JP2003028234A - Dynamic damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dynamic damper that reduces a vibration level in a wide frequency range and enables lightness. SOLUTION: The dynamic damper comprises a platelike spring member 1 having a fixing portion 11 fixed to a vibrating body and an extension portion 12 extended from one end of the fixing portion 11 and provided with a spring action portion at a tip, a first sub vibration system 2 composed of a first rubber elastic body 21 and a first mass member 25 and disposed on a mounting base portion 17 (spring action portion) of the platelike spring member 1, and a second sub vibration system 3 composed of a second rubber elastic body 31 and a second mass member 35 and disposed on a mounting base portion 18 (spring action portion) of the platelike spring member 1 for a resonance frequency f3 set different from a resonance frequency f2 of the first sub vibration system 2. The first sub vibration system 2 and second sub vibration system 3 arranged in parallel are disposed in series with the platelike spring member 1 to form a main vibration system of a resonance frequency f1 .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamic damper mounted on a vibration body of an automobile, for example, to suppress harmful vibration generated in the vibration body.

[0002]

2. Description of the Related Art In automobiles, many harmful vibrations such as engine vibrations and resonances generated between the engine and the vehicle body are present. Therefore, in order to suppress those harmful vibrations, various vibration preventing devices have been used. Proposed (Actual Development Sho 59
No. 158739, Japanese Utility Model Publication No. 4-47464, etc.). As such a vibration preventing device, for example, dynamic dampers as shown in FIGS. 7 to 9 have been conventionally known. The dynamic damper includes a metal mounting member 81 having a fixed portion 81a and a support wall portion 81b rising from one end of the fixed portion 81a, and a block-shaped rubber elastic body 82 fixed to a wall surface of the support wall portion 81b. , A mass member 83 fixed to the rubber elastic body 82 and elastically supported by the rubber elastic body 82.

This dynamic damper is used for the vibration of automobiles.
By fixing the mounting member 81 to the body with mounting bolts etc.
It is attached and forms a new vibration system for the vibrating body.
As a result, the vibration characteristics of the vibrating body can be measured, for example, by
From the state shown by the solid line in F to the state shown by the dashed line in the same graph
Can be changed to. That is, the resonance frequency f₁Shake
Dynamic peak P₁Is there a state where there is only one
, The vibration peak P₁Are dispersed and the resonance frequency f₁High
Anti-resonance frequency f on the frequency side and low frequency side₂, F ₃Shaking
Dynamic peak P₂, P₃In the state shown by the alternate long and short dash line
Can be changed. As a result, the resonance frequency f₁To
It is possible to significantly reduce the vibration level in
It

The resonance frequency f _n of this dynamic damper is basically determined by the spring constant k of the rubber elastic body 82 and the mass m of the mass member 83 based on the following equation 1.

F _n = √ (k / m) / 2π ... Equation 1

[0006]

However, in the above-mentioned conventional dynamic damper, by setting the resonance frequency f ₁ of the dynamic damper in accordance with the vibration frequency to be reduced, the vibration level of the resonance frequency f ₁ can be made effective. Although it can be reduced, anti-resonance appears on the high frequency side and the low frequency side of the resonance frequency f ₁ , and the amplified vibration peaks P ₂ and P ₃ are formed in the anti-resonance frequency range. Becomes Therefore, the vibration level can be effectively reduced only in an extremely narrow frequency range near a certain resonance frequency, and the vibration level cannot be effectively reduced as a whole in a wide frequency range.

Further, in the above-mentioned conventional dynamic damper, the mounting member 81 must have sufficient rigidity so that the rubber elastic body 82 exhibits a predetermined spring action at the time of resonance thereof. From the mounting member 8
1 is formed of a highly rigid metal plate made of, for example, an iron-based metal. However, since such a metal mounting member 81 is heavy, it cannot meet the recent demand for weight reduction in automobiles and the like.

The present invention has been devised in view of the above situation, and an object thereof is to provide a dynamic damper capable of reducing the vibration level in a wide frequency range and reducing the weight. is there.

