JP2002081494A - Vehicular vibration damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular vibration damper with a mass member arranged on a vibration member in a less displaceable manner for showing damping effect on the vibration member in response to direct and elastic abutting operation of the mass member on the vibration member and stabilizing the abutment of the mass member to the vibration member in a vertical direction. SOLUTION: The gravity center of the mass member 28 is radially deviated to a geometric center 31 of an abutment face 30 of the mass member 28 in a spherical or cylindrical shape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping device for a vehicle mounted on a vibration member of a vehicle to reduce the vibration of the vibration member, for example, a suspension member of an automobile, a subframe, a body panel, an engine unit, and a mount bracket. The present invention relates to a vehicle damping device having a novel structure that can exhibit an effective damping effect by being applied to a vibration member such as an exhaust system member.

[0002]

2. Description of the Related Art Conventionally, as a method of reducing vibration which is a problem in a vehicle such as an automobile, a mass damper for fixing a mass material to a vibration member or a dynamic method of connecting and supporting a mass material to a vibration member via a spring material is known. Dampers, and
A vibration damping material in which a sheet-like elastic material is adhered to a surface of a vibration member is known. However, both the mass damper and the dynamic damper require a large mass of mass material and have a problem that the frequency range in which an effective vibration damping effect is exhibited is narrow. In addition, the above-mentioned vibration damping material has a problem that a large attaching area is required and the weight increases. Further, the dynamic damper and the vibration damping material have a problem that it is difficult to stably obtain a target vibration damping effect because the temperature dependency of the vibration damping effect is high.

[0003] Accordingly, the present applicant has previously described the international publication WO
In Japanese Patent Application Publication No. 00/14429, an independent mass member is disposed in a non-adhesive manner relative to a housing fixed to a vibration member so as to be relatively displaceable with a gap therebetween. We propose a new structure of a vehicle damping device with a new structure that uses a sliding friction at the time of contact and energy loss due to collision to achieve a damping effect by making contact with an elastic contact surface. did. In the vehicle vibration damping device having such a structure, an effective vibration damping effect with respect to vibration over a wide frequency range can be obtained with a small mass mass.

However, as a result of further studies by the present inventors, in the vehicle vibration damping device described in International Publication WO00 / 14429, an independent mass member is housed in a housing so as to be freely displaceable. For example, if an independent mass member having a spherical or cylindrical outer peripheral surface is employed, the independent mass member is freely rotated and displaced during vibration input and moves in a complicated manner in the housing. It was recognized that the posture and the state of contact with the housing tended to be difficult to stabilize. Therefore, even when, for example, a vibration damping effect is required for vertical vibration, the independent mass member is displaced in a tilting direction or a left-right direction and comes into contact with the housing at the time of vibration input, so that the vertical mass abuts. Therefore, there is a possibility that the effective vibration damping effect for the desired vertical vibration may not be stably exhibited.

[0005]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a stable contact state in a vibration direction where an anti-vibration effect is required. It is an object of the present invention to provide a vehicle vibration damping device having a novel structure that can be stably exhibited and achieve a desired vibration damping effect.

[0006]

An embodiment of the present invention which has been made to solve such a problem will be described below. The components employed in each of the embodiments described below can be employed in any combination as possible. In addition, aspects or technical features of the present invention are not limited to those described below, but are described in the entire specification and drawings, or based on the invention ideas that can be understood by those skilled in the art from the descriptions. It should be understood that it is recognized on the basis of.

That is, according to a first aspect of the present invention, a mass member is disposed on a vibrating member in a non-adhesive and independently displaceable manner, and the mass member is provided with a spherical or cylindrical contact surface. The vibration damping device for a vehicle, wherein the mass member is directly and elastically abutted on the vibration member at least in a substantially vertical direction at the time of vibration input by being positioned opposite to the vibration member. The center of gravity of the mass member is radially offset from the geometric center of the contact surface in a cross section including the surface.

In the vehicle vibration damping device having the structure according to this aspect, the center of gravity of the mass member is deviated in the radial direction from the geometric center of the contact surface of the mass member. The mass member can be arranged in a stable state by utilizing the gravity acting on the mass member. In other words, in the initial state where no vibration is input, the mass member is arranged facing the vibration member by gravity, with the center of gravity positioned vertically below the geometric center of the contact surface of the mass member. Will be established. Also, even when the mass member is jumped and displaced by the vibration applied to the vibration member,
Since the resultant force of gravity exerted on the mass member is applied to pass through the center of gravity, the rotational displacement of the mass member is suppressed,
The displacement state of the mass member, that is, the state of hitting the vibration member in the vertical direction is stabilized. In addition, when the vibration of the vibration member converges, the mass member returns to the initial arrangement state by the action of gravity exerted as a resultant force in the vertical direction passing through the deviated center of gravity of the mass member, and is arranged in a stable state. The Rukoto.

