JP2004257486A - Method for manufacturing dynamic damper and dynamic damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dynamic damper and its manufacturing method capable of being precisely tuned for each predetermined resonance frequency range and fully obtaining vibration damping effect. <P>SOLUTION: A cylindrical mass member 1 is coaxially arranged with respect to a core 4. A cavity 5 between the mass member 1 and the core 4 is composed of a plurality of pairs of zones 6, 7, 8 and 9. The cavity 5 is partitioned in the circumferential direction so that each pair of zones 6 and 7, and 8 and 9 is located point-symmetrically with respect to a shaft axis O of the cavity 5. The rubber compounds corresponding to spring constants are supplied into each zone 6, 7, 8 and 9 so that the rubber-like elastic bodies with the same spring constant are vulcanized and formed in the pairs of the point symmetrical zones 6 and 7, 8 and 9 and the elastic bodies of different spring constants are vulcanized and formed in the pair of the zones 6 and 8, 7 and 9 adjoining in the circumferential direction. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a cylindrical dynamic damper and a dynamic damper that suppress vibration of the rotary shaft in a state in which the rotary shaft is press-fitted to the rotary shaft.
[0002]
[Prior art]
Bending vibration is generated on a rotating shaft such as a drive shaft of an automobile due to imbalance in rotation, and this vibration is transmitted to the interior of the vehicle via a suspension to generate noise. In view of this, a cylindrical dynamic damper is press-fitted onto the rotating shaft to suppress vibration of the rotating shaft. That is, the natural frequency of the dynamic damper is tuned to the resonance frequency of the rotating shaft, and the vibration energy of the rotating shaft is absorbed by resonance as the vibration energy of the dynamic damper to obtain a vibration suppressing effect.
[0003]
The conventional dynamic damper is formed by vulcanizing and molding a cylindrical rubber-like elastic body which is press-fitted onto a rotating shaft on the inner peripheral surface and both ends of a single cylindrical mass member. The structure was such that the number could be set only in a single resonance frequency range. Therefore, when a plurality of vibrations having different frequencies are input, the vibration suppression effect cannot be sufficiently obtained.
[0004]
In order to solve this problem, as disclosed in Patent Document 1, a mass member having a large mass has a large spring constant in a state where a pair of cylindrical mass members having different masses are arranged in the axial direction thereof. There has been proposed a dynamic damper in which a low-mass mass member is integrally provided on a first rubber-like elastic body with a second rubber-like elastic body having a small spring constant. In this technique, as means for making the spring constants of the first rubber-like elastic body and the second rubber-like elastic body different, means for making the shapes (thickness and the like) of both rubber-like elastic bodies different is employed.
[0005]
[Patent Document 1]
JP-A-7-208550 [0006]
[Problems to be solved by the invention]
According to the above-described conventional configuration, the spring constants of the first rubber-like elastic body and the second rubber-like elastic body are made different by making the shapes different from each other, so that the spring constant that can be set is limited. As a result, the desired spring constant cannot be set accurately, and the vibration suppressing effect cannot be sufficiently obtained.
[0007]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a dynamic damper that can be tuned accurately to each desired resonance frequency range and that a sufficient vibration suppression effect can be obtained, and a method of manufacturing the same The point is to provide.
[0008]
[Means for Solving the Problems]
The configuration of the present invention is a method of manufacturing a cylindrical dynamic damper that suppresses vibration of the rotary shaft in a state where the rotary shaft is press-fitted to the outside,
A cylindrical mass member is arranged concentrically to the medium size,
The cavity between the mass member and the middle mold is formed of a plurality of pairs of sections, and one section and the other section of each pair are located point-symmetrically with respect to the axis of the cavity. Is divided in the circumferential direction,
A rubber-like elastic portion having the same spring constant is vulcanized and formed in one section and the other section of each pair, and a rubber-like elastic section having a different spring constant is vulcanized in any pair of circumferentially adjacent sections. The point is to supply each section with a rubber compound corresponding to each spring constant so as to be molded.
