JP5800132B2 - Torque fluctuation absorbing damper - Google Patents

Description

  The present invention relates to a torque fluctuation absorbing damper in which a pulley that transmits torque from an output shaft of a rotary drive device such as an internal combustion engine to another rotating device is provided with a mechanism that absorbs fluctuations in transmission torque.

  A part of the driving force generated in the internal combustion engine of an automobile is given to an auxiliary device such as an alternator or a water pump from a pulley provided at the tip of the crankshaft via a belt wound around the pulley. Since the shaft rotates with torque fluctuation, the pulley is provided with a torque fluctuation absorbing mechanism for absorbing torque fluctuation and smoothing transmission torque. FIG. 6 shows a typical prior art of such a torque fluctuation absorbing damper.

  That is, this type of torque fluctuation absorbing damper includes a hub 100 that is attached to the shaft end of a crankshaft of an internal combustion engine for an automobile and rotates integrally, and a dynamic damper portion 110 and a flexible coupling portion 120 that are attached to the hub 100. Is provided.

  The dynamic damper portion 110 has a structure in which a first elastic body 111 is press-fitted between an outer cylinder portion 101 of the hub 100 and an annular mass body 112 disposed on the outer periphery thereof. Further, the coupling portion 120 extends from the pulley 121 supported on the outer periphery of the annular mass body 112 via a radial bearing 123, and the back surface side (right side in FIG. 6) of the hub 100 toward the inner diameter direction. The thrust bearing 122 interposed between the existing inward flange portion 121a and the outer cylinder portion 101 of the hub 100, and the inner diameter side of the outer cylinder portion 101 of the hub 100 from the inner diameter of the inward flange portion 121a of the pulley 121. A radial bearing 123 interposed between the extending sleeve portions 121b, a sleeve 103 fitted to the outer peripheral surface of the inner cylinder portion 102 of the hub 100, and a sleeve portion 121b of the pulley 121 are vulcanized and bonded. A second elastic body 124.

  In other words, this type of torque fluctuation absorbing damper absorbs torque fluctuation from the crankshaft to the hub 100 while absorbing torque fluctuations in the flexible coupling portion 120 by the torsional direction shear deformation action of the second elastic body 124. 121, and a dynamic damper portion 110 composed of a spring-mass system composed of the first elastic body 111 and the annular mass body 112 resonates in the torsional direction in the resonance frequency range of the crankshaft, whereby the crankshaft It exhibits a vibration damping function that dynamically absorbs resonance (see Patent Document 1).

Utility model registration No. 2606562

  However, the conventional torque fluctuation absorbing damper has a problem of causing slippage between the pulley 121 and a belt (not shown) wound around the pulley 121 when the internal combustion engine is rapidly decelerated or stopped. When such a belt slip occurs, not only an abnormal noise called “belt squeal” is generated, but also there is a concern that the belt is worn and the durability of the belt is deteriorated, thereby hindering running.

  The present invention has been made in view of the above points, and a technical problem thereof is torque that can transmit torque while absorbing fluctuations and that can prevent occurrence of belt slip. It is to provide a variable absorption damper.

As means for effectively solving the above technical problem, a torque fluctuation absorbing damper according to the invention of claim 1 includes a hub, a pulley supported to be relatively rotatable on the hub, and an inner periphery of the pulley. A spring clutch arranged, a coupling rubber having one end attached to the hub and the other end connected to one end of the spring clutch, and a slidably interposed between the spring clutch and the inner peripheral surface of the pulley. The spring clutch is wound so that the diameter of the spring clutch is increased in the differential angle of the pulley with respect to the forward rotation of the hub and the diameter of the spring clutch is reduced in the advance angle differential. It is

  According to the above configuration, when a differential angle with the hub is generated in the pulley due to the torque in the forward rotation direction, the spring clutch receives a torsional deformation so as to expand the diameter and presses the friction member against the inner peripheral surface of the pulley. Therefore, the frictional force between the spring clutch, the friction member, and the pulley increases, and torque in the forward rotation direction is transmitted to the pulley. Also, when the forward rotation is decelerated, if the pulley causes an advance angle differential with the hub due to the inertia on the pulley side, the spring clutch undergoes a torsional deformation to reduce the diameter, so the spring clutch, friction member and pulley This reduces the frictional force of the pulley, which causes the pulley to rotate freely and prevents slippage of the pulley and the belt wound around the outer periphery thereof.

According to a second aspect of the present invention, there is provided the torque fluctuation absorbing damper according to the first aspect , wherein a pair of thrust bearings are arranged on both sides in the axial direction of the pulley, and a coupling rubber is provided with the pair of thrust bearings and the pulley as a hub. It also serves as a means for pressing toward the flange side.

