JP6917199B2 - Dynamic damper - Google Patents

Description

The present invention relates to a dynamic damper according to an anti-vibration technique.

In a vehicle such as an automobile, the propeller shaft that drives the rear wheels may have a sound vibration problem due to bending resonance.

As a countermeasure, as shown in FIG. 5, a shaft-interpolated dynamic damper 51 may be mounted in the hollow portion of the propeller shaft 61.

The dynamic damper 51 includes a rubber-like elastic body mounting portion 52 mounted on the inner peripheral surface of the propeller shaft 61, and a plurality of rubber feet (damper springs) on the circumference integrally provided on the inner peripheral side of the mounting portion 52. 53 has an inertial mass body (damper mass) 54 connected to the inner peripheral side of the rubber foot 53, and a reinforcing ring 55 for increasing the fitting force of the propeller shaft 61 with respect to the inner peripheral surface is provided on the mounting portion 52. It is buried.

Japanese Unexamined Patent Publication No. 2004-150543

By the way, in recent years, the natural frequency of the dynamic damper tends to shift to the low frequency side as the fuel consumption and weight of the vehicle are reduced. In order to realize low frequency characteristics, rubber feet are required to have low spring and low rigidity. However, the effect of eccentricity of the inertial mass due to rotational unbalance cannot be ignored as the rubber feet become lower in spring and rigidity, and the rubber feet become fatigued and damaged as the inertial mass displaces significantly in the radial direction. I could end up doing it.

Therefore, as shown in the comparative example of FIG. 6, in order to suppress the eccentricity of the inertial mass body, a radial stopper 56 is provided on the inner peripheral surface of the mounting portion 52 so as to face the outer peripheral surface of the inertial mass body 54 in the radial direction. It is conceivable to provide it.

However, the comparative example of FIG. 6 has room for improvement in the following points.

That is, in the comparative example of FIG. 6, since the radial stopper 56 is formed by a low-rigidity rubber-like elastic body, the eccentricity suppressing effect of the inertial mass body 54 is insufficient in the low-rigidity rubber-like elastic body. There is.

Further, if the radial clearance c between the inertial mass body 54 and the radial stopper 56 is set small in order to enhance the eccentricity suppressing effect of the inertial mass body 54 by the radial stopper 56, the dynamic damper 51 is the main function of vibration isolation. When the inertial mass body 54 swings around in order to exert the effect, the inertial mass body 54 may come into contact with the radial stopper 56, and in this case, the exertion of the anti-vibration effect may be hindered.

In view of the above points, the present invention can sufficiently exert the eccentricity suppressing effect of the inertial mass body by the radial stopper, and it is necessary to set the radial clearance between the inertial mass body and the radial stopper to be small. An object of the present invention is to provide a dynamic damper that does not hinder the vibration damping effect of the dynamic damper.

A dynamic damper shaft inserted type to be attached to the hollow portion of the rotating shaft, and the inner circumferential side metal retaining member attached to said rotary shaft, which is deposited on the outer circumferential surface of the holding member periphery The rubber portion, a plurality of outer peripheral protrusions on the circumference integrally provided on the outer peripheral surface of the outer peripheral rubber portion, the rubber feet provided on the inner peripheral side of the holding member, and the inner peripheral side of the rubber feet are connected. The inertial mass body is provided and a radial stopper is provided on the inner peripheral side of the holding member and regulates the amount of eccentricity of the inertial mass body. The radial stopper is the circumference of the holding member. a metal protrusion provided so as to protrude toward the portion upward radially inward, and is more configured with said deposited on the surface of the protrusion rubber-like elastic body made of the covering portion.

Before SL metallic holding member has a large diameter portion and the small-diameter portion of the same thickness on the circumference alternately, the small diameter portion is set to the protrusion.

The outer peripheral protrusion is provided so as to be aligned with the outer peripheral portion of the large diameter portion.

