JP4032228B2 - Torque fluctuation absorbing damper - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a torque fluctuation absorbing damper that transmits driving torque in an internal combustion engine or the like to a rotating device and absorbs fluctuations in the torque.
[0002]
[Prior art]
A part of the driving force from the internal combustion engine of the automobile is applied to an auxiliary device such as an alternator or a water pump from an pulley provided at the tip of the crankshaft via an endless belt. The pulley is provided with a torque fluctuation absorbing damper for absorbing the torque fluctuation and smoothing the transmission torque because it is rotated with the torque fluctuation caused by the compression, explosion (expansion) and exhaust strokes.
[0003]
A typical prior art of this type of torque fluctuation absorbing damper is disclosed in, for example, Utility Model Registration No. 2606562. The torque fluctuation absorbing damper (decoupled damper pulley) according to the prior art includes a hub that is attached to the shaft end of the crankshaft and rotates integrally, and a dynamic vibration absorber and a coupling portion that are attached to the hub. The dynamic vibration absorbing portion has a structure in which an annular mass body is attached to the outer periphery of the rim portion of the hub via a damper rubber. The coupling portion has a structure in which a hub and a pulley supported on the rim portion so as to be relatively rotatable via a bearing are connected via an annular coupling rubber. The relative torsional displacement of the pulley is limited by the engagement of a stopper pin attached to the annular mass and a long hole formed in the pulley.
[0004]
That is, the torque fluctuation absorbing damper transmits the driving torque of the internal combustion engine inputted from the crankshaft to the hub to the pulley while absorbing the driving torque of the coupling rubber by the torsional direction shear deformation action of the coupling rubber. A vibration damping function that reduces the torsional vibration by resonating the dynamic vibration absorption part made of mass body in a phase opposite to the torsional vibration of the crankshaft in a predetermined frequency range where the torsional amplitude of the crankshaft becomes large To demonstrate.
[0005]
[Problems to be solved by the invention]
However, according to the conventional torque fluctuation absorbing damper, since the coupling rubber has a simple annular shape continuous in the circumferential direction, shearing in the torsional direction when torque fluctuation is input between the hub and the pulley. The spring constant is relatively high, in other words, the rigidity is large. Therefore, the deformation amount of the coupling rubber with respect to the input of torque fluctuation is small, and sufficient torque fluctuation absorption performance cannot be obtained.
[0006]
When excessive torque fluctuations are input, the amount of relative displacement in the torsional direction of the hub and pulley is limited by the engagement of the stopper pin attached to the annular mass and the elongated hole formed in the pulley, and excessive deformation of the coupling rubber However, at this time, there is a problem that a contact sound between the stopper pin and the long hole of the pulley is generated. Moreover, in the state where the relative displacement in the torsional direction of the hub and the pulley is stopped by the contact between the stopper pin and the long hole of the pulley, the torque fluctuation absorbing function is lost, that is, about the increase in torque fluctuation after the contact with the long hole of the pulley. , Which could hardly be absorbed.
[0007]
The present invention has been made in view of the above-described problems, and its technical problem is to prevent the generation of contact noise by the coupling rubber deformation limiting means when excessive torque fluctuation is input, and torque fluctuation It is to improve the absorption performance.
[0008]
[Means for Solving the Problems]
As a means for effectively solving the technical problem described above, a torque fluctuation absorbing damper according to the present invention includes a coupling rubber between a hub attached to a rotating shaft and a pulley that can rotate relative to the hub. The coupling rubber is provided with a plurality of gaps at predetermined intervals in the circumferential direction, and the gaps are provided at predetermined intervals in the circumferential direction on the hub or the pulley , respectively. The coupling rubber is loosely fitted to the stopper with a predetermined clearance in the circumferential direction, and the coupling rubber extends from the radial portion of the hub and its outer periphery, and from the radial portion of the pulley and its inner peripheral end portion. And a supported cylinder part supported by a mounting cylinder part at an inner peripheral end part of the hub on the inner peripheral side of the rim part via a bearing, and an inner peripheral surface of the rim part of the hub and the pooh. Those that are integrally bonded to the outer peripheral surface of the support cylinder portion. That is, the coupling rubber has a gap portion so that the spring constant in the circumferential direction is lowered, and the stopper limits the relative displacement in the circumferential direction of the hub and the pulley by contact with the coupling rubber.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a sectional view showing a preferred embodiment of a torque fluctuation absorbing damper according to the present invention by cutting along a plane orthogonal to the axis O, and FIG. 2 is a sectional view taken along the line II-O-II ′ in FIG. FIG. The “front side” used in the following description refers to the left side in FIG. 2, the “back side” refers to the right side in FIG. The “circumferential direction” is a circumferential direction around the axis O.
[0010]
As shown in FIGS. 1 and 2, the torque fluctuation absorbing damper of the present embodiment includes a hub 1 attached to a shaft end of a crankshaft of an automotive internal combustion engine, and a dynamic vibration absorber provided on the outer peripheral side of the hub 1. Part 2 and coupling part 3.
[0011]
The hub 1 is manufactured by punching a metal plate and press-molding, and the cross-sectional shape (the cross-sectional shape shown in FIG. 2) cut along a plane passing through the axis O forms a substantially U-shaped ring. A mounting cylinder part 1a fixed to the crankshaft, a radial direction part 1b extending from the front end to the outer peripheral side, and extending from the outer periphery of the radial direction part 1b to the back side and formed concentrically with the mounting cylindrical part 1a. The rim portion 1c is formed.
[0012]
The dynamic vibration absorbing portion 2 includes a sleeve 21 press-fitted to the outer peripheral surface of the rim portion 1c of the hub 1 with an appropriate tightening margin, an annular mass body 22 disposed concentrically on the outer peripheral side, a sleeve 21 The damper rubber 23 is elastically coupled to the annular mass body 22, and its torsional direction natural frequency is a predetermined frequency region where the torsion angle of the crankshaft is maximum, in other words, the torsional direction natural frequency of the crankshaft. It is tuned to match.
[0013]
The sleeve 21 is manufactured by cutting a metal tube or the like, the annular mass body 22 is manufactured by casting or cutting a thick metal tube, and the damper rubber 23 includes the sleeve 21 and the annular mass body. Between the peripheral surfaces facing 22, the rubber-like elastic material is integrally vulcanized and vulcanized and bonded. That is, the dynamic vibration absorbing portion 2 is formed as a vulcanized molded body of the sleeve 21 and the annular mass body 22 and the damper rubber 23, and then the sleeve 21 is press-fitted into the outer peripheral surface of the rim portion 1 c of the hub 1 to be inserted into the hub 1. It is attached.
[0014]
The coupling portion 3 includes a pulley 31, a coupling rubber 32 that elastically connects the pulley 31 and the hub 1, and a bearing 33 that holds the pulley 31 concentrically with respect to the hub 1.
[0015]
The pulley 31 is manufactured by punching a metal plate and press-molding, and the cross-sectional shape (the cross-sectional shape shown in FIG. 2) cut along a plane passing through the axis O forms a substantially U-shaped ring. A pulley main body 31a extending so as to surround the outer peripheral side of the annular mass body 22 and having a poly V groove 31b formed on the outer peripheral surface, a radial direction portion 31c extending from the back end to the inner peripheral side, and the diameter It has a supported cylinder part 31d that extends from the inner peripheral end of the direction part 31c to the front side and is inserted into the outer periphery of the attachment cylinder part 1a of the hub 1.
[0016]
The coupling rubber 32 is integrally vulcanized and bonded to the outer peripheral surface of the supported cylinder portion 31d of the pulley 31 at the same time as being molded, and is bonded and integrated to the inner peripheral surface of the rim portion 1c of the hub 1 with an adhesive. It is a thing. Further, the coupling rubber 32 has a strength necessary for transmitting torque, and as shown in FIG. 1, at an interval of 90 ° with respect to the circumferential direction centering on the axis O. The gap portions 4 are formed between the coupling rubbers 32, 32,. And by setting it as such a circumferential direction intermittent shape, the shear spring constant with respect to the circumferential direction is set low enough.
[0017]
The bearing 33 is formed in a cylindrical shape from a synthetic resin material having excellent wear resistance such as PTFE and having a low friction coefficient. The bearing 33 has an outer peripheral surface of the mounting cylinder portion 1 a in the hub 1 and a supported cylinder in the pulley 31. The hub 1 and the pulley 31 are disposed concentrically with each other so as to be relatively rotatable.
[0018]
In the gaps 4, 4,... Between the coupling rubbers 32, 32,... In the coupling part 3, rod-like stoppers 5 are respectively arranged, and one ends of the stoppers 5 are respectively appropriate, for example, pins or screws. It is fixed to the radial portion 1b of the hub 1 by the fixing means 5a. The gap 4 is larger than the stopper 5, and a predetermined clearance 4 a due to the gap 4 exists between each stopper 5 and each coupling rubber 32 on both sides in the circumferential direction.
[0019]
The size of the clearance 4a is appropriately set in consideration of the maximum value of the circumferential relative displacement amount between the hub 1 and the pulley 31 that is allowed from the strength of the coupling rubbers 32, 32,. In the state in which no fluctuation is input, the sizes are equal to each other on both sides of each stopper 5. Accordingly, each stopper 5 comes into contact with each coupling rubber 32 when the circumferential relative displacement between the hub 1 and the pulley 31 reaches a predetermined magnitude, and the circumferential relative displacement with respect to the pulley 31 is reduced. The coupling rubber 32 is limited to prevent excessive torsional deformation.
[0020]
In the assembly of the torque fluctuation absorbing damper of this embodiment, first, the damper rubber 23 is integrally vulcanized and vulcanized and bonded with a rubber-like elastic material between the opposed peripheral surfaces of the sleeve 21 and the annular mass body 22; A coupling rubber 32 is integrally vulcanized and bonded to the outer peripheral surface of the supported cylindrical portion 31d of the pulley 31 with a rubber-like elastic material, and a bearing 33 is attached to the outer peripheral surface of the mounting cylindrical portion 1a of the hub 1. The stopper 5 is attached to the radial portion 1b of the hub 1 while extrapolating. Then, the dynamic vibration absorbing portion 2 that is a vulcanized molded body of the sleeve 21 and the annular mass body 22 and the damper rubber 23 is attached to the hub 1 by press-fitting the sleeve 21 into the outer peripheral surface of the rim portion 1c of the hub 1, In addition, an adhesive is applied in advance to the outer peripheral end portion of each coupling rubber 32 and / or the inner peripheral surface of the rim portion 1c of the hub 1, so that each gap portion 4 and each stopper 5 between the coupling rubbers 32, 32,. .. Are inserted between the rim portion 1c of the hub 1 and the bearing 33. The supported cylindrical portion 31d of the pulley 31 and the coupling rubbers 32, 32,.
[0021]
An appropriate tightening allowance is set between the sleeve 21 and the rim portion 1c of the hub 1 in the dynamic vibration absorbing portion 2, so that the damper rubber 23 is slightly compressed in the radial direction in the press-fitting process, Thereby, the tensile stress in the radial direction caused by the shrinkage after the molding on the damper rubber 23 between the sleeve 21 and the annular mass body 22 is effectively eliminated or reduced. Further, an appropriate tightening allowance can also be set between the coupling rubber 32 and the rim portion 1 c of the hub 1.
[0022]
The torque fluctuation absorbing damper according to this embodiment is rotated together with the crankshaft by attaching the hub 1 to the shaft end of the crankshaft of the internal combustion engine. The torque of the crankshaft is transmitted from the rim portion 1 c of the hub 1 to the pulley 31 via the coupling rubber 32. A V-belt (not shown) for transmitting drive torque is wound around the rotation shaft of the auxiliary device around the poly V groove 31b formed on the outer peripheral surface of the pulley body 31a of the pulley 31.
[0023]
The internal combustion engine is driven while repeating the steps of intake, compression, explosion (expansion) and exhaust, and the reciprocating motion of the piston is converted into the rotational motion of the crankshaft. Along with this, periodic torque fluctuations are generated, but these torque fluctuations are effectively absorbed by the shear deformation operation of the coupling rubber 32 in the coupling part 3, so that the torque transmitted to the V-belt is smoothed. Further, in the frequency range where the torsional angle due to the torsional vibration of the crankshaft is maximum, the secondary vibration system composed of the annular mass body 22 and the damper rubber 23 in the dynamic vibration absorber 2 resonates in the circumferential direction, and the torque due to the resonance is Since the torque and direction of the input vibration are reversed, the peak of the crankshaft torsion angle can be effectively reduced.
[0024]
Since the coupling rubber 32 has an intermittent shape in the circumferential direction, the shear spring constant in the circumferential direction is sufficiently low as compared to the conventional continuous one in the circumferential direction. Yes. For this reason, it exhibits a superior torque fluctuation absorbing function by undergoing large shear deformation with respect to the input of torque fluctuation and converting it as heat energy due to internal friction.
[0025]
By the input of torque fluctuation, the hub 1 and the pulley 31 are relatively displaced in the circumferential direction with sliding with the bearing 33 and deformation of the coupling rubber 32, and the displacement amount (amplitude) depends on the torque fluctuation width. Increase. Further, the vibration system constituted by the coupling rubber 32 and the pulley 31 has a torsional direction resonance region in a low frequency region as compared with the dynamic vibration absorber 2, so that the hub 1 can also be resonated in the low speed rotation region. And the circumferential relative displacement amount of the pulley 31 increases. When the amplitude of each piece reaches the size of the circumferential clearance 4a between each coupling rubber 32 and each stopper 5, the stopper 5 and the coupling rubber 32 come into contact with each other, so that the hub 1 and the pulley 31 are in the circumferential direction. Since the relative displacement is limited, it is possible to prevent the coupling rubber 32 from undergoing excessive torsional deformation.
[0026]
Since the stopper 5 is in contact with the coupling rubber 32, an irritating contact sound is not generated. Moreover, since the coupling rubber 32 is deformed at the contact portion when contacting the stopper 5, the circumferential direction of the hub 1 and the pulley 31 due to a certain torque fluctuation even after the stopper 5 and the coupling rubber 32 contact each other. Relative displacement is allowed. For this reason, the circumferential displacement of the hub 1 and the pulley 31 is restrained in a buffering manner by the contact between the stopper 5 and the coupling rubber 32.
[0027]
Further, the pulley 31 has a shape in which the radial direction portion 31c covers the entire coupling rubber 32 and the dynamic vibration absorbing portion 2 from the back side, so that the coupling rubber 32 and the damper rubber 23 from the internal combustion engine existing on the back side. The radiant heat is effectively cut off. Therefore, deterioration of the coupling rubber 32 and the damper rubber 23 due to heat can be prevented, and excellent performance can be exhibited over a long period of time.
[0028]
The present invention is not limited to the embodiment described above. For example, although the stopper 5 is attached to the hub 1 in the illustrated embodiment, the object of the present invention can be realized even if it is attached to the pulley 31. The number of the stopper 5 and the coupling rubber 32 (gap portion 4) The size and size are also arbitrarily set according to the use conditions. In the above-described embodiment, the torque is transmitted from the hub 1 to the pulley 31. However, in the present invention, the driving torque input from the outside to the pulley 31 via the belt is used as the hub 1. It can also be applied as torque fluctuation absorbing means in the case of transmission to the rotating shaft via
[0029]
In the illustrated embodiment, the gap portion 4 is formed between the coupling rubbers 32, 32,... Formed intermittently in the circumferential direction. The portion 4 may be formed in the coupling rubber 32 in a hole shape (window shape) or a non-penetrating blind hole shape.
[0030]
【The invention's effect】
As described above, according to the torque fluctuation absorbing damper according to the present invention, since the coupling rubber has the gap, it is possible to obtain a superior torque fluctuation absorbing performance by reducing the spring constant in the circumferential direction.
[0031]
In addition, since the increase in the deformation amount of the coupling rubber due to the increase in the circumferential relative displacement amount of the hub and the pulley is limited by the contact between the coupling rubber and the stopper disposed in the gap, an irritating contact sound is generated. In addition, due to the deformation of the coupling rubber due to contact with the stopper, the torque fluctuation is absorbed even after the contact between the stopper and the coupling rubber, and the circumferential relative displacement between the hub and the pulley is buffered. Can be stopped.
[Brief description of the drawings]
FIG. 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 orthogonal to an axis O thereof.
2 is a cross-sectional view taken along line II-O-II ′ in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Hub 1a Attachment cylinder part 1b Radial part 1c Rim part 2 Dynamic vibration-absorbing part 21 Sleeve 22 Annular mass 23 Damper rubber 3 Coupling part 31 Pulley 31a Pulley main body 31b Poly-V groove 31c Radial part 31d Supported cylinder part 32 Cup Ring rubber 33 Bearing 4 Gap 4a Clearance 5 Stopper 5a Fixing means

Claims (1)

A hub (1) attached to the rotating shaft and a pulley (31) rotatable relative to the hub (1) are elastically connected via a coupling rubber (32). The ring rubber (32) is provided with a plurality of gaps (4) at a predetermined interval in the circumferential direction, and each of the gaps (4) is spaced from the hub (1) or the pulley (31) at a predetermined interval in the circumferential direction. The coupling rubber (32) is loosely fitted in the circumferential direction with a predetermined clearance (4a) with the stopper (5) provided by the hub (1) and a rim extending from the outer periphery of the hub (1). A part (1c), a radial direction part (31c) of the pulley (31), and an inner peripheral end of the hub (1) on the inner peripheral side of the rim (1c) extending from the inner peripheral end thereof Supported by the cylindrical part (1a) via a bearing (33) It is surrounded by a support cylinder (31d) and is integrally bonded to the inner peripheral surface of the rim (1c) of the hub (1) and the outer peripheral surface of the supported cylinder (31d) of the pulley (31). torque fluctuation absorbing damper, characterized in that those were.

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