  According to the above configuration, the coupling rubber presses the pulley and the pair of thrust bearings disposed on both sides in the axial direction thereof toward the flange side of the hub, whereby the pulley is interposed between the coupling rubber and the flange via the thrust bearing. Therefore, the pulley is stably supported in the axial direction.

According to a third aspect of the present invention, there is provided the torque fluctuation absorbing damper according to the first or second aspect , wherein the pulley is provided with a dust cover surrounding the outside of the spring clutch, and the coupling rubber is provided with the dust cover and the sliding cover. A seal lip that is movably brought into close contact is formed.

  According to the above configuration, the dust cover provided on the pulley and the seal lip slidably brought into contact with the dust cover prevent dust and the like from entering the sliding portion of the spring clutch.

  According to the torque fluctuation absorbing damper according to the present invention, the torque transmission in the forward direction is performed between the hub and the pulley via the coupling rubber and the spring clutch, and the torque transmission in the reverse direction is interrupted during deceleration. And slipping of the belt wound around the outer periphery thereof can be effectively prevented. In addition, since the coupling rubber undergoes torsional deformation, fluctuations in the transmission torque are absorbed, and damage to the spring clutch is prevented.

  In addition, by slidably inserting a friction member between the spring clutch and the pulley, the durability of the spring clutch is increased, and the coupling rubber can also serve as a support means for supporting the pulley via a thrust bearing. In addition, by providing a seal lip that prevents dust and the like from entering the sliding portion of the spring clutch, the initial function can be maintained over a long period of time.

1 is a cross-sectional view showing a preferred embodiment of a torque fluctuation absorbing damper according to the present invention by cutting along a plane passing through an axis O. FIG. It is a cross-sectional perspective view which shows a part of coupling rubber in embodiment shown in FIG. It is a perspective view which shows the 2nd thrust bearing in embodiment shown in FIG. It is a perspective view which shows the friction member in embodiment shown in FIG. It is a perspective view which shows the spring clutch in embodiment shown in FIG. It is sectional drawing which cuts and shows an example of the torque fluctuation absorption damper by a prior art by the plane which passes along the axis O.

  Hereinafter, a preferred embodiment of a torque fluctuation absorbing damper according to the present invention will be described with reference to the drawings. The “front side” used in the following description refers to the left side in each figure, that is, the front side of the vehicle, and the “rear side” refers to the right side in each figure, that is, an internal combustion engine (not shown). It is the side to do.

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, and includes an inner cylinder portion 11 fixed to the crankshaft, an intermediate portion 12 extending from the front end portion to the outer diameter side, It has an outer cylinder portion 13 extending from the outer diameter end portion to the back side, and an outer diameter flange 14 extending from the front end portion in the outer diameter direction. Reference numeral 11a denotes a key groove formed in the inner peripheral shaft hole of the inner cylinder portion 11, and the outer diameter flange 14 corresponds to the "flange provided on the hub" described in claim 2. It is.

  A pulley 2 is concentrically disposed close to the outer peripheral side of the hub 1. The pulley 2 includes a pulley main body 21 manufactured by casting a metal material or the like, and a dust cover 22 manufactured by press molding of a metal plate or the like and integrally fitted to the pulley main body 21.

  The pulley main body 21 in the pulley 2 extends from the inner periphery to the inner diameter direction of the winding cylinder portion 21a having a poly V groove formed on the outer peripheral surface thereof, and faces the outer diameter flange 14 of the hub 1 in the axial direction from the back side. A supported flange portion 21b and a supported cylinder portion 21c that extends from the inner diameter end portion of the supported flange portion 21b toward the back side and faces the outer peripheral surface of the outer cylinder portion 13 of the hub 1 in the radial direction. . A belt (not shown) is wound around the outer peripheral surface of the winding cylinder portion 21a in which the poly V groove is formed.

  The radial bearing 3 is slidably interposed between the outer cylindrical portion 13 of the hub 1 and the supported cylindrical portion 21c of the pulley main body 21 that is opposed to the outer cylindrical portion 21 in the radial direction. The radial bearing 3 is made of a synthetic resin material such as PTFE (polytetrafluoroethylene) having excellent slidability and wear resistance, and is formed into a cylindrical shape, that is, the pulley body 21 (pulley 2). Is supported in the radial direction via the radial bearing 3 in a state in which the outer cylindrical portion 13 of the hub 1 can be relatively rotated.

