JP2004278618A - Torque fluctuation absorbing damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torque fluctuation absorbing damper that can be manufactured at a low cost. <P>SOLUTION: This torque fluctuation absorbing damper is provided with a coupling part 1 comprising a hub 10 installed on a crankshaft, and a flange part 22 extended from a pulley 20 relatively rotatably supported on the outer circumference of the hub 10 toward the front side of the hub 10, elastically connected to each other through a first elastic body 50, and a dynamic vibration absorbing part 2 comprising the hub 10, and a circular mass body 60 disposed on the back side of it, elastically connected to each other through a second elastic body 70. The first elastic body 50 comprises a rubber-like elastic material filled between the hub 10 and the flange part 22 through a small hole 22a in the flange part 22 on the pulley 20 to be vulcanization-bonded. The second elastic body 70 has inner diameter that is smaller than inner diameter of the first elastic body 50, and it comprises the rubber-like elastic material filled between the hub 10 and the circular mass body 60 through a small hole 12b formed in the hub 10 on the inner circumferential side of the flange part 22 to be vulcanization-bonded. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a torque fluctuation absorbing damper used for automobiles, agricultural machines, industrial machines, small boats, and the like, which transmits torque from a drive shaft to another rotating device and absorbs fluctuations in the torque.
[0002]
[Prior art]
A part of the driving force from the engine of the automobile is supplied from a pulley provided at the tip of the crankshaft to an auxiliary device such as an alternator or a water pump through an endless belt. Since the pulley is rotated with the fluctuation, the pulley is provided with a torque fluctuation absorbing damper for absorbing the torque fluctuation and smoothing the transmission torque.
[0003]
As a typical conventional example of this kind of torque fluctuation absorbing damper, there is known a decoupled damper pulley described in Patent Literature 1 below, which is fixed to a shaft end of a crankshaft and integrally rotates. And a coupling section and a dynamic vibration absorbing section attached to the hub. The coupling portion includes a sleeve press-fitted into the inner cylinder portion of the hub and an inner cylinder portion of a pulley having a double cylindrical shape having a U-shaped cross section surrounding the dynamic vibration absorbing portion via a coupling rubber. The inner cylinder of the pulley is connected to the inner periphery of the rim of the hub via a bearing so that it can rotate. The torque input from the crankshaft to the hub is subjected to the shear deformation of the coupling rubber in the torsional direction. While being smoothed by the action, it is transmitted to the pulley. Further, the dynamic vibration absorbing portion is formed by press-fitting the second elastic body between the rim portion of the hub and the annular mass body arranged on the outer periphery thereof, and has a predetermined frequency range where the torsional amplitude of the crankshaft increases. In this case, a resonance control function of reducing the torsional vibration is exhibited by resonating in a phase opposite to the torsional vibration of the crankshaft.
[0004]
[Patent Document 1]
Utility Model Registration No. 2605662 (FIG. 1)
[0005]
[Problems to be solved by the invention]
However, according to the conventional torque fluctuation absorbing damper described in Patent Document 1, a step of vulcanizing and bonding a coupling rubber between a sleeve and a pulley to obtain a coupling portion, and a vulcanization molding of a second elastic body A step of press-fitting the second elastic body between the rim portion of the hub and the annular mass body to assemble the dynamic vibration absorbing portion, and press-fitting the sleeve in the coupling portion to the inner cylinder portion of the hub. A step of incorporating the inner cylindrical portion of the pulley into the inner periphery of the rim portion of the hub via a bearing is required, and therefore, the number of steps is large and the manufacturing cost is high.
[0006]
The present invention has been made in view of the above problems, and a technical problem thereof is to provide a torque fluctuation absorbing damper having a structure that can be manufactured at low cost.
[0007]
[Means for Solving the Problems]
As a means for effectively solving the above-mentioned technical problem, a torque fluctuation absorbing damper according to the invention of claim 1 includes a hub and a pulley supported on the outer periphery of the hub so as to be relatively rotatable from one side in the axial direction of the hub. A coupling part in which the extending flange part is elastically connected via a first elastic body, and a dynamic part in which the hub and an annular mass body arranged on the other side in the axial direction thereof are elastically connected via a second elastic body. A vibration-absorbing portion, wherein the first elastic body is made of a rubber-like elastic material filled and vulcanized and bonded between the hub and the flange portion through a small hole formed in the flange portion; The inner diameter of the second elastic body is smaller than the inner diameter of the first elastic body, and between the hub and the annular mass body through a small hole formed in the hub on the inner peripheral side of the flange portion. Made of a rubber-like elastic material filled and vulcanized.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a cross-sectional view showing an embodiment of a torque fluctuation absorbing damper according to the present invention, cut along a plane passing through an axis thereof. FIG. 2 is a sectional view showing an assembling process of the torque fluctuation absorbing damper of FIG. It is sectional drawing cut | disconnected and shown by the plane which passes through a heart. The “front side” used in the following description refers to the left side in FIGS. 1 and 2, and corresponds to “one side in the axial direction” described in claim 1, and “back side” 1 is a side on the right side in FIGS. 1 and 2 where an unillustrated automobile engine is present, and corresponds to the “other side in the axial direction” described in claim 1.
