JP2015129543A - Torque fluctuation absorbing damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque fluctuation absorbing damper lightweight and improved in abrasion resistance and corrosion resistance.SOLUTION: In a torque fluctuation absorbing damper, an annular mass body 3 is connected to an outer periphery of a hub 1 through a first elastic body 6, and a pulley 7 rotatably supported by the annular mass body 3 through a bearing 8 is connected to the annular mass body 3 through a second elastic body 9. At least one of the annular mass body 3 and the pulley 7 is made of aluminum or aluminum alloy surface-hardened by hard alumite treatment or hard chromium-plating treatment.

Description

  The present invention relates to torque fluctuation absorption that transmits rotational torque from a drive shaft of a rotating device such as a crankshaft of an automobile engine to other rotating devices, absorbs fluctuations in the rotational speed, and absorbs vibrations of the drive shaft. Regarding dampers.

  A pulley provided at the tip of a crankshaft of an automobile internal combustion engine is provided with a torque fluctuation absorbing mechanism for absorbing torque fluctuation and smoothing transmission torque. This torque fluctuation absorbing damper includes a hub made of cast iron or sheet metal press-molded body that is attached to the shaft end of a crankshaft of an internal combustion engine for automobiles and rotates integrally, a dynamic damper portion, and a coupling portion. The damper portion has a structure in which a hub made of cast iron or a sheet metal press-formed body and an annular mass body made of cast iron or the like disposed on the outer periphery thereof are elastically connected via a first elastic body. Further, the coupling portion includes a pulley made of cast iron or a sheet metal press-formed body supported on the outer periphery of the hub or the annular mass body via a synthetic resin bearing, and the annular mass body or the hub. It has a structure that is elastically connected through the body.

  This torque fluctuation absorbing damper is a torsion of the crankshaft due to a dynamic vibration absorption effect caused by a dynamic damper portion composed of a first elastic body and an annular mass body resonating in a circumferential direction in a predetermined frequency range. In addition to reducing the vibration peak, the driving torque input from the crankshaft to the hub is transmitted to the pulley while absorbing torque fluctuations due to the circumferential shear deformation of the second elastic body in the coupling part. is there.

  As a typical prior art of the torque fluctuation absorbing damper, for example, there is one disclosed in the following prior art document.

JP 2008-2613 A

  Conventionally, castings and steel plates are frequently used for the parts of this type of torque fluctuation absorbing damper, and since the number of parts is large, the weight of the product is large, which causes the fuel consumption to deteriorate. Here, if aluminum is used as a material for these parts, it is possible to reduce the weight, but aluminum has lower wear resistance compared to castings and steel plates, and is wound around the poly V groove of the pulley. Further, wear of the poly V groove due to friction with the V belt and wear due to sliding with bearings and iron parts may occur, and the product function may be impaired at an early stage. In addition, there is a problem that in a part where aluminum parts and iron parts are mixed, electrolytic corrosion occurs due to a difference in ionization tendency when water or the like enters.

  The present invention has been made in view of the above points, and a technical problem thereof is to provide a torque fluctuation absorbing damper that is lightweight and has improved wear resistance and corrosion resistance.

  As a means for effectively solving the technical problem described above, a torque fluctuation absorbing damper according to the invention of claim 1 includes an annular mass connected to an outer periphery of a hub via a first elastic body, and the annular mass. In a torque fluctuation absorbing damper in which a pulley rotatably supported by a body via a bearing is connected to the annular mass via a second elastic body, at least one of the annular mass and the pulley is surface hardened It consists of a treated aluminum or aluminum alloy.

  A torque fluctuation absorbing damper according to a second aspect of the present invention is the configuration described in the first aspect, wherein the surface hardening treatment is performed by hard alumite treatment or hard chrome plating treatment.

  According to a third aspect of the present invention, in the torque fluctuation absorbing damper, in the configuration described in the first or second aspect, both the annular mass body and the pulley are made of aluminum or an aluminum alloy, and one of them slides with the bearing. The member is subjected to surface hardening treatment, and the other member that does not slide with the bearing is subjected to rust prevention treatment by a surface treatment means other than the surface hardening treatment.

  According to a fourth aspect of the present invention, there is provided the torque fluctuation absorbing damper according to any one of the first to third aspects, wherein the bearing is held by one member made of aluminum or an aluminum alloy among the pulley and the annular mass body. At the same time, the one member is retained by a projection formed by plastic working.

