JPH034052A - Damper pulley sealed with viscous fluid - Google Patents

Abstract

PURPOSE:To improve vibro-isolating effect by providing an annular recessed part in the interior of a pulley main unit, forming a closed mass housing chamber in this recessed part, arranging a mass member in the chamber and supporting this mass member to the pulley main unit with a rubber elastic unit further filling the mass housing chamber with high viscous material. CONSTITUTION:An annular recessed part 22 is concentrically formed with a pulley main unit 12 in the interior of a cylinder part 20 in the pulley main unit 12. This annular recessed part 22 is closed by a cover metal fixture 24, thus a mass housing chamber 34 in a liquid-tight condition is partitioned. A circular annular damper mass 36 is concentrically formed in an extending direction of inner and outer fitting parts 28, 30 of this metal fixture 24 and elastically supported to the cover metal fixture 24 by a rubber elastic unit 38, thus a damper mechanism 44 is constituted. Further the mass housing chamber 34 is sealed inside with high viscous fluid, and a part between the damper mass 36 and an internal surface of the mass housing chamber 34 is filled with the fluid. In the damper mechanism 44 as described in the above, damping force is displayed by shearing force of the rubber elastic unit 38 and the high viscous material.

Description

Detailed Description of the Invention (Technical Field) The present invention includes a dynamic vibration absorber (damper mechanism) and is attached to a rotating shaft such as a crankshaft of an internal combustion engine, thereby absorbing and reducing vibrations in the rotating shaft. The present invention relates to a damper pulley, in particular a damper pulley filled with viscous fluid, in which the damping rate in the damper mechanism can be set sufficiently large, thereby making it possible to easily and advantageously tune the vibration damping characteristics of the damper mechanism. be.

(Background Art) When the crankshaft of an internal combustion engine rotates, complex vibrations and noise are generated in the crankshaft and the engine due to torque fluctuations, etc., and further problems such as breakage of the crankshaft occur. may be triggered.

Therefore, conventionally, in order to reduce vibrations in the crankshaft of vehicle engines, etc., efforts have been made to
As shown in Japanese Utility Model Publication No. 62-69646, etc., an annular mass member is disposed concentrically with respect to a pulley body that is attached to a crankshaft and rotated integrally. A so-called damper pulley, which is equipped with a damper mechanism that is elastically supported by a rubber elastic body interposed between the facing surfaces of the mass member and the pulley main body, has been suitably used.

By the way, in order to effectively obtain the damping effect of such a damper, it is important to tune the mass, spring constant, and damping coefficient of the damper mechanism, and these tuning methods are well known. Thus, -a is carried out according to the fixed point theory in the optimal design method for dynamic dampers.

More specifically, in a mechanical model, the crankshaft that is the subject of vibration damping and equipped with such a damper pulley is represented as a two-degree-of-freedom system in which the crankshaft itself is the main vibration system and the damper mechanism is the secondary vibration system. Since the amplitude magnification curve always passes through two fixed points regardless of the damping rate of the sub-oscillation system, the values of the two fixed points should be made equal, and the maximum value of the amplitude multiplication curve should be set near those fixed points. By making it so that Therefore, when tuning such a damper mechanism, first set the mass mass and spring constant (optimal amount UR) so that the heights of the two fixed points are approximately equal, and then This is done by setting the attenuation coefficient (optimal attenuation) so that the amplitude multiplier becomes approximately the maximum value.

However, in the damper mechanism of the conventional structure as described above, the spring constant and damping coefficient are both set by the elasticity and damping of the rubber elastic body, so it is difficult to obtain sufficient damping force. Therefore, it is difficult to set a damping coefficient that provides optimal damping while securing a spring constant that provides optimal tuning, and therefore there is an inherent problem that it may not be possible to obtain an effective vibration suppression effect. It is.

In addition, in such a damper mechanism, it is difficult to set a sufficient damping coefficient, so the amount of deformation of the elastic member may become excessive during resonance, and therefore sufficient durability may not be obtained. It also had the disadvantage of being difficult to use.