[0009]
By manufacturing by this means, a rubber-like elastic portion having the same spring constant is vulcanized and formed in a pair of sections having a point symmetrical positional relationship with each other, and a different spring is provided in any pair of sections adjacent in the circumferential direction. A constant rubber-like elastic portion is vulcanized. Then, the rubber-like elastic body composed of these rubber-like elastic portions is press-fitted and fitted to the rotating shaft and attached to the rotating shaft.
[0010]
As an example, the cavity is made up of two pairs of sections, and the cavities are circumferentially divided so that each pair of sections is located point-symmetrically with respect to the axis of the cavity, and a rubber compound is added to each section. When the dynamic damper is manufactured by supplying the above, the following operation can be achieved.
[0011]
That is, of the two pairs of sections, the first rubber-like elastic section and the second rubber-like elastic section are separately vulcanized and formed in a pair of sections, and the third rubber-like elastic section and the fourth rubber-like section are formed in another pair of sections. Assuming that the elastic portions are separately formed, the first rubber-like elastic portion and the second rubber-like elastic portion have the same spring constant, and the third rubber-like elastic portion and the fourth rubber-like elastic portion also have the same spring constant. Become. The first and second rubber-like elastic portions have different spring constants from the third and fourth rubber-like elastic portions.
[0012]
In a state in which the rubber-like elastic body composed of the first to fourth rubber-like elastic portions is attached to the rotation shaft, the rubber-like elastic body is, for example, smaller than a predetermined value in a direction intersecting the center of the first and second rubber-like elastic portions. Resonates at a high natural frequency to absorb the vibration of the rotating shaft, and resonates at a low natural frequency in a direction intersecting the center of the third and fourth rubber-like elastic portions. Absorb vibration. In the direction intersecting the widthwise end portions of the first and second rubber-like elastic portions and the direction intersecting the widthwise end portions of the third and fourth rubber-like elastic portions, the middle of the height is used. Resonates at the natural frequency of the value and absorbs the vibration of the rotating shaft. Thus, the natural frequency of the dynamic damper can be tuned to a plurality of resonance frequency ranges of the rotating shaft.
[0013]
Further, since the spring constant of the rubber-like elastic portion is set by the rubber compound, it is possible to form dynamic dampers having the same shape but different natural frequencies. The range of selectable spring constants is wider than that of the means for setting the spring constant depending on the shape of the rubber-like elastic body, and the desired spring constant can be accurately set. In addition, since the rubber compound is supplied between the mass member and the middle mold during vulcanization molding, the vulcanized rubber-like elastic body has a simple and simple shape of a cylindrical shape, and a manufacturing error due to a spring constant. Is difficult to appear.
[0014]
In a structure in which the rubber-like elastic body is vulcanized and molded on the entire inner peripheral surface of the mass member, and the entire inner peripheral surface of the rubber-like elastic body is pressed against the outer peripheral surface of the rotating shaft, it can be strongly fixed to the rotating shaft, Clamp members such as tightening bands can be dispensed with, the number of parts can be reduced, and the number of work steps in the work of attaching to the rotating shaft can be reduced. In addition, it is easier to prevent the mass member from wobbling in the direction of the axis of the rotating shaft and the inclination of the mass member with respect to the rotating shaft. (I.e., a portion of the rotating shaft having the largest amplitude).
[0015]
In the means for equally dividing the cavity in the circumferential direction, the ratio at which the dynamic damper resonates at a high natural frequency to absorb the vibration of the rotating shaft and the ratio at which the dynamic damper resonates at a low natural frequency to absorb the vibration of the rotating shaft The ratio can be the same.
[0016]
As a result, when the rotating shaft may vibrate in two high and low resonance frequency ranges, a state of vibrating in one resonance frequency range and a state of vibrating in the other resonance frequency range occur at the same ratio. It is advantageous when it is easy.
[0017]
In the means for partitioning the cavity unequally in the circumferential direction for each pair of sections, the ratio at which the dynamic damper resonates at a high natural frequency to absorb the vibration of the rotating shaft, and resonates at a low natural frequency. Thus, the rate of absorbing the vibration of the rotating shaft can be made different.
