JPH07238990A - Dynamic damper and mounting structure thereof - Google Patents

Abstract

PURPOSE:To secure a dynamic damper tight to a turning shaft as well as to dispense with a one-touch clamp by turning up the free end side of a rubber clamp part outwards, and setting up the turnup end on a peripheral part of a cylindrical body. CONSTITUTION:A free end side of a rubber clamp part 24 is bent into a lap form, namely, turned up outwards, and then this turnup end 24a is installed in the peripheral part of a cylindrical body 14. With this constitution, force to be exerted toward the radial introversion from the turnup end 24a, namely, pressing force acting toward the cylindrical body 14 from this turnup end 24a is produced there, and with this force, a dynamic damper 10 is secured tight to a turning shaft 28. Therefore a one-touch clamp so far required at a time when this dynamic damper 10 is installed is this omissible. According to this method, an operator is set free from the troublesome control operation of the one-touch clamp, and further an increase in cost incurred by use of this one- touch clamp is thus solvable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a dynamic damper,
The present invention relates to a dynamic damper mounted on a rotary shaft such as a drive shaft of an automobile, and a mounting structure thereof.

[0002]

2. Description of the Related Art As is well known, an automobile is equipped with several types of rotary shafts such as a drive shaft and a propeller shaft. It is also well known that harmful vibration is generated from the rotating shaft as the rotating shaft rotates. In order to suppress this vibration, a dynamic damper is attached to the rotating shaft.

A conventional dynamic damper and its mounting will be described with reference to FIG. As shown in FIG. 4A, the dynamic damper (100) includes a cylindrical body (102) having a through hole (101) and a cylindrical mass body (103) arranged radially outward of the cylindrical body (102). Both of them (102) and (103) are spring parts (10) that extend radially outward from the outer peripheral part of the cylindrical body (102).
4) are linked together.

The cylindrical body (102) has a cylindrical mounting portion (105) extending coaxially with the cylindrical body (102) at one end (the right end in the figure).

On the inner surface of the mounting portion (105),
An annular bulge (106) is provided that projects radially inward and extends in the circumferential direction.The outer surface of the mounting part (105) corresponds to the annular bulge (106). A groove (107) extending in the circumferential direction is provided at the position.

On the other hand, the rotary shaft (108) is provided with a fitting groove (109) extending in the circumferential direction. The inner diameter of the cylindrical body (102) in the dynamic damper (100) is
Designed to be slightly smaller than the outer diameter of 8).

The dynamic damper (100) is attached to the rotary shaft (108)
When it is attached to the, the opening of the cylindrical body (102) of the dynamic damper (100) is spread out and the rotary shaft (108) is press-fitted into the through hole (101). Then, the dynamic damper (10
The ring bulge (106) of (0) is fitted to the fitting groove (109) of the rotary shaft (108).
Then, the both (100) and (108) are positioned.

After that, the one-touch clamp (110), which is a tightening tool, is placed in the groove (107) of the mounting portion (105). As a result, the dynamic damper (100) can be fixed to the rotary shaft (108).

The one-touch clamp (110) is made of metal such as iron or stainless steel and has a discontinuous ring shape having an inner diameter smaller than the outer diameter of the rotary shaft (108) (see FIG. 4 (b)). ). In other words, the one-touch clamp (110) is a kind of ring spring, and with the inner diameter widened against the spring force, apply it to the mounting part (105), return it to the original state and tighten the dynamic damper (100). It is a thing.

Although the one-touch clamp (110) makes it possible to mount the dynamic damper (100) well, on the other hand, the one-touch clamp (110), which changes depending on the vehicle model, is troublesome to manage, and the one-touch clamp (110) can be used. The use of it has caused a high cost.

A cylindrical body having a smaller inner diameter
When the rotary shaft (108) is press-fitted into the (102), the axial force of the cylindrical body (102) with respect to the rotary shaft (108) increases, so that the one-touch clamp (110) can be omitted. However, simply reducing the inner diameter of the cylindrical body (102) makes it difficult to press-fit the rotating shaft (108) due to the smaller inner diameter of the cylindrical body (102), and the workability deteriorates. No yes

[0012]

[Means for Solving the Problems] Therefore, in order to solve the above problems, the following means were taken. That is, the dynamic damper according to claim 1 is a dynamic damper including a cylindrical body into which a rotary shaft is press-fitted, and a cylindrical rubber clamp portion extends coaxially from at least one end of the cylindrical body. The free end side of the rubber clamp portion is folded back to the outside so that the folded end portion can be arranged on the outer peripheral portion of the cylindrical body.

