JP4662044B2 - Torque fluctuation absorbing damper - Google Patents

Description

  The present invention relates to a torque fluctuation absorbing damper that transmits torque from a drive shaft of a rotating device such as an internal combustion engine in an automobile, an agricultural machine, a construction machine, a small ship, etc. to another rotating device and absorbs the fluctuation of the torque.

  A part of the driving force of the automobile engine is given from an pulley provided at the tip of the crankshaft to an auxiliary device such as an alternator or a water pump via an endless belt. Therefore, the pulley is provided with a torque fluctuation absorbing damper for absorbing torque fluctuation and smoothing transmission torque.

FIG. 2 is a half sectional view showing an example of a torque fluctuation absorbing damper according to the prior art cut along a plane passing through an axis O. The left side in FIG. 2 is the front side of the vehicle, and the right side is the vehicle. This is the back side where the internal combustion engine exists. This type of torque fluctuation absorbing damper includes a hub 100 that is attached to a shaft end of a crankshaft of an automobile engine and rotates integrally, and a dynamic damper portion 110 and a flexible coupling portion 120 that are attached to the hub 100.

  The hub 100 is made of a metal material, and is formed concentrically with each other on the boss portion 101 fixed to the crankshaft, the disc portion 102 extending to the outer periphery thereof, and the front side of the disc portion 102. It consists of an inner peripheral cylinder part 103 and a rim part 104. The dynamic damper portion 110 has a structure in which an annular mass body 112 is attached to the outer periphery of the rim portion 104 of the hub 100 via a first elastic body 111. The coupling portion 120 extends from the inner peripheral side of the rim portion 104 so as to surround the front side and the outer peripheral side of the dynamic damper portion 110, and has a cross section (shown in the drawing) cut along a plane passing through the axis. A pulley 121 having a substantially U-shape, a synthetic resin bearing 122 interposed between the rim portion 104 and the supported cylinder portion 121a of the pulley 121 located on the inner periphery thereof, and the front side of the disc portion 102 of the hub 100 The second elastic body 123 connects the inner peripheral cylinder portion 103 of the hub 100 and the supported cylinder portion 121a of the pulley 121.

  That is, this torque fluctuation absorbing damper applies torque input from the crankshaft to the hub 100 to the pulley 121 while absorbing the torque fluctuation by the torsional direction shear deformation action of the second elastic body 123 in the flexible coupling portion 120. The dynamic damper unit 110 configured to transmit and resonate in the torsional direction in the resonance frequency region of the crankshaft exhibits a damping function that absorbs the resonance of the crankshaft. (For a similar torque fluctuation absorbing damper, see, for example, Patent Document 1).

  Here, the torque fluctuation of the crankshaft is prominently generated mainly in a low rotation region such as idling. Therefore, the spring element of the coupling is required to be soft and greatly deformed. Therefore, the second elastic body 123 needs to be increased in size in the radial direction in order to achieve a low spring constant and improved durability. As a result, the hub 100 is increased in diameter, and as a result, the annular mass body 112 and the pulley 121 are increased in size. The diameter was coming. Moreover, since it is a structure that receives a radial load derived from the tension of a drive belt (not shown) wound around the outer peripheral surface of the pulley 121 at the supported cylindrical portion 121a away from the load input surface to the inner peripheral side, There is a problem that it is necessary to secure a large rigidity in the pulley 121, and the manufacturing cost of the pulley 121 becomes high.

  Further, although the damping force in the rotational direction due to the physical properties of the second elastic body 123 is supplemented by the damping force due to the sliding of the bearing 122, the bearing 122 is disposed on the inner peripheral side of the rim portion 104 of the hub 100. Since the diameter is relatively small, the load supporting area is small, and therefore, wear tends to progress early. Therefore, there is a problem in that the damping force in the bearing 122 varies greatly with time and the radial position of the pulley 121 becomes unstable due to wear of the bearing 122.

  In addition, in order to prevent excessive deformation of the second elastic body 123 when a large torque is input, a pin 113 driven into the annular mass body 112 and a rotation direction stopper by an engagement hole 121b provided in the pulley 121 are provided. However, in such a configuration, dust or the like easily enters the sliding portion of the bearing 122 from the front side (left side in the figure) through the engagement hole 121b. This also causes the early wear of the bearing 122. It was.