(Solution Section B) Here, the present invention has been made against the background of the above-mentioned circumstances, and the problems to be solved are:
To provide a viscous fluid-filled damper boar that can exhibit an excellent vibration damping effect by setting the damping coefficient of a damper mechanism sufficiently large and tuning it easily and advantageously. be.

(Solution Means) In order to solve this problem, the present invention includes a boss portion attached to a predetermined rotating shaft, and a boss portion located on the radially outer side of the boss portion and integrally connected A pulley body having a cylindrical part and rotated together with the rotating shaft is provided with an annular recess inside the cylindrical part that opens at one end in the axial direction and extends continuously in the circumferential direction, By fitting a lid body into the opening of the recess and closing the opening, a closed mass storage chamber is formed within the recess, and an annular mass member is accommodated and arranged within the mass storage chamber. By elastically supporting the mass member on the pulley body with a rubber elastic body interposed between the mass member and the inner surface of the mass storage chamber, a damper mechanism is constructed, and the inside of the mass storage chamber is The present invention is characterized by a viscous fluid-filled damper pulley filled with a highly viscous fluid.

(Examples) Hereinafter, in order to clarify the present invention more specifically, examples of the present invention will be described in detail with reference to the drawings.

First, FIGS. 1 and 2 each show a damper pulley 10 which is constructed in accordance with the present invention and which also serves as a multi-pulley. In these figures, reference numeral 12 denotes a steel pulley body, and as shown in FIG. A cylindrical portion 20 having a large diameter cylindrical shape and having a plurality of continuous grooves 18 extending in the circumferential direction on the outer circumferential surface of the boss portion 16 is integrated. It has a structure that is formed horizontally and concentrically.

In the pulley main body 12, the boss portion 16 is attached to the crankshaft of a predetermined internal combustion engine (not shown) and rotated integrally with the crankshaft, while the groove provided in the cylindrical portion 20 By wrapping a predetermined belt (not shown) around the crankshaft 18, it is used as a belt drive pulley that transmits the driving force from the crankshaft to a predetermined subsequent member.

The cylindrical portion 20 of such a pulley body 12 is thickened at one end in the axial direction, and inside the thickened portion is opened at one end surface in the axial direction and is opened in the circumferential direction. An annular recess 22 extending continuously from the pulley body 12 is formed concentrically with the pulley body 12 .

As shown in FIGS. 1 and 2, a front metal fitting 24 is fitted into the opening of this annular recess 22. The opening is blocked. Here, as shown in FIG. 4, the front metal fitting 24 has inner fittings each extending in a cylindrical shape toward one side in the axial direction at the inner and outer peripheral edges of the lid part 26 exhibiting an annular plate shape. The joint portion 28 and the outer fitting portion 30 are integrally bent. The inner fitting part 28 and the outer fitting part 30 are press-fitted into the inner and outer circumferential surfaces of the opening of the annular recess 22 provided in the pulley main body 12, respectively. It is fitted into the opening at 22. In addition,
The inner and outer circumferential surfaces of the annular recess 22 on the opening side are respectively enlarged in diameter by a predetermined dimension, and the stepped surface 32
．． By abutting against 32, the enlarged end of the front metal fitting 24 can be defined.

That is, by fitting the front metal fitting 24 into the annular recess 22, the opening of the annular recess 22 is closed in a liquid-tight state, so that there is no space inside the annular recess 22 with respect to the external space. A hermetically sealed mass storage chamber 34 is defined.

In addition, in the front metal fitting 24 as described above, as shown in FIG. 36 are arranged concentrically, and a rubber elastic body 38 is interposed between the axially opposing surfaces of the front metal fitting 24 and the damper mass 36 over the entire circumferential direction. The damper mass 36 is vulcanized and bonded to the opposing surface, and the damper mass 36 is elastically supported with respect to the front metal fitting 24 by the rubber elastic body 38 . In this embodiment, since the nut members 40.40 forming the service hole 39 for removing the damper pulley lO from the crankshaft are welded and fixed to the front metal fitting 24, these nut members 40.40 In order to avoid damping of the damper mass 36 against the damper mass 36, cutouts 42, 42 are provided in the damper mass 36.

