JPH0470499B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a dual type dynamic damper pulley. A pulley that transmits rotational driving force to a predetermined subsequent member via a power transmission belt that is wrapped around the surface of the pulley.It absorbs vibrations of the rotating shaft and reduces vibrations and noise in the rotating shaft and engine. The present invention relates to a dual-type damper pulley equipped with a damper mechanism that reduces damping.

(Background Art) In general, when a rotating shaft such as a crankshaft of an internal combustion engine rotates, complex torque fluctuations are caused to the rotating shaft, and as a result, very complex torque fluctuations are caused to the rotating shaft and the engine. Vibration and noise are generated, and further problems such as breakage of the rotating shaft are caused.

Therefore, in the past, in vehicle engines, etc., in addition to attaching a flywheel to the rotating shaft to smooth the torque,
As shown in Utility Model Application Publication No. 56-115050, etc.
By attaching a cylindrical torsional damper having a sub-vibration system (vibration absorber) to the rotating shaft and causing the sub-vibration system to resonate, vibrations and noise in the main vibration system (rotating shaft) are absorbed and reduced. In order to do this, so-called dynamic vibration absorbers have been adopted.

By the way, such a torsional damper is, for example, a cylindrical damper mass that is arranged concentrically on the outside in the radial direction of a hub that has a boss that is fixed to a rotating shaft such as a crankshaft. , a structure in which they are integrally connected by a cylindrical elastic body interposed between them is adopted, and by reducing the resonance amplitude of torsional vibration in the crankshaft etc., such engine noise is reduced. Its purpose is to reduce the

However, the vibrations generated in crankshafts, etc. are mainly a combination of two vibrations: torsion and bending (in the direction perpendicular to the axis), and exhibit various vibration modes depending on the supporting state of the rotating shaft and engine. Therefore, in the conventional vibration suppression mechanism using a torsional damper as described above,
The full effect could not be achieved.

That is, in the case of a rotating shaft equipped with such a torsional damper, deformation in the elastic body is caused by shearing in response to the generated torsional vibration, so that the mass attached to it is It can effectively act as a damper (vibration absorber), but on the other hand, in response to the displacement of the mass corresponding to the bending vibration generated in the rotating shaft, the deformation of the elastic body is due to compression or tension. In addition, the elastic body is required to have a certain spring hardness in order to achieve the desired vibration damping effect against torsional vibration, and its thickness is regulated. The spring characteristics in the direction perpendicular to the axis of the body were set to be stiff, and therefore the mass attached to it could not effectively act as a damper against bending vibrations. In short, the effect of the conventional torsional damper as a vibration absorber could only be effectively exhibited against torsional vibrations in the rotating shaft.

In addition, in recent years, dual dampers with two damper masses have been used as dampers attached to the crankshafts of internal combustion engines. −160437 Publication and JP-A-Sho
It has been proposed in Publication No. 59-40060, etc.

However, in such a dual damper, in addition to the conventional torsional damper structure as described above, an inner space is provided inside the hub,
It is simply an addition of a second damper mass that acts as another vibration absorber against torsional vibrations, and for this reason it will never have an effective vibration absorbing effect as a vibration absorber for crankshafts etc. that involve vibrations in the bending direction. It was not something that could be played.

In this way, conventional vibration absorbers that are attached to a rotating shaft such as a crankshaft to absorb and suppress the vibrations of the rotating shaft are only effective against vibrations in the torsional direction of the rotating shaft. However, it does not contribute to the absorption of vibrations in the bending direction, and therefore, in cases where the vibration has two directions, such as the crankshaft of an internal combustion engine, the torsional direction and the bending direction. However, it has not been possible to effectively reduce the vibration and noise of such rotating shafts and engines.For example, it has not been possible to effectively reduce noise caused by bending vibrations of rotating shafts, such as vehicle noise with a hitting sound generated around 350 Hz. was extremely difficult.

(Problem to be solved) Here, the present invention has been made against the background of the above-mentioned circumstances, and the problem to be solved is to solve the problem by attaching it to a rotating shaft such as a crankshaft of an internal combustion engine. , a pulley having a dual-type dump damper function that can absorb torsional vibration and bending (axis-perpendicular direction) vibration of the rotating shaft and effectively reduce the vibration and noise of the rotating shaft and the engine. It is about providing.