Therefore, in such a vehicle vibration damper, the arrangement state of the mass member can be stabilized by making good use of the action of gravity. Since the state of hitting the member is also stabilized, the intended vibration damping effect based on the contact action of the mass member with the vibration member can be more stably exhibited.

[0010] Further, in such a vehicle vibration damping device,
Since the contact surface of the mass member is spherical or cylindrical, the sliding contact area of the mass member with respect to the vibration member at the time of the jump displacement is reduced, and the catching displacement resistance is reduced. The mass member is efficiently jumped and displaced at the time of the vibration input, so that the vibration damping effect based on the striking (contact) of the mass member with the vibration member can be more effectively exerted.

It is sufficient that at least one mass member is provided for one vibration member. In addition to providing a plurality of the same mass members, a plurality of mass members having different sizes, masses, shapes, and the like are provided. It is also possible to arrange the mass member on one vibration member.

According to a second aspect of the present invention, in the vehicle vibration damping device having the structure according to the first aspect, the mass member is provided around the geometric center of the contact surface with respect to the mass member. It is characterized in that a center-of-gravity adjusting member having a specific gravity different from that of the main forming member of the member is biased in the circumferential direction and fixed. In the vehicle vibration damping device having such a structure according to this aspect, the center of gravity of the mass member can be easily shifted in the radial direction from the geometric center of the contact surface of the mass member.
In addition, as such a center of gravity adjusting member, for example, when the main forming material of the mass member is an elastic material such as a rubber elastic body or an elastomer, a high specific gravity material made of a metal material such as iron or the like can be suitably adopted, The mass member can be advantageously configured by burying and fixing the high specific gravity material inside the elastic material constituting the mass member in a state where the center of gravity of the high specific gravity material is deviated from the geometric center of the mass member. .

According to a third aspect of the present invention, there is provided a vehicle vibration damping device having a structure according to the first or second aspect, wherein a thickness dimension of the mass member around a geometric center of the contact surface of the mass member is provided. Are different in the circumferential direction.
In the vehicle vibration damping device having such a structure according to this aspect, the center of gravity of the mass member can be easily deviated in the radial direction from the geometric center of the contact surface of the mass member. It is possible to obtain a mass member in which the center of gravity is positioned eccentrically without using a separate member other than the main forming material constituting the above.

According to a fourth aspect of the present invention, there is provided a vehicle vibration damping device having a structure according to any one of the first to third aspects, wherein the vibration member has a rod shape, and the mass member has a rod shape. Is cylindrical or annular, and the mass member is extrapolated to the vibrating member to form a cylindrical contact surface with the vibrating member by the inner peripheral surface of the mass member. In the vehicle vibration damping device having such a structure according to this aspect, the contact portion of the mass member can be easily formed with a simple structure with respect to the vibration member. In particular, this embodiment can be advantageously employed when the vibration member itself to be subjected to vibration isolation is in the shape of a rod, and has a desired control as compared with the case where a housing or the like for accommodating the mass member is formed. The vibration device can be realized with a simple structure. Note that the vibration member may have a solid shape or a hollow shape. Further, the outer cross-sectional shape of the vibration member is not particularly limited, and may be, for example, a circle, an ellipse, a polygon, or the like. Furthermore,
A stopper mechanism for limiting or preventing the axial displacement of the mass member with respect to the vibration member may be provided on the vibration member side.

According to a fifth aspect of the present invention, in the vehicle vibration damping device having the structure according to the fourth aspect, the vibration member is fixed to the vibration member main body by extending from the vibration member main body. That the mass member was extrapolated to the damping rod,
Features. The vibration damping device for a vehicle having such a structure according to this aspect is a vibration damping rod fixed to the vibration member main body without directly attaching the mass member to the vibration member main body to be vibration-proof. Therefore, even when the vibration member main body has a shape other than the rod shape, for example, a panel shape, the mass member can be extrapolated and mounted, and the vibration member main body can be mounted. Therefore, the degree of freedom in designing the mounting position of the mass member and the mounting structure with respect to can be greatly improved.