A metal protrusion provided with a radial stopper protruding inward in the radial direction on a part of the circumference of the holding member, and a rubber-like elastic covering portion adhered to the surface of the protrusion. Since it is combined with, the radial stopper has high rigidity as a whole. Therefore, the effect of suppressing the eccentricity of the inertial mass body by the radial stopper can be sufficiently exhibited.

Further, in the radial stopper with high rigidity, it is not necessary to set the radial clearance between the inertial mass body and the radial stopper to be small. Therefore, it is possible to suppress the inhibition of the anti-vibration effect of the dynamic damper due to the narrowing of the radial clearance.

It is a figure which shows the dynamic damper which concerns on 1st Embodiment, (A) is the sectional view cut by the plane in the direction perpendicular to the axis, (B) is the sectional view cut by the plane including the central axis. Graph showing the results of comparative tests It is a figure which shows the dynamic damper which concerns on 2nd Embodiment, (A) is the sectional view cut by the plane in the direction perpendicular to the axis, (B) is the sectional view cut by the plane including the central axis. It is a figure which shows the dynamic damper which concerns on 3rd Embodiment, (A) is the sectional view cut by the plane in the direction perpendicular to the axis, (B) is the sectional view cut by the plane including the central axis. A diagram showing a dynamic damper according to a conventional example, (A) is a front view thereof, and (B) is a cross-sectional view cut by a plane including the central axis thereof. It is a figure which shows the dynamic damper which concerns on the comparative example, and is the sectional view cut by the plane in the direction perpendicular to the axis.

First Embodiment ...
As shown in FIG. 1, the dynamic damper 1 according to the embodiment is a shaft insertion type / inner type dynamic damper mounted in a hollow portion of a propeller shaft 61 which is a rotating shaft.

The dynamic damper 1 has, as its components, a tubular metal holding member 11 attached to the inner peripheral side of the propeller shaft 61, a rubber-like elastic body 21 adhered (bridge-bonded) to the holding member 11. An outer peripheral rubber portion having a columnar inertial mass 31 connected to the inner peripheral side of the rubber-like elastic body 21 and being adhered to the outer peripheral surface of the holding member 11 by the rubber-like elastic body 21 over the entire surface. 22, a plurality of rubber feet 23 on the circumference (5 equal parts in the figure) that are adhered to the inner peripheral surface of the holding member 11 and also adhered to the outer peripheral surface of the inertial mass body 31, and rubber feet that are adjacent to each other. Between 23 and 23, an inner peripheral covering portion 24 adhered to the outer peripheral surface of the inertial mass body 31 and a plurality of circumferential covering portions (10 equal parts in the figure) integrally provided on the outer peripheral surface of the outer peripheral rubber portion 22. The outer peripheral protrusion 25 is integrally molded.

The rubber feet 23, 23 adjacent to each other are surrounded by both rubber feet 23, 23, the inner peripheral covering portion 24, and the holding member 11, and are formed as a curly portion 41 which is a penetrating space penetrating in the axial direction. A radial stopper 42 is provided inside the curly portion 41 on the inner peripheral side of the holding member 11 to limit the amount of eccentricity (radial displacement) of the inertial mass 31 with respect to the holding member 11 to a predetermined amount. It is provided.

The radial stopper 42 includes a metal protrusion 43 integrally provided on a part of the circumference of the holding member 11 so as to project inward in the radial direction, and a surface (at least the inner peripheral surface) of the protrusion 43. ) Is combined with a covering portion 44 made of a rubber-like elastic body. The covering portion 44 is also integrally molded by the rubber-like elastic body 21.

A radial clearance c having a predetermined size is set between the radial stopper 42 and the inner peripheral covering portion 24. When the inertial mass body 31 is eccentric and this clearance c disappears in a part on the circumference, the inertial mass body 31 comes into contact with the radial stopper 42 at the inner peripheral covering portion 24, and the radial stopper 42 operates as a stopper. ..