[0009]

Means for Solving the Problem, Action and Effect of the Invention A dynamic damper according to the invention for solving the above-mentioned problems is a fixed portion fixed to a vibrating body and extending from one end of the fixed portion. A plate-shaped spring member having an extension portion at the tip of which a spring action portion is formed, a rubber elastic body fixed to the spring action portion of the plate spring member, and a mass member elastically supported by the rubber elastic body. And a plurality of sub-vibration systems set so that the eigenvalues of the resonance frequencies are different from each other, and the plurality of sub-vibration systems arranged in parallel are installed in series with the plate-shaped spring member. Therefore, the means that the main vibration system is formed is adopted.

The dynamic damper of the present invention is a main vibration system formed by a plurality of sub-vibration systems composed of a rubber elastic body and a mass member, a plurality of sub-vibration systems which also function as mass bodies, and a plate-shaped spring member. And are configured to have.
Therefore, by setting the eigenvalue of the resonance frequency of each vibration system according to the vibration frequency to be reduced,
It is possible to satisfactorily reduce the vibration level in a wide frequency range.

Further, in the dynamic damper of the present invention, the plate-shaped spring member on which a plurality of sub-vibration systems are installed does not need high rigidity in order to have a predetermined spring force. Since the shaped spring member can be formed of a thinner metal plate, it is possible to achieve a sufficient weight reduction.

Therefore, according to the dynamic damper of the present invention, the vibration level can be reduced in a wide frequency range and the weight can be reduced.

The plate-shaped spring member according to the present invention has a fixing portion fixed to the vibrating body and an extending portion extending from one end of the fixing portion and having a spring action portion formed at the tip thereof. It is formed of a plate-shaped metal plate. The fixing portion may be provided only at one end of the plate-shaped spring member or at both ends thereof. When the fixing portion is provided only at one end portion, the other end portion of the plate-shaped spring member serves as the tip end portion of the extension portion, and the spring action portion is formed at the other end portion. Also,
When the fixing portions are provided at both ends, the central portion of the plate-shaped spring member serves as the tip portion of the extending portion, and the spring action portion is formed at the central portion.

The spring action portion here means the portion of the plate-shaped spring member where the greatest spring force is exerted and its vicinity. The extending portion of the plate-shaped spring member can adopt various shapes such as a U-shape and a meandering shape in order to appropriately set the spring constant in the spring action portion. The spring action part at the tip of the extension part where a plurality of sub-vibration systems are installed may be formed by dividing that part, or a mounting plate where the sub-vibration system is installed may be added to the spring action part. You may do it.

As the material of the plate-shaped spring member, for example, an iron-based metal, an aluminum-based metal, or the like can be adopted, and in particular, spring steel having high toughness can be preferably used. If spring steel is used, the thickness of the plate-shaped spring member can be reduced, which is also advantageous in weight reduction.

The sub-vibration system in the present invention comprises a rubber elastic body fixed to the spring action portion of the plate-shaped spring member and a mass member elastically supported by the rubber elastic body, and the resonance frequencies have different eigenvalues. A plurality of items set as above are used. The resonance frequency of each sub-vibration system is set by the spring constant of each rubber elastic body and the mass of the mass member in accordance with the above equation 1 in accordance with the vibration frequency to be reduced. The number of sub-vibration systems can be appropriately selected according to the number of vibration frequencies to be reduced, but normally, by adopting two sub-vibration systems, the vibration level is reduced in a sufficiently wide frequency range. It is possible.

The dynamic damper according to a second aspect of the present invention is the dynamic damper according to the first aspect, wherein the plurality of sub-vibration systems are composed of a first sub-vibration system and a second sub-vibration system. when the resonance frequency f ₁ of the main vibration system is set based on the spring constant of the first sub-vibration system and the second sub-vibration system of total mass and the plate spring member, the resonance frequency f ₁ By adopting a means in which the respective resonance frequencies of the first sub-vibration system and the second sub-vibration system are tuned in accordance with the anti-resonance frequencies f ₂ and f ₃ appearing on the high frequency side and the low frequency side, respectively. There is.

According to this means, by reliably reducing the vibration level of the vibration frequency to be reduced, it is possible to greatly reduce the vibration level in a state of being averaged over a wide frequency range.