According to a sixth aspect of the present invention, in the vehicle vibration damping device having the structure according to the fifth aspect, the vibration member main body is an exhaust pipe of an internal combustion engine of an automobile. I do. In this aspect, since the mass member is not attached directly to the exhaust pipe, but is externally attached to the vibration damping rod protruding from the exhaust pipe,
The influence of the heat of the exhaust pipe on the mass member, the elastic material disposed at the contact portion of the mass member, or the like can be reduced or avoided, thereby stabilizing vibration damping characteristics and improving durability. Can be achieved.

According to a seventh aspect of the present invention, there is provided a vehicle vibration damping device having a structure according to the first to third aspects, wherein the vibration damping device is formed integrally or separately with the vibration member to prevent the vibration. A rigid housing to which vibration to be shaken is input is fixed to the vibrating member, a housing space is formed by the housing, and the mass member is housed and arranged in the housing space. It is characterized in that a spherical or cylindrical contact surface to the housing is formed by the surface. The vehicle vibration damping device having such a structure according to this aspect adopts the housing,
Regardless of the shape of the vibrating member, it can be advantageously employed, for example, for a vibrating member other than a rod shape. The shape of the inner surface of the housing is preferably a spherical shape or a cylindrical shape corresponding to the outer peripheral surface of the mass member, which is slightly larger than the outer peripheral surface of the mass member. Any shape that allows contact of the mass member with the housing due to minute displacement of the mass member may be used. For example, a rectangular shape or the like may be employed. Also, a plurality of mass members in one housing,
It is also possible for them to be elastically connected to one another or to be housed and arranged independently of one another.

Further, in the present invention, the material of the mass member is not particularly limited, and the rubber material is taken into consideration in consideration of the mass and the rebound resilience of the mass member so that the required vibration-proof characteristics are exhibited. In addition to being formed of an elastic material, an elastomer, or an elastic material such as a foam thereof, it may be formed of a metal material such as steel or aluminum, a hard material such as a synthetic resin, or a composite material thereof. Further, when the mass member is formed of a metal material, at least one of the contact surface of the mass member and the contact surface of the vibration member to which the mass member is brought into contact is covered with a contact layer made of an elastic material. The structure formed by attachment is suitably adopted.

Further, in the present invention, the elastic material for elastically contacting the mass member and the vibration member, that is, the material of the elastic material constituting at least one contact surface of the mass member and the vibration member is rubber. An elastic body or a synthetic resin is suitably employed. Further, the elastic material constituting the contact surface is
In order to reduce the abutment sound and obtain the vibration damping effect, ASTM
The Shore D hardness of the standard D2240 is preferably set to 80 or less, more preferably 20 to 40. Further, the contact surface between the mass member and the vibration member has a compression elastic modulus of preferably 1 to 10 ⁴ M in order to reduce the hitting sound and improve the vibration damping effect.
The loss tangent (tan δ) is preferably 10 ⁻³ or more, more preferably 0.01 to 10 at Pa, more preferably 1 to 10 ³ MPa.

In the present invention, it is desirable to set the mass of the simple substance in the mass member to 10 to 1000 g, and more preferably to 50 to 500 g. That is, by setting the mass of the mass member alone to 1000 g or less, more preferably 500 g or less, the displacement of the mass member at the time of vibration input can be easily or efficiently generated, so that it is 10 g or more, more preferably 50 g or more.
By setting g or more, a more effective vibration damping effect can be obtained based on the contact of the mass member with the vibration member.

Further, in the present invention, the maximum gap dimension (reciprocal movable distance of the mass member) between the contact surfaces of the mass member and the vibration member is preferably 0.2 to 0.2 in order to obtain an effective vibration damping effect. 1.6 mm, more preferably 0.2-1.
0 mm.

In the present invention, it is desirable that the mass of the mass member is set to be 5 to 10% of the mass of the vibration member. If the mass of the mass member is less than 5% of the mass of the vibrating member, it may be difficult to obtain an effective vibration damping effect. On the other hand, if it exceeds 10%, the weight of the entire apparatus becomes a problem. Because. When a plurality of vibration suppression devices are mounted on the vibration member, it is desirable to set the total mass of all mass members to be 5 to 10% of the mass of the vibration member.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, in order to clarify the present invention more specifically, embodiments of the present invention will be described in detail with reference to the drawings.