(Solution Means) In order to solve this problem, the present invention is characterized by (a) a boss portion attached to a rotating shaft, a cylindrical portion located on the radially outer side of the boss portion, and a (b) a pulley body having a connecting part that connects a boss part and the cylindrical part; (c) a first elastic body interposed between the cylindrical portion of the pulley body and the first damper mass; (d) ) a cylindrical second damper mass disposed concentrically within the inner space of the cylindrical portion of the pulley body; and (e) an axial end of the second damper mass and the pulley body opposite thereto. The second damper mass is supported by the connecting portion by being interposed between the surfaces facing the connecting portion in the axial direction and directly fixed to the second damper mass and the connecting portion, and a second elastic body that exerts a shearing force against movement of the second damper mass in the radial direction.

(Operations and Effects) That is, in the dual type damper pulley having the structure according to the present invention as described above, the first damper mass provided to the pulley body via the first elastic body, Like the damper mass in a conventional torsional damper, it functions as a sub-vibration system for torsional vibrations generated on a predetermined rotating shaft (main vibration system) to which this damper pulley is attached, and is effective as a dynamic vibration absorber for torsional vibrations. On the other hand, a second damper mass is attached to the pulley body via a second elastic body arranged in such a manner that deformation in response to displacement in the direction perpendicular to the axis generates a shearing force. Therefore, the spring characteristics of the second elastic body in the direction perpendicular to the axis can be set to be sufficiently soft, and therefore the second damper mass can absorb the bending generated in the rotating shaft to which the pulley body is attached. It can effectively function as a sub-vibration system for vibrations (in the axis-perpendicular direction) and as a dynamic vibration absorber for bending vibrations.

Therefore, by attaching such a dual type damper pulley to a rotating shaft such as a crankshaft of an internal combustion engine, vibrations generated in the rotating shaft can be suppressed very easily and effectively. Therefore, the vibration and noise of such an engine can be significantly reduced, and a damper pulley that can exert an effective vibration absorption effect on a rotating shaft that vibrates in the bending direction has never been seen before. be.

Further, in the dual type damper pulley having the structure according to the present invention, the second elastic body that elastically attaches the second damper mass to the connecting portion of the pulley main body connects the second damper mass and the connecting portion. Since the second damper mass is directly fixed to the connecting part, the second damper mass can be advantageously attached to the connecting part without the need for other mounting members and with a small number of parts. Therefore, it also has the effect that the mounting strength and durability of the second damper mass can be advantageously ensured with a simple structure.

Furthermore, in the dual type damper pulley according to the present invention, the second damper mass is directly attached via the second elastic body to the pulley that transmits the rotational force of the rotating shaft to the succeeding member. Therefore, the increase in the rotating mass on the rotating shaft side that constitutes the main vibration system due to the addition of a damper mechanism for bending vibration can be advantageously suppressed, thereby reducing the increase in the rotating mass of the main vibration system. The major advantages are that significant changes in the vibration form such as the amplitude and frequency of bending vibration in the rotating shaft caused by the vibration can be effectively prevented, and tuning in the damper mechanism can be easily performed. It has.

(Example) Hereinafter, in order to clarify the present invention more specifically, an example according to the present invention will be described in detail based on the drawings.

First, FIG. 1 shows a dual-type damper pulley 1 having a structure according to the present invention and also serving as a V-pulley.
0 is shown in longitudinal section.

In this figure, 12 is a pulley body located at the center of the dual type damper pulley 10 and having a substantially cylindrical shape.
Cylindrical first damper masses 22 made of steel are arranged concentrically, and a first elastic member 24 made of rubber is interposed between them to form an integral structure. . On the other hand, the pulley body 12
A second damper mass 26 made of steel and having a cylindrical shape is arranged concentrically in the internal space of the damper mass 26, and a second elastic member 28 made of rubber is attached to the axial end of the second damper mass 26. It is attached to the pulley body 12.

More specifically, the pulley body 12 is a steel pulley that is attached to a crankshaft of a predetermined internal combustion engine (not shown) and rotates therewith, as shown in FIGS. 2 and 3. In order to be attached to a predetermined crankshaft, a keyway 13 as a power transmission part is provided on the inner circumference of the crankshaft.
a small-diameter cylindrical boss portion 14 provided with a cylindrical portion 14; a cylindrical portion 16 concentrically positioned radially outwardly of the boss portion 14 at a predetermined distance apart;
connecting the outer peripheral surface and the inner peripheral surface of the cylindrical portion 16;
The connecting portion 18 extends radially outward in the shape of a flange at the end of the boss portion 14. Note that the connecting portion 18 on the inner circumferential surface of the cylindrical portion 16
is formed at the boss portion 1 in the axial direction.
The inner space of the cylindrical portion 16 is partitioned in the direction perpendicular to the axis by the connecting portion 18, and the inner space on the side where the boss portion 14 is not located is made relatively large. Mass accommodation space 30
is formed. Further, a plurality of (in this embodiment, two each) holding holes 32 and bolt holes 34 are located at the radial center of the connecting portion 18 and penetrate in the axial direction, and are provided at equal intervals in the circumferential direction. There is.