  According to the torque fluctuation absorbing damper according to the present invention, weight reduction is achieved by using surface-treated aluminum or aluminum alloy for at least one of the annular mass body and the pulley, and wear resistance is ensured. It is possible to effectively suppress the occurrence of galvanic corrosion and rust due to water intervening between the system parts. And since aluminum or aluminum alloy is excellent in heat conductivity, heat dissipation can improve and it can improve durability of a 1st elastic body or a 2nd elastic body.

  When both the annular mass body and the pulley are made of aluminum or an aluminum alloy, only one member that slides with the bearing is subjected to surface hardening treatment, and the other one that does not slide with the bearing. If the member is subjected to a rust prevention treatment by an inexpensive surface treatment means other than the surface hardening treatment, an increase in cost can be suppressed.

  In addition, by making the pulley made of aluminum or an aluminum alloy, a protrusion for preventing the radial bearing arranged on the inner peripheral surface from coming off can be easily provided by plastic working.

1 is a cross-sectional perspective view showing a first embodiment of a torque fluctuation absorbing damper according to the present invention by cutting along a plane passing through an axis. It is a fragmentary sectional perspective view which cut | disconnects and shows the coupling part in 1st embodiment in the plane which passes along an axial center. It is a section perspective view which cuts and shows a 2nd embodiment of a torque change absorption damper concerning the present invention by a plane which passes along an axis.

  Hereinafter, a preferred embodiment of a torque fluctuation absorbing damper according to the present invention will be described with reference to the drawings. In the following description, “front side” means the left side in each figure and the front side of the vehicle, and “back side” means the right side in each figure and there is an internal combustion engine (not shown). That is the side.

  FIG. 1 shows a first embodiment. Reference numeral 1 denotes a hub attached to a crankshaft (not shown) of an automobile internal combustion engine. The hub 1 is made of cast iron material, aluminum or an aluminum alloy, and has a boss portion 1a into which the shaft end of the crankshaft is inserted, and from the front end portion of the boss portion 1a to the outer diameter side. An annular stepped portion 1b that extends and an outer peripheral cylindrical portion 1c that extends concentrically with the boss portion 1a from the outer periphery toward the front side. A key groove 1d is formed on the inner peripheral surface of the boss 1a.

  On the outer peripheral side of the outer peripheral cylindrical portion 13 of the hub 1, a sleeve 2, an annular mass body 3 and a pulley angle 4 fitted on the outer peripheral surface thereof, and a coupling angle 5 fitted on the outer peripheral surface of the annular mass body 3. Is arranged. The sleeve 2 is made of iron and has a simple cylindrical shape. The first elastic body 6 is integrally vulcanized and bonded between the sleeve 2 and the outer peripheral cylindrical portion 13 of the hub 1.

  The annular mass 3 is made of aluminum or an aluminum alloy, and has an inner peripheral cylindrical portion 3a press-fitted to the outer peripheral surface near the front surface of the sleeve 2, and a disk portion 3b developed from the position closer to the front surface toward the outer diameter side. Further, a double cylindrical shape including a supporting cylindrical portion 3c extending from the vicinity of the outer diameter portion of the disk portion 3b to the back side is formed. In addition, the support cylinder portion 3c is formed with a plurality of thick portions 3d having an increased radial thickness so as to ensure a required inertial mass in a circumferentially uniform manner.

  The pulley angle 4 is an iron press-molded body, and includes an attachment tube portion 4a press-fitted to the outer peripheral surface near the back surface of the sleeve 2, and a support flange portion 4b developed in a disk shape from an end portion on the back surface side. The cross section is substantially L-shaped.

  The coupling angle 5 is an iron press-molded body, and the mounting cylinder part 5a press-fitted on the outer peripheral surface of the inner peripheral cylinder part 3a of the annular mass 3 and the front side end part thereof falls down to the front side. It consists of the outward flange part 5b developed in the shape of a conical surface. In addition, the inner surface of the disk part 3b of the annular mass 3 located on the front side of the outward flange part 5b of the coupling angle 5 is also formed in a conical surface shape corresponding to the outward flange part 5b.

  The first elastic body 6 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, and is attached to a mold (not shown). The hub 1 and the sleeve 2 are set concentrically with each other, and an unvulcanized rubber material is formed in a cavity defined between the outer peripheral surface of the outer peripheral cylindrical portion 1c of the hub 1 and the inner peripheral surface of the sleeve 2 by clamping. By being heated and pressurized, the resin is vulcanized and formed into an annular shape (cylindrical shape) and simultaneously vulcanized and bonded to the outer peripheral surface of the outer peripheral cylindrical portion 1c and the inner peripheral surface of the sleeve 2.