A dynamic damper mounting structure according to a second aspect of the present invention is a mounting structure in which a rotary shaft is press-fitted into the dynamic damper, and the dynamic damper includes a cylindrical body in which the rotary shaft is arranged. A cylindrical rubber clamp portion extends coaxially from at least one end portion of the cylindrical body, and a folded end portion in which a free end side of the rubber clamp portion is folded back is arranged on an outer peripheral portion of the cylindrical body. It is a structured structure.

The dynamic damper described in claim 3 is
A dynamic damper having a rubber cylindrical body into which a rotating shaft is press-fitted, wherein the inner surface of the cylindrical body has a minute concavo-convex structure, and the cylindrical body has an expansion ratio of 7 with respect to the rotating shaft. It is formed so as to be 25%.

According to a fourth aspect of the present invention, there is provided a dynamic damper mounting structure in which a rotary shaft is press-fitted into the dynamic damper, wherein the dynamic damper includes a rubber cylindrical body having an inner surface having a minute concavo-convex structure. , And the rotary shaft is press-fitted into the cylindrical body with a spreading rate of 7 to 25%.

The spread rate (%) is calculated by the following mathematical formula.

[0017]

[Equation 1]

When the expansion ratio is less than 7% (when the inner diameter of the cylindrical body is less than 93 with respect to the outer diameter of the rotating shaft of 100), a large axial force cannot be expected.
% (When the outer diameter of the rotary shaft is 100 and the inner diameter of the cylindrical body is less than 75), it becomes difficult to press-fit the rotary shaft. The preferable range of the expansion ratio is 10 to 15% (in terms of the inner diameter of the cylindrical body, 85 to 9 with respect to the outer diameter 100 of the rotating shaft).
0).

[0019]

In the dynamic damper according to the first aspect of the present invention, the free end side of the rubber clamp portion is folded back outside after the rotary shaft is press-fitted into the cylindrical body, and the folded end portion is arranged on the outer peripheral portion of the cylindrical body. . As a result, a force acting inward in the radial direction from the folded-back end portion, that is, a pressing force acting from the folded-back end portion toward the cylindrical body is generated, and this force makes the dynamic damper strong against the rotating shaft. Since it is fixed, the one-touch clamp becomes unnecessary if the above dynamic damper is used.

In the dynamic damper mounting structure according to the second aspect of the present invention, since the folded end portion in which the free end side of the rubber clamp portion is folded back is disposed on the outer peripheral portion of the cylindrical body, the folded end portion is provided. Force that acts inward in the radial direction from the part, that is, a pressing force that acts from the folded end portion toward the cylindrical body, and this force strongly fixes the dynamic damper to the rotating shaft, so one-touch No clamp is needed.

In the dynamic damper according to a third aspect of the invention, since the inner surface of the cylindrical body has a fine concavo-convex structure, the rotary shaft can be easily press-fitted. Even if the inner diameter is so small that the expansion rate is 7 to 25%, there is no problem in press-fitting the rotary shaft.

Moreover, in the state where the dynamic damper is attached to the rotary shaft, as described above,
Since the rotary shaft is press-fitted with a high expansion ratio of 25%, the axial force of the cylindrical body with respect to the rotary shaft increases, so the pullout resistance (deviation resistance) also increases, and the one-touch clamp is no longer used. It becomes unnecessary.

It should be noted that the fact that the inner surface of the cylindrical body has a minute concavo-convex structure facilitates press-fitting of the rotating shaft because the contact area between the inner surface and the outer peripheral surface of the rotating shaft is reduced. It can be inferred that the decrease in the energy consumption is partly involved.

In the dynamic damper mounting structure according to the fourth aspect, since the inner surface of the cylindrical body of the dynamic damper has a minute concavo-convex structure, the rotary shaft can be easily press-fitted into the cylindrical body. Therefore, the inner diameter of the cylindrical body can be designed to be small so that it can be easily press-fitted, and the dynamic damper can be mounted on the rotary shaft with a high expansion rate of 7 to 25%. The dynamic damper mounted with such a high expansion ratio has a large axial attachment force to the rotating shaft, that is, a large pull-out resistance (deviation resistance), and it is not necessary to attach a one-touch clamp.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

Embodiment 1 (Implementation corresponding to claims 1 and 2)
Example) As shown in FIG. 1, the dynamic damper (10) includes a cylindrical body (14) having a through hole (12) and a radially outer side of the cylindrical body (14).
And a cylindrical mass body (16) arranged coaxially with the cylindrical body (14), both of which (14) and (16) are springs extending radially outward from the outer peripheral portion of the cylindrical body (14). They are connected by a part (18).