[0018]
As a result, when the rotating shaft may vibrate in two high and low resonance frequency ranges, the state of vibrating in one resonance frequency range and the state of vibrating in the other resonance frequency range occur at different rates. It is advantageous when it is easy. That is, when the ratio of the rotation axis vibrating in the high resonance frequency range is large, the dynamic damper can be configured to resonate at the high natural frequency and absorb the vibration of the rotation shaft in a large ratio.
[0019]
In the means for vulcanizing and forming rubber-like elastic portions having different spring constants by supplying a rubber compound having a different carbon content to a pair of circumferentially adjacent sections, respectively, Can be accurately set to a desired value.
[0020]
The dynamic damper manufactured by any one of the above means can exhibit the same operation as the operation of any one of the above means.
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 show a cylindrical dynamic damper that suppresses vibration of the drive shaft S in a state where the drive shaft S is press-fitted and externally fitted to a drive shaft S (corresponding to a rotating shaft) of an automobile.
[0022]
The dynamic damper includes a cylindrical metal mass member 1 and a cylindrical rubber-like elastic body 3 vulcanized and formed on the entire inner peripheral surface 2 side. The entire inner peripheral surface of the rubber-like elastic body 3 is pressed against the outer peripheral surface of the drive shaft S.
[0023]
The above dynamic damper is manufactured by the following method (see FIG. 3).
[1] The mass member 1 is arranged concentrically with respect to the cylindrical middle mold 4.
[0024]
[2] The cavity 5 between the mass member 1 and the middle die 4 is equally divided into four sections in the circumferential direction. That is, the cavity 5 is composed of two pairs of a pair of sections 6 and 7 and another pair of sections 8 and 9, and the pair of sections 6 and 7 are positioned with respect to the axis O of the cavity 5. The cavity 5 is divided into four parts in the circumferential direction such that the other pair of sections 8 and 9 are located point-symmetrically with respect to the axis O of the cavity 5.
[0025]
[3] A first rubber-like elastic portion 10 and a second rubber-like elastic portion 11 having the same spring constant are vulcanized and formed in the pair of sections 6 and 7 symmetrical with respect to each other (that is, one section and the other section) ( 2), a third rubber-like elastic portion 12 and a fourth rubber-like elastic portion 13 having the same spring constant are vulcanized and formed in the other pair of sections 8 and 9, and any one pair of the circumferentially adjacent ones is adjoined in the circumferential direction. Each of the sections 6, 7, 8, 9 is provided with a respective spring so that the first rubber-like elastic section 10 and the third rubber-like elastic section 12 having different spring constants are also vulcanized in the sections (for example, 6 and 8). A rubber compound corresponding to each constant is supplied. The rubber compound corresponding to each spring constant can be produced, for example, by adjusting the content of carbon in the rubber compound.
[0026]
[4] Demold after vulcanization molding.
[0027]
The rubber-like elastic body 3 is composed of the first to fourth rubber-like elastic portions 10, 11, 12, and 13, and the spring constants of the first and second rubber-like elastic portions 10, 11 and the third and fourth rubber-like elastic portions 10, 11, 12, and 13. The natural frequency of the dynamic damper can be tuned to a plurality of resonance frequency ranges of the drive shaft S by making the spring constants of the rubber-like elastic portions 12 and 13 different.
[0028]
[Another embodiment]
[1] In the above embodiment, the cavities 5 are equally divided in the circumferential direction. However, it is also possible to manufacture the dynamic damper by unequally dividing the cavities 5 in the circumferential direction for each pair of sections. FIG. 4 shows a dynamic damper manufactured by this method.
[0029]
In this dynamic damper, the widths in the circumferential direction of the first and second rubber-like elastic portions 10 and 11 and the third and fourth rubber-like elastic portions 12 and 13 are different. The widths of the first rubber-like elastic portion 10 and the second rubber-like elastic portion 11 are the same, and the widths of the third rubber-like elastic portion 12 and the fourth rubber-like elastic portion 13 are the same. Other structures are the same as those of the first embodiment.
[0030]
[2] The cavity 5 is composed of 4 pairs (or 8 pairs, 16 pairs or the like) of sections, and the sections of each pair are located point-symmetrically with respect to the axis O of the cavity. The dynamic damper can be manufactured by dividing the cavity into eight in the circumferential direction. FIG. 5 shows a dynamic damper manufactured by this method.