First, FIG. 1 schematically shows an automobile exhaust pipe 12 as a vibration member main body, provided with a vibration damping device 10 according to a first embodiment of the present invention. 2 and 3 show a cross-sectional view and a vertical cross-sectional view in which main parts are enlarged. In the following description, the vertical direction refers to the vertical direction in FIGS.

The exhaust pipe 12 has a hollow cylindrical shape. One end of the exhaust pipe 12 in the axial direction is connected to an engine 14 of the automobile, and the other end is a muffler 16.
It is connected to the. The vibration damping device 10 is attached to a middle portion of the exhaust pipe 12 in the longitudinal direction so as to protrude on the outer peripheral surface (upward in the drawing). Note that the mounting position of the vibration damping device 10 depends on the vibration to be damped.
It is desirable to set at a position that is the antinode of the vibration mode,
In the present embodiment, the vibration damping devices 10 and 10 are attached to two positions that are antinodes in the secondary vibration mode of the exhaust pipe 12.

Each of these vibration damping devices 10 has an exhaust pipe 12 as shown in FIG. 2 and FIG.
The mass holding member 18 as a vibration damping rod protruded from and fixed to the mass holding member 18 and the mass member 28 supported by the mass holding metal member 18 in a suspended state.

The mass holding member 18 has a rod portion 20 which extends straight with a solid circular cross section. The rod portion 20 is substantially parallel to one axial end (left end in FIG. 3) of the rod portion 20. A leg 22 which is bent at a right angle and extends downward is fixedly provided. The leg portion 22 is formed in a rectangular long plate shape extending in the vertical direction, and has an upper end portion integrally connected to the rod portion 20 and a lower end portion opposite to the rod portion 20. Fixing part 2 which protrudes from and extends substantially at right angles
6 are integrally formed. The fixing portion 26 has a shape of an arc plate curved in the width direction (the left-right direction in FIG. 2) along the outer peripheral surface of the exhaust pipe 12. In short, the mass holding bracket 18 includes the rod portion 20, the leg portion 22, and the fixing portion 26, and has an integral crank shape as a whole.
For example, they are integrally formed by press working or the like.

Then, the mass holding bracket 18 is fixed to the fixing portion 26.
Is overlapped on the outer peripheral surface of the exhaust pipe 12, and the fixing portion 26 is welded and fixed to the exhaust pipe 12.
It protrudes outward from the exhaust pipe 12 and is fixed. Also,
Under such a fixed state, the rod portion 20 is
2 and extend substantially horizontally.

On the other hand, the mass member 28 is made of an integrally molded rubber elastic body, and has a solid, substantially rectangular block shape as a whole. The material of the rubber elastic body forming the mass member 28 is not particularly limited, but is preferably one having a Shore D hardness of ASTM D2240, preferably 80 or less, more preferably 20 to 40. Is preferably adopted. The mass member 28
Are all chamfered in an arc shape. The mass member 28 is formed with a through-hole 30 that extends linearly through the thickness direction with a constant circular cross section. In this through hole 30, the mass member 28 is
8 is extrapolated to the rod portion 20 of the
By 0, the mass member 28 is supported in a suspended state.

The mass holding member 18 includes the mass member 2.
After the extrapolation of the rod 8, the stopper 24 is fixed to the axial end (the right end in FIG. 3) of the rod 20 by welding or the like. The stopper 24 is a metal fitting having a rectangular flat plate shape, and is welded in a state where the stopper 24 is overlapped with the axial end surface of the rod portion 20, so that the stopper 24 extends in the direction perpendicular to the axis from the rod portion 20 and is fixed. I have. Since the outer shape of the stopper portion 24 is larger than the through hole 30 of the mass member 28, the mass member 2
8 comes off from the rod portion 20 and the mass holding bracket 18
The mass member 28 can be held on the rod portion 20 by being prevented by the leg portion 22 and the stopper portion 24.

Further, the thickness of the mass member 28 is set to be shorter than the axial length of the rod portion 20 of the mass holding bracket 18, and in the present embodiment, the thickness of the mass member 28 is set. Is approximately half of the axial length of the rod portion 20. The inner diameter of the through hole 30 in the mass member 28 is determined by the rod portion 20 of the mass holding bracket 18.
Is set slightly larger than the outer diameter dimension. Thus, the mass member 28 is allowed to be slightly displaced in the direction perpendicular to the axis with respect to the rod portion 20 under the state of being supported by the rod portion 20. As is apparent from this, in the present embodiment, the inner peripheral surface of the through hole 30 and the outer peripheral surface of the rod portion 20 form the contact surface between the mass member 28 and the vibration members 12 and 18.