By assembling the front metal fitting 24 to the pulley body 12 as described above, the damper mass 36 is accommodated in the mass housing chamber 34 and is concentric with the pulley body 12, as shown in FIG. At the same time, it is elastically attached to the pulley body 12 via the rubber elastic body 38, and the damper mass 36 and the rubber elastic body 38 cause the pulley body 12 to A damper mechanism 44 is constructed that can absorb and reduce vibrations in the crankshaft to which the crankshaft is attached.

In addition, in the damper mechanism 44, in response to vibrations in both the torsional direction and the bending direction generated in the crankshaft, deformation of the rubber elastic body of 3 days is caused by shearing. By adjusting the spring constant of the rubber elastic body 38 and the mass and moment of inertia of the damper mass 36 to tune the resonance frequencies in both torsional and bending directions, a vibration absorption function effective against both torsional and bending vibrations can be achieved. It will be configured as a dynamic vibration absorber that can play an active role.

Furthermore, a highly viscous fluid with high kinematic viscosity is sealed in the mass storage chamber 34 in which such a damper mechanism 44 is housed, and the damper mass 36 and the mass storage chamber 3 are sealed.
4 and the inner surface. In addition, in order to effectively obtain the shear stress described below, such a high viscosity fluid preferably has a kinematic viscosity of 5,000 centistics or more, and silicone oil or the like whose viscosity changes little over a wide temperature range. It will be suitably used.

Further, it is also possible to seal such a highly viscous fluid into the mass storage chamber 34 by press-fitting the differential fitting 24 into the pulley body 12 into the fluid. For example, when assembling the difference fitting 24 to the pulley body 12, it is difficult to remove the fluid that has been removed, so for example, it is necessary to inject a predetermined amount of fluid into the annular recess 22 or to remove the fluid from the pulley body 12. After assembling the differential fitting 24 to the pulley body 12, it is preferable to fill the fluid through an injection hole formed in the pulley body 12, and after such filling, close the injection hole with a rivet or the like.

In other words, the damper boo 1J10 with such a structure
In this case, vibration input from the crankshaft causes displacement (vibration) in the circumferential direction or in the direction perpendicular to the axis of the damper mass 36, causing the outer circumferential surface to become relative to the inner surface of the mass storage chamber 34. When the mass storage chamber 34 is displaced, a flow is induced in the highly viscous fluid sealed in the mass storage chamber 34, and a shear stress approximately proportional to the velocity gradient of this flow is generated. Based on such shear stress, a high damping force against the displacement of the damper mass 36 can be exerted.

Note that the damping force exerted based on the shear shear stress of the viscous fluid is determined by the viscosity of the viscous fluid, the area of the damper mass 36 that receives the shear stress of the viscous fluid, or the shear shear stress of the viscous fluid. Tuning is possible by adjusting the size of the gap between the damper mass 36 and the inner surface of the mass storage chamber 34 where stress is generated.

Therefore, in the damper mechanism 44 as described above, the damping force can be exerted not only by the rubber elastic body 38 but also by the shear stress of the high viscosity fluid, and the magnitude of the damping force is determined by the damper mechanism 44. Since tuning is possible by adjusting the opposing area between the mass 36 and the inner surface of the mass storage chamber 34 and the distance between the opposing surfaces, a large damping coefficient can be easily set with good tunability.

Therefore, in such a damper mechanism 44,
When tuning, optimal tuning and maximum aX attenuation,
Therefore, depending on the vibration form of the crankshaft to be damped,
A damper mechanism that can suppress the vibration extremely effectively can be advantageously provided.

Further, in such a damper mechanism 44, since a sufficient damping coefficient can be set, the amount of displacement of the damper mass 36 during resonance can be reduced, and the amount of elastic deformation of the rubber elastic body 38 can be effectively suppressed. This also has the advantage that the durability of the rubber elastic body 38 and, by extension, the damper mechanism 44 can be advantageously ensured.