FIG. 3 is a half cross-sectional view showing a torque fluctuation absorbing damper according to another conventional technique, cut along a plane passing through the axis O thereof. In the torque fluctuation absorbing damper of FIG. 3 , the pulley 121 is supported on the outer periphery of the annular mass 112 in the dynamic damper portion 110 via the radial bearing 126, and the flexible coupling portion 120 is a flange extending from the pulley 121 to the inner peripheral side. The thrust receiver 125 is press-fitted into the inner peripheral cylinder part 103 by connecting the axially opposed surfaces of the part 121 c and the metal ring 124 press-fitted into the inner peripheral cylinder part 103 of the hub 100 via the second elastic body 123. 2 and the flange 121c of the pulley 121 is different from the previous FIG. 2 in that a thrust bearing 127 is interposed.

According to this configuration, since the thrust bearing 127 is always pressed in the axial direction by the reaction force due to the axial pre-compression of the second elastic body 123, the pulley 121 does not rattle even if the thrust bearing 127 is worn. Less and stable damping force can be obtained. Further, since the radial bearing 126 supports the inner peripheral portion of the pulley 121, it can efficiently receive a radial load derived from the tension of a drive belt (not shown) wound around the outer peripheral surface of the pulley 121. can, Therefore, compared to that of FIG. 2 it is possible to reduce the rigidity of the pulley 121. (For example, refer to Patent Document 2).

However, according to the torque fluctuation absorbing damper of FIG. 3 , in addition to the step of press-fitting the metal ring 124 vulcanized and bonded to the second elastic body 123 into the inner peripheral cylindrical portion 103 of the hub 100, the metal ring 124 (or the inner ring The process of press-fitting the thrust receiver 125 into the peripheral cylinder portion 103) is necessary, and the manufacturing cost is high.

Further, since the thrust receiver 125 for supporting the thrust bearing 127 from the front and pre-compressing the second elastic body 123 is necessary, it is difficult to reduce the product price due to the large number of parts. In addition, foreign matter easily enters the sliding portion of the thrust bearing 127 from the front side, and the thrust bearing 127 is quickly worn.

Utility model registration No. 2606562 Japanese Patent No. 3155280

  The present invention has been made in view of the above points, and the technical problem is that the number of parts is reduced, the assembly is easy, the durability is excellent, and the stable attenuation is achieved. An object of the present invention is to provide a torque fluctuation absorbing damper.

As a means for effectively solving the technical problem described above, the torque fluctuation absorbing damper according to the invention of claim 1 is configured such that the annular mass body is in the circumferential direction via the first elastic body made of a rubber-like elastic material on the hub. The pulley is connected to the hub or the annular mass body via a radial bearing, and the stay is press-fitted into a support cylinder portion formed on the hub and located on the inner peripheral side of the first elastic body. The inner peripheral flange portion formed on the inner peripheral portion of the pulley and the stay located on the axially outer side thereof are connected in the axial direction via a second elastic body made of a rubber-like elastic material. A thrust bearing is interposed between the axially opposed surfaces of the pulley and the hub or the annular mass body, which is narrowed by the axial compression force of the second elastic body, and a thrust stopper is press-fitted into the support cylinder portion. The The outer peripheral portion of Sutosutoppa is characterized in that the faces from the axially outside to the pulley.

  According to this configuration, the pulley is incorporated from one side in the axial direction of the hub and the annular mass body, and the stay coupled to the outer side in the axial direction of the inner peripheral flange portion of the pulley via the second elastic body is supported by the hub. The second elastic body is pre-compressed in the axial direction by being press-fitted into the cylindrical portion, and a hub or an annular mass body that is narrowed by the axial compression reaction force and a thrust bearing arranged in advance between the opposed surfaces of the pulley. The pulley is positioned with respect to the axial direction. That is, in order to receive the compressive force of the second elastic body pre-compressed by the incorporation of the stay with the thrust bearing via the pulley, in order to hold the thrust bearing separately from the stay and to apply pre-compression to the second elastic body There is no need to provide any parts.

