JP2013050136A - Rotation variation absorption damper pulley - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent the occurrence of a belt slip, in a rotation variation absorption damper pulley which transmits torque while absorbing a rotation variation.SOLUTION: The rotation variation absorption damper pulley comprises: a hub 1 which is attached to a rotating shaft, and rotates integrally with the rotating shaft; the pulley 4 which is arranged concentrically with the external peripheral side of the hub, and can relatively rotate with the hub 1; a link 7 which is connected to a prescribed point of the hub 1 in the circumferential direction so as to be oscillatory, and oriented toward the forward rotation side of the hub 1 at its oscillation end; and an arm 9 which is connected to the oscillation end of the link 7 so as to be oscillatory, circularly extends to the forward rotation side of the hub 1, and is closely connected to the inner peripheral surface of the pulley 4 at its outer peripheral surface so as to be oscillatory. A friction force of the arm 9 to the inner peripheral surface of the pulley 4 is increased by the link 7 at the retardancy differentiation of the pulley 4 with respect to the hub 1, and at the advance differentiation of the pulley 4 with respect to the hub 1, the friction force of the arm 9 to the inner peripheral surface of the pulley 4 is decreased by 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 disposed concentrically and rotatable relative to the hub; a link coupled to a predetermined position in a circumferential direction of the hub so as to be swingable; and a swing end portion facing a positive rotation side of the hub; An arm that is swingably coupled to the swing end of the link and extends in an arc shape toward the positive rotation side of the hub, and has an arm whose outer peripheral surface is slidably in close contact with the inner peripheral surface of the pulley It is.

  The rotational fluctuation absorbing damper pulley configured as described above transmits torque in the forward rotation direction from the hub side to the pulley side by the frictional force of the arm against the inner peripheral surface of the pulley when the pulley is retarded with respect to the hub. In the differential operation, a one-way clutch mechanism is established in which torque transmission is interrupted by a decrease in the frictional force, and the relative displacement in the circumferential direction of the hub and pulley due to fluctuations in transmission torque is absorbed by the sliding of the arm with respect to the inner peripheral surface of the pulley. To smooth the rotation of the pulley.

  Specifically, the starting torque in the forward rotation direction input to the hub by starting the rotating shaft is transmitted from the hub to the arm via the link. At this time, the arm is given a behavior to be displaced toward the outer diameter side by the link, so that the frictional force of the arm against the inner peripheral surface of the pulley increases, thereby transmitting torque in the forward rotation direction from the arm to the pulley. And rotation of the pulley is started.

  In addition, in a situation where a relative delay angle differential and an advance angle differential with respect to the hub are repeatedly generated in the pulley due to the rotation fluctuation input from the rotation shaft to the hub, the link is externally attached to the arm during the delay angle differential. Because the behavior to give displacement to the radial side is given, the frictional force against the inner peripheral surface of the pulley increases, torque transmission to the pulley is performed while reducing the slip of the arm with respect to the inner peripheral surface of the pulley, and the advance angle difference When moving, the link gives the arm a behavior to move toward the inner diameter side, so the frictional force of the arm against the inner peripheral surface of the pulley decreases, and the pulley overrun is allowed by the slip of the arm against the inner peripheral surface of the pulley. The And by such operation | movement, rotation of a pulley is smoothed and the slip of the belt wound around the outer periphery of a pulley is prevented.

  According to a second aspect of the present invention, the rotational fluctuation absorbing damper pulley according to the first aspect is provided with a friction material having an appropriate friction coefficient on the outer peripheral portion of the arm, and the arm is an inner peripheral surface of the pulley in the friction material. Is closely related.

  According to a third aspect of the present invention, the rotation fluctuation absorbing damper pulley is provided with a spring for holding the arm in contact with the inner peripheral surface of the pulley in the configuration of the first or second aspect.

  The spring provided in the above configuration is designed to prevent the arm, which has been separated from the inner peripheral surface of the pulley when the rotation is stopped, from colliding with the inner peripheral surface of the pulley due to centrifugal force when the hub is started. Although it is held in contact with the peripheral surface, it can also have a function as means for adjusting the frictional force of the arm against the inner peripheral surface of the pulley.

