JP7401206B2 - dynamic damper - Google Patents

Description

The present invention relates to a dynamic damper.

As shown in FIGS. 12(A) and 12(B), the dynamic damper 51 mounted inside the hollow shaft 61 includes a mounting ring 52 arranged inside the hollow shaft 61 and fixed to the hollow shaft 61, and a mounting ring 52 mounted inside the hollow shaft 61. It has a structure in which the ring 52 is connected to a mass 53 disposed on the inner circumferential side via an elastic body 54 made of a rubber-like elastic material, and has its own characteristics in the axial direction, the direction perpendicular to the axis, the torsional direction, and the prying direction. It has a vibration frequency.

The dynamic damper 51 is installed, for example, inside a hollow propeller shaft for transmitting driving force of a vehicle such as an automobile, and reduces vibrations generated in the propeller shaft during rotation, thereby improving quietness during driving. Prevents strength reduction due to resonance of the propeller shaft itself.

Japanese Patent Application Publication No. 2003-240052

Incidentally, as vehicles become lighter in recent years, the natural frequency required for the dynamic damper 51 in the direction perpendicular to the axis tends to decrease. As the eigenvalue in the direction perpendicular to the axis decreases (lower frequency), there is a concern that the mass 53 will be greatly eccentric at the rotation speed in the normal range, and a large load will be applied to the elastic body 54, leading to damage to the elastic body 54. .

As a measure to suppress the eccentricity of the mass 53, as shown in FIGS. 13A and 13B, it is considered to provide a convex shape 55 made of a rubber-like elastic material as an eccentricity stopper on the inner peripheral surface of the mounting ring 52. According to this, the eccentricity of the mass 53 can be regulated by the mass 53 coming into contact with the convex shape 55 when an excessive load is input.

However, according to this measure, since the initial radial clearance c set between the mass 53 and the convex shape 55 is formed by the cutting die of the rubber mold for molding the elastic body 54 and the convex shape 55, the rubber Considering the maintenance and management of the mold, the minimum value of the radial clearance c is about 1 mm. Therefore, the radial clearance c cannot be set any smaller, and the eccentricity of the mass 53 cannot be suppressed any further. When the radial clearance c is 1 mm, depending on the vehicle, rotational imbalance of the propeller shaft due to eccentricity of the mass 53 becomes a problem.

In addition, since the convex shape 55 as an eccentric stopper is made of a rubber material, the convex shape 55 is compressively deformed even after the stopper is operated, as shown in the graph of FIG. 14 as a reference example (dotted line). Tolerate eccentricity. Therefore, the function as an eccentric stopper may be insufficient.

An object of the present invention is to provide a dynamic damper installed inside a hollow shaft, which can suppress the amount of mass eccentricity to a small value and is equipped with a highly rigid eccentric stopper.

One aspect of the dynamic damper includes a mounting ring that is disposed inside a hollow shaft and fixed to the hollow shaft, and is biased to one position in the axial direction with respect to the mounting ring via an elastic body made only of a rubber-like elastic material. a mass arranged to set a radial clearance with the hollow shaft; the mounting ring and the mass are connected only by the elastic body; An outer peripheral rubber part is provided that is integral with the body, and a membrane-like mass covering part that is integral with the elastic body is provided on the outer peripheral side of the mass, and when the mass is eccentric, the mass covering part The amount of eccentricity is regulated by contacting the hollow shaft through.

In a dynamic damper mounted inside a hollow shaft, the amount of mass eccentricity can be suppressed to a small value, and the dynamic damper can be provided with a highly rigid eccentric stopper.

A sectional view showing the dynamic damper of the first embodiment A sectional view showing a dynamic damper according to a second embodiment A sectional view showing a dynamic damper according to a third embodiment A sectional view showing a dynamic damper according to a fourth embodiment It is a figure which shows the dynamic damper of 5th Embodiment, (A) is its cross-sectional view, (B) is the COC line cross-sectional view, and (B) is its side view. A sectional view showing a dynamic damper according to a sixth embodiment A sectional view showing a dynamic damper according to a seventh embodiment (A) is an enlarged view of section D in Figure 7, (B) is an enlarged view of section E in Figure 7 A sectional view showing a dynamic damper according to an eighth embodiment An explanatory diagram of the length adjustment of the mounting ring in the same dynamic damper. An explanatory diagram showing another example of the buried part in the same dynamic damper These are diagrams showing the dynamic damper explained in the background art, in which (A) is a side view thereof, and (B) is a cross-sectional view thereof. These are diagrams showing the dynamic damper explained in the background art, in which (A) is a side view thereof, and (B) is a cross-sectional view thereof. Graph diagram showing the relationship between propeller shaft rotation speed and mass eccentricity

First embodiment...
As shown in FIG. 1, the dynamic damper 11 of the embodiment is a dynamic damper installed inside a hollow shaft 61 such as a propeller shaft, and reduces vibrations generated in the hollow shaft 61 during rotation. In addition to improving the quietness during operation, this also prevents a decrease in strength due to resonance of the hollow shaft 61 itself.