A plurality of the spring portions (18) are provided on the outer peripheral portion of the cylindrical body (14) and are arranged in a zigzag pattern in the circumferential direction.

The cylindrical body (14) has one side (on the right side in the drawing).
The end portion is provided with a cylindrical mounting portion (20) extending coaxially with the cylindrical body (14).

On the inner surface of the mounting portion (20),
An annular bulging portion (22) is provided which projects inward in the radial direction and extends in the circumferential direction.

The cylindrical body (14) also has a cylindrical rubber clamp portion (24) extending coaxially from the end of the mounting portion (20). The thickness of the tube wall of the rubber clamp portion (24) is smaller than that of the cylindrical body (14), whereby the rubber clamp portion (24) has flexibility.

The mass body (16), the spring portion (18), the cylindrical body (14) and the rubber clamp portion (24) are integrally molded of rubber, and are made of metal inside the mass body (16). Nari weight (26) is buried.

On the other hand, as shown in FIG. 2, a rotary shaft (28) such as a drive shaft or a propeller shaft of an automobile is
A fitting groove (30) extending in the circumferential direction is provided. In addition,
The inner diameter of the cylindrical body (14) of the dynamic damper (10) is designed to be slightly smaller than the outer diameter of the rotary shaft (28) (the outer diameter of the portion excluding the fitting groove (30)).

When the dynamic damper (10) is attached to the rotary shaft (28), the opening of the cylindrical body (14) of the dynamic damper (10) is widened to move the rotary shaft (28) into the cylindrical body (14). ) Press-fit into the through hole (12). Then, the annular bulge (22) of the dynamic damper (10) is connected to the rotary shaft (2
Fit in the fitting groove (30) of 8) and position both (10) and (28).

Then, as shown in FIG. 2, the free end side of the rubber clamp portion (24) is folded into a trumpet shape, that is, folded back to the outside, and the folded end portion (24a) is folded back to the cylindrical body (14).
It is installed on the outer periphery of the. As a result, a force exerted from the folded end portion (24a) inward in the radial direction, that is, a pressing force acting from the folded end portion (24a) toward the cylindrical body (14) is generated. The damper (10) is firmly fixed to the rotating shaft (28).

In this embodiment, the rubber clamp portion (24) is provided at one end of the cylindrical body (14), but the present invention is not limited to this.
It can also be provided at both ends. By providing the rubber clamp parts (24) at both ends of the cylindrical body (14), the rotation shaft (2
The dynamic damper (10) is attached more firmly to the 8) and the pullout resistance (deviation resistance) is further increased.

Example 2 (Implementation corresponding to claims 3 to 4)
Example) The present Example 2 differs from the above Example 1 in the following points. That is, the inner surface of the cylindrical body (14) having no rubber clamp portion (24) has a minute concavo-convex structure, and the inner diameter of the cylindrical body (14) is designed to be slightly smaller.

Hereinafter, these points will be described.

As shown in FIG. 3, a large number of irregularities are provided on the inner surface (14a) of the cylindrical body (14) of the dynamic damper (10). The method of providing the inner surface (14a) with irregularities is not particularly limited, but in the case of the present embodiment, the method of knurling is adopted.

As a result, the inner surface (14a) of the cylindrical body (14)
In the above, a large number of ring-shaped engraved lines (32) (32) ... Which extend at an angle of about 45 ° to the left and right with respect to the axial direction are provided at predetermined intervals in the axial direction. Although not shown in the figure, instead of the ring-shaped engraving line (32) described above, a right-handed engraved line and a left-handed engraved line that extend spirally on the inner surface (14a) may be provided. Alternatively, the inner surface (14
In a), it is possible to provide a large number of score lines extending in the axial direction and a large number of score lines extending in the circumferential direction. In any case, the part of the engraved line provided by the knurling becomes the concave part (34), and the part surrounded by the engraved line becomes the convex part (36).