  The sleeve 2, the annular mass body 3, the pulley angle 4, the coupling angle 5, and the first elastic body 6 constitute a dynamic damper portion D, and the dynamic damper portion D is integrally fitted to each other. A predetermined frequency range in which the torsion angle of the crankshaft is maximized by the inertial mass due to the sleeve 2, the annular mass body 3, the pulley angle 4 and the coupling angle 5, and the spring constant of the first elastic body 6, in other words, the crank It is tuned to match the natural frequency of the shaft in the torsional direction.

  Reference numeral 7 is a pulley. The pulley 7 is made of aluminum or an aluminum alloy, and includes a pulley body 7a, an inward flange portion 7b extending from an end portion on the back surface side to the inner diameter side of the front side of the support flange portion 4b of the pulley angle 4; It consists of a supported cylinder portion 7c that extends from the outer peripheral portion of the front end portion of the pulley body 7a and is supported on the outer periphery of the support cylinder portion 3c of the annular mass 3 via a radial bearing 8.

  The radial bearing 8 is made of a synthetic resin material having a low friction coefficient and having excellent wear resistance such as PTFE (polytetrafluoroethylene). The radial bearing 8 has a cylindrical shape in which one circumferential direction is cut. It arrange | positions at the inner peripheral surface of the to-be-supported cylinder part 7c, and is contacting the outer peripheral surface of the support cylinder part 3c of the cyclic | annular mass 3 so that sliding is possible.

  A poly V groove 7d is formed on the outer peripheral surface of the pulley main body 7a, and a V belt (not shown) is wound around the pulley main body 7a. Further, a labyrinth gap L located outside the radial bearing 8 is formed between the front end portion of the supported cylinder portion 7 c and the outer diameter end portion of the disk portion 3 b in the annular mass body 3.

  The outward flange portion 5b of the coupling angle 5 fitted to the annular mass body 3 and the inward flange portion 7b of the pulley 7 facing in the axial direction from the back side thereof are substantially cylindrical in the hollow portion of the annular mass body 3. The second elastic body 9 extending in a shape is elastically coupled so as to be capable of relative displacement in the circumferential direction, and thereby a coupling portion C is configured.

  The second elastic body 9 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, and is attached to a mold (not shown). The coupling angle 5 and the pulley 7 are set concentrically, and a cylindrical cavity is defined between the outward flange portion 5b of the coupling angle 5 and the inward flange portion 7b of the pulley 7 by clamping. The unvulcanized rubber material is filled, heated and pressurized, and vulcanized and bonded to the outward flange portion 5b and the inward flange portion 7b simultaneously with the vulcanization molding.

  The second elastic body 9 transmits the driving torque input from the crankshaft to the hub 1 to the pulley 7 while being smoothed by circumferential shear deformation. The torque fluctuation of the crankshaft is less than the idling. Since the second elastic body 9 has a low spring constant, increases the allowable deformation amount in the torsional direction, and secures a torque transmission force, the second elastic body 9 has an axial direction and a diameter. The wall thickness in the direction is large.

  A rubber layer 9 a that wraps around from the second elastic body 9 is formed on the front side of the outward flange portion 5 b of the coupling angle 5, and is in close contact with the inner surface of the disk portion 3 b of the annular mass 3.

  A thrust bearing 10 is interposed between the support flange portion 4 b of the pulley angle 4 and the inward flange portion 7 b of the pulley 7. The thrust bearing 10 is made of a synthetic resin material having a low friction coefficient and excellent wear resistance, such as PTFE, like the radial bearing 8, and is formed into a flat washer shape.

  The annular mass body 3 and the pulley 7 made of aluminum or an aluminum alloy are subjected to surface hardening treatment by hard anodizing or hard chrome plating.

  The torque fluctuation absorbing damper having the above-described configuration is rotated together with the crankshaft of the automobile internal combustion engine, and its driving torque is compensated through a V belt wound around the pulley body 7a (poly V groove 7d) of the pulley 7. It is transmitted to the rotating shaft of the machine. And since the annular mass body 3 and the pulley 7 consist of aluminum or aluminum alloy which is a light metal, the weight of a product can be reduced and it can contribute to the improvement of a fuel consumption.

  The annular mass 3 is light in weight because the plurality of thick portions 3d are formed in the support cylinder portion 3c in a uniform manner in the circumferential direction, so that the center of gravity is relatively unevenly distributed on the outer peripheral side. Nevertheless, a sufficient inertial mass is ensured, and therefore a sufficiently large vibration damping torque can be obtained to counteract the input torque of the crankshaft torsional vibration.