[0009]
In these figures, reference numeral 10 denotes a hub attached to a shaft end of a crankshaft (not shown) of an automobile engine. The hub 10 is cast from a metal material, and has a boss portion 11 fixed to a crankshaft, a disk portion 12 extending from an end on the front side to an outer peripheral side, and an outer periphery of the disk portion 12. The rim 13 extends to the rear side. A portion near the outer periphery of the front surface of the disk portion 12 is a tapered surface 12a that is receded to the rear side toward the outer periphery. Reference numeral 11a is a key groove formed in a shaft hole on the inner periphery of the boss portion 11.
[0010]
A pulley 20 is arranged on the outer periphery of the rim portion 13 of the hub 10. Is interposed.
[0011]
The holder 30 is formed by stamping and pressing a metal plate, and includes a cylindrical portion 31 fitted on the outer peripheral surface of the rim portion 13 of the hub 10 and a flange portion 32 extending from the rear end to the outer periphery. The bearing 40 is formed of a low friction coefficient synthetic resin material such as PTFE having excellent wear resistance, and is interposed between the cylindrical portion 31 of the holder 30 and the inner peripheral surface of the pulley 20. A cylindrical radial receiving portion 41 and a thrust receiving portion 42 interposed between the flange portion 32 of the holder 30 and the rear end surface of the pulley 20. The bearing 40 supports the pulley 20 in the radial receiving portion 41 in a state where relative eccentricity between the hub 10 and the pulley 20 is regulated, and allows the pulley 20 to be relatively displaceable in the circumferential direction with respect to the hub 10. At 42, the relative axial behavior of the hub 10 and the pulley 20 is regulated.
[0012]
The pulley 20 is manufactured by press-forming a metal plate, has a poly-V groove 21 formed on the outer peripheral surface thereof, and has a flange portion 22 extending from the front end to the inner periphery. The flange portion 22 is located on the front side of the tapered surface 12 a formed on the disk portion 12 of the hub 10.
[0013]
The flange portion 22 of the pulley 20 is elastically connected via a first elastic body 50 to the tapered surface 12a of the disk portion 12 of the hub 10 that faces the pulley 20 in the axial direction, thereby forming the coupling portion 1. ing. The coupling unit 1 transmits the driving torque input from the crankshaft to the hub 10 to the pulley 20 while smoothing the driving torque by the circumferential shearing action of the first elastic body 50.
[0014]
The first elastic body 50 is formed by vulcanization molding with a rubber-like elastic material having excellent heat resistance, cold resistance and mechanical strength, and its front end is closer to the outer periphery of the flange portion 22 of the pulley 20. The rear end portion is integrally vulcanized and bonded to the disk portion 12 of the hub 10. The first elastic body 50 has the tapered surface 12a so that when subjected to circumferential shearing deformation between the hub 10 and the pulley 20, the shearing stress is substantially uniform between the inner peripheral side and the outer peripheral side. Thereby, the thickness in the connection direction (axial direction) increases toward the outer peripheral side.
[0015]
A plurality of engaging projections 23 protruding toward the rear side are formed at equal intervals in the circumferential direction at an end on the back side of the pulley 20. In the engagement notch 32a formed in the groove 32, it is loosely fitted with an appropriate clearance on both sides in the circumferential direction. That is, the engagement protrusion 23 and the engagement notch 32a limit the relative displacement of the hub 10 and the pulley 20 in the circumferential direction to a predetermined range due to the mutual interference.
[0016]
An annular mass body 60 is arranged concentrically on the back side of the disk portion 12 of the hub 10, in other words, on the inner peripheral side of the rim portion 13 of the hub 10, and the annular mass body 60 and the disk portion 12 Are elastically connected via the second elastic body 70 to form the dynamic vibration absorber 2. The natural frequency of the torsional direction is determined by the circumferential inertial mass of the annular mass body 60 and the circumferential shear spring constant of the second elastic body 70 in a predetermined frequency range in which the torsion angle of the crankshaft is maximized. In other words, the tuning is performed so as to match the natural frequency of the crankshaft in the torsional direction.