When the rod 20 and the through-hole 30 are positioned on the same central axis, the entire circumference is continuously formed between the outer peripheral surface of the rod 20 and the inner peripheral surface of the through-hole 30. A gap is formed. In particular, in the present embodiment, as shown in FIGS. 2 and 3, the gap size: 2δ between the inner peripheral surface of the through hole 30 and the outer peripheral surface of the rod portion 20 in a stationary state is preferably 0. 0.2 to 1.6 mm,
More preferably, it is 0.1 to 1.0 mm.

The through hole 30 in the mass member 28
Is a predetermined distance D in the long side direction (vertically upward) with respect to the center of the outer shape of the mass member 28, that is, the intersection point O of the two diagonal lines.
Are formed only at a distance from each other. The mass member 2
8 in the width direction (the left-right direction in FIG. 2)
Is approximately the same as the outer diameter dimension of. Further, the mass member 28
The dimensions in the height direction (vertical direction in FIGS. 2 and 3) are substantially the same as the dimensions in the longitudinal direction (vertical direction in FIGS. 2 and 3) of the leg portion 22 of the mass holding bracket 18. This prevents the mass member 28 from interfering with the exhaust pipe 12 while the mass member 28 is supported by the mass holding bracket 18, and the lower surface of the mass member 28 is substantially parallel to the exhaust pipe 12. Have been.

In other words, the inner peripheral surface of the through hole 30 forming the contact surface of the mass member 28 with the vibrating member is such that the center axis 31 which is the geometric center has a predetermined size with respect to the center of gravity of the mass member 28. The mass member 28 is eccentric in the long side direction.

In the vibration damping device 10 having the above-described structure, when a vibration having a vertical amplitude is generated in the exhaust pipe 12, the mass holding bracket 18 fixed to the exhaust pipe 12 is used.
Is also substantially vibrated and displaced, and vertical vibration is transmitted to the mass member 28 extrapolated to the rod portion 20, and the mass member 28 is vertically moved on the rod portion 20. By being displaced (excited), the mass member 28 strikes against the rod portion 20 and is brought into contact with the rod portion 20. As a result, the mass holding bracket 18, and hence the exhaust pipe 12, are effectively controlled. The vibration effect is exhibited.

Here, in such a vibration damping device 10, the center of gravity of the mass member 28 is positioned in the radial direction (the outer diameter of the mass member 28) from the geometric center of the contact surface of the mass member 28 (the central axis 31 of the through hole 30). Since the mass member 28 is biased toward the center (the direction of O), the mass member 28 can be disposed in a stable state using gravity. Therefore, the mass member 28
When is displaced in the vertical direction, the striking (abutment) of the mass member 28 against the rod portion 20 can be stably generated in the vertical direction that is the vibration direction to be damped. Therefore, an effective vibration damping effect can be exhibited with respect to vertical vibration to be damped in the exhaust pipe 12.

Further, an external force is applied to the mass member 28 in the width direction (horizontal direction in FIG. 2), and the mass member 28
Even when displaced in the circumferential direction of 0, the mass member 28 is returned to the initial position by gravity. Therefore, as described above, the vertical contact state of the mass member 28 with respect to the rod portion 20 can be stably exhibited, and an effective vibration damping effect against vertical vibration for the purpose of vibration isolation can be obtained. , And can be obtained stably.

Further, in the vibration damping device 10 of the present embodiment, the contact surface of the mass member 28 (the inner peripheral surface of the through hole 30) is cylindrical, and the outer peripheral surface of the rod portion 20 is cylindrical. Therefore, the trapping displacement resistance at the time of the jump displacement of the mass member 28 can be reduced, so that the mass member 28 can be efficiently jumped and displaced at the time of vibration input, and the mass member 28 can be displaced. Rod part 20
Therefore, the vibration damping effect based on the hitting (contact) with respect to can be exhibited more efficiently.

In this embodiment, the mass member 2
8 is externally mounted on the rod portion 20 of the mass holding bracket 18 protruding from the exhaust pipe 12, the influence of the heat of the exhaust pipe 12 on the mass member 28 can be reduced.
As a result, a decrease in the performance of the mass member 28 due to a change in the elastic characteristic due to a temperature change is reduced or avoided, and the intended vibration damping effect can be obtained more stably. Can also be advantageously maintained.