According to a third aspect of the present invention, in the dynamic damper according to the first aspect, the extending portion of the plate-shaped spring member is substantially parallel to the fixing portion from one end of the fixing portion. The first parallel extending portion extending in any direction, the rising portion bent and rising at a substantially right angle from the tip of the first parallel extending portion, and the first bending portion from the tip of the rising portion to the fixed portion side. A means of having a parallel extending portion and a second parallel extending portion extending in a substantially parallel direction is adopted.

According to this means, by having the first parallel extending portion and the second parallel extending portion, the length of the arm portion up to the spring action portion formed at the tip of the extending portion is increased. can do. Therefore, the spring constant in the spring action portion of the plate-shaped spring member can be set to a smaller value, whereby the resonance frequency of the main vibration system can be set to a lower frequency.

According to a fourth aspect of the present invention, in the dynamic damper according to the first aspect, the distal end portion of the extending portion of the plate spring member is formed separately from other portions. After the sub-vibration system is installed at the tip portion, it is integrally connected to the other portion.

According to this means, when the rubber elastic body of the sub-vibration system installed at the tip portion of the extension portion is integrally vulcanized and molded together with the tip portion and the like, the molding operation is easily performed. It is also possible to reduce the cost.

According to a fifth aspect of the present invention, there is provided the dynamic damper according to the first aspect, wherein the extending portion of the plate-shaped spring member extends in a direction away from the fixing portion. A means is adopted which has a rising portion and a plurality of parallel extending portions extending in a direction parallel to the fixing portion, and is formed in a meandering state.

According to this means, since the extending portion has the plurality of parallel extending portions, the length of the arm portion up to the spring action portion formed at the tip of the extending portion can be increased. it can. Therefore, also in this case, the spring constant in the spring action portion of the plate-shaped spring member can be set smaller,
It is possible to set the resonance frequency of the main vibration system to a lower frequency.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 is a plan view showing a part of a dynamic damper according to the present embodiment in section, and FIG. 2 is a side view of the dynamic damper.

The dynamic damper of this embodiment is shown in FIG.
As shown in FIG. 2, the plate-shaped spring member 1, the first sub-vibration system 2 installed in the spring action portion of the plate-shaped spring member 1, and the first
The second sub-vibration system 3 is arranged in parallel with the sub-vibration system 2 and is installed in the spring action portion of the plate-shaped spring member 1.

The plate-shaped spring member 1 is formed in a substantially U-shape by using a strip plate-shaped spring steel (SK5, SUS304) having a plate thickness of 1.4 mm. This plate-shaped spring member 1 has a fixed portion 11 formed at one end thereof and fixed to a vibrating body (not shown), and an extended portion extending from one end of the fixed portion 11 and having a spring action portion formed at its tip. It consists of the outlet 12. The fixing portion 11 is formed in a cross shape having protruding portions 11a, 11a protruding on both sides in the width direction of the plate-shaped spring member 1, and mounting bolts (not shown) are formed on the protruding portions 11a, 11a. ) Through which mounting holes 11b, 11b are provided.

The extending portion 12 is fixed to the fixing portion 11 via the step portion 13 from one protrusion portion of the fixing portion 11 in the length direction.
A first parallel extending portion 14 extending in a direction substantially parallel to the first parallel extending portion 14, a rising portion 15 that bends and rises from the tip of the first parallel extending portion 14 at a substantially right angle, and bends from the tip of the rising portion 15 to the fixed portion 11 side. Then, the second parallel extending portion 16 extending in a direction substantially parallel to the fixing portion 11 and the first extending portion 14, and the fixing portion 11 bent at right angles from both ends of the second parallel extending portion 16 on the tip end side. It is composed of a pair of rectangular mounting portions 17 and 18 extending parallel to the side.
Tip part 16a of the tip side of the second parallel extending part 16 approximately ⅔
And the pair of rectangular mounting portions 17 and 18 are the second parallel extending portion 1
6 is formed separately from the rear end portion 16b on the rear end side of 6 and after the first sub-vibration system 2 and the second sub-vibration system 3 are installed on the pair of rectangular mounting portions 17 and 18. , The front end portion 16a and the rear end portion 1 by the fasteners 19 of the bolt and nut.
6b is bound. The extending portion 1 formed in this way
A spring action portion that exerts the largest spring force is formed on the tip end portion 16a located on the most distal end side of 2 and both rectangular attachment portions 17 and 18.