  A torque fluctuation absorbing damper according to a second aspect of the present invention is the structure according to the first aspect, wherein the torque fluctuation absorbing damper is loosely fitted to an engagement recess or an engagement hole formed in the hub or the annular mass body with an appropriate clearance in the circumferential direction. Thus, engagement protrusions for limiting the circumferential relative displacement between the hub and the pulley to a predetermined range are formed on the pulley.

  According to a third aspect of the present invention, in the torque fluctuation absorbing damper according to the first aspect, the engagement recess or the engagement hole is formed in the inner peripheral flange portion of the pulley, and the engagement recess or the engagement hole has a circular shape. Engagement protrusions that are loosely fitted with an appropriate clearance in the circumferential direction and limit the relative displacement in the circumferential direction of the hub and pulley to a predetermined range are provided on the inner surface of the hub.

According to the torque fluctuation absorbing damper according to the first aspect of the invention, the assembly of the second elastic body is precompressed in the axial direction and the pulley is positioned with respect to the axial direction by incorporating the pulley and the stay, so that assembly is easy. In addition, since the number of components is small, the manufacturing cost can be reduced. Further, even if the second elastic body is damaged, the pulley can be prevented from falling off by the thrust stopper, so that safety can be improved.

According to the torque fluctuation absorbing damper of the invention of claim 2, the number of parts is smaller than that provided with the engaging protrusions in the stopper for limiting the circumferential relative displacement of the hub and the pulley to a predetermined range as separate parts. Therefore, the manufacturing cost can be reduced. In addition, since the engagement state between the engagement recess or the engagement hole and the engagement protrusion constituting the stopper is maintained by the thrust stopper, the drive torque can be continuously transmitted.

  According to the torque fluctuation absorbing damper of the third aspect of the present invention, the engagement concave portion or the engagement hole constituting the stopper that limits the circumferential relative displacement of the hub and the pulley to a predetermined range is formed in the inner peripheral flange portion of the pulley. Because it is formed, it does not become an intrusion path for dust from the outside.

Hereinafter, a torque fluctuation absorbing damper according to the present invention will be described with reference to the drawings. FIG. 1 is a half sectional view showing an embodiment of a torque fluctuation absorbing damper according to the present invention by cutting along a plane passing through an axis O thereof. The “front side” used in the following description refers to the left side in FIG. 1 , that is, the front side of the vehicle, and the “rear side” refers to the right side in FIG. It is the side to do.

  In the form of FIG. 1, reference numeral 1 is a hub attached to a shaft end of a crankshaft (not shown) of an automobile engine. The hub 1 is manufactured by casting a metal material or the like, and includes a boss portion 11 fixed to the crankshaft, a disc portion 12 that extends from the front end portion to the outer peripheral side, and the disc portion. The support cylinder part 13 extended from the inner peripheral part of 12 to the front side, and the rim part 14 extended from the outer peripheral part of the disk part 12 to the front side.

  An annular mass body 2 is disposed on the outer periphery of the rim portion 14 of the hub 1, and the annular mass body 2 and the rim portion 14 are elastically movable in the circumferential direction via the first elastic body 3. The torsional damper portion TD is configured by being connected to the. The annular mass body 2 is manufactured by casting a metal material having a large specific gravity such as iron, and the first elastic body 3 is a rubber-like elastic material excellent in heat resistance, cold resistance and mechanical strength. It is vulcanized and press-fitted between the rim portion 14 of the hub 1 and the opposed peripheral surface of the annular mass 2.

  The torsional direction resonance frequency of the torsional damper part TD is a predetermined frequency at which the torsional angle of the crankshaft is maximized by the circumferential inertial mass of the annular mass body 2 and the torsional direction shear spring constant of the first elastic body 3. Is tuned to match the resonance frequency of the torsional direction of the crankshaft.