The holding member 11 is, for example, a processed product of a sheet metal press, in which a plurality of large diameter portions 12 and small diameter portions 13 having the same thickness (constant thickness) are provided alternately on the circumference (5 equal parts in the figure), and this large diameter portion 11 is provided. The diameter portion 12 and the small diameter portion 13 are integrally connected via a step portion 14 in the radial direction. The small diameter portion 13 is a protrusion 43 in the radial stopper 42 described above. The large diameter portion 12 is arranged on the outer peripheral side of the rubber foot 23, and holds the rubber foot 23 from the outer peripheral side thereof.

The dynamic damper 1 having the above configuration absorbs bending vibration (vibration in the radial direction) generated in the propeller shaft 61 by setting a resonance system in which the rubber foot 23 is a damper spring and the inertial mass body 31 is a damper mass. It is characterized in that it is reduced and the following effects are exhibited by the above configuration.

That is, as described above, in the dynamic damper 1, the radial stopper 42 is provided with a metal protrusion 43 provided so as to project inward in the radial direction on a part of the circumference of the holding member 11. Since it is composed of a combination with a covering portion 44 made of a rubber-like elastic body adhered to the surface of the protrusion 43, it is compared with the radial stopper 56 made of only the rubber-like elastic body according to the comparative example (FIG. 6). As a result, the radial stopper 42 is made highly rigid as a whole. Therefore, the effect of suppressing the eccentricity of the inertial mass body 31 by the radial stopper 42 can be sufficiently exerted, and the amount of eccentricity of the inertial mass body 31 can be suppressed to be small as shown in the comparative test result graph of FIG. Can be done.

In the graph of FIG. 2, the horizontal axis of the graph is the rotation speed (rpm) of the propeller shaft, the vertical axis of the graph is the amount of eccentricity of the inertial mass (mm), and the vertical axis is non-eccentric (NG). A border line L indicating the lower limit of the region is set. Therefore, both the conventional example (dotted line) of FIG. 5 and the comparative example (dashed line) of FIG. 6 may exceed the border line L, but according to the embodiment (solid line), the border line L is exceeded. It has been confirmed that there is no.

Further, in the radial stopper 42 having been made highly rigid as described above, in order to suppress the amount of eccentricity of the inertial mass body 31, it is particularly adhered between the inertial mass body 31 and the radial stopper 42 (adhered to the inertial mass body 31). It is not necessary to set the radial clearance c (between the inner peripheral covering portion 24 and the radial stopper 42) to be small. Therefore, it is possible to suppress the inhibition of the anti-vibration effect of the dynamic damper 1 due to the narrowing of the radial clearance c.

Further, since the metal protrusion 43 is covered with the rubber-like elastic covering portion 44, the inertial mass 31 abuts on the radial stopper 42 at the inner peripheral covering portion 24 when the stopper is operated. When this is done, the covering portion 44 made of a rubber-like elastic body exerts a cushioning effect peculiar to the rubber material. Therefore, it is possible to prevent a loud contact sound (striking sound) from being generated.

Furthermore, in the outer peripheral rubber portion 22 adhered to the outer peripheral surface of the holding member 11, the rubber portion arranged on the outer peripheral side of the small diameter portion 13 of the holding member 11 is based on the original rubber thickness t _{1 of the outer peripheral rubber portion 22.} , Rubber thickness corresponding to the difference between the outer diameter of the large diameter portion 12 and the outer diameter of the small diameter portion 13 a rubber thickness) _{t 2} of, for the rubber thickness _{t 3} of the outer peripheral protruding portion 25 is added, is set rubber thickness _{(t 1 + t 2 + t} 3) is large, the rubber thickness _{(t 1 + t 2 + t} 3) is The rubber-like elastic body 21 set to be large can be greatly compressed and deformed in the radial direction. Therefore, the range of the inner diameter of the propeller shaft 61 to which the dynamic damper 1 can be mounted can be expanded, and the dimensional variation of the inner diameter of the propeller shaft 61 can be absorbed.

