outer thrust bearing 14 of the elastic body 10. Axial displacement is regulated by being sandwiched between 13b so as to be relatively rotatable.

  The rotation fluctuation absorbing damper pulley having the above configuration transmits torque in the forward rotation direction from the hub 1 side to the pulley 4 side when the pulley 4 is retarded with respect to the hub 1, and when the pulley 4 is advanced with respect to the hub 1. A one-way clutch mechanism that cuts off torque transmission is used, and the rotation of the pulley 4 is smoothed by converting the circumferential relative displacement between the hub 1 and the pulley 4 due to rotational fluctuations as a change in the amount of radial compression of the elastic body 10. To do.

  Specifically, when the hub 1 is stopped, the tip 9b of the arm 9 is not engaged with the engaging portion 10a formed on the inner peripheral surface of the elastic body 10, as shown in FIG.

  When the hub 1 is started in the positive rotation direction (clockwise direction in FIG. 4) together with the crankshaft (not shown) by starting the internal combustion engine from this stopped state, the torque in the positive rotation direction of the hub 1 is applied to the pulley 4 at this time. Because the pulley 4 is not transmitted to the hub 1, the pulley 4 is in a retarded differential state with respect to the hub 1, so that the arm 9 that starts rotating together with the hub 1 is displaced to the outer diameter side by centrifugal force and its distal end 9 b Slides on the inner peripheral surface of the elastic body 10, and eventually engages with the raised surface of the engaging portion 10a as shown in FIG. For this reason, the torque in the forward rotation direction input to the hub 1 is transmitted from the engagement portion 10a to the elastic body 10 from the link 7 via the arm 9, and the pulley 4 integrated with the elastic body 10 starts to rotate. The

  As described above, the pulley 4 starts to rotate when the engaged state shown in FIG. 5 is reached. However, for easy understanding, the pulley 4 and the elastic body integral with the pulley 4 are shown in FIGS. 10 represents the relative operation of the hub 1, the link 7 and the arm 9, the pulley 4 and the elastic body 10 integral with the hub 1, assuming that they are in the same state (the same rotation angle) as in FIG. In addition, the triangular marks in the figure are attached for easy understanding of changes in the relative displacement amount of the hub 1 and the pulley 4.

  As shown in FIG. 5, after the distal end portion 9 b of the arm 9 is engaged with the engaging portion 10 a of the elastic body 10, the pulley 4 further moves relative to the hub 1 as the rotation of the hub 1 is accelerated. Since the retarded differential state is reached, the link 7 swings to the outer diameter side about the mounting shaft 6 by torque load, that is, the joint portion of the link 7 and the arm 9 by the link pin 8 is bent to the outer diameter side. The state is displaced, and the state shown in FIG. 6 is changed to the state shown in FIG. In the course of such an operation, the arm 9 is displaced to the outer diameter side with the engaging portion 10a as a fulcrum by the swinging and centrifugal force of the link 7. Therefore, the compressed portion 10b formed on the elastic body 10 is compressed and deformed in the radial direction by the arm 9, as shown by broken lines in FIGS. 6 and 7, and a torque reaction force is applied by the compression reaction force.

  Specifically, in the state shown in FIG. 6, each arm 9 compresses only one compressed portion 10b near the tip 9b, whereas in the state shown in FIG. 7, each arm 9 has two places. The portion to be compressed 10b and the engaging portion 10a between them are compressed, and the amount of compression by the portion near the tip portion 9b is also larger than the state shown in FIG. For this reason, the spring constant rises nonlinearly.

  FIG. 8 shows a state in which the connecting end portion 9a of the arm 9 with the link 7 is displaced to the outermost side when the swing end portion of the link 7 is directed substantially in the outer diameter direction, that is, the elastic body 10. The amount of compression is the maximum. In this state, the arm 9 is in a position that forms an arc shape substantially concentric with the inner peripheral surface of the cylindrical portion 4b of the pulley 4, and the compression of the elastic body 10 by the arm 9 is performed in a wide range in the circumferential direction. Stress is not concentrated in a part.