  Reference numeral 4 is a pulley. This pulley 4 is manufactured by press forming of a metal plate, and is provided with a pulley main body 41 disposed on the outer peripheral side of the annular mass body 2 and the annular mass body 2 and the first from the front end thereof. A front disk portion 42 extending inwardly on the front side of the elastic body 3 (torsional damper portion TD) and the front side of the rim portion 14 of the hub 1, and an inner peripheral end thereof, along the inner periphery of the rim portion 14. And a supported cylinder portion 43 extending toward the back surface, and an inner peripheral flange portion 44 extending from the end on the back side of the supported cylinder portion 43 toward the inner periphery along the front surface of the disk portion 12 of the hub 1. . A poly V groove 41a is formed on the outer peripheral surface of the pulley body 41, and an endless belt (not shown) is wound around the pulley main body 41.

A radial bearing 51 formed into a cylindrical shape with a synthetic resin material having a low friction coefficient and having excellent wear resistance such as PTFE is provided with an inner peripheral surface of a pulley body 41 of the pulley 4 and an annular mass body 2 on the inner peripheral side thereof. A thrust bearing 52 formed in a flat washer shape with a synthetic resin material having a low friction coefficient excellent in wear resistance such as PTFE is slidably interposed between the outer peripheral surface of the pulley 4 and the inner peripheral flange portion of the pulley 4. 44 is slidably interposed between the rear surface of 44 and the front surface of the disk portion 12 of the hub 1. Accordingly, the pulley 4 (supported cylinder portion 43) is concentrically supported by the rim portion 14 of the hub 1 via the radial bearing 51 so as to be capable of relative displacement in the circumferential direction.

  A stay 6 is press-fitted to the outer peripheral surface of the support cylinder portion 13 of the hub 1. The stay 6 is manufactured by stamping press molding of a metal plate or the like, and includes a sleeve 61 press-fitted into the outer peripheral surface of the support cylinder portion 13 with a required tightening margin, and an outer periphery from its front end. It consists of a flange main body 62 developed in a bowl shape to the side.

  The flange body 62 of the stay 6 and the inner peripheral flange portion 44 of the pulley 4 are opposed to each other in the axial direction in an annular space surrounded by the support cylinder portion 13, the disc portion 12 and the rim portion 14 in the hub 1. The flange main body 62 of the stay 6 is located on the axially outer side (front side) of the inner peripheral flange portion 44 of the pulley 4. The flange main body 62 and the inner peripheral flange portion 44 are connected in the axial direction via a second elastic body 7 made of a rubber-like elastic material having excellent heat resistance, cold resistance and mechanical strength.

  The second elastic body 7 has a stay 6 and a pulley 4 set concentrically in a mold (not shown), and a mold is formed between the flange main body 62 of the stay 6 and the inner peripheral flange portion 44 of the pulley 4. The annular cavity defined by the above is filled with an unvulcanized rubber material, heated and pressurized, and vulcanized and bonded to the flange main body 62 and the inner peripheral flange portion 44 simultaneously with the vulcanization molding. Appropriate axial precompression is provided between the flange body 62 and the inner peripheral flange portion 44. The second elastic body 7 transmits the driving torque input from the crankshaft to the hub 1 to the pulley 4 while being smoothed by a circumferential shear deformation action.

In this embodiment, the axial compression between the inner circumferential flange portion 44 of the pulley 4 with the thrust bearing 52 interposed therebetween and the disk portion 12 of the hub 1 is axially compressed by the second elastic body 7 according to claim 1. The thrust bearing 52 corresponds to the space between the axially opposed surfaces of the inner peripheral flange portion 44 and the disk portion 12 by the axial compression force of the second elastic body 7. It is sandwiched so as to be slidable at an appropriate surface pressure.

  The torque fluctuation absorbing damper having the above configuration is rotated together with the crankshaft by mounting the boss portion 11 of the hub 1 on the shaft end of the crankshaft of the engine (not shown). The driving torque of the crankshaft is transmitted from the hub 1 to the inner peripheral flange portion 44 of the pulley 4 via the stay 6 and the second elastic body 7, and further, a belt (not fixed) wound around the pulley body portion 41 of the pulley 4. Via a rotating fan of an auxiliary machine such as a cooling fan or an alternator.