Furthermore, by employing silicone oil as the sealed fluid in such a damper mechanism 44, temperature changes in the damping coefficient can be effectively prevented or suppressed. Even when exposed to high heat, the desired vibration suppressing effect can be stably exhibited.

Furthermore, in the damper pulley 10 as described above, since the damper mass 36 is housed in the closed mass storage chamber 34, even if the rubber elastic body 38 breaks, the damper mass 36 can be prevented from popping out very effectively and reliably, and therefore,
It also has the advantage that safety can be advantageously ensured without providing a special fail-safe mechanism.

Moreover, in the damper mechanism 44 in this embodiment,
When vibrations are input in the torsional and bending directions from the crankshaft, deformation in the rubber elastic body 38 is caused by shearing, so it is possible to have a vibration absorption effect against re-vibrations due to torsion and bending.
In addition, since the shear stress of the viscous fluid as described above can be effectively exerted against the displacement of the damper mass 36 due to manual vibration in both directions, and a sufficient damping coefficient can be set, these torsional Furthermore, extremely good vibration absorption performance can be exhibited against re-vibration due to bending.

Next, FIGS. 5 and 6 show a damper pulley 50 which is another embodiment of the present invention and which also serves as a multi-pulley. In this embodiment, members having substantially the same structure as those in the first embodiment are designated by the same reference numerals in the drawings, and detailed explanation thereof will be omitted.

That is, in the damper pulley 50 of this embodiment, as in the first embodiment, the cylindrical portion 20 of the pulley main body 12 is thickened over approximately half the length in the axial direction. By closing the opening of the annular recess 22 formed in the annular recess 22 with the lid fitting 24, the annular recess 22 is closed.
A mass storage chamber 34 in which a predetermined high-viscosity fluid is sealed is formed within the mass storage chamber 34 , and an annular damper mass 36 is concentrically housed within the mass storage chamber 34 . By being elastically supported by the interposed rubber elastic body 38, the damper mechanism 44 can exhibit a good vibration absorption effect against re-vibration in the torsional direction and the bending direction.
is made up of.

Furthermore, in the damper pulley 50 of this embodiment, a second damper mechanism 52 is attached to the axial side of the cylindrical portion 20 of the pulley body 12 that is not thickened. This second damper mechanism 52 has a second damper mass 56 that has a thick-walled cylindrical shape and is arranged radially outwardly of a mounting tube fitting 54 that has a thin-walled cylindrical shape.
are arranged concentrically, and the mounting tube fitting 54 and the second damper mass 56 are integrally connected by a second rubber elastic body 58 interposed between their radially opposing surfaces. It is said that the structure is made up of

Then, the mounting cylindrical metal fitting 54 is press-fitted and fixed to the outer peripheral surface of the cylindrical portion 20 of the pulley main body 12.
The second damper mechanism 52 is mounted concentrically to the cylindrical portion 20. A plurality of grooves 60 extending in the circumferential direction are formed on the outer peripheral surface of the second damper mass 56, and a predetermined V-belt (not shown) is wound around the grooves 60.

In the second damper mechanism 52, when the second damper mass 56 is attached to the pulley body 12, the second damper mass 56 is elastically attached to the pulley body 12 via the second rubber elastic body 58. Since the pulley body 12 is attached to the torsional vibration of the crankshaft to which the pulley body 12 is attached, it functions as a dynamic vibration absorber that can effectively absorb vibrations.

Therefore, the damper pulley 50 in this embodiment
Even in the case of the first embodiment, the damper mechanism 4
4, since the damping coefficient can be advantageously secured based on the shear stress of the viscous fluid, the damper mechanism 44 exhibits an extremely excellent vibration absorption function against torsional vibration and bending vibration of the crankshaft. In addition, other effects similar to those of the first embodiment can be effectively produced.

Moreover, especially the damper pulley 50 in this embodiment
In addition to such a damper mechanism 44, the system further includes a second damper mechanism 52 that can effectively absorb vibrations against torsional vibrations. Vibration is absorbed more effectively,
This means that it can be reduced.