In the first embodiment, the rubber-like elastic body 21 is also filled in the groove-shaped portion surrounded by the small-diameter portion 13 and the stepped portions 14 on both sides of the holding member 11, so that the groove-shaped portion is filled. By recognizing the rubber-like elastic body 21 and the covering portion 44 adhered to the inner peripheral side of the small diameter portion 13 as an integral rubber body, the rubber body of this integral body is inside the outer peripheral rubber portion 22. It is an inner peripheral protrusion that is integrally molded so as to project inward in the radial direction on the peripheral side. Therefore, in this case, it can be said that the small diameter portion 13 of the holding member 11 is embedded in the inner peripheral protrusion portion.

Second embodiment ...
In the first embodiment, the outer peripheral protrusions 25 made of the rubber-like elastic body 21 are provided on the outer peripheral side of the large diameter portion 12 and the outer peripheral side of the small diameter portion 13 of the holding member 11, respectively. May be provided only on the outer peripheral side of the small diameter portion 13 of the holding member 11.

The dynamic damper 1 of FIG. 3 shows an example of this, in which an outer peripheral protrusion 25 made of a rubber-like elastic body 21 is provided only on the outer peripheral side of the small diameter portion 13 of the holding member 11, and is provided on the outer peripheral side of the large diameter portion 12 of the holding member 11. Is covered with a film-like or thin-film outer peripheral coating portion 26 made of a rubber-like elastic body 21.

Third Embodiment ...
In the first embodiment, the metal holding member 11 has a large diameter portion 12 and a small diameter portion 13 having the same thickness dimension alternately on the circumference, but the holding member 11 does not have the same shape. A shape may be formed in which thick-walled portions 15 and thin-walled portions 16 having a diameter dimension are alternately provided on the circumference.

The dynamic damper 1 of FIG. 4 shows an example of this, in which the holding member 11 is an extruded aluminum product or the like, and the thick portion 15 and the thin portion 16 having the same outer diameter are alternately provided on the circumference. The inner peripheral portion of the thick portion 15 that protrudes inward in the radial direction is the protrusion 43 in the radial stopper 42.

The dynamic damper 1 is used for an automobile propeller shaft. The dynamic damper 1 is also used for a hollow propulsion shaft or the like in other engines.

1 Dynamic damper 11 Holding member 12 Large diameter part 13 Small diameter part 14 Step part 15 Thick part 16 Thin wall part 21 Rubber elastic body 22 Outer circumference rubber part 23 Rubber feet 24 Inner circumference coating part 25 Outer circumference protrusion 26 Outer circumference coating 31 Inertia Mass body 41 Curly part 42 Radial stopper 43 Projection part 44 Covering part 61 Propeller shaft (rotary shaft)
c Radial clearance

Claims (2)

A shaft-interpolated dynamic damper mounted in the hollow part of the rotating shaft.
A metal holding member attached to the inner peripheral side of the rotating shaft,
The outer peripheral rubber portion adhered to the outer peripheral surface of the holding member and the outer peripheral rubber portion
A plurality of outer peripheral protrusions on the circumference integrally provided on the outer peripheral surface of the outer peripheral rubber portion,
The rubber feet provided on the inner peripheral side of the holding member and
An inertial mass body connected to the inner peripheral side of the rubber foot,
It has a radial stopper provided on the inner peripheral side of the holding member and regulating the amount of eccentricity of the inertial mass body.
The radial stopper includes a metal protrusion provided on a part of the circumference of the holding member so as to project inward in the radial direction, and a rubber-like elastic body adhered to the surface of the protrusion. is more constructed and manufacturing of the cover portion,
The metal holding member has large diameter portions and small diameter portions having the same thickness alternately on the circumference, and the small diameter portions serve as the protrusions.
The outer peripheral protrusion is provided so as to be aligned with the outer peripheral portion of the large diameter portion.
A dynamic damper that features that. In the dynamic damper according to claim 1,
The dynamic damper is characterized in that the outer peripheral protrusion is provided only on the outer peripheral portion of the small diameter portion.

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