  A rotational fluctuation absorbing damper pulley according to a fourth aspect of the present invention is the structure according to any one of the first to third aspects, wherein the annular mass arranged concentrically with the hub and the annular mass are elastically supported by the hub. A torsional damper portion made of a mass supporting elastic body 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 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 frictional force of the arm against the inner peripheral surface of the pulley increases when the pulley is retarded due to fluctuations in the transmission torque from the hub (rotational fluctuation). By reducing the frictional force of the arm with respect to the surface, it is possible to transmit torque from the hub to the pulley and absorb rotational fluctuations while causing the inner peripheral surface of the pulley and the arm to slide repeatedly.

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.

  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 FIG.

  In these drawings, reference numeral 1 denotes a hub attached to a shaft end of a crankshaft (not shown) of an automobile internal combustion engine. 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.

  A link 7 is slidably coupled to the front side of the disk portion 1b of the hub 1 via a mounting shaft 6 planted parallel to the axis O at a 180 degree symmetrical position. The moving end portion faces the forward rotation side of the hub 1.

  An arm 9 is slidably coupled to the swing end portion of each link 7 via a link pin 8. The arm 9 includes an arm main body 91 extending in a semicircular arc shape from a base end portion 91 a connected to the link 7 toward the positive rotation side of the hub 1, and a friction material 92 integrally joined to the outer peripheral surface thereof. Thus, the entire outer peripheral surface of the friction material 92 is in close contact with the inner peripheral surface of the cylindrical portion 4 b of the pulley 4 so as to be slidable. Therefore, in this state, the arm 9 (arm body 91 and friction material 92) has an arc shape substantially concentric with the inner peripheral surface of the cylindrical portion 4b of the pulley 4.

  The proximal end portion 91a of the arm body 91 in the arm 9 and the distal end portion 91b of the arm body 91 in the other arm 9 are close to each other in the circumferential direction at two circumferential positions (180 degree symmetrical positions). A coil spring 10 is interposed between the proximal end portion 91a and the distal end portion 91b. The coil spring 10 corresponds to a “spring” described in claim 3, and holds the outer peripheral surface of the friction material 92 in the arm 9 in close contact with the inner peripheral surface of the cylindrical portion 4 b of the pulley 4. As described above, the distal end portion 91b of the arm main body 91 and the proximal end portion 91a of the arm main body 91 opposed to the arm main body 91 are biased in a direction in which they are separated from each other.

  Also, the coil spring 10 has a holding hole formed in the base end portion 91a of the arm main body 91 and a tip end portion 91b of the other arm main body 91 opposite to the both ends so that the coil spring 10 does not fall off due to centrifugal force or the like. It is fitted in the holding hole formed in.

  An inner pressing member 11 is attached to the outer peripheral surface of the intermediate cylinder 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 the inner surface of the inward flange 4c is provided with PTFE (polytetrafluoroethylene) having excellent slidability and wear resistance. An inner thrust bearing 12 formed into a flat washer shape with a synthetic resin material such as fluoroethylene is slidably in close contact. A thrust spring 13 made of a rubber-like elastic material (rubber material or synthetic resin material having rubber-like elasticity) is integrally provided on a surface of the flange portion 11b of the inner pressing member 11 facing the inward flange 4c. The inner thrust bearing 12 is integrally provided on the end surface of the thrust spring 13, that is, the thrust spring 13 applies an appropriate close contact pressure to the inner surface of the inward flange 4c.

  An outer pressing member 14 is attached to the inner peripheral surface of the intermediate cylinder portion 1 c of the hub 1. The outer pressing member 14 is manufactured by press molding of a metal plate or the like, and is externally attached from the fitting cylinder portion 14a press-fitted to the inner peripheral surface of the intermediate cylinder portion 1c and the front end portion thereof. It has a flange portion 14b developed in the radial direction. The flange portion 14b is located on the front side of the inward flange 4c of the pulley 4, and the outer thrust bearing 15 is slidable between the inward flange 4c and the flange portion 14b facing each other in the axial direction. Intervened. The outer thrust bearing 15 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 that is relatively disposed between the flange portion 11b of the inner pressing member 11 and the flange portion 14b of the outer pressing member 14 through the thrust spring 13, the inner thrust bearing 12, and the outer thrust bearing 15. Axial displacement is regulated by being pinched so as to be 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 and the circumferential relative displacement of the hub 1 and the pulley 4 due to rotational fluctuations are caused by the outer peripheral surface of the friction material 92 in the arm 9 and the inner peripheral surface of the cylindrical portion 4b of the pulley 4. The rotation of the pulley 4 is smoothed.