FIG. 4 shows the results of a hammering test performed to confirm the vibration damping effect of the vibration damping device having the above-described structure as an example.

At the time of such a test, as shown in FIGS. 5 and 6, a hollow cylindrical arm 34 was used as a test vibration member, and each of the masses had the same structure as that of the first embodiment. Two of the members 32 are externally inserted directly into the arm 34 so as to be spaced apart from each other in the axial direction, and the arm 34 is provided with rubber holes at support holes 38 provided at both ends in the longitudinal direction. String 40, 40
Arm 3 under the condition that the arm 3
4 is vibrated by striking one end of the arm 4 with a hammer, and the frequency characteristic of the vibration level of the arm 34 is determined by a pickup (acceleration sensor) 36 mounted between the two mass members 32, 32 at the central portion in the axial direction of the arm 34. The test was performed by detecting at. The material of the arm 34 is an aluminum alloy and has a mass of 400 g. Each mass member 32 used had a mass of 10 g.
Further, the through hole 30 for mounting each mass member 32 has a circular cross-section similar to the outer peripheral surface of the arm 34 and is slightly larger than the first embodiment. A gap of 2δ = 0.3 mm was formed between the inner peripheral surface of the arm and the outer peripheral surface of the arm 34 in the direction perpendicular to the axis.

In the test apparatus used for the above-mentioned test, a similar test was performed with both mass members 32, 32 removed from the arm 34. The result is shown in FIG. 4 as a comparative example.

As is clear from the measurement results shown in FIG. 4, by mounting the vibration damping device 32 having the structure according to the present invention, the vibration in the arm 34 can be changed over a specific frequency range: B. , Can be reduced by a maximum of 20 to 25 dB. In addition, from this measurement result,
It is presumed that the vibration damping effect is exerted based on the resonance action of the mass member 32.

Next, FIGS. 7 and 8 show a vibration damping device 44 as a second embodiment of the present invention. In the following description, members and parts having the same structure as the vibration damping device (10) of the first embodiment are denoted by the same reference numerals in the drawings as those of the first embodiment. Thus, detailed description thereof will be omitted.

That is, the vibration damping device 44 of the present embodiment
Compared with the vibration damping device (10) of the first embodiment, the mass member 28 has a metal weight 46 inside. This weight 46
Has a rectangular block shape, and is opposite to the through-hole 30 with respect to the outer center of the mass member 28 (O) (vertically below).
And is fixed in a buried state inside the mass member 28.

In the vibration damping device 44 having such a structure, the mass member 28 is disposed so as to be deviated in the circumferential direction about the center axis 31 of the through hole 30, so that the first The center axis 3 of the through hole 30 is larger than the mass member of the embodiment.
The distance between the center of gravity: G and the distance to L: L is set to be larger.

Therefore, in the vibration damping device 44 of the present embodiment,
Based on the effect of stabilizing the posture of the mass member 28 based on the gravitational action, the posture of the mass member 28 that is brought into contact with the rod portion 20 at the time of vibration input is stabilized, and the same effect as in the first embodiment is obtained. Any of them can be effectively used.

In this embodiment, the mass member 2
8, the center of gravity of the mass member 28 can be easily deviated further downward than in the first embodiment, thereby stabilizing the state of contact of the mass member 28 with the rod portion 20 and preventing the mass member 28 from being exerted. The stabilization of the vibration effect can be achieved more advantageously.

Next, FIG. 9 shows a vibration damping device 48 as a third embodiment of the present invention. This vibration damping device 4
Reference numeral 8 denotes a structure in which a mass member 52 is accommodated and arranged in a housing 50. In the following description, the vertical direction refers to the vertical direction in the figure.

More specifically, the housing 50 is constituted by a vehicle body 54 as a vibration member and a housing fitting 56 disposed on the upper surface of the body 54.
The housing fitting 56 has a cylindrical shape with an inverted bottom and a bottom opening, and a peripheral edge of the lower opening is a flange portion 58 bent outward. The flange portion 58 is superimposed on the upper surface of the body 54 and fixed to the body 54 by bolts 60. Here, the position where the housing fitting 56 is fixed is desirably a position corresponding to the antinode of the vibration mode when the body 54 is vibrated in the vertical direction.