The dynamic damper 11 includes a mounting ring 21 that is disposed inside a hollow shaft 61 and fixed to an inner circumferential surface 62 of the hollow shaft 61, and a shaft that is connected to the mounting ring 21 through an elastic body 41 made of a rubber-like elastic material. It is arranged biased to one direction (left side in the figure), sets a radial clearance c between it and the inner circumferential surface 62 of the hollow shaft 61, and comes into contact with the inner circumferential surface 62 of the hollow shaft 61 during eccentricity. The mass 31 is provided with a mass 31 whose eccentricity is regulated by this. The mass 31 functions as an inertial mass body in the dynamic damper resonance system, and the elastic body 41 functions as a spring.

The mounting ring 21 is annularly formed of a metal material, and integrally includes a cylindrical portion 22 and an inward flange portion 23 provided radially inward from one end of the cylindrical portion 22 in the axial direction. We are prepared.

The mass 31 is formed of a metal material into a disk shape, and its outer diameter is smaller than the inner diameter of the hollow shaft 61, thereby creating a radial clearance between the mass 31 and the inner circumferential surface 62 of the hollow shaft 61, as described above. Set c. Since the radial clearance c is not formed by a cutting die of a rubber mold, its size can be made smaller than in the reference example (FIG. 13), for example, less than 1 mm. Since the mass 31 is disposed offset to one position in the axial direction with respect to the mounting ring 21 via the elastic body 41, it is held in a cantilevered manner by the mounting ring 21 and the elastic body 41.

The elastic body 41 is formed into an annular shape from a rubber-like elastic material, is arranged between the mass 31 and the mounting ring 21, and is bonded (vulcanized) to the mass 31 at one end in the axial direction. The mounting ring 21 and the mass 31 are connected as described above by being bonded (vulcanized bonding) to the flange portion 23 of the mounting ring 21 at the opposite end in the axial direction. Due to its arrangement, the elastic body 41 undergoes shear deformation in the radial direction (direction perpendicular to the axis) during operation. Since the elastic body 41 is held by the flange portion 23 rather than the cylindrical portion 22 of the attachment ring 21, its radial width is set to be large in accordance with the radial width of the flange portion 23.

An outer peripheral rubber portion 42 is provided on the outer peripheral side of the mounting ring 21. The outer peripheral rubber part 42 is formed in an annular shape from a rubber-like elastic material, is formed integrally with the elastic body 41, is adhered (vulcanized adhesive) to the outer peripheral surface of the cylindrical part 22 of the mounting ring 21, and has a hollow outer diameter. Since the inner diameter of the shaft 61 is larger than that of the shaft 61, the shaft 61 is interposed between the cylindrical portion 22 of the mounting ring 21 and the hollow shaft 61 with a radial interference. Since the outer peripheral rubber portion 42 is formed integrally with the elastic body 41, care is taken to prevent the rubber material forming these from being damaged by the corner between the cylindrical portion 22 and the flange portion 23 of the mounting ring 21. It is desirable that the corner between the cylindrical portion 22 and the flange portion 23 has a rounded shape with an arcuate cross section, as shown in the figure.

A mass covering portion 43 is provided on the outer peripheral side of the mass 31. The mass covering part 43 is formed into an annular and thin film shape of a rubber-like elastic material, is formed integrally with the elastic body 41, is adhered (vulcanized adhesive) to the outer circumferential surface 32 of the mass 31, and is attached to the outer peripheral surface 32 of the mass 31. The outer peripheral surface 32 of is coated over the entire circumference and entire surface. Since the mass covering portion 43 is formed in the shape of a thin film, it does not affect the setting of the radial clearance c.