  Here, the dynamic damper portion D resonates in the circumferential direction in the frequency range where the torsion angle is maximum due to the resonance of the crankshaft, and the direction of the torque resulting from the resonance is opposite to the torque of the input vibration. Such dynamic vibration absorbing action can effectively reduce the peak of torsional angle due to crankshaft resonance.

  In addition, torque fluctuations that are conspicuously generated in the crankshaft in the low rotation range are transferred from the hub 1 through the first elastic body 6 to the sleeve 2 and the annular mass body 3 integrated therewith, the pulley angle 4 and the coupling angle 5. Then, it is further transmitted from the coupling angle 5 to the pulley 7 via the second elastic body 9. Here, since the circumferential elastic spring constant of the second elastic body 9 is remarkably low, the second elastic body 9 is repeatedly sheared and deformed in the circumferential direction according to the input torque fluctuation, and converts the torque fluctuation into heat energy. For this reason, the transmission torque to the V belt wound around the pulley body 7a (poly V groove 7d) of the pulley 7 is smoothed.

  Here, along with the dynamic vibration absorbing action of the dynamic damper portion D, the first elastic body 6 generates heat by repeatedly undergoing shear deformation in the circumferential direction between the outer peripheral cylindrical portion 13 and the sleeve 2 of the hub 1, Part of the heat is conducted from the sleeve 2 to the annular mass 3 and is released from the annular mass 3 into the outside air. At this time, the annular mass 3 has a wide contact surface with the outside air in the disk portion 3b in addition to being made of aluminum or an aluminum alloy having excellent thermal conductivity, and thus heat radiation to the outside air is performed well. Therefore, deterioration of the first elastic body 6 due to heat accumulation can be effectively prevented.

  On the other hand, in the coupling part C, the second elastic body 9 generates heat by repeatedly undergoing shear deformation in the circumferential direction between the coupling angle 5 and the inward flange part 7b of the pulley 7, and a part of the heat is generated. Is transmitted to the inward flange portion 7b of the pulley 7, or another part of the heat is also transferred to the annular mass 3 through the coupling angle 5, and the inward flange portion 7b and It is discharged from the annular mass body 3 into the outside air. At this time, in addition to the pulley 7 and the annular mass 3 being made of aluminum or aluminum alloy having excellent thermal conductivity, wide contact with the outside air at the disk portion 3b of the annular mass 3 and the inward flange portion 7b of the pulley 7 Since it has a surface, heat radiation to the outside air is favorably performed. Therefore, deterioration of the second elastic body 9 due to heat accumulation can be effectively prevented.

  Further, a part of the air existing in the annular space S surrounded by the annular mass 3, the pulley 7, and the second elastic body 9 is supported by the radial bearing 8 and the annular mass 3 by thermal expansion when the temperature rises. It goes outside through the gap of the sliding part with the part 3c, and external air is taken in through the gap of the said sliding part by cooling shrinkage at the time of the temperature fall after that. When the outside air is taken in, foreign matters such as dust adhering to the labyrinth gap L on the outer side of the radial bearing 8 may be sucked and damage the sliding portion. On the other hand, in the illustrated embodiment, since the heat dissipation of the annular mass 3 and the pulley 7 is high as described above, the temperature difference between cold and hot becomes small. It is possible to reduce the negative pressure at the time of lowering and suppress the entry of dust and the like.

  Since the pulley 7 is surface hardened by hard alumite treatment or hard chrome plating, the inward flange is caused by wear of the poly V groove 7d of the pulley body 7a due to fine slip of the V belt and sliding with the thrust bearing 10. Wear of the portion 7b is effectively suppressed. Similarly, since the annular mass body 3 is also surface hardened by hard alumite treatment or hard chrome plating, wear of the outer peripheral surface of the support cylinder portion 3c due to sliding with the radial bearing 8 is effectively suppressed.

  Further, the fitting surface between the sleeve 2 and the inner circumferential cylindrical portion 3a of the annular mass body 3 is in contact with different metals, but the inner circumferential cylindrical portion of the annular mass body 3 that has been subjected to hard alumite treatment or hard chrome plating treatment. Since the surface of 3a consists of a hard and highly insulating film, it is possible to effectively prevent electrolytic corrosion when moisture intervenes with the iron sleeve 2.

  Moreover, since aluminum or aluminum alloy is easily plastically processed, after the radial bearing 8 is arranged on the inner periphery of the supported cylinder portion 7c in the pulley 7, as shown in FIG. The protrusion 7e for preventing the radial bearing 8 from coming off can be easily formed by crushing the end portion in the axial direction by punching at a plurality of locations in the circumferential direction to cause buckling deformation.