  The first thrust bearing 4 is slidably interposed between the outer diameter flange 14 of the hub 1 and the supported flange portion 21b of the pulley body 21 facing the axial direction from the back side. Yes. The first thrust bearing 4 is made of a synthetic resin material such as PTFE having excellent slidability and wear resistance, and is formed into a flat washer shape.

  A coupling rubber 5 is disposed on the opposite side of the hub 1 from the outer diameter flange 14 in the axial direction as viewed from the supported flange portion 21b of the pulley body 21, that is, on the back side of the supported flange portion 21b. As shown in the perspective view of FIG. 2, the coupling rubber 5 includes a fitting cylinder portion 51 a press-fitted and fitted to the inner peripheral surface of the outer cylinder portion 13 of the hub 1, and a hub from the rear side end portion. A metal holder 51 formed of a disk portion 51b that expands in a radial direction toward the space on the back side of the outer diameter flange 14 of the first outer diameter flange 14, and a front side of the disk portion 51b of the holder 51, and the pulley body 21 covered It comprises a flat washer-like retainer 52 facing the support flange portion 21 b in the axial direction, and a coupling rubber main body 53 provided integrally between the retainer 52 and the disc portion 51 b of the holder 51. A seal lip 53 a is formed on the outer peripheral surface of the coupling rubber main body 53. The holder 51 corresponds to one end of the coupling rubber described in claim 1, and the retainer 52 corresponds to the other end of the coupling rubber described in claim 1.

  The coupling rubber main body 53 is made of a rubber-like elastic material (rubber material or synthetic resin material having rubber-like elasticity) excellent in heat resistance, cold resistance and mechanical strength, that is, the coupling rubber 5 is A holder 51 and a retainer 52 are concentrically set in a mold (not shown), and an unvulcanized rubber material is placed in an annular cavity defined by clamping the mold between the holder 51 and the retainer 52. The coupling rubber body 53 is integrally vulcanized and molded (vulcanized and bonded) to the holder 51 and the retainer 52 by filling, heating and pressurizing.

  The second thrust bearing 6 is slidably interposed between the retainer 52 of the coupling rubber 5 and the supported flange portion 21b of the pulley body 21 facing the retainer 52. The second thrust bearing 6 is made of a synthetic resin material such as PTFE having excellent slidability and wear resistance, and is formed into a flat washer shape. The retainer 52 is formed with a plurality of engagement protrusions 52a that are driven out toward the front side at a predetermined interval. The second thrust bearing 6 has a plurality of engagement holes 6a as shown in FIG. Is opened at a position corresponding to the engaging protrusion 52a, and the relative rotation of the retainer 52 and the second thrust bearing 6 is restricted by fitting the two 52a and 6a together as shown in FIG. ing.

  The coupling rubber body 53 of the coupling rubber 5 is pre-compressed to give an axial biasing force as a reaction force, and the retainer 52 is applied to the second thrust bearing 6 by this axial biasing force. It is in pressure contact. For this reason, the second thrust bearing 6, the supported flange portion 21 b of the pulley body 21, and the first thrust bearing 4 are pressed toward the outer diameter flange 14 of the hub 1, whereby the first thrust bearing 4 The second thrust bearing 6 is given a predetermined axial restraining force on the supported flange portion 21b of the pulley body 21.

  The dust cover 22 in the pulley 2 includes a sleeve portion 22a that is press-fitted and fitted to the inner peripheral surface of the winding cylinder portion 21a of the pulley body 21, a back portion 22b that extends from the end on the back side to the inner diameter side, and It consists of an inner diameter cylindrical portion 22c folded from the inner diameter end portion to the front side.

  The friction member 7 is disposed inside the dust cover 22 of the pulley 2 so as to be slidable with the inner peripheral surface of the dust cover 22. That is, the friction member 7 has a cylindrical shape as a whole, and the end portion on the back side is bent toward the inner diameter side, and the cross-sectional shape cut by a plane passing through the axis O forms a substantially L-shape. And a friction member body 71 made of a synthetic resin material such as PTFE having excellent wear resistance, and a metal sleeve 72 integrally joined to the inner periphery thereof, as shown in FIG. By being cut 7a, the diameter can be increased or reduced.

  The outer peripheral surface of the friction member main body 71 and the end surface on the back surface side of the friction member 7 are slidably in contact with the inner peripheral surface of the sleeve portion 22a of the dust cover 22 and the inner surface of the back surface portion 22b of the pulley 2.