The spring constant k ₁ in the spring action portion of the plate spring member 1 is E, the Young's modulus of spring steel, the plate thickness of the extending portion 12 is h ₁ , and the width of the extending portion 12 is b _1. , Fixed part 11
Between the first rising portion 15 and the rising portion 15 (the step portion 13
(Including the length) is l ₁ , the rising portion 15 and the rectangular mounting portion 1
When the length of the second parallel extending portion 16 between the first and second parallel extending portions 7 and 18 is l ₂ , it is calculated by the following equation 2.

[0031] ^{_{k 1 = Eh 1 3 b 1}} /3 (l 1 + l 2) 3 ......... formula 2 first sub vibration system 2, a plate-shaped one of the rectangular mounting portion 17 of the spring member 1 (spring action portion) First rubber elastic body 21 fixed to the
And a first mass member 25 embedded and elastically supported in the first rubber elastic body 21.

The first rubber elastic body 21 is formed by integrally vulcanizing and molding a rubber material together with the first mass member 25, the rectangular mounting portion 17 and the like. This first rubber elastic body 2
Reference numeral 1 denotes a block-shaped main body portion 2 which is vulcanized and adhered to the outer surface of the rectangular mounting portion 17 and the first mass member 25 and is interposed therebetween.
2 and a covering portion 23 that covers the surface of the first mass member 25. The main body 22 is provided with a plurality of through holes 24 for adjusting the spring constant, whereby the main body 22 is set to have a predetermined spring constant k ₂ .

The first mass member 25 is made of an iron-based metal and has a rectangular parallelepiped shape, and has a predetermined mass m ₂ . The first mass member 25 is the main body portion 2 of the first rubber elastic body 21.
The main body portion 2 is arranged so as to face the rectangular mounting portion 17 with the intermediate portion 2 interposed therebetween, so that the main body portion 2 is mainly sheared and deformed.
It is elastically supported by 2.

The resonance frequency f of the first sub-oscillation system 2
₂Is the spring constant k of the first rubber elastic body 21. ₂And the first mass section
Mass 25 of material 25₂Based on
Be done.

The second sub-vibration system 3 is embedded in the second rubber elastic body 31 and the second rubber elastic body 31 fixed to the other rectangular mounting portion 18 (spring acting portion) of the plate spring member 1. The second mass member 35 is elastically supported.

The second rubber elastic body 31 is formed by integrally vulcanizing and molding a rubber material together with the second mass member 35, the rectangular mounting portion 18, and the like. This second rubber elastic body 3
Reference numeral 1 denotes a block-shaped main body portion 3 which is vulcanized and adhered to the outer surface of the rectangular attachment portion 18 and the second mass member 35 and is interposed therebetween.
2 and a covering portion 33 that covers the surface of the second mass member 35. The main body 32 is provided with a plurality of through holes 34 for adjusting the spring constant, whereby the main body 32 is set to have a predetermined spring constant k ₃ .

The second mass member 35 is made of an iron-based metal and has a rectangular parallelepiped shape, and has a predetermined mass m ₃ . The second mass member 35 is the main body portion 3 of the second rubber elastic body 31.
The main body portion 3 is arranged so as to face the rectangular mounting portion 18 with the intermediate portion 2 interposed therebetween, and thereby mainly undergoes shear deformation.
It is elastically supported by 2.

The resonance frequency f of the second auxiliary vibration system 3
₃Is the spring constant k of the second rubber elastic body 31. ₃And the second mass section
Mass of material 35 m₃Based on
Be done.

In the dynamic damper thus constructed, the first sub-vibration system 2 and the second sub-vibration system 3 which are arranged in parallel are installed in series with the plate-shaped spring member 1. A main vibration system including a mass body including the sub vibration system 2 and the second sub vibration system 3 and the plate-shaped spring member 1 is formed. The resonance frequency f ₁ of the main vibration system is adjusted to the vibration frequency f ₁ to be reduced, and the total mass m _{1 of} the first sub-vibration system 2 and the second sub-vibration system 3 and the spring constant k of the plate spring member 1 are adjusted. Based on ₁ and ₁ , it is set by the above equation 1. Further, the resonance frequency f ₂ of the first sub-vibration system 2 resonance frequency f ₃ of the second sub-vibration system 3 appears as antiresonance of the main vibration system to the high frequency side and the low frequency side of the resonance frequency f ₁ anti It is tuned to the resonance frequencies f ₂ and f ₃ .