  Next, FIG. 3 shows a second embodiment of the torque fluctuation absorbing damper according to the present invention. In the second embodiment, the difference from the first embodiment described above will be described. The supported cylindrical portion 7c of the pulley 7 extends from the inner peripheral portion of the front end portion of the pulley body 7a. The support cylinder portion 3c of the annular mass 3 extends so as to surround the outer peripheral side of the supported cylinder portion 7c of the pulley 7, and the end on the back side thereof extends in the axial direction via the pulley body 7a and the labyrinth gap L. The radial bearings 8 that face each other and are arranged on the inner peripheral surface of the support cylinder portion 3 c of the annular mass 3 are slidably in contact with the outer peripheral surface of the supported cylinder portion 7 c of the pulley 7. And the some thick part 3d formed in the support cylinder part 3c of the cyclic | annular mass body 3 at equal circumferential direction is thick (large diameter) to an outer-diameter direction.

  The annular mass 3 and the pulley 7 are both made of aluminum or an aluminum alloy. Among these, the pulley 7 is subjected to surface hardening treatment by hard alumite treatment or hard chrome plating, whereas the annular mass body. No. 3 is surface-treated by chromic acid treatment or the like to improve corrosion resistance and prevent electrolytic corrosion.

  Others can be basically configured similarly to the first embodiment.

  According to the torque fluctuation absorbing damper of the second embodiment, the effect similar to that of the first embodiment is realized, and the sliding surfaces of the radial bearing 8 and the thrust bearing 10 are made to slide on the belt. By concentrating on the pulley 7 having the surface (poly V groove 7d), expensive hard anodized treatment or hard chrome plating considering the improvement of wear resistance in addition to the improvement of corrosion resistance and prevention of electric corrosion is only on the pulley 7. The annular mass body 3 that does not have a sliding portion may be subjected to surface treatment by inexpensive chromic acid treatment or the like, so that specifications with reduced costs can be realized.

  That is, since the pulley 7 is surface hardened by hard alumite treatment or hard chrome plating, wear of the poly V groove 7d of the pulley body 7a due to fine slip of the V belt, or inward flange due to sliding with the thrust bearing 10 Wear of the portion 7b and wear of the outer peripheral surface of the outer cylindrical portion 7c due to sliding with the radial bearing 8 are effectively suppressed.

  The fitting surface between the sleeve 2 and the inner circumferential cylindrical portion 3a of the annular mass body 3 is in contact with a dissimilar metal, but the inner circumferential cylindrical portion 3a of the annular mass body 3 surface-treated by chromic acid treatment or the like is used. Since the surface is made of a film having a high rust prevention ability, it is possible to effectively prevent electrolytic corrosion with the iron sleeve 2.

  In the second embodiment, the thick portion 3d of the annular mass 3 is present on the outer peripheral side of the supported cylindrical portion 7c of the pulley 7 and the radial bearing 8, so that the center of gravity of the annular mass 3 is the first. Since it is unevenly distributed on the outer peripheral side as compared with one embodiment, a larger inertial mass can be secured.

  Also in this embodiment, the back side end portions of the support cylinder portion 3c of the annular mass 3 holding the radial bearing 8 on the inner periphery are crushed axially by punches at a plurality of locations in the circumferential direction. By bending and deforming, a projection (not shown) similar to FIG. 2 for preventing the radial bearing 8 from coming off can be easily formed.

1 Hub 2 Sleeve 3 Annular Mass 4 Pulley Angle 5 Coupling Angle 6 First Elastic Body 7 Pulley 8 Radial Bearing 9 Second Elastic Body 9
10 Thrust bearing

Claims (4)

  An annular mass body is connected to the outer periphery of the hub via a first elastic body, and a pulley rotatably supported by the annular mass body via a bearing is connected to the annular mass body via a second elastic body. The torque fluctuation absorbing damper according to claim 1, wherein at least one of the annular mass body and the pulley is made of surface-hardened aluminum or an aluminum alloy.   2. The torque fluctuation absorbing damper according to claim 1, wherein the surface hardening treatment is performed by hard alumite treatment or hard chrome plating treatment.   Both the annular mass body and the pulley are made of aluminum or an aluminum alloy. Of these, one member that slides with the bearing is subjected to surface hardening treatment, and the other member that does not slide with the bearing is subjected to surface treatment means other than the surface hardening treatment. The torque fluctuation absorbing damper according to claim 1 or 2, wherein the torque fluctuation absorbing damper is subjected to rust prevention treatment.   The bearing is held by one member made of aluminum or an aluminum alloy among the pulley and the annular mass body, and is retained by a protrusion formed by plastic working on the one member. 4. The torque fluctuation absorbing damper according to any one of 3 above.

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