[0031]
In this dynamic damper, the rubber-like elastic body 3 includes first to eighth rubber-like elastic portions 10 to 17. The spring constants of the first rubber-like elastic part 10, the second rubber-like elastic part 11, the third rubber-like elastic part 12, and the fourth rubber-like elastic part 13 are the same, and the fifth rubber-like elastic part 14 and the sixth rubber-like The elastic constants of the elastic portion 15, the seventh rubber-like elastic portion 16, and the eighth rubber-like elastic portion 17 are the same. The spring constants of the first rubber-like elastic portion 10 and the like and the fifth rubber-like elastic portion 14 and the like are different.
[0032]
[3] The dynamic damper of the above [2] may be configured as follows. That is, the spring constants of the first rubber-like elastic portion 10 and the second rubber-like elastic portion 11 are set to be the same, the spring constants of the third rubber-like elastic portion 12 and the fourth rubber-like elastic portion 13 are made the same, and the fifth The spring constants of the rubber elastic portion 14 and the sixth rubber elastic portion 15 are set to be the same, and the spring constants of the seventh rubber elastic portion 16 and the eighth rubber elastic portion 17 are set to be the same. Then, the spring constants of the first rubber-like elastic part 10, the third rubber-like elastic part 12, the fifth rubber-like elastic part 14, and the seventh rubber-like elastic part 16 are made different.
[0033]
The rotating shaft is not limited to a drive shaft, but may be another rotating shaft of an automobile or a rotating shaft provided in a device other than an automobile.
[0034]
【The invention's effect】
According to the present invention, it has been possible to provide a dynamic damper that can be tuned accurately to each desired resonance frequency range and that a sufficient vibration suppression effect can be obtained, and a method of manufacturing the same.
[0035]
Means for uniformly dividing the cavity between the mass member and the middle die in the circumferential direction, and means for unequally dividing the cavity in the circumferential direction for each pair of sections include various modes of vibration of the rotating shaft. And vibration can be more easily absorbed.
[0036]
In the means for vulcanizing and molding rubber-like elastic portions having different spring constants by supplying a rubber compound having a different carbon content to a pair of circumferentially adjacent sections, respectively, The spring constant of the elastic portion can be accurately set to a desired value, and the vibration suppressing effect can be more sufficiently obtained.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a dynamic damper. FIG. 2 is a sectional view taken along line AA of FIG. 1. FIG. 3 is a perspective view showing a method of manufacturing a dynamic damper. FIG. 4 is a transverse sectional view of a dynamic damper of another embodiment. FIG. 5 is a cross-sectional view of a dynamic damper according to another embodiment.
Reference Signs List 1 Mass member 4 Middle die 5 Cavity 6, 7, 8, 9 Section 10, 11, 12, 13 Rubber-like elastic portion O Cavity axis S Rotation axis

Claims (5)

A method of manufacturing a cylindrical dynamic damper that suppresses vibration of the rotating shaft while being press-fitted to the rotating shaft,
A cylindrical mass member is arranged concentrically to the medium size,
The cavity between the mass member and the middle mold is formed of a plurality of pairs of sections, and one section and the other section of each pair are located point-symmetrically with respect to the axis of the cavity. Is divided in the circumferential direction,
A rubber-like elastic portion having the same spring constant is vulcanized and formed in one section and the other section of each pair, and a rubber-like elastic section having a different spring constant is vulcanized in any pair of circumferentially adjacent sections. A method of manufacturing a dynamic damper for supplying a rubber compound corresponding to each spring constant to each section so as to be molded. The method for manufacturing a dynamic damper according to claim 1, wherein the cavity is equally divided in the circumferential direction. The method according to claim 1, wherein the cavity is unequally divided in the circumferential direction for each pair of sections. 4. A rubber-like elastic portion having a different spring constant is vulcanized by supplying a rubber compound having a different carbon content to a pair of circumferentially adjacent sections. The method for manufacturing a dynamic damper according to any one of the above. A dynamic damper manufactured by the manufacturing method according to claim 1.

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