The dynamic damper of the present embodiment configured as described above is used by being attached to the vibration body of an automobile by fixing the fixing portion 11 of the plate-shaped spring member 1 with a mounting bolt or the like. The vibration characteristics of the vibrating body are shown in FIG.
Finally, the state shown by the solid line in the graph can be changed to the state shown by the chain line in the graph. That is, from the state shown by the solid line in which only _one vibration peak P ₁ exists at the resonance frequency f ₁ due to the main vibration system of the dynamic damper,
Changes to the state shown by the dashed line peak P ₁ of the vibration is the vibration peak P _2, P ₃ of the anti-resonance frequency f _2, f ₃ to the high frequency side and the low frequency side of the resonant frequency f ₁ is dispersed is formed As a result, the vibration level at the resonance frequency f ₁ is significantly reduced.

The anti-resonance frequency f₂Vibration peak
P₂Is the anti-resonance frequency dispersed by the first sub-oscillation system 2.
f₂Re-resonance frequency on the high frequency side and low frequency side of
f_Four, F _FiveVibration peak P_Four, P_FiveIs formed by a chain line
Change to the state shown. At the same time, the anti-resonance frequency f₃
Vibration peak P₃Are dispersed by the second sub vibration system 3.
Anti-resonance frequency f₃On the high frequency side and low frequency side of
Resonance frequency f₆, F₇Vibration peak P₆, P₇Formed
Changes to the state shown by the chain line. As a result, the anti-resonance frequency
Number f₂, F₃The vibration level at
Anti-resonance frequency f_FourTo f₇In a wide frequency range up to
Significantly reduced with vibration levels generally averaged
Be done.

As described above, the dynamic damper of this embodiment has two sub-vibration systems, the first sub-vibration system 2 and the second sub-vibration system 3, and the first sub-vibration system 2 which also functions as a mass body. And the main vibration system formed by the second sub-vibration system 3 and the plate-shaped spring member 1, so that the eigenvalue of the resonance frequency of each vibration system is adjusted to the vibration frequency to be reduced. By setting each, the vibration level can be satisfactorily reduced in a wide frequency range.

In particular, in the dynamic damper of this embodiment, the resonance frequencies f ₂ and f _{3 of} the first sub-vibration system 2 and the second sub-vibration system 3 are the resonance frequencies f of the main vibration system.
_Since it is tuned to the anti-resonance frequencies f ₂ and f ₃ appearing on the high frequency side and the low frequency side of ₁ , it is possible to greatly reduce the vibration level while being averaged over a wide frequency range. You can

Further, in the dynamic damper of this embodiment, the plate-shaped spring member 1 on which the first sub-vibration system 2 and the second sub-vibration system 3 are installed is formed of a thin spring steel plate. It is possible to achieve a sufficient weight reduction.

Further, since the plate-shaped spring member 1 of this embodiment is formed in a substantially U-shape having the first parallel extending portion 14 and the second parallel extending portion 16, the extending portion is formed. the length of the portion to be the arm to the spring action portion is formed at the tip of 12 (the sum of the length l ₂ of the length l ₁ and the second parallel extension 16 of the first parallel extending portion 14) long can do. Therefore, the spring constant k ₁ in the spring action portion can be set to a smaller value, which allows the resonance frequency f ₁ of the main vibration system to be set to a lower frequency.

Further, the first mass member 25 of the first sub-vibration system 2 and the second mass member 35 of the second sub-vibration system 3 also have the main body portions 22, 32 of the first and second rubber elastic bodies 21, 31. Are arranged in a state of being elastically supported so that they are mainly sheared and deformed, so that the spring constants k ₂ and k _{3 of the} main body portions 22 and 32 are
Can be set to a smaller value, which makes it possible to set the resonance frequencies f ₂ and f ₃ of the first and second auxiliary vibration systems ₂ and ₃ to lower frequencies.

Further, the plate-shaped spring member 1 of the present embodiment has the tip end portion 16a of the second parallel extending portion 16 and the rectangular mounting portion 1.
Since 7 and 18 are formed separately from the rear end portion 16b, the molding operation for integrally vulcanizing and forming the first rubber elastic body 21 and the second rubber elastic body 31 together can be easily performed. This is also advantageous for cost reduction.