  Periodic torque fluctuations that occur in the crankshaft as the engine is driven cause the second elastic body 7 to be sheared in the torsional direction between the flange main body 62 of the stay 6 and the inner peripheral flange portion 44 of the pulley 4. By this, since it is converted into thermal energy, the transmission torque to the belt is smoothed. Further, the torsional damper portion TD composed of the annular mass body 2 and the first elastic body 3 resonates in the circumferential direction in the frequency range where the torsional angle due to the torsional vibration of the crankshaft is maximum, and the torque due to the resonance is input. Since the vibration torque and the direction are reversed, the peak of the torsion angle due to the resonance of the crankshaft can be effectively reduced.

When the hub 1 and the pulley 4 are repeatedly displaced in the circumferential direction by the input of torque fluctuation, the thrust bearing 52 is connected to the inner peripheral flange portion 44 of the pulley 4 by the axial compression force of the second elastic body 7. between the disk portion 12 of the hub 1, it is slid in a suitable surface pressure, the radial bearing 51, the radial load from the belt tension, the inner peripheral surface of the pulley body 41 of the pulley 4 and the annular mass 2 In this case, an effective friction damping force can be obtained.

In the inner peripheral flange portion 44 of the pulley 4, a plurality of engagement holes 46 having a predetermined length centered on the shaft center O (the shaft center of the hub 1) O of the pulley 4 are opened at equal phase intervals. The engagement hole 46 has a recess 7a formed in the second elastic body 7. A part of the rubber material in the recess 7a covers the inner surface of the engagement hole 46 in a film shape. Yes.

  On the other hand, a plurality of engaging protrusions 17 protruding in the axial direction are integrally formed on the front surface of the disk portion 12 of the hub 1 at a phase interval corresponding to the engaging holes 46. The engagement protrusions 17 are loosely fitted to the engagement holes 46 (recesses 7a of the second elastic body 7) of the inner peripheral flange portion 44 of the pulley 4 with appropriate clearances on both sides in the circumferential direction. A stopper that effectively prevents excessive deformation and breakage of the second elastic body 7 due to resonance during cranking and input of excessive torque is configured by limiting the relative displacement in the circumferential direction of the hub 1 and the pulley 4 to a predetermined range. is doing.

  Further, a stepped portion 13a is formed on the outer peripheral surface of the support cylinder portion 13 in the hub 1 so as to abut the end portion of the sleeve 61 in the stay 6. The sleeve 61 has an axial length from the stepped portion 13a. The length in the axial direction up to the tip of the support cylinder 13 is longer. Therefore, the stay 6 protrudes from the front end of the support cylinder portion 13 to the front side in the illustrated attached state.

  Note that a notch 62a is formed in the flange main body 62 of the stay 6 on the same phase as the engagement hole 46 of the pulley 4 (the concave portion 7a of the second elastic body 7). Further, a recess 7b formed in the second elastic body 7 is opened in the notch 62a.

  In the above configuration, the notch 62a inserts the pulley body 41 of the pulley 4 into the outer periphery of the annular mass body 2 from the front side via the radial bearing 51 in the assembly of the torque fluctuation absorbing damper, and also the sleeve in the stay 6 When the 61 is press-fitted into the support cylinder portion 13 of the hub 1, the engagement hole 46 (the concave portion 7 a of the second elastic body 7) of the pulley 4 is positioned relative to the engagement protrusion 17 of the hub 1 with respect to the circumferential direction. It is a guide for matching.

Then, the end portion of the sleeve 61 in the stay 6 is brought into contact with the step portion 13 a formed on the outer peripheral surface of the support cylinder portion 13 in the hub 1 , whereby the axial positioning can be performed. Therefore, predetermined axial pre-compression to the second elastic body 7 can be easily provided.

  In addition, according to the above configuration, since the engaging protrusion 17 is formed integrally with the hub 1 disk portion 12, there is an advantage that the number of parts does not increase as in the case of using a pin, Since the engagement hole 46 does not open the gap where the thrust bearing 52 is interposed to the outside, it is possible to prevent dust and the like from intervening in the thrust bearing 52. Since the inner surface of the engagement hole 46 is covered with a part of a rubber material in a film shape, noise during interference with the engagement protrusion 17 can be effectively reduced.