In the dynamic damper 11 configured as described above, the mass 31 is disposed biased to one position in the axial direction with respect to the mounting ring 21 via the elastic body 41, and a radial clearance c is set between the mass 31 and the hollow shaft 61. Since the mass 31 is configured to come into contact with the hollow shaft 61 during eccentricity to restrict the amount of eccentricity, the combination of the mass 31 and the hollow shaft 61 constitutes an eccentricity stopper. In addition, since the radial clearance c in this eccentric stopper is formed small, and in the above example it is less than 1 mm, it is possible to suppress the eccentricity of the mass 31 to a smaller value than in the reference example (Fig. 13). There is. Therefore, the eccentricity of the mass 31 does not become excessive, and it is possible to suppress the problem of rotational imbalance of the propeller shaft due to the eccentricity of the mass 31.

In addition, since the eccentric stopper is a combination of the mass 31 and the hollow shaft 61, that is, a combination of metal parts, after the stopper is activated, as shown in the embodiment (solid line) in the graph of FIG. Mass 31 is not eccentric at all. Therefore, it is possible to form an eccentric stopper with high rigidity compared to the reference example (FIG. 13), and it is also possible to suppress an increase in the amount of rubber material used due to the eccentric stopper.

Furthermore, since the outer peripheral rubber portion 42 is provided on the outer peripheral side of the mounting ring 21, the mounting ring 21 can be press-fitted onto the inner periphery of the hollow shaft 61 even if there is some dimensional error in the inner diameter of the hollow shaft 61. .

Furthermore, since the membrane-like mass covering portion 43 is provided on the outer circumferential side of the mass 31, it is possible to prevent the generation of abnormal noise due to repeated contact between metal parts.

The configuration of the dynamic damper 11 of the above embodiment may be added or changed as follows.

Second embodiment...
In the dynamic damper 11 shown in FIG. 2, the mounting ring 21 includes a cylindrical portion 22, an inward flange portion 23 provided radially inward from one axial end of the cylindrical portion 22, and a cylindrical portion 22. It is integrally provided with an inward flange portion 24 provided radially inward from the end portion on the opposite side of the axial direction of the shaped portion 22 . In addition, an inner peripheral rubber part 44 is bonded (vulcanized adhesive) to the inner peripheral side of the mounting ring 21, and the mounting ring 21 is covered between the outer peripheral rubber part 42 and the inner peripheral rubber part 44 in a manner that it is sandwiched from both sides in the radial direction. (buried). The inner diameter of the inner circumferential rubber portion 44 and the inner diameter of the elastic body 41 are set to be the same size or approximately the same size.

Third embodiment...
In the dynamic damper 11 shown in FIG. 3, the mounting ring 21 integrally connects the cylindrical portion 22 and the outward flange portion 25 provided radially outward from one axial end of the cylindrical portion 22. It is supposed to be prepared for. Furthermore, the inner diameter of the cylindrical portion 22 and the inner diameter of the elastic body 41 in the attachment ring 21 are set to be the same or approximately the same size.

Fourth embodiment...
In the dynamic damper 11 shown in FIG. 4, the mounting ring 21 includes a cylindrical part 22, an outward flange part 25 provided radially outward from one axial end of the cylindrical part 22, and a cylindrical part 22. It is integrally provided with an outward flange portion 26 provided radially outward from the end portion on the opposite side in the axial direction of the shaped portion 22 . Furthermore, the inner diameter of the cylindrical portion 22 and the inner diameter of the elastic body 41 in the attachment ring 21 are set to be the same or approximately the same size.

Fifth embodiment...
In the dynamic damper 11 shown in FIG. 5, the outer peripheral rubber portion 42 is provided with a rubber flow path 45 through which the cleaning liquid passes when the damper 11 is attached to the hollow shaft 61. The rubber channel 45 is formed as a groove that passes through the outer peripheral rubber portion 42 in the axial direction, and a plurality of channels 45 exhibiting a groove shape are formed in an equally spaced shape (six equally spaced in the figure). There is. According to this configuration, since the rubber flow path 45 is provided in the outer peripheral rubber portion 42, even when the dynamic damper 11 is mounted on the inner periphery of the hollow shaft 61, the shaft can be moved from one side in the axial direction of the dynamic damper 11. It is possible to flow the cleaning liquid in the opposite direction.

Sixth embodiment...
In the dynamic damper 11 shown in FIG. 6, the mass 31 is provided with a mass flow path 33 through which the cleaning liquid passes when mounted on the hollow shaft 61. The mass flow path 33 is formed as a hole passing through the mass 31 in the axial direction, and one mass flow path 33 having a hole shape is formed at one location on the central axis of the mass 31. According to this configuration, since the mass flow path 33 is provided in the mass 31, even when the dynamic damper 11 is mounted on the inner periphery of the hollow shaft 61, the dynamic damper 11 is moved from one axial direction to the opposite axial direction. It is possible to flow the cleaning liquid to the side.