  A spring clutch 8 is disposed inside the dust cover 22 of the pulley 2 and on the inner peripheral side of the friction member 7. The spring clutch 8 has a cylindrical coil shape as shown in FIG. 5, and an engagement protrusion 8 a formed at the end on the front side is attached to the retainer 52 of the coupling rubber 5 as shown in FIG. 2. The retainer 52 is connected in the circumferential direction by being inserted into and engaged with the established engagement hole 52b. That is, the front end of the spring clutch 8 is connected to the hub 1 via the coupling rubber 5, and the outer periphery thereof is elastically and slidable on the inner peripheral surface of the metal sleeve 72 in the friction member 7. Is touching.

  The spring clutch 8 is in contact with the torque transmitted from the hub 1 through the coupling rubber 5 to the engagement protrusion 8a at one end thereof and the inner peripheral surface of the metal sleeve 72 in the friction member 7. Torque deformation is received by the frictional force, torque in the direction of increasing the diameter (torque in the R1 direction shown in FIG. 5) is transmitted by the torsional deformation, and torque in the direction of reducing the diameter (torque in the R2 direction shown in FIG. 5) is cut off. To do. Therefore, the winding direction of the spring clutch 8 is determined when a delay angle differential of the pulley 2 with respect to the rotation of the hub 1 in the positive direction (R1 direction shown in FIG. 5) given to the engagement protrusion 8a occurs (the rotation of the hub 1). When the speed is larger than that of the pulley 2) and the advance angle differential of the pulley 2 with respect to the forward rotation of the hub 1 occurs (when the rotational speed of the hub 1 is slower than the pulley 2). The spiral direction is reduced.

  The seal lip 53a formed on the outer peripheral surface of the coupling rubber main body 53 in the coupling rubber 5 is slidably in close contact with the inner peripheral surface of the inner diameter cylindrical portion 22c of the dust cover 22 in the pulley 2. The space in which the friction member 7 and the spring clutch 8 are disposed is sealed by a seal lip 53a that is in close contact with the dust cover 22 and the inner diameter cylindrical portion 22c.

  The torque fluctuation absorbing damper having the above configuration is rotated together with the crankshaft when the inner cylinder portion 11 of the hub 1 is mounted on the shaft end of the crankshaft (not shown). At this time, the drive torque in the forward rotation direction of the crankshaft is transmitted from the hub 1 through the coupling rubber 5 to the engagement protrusion 8a of the spring clutch 8 from the engagement hole 52b provided in the retainer 52. Therefore, when the hub 1 precedes the pulley 2 in the forward rotation direction and the pulley 2 produces a retarded differential with the hub 1, the spring clutch 8 contacts the inner peripheral surface of the metal sleeve 72 in the friction member 7. Torsional deformation in the direction of expanding the diameter by the frictional force. For this reason, the friction member 7 cut at one place in the circumferential direction is pressed by the spring clutch 8 that expands in diameter, so that the outer peripheral surface of the friction member main body 71 becomes the inner peripheral surface of the sleeve portion 22a of the dust cover 22 in the pulley 2. As a result of the pressure contact, the frictional force between the spring clutch 8, the friction member 7, and the sleeve portion 22 a increases, and torque transmission in the forward rotation direction from the hub 1 via the spring clutch 8 and the friction member 7 is performed.

  Note that a part of the input torque to the hub 1 includes the frictional force of the radial bearing 3 interposed between the outer cylinder portion 13 of the hub 1 and the supported cylinder portion 21c of the pulley body 21, and the outer diameter flange of the hub 1. 14 and the frictional force of the first thrust bearing 4 interposed between the supported flange portion 21 b of the pulley body 21 and the second interposed between the supported flange portion 21 b and the retainer 52 of the coupling rubber 5. It is also transmitted to the pulley 2 by the frictional force of the thrust bearing 6.

  The driving torque transmitted to the pulley 2 is transmitted to the rotating shaft of an auxiliary machine such as a cooling water circulation pump, an alternator, a cooling fan, etc. via a belt wound around the winding cylinder portion 21a of the pulley body 21. Is done.

  Here, in the internal combustion engine, since the reciprocating motion of the piston in the cylinder is converted into the rotational motion of the crankshaft, torque variation occurs in the crankshaft as it rotates, and therefore a hub attached to the end of the shaft The vibration in the torsional direction is input to 1 to cause a swing, but such torque fluctuation is absorbed by the coupling rubber 5 between the hub 1 and the spring clutch 8. Specifically, the coupling rubber body 53 is subjected to shear deformation in the torsional direction between the holder 51 fitted to the hub 1 and the retainer 52 coupled to the spring clutch 8, so that the kinetic energy due to torque fluctuation is reduced. Since the heat is consumed as thermal energy by the internal friction of the coupling rubber main body 53, sudden torque fluctuations acting on the engaging protrusion 8a of the spring clutch 8 are alleviated, and the spring clutch 8 is prevented from being damaged.