Reference numeral 8 is a thrust stopper. Specifically, the thrust stopper 8 is manufactured by punching a metal plate or the like, and includes a sleeve 81 press-fitted to the inner peripheral surface of the support cylinder portion 13 in the hub 1 with a required tightening margin, It consists of a stopper main body 82 developed in a bowl shape from the front end to the outer peripheral side.

  The end portion of the sleeve 81 in the thrust stopper 8 is abutted with a step portion 13b formed on the inner peripheral surface of the support cylinder portion 13 in the hub 1, and the stopper main body 82 in the thrust stopper 8 The inner peripheral portion 82a contacts the flange main body 62 of the stay 6 from the front side, and the outer peripheral portion 82b of the inner side faces the front disc portion 42 of the pulley 4 in close proximity to the front disc side with a slight gap. Yes.

Therefore, the axial displacement restriction of the pulley 4 toward the front side is compensated by the stopper main body 82 of the thrust stopper 8. Further, the displacement of the pulley 4 toward the back side is regulated by the thrust bearing 52 as in the other embodiments. Therefore, the axial behavior of the pulley 4 is suppressed to be small, and stable belt driving can be obtained. In addition, if the second elastic body 7 is damaged, the pulley 4 can be more reliably prevented from dropping than the stay 6 alone.

  In addition, since the stopper main body 82 is in contact with the flange main body 62 of the stay 6 from the front side, the thrust stopper 8 can compensate the fixing strength of the stay 6 with respect to the support cylinder portion 13 of the hub 1.

1 is a half cross-sectional view showing an embodiment of a torque fluctuation absorbing damper according to the present invention by cutting along a plane passing through its axis O. FIG. FIG. 5 is a half cross-sectional view showing a conventional torque fluctuation absorbing damper cut along a plane passing through its axis O. FIG. 6 is a half cross-sectional view showing another conventional torque fluctuation absorbing damper cut along a plane passing through its axis O.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hub 11 Boss part 12 Disk part 13 Support cylinder part 13a Step part
14 Rim part
17 Engagement protrusion
2 Annular mass
3 First elastic body 4 Pulley 41 Pulley body 42 Front disc part 43 Supported cylinder part 44 Inner flange part
46 engagement hole
51 Radial bearing 52 Thrust bearing 6 Stay 61, 81 Sleeve 62 Flange body 62a Notch 7 Second elastic body 7a, 7b Recess 8 Thrust stopper 82 Stopper body TD Torsional damper part

Claims (3)

An annular mass body (2) is connected to the hub (1) via a first elastic body (3) made of a rubber-like elastic material so as to be capable of relative displacement in the circumferential direction, and the hub (1) or the annular mass body (2). A pulley (4) is supported by a radial bearing (51) on a support cylinder portion (13) formed on the hub (1) located on the inner peripheral side of the first elastic body (3). A rubber-like elastic material is inserted between the inner peripheral flange portion (44) formed on the inner peripheral portion of the pulley (4) and the stay (6) positioned on the outer side in the axial direction. The pulley (4) and the hub (1) or the annular mass (which are connected in the axial direction via the second elastic body (7) and are narrowed by the axial compressive force of the second elastic body (7). axially between opposing surfaces of the 2), thrust bearing (52) is interposed, the support tube portion (1 ) To the thrust stopper (8) is press-fitted, the outer peripheral portion of the thrust stopper (8) comprises a pulley (4) to the torque fluctuation absorbing damper, characterized in that opposed from the axially outside. Relative to the circumferential direction of the hub (1) and the pulley (4), the hub (1) and the pulley (4) are loosely fitted in engagement recesses or engagement holes formed in the hub (1) or the annular mass body (2) with an appropriate clearance in the circumferential direction. The torque fluctuation absorbing damper according to claim 1, characterized in that an engaging projection for limiting the displacement to a predetermined range is formed on the pulley (4). An engagement recess or engagement hole (46) is formed in the inner peripheral flange (44) of the pulley (4), and is loosely fitted in the engagement recess or engagement hole (46) with an appropriate clearance in the circumferential direction. The engaging projection (17) for limiting the relative displacement in the circumferential direction of the hub (1) and the pulley (4) to a predetermined range is provided on the inner surface of the hub (1). The torque fluctuation absorbing damper according to claim 1.

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