Seventh embodiment...
In the dynamic damper 11 shown in FIG. 7, the elastic body 41 is not bonded to the mass 31, and the mass holding portion 46 is integrally provided with the elastic body 41. The mass holding part 46 is formed into a membrane shape from a rubber-like elastic material, and includes an outer peripheral covering part 46a that covers the outer peripheral surface 32 of the mass 31 in a non-adhesive manner, and a peripheral covering part 46a that covers one axial end surface 34 of the mass 31 in a non-adhesive manner. The end face covering part 46b and the opposite end face covering part 46c which covers the end face 35 on the opposite side in the axial direction of the mass 31 in a non-adhesive manner are integrally formed to form a bag shape, and the mass 31 is not glued into the bag. It is held without adhesive. According to this configuration, when manufacturing the damper 11, it is possible to omit the bonding step of bonding the rubber material to the mass 31. FIG. 8(B) shows an enlarged view of section E in FIG.

Further, in the dynamic damper 11 shown in FIG. 7, the elastic body 41 and the outer peripheral rubber portion 42 are not bonded to the attachment ring 21, and the elastic body 41 is integrally provided with an attachment ring holding portion 47. The attachment ring holding portion 47 is formed into a membrane shape from a rubber-like elastic material, and includes an inner peripheral covering portion 47a that covers the inner peripheral surface of the attachment ring 21 without adhesive, and an end surface that covers the end surface of the attachment ring 21 without adhesive. The mounting ring 21 is integrally provided with a covering portion 47b and has a bag shape, and the mounting ring 21 is held in a non-adhesive manner within this bag. According to this configuration, when manufacturing the damper 11, it is possible to omit the bonding step of bonding the rubber material to the attachment ring 21. FIG. 8A shows an enlarged view of section D in FIG.

Eighth embodiment...
In the dynamic damper 11 shown in FIG. 9, the mounting ring 21 is made of a resin material instead of a metal material, thereby making it a resin mounting ring. The mounting ring 21 is formed as a cylindrical sleeve.

An outer rubber portion 42 that is integral with the elastic body 41 is provided on the outer circumference of the attachment ring 21, and an inner rubber portion 44 that is integral with the elastic body 41 is provided on the inner circumference of the attachment ring 21. Further, a plurality of (for example, five equally spaced) through holes 27 are provided on the circumference of the mounting ring 21, and the outer peripheral rubber portion 42 and the inner peripheral rubber portion 44 are directly integrated through the through holes 27.

Therefore, the mounting ring 21 is sandwiched between the outer circumferential rubber section 42 and the inner circumferential rubber section 44 and is embedded in both the rubber sections 42 and 44, and is held by both the rubber sections 42 and 44 in a non-adhesive structure. .

The resin attachment ring 21 generally has the advantage of being lighter in component weight than metal attachment rings.

Furthermore, as described above, since the connection between the mounting ring 21 and both rubber parts 42 and 44 is made in a non-adhesive structure, the process of adhering the mounting ring 21 and both rubber parts 42 and 44 can be omitted from the damper manufacturing process. I can do it. Therefore, it is possible to reduce manufacturing costs in addition to reducing parts costs by making the mounting ring 21 made of resin.

Regarding dynamic damper system items for vehicles, there are many cases in which the natural frequency is adjusted based on the evaluation results after evaluating the actual vehicle in the later stages of vehicle development. It is not easy to change the shape (manufacturing a new mold), and the only option is to make adjustments by changing the rubber hardness while leaving the specifications of the mounting ring 21 unchanged, which may lead to problems such as a low degree of freedom in design.

As a countermeasure against this, it is extremely effective to make the mounting ring 21 made of resin as described above.In other words, by adjusting the axial length of the mounting ring 21 when manufacturing the mounting ring 21, the natural frequency in the direction perpendicular to the axis of the damper can be adjusted. It is considered possible to do so.

In the example of FIG. 10, a buried portion 48 to be buried in the elastic body 41 is provided at one axial end of the mounting ring 21, and the axial length of this buried portion 48 is adjusted. By adjusting the axial length of the entire mounting ring 21, the natural frequency of the damper in the direction perpendicular to the axis can be adjusted.