Although the embodiments of the present invention have been described in detail above, these are literal illustrations, and the present invention is not to be construed as being limited only to these specific examples.

For example, in the damper mechanism 44 in the above embodiment, the rubber elastic body 38 is vulcanized and bonded to the metal fitting 24, and is supported to the pulley body 12 via the metal fitting 24. However, the rubber elastic body 38 may be vulcanized and bonded to the inner surface of the annular recess 22 so that it is directly supported by the pulley body 12.

Further, in the damper mechanism 44 in the above embodiment, the rubber elastic body 38 was interposed between the axially opposing surfaces of the inner surface of the mass storage chamber 34 and the damper mass 36, but for example,
If such a damper mechanism is required to mainly have a vibration absorption function in the patterning direction, a rubber elastic body 38 is interposed between the inner surface of the mass storage chamber 34 and the radially opposing surface of the damper mass 36. It's okay.

Furthermore, the metal fitting 24 that closes the opening of the annular recess 22 provided in the pulley body 12 is not limited to the one having a U-shaped cross section as illustrated, but may have a thick annular plate shape. etc. can also be advantageously employed.

In addition, although not listed, the present invention can be implemented in embodiments with various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art, and such embodiments may be different from the present invention. It goes without saying that any of these are included within the scope of the present invention as long as they do not depart from the spirit of the invention.

(Effects of the Invention) As is clear from the above description, in the viscous fluid-filled damper pulley according to the present invention, the damping force in the damper mechanism is generated not only by the rubber elastic body but also by the damper pulley sealed in the mass storage chamber. This is also obtained by the shear stress of the viscous fluid, and the damping force due to the shear stress of the highly viscous fluid depends on the kinematic viscosity of the fluid and the size of the gap formed between the inside of the mass storage chamber and the mass member. Tuning is possible by adjusting the amplitude, etc., and it can be set to a sufficiently large value.

Therefore, according to the present invention, the damper mechanism can be easily and effectively designed by optimal tuning and optimal damping, thereby achieving excellent vibration suppression effects. Therefore, it is possible to advantageously provide a damper pulley equipped with a damper mechanism capable of exerting a damper mechanism, and excessive deformation of the elastic member in such a damper mechanism can be effectively prevented by the large damping force based on the shear shear stress of the high viscosity fluid. Since it can be suppressed, its durability can also be advantageously improved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view showing one embodiment of a dumbbell according to the present invention, and is a view corresponding to the 1-1 cross section in FIG. 2, and FIG. 2 is a right side view in FIG. It is a diagram. Further, FIG. 3 is an explanatory longitudinal cross-sectional view showing the pulley main body constituting the dumbbell bar shown in FIG.
The figure is an explanatory longitudinal cross-sectional view showing an integrally vulcanized molded product constituting the damper pulley shown in FIG. 1. Furthermore, FIG. 5 is a longitudinal sectional view showing another embodiment of the dumbbell according to the present invention, and is a view corresponding to the v-■ cross section in FIG. FIG. 10゜12: 20: 24: 36; 44: 50: Damper pulley Pulley main body Cylindrical part differential fitting Damper Mass damper mechanism; Boss part = 1W-shaped recess: Mass storage chamber: Rubber elastic body

Claims (1)

[Claims] The pulley body has a boss portion attached to a predetermined rotating shaft and a cylindrical portion located on the radially outer side of the boss portion and integrally connected to the pulley body, and is rotated together with the rotating shaft. By providing an annular recess that is open at one end in the axial direction and extending continuously in the circumferential direction inside the cylindrical part, and by fitting a lid body into the opening of the recess to close the opening. A sealed mass storage chamber is formed in the recess, and an annular mass member is accommodated and arranged in the mass storage chamber, and a rubber elastic body is interposed between the mass member and the inner surface of the mass storage chamber. By elastically supporting the mass member on the pulley body,
A viscous fluid-filled damper pulley forming a damper mechanism and having a mass storage chamber filled with a highly viscous fluid.