[Second Embodiment] FIG. 4 is a side view of a dynamic damper according to the present embodiment, FIG. 5 is a front view of the dynamic damper, and FIG. 6 is a partial sectional view of the dynamic damper. 5 is a sectional view taken along line VI-VI of FIG.

The dynamic damper of this embodiment is shown in FIG.
As shown in FIG. 6, the plate-shaped spring member 4, the mounting plate 5 fixed to the third parallel extending portion 48 (spring acting portion) of the plate-shaped spring member 4, and the first mounting plate 5 mounted on the mounting plate 5. It is composed of a first sub-vibration system 6 and a second sub-vibration system 7 arranged in parallel with the first sub-vibration system 6 and installed on the mounting plate 5.

The plate-shaped spring member 4 is formed of a strip plate-shaped spring steel (SK5, SUS304) having a plate thickness of 1.4 mm in a meandering state. The plate-shaped spring member 4 has a fixing portion 41 formed at one end thereof and fixed to a vibrating body (not shown), and an extending portion extending from one end of the fixing portion 41 and having a spring action portion formed at its tip. And an outlet 42. The fixing portion 41 is formed in a flat rectangular shape that is long in the lengthwise direction of the plate-shaped spring member 4, and mounting holes 41a, 41 through which mounting bolts (not shown) are inserted in the central portion in the lengthwise direction.
a is formed and each mounting hole 41a, 41a
Nuts 41b and 41b are fixed to the portion.

The extending portion 42 rises from one end of the fixed portion 41 in a state of being bent in a substantially right-angled direction, and rises up in the first rising portion 43.
And a first parallel extending portion 44 extending from the tip of the first rising portion 43 in a direction parallel to the fixing portion 41, and a first parallel extending portion 44.
From the tip of the arm, rising in a state of being bent at a right angle
From the tip of the rising portion 45 and the second rising portion 45 to the fixing portion 4
From the tip of the 2nd parallel extension part 46 which extends in the direction parallel to 1, the 3rd rising part 47 which stands up in the state bent in the substantially orthogonal direction from the front-end | tip of the 2nd parallel extension part 46, and the front end of the 3rd rise part 47. Third parallel extending portion 4 extending in a direction parallel to the fixed portion 41
8 and is formed in a meandering state. A spring action portion that exerts the largest spring force is formed on the third parallel extension portion 48 located on the most distal end side of the extension portion 42.

The spring constant k ₄ in the spring action portion of the plate-shaped spring member 1 is E, the Young's modulus of spring steel, the plate thickness of the extending portion 42 is h ₂ , and the width of the extending portion 42 is b _2. , The length of the first parallel extending portion 44 is l ₃ , and the length of the second parallel extending portion 46 is l.
₄ , when the length of the third parallel extending portion 48 between the third rising portion 47 and the mounting plate 5 is set to l ₅ , it is calculated by the following formula 3.

[0053] ^{_{k 4 = Eh 2 3 b 2}} /3 (l 3 + l 4 + l 5) 3 ......... formula 3 mounting plate 5, the plate thickness 3mm ferrous metal plate (SAPH31
0) has a U-shaped cross section. The mounting plate 5 is overlapped with the third parallel extending portion 48 (spring acting portion) of the plate-shaped spring member 4 to be bolt / nut fasteners 51a,
Mounting base 51 fixed by 51a, and mounting base 51
And a pair of rectangular attachment portions 52 and 53 extending in parallel at right angles from both ends of the.

The first sub-vibration system 6 includes a first rubber elastic body 61 fixed to one rectangular mounting portion 52 (spring acting portion) of the mounting plate 4 and a first rubber elastic body 61 elastically supported by the first rubber elastic body 61. It is composed of one mass member 65.

The first rubber elastic body 61 is formed by integrally vulcanizing and molding a rubber material together with the first mass member 65 and the mounting plate 5. The first rubber elastic body 61 is vulcanized and bonded to the inner surface of the rectangular mounting portion 52 and the first mass member 65 and is interposed between the block-shaped main body portion 62 and the first mass member 65. And a covering portion 63 for covering substantially half thereof. The main body 62 of the first rubber elastic body 61 is set to have a predetermined spring constant k ₅ .