  Further, in the initial engagement state shown in FIG. 5, torque transmission is performed by engaging only the distal end portion 9 b of the arm 9 and the engagement portion 10 a of the elastic body 10, but thereafter the arm 9 swings the link 7. As the displacement to the outer diameter side increases due to the movement, the torque transmission force increases by increasing the contact area with the elastic body 10 and also increasing the pressure contact force, so that the load due to torque transmission is applied only to the engaging portion 10a. There is no concentration.

  And in the input of the periodic rotation fluctuation, the delay angle differential and the advance angle differential with respect to the hub 1 are repeatedly generated in the pulley 4 due to the inertia of the pulley 4 side including the belt and the auxiliary machine. As described above, the amount of compression of the elastic body 10 by the arm 9 increases in the retard angle differential of the pulley 4, and in the advance angle differential of the pulley 4, the amount of compression of the elastic body 10 by the arm 9 is reversed by the reverse operation. Decrease. That is, the repetitive circumferential relative displacement of the hub 1 and the pulley 4 due to relatively small rotational fluctuations is converted as a change in the compression amount of the elastic body 10 by the arm 9 that is repeatedly displaced in the radial direction by the swing of the link 7. As a result, smooth rotation on the pulley 4 side including the belt and auxiliary equipment is maintained.

  Further, since the relative displacement θ in the circumferential direction between the hub 1 and the pulley 4 (see FIG. 8) due to the input of such rotational fluctuation is converted as a small change in the amount of radial compression of the elastic body 10, the compression spring Nevertheless, since the spring constant in the circumferential direction can be kept low for relatively small rotational fluctuations during normal rotation, the rotational fluctuations can be absorbed well, and the load applied to the elastic body 10 can be kept small.

  Further, in the rotation region where the torsion angle is maximized by the resonance of the crankshaft, the torsional direction (circumferential direction) is opposite in phase to the rotational fluctuation to which the torsional damper portion TVD composed of the annular mass 2 and the mass support elastic body 3 is input. ), That is, the torque generated by the resonance occurs in the opposite direction to the input torque fluctuation, and therefore exhibits a dynamic vibration absorption effect that effectively reduces the peak of the crankshaft rotation fluctuation.

  Further, for example, when the rotation of the hub 1 in the positive direction is decelerated when the internal combustion engine is stopped, for example, when the pulley 4 is greatly advanced with respect to the hub 1, that is, in an overrun state, As shown in FIG. 9 from the state shown in FIG. 5, the tip 9 b of the arm 9 does not engage with the engaging portion 10 a formed on the inner peripheral surface of the elastic body 10, and the inner periphery of the arm 9 and the elastic body 10. The pulley 4 can freely rotate while sliding with the surface.

  Therefore, the slippage of the pulley 4 and the belt wound around the outer periphery of the pulley 4 is prevented by these actions, and as a result, the generation of abnormal noise called “belt squealing” due to such belt slip and the reduction of the durability of the belt are effective. Is prevented.

DESCRIPTION OF SYMBOLS 1 Hub 2 Annular mass 3 Mass support elastic body 4 Pulley 7 Link 9 Arm 9b Tip part 10 Elastic body 10a Engagement part 10b Compressed part TVD Torsional damper part

Claims (3)

  A hub that is attached to the rotation shaft and rotates integrally with the rotation shaft, a pulley that is concentrically disposed on the outer peripheral side and is rotatable relative to the hub, and an inner peripheral surface of the pulley. An elastic body, a link that is swingably coupled to a predetermined position in the circumferential direction of the hub, and an arm that is swingably coupled to the swing end of the link and extends toward the positive rotation side of the hub. And an engaging portion that can be engaged with the tip of the arm only at the time of differential differential of the pulley with respect to the hub is formed at a predetermined location on the inner peripheral surface of the elastic body. A rotational fluctuation absorbing damper pulley characterized by being capable of radial displacement in the compression direction of the elastic body by movement.   The rotation fluctuation absorbing damper pulley according to claim 1, further comprising an annular mass concentrically arranged with the hub, and a torsional damper portion comprising a mass supporting elastic body elastically supporting the annular mass on the hub. .   The arm is formed in an arc shape, and the tip end portion of the arm engages with the engaging portion and is displaced to the outermost side by the swing of the link, and the arc shape is substantially concentric with the inner peripheral surface of the pulley. The rotation fluctuation absorbing damper pulley according to claim 1 or 2, characterized in that:

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