The depth of the ridges and valleys in the concave portion (34) and the convex portion (36), that is, the depth of the engraved line (32) is not particularly limited, but in the case of this embodiment, it is 0.1-1. It is 0.0 mm. When the depth is less than 0.1 mm, the concavo-convex structure becomes unclear, and the effect of facilitating press-fitting of the rotary shaft may be diminished. If it exceeds 1.0 mm,
The relationship between the dynamic damper (10) and the rotating shaft (28) is adversely affected, and in some cases, the dynamic damper (10) attached to the rotating shaft (28) may be displaced on the rotating shaft.

The inner diameter of the cylindrical body (14) (minimum inner diameter between the convex portions) is smaller than that of the conventional one, and when the outer diameter of the rotary shaft (28) is 100, it is 75 to 93. Is designed.

As described above, the dynamic damper (1
Since the inner surface (14a) of the cylindrical body (14) of (0) has a minute concavo-convex structure, it is easy to press fit the rotary shaft (28) into the cylindrical body (14), and the inner diameter of the cylindrical body (14) is Even if it is made small, the rotating shaft (28) can be press-fitted without difficulty.

When the dynamic damper (10) is attached to the rotary shaft (28), the dynamic damper (10) has a high expansion ratio of 7 to 25% (refer to [Equation 1] above). Since it is attached to the (28), the axial attachment force to the rotary shaft (28) is large, that is, the pullout resistance (deviation resistance) is large, and the one-touch clamp is no longer necessary.

As a method of forming the unevenness on the inner surface (14a), in addition to the method by the knurling described above, a large number of unevennesses are provided in advance at predetermined positions of the mold used for molding the dynamic damper (10). Examples thereof include a method and a method of embossing the inner surface (14a), but are not limited thereto.

[0045]

According to the first and second aspects of the present invention, the one-touch clamp, which was necessary when mounting the dynamic damper, can be omitted. As a result, the one-touch clamp can be freed from the troublesome management work, and the high cost caused by using the one-touch clamp can be eliminated.

According to the invention described in claims 3 to 4, in addition to the above-described effect that the one-touch clamp can be omitted, there is an effect that the rotary shaft can be easily press-fitted into the dynamic damper and the workability is improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a dynamic damper of the present invention.

FIG. 2 is a partial vertical cross-sectional view showing a state in which a dynamic damper is attached to a rotary shaft.

FIG. 3 is a vertical sectional view of a dynamic damper according to another embodiment.

4A is a conventional dynamic damper mounting structure, and FIG. 4B is an enlarged perspective view of a one-touch clamp.

[Explanation of symbols]

 10 ...... Dynamic damper 14 ...... Cylindrical body 14a ...... (Cylinder body) inner surface 16 ...... Mass body 18 ...... Spring part 24 ...... Rubber clamp part 24a ...... (Rubber clamp part) folded end 28 ...... Rotation axis 32 ... Marking line 34 ... Recessed portion (on inner surface of cylindrical body) 36 ... Convex portion (on inner surface of cylindrical body)

Claims (4)

[Claims] 1. A dynamic damper comprising a cylindrical body into which a rotary shaft is press-fitted, wherein a cylindrical rubber clamp portion extends coaxially from at least one end portion of the cylindrical body, A dynamic damper characterized in that the free end side is folded back to the outside, and the folded back end portion can be arranged on the outer peripheral portion of the cylindrical body. 2. A mounting structure in which a rotary shaft is press-fitted into a dynamic damper, wherein the dynamic damper includes a cylindrical body in which the rotary shaft is arranged, and from at least one end of the cylindrical body. A cylindrical rubber clamp portion extends coaxially, and a folded-back end portion in which a free end side of the rubber clamp portion is folded back is arranged on an outer peripheral portion of the cylindrical body. Mounting structure. 3. A dynamic damper comprising a rubber cylinder into which a rotary shaft is press-fitted, wherein the cylindrical body has a fine concavo-convex structure on its inner surface and is expanded with respect to the rotary shaft. A dynamic damper characterized by being formed so that the ratio is 7 to 25%. 4. A mounting structure in which a rotary shaft is press-fitted into a dynamic damper, wherein the dynamic damper is provided with a rubber cylindrical body having an inner surface having a minute concavo-convex structure, and the cylindrical shape has a spreading ratio of 7 to 25%. A mounting structure for a dynamic damper, wherein the rotary shaft is press-fitted into a body.