Further, the first damper mass 22 disposed outside the pulley body 12 is
It has a cylindrical shape having approximately the same length as the cylindrical portion 16 of No. 2, and a large number of V grooves 35 are formed on its outer peripheral surface. And, on such an outer peripheral surface,
A predetermined V-belt having a cross-sectional shape corresponding to the V-groove 35 is wound around the dual-type damper pulley 10, thereby forming a V-belt drive that transmits the driving force from the crankshaft to a predetermined subsequent member. It is designed to function as a pulley for use.

Further, as shown in FIG. 6, a first elastic member 24 disposed between the first damper mass 22 and the cylindrical portion 16 of the pulley body 12 is , is formed integrally with a metal sleeve 20 having a thin cylindrical shape having substantially the same length as the pulley main body 12 and arranged concentrically at a predetermined distance inside the pulley main body 12; The metal sleeve 20 is press-fitted and fixed onto the outer circumferential surface of the cylindrical portion 16 of the pulley body 12, so that it is integrally connected to the pulley body 12.

On the other hand, the second damper mass 26 disposed within the mass accommodation space 30 of the pulley body 12 has a cylindrical shape, as shown in FIGS. 4 and 5, and is attached to the pulley body 12. In this state, a through hole 36 extending in the axial direction is formed in a portion of the cylinder wall corresponding to the bolt hole 34 of the connecting portion 18.
is provided.

As shown in FIG. 1, an annular second elastic member 28 is disposed between the axial end of the second damper mass 26 and the connecting portion 18 of the pulley body 12 facing thereto. is provided so that the second damper mass 26 is attached to and supported by the pulley body 12 via the second elastic member 28. A communication hole 38 is provided in the second elastic member 28 at a position corresponding to the through hole 36.
8, the through hole 36 of the second damper mass 26 is communicated with a bolt hole 34 provided in the connecting portion 18 of the pulley body 12, and serves as a service hole for a predetermined member on the back side of the damper.

Furthermore, the through hole 36 of the second damper mass 26
In contrast, each head portion 4 has a length longer than the second damper mass 26 and an outer diameter larger than the inner diameter of the through hole 36.
A fall prevention pin 40 having a diameter of 2 is inserted,
A communication hole 38 formed in the second elastic member 28
The distal end portion thereof is screwed into a bolt hole 34 provided in the connecting portion 18 of the pulley main body 12 to be fixed. Note that the shaft portion of the fall prevention pin 40 and the second damper mass 26
A gap is formed at a predetermined interval between the second damper mass 26 and the through hole 36.
On the other hand, the structure is such that a predetermined amount of displacement in the direction perpendicular to the axis based on the deformation of the second elastic member 28 is allowed.

By the way, when obtaining the dual type damper pulley 10 having such a structure, for example, the following method is suitably adopted.

First, a predetermined rubber material is vulcanized and molded while the first damper mass 22 and the metal sleeve 20 are held concentrically.
A first elastic member 24 is formed and they are vulcanized and bonded to form an integral structure.

On the other hand, the second damper mass 26 is attached to the pulley body 1.
By injecting and vulcanizing a predetermined elastic member through a plurality of holding holes 32 provided in the connecting portion 18 while holding it concentrically in the mass storage space 30 of No. 2, the elastic member is vulcanized. A second elastic member 28 is formed therebetween, and the axial end portion of the second damper mass 26 is vulcanized and bonded to the connecting portion 18 facing the second damper mass 26 .

Next, the obtained integrally vulcanized molded product is press-fitted and fixed to the outer peripheral surface of the cylindrical portion 16 of the pulley main body 12 via the metal sleeve 20. Note that the inner diameter of the metal sleeve 20 is the same as that of the pulley body 1.
The outer diameter of the second cylindrical portion 16 is made smaller by the press-fitting allowance, thereby applying preliminary compression to the first elastic member 16 and making it possible to firmly fix it to the pulley body 12. .