The first mass member 65 is made of iron-based metal and has a rectangular parallelepiped shape, and has a predetermined mass m ₅ . The first mass member 65 is the main body portion 6 of the first rubber elastic body 61.
The main body portion 6 is arranged so as to face the rectangular attachment portion 52 with the two interposed therebetween, and thereby mainly undergoes shear deformation.
It is elastically supported by 2.

The resonance frequency f of the first sub-oscillation system 6
₂Is the spring constant k of the first rubber elastic body 61. _FiveAnd the first mass section
Mass 65 of material 65_FiveBased on
Be done.

The second auxiliary vibration system 7 has a second rubber elastic body 71 fixed to the other rectangular mounting portion 53 (spring acting portion) of the mounting plate 5, and a second rubber elastic body 71 elastically supported by the second rubber elastic body 71. It is composed of two mass members 75.

The second rubber elastic body 71 is formed by integrally vulcanizing and molding a rubber material together with the second mass member 75 and the mounting plate 5. The second rubber elastic body 71 is vulcanized and adhered to the inner surface of the rectangular mounting portion 53 and the second mass member 75 and is interposed between the block-shaped main body portion 72 and the second mass member 75. It is composed of a covering portion 73 for covering substantially half thereof. The main body 72 of the second rubber elastic body 71 is set to have a predetermined spring constant k ₆ .

The second mass member 75 is made of an iron-based metal and has a rectangular parallelepiped shape, and has a predetermined mass m ₆ . The second mass member 75 includes the main body portion 7 of the second rubber elastic body 71.
The main body portion 7 is arranged so as to face the rectangular mounting portion 53 with the intermediate portion 2 interposed therebetween, and thereby mainly undergoes shear deformation.
It is elastically supported by 2.

The resonance frequency f of the second sub-vibration system 7
₃Is the spring constant k of the second rubber elastic body 71. ₆And the second mass section
Mass of material 35 m₆Based on
Be done.

In the dynamic damper constructed as described above, the first sub-vibration system 6 and the second sub-vibration system 7 arranged in parallel to the plate-shaped spring member 4 are arranged in the same manner as the dynamic damper of the first embodiment. By being installed in series,
A main vibration system is formed by a mass body including the first sub vibration system 6 and the second sub vibration system 7 and the plate-shaped spring member 4. The resonance frequency f ₁ of the main vibration system is adjusted to the vibration frequency f ₁ to be reduced, and the total mass m _{1 of} the first sub-vibration system 6 and the second sub-vibration system 7 and the spring constant k of the plate-shaped spring member 4 are adjusted. ₄ is set according to the above equation 1. In addition, the resonance frequency f _{2 of} the first auxiliary vibration system 6 and the second auxiliary vibration system 7
The resonance frequency f ₃ is tuned according to the anti-resonance frequencies f ₂ and f ₃ appearing on the high frequency side and the low frequency side of the resonance frequency f ₁ as the anti-resonance of the main vibration system.

In the dynamic damper of the present embodiment configured as described above, the fixing portion 41 of the plate-shaped spring member 4 is fixed to the vibration body of the automobile with the mounting bolts or the like, as in the case of the first embodiment. The same operation and effect as the dynamic damper of the first embodiment can be obtained. That is, also in the case of the dynamic damper of the present embodiment, the vibration characteristics of the vibrating body can be changed from the state shown by the solid line in the graph of FIG. The vibration level can be significantly reduced in a state where the vibrations are averaged.
Furthermore, since the plate-shaped spring member 4 is formed of a thin spring steel plate, it is possible to achieve a sufficient weight reduction, and the same effects as in the case of the first embodiment can be obtained.

Further, since the plate-shaped spring member 4 of this embodiment is formed in a meandering state, the length of an arm portion up to the spring action portion formed at the tip of the extending portion 42 ( The length l _{3 of} the first parallel extending portion 44 and the second parallel extending portion 46
(The sum of the length l ₄ and the length l ₅ of the third parallel extending portion 48) can be made longer than in the first embodiment. Therefore, the spring constant k ₄ in the spring action portion can be set smaller than that in the first embodiment, and the resonance frequency f ₁ of the main vibration system can be set to a lower frequency.

