JP2004108528A - Torque fluctuation absorption damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive torque fluctuation absorption damper which can secure sufficient durability of an elastic member for transmitting torque. <P>SOLUTION: A second elastic member 5 at a coupling section B connects an outward flange 22b of an annular mass object 2 and an inward flange 42c of a pulley 4 to each other in the axial direction. Accordingly, even when the size in the radial direction cannot be set to be large, the sufficient thickness of the second elastic member 5 in the connecting direction can be secured so as to improve the durability or to reduce the size and weight of the whole of the damper. The pulley 4 is provided with a pair of inward flanges 41b, 42c which are arranged side by side in the axial direction. The inward flanges 41b, 42c hold pulley receptacle portions 21b, 21c of the annular mass object 2 from both sides thereof in the axial direction via bearings 6, 7, so that the axial displacement of the pulley 4 is restricted and the pulley 4 becomes stable. Moreover, it is possible to prevent disconnection of the pulley 4 when the second elastic member 5 is damaged by any chance. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a torque fluctuation absorbing damper that transmits torque from a drive shaft of an internal combustion engine or the like to another rotating device and absorbs fluctuations in the torque.
[0002]
[Prior art]
A part of the driving force from the internal combustion engine of the vehicle is applied to an auxiliary machine such as an alternator or a water pump through an endless belt from a pulley provided at the tip of the crankshaft. Therefore, the pulley is provided with a torque fluctuation absorbing damper for absorbing the torque fluctuation and smoothing the transmitted torque.
[0003]
As this kind of torque fluctuation absorbing damper according to the related art, for example, a decoupled damper pulley described in Patent Document 1 is known. That is, the decoupled damper pulley is connected to the outer periphery of a hub member which is attached to the shaft end of the crankshaft and rotates integrally with the pulley member via the first rubber-like elastic member, and is connected to the outer periphery of the hub member. And an inertial mass connected via a second rubber-like elastic member. The secondary vibration system composed of the second rubber-like elastic member and the inertial mass reduces the torsional vibration of the crankshaft by the dynamic vibration absorption effect caused by resonating in the torsional direction in a predetermined frequency range. The drive torque input to the hub member is transmitted to the pulley member while absorbing the torque fluctuation by the torsional shearing action of the first rubber-like elastic member.
[0004]
[Patent Document 1]
Utility Model Registration No. 2605662 (FIG. 1, 0006 to 0009)
[0005]
[Problems to be solved by the invention]
Here, according to the conventional torque fluctuation absorbing damper, due to the circumferential relative displacement between the hub member and the pulley member, the strain received by the first rubber-like elastic member connecting the hub member and the pulley member is ,
Strain% = {(outer radius x twist angle) / radial thickness} x 100
It becomes. Therefore, when the torsion angle between the hub member and the pulley member is the same, the larger the first rubber-like elastic member is in the radial direction (thickness in the connection direction) and the smaller the outer radius is, the first rubber-like elastic member becomes. Since the strain applied to the elastic member increases, the radial thickness of the first elastic member needs to be sufficiently large in order to ensure durability. However, since the first rubber-like elastic member is regulated by the radial dimension of the pulley member, the degree of freedom of the dimension is small. Moreover, when the thickness of the first rubber-like elastic member is increased in the radial direction, there is a problem in that the distortion becomes larger toward the outer diameter side with respect to the relative displacement of the hub member and the pulley member in the circumferential direction.
[0006]
In addition, the inertial mass is mainly made of FC material, but requires a large wall thickness in order to achieve a required dynamic vibration absorbing effect by resonance, and therefore has a large radial dimension, which is a rubber-like elasticity. This contributed to the dimensional restriction of the members.
[0007]
In addition, a vulcanized molded body in which a first rubber-like elastic member is vulcanized and bonded between a sleeve and a pulley member which are press-fitted into a hub member, and a second rubber-like elastic member is provided between the hub member and an inertial mass. Two vulcanized moldings, one of the vulcanized molded bodies bonded with sulfur, are required, and the production cost is high.
[0008]
The present invention has been made in view of the above-described problems, and a technical problem of the present invention is that it is possible to ensure sufficient durability of an elastic body that transmits torque even when a radial dimension is restricted. Another object of the present invention is to provide an inexpensive torque fluctuation absorbing damper.
[0009]
[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 elastically couples an annular mass body to an outer periphery of a hub attached to a rotating shaft via a first elastic body. A dynamic vibration absorber connected to the annular mass, a coupling portion elastically connected via a second elastic body to the pulley and the annular mass supported rotatably by the annular mass, and the annular The mass body has a pulley receiving portion and an outward flange portion, the pulley has a pair of inward flange portions arranged in the axial direction with respect to each other, and the second elastic body has one outward direction of the annular mass body. A pulley receiving portion of the annular mass body is provided between a flange portion and one inward flange portion of the pulley axially opposed to the flange portion. It is sandwiched between bearings.
[0010]
In the torque fluctuation absorbing damper according to the second aspect of the present invention, in the configuration according to the first aspect, a part of the pulley receiving part and a part of the inward flange part of the pulley have a predetermined clearance in a circumferential direction. In this state, they are loosely fitted to each other.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a cross-sectional view showing a preferred embodiment of a torque fluctuation absorbing damper according to the present invention, cut along a plane passing through its axis. The “front side” used in the following description is the left side in FIG. 1, that is, the front side of the vehicle, and the “rear side” is the right side in FIG. 1, that is, the internal combustion engine (not shown). It is the side that exists.
[0012]
As shown in FIG. 1, a torque fluctuation absorbing damper according to the present embodiment includes a hub 1 attached to a shaft end of a crankshaft of an internal combustion engine, a dynamic vibration absorbing portion A and a cup provided on the outer peripheral side of the hub 1. And a ring portion B.
[0013]
The hub 1 is made of a metal material and includes a boss 1a externally fixed to a crankshaft, and a cylindrical portion 1b extending from the outer peripheral portion to the front side.
[0014]
The dynamic vibration absorbing portion A is provided between an annular mass 2 disposed concentrically on the outer peripheral side of the cylindrical portion 1b of the hub 1 and an inner peripheral surface of the annular mass 2 and an outer peripheral surface of the cylindrical portion 1b. The first elastic body 3 elastically connects the hub 1 and the annular mass body 2 by press-fitting. The torsional natural frequency of the first elastic body 3 is determined by the circumferential inertial mass of the annular mass body 2 and the first elastic body 3. The elastic body 3 is tuned by the torsional shearing spring constant so as to match the predetermined frequency range in which the torsion angle of the crankshaft is maximized, in other words, the natural frequency of the crankshaft in the torsional direction.
[0015]
The annular mass body 2 in the dynamic vibration absorber A includes an inner mass body 21 and an outer mass body 22 manufactured by press-molding a metal plate having an appropriate thickness. Among these, the inner mass body 21 includes an inner sleeve 21a whose inner peripheral surface is fitted to the outer periphery of the first elastic body 3, a disk-shaped pulley receiving portion 21b that is developed from the rear end to the outer peripheral side, and And a cylindrical pulley receiving portion 21c whose outer peripheral portion is bent toward the front side. Further, the outer mass body 22 has an outer sleeve 22a press-fitted on the outer peripheral surface of the inner sleeve 21a of the inner mass body 21, and an outward flange portion 22b expanded from the front end to the outer peripheral side. .
[0016]
The first elastic body 3 in the dynamic vibration absorbing portion A is annularly vulcanized and molded from a rubber-like elastic material having excellent heat resistance, cold resistance and mechanical strength, and then is formed on the cylindrical portion 1b of the hub 1 and its outer periphery. The annular mass body 2 is press-fitted from one side in the axial direction to the inner sleeve 21a of the inner mass body 21 of the arranged annular mass body 2 and fitted with a required radial interference. When the first elastic body 3 is press-fitted, the outer peripheral surface of the cylindrical portion 1b of the hub 1 and the inner peripheral surface of the inner sleeve 21a of the inner mass body 21 of the annular mass body 2 or the inner peripheral surface of the first elastic body 3 It is preferable to apply a coupling agent for increasing the sliding torque to the peripheral surface and the outer peripheral surface.
[0017]
The coupling portion B includes a pulley 4, a second elastic body 5 elastically connecting the pulley 4 to the annular mass body 2, and a pair of members for supporting the pulley 4 so as to be relatively rotatable with respect to the annular mass body 2. Bearings 6 and 7.
[0018]
The pulley 4 in the coupling portion B is made of a metal material, has a poly-V groove 41a formed on the outer peripheral surface, and has a first inward flange portion 41b extending from the rear end to the inner peripheral side. And an inner peripheral ring 42 manufactured by press-forming a metal plate and fixed to the pulley body 41. The inner peripheral ring 42 includes a press-fit portion 42 a press-fitted on the inner peripheral surface of the pulley body 41 near the front, a bearing holding portion 42 b formed in a stepped shape at an end on the rear side, and a rear surface thereof. A second inward flange portion 42c extending from the end on the inner side to the inner peripheral side, a first inward flange portion 41b on the pulley body 41, and a second inward flange portion 42c on the inner peripheral ring 42. Are axially aligned with each other.
[0019]
The disk-shaped pulley receiving portion 21b of the inner mass body 21 of the annular mass body 2 is located between the two inward flange portions 41b and 42c of the pulley 4, and the cylindrical pulley of the inner mass body 21 is provided. The receiving portion 21c is located between the inner peripheral surface of the pulley main body 41 and the bearing holding portion 42b of the inner peripheral ring 42.
[0020]
The bearings 6 and 7 are formed of a synthetic resin material having a low friction coefficient such as PTFE having excellent wear resistance. One of the bearings 6 includes a bearing holding groove 21 d formed on the back surface of the pulley receiving portion 21 b of the inner mass body 21 of the annular mass body 2, and a first inward flange portion 41 b of the pulley body 41 of the pulley 4. And is interposed between them. Further, the other bearing 7 is provided between the cylindrical outer peripheral surface of the bearing holding portion 42 b of the inner peripheral ring 42 of the pulley 4 and the inner peripheral surface of the cylindrical pulley receiving portion 21 c of the inner mass body 21 of the annular mass body 2. The interposed cylindrical main body portion 7a, bent from the front end to the outer peripheral side, between the radially rising surface of the bearing holding portion 42b and the tip of the cylindrical pulley receiving portion 21c. It has an L-shaped cross section including the interposed thrust receiving portion 7b.
[0021]
Accordingly, the pulley 4 is supported by the annular mass body 2 via the bearings 6 and 7 so as to be rotatable relative to each other, and the bearing interposed between the cylindrical pulley receiving portion 21c and the cylindrical outer peripheral surface of the bearing holding portion 42b. 7, the relative displacement in the radial direction is regulated, and the bearing 6 interposed between the pulley receiving portion 21b and the first inward flange portion 41b, and the pulley receiving portion 21c and the bearing holding portion 42b. A relative displacement in the axial direction is restricted by the thrust receiving portion 7b of the bearing 7 interposed between the radial rising surfaces.
[0022]
The second elastic body 5 in the coupling portion B is made of a rubber-like elastic material having excellent heat resistance, cold resistance and mechanical strength, and one end of the second elastic body 5 is formed on the outer mass body 22 of the annular mass body 2. The other end is integrally vulcanized and bonded to the direction flange 22b, and the other end is integrally vulcanized and bonded to the second inward flange 42c of the inner peripheral ring 42 of the pulley 4. That is, the outer mass body 22, the second elastic body 5, and the inner peripheral ring 42 are manufactured as a vulcanized molded body integrated in advance, and the outer sleeve 22a of the outer mass body 22 is connected to the inner sleeve 21a of the inner mass body 21. The press-fitting portion 42a of the inner ring 42 is press-fitted into the pulley main body 41 while being press-fitted. The outward flange portion 22b and the second inward flange portion 42c are axially opposed to each other, and therefore, the second elastic body 5 extends substantially axially in a cylindrical shape.
[0023]
An annular space S opened to the front is formed between the outer peripheral surface of the second elastic body 5 and the pulley 4, that is, the second elastic body 5 is surrounded by the pulley 4 and the annular mass 2. It is located near the inner circumference in a closed space. In addition, the second elastic body 5 has a required thickness in the radial direction, so that the strength required for transmitting torque is secured, and the outward flange portion 22b and the second inward flange portion 42c are provided. In the dynamic vibration absorbing section A, the spring constant in the torsional direction is sufficiently lower than that of the first elastic body 3 in the dynamic vibration absorber A by having a required thickness in the connecting direction (axial direction).
[0024]
In the pulley receiving portion 21b of the inner mass body 21 of the annular mass body 2, stoppers 21e projecting rearward are formed at regular intervals in the circumferential direction, and are respectively formed in a first inward direction in the pulley body 41 of the pulley 4. It is loosely fitted with a required clearance in the circumferential direction into an engaging hole 41c formed in the flange portion 41b and extending in an arc shape centered on the axis. That is, the stopper 21e interferes with the circumferential end of the engaging hole 41c, thereby limiting the relative displacement of the pulley 4 with respect to the annular mass 2 in the circumferential direction, and excessively twisting the second elastic body 5. This is to prevent deformation.
[0025]
The torque fluctuation absorbing damper of the present embodiment having the above-described configuration is rotated together with the crankshaft by mounting the hub 1 on the shaft end of the crankshaft of the internal combustion engine. The torque of the crankshaft is transmitted from the hub 1 to the pulley main body 41 via the first elastic body 3, the annular mass body 2, the second elastic body 5, and the inner peripheral ring 42. The power is transmitted to a rotating shaft of an auxiliary machine such as a cooling fan or an alternator via a V-belt (not shown) wound around 41a.
[0026]
A load in a direction perpendicular to the axis is applied to the pulley 4 by the tension of the V-belt, but the bearing holding portion 42 b of the inner peripheral ring 42 of the pulley 4 and the cylindrical shape of the inner mass 21 of the annular mass 2 are formed. Since the main body portion 7a of the bearing 7 is interposed between the pulley receiving portions 21c and furthermore, the first elastic body 3 supporting the annular mass body 2 on the outer periphery of the hub 1 has high rigidity against radial compression. 4 is prevented. The axial behavior of the pulley 4 is determined by the bearing 6 and the inner peripheral ring interposed between the disk-shaped pulley receiving portion 21b of the annular mass body 2 and the first inward flange 41b of the pulley body 41. The thrust receiving portion 7b of the bearing 7 is interposed between the radially rising surface of the bearing holding portion 42b and the tip of the cylindrical pulley receiving portion 21c of the annular mass body 2. For this reason, the pulley 4 is stably supported in both the radial direction and the axial direction.
[0027]
The internal combustion engine is driven while repeating the steps of intake, compression, explosion (expansion), and exhaust, and converts the reciprocating motion of the piston into the rotational motion of the crankshaft. The torque fluctuation is converted into heat energy by the second elastic body 5 in the coupling portion B being sheared in a torsion direction by a low spring, and is converted into thermal energy. Is smoothed. On the other hand, the dynamic vibration absorber A composed of the annular mass body 2 and the first elastic body 3 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 Since the direction of the torque is opposite to the direction of the input vibration, the peak of the torsion angle of the crankshaft can be effectively reduced.
[0028]
The second elastic body 5 and the pulley 4 constitute a kind of vibration system. However, this vibration system has a sufficiently low torsional resonance region in the low frequency region as compared with the dynamic vibration absorbing portion A. Also, torque fluctuations caused by the resonance of the dynamic vibration absorber A itself are absorbed by the flexible deformation of the second elastic body 5 and are not transmitted to the pulley 4.
[0029]
When the hub 1 and the annular mass 2 and the pulley 4 are relatively displaced in the circumferential direction due to the input of the torque fluctuation, the second elastic bodies 5 in the coupling portion B become outside the annular mass 2 that are substantially axially opposed to each other. Between the outward flange portion 22b of the mass body 22 and the second inward flange portion 42c of the inner peripheral ring 42 of the pulley 4, shear deformation in the torsional direction occurs. For this reason, when the torsion angle between the annular mass body 2 and the pulley 4 is the same, the distortion of the second elastic body 5 which is received is caused by the thickness in the connecting direction between the outward flange portion 22b and the second inward flange portion 42c. As the thickness, that is, the thickness in the axial direction becomes larger, the second elastic body 5 does not need to have a large radial dimension in order to secure the durability of the second elastic body 5 as in the related art. Therefore, even if the radial size of the torque fluctuation absorbing damper cannot be increased due to restrictions on the outer diameter dimension of the pulley body 41, the shaft between the outward flange portion 22b and the second inward flange portion 42c is not required. By taking a sufficient distance in the direction, excellent durability of the second elastic body 5 can be secured.
[0030]
In other words, since it is not necessary to increase the radial dimension of the second elastic body 5, the outer diameter of the hub 1 can be reduced, and the outer diameters of the annular mass body 2 and the pulley 4 can also be reduced. The size and weight can be reduced. Further, since the annular mass body 2 is constituted by a combination of the inner mass body 21 and the outer mass body 22, which are press-formed products of a metal plate, the annular mass body 2 can be manufactured at low cost, and the pulley receiving portions 21b and 21c which are deployed to the outer peripheral side and the outer mass body 21 Providing the direction flange portion 22b ensures a required inertial mass for dynamic vibration absorption.
[0031]
The second elastic body 5 absorbs the input torque fluctuation by converting it into heat energy, that is, generates heat due to internal friction due to repeated shear deformation. The elastic body 5 is efficiently cooled by the air flowing from the front side to the space S on the outer periphery thereof. Further, the heat generated by the friction with the V-belt in the pulley body 41 is also radiated to the space S, so that the heat is not easily transmitted to the second elastic body 5. Therefore, deterioration of the second elastic body 5 due to heat is effectively prevented.
[0032]
As described above, the second elastic body 5 has sufficient durability, is prevented from being deteriorated by heat, and is excessively twisted by the stopper 21e and the engagement hole 41c. Deformation is prevented, but if the second elastic body 5 is still damaged for some reason, the first inward flange 41b of the pulley 4 and the second inward flange 42c Since the pulley receiving portions 21b and 21c of the annular mass body 2 are interposed therebetween, the pulley 4 does not fall off. Moreover, in such a case, the stopper 21e and the engagement hole 41c are engaged with each other in the circumferential direction, and the engagement state is ensured by the fact that the axial behavior of the annular mass body 2 and the pulley 4 is regulated. Since the driving torque is held, the transmission of the driving torque from the annular mass body 2 to the pulley 4 is continuously performed, and it is possible to avoid a situation in which the internal combustion engine is stopped due to torque interruption to the auxiliary machine.
[0033]
Further, according to the structure of the present embodiment, the vulcanized molded body in which the outer mass body 22, the second elastic body 5, and the inner peripheral ring 42 are integrated is press-fitted between the inner mass body 21 and the pulley body 41, Since the first elastic body 3 is assembled by press-fitting between the hub 1 and the inner mass body 21, there is only one integrally molded product of metal and rubber, and the stopper 21 e is also formed by press-forming the inner mass body 21. Since they are integrally formed, the manufacturing cost can be reduced.
[0034]
【The invention's effect】
As described above, according to the torque fluctuation absorbing damper according to the first aspect of the present invention, the second elastic body in the coupling portion is formed by connecting the annular mass body and the pulley in the axial direction. Even if it is not possible to increase the radial size of the torque fluctuation absorbing damper due to restrictions or the like, it is necessary to secure a sufficient axial thickness of the second elastic body and improve the durability of the second elastic body. Alternatively, the size and weight of the entire damper can be reduced. In addition, a pair of inward flanges provided on the pulley and arranged in the axial direction mutually sandwich the pulley receiving portion of the annular mass body from both sides in the axial direction via bearings, so that the axial behavior of the pulley is restricted from both sides. As a result, the pulley can be reliably prevented from falling off when the second elastic body is broken.
[0035]
According to the torque fluctuation absorbing damper according to the second aspect of the invention, even if the second elastic body is damaged, the annular mass and the pulley are engaged in the circumferential direction, and the pulley receiving portion of the annular mass is connected to the pulley. By being sandwiched between the pair of inward flanges, the engagement state is reliably maintained, so that the transmission of the driving torque to the pulley can be continued.
[Brief description of the drawings]
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.
[Explanation of symbols]
Reference Signs List 1 hub 1a boss 1b cylindrical portion 2 annular mass 21 inner mass 21a inner sleeve 21b, 21c pulley receiving portion 21d bearing holding groove 21e stopper 22 outer mass 22a outer sleeve 22b outward flange 3 first elastic body 4 pulley 41 Pulley body 41a Poly-V groove 41b First inward flange 41c Engagement hole 42 Inner peripheral ring 42a Press-fit part 42b Bearing holding part 42c Second inward flange 5 Second elastic body 6, 7 Bearing 7a Main body 7b Thrust receiving part A Dynamic vibration absorbing part B Coupling part S Space

Claims (2)

A dynamic vibration absorber (A) in which an annular mass body (2) is elastically connected to an outer periphery of a hub (1) attached to a rotating shaft via a first elastic body (3), and the annular mass body (2). A coupling portion (B) in which a pulley (4) supported to be relatively rotatable and the annular mass body (2) are elastically connected via a second elastic body (5); The body (2) has a pulley receiving portion (21b, 21c) and an outward flange portion (22b), and the pulley (4) includes a pair of inward flange portions (41b, 42c) arranged in the axial direction. The second elastic body (5) has one outward flange (22b) of the annular mass body (2) and one inward flange (2) of the pulley (4) axially opposed thereto. 42c), and the pulley receiving portions (21b, 21c) of the annular mass body (2) are Torque fluctuation absorbing damper, characterized in that sandwiched by a bearing (6, 7) from axially opposite sides facing inward flange portion of the pair (41b, 42c). A part of the pulley receiving part (21b) and a part of the inward flange part (41b) of the pulley (4) are loosely fitted to each other in a state where a predetermined clearance exists in the circumferential direction. The torque fluctuation absorbing damper according to claim 1.

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