Thereafter, a fall prevention pin 40 is inserted into each of the plurality (two) through holes 36 provided in the second damper mass 26, and the tip thereof is inserted into the connecting portion 18 of the pulley body 12. By screwing and fixing into the bolt holes 34, the desired dual type damper pulley 10 can be obtained.

The dual type damper pulley 10 having such a structure is used by being attached to the crankshaft of a predetermined internal combustion engine at the inner peripheral surface of the boss portion 14 thereof.

Therefore, in the dual type damper pulley 10 having such a structure, the deformation in the first elastic member 24 is caused by shearing in response to the torsional vibration generated in the crankshaft attached to the pulley body 12. Since this vibration is generated, the first damper mass 22 attached thereto can effectively act as a vibration absorber (sub-vibration system) against such vibration. On the other hand, with respect to vibrations in the bending direction (direction perpendicular to the axis) generated in the crankshaft, deformation in the second elastic member 28 is caused by shearing, and therefore, the second elastic member 28 attached to it The damper mass 26 can effectively act as a vibration absorber (sub-vibration system) against such vibrations.

That is, since the complex vibrations generated in the crankshaft are mainly caused by factors in two directions, the torsional direction and the bending direction, by installing the dual type damper pulley 10 as described above, it is possible to Vibrations in the directions of 350, which was impossible with a damper.
It is also possible to extremely effectively suppress vehicle noise that has a hitting sound generated around Hz.

In addition, such dual type damper pulley 1
0, the second damper mass 26, which constitutes a vibration absorber against bending vibration, is connected to the second elastic member 2, with respect to the pulley body 12, which constitutes a pulley that transmits the rotational force of the crankshaft to a succeeding member.
8, it is possible to advantageously suppress an increase in the rotating mass in the main vibration system when providing a vibration absorber for such bending vibrations, and thereby the main vibration system An increase in the amplitude of bending vibration, a change in frequency, etc. caused by an increase in the rotating mass of the bending vibration can be effectively suppressed, and the vibration absorbing effect of the vibration absorber against such bending vibration can be extremely effectively exhibited. This also makes tuning easier.

Furthermore, since the second damper mass 26 is integrally fixed to the pulley body 12 of the second elastic member 28 by directly vulcanizing and adhering it, special special measures are required when installing it. A vibration absorber for bending vibration as described above can be advantageously constructed with a small number of parts and a simple structure without requiring any mounting members.

Furthermore, in the dual-type damper pulley 10 of this embodiment, even if the second elastic member 28 supporting the second damper mass 26 is broken due to deterioration or the like, it can be used as a fail-safe mechanism. The falling-off prevention pin 40 can completely prevent the second damper mass 26 from falling off from the pulley body 12.

Although a preferred embodiment of the present invention has been described above in detail, the present invention is by no means to be construed as being limited only to such specific example.
Without departing from the spirit of the present invention, it is possible to implement the present invention in forms with various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art.
It goes without saying that the present invention includes such embodiments.

For example, the fail-safe mechanism in the embodiment described above was composed of a plurality of fall prevention pins 40 inserted into the through holes 36 of the second damper mass 26, but various other structures may be adopted as appropriate. For example, as shown in FIG. 7, a ring-shaped falling-off prevention metal fitting 44 having an abutting side 47 for the end surface of the cylindrical part 16 of the pulley main body 12 at its outer peripheral portion is attached to the pulley main body 1.
The second damper mass 26 has a gap of a predetermined distance from the axially outer end surface of the second damper mass 26 on the side end surface of the second mass accommodation space 30.
It is also possible to attach and fix the pulley body 12 with a plurality of bolts 46 that are inserted through the through holes 36 and screwed into and fixed to the bolt holes 34 of the pulley body 12.

Moreover, as shown in FIG. 8, the pulley body 1
The flange-like fitting side 48 that is fitted onto the inner circumferential surface of the second cylindrical part 16 connects the annular falling-off prevention metal fitting 50 erected on the outer peripheral part of the second damper mass 26 in the axial direction of the second damper mass 26. The fitting side 48 is fixed by fitting or the like to the inner circumferential surface of the cylindrical portion 16 forming the mass accommodation space 30 with a gap of a predetermined distance from the outer end surface. It is also possible to do so.