[Brief description of drawings]

FIG. 1 is a plan view showing a part of a dynamic damper according to a first embodiment of the present invention in section.

FIG. 2 is a side view of the dynamic damper according to the first exemplary embodiment of the present invention.

FIG. 3 is a graph showing vibration characteristics of the dynamic damper according to the first exemplary embodiment of the present invention.

FIG. 4 is a side view of the dynamic damper according to the second exemplary embodiment of the present invention.

FIG. 5 is a front view of the dynamic damper according to the second exemplary embodiment of the present invention.

FIG. 6 is a partial cross-sectional view of the dynamic damper according to the second exemplary embodiment of the present invention, which is a cross-sectional view taken along the line VI-VI of FIG.

FIG. 7 is a side view of a conventional dynamic damper.

FIG. 8 is a front view of a conventional dynamic damper.

FIG. 9 is a plan view of a conventional dynamic damper.

FIG. 10 is a graph showing vibration characteristics of a conventional dynamic damper.

[Explanation of symbols]

1, 4 ... Plate-shaped spring members 2, 6 ... First auxiliary vibration system 3, 7 ... Second auxiliary vibration system 5 ... Mounting plate 11, 4
1 ... Fixed part 11a ... Overhang part 11b, 41a ... Mounting hole 1
2, 42 ... Extending portion 13 ... Step portion 14, 44 ... First parallel extending portion 1
5 ... Rising part 16, 46 ... 2nd parallel extension part 16a ... Tip part 16b ... Rear end part 17, 18, 52, 53 ... Rectangular mounting part 19, 51a ... Fastener 21 ... 1st rubber elastic body 22, 32 ... Main body 23, 33 ... Cover 2
4, 34 ... Through hole 25 ... First mass member 31 ... Second rubber elastic body 35 ... Second mass member 41b ... Nut 43 ...
1st rising part 45 ... 2nd rising part 47 ... 3rd rising part 48 ... 3rd parallel extension part 51 ... Attachment base 81
... Mounting member 81a ... Fixed part 81b ... Support wall part 82 ... Rubber elastic body 83 ... Mass member

Claims (5)

[Claims] 1. A plate-shaped spring member having a fixing portion fixed to a vibrating body and an extending portion extending from one end of the fixing portion and having a spring action portion formed at a tip thereof, and a plate-shaped spring member of the plate-shaped spring member. A plurality of sub-vibration systems, each of which is composed of a rubber elastic body fixed to the spring action portion and a mass member elastically supported by the rubber elastic body, and which are set to have different resonance frequency eigenvalues, A dynamic damper, wherein the main vibration system is formed by installing a plurality of the sub-vibration systems arranged in series with the plate-shaped spring member in series. 2. The plurality of sub-vibration systems are composed of a first sub-vibration system and a second sub-vibration system, the total mass of the first sub-vibration system and the second sub-vibration system, and the plate-shaped spring member. when the resonance frequency f ₁ is set on the basis of the spring constant of the main vibration system, in accordance with the anti-resonance frequency f _2, f ₃ appearing on the high frequency side and the low frequency side of the resonant frequency f ₁ 2. The dynamic damper according to claim 1, wherein respective resonance frequencies of the first sub-vibration system and the second sub-vibration system are tuned. 3. The extending portion of the plate-shaped spring member includes a first parallel extending portion extending from one end of the fixing portion in a direction substantially parallel to the fixing portion, and a tip of the first parallel extending portion. A rising part that is bent substantially at right angles from the rising part and a second parallel extending part that is bent from the tip of the rising part toward the fixed part and extends in a direction substantially parallel to the first parallel extending part. The dynamic damper according to claim 1, wherein: 4. A distal end portion of the extending portion of the plate-shaped spring member is formed separately from another portion, and is integrated with the other portion after the sub-vibration system is installed at the distal end portion. The dynamic damper according to claim 1, wherein the dynamic damper is coupled to. 5. The extending portion of the plate-shaped spring member includes a plurality of rising portions extending in a direction away from the fixing portion,
The dynamic damper according to claim 1, wherein the dynamic damper has a plurality of parallel extending portions extending in a parallel direction and the fixing portion, and is formed in a meandering state.