Assuming that the reference value of the axial length of the entire mounting ring 21 is L ₀ , the larger the axial length of the entire mounting ring 21 (L ₀ <L ₁ ), the higher the natural frequency of the damper in the axis-perpendicular direction. Conversely, as the length of the entire mounting ring 21 in the axial direction becomes smaller (L ₀ >L ₂ ), the natural frequency of the damper in the axis-perpendicular direction becomes lower.

The shape of the buried part 48 is, in principle, an annular body that is the cylindrical sleeve-shaped mounting ring 21 extended in one direction in the axial direction. The portion 48 may be formed of a plurality of protrusions (a group of protrusions) on the circumference provided at one end of the attachment ring 21 in the axial direction. In this case, by adjusting the axial length, circumferential width, or number of projections, the natural frequency of the damper in the axis-perpendicular direction is adjusted, further expanding the degree of freedom in design. It is possible to do so.

11 Dynamic damper 21 Mounting ring 22 Cylindrical part 23, 24, 25, 26 Flange part 27 Through hole 31 Mass 32 Outer surface 33 Mass channel 34, 35 End surface 41 Elastic body 42 Outer rubber part 43 Mass covering part 44 Inner peripheral rubber Part 45 Rubber channel 46 Mass holding part 46a Outer periphery covering part 46b, 47b End face covering part 46c Opposite end face covering part 47 Mounting ring holding part 47a Inner periphery covering part 48 Embedded part 61 Hollow shaft 62 Inner peripheral surface c Radial clearance

Claims (11)

a mounting ring disposed inside a hollow shaft and fixed to the hollow shaft;
a mass that is biased to one position in the axial direction with respect to the mounting ring via an elastic body made of only a rubber-like elastic material, and that sets a radial clearance between the mass and the hollow shaft;
Equipped with
The mounting ring and the mass are connected only by the elastic body,
An outer peripheral rubber portion integral with the elastic body is provided on the outer peripheral side of the mounting ring,
A membrane-like mass covering part integrated with the elastic body is provided on the outer peripheral side of the mass,
When the mass is eccentric, the amount of eccentricity is regulated by contacting the hollow shaft through the mass covering part.
A dynamic damper characterized by: The dynamic damper according to claim 1 ,
A dynamic damper characterized in that a rubber flow path is provided that penetrates the outer peripheral rubber portion in the axial direction and allows a cleaning liquid to pass therethrough. The dynamic damper according to claim 1 ,
A dynamic damper characterized in that a mass flow path is provided that penetrates the mass in the axial direction and allows a cleaning liquid to pass therethrough. The dynamic damper according to claim 1 ,
A dynamic damper characterized in that a mass holding portion that holds the mass without adhesive is provided integrally with the elastic body. The dynamic damper according to claim 1 ,
A dynamic damper characterized in that a mounting ring holding portion that holds the mounting ring without adhesive is provided integrally with the elastic body. The dynamic damper according to any one of claims 1 to 5 ,
The dynamic damper, wherein the mounting ring is made of resin. The dynamic damper according to claim 6 ,
An outer peripheral rubber portion integral with the elastic body is provided on the outer peripheral side of the mounting ring, and an inner peripheral rubber portion integral with the elastic body is provided on the inner peripheral side of the mounting ring,
A through hole is provided in the mounting ring,
The outer peripheral rubber part and the inner peripheral rubber part are integrated through the through hole,
A dynamic damper characterized in that the outer peripheral rubber portion, the inner peripheral rubber portion, and the mounting ring are connected without adhesive. The dynamic damper according to claim 6 or 7 ,
A buried portion to be buried in the elastic body is provided at an axial end of the mounting ring,
A dynamic damper characterized in that a natural frequency of the dynamic damper in an axis-perpendicular direction can be adjusted by adjusting an axial length of the buried portion. The dynamic damper according to claim 8 ,
The buried portion consists of a plurality of circumferential protrusions provided at the axial end of the mounting ring,
A dynamic damper characterized in that the natural frequency of the dynamic damper in the axis-perpendicular direction can be adjusted by adjusting the axial length, circumferential width, or number of the protrusions. The dynamic damper according to any one of claims 1 to 5 ,
The mounting ring integrally includes an inward flange portion provided radially inward from the end facing the mass,
A dynamic damper, wherein the elastic body is held by the inward flange. The dynamic damper according to claim 1 ,
The mounting ring integrally includes an outward flange portion provided radially outward from the end facing the mass,
A dynamic damper, wherein the elastic body is held by the outward flange.

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