  Note that a part of the fluctuation of the transmission torque from the hub 1 is also absorbed by the sliding of the radial bearing 3, the first thrust bearing 4, and the second thrust bearing 6.

  Further, when the rotation in the forward direction is decelerated, the belt wound around the winding cylinder portion 21a of the pulley main body 21 in the pulley 2 and the auxiliary machine driven by the belt try to continue the constant speed rotation by inertia. When the pulley 2 undergoes a differential advance with respect to the hub 1, the spring clutch 8 is subjected to torsional deformation in the direction of reducing its diameter by the frictional force with the inner peripheral surface of the metal sleeve 72 of the friction member 7, and thus the spring clutch 8 The frictional force between the friction member 7 and the pulley 2 (the sleeve portion 22a of the dust cover 22) is reduced, whereby the pulley 2 is in a free rotating state, and the pulley body 21 and the belt wound around the outer periphery thereof are slipped. Is prevented. Therefore, it is possible to prevent the occurrence of belt slip and the occurrence of “belt squealing” and the deterioration of the durability of the belt in all regions from the rotational speed 0 to the normal rotational region.

  In addition, a seal lip 53a formed on the coupling rubber body 53 of the coupling rubber 5 is slidably in close contact with the inner peripheral surface of the inner diameter cylindrical portion 22c of the dust cover 22 in the pulley 2, so that the friction member 7 and the space S in which the spring clutch 8 is disposed are sealed, so that dust or the like on the sliding portions of the friction member 7 and the spring clutch 8 and eventually the sliding portions of the radial bearing 3 and the second thrust bearing 6 can be obtained. Intrusion is prevented and the initial function can be maintained for a long time.

  And according to the said structure, while the coupling rubber 5 is a means which relieve | moderates the fluctuation | variation of transmission torque as mentioned above, and prevents the failure | damage of the spring clutch 8, it is the 1st thrust bearing 4 and the 2nd thrust bearing. 6 also serves as a means for applying an axial restraining force to the supported flange portion 21b of the pulley body 21 by 6 and a means for preventing dust and the like from entering the sliding portions of the friction member 7 and the spring clutch 8. .

  In the above-described embodiment, the friction member 7 has a C shape obtained by cutting at one place in the circumferential direction. However, a collet shape having slits at a plurality of places, or a segment shape separated into a plurality in the circumferential direction, and It is also possible to apply.

  In the embodiment described above, the outer peripheral surface of the friction member 7 (friction member main body 71) is in intimate contact with the inner peripheral surface of the sleeve portion 22a of the dust cover 22 in the pulley 2. It can also be set as the structure closely_contact | adhered to the inner peripheral surface of the part 21a so that sliding is possible.

  Further, the friction member 7 is not interposed between the spring clutch 8 and the pulley main body 21, and the outer peripheral surface of the spring clutch 8 is the inner peripheral surface of the sleeve portion 22 a of the dust cover 22 or the winding cylinder portion 21 a of the pulley main body 21. In this case, it is desirable to enclose lubricating oils and fats in the space S inside the dust cover 22.

1 Hub 14 Outer Diameter Flange 2 Pulley 21 Pulley Body 22 Dust Cover 3 Radial Bearing 4 First Thrust Bearing (Thrust Bearing)
5 Coupling rubber 51 Holder 52 Retainer 53 Coupling rubber body 53a Seal lip 6 Second thrust bearing (thrust bearing)
7 Friction member 71 Friction member body 72 Sleeve 8 Spring clutch

Claims (3)

A hub, a pulley supported rotatably on the hub, a spring clutch disposed on an inner periphery of the pulley, a cup having one end attached to the hub and the other end connected to one end of the spring clutch A ring rubber, and a friction member capable of expanding and reducing the diameter, which is slidably interposed between the spring clutch and the inner peripheral surface of the pulley , wherein the spring clutch is against the forward rotation of the hub. A torque fluctuation absorbing damper, wherein the torque fluctuation absorbing damper is wound so that the diameter is increased in the retard angle differential of the pulley and is reduced in the advance angle differential. The pair of thrust bearings are disposed on both sides of the pulley in the axial direction, and the coupling rubber also serves as means for pressing the pair of thrust bearings and the pulley toward the flange provided on the hub . Torque fluctuation absorbing damper. The dust cover that surrounds the outside of the spring clutch is provided on the pulley, and a sealing lip that is slidably in contact with the dust cover is formed on the coupling rubber. Torque fluctuation absorbing damper.

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