  More specifically, when a starting torque in the forward rotation direction (clockwise direction in FIG. 2) is applied from the crankshaft to the hub 1 by starting the internal combustion engine, this starting torque is transmitted to the link 7 via the mounting shaft 6. Further, it is transmitted to the arm 9 via the pin 8. Therefore, the friction material 92 of the arm 9 held in close contact with the cylindrical portion 4 b of the pulley 4 by the urging force of the coil spring 10 slides relative to the hub 1 while sliding on the cylindrical portion 4 b. At this time, the link 7 tends to swing toward the outer diameter side about the mounting shaft 6 due to the frictional resistance of the friction material 92 against the cylindrical portion 4b. The arm 9 connected to the end through a pin 8 so as to be swingable is given a behavior toward the outer diameter side. For this reason, the frictional force of the friction material 92 against the cylindrical portion 4b increases, whereby torque in the forward rotation direction is transmitted from the arm 9 to the pulley 4, that is, the friction material 92 and the cylinder of the pulley 4 in the boom 9 are transmitted. The pulley 4 starts to rotate while the sliding of the portion 4b gradually decreases.

  In the input of the periodic rotation fluctuation of the crankshaft, 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 on the pulley 4 side including the belt and the auxiliary machine. However, in the retard angle differential of the pulley 4, as described above, the frictional force of the friction material 92 of the arm 9 against the cylindrical portion 4 b of the pulley 4 increases and slipping decreases, and in the advance angle differential of the pulley 4. The operation opposite to the above is repeated such that the frictional force of the friction material 92 decreases and the slip increases. For this reason, the repetitive circumferential relative displacement between the hub 1 and the pulley 4 due to relatively small rotational fluctuations is absorbed by the sliding of the friction material 92 of the arm 9 and the cylindrical portion 4b of the pulley 4, thereby causing the belt and the auxiliary machine to move. The smooth rotation on the side of the pulley 4 is maintained.

  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 internal combustion engine is stopped, the forward rotation of the hub 1 is decelerated, so that the pulley 4 is greatly advanced with respect to the hub 1 by the inertia on the pulley 4 side including the belt and the auxiliary machine. In this case, as described above, since the frictional engagement between the friction material 92 of the arm 9 and the cylindrical portion 4b of the pulley 4 is not performed, the torque transmission is interrupted and the overrun of the pulley 4 with respect to the hub 1 is allowed. The

  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.

Reference Signs List 1 hub 2 annular mass 3 mass support elastic body 4 pulley 7 link 9 arm 91 arm body 92 friction material 10 coil spring (spring)
TVD torsional damper section

Claims (4)

  A hub that is attached to a rotating shaft and rotates integrally with the rotating shaft, a pulley that is concentrically disposed on the outer periphery of the hub and that can rotate relative to the hub, and swings at a predetermined circumferential position of the hub. A link that is slidably coupled and has a swing end that faces the forward rotation side of the hub, and a link that is swingably coupled to the swing end of the link and extends in an arc shape toward the forward rotation side of the hub. A rotation fluctuation absorbing damper pulley comprising an arm whose outer peripheral surface is slidably in close contact with the inner peripheral surface of the pulley.   2. The rotation fluctuation absorbing damper pulley according to claim 1, wherein a friction material having an appropriate friction coefficient is provided on an outer peripheral portion of the arm, and the arm is in close contact with the inner peripheral surface of the pulley in the friction material.   The rotation fluctuation absorbing damper pulley according to claim 1 or 2, further comprising a spring for holding the arm in contact with the inner peripheral surface of the pulley.   The torsional damper part which consists of a cyclic | annular mass arrange | positioned concentrically with a hub and the mass support elastic body which elastically supports this cyclic | annular mass to a hub is provided. Rotational fluctuation absorbing damper pulley.

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