Further, the housing 5 constructed as described above
In FIG. 0, the opening is covered with the body 54, so that a closed housing space 62 partitioned from the external space is formed between the body 54 and the housing fitting 56. Note that the inner diameter and the depth of the housing fitting 56 are substantially the same, and the inner diameter of the accommodation space 62 is
It is substantially the same in the radial direction and the depth direction. Further, the housing fitting 56 is formed of steel, which is a rigid material having an elastic modulus of 5 × 10 ⁴ MPa or more. Furthermore, on the overlapping surface of the flange portion 58 with the body 54,
An annular seal ring 64 that is continuous in the circumferential direction is arranged and pressed to prevent foreign matter such as water from entering the storage space 62.

Further, the mass member 52 is accommodated in the accommodation space 62 formed in the housing 50 as described above. The mass member 52 has a spherical solid block shape formed of a rubber elastic body, and has a metal weight 66 therein. This weight 66 is
It has a rectangular or circular flat plate shape.
The center is disposed so as to be deviated from O in one radial direction (downward in the figure) and spread in a direction perpendicular to the radial line. Further, the outer dimensions of the mass metal fitting 52 are slightly smaller than the inner diameters of the storage space 62 in the radial direction and the depth direction. Then, under the condition that the mass member 52 is positioned at the center in the accommodation space 62, the mass member 52
Are formed around the entire area of the mass member 52 to allow free displacement of the mass member 52. That is, FIG. 9 shows a state in which the mass member 52 is settled, and the gap dimension: δ between the side wall surface of the housing space 62 and the surface of the mass member 52 abutting on the wall surface is preferably It is preferably 0.1 to 0.8 mm, more preferably 0.1 to 0.5 mm, and the gap dimension between the upper wall surface of the housing space 62 and the surface of the mass member 52 abutting the wall surface is preferably 2δ. Is 0.2-1.6m
m, more preferably 0.2 to 1.0 mm.
Further, as the rubber elastic body forming the mass member 52, one having a Shore D hardness of ASTM D2240, preferably 80 or less, more preferably 20 to 40, on the contact surface with the housing 50 is preferred. Is preferably adopted.

In the vibration damping device 48 having such a structure, when a vertical vibration is input to the body 54, the housing 5 formed integrally with the body 54 is formed.
The mass member 52 housed and disposed in the housing 50
And jumps and displaces in the accommodation space 62 independently, and comes into contact with the housing 50 and the body 54 and hits. Thus, based on the contact of the mass member 52 with the housing 50 and the body 54, the body 54
The effect of vibration damping is exerted on the vehicle.

Here, in the vibration damping device 48, the center of gravity G of the mass member 52 is located at the geometric center of the contact surface of the mass member 52, that is, in the present embodiment, from the center O of the mass member 52. Since the mass member 52 is biased in one radial direction, the mass member 52 can be disposed in a stable state using gravity. Therefore, the mass member 52
When the mass member 52 is displaced in the vertical direction, the mass member 52 hits the housing 50 or the body 54 (abuts).
Can be stabilized.

Further, since the contact surface of the mass member 52 is spherical and the peripheral wall surface of the housing 50 is cylindrical, the sliding contact area of the mass member 52 with the housing 50 when the mass member 52 jumps is displaced. Is reduced, and the catching displacement resistance is also reduced. Accordingly, the mass member 52 is efficiently jumped and displaced when a vibration is input, and the vibration damping effect based on the hitting (contact) of the mass member 52 against the housing 50 and the body 54 can be more efficiently exerted.

Further, in this embodiment, since the mass member 52 has the weight 66 vertically below the center O of the mass member 28 inside the mass member 52, the mass member 5
The center of gravity of 2: G can be easily set to be eccentric more advantageously than the center of the mass member 52: O, and the mass member 52 can be positioned more stably in the vertical direction.

In the present embodiment, the vibration damping device 4
By disposing 8 at a position corresponding to the antinode of the vibration mode of body 54, a more effective vibration damping effect can be obtained.

FIG. 10 shows a vibration damping device 68 according to a fourth embodiment of the present invention. In the following description, the same members and parts as those of the vibration damping device (48) of the third embodiment will be described in the drawings, respectively.
The same reference numerals as in the third embodiment denote the same parts, and a detailed description thereof will be omitted.

That is, the vibration damping device 68 of the present embodiment
Compared to the vibration damping device (48) of the third embodiment, the mass member 52 does not have the weight (66) inside, that is, the mass member 52 is formed only of