[0017]
The annular mass body 60 is manufactured by casting a metal material such as an iron-based material or the like, and the surface of the annular mass body 60 to be bonded to the second elastic body 70 has a taper that retreats from the disk portion 12 of the hub 10 toward the outer peripheral side. It is a surface 60a. The second elastic body 70 is made of a rubber-like elastic material having excellent heat resistance, cold resistance and mechanical strength, and is integrally vulcanized between the tapered surface 60a and the back surface of the disk portion 12. The taper surface 60a allows the connecting direction to be substantially uniform between the inner peripheral side and the outer peripheral side when the hub 10 and the annular mass body 60 are subjected to circumferential shear deformation. The shape is such that the thickness in the (axial direction) increases toward the outer peripheral side.
[0018]
The inner diameter of the annular mass body 60 is smaller than the inner diameter of the flange portion 22 of the pulley 20, and accordingly, the second elastic body 70 is entirely on the inner peripheral side compared to the first elastic body 50. Exists. A small hole 22a is formed in the flange portion 22, and a part 51 of a rubber-like elastic material constituting the first elastic body 50 is filled in the small hole 22a. In the disk portion 12 of the hub 10, a small hole 12 b penetrating in the axial direction is formed in a portion closer to the inner periphery than the bonding surface (tapered surface 12 a) with the first elastic body 50. A part 71 of the rubber-like elastic material constituting the inner peripheral portion of the bielastic body 70 is also filled in the small holes 12b.
[0019]
In the torque fluctuation absorbing damper having the above configuration, as shown in FIG. 2, the coupling portion 1 and the dynamic vibration absorbing portion 2 form one vulcanized molded body A. In other words, this vulcanized molded body A has a hub 10, a pulley 20, and an annular mass body 60 concentrically set in a mold (not shown), and a tapered surface 12 a of a disk portion 12 of the hub 10. In the annular cavity defined by the mold between the pulley 20 and the flange 22 of the pulley 20 opposed to the axial direction, a small hole 22a formed in the flange 22 of the pulley 20 is formed. By filling the vulcanized rubber material, the first elastic body 50 is vulcanized and bonded to the tapered surface 12a and the flange portion 22 at the same time as vulcanization molding, while the back surface of the disk portion 12 and the axially opposed surface thereof The unvulcanized rubber material is filled into the annular cavity defined by the mold between the tapered surface 60a of the annular mass body 60 through the small holes 12b formed in the disk portion 12. By Two elastic body 70 is obtained by vulcanization bonded to the tapered surface 60a and the disc part 12 at the same time as vulcanization.
[0020]
At this time, since the rubber material charging path via the small hole 22a of the flange portion 22 of the pulley 20 and the rubber material charging path via the small hole 12b of the disk portion 12 of the hub 10 are different, the first elastic body 50 is formed. Different materials can be used for the rubber material for forming the second elastic body 70 and the rubber material for forming the second elastic body 70. Therefore, for example, a rubber-like elastic material having excellent heat resistance is selected as the second elastic body 70 on the rear side, which is susceptible to radiant heat of the engine, and the first elastic body 50 on the front side for transmitting torque is, for example, mechanical. Therefore, it is possible to select an optimum material for each condition, such as selecting a rubber-like elastic material having excellent mechanical strength.
[0021]
In the above-described molding step, the small hole 12b serving as the injection port of the unvulcanized rubber material of the second elastic body 70 is provided with the small hole 22a serving as the injection port of the unvulcanized rubber material of the first elastic body 50. Is located on the inner peripheral side of the flange portion 22 of the pulley 20 and the small holes 22a and 12b are exposed in the same direction (front side), so that the vulcanization of the first elastic body 50 is performed. Molding (vulcanization adhesion) and vulcanization molding (vulcanization adhesion) of the second elastic body 70 can be performed simultaneously. Therefore, only one molding step is required, and the holder 30 and the bearing 40 are simply interposed between the rim portion 13 of the hub 10 and the pulley 20 in the obtained vulcanized molded body A from the back side. The torque fluctuation absorbing damper shown in FIG. 1 can be easily assembled.
[0022]
As described above, the small holes 22a of the flange portion 22 of the pulley 20 and the small holes 12b of the disk portion 12 of the hub 10 are used as material injection ports for forming the first elastic body 50 and the second elastic body 70, respectively. However, since the part 51 of the first elastic body 50 and the part 71 of the second elastic body 70 are formed so as to fill the inside thereof, the joining of the flange portion 22 and the first elastic body 50 is performed. The strength and the bonding strength between the disk portion 12 and the second elastic body 70 are high.
[0023]
The torque fluctuation absorbing damper is rotated together with the crankshaft by mounting the boss 11 of the hub 10 on the shaft end of a crankshaft (not shown) of the engine. The torque of the crankshaft is transmitted from the hub 10 to the pulley 20 via the first elastic body 50 by the coupling unit 1, and further, through a belt (not shown) wound around the pulley 20, a cooling fan or the like. Is transmitted to a rotating shaft of an auxiliary machine such as an alternator.
[0024]
The engine is driven while repeating the intake, compression, explosion, and exhaust strokes, converting the reciprocating motion of the piston into the rotational motion of the crankshaft. Although torque fluctuations occur, the torque fluctuations are converted into thermal energy by the first elastic body 50 in the coupling portion 1 being sheared in the torsional direction by a low spring, so that the torque transmitted to the belt is smoothed. Be converted to Further, the dynamic vibration absorber 2 resonates in the circumferential direction in a frequency range where the torsional angle due to the torsional vibration of the crankshaft is maximum, and the torque due to the resonance is opposite in direction to the torque of the input vibration. The peak of the twist angle of the shaft can be effectively reduced.
[0025]
The radial load acting on the pulley 20 due to the tension of the V-belt is supported by the cylindrical portion 31 of the holder 30 pressed into the rim portion 13 of the hub 10 via the radial receiving portion 41 of the bearing 40. For this reason, the eccentricity of the pulley 20 with respect to the hub 10 is prevented, and the first elastic body 50 in the coupling portion 1 does not receive a shear load in the radial direction, so that its durability can be improved.
[0026]
When the relative displacement (torsion angle) between the hub 10 and the pulley 20 in the circumferential direction reaches a predetermined value due to input of a large torque fluctuation or the like, the engagement protrusion 23 formed on the pulley 20 and the holder 30 Since the engagement notch 32a formed in the flange 32 interferes in the circumferential direction, the relative displacement of the hub 10 and the pulley 20 in the circumferential direction is limited, and the excessive elastic deformation of the first elastic body 50 is prevented.
[0027]
【The invention's effect】
In the torque fluctuation absorbing damper according to the first aspect of the present invention, the first elastic body in the coupling portion and the second elastic body in the dynamic vibration absorbing portion are vulcanized and bonded to both sides in the axial direction of the hub. Will be less. In addition, since the rubber material for molding the first elastic body and the rubber material for molding the second elastic body can be filled and molded simultaneously from the same direction, it can be manufactured at low cost.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a preferred embodiment of a torque fluctuation absorbing damper according to the present invention, cut along a plane passing through an axis thereof.
FIG. 2 is a cross-sectional view showing an unassembled state of the torque fluctuation absorbing damper of FIG. 1 cut along a plane passing through an axis thereof.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Coupling part 2 Dynamic vibration absorption part 10 Hub 11 Boss part 12 Disk part 12b, 22a Small hole 13 Rim part 20 Pulley 21 Poly V groove 22 Flange part 23 Engagement projection 30 Holder 31 Tubular part 32 Flange part 32a Engage Notch 40 Bearing 41 Radial receiving part 42 Thrust receiving part 50 First elastic body 60 Annular mass 70 Second elastic body A Vulcanized molded body

Claims (1)

A flange (22) extending from the pulley (20) supported on the hub (10) and the outer periphery thereof so as to be relatively rotatable toward one side in the axial direction of the hub (10) is elastically interposed via a first elastic body (50). Dynamic coupling in which a coupling part (1) connected to the shaft and the hub (10) and an annular mass body (60) arranged on the other side in the axial direction are elastically connected via a second elastic body (70). (2), wherein the first elastic body (50) is provided between the hub (10) and the flange portion (22) through a small hole (22a) opened in the flange portion (22). The second elastic body (70) has an inner diameter smaller than the inner diameter of the first elastic body (50), and is made of a rubber-like elastic material filled and vulcanized and bonded. ) Through a small hole (12b) formed in the hub (10) on the inner peripheral side of the hub (10). 0) the torque fluctuation absorbing damper, characterized in that it consists of rubber-like elastic material in which wear vulcanization filled between the annular mass body (60).

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