Furthermore, in the present invention, such a fail-safe mechanism is not necessarily required;
It is also possible to form a dual-type damper pulley without providing a failsafe mechanism. In addition, in FIG. 7 and FIG. 8, the dual type damper pulley 10 in the above embodiment is shown.
For members having the same structure, the same numbers will be given to the corresponding members, and detailed explanation will be omitted.

Further, the rotating shaft to which the dual type damper pulley according to the present invention is to be attached is not limited to the crankshaft of an internal combustion engine as shown in the above embodiment, but can be applied to various rotating shafts where vibrations are generated. The present invention can be applied to various locations, and thereby the excellent effects described above can be effectively achieved.

Furthermore, in the dual type damper pulley in the above embodiment, the first damper mass 22 is integrally constructed with the metal sleeve 20 via the first elastic member 24, and the metal sleeve 20 is Although the first damper mass 22 is attached by being press-fitted into the outer peripheral surface of the cylindrical portion 16 of the pulley body 12, it is only necessary that the first damper mass 22 is attached to the pulley body 12 via the first elastic member 24. For example, by integrally vulcanizing the first elastic member between the cylindrical part of the pulley body and the metal sleeve, and then press-fitting the first damper mass into the outer peripheral surface of the metal sleeve. Alternatively, the first elastic member may be directly vulcanized and molded between the first damper mass and the outer peripheral surface of the cylindrical portion of the pulley body, and they may be integrally fixed. It is also possible to do so.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a dual-type damper pulley that is an embodiment of the present invention, and corresponds to the - section in FIG. FIG. 3 is a front view of the pulley main body used in the example, FIG. 3 is a cross-sectional view taken in FIG. 2, and FIGS. Fig. 4 is a front view of the damper mass, and Fig. 5 is a diagram showing the - in Fig. 4.
FIG. FIG. 6 is a longitudinal sectional view showing an integrally vulcanized product of the first damper mass, first elastic member, and metal sleeve used in the embodiment shown in FIG. 1. . Furthermore, Figures 7 and 8
Each figure is a longitudinal sectional view corresponding to FIG. 1 showing other embodiments of the dual type damper pulley according to the present invention. 10...Dual type damper pulley, 12
... Pulley main body, 14 ... Boss part, 16 ... Cylindrical part, 18 ... Connection part, 22 ... First damper mass, 24 ... First elastic member, 26 ... Second damper mass, 28... second elastic member, 32...
Through hole, 34... Bolt hole, 36... Pin through hole, 40... Fall prevention pin, 42... Head part,
44, 50... Falling prevention metal fittings.

Claims (1)

[Scope of Claims] 1. A pulley main body having a boss portion attached to a rotating shaft, a cylindrical portion located on the radially outer side of the boss portion, and a connecting portion connecting the boss portion and the cylindrical portion; a cylindrical first damper mass around which a power transmission belt is wound around the outer circumferential surface of the cylindrical first damper mass, which is arranged concentrically at a predetermined distance on the radially outer side of the cylindrical portion of the pulley body; and and a first elastic body interposed between the first damper mass and the first damper mass; a second cylindrical damper mass disposed concentrically within the inner space of the cylindrical portion of the pulley body; It is interposed between the axially opposing surfaces of the axial end of the second damper mass and the connecting portion of the pulley body facing thereto, and is directly fixed to the second damper mass and the connecting portion. a second elastic body that causes the second damper mass to be supported by the connecting portion and exerts a shearing force against movement of the second damper mass in the radial direction. Dual type damper pulley. 2. The dual-type damper pulley according to claim 1, wherein the second elastic body is vulcanized and bonded to the second damper mass and the connecting portion of the pulley body, respectively. 3. The dual-type damper pulley according to claim 1 or 2, wherein the first damper mass is a V-ribbed pulley cylinder having a V-groove on the outer peripheral surface of which a V-belt is stretched. 4 It is inserted into a through hole that axially passes through the cylindrical wall of the second damper mass, and one end is fixed to the connection part of the pulley body, while the other end projects outward from the through hole. 4. A dual-type damper pulley according to any one of claims 1 to 3, comprising a drop-off prevention pin whose protruding portion is a larger head than the through hole. 5. An annular fall-off prevention fitting that faces an axially outer end surface of the second damper mass with a predetermined gap therebetween and that restricts the second damper mass from coming off outward, is attached to the pulley. A dual type damper pulley according to any one of claims 1 to 3, which is fixed to an axial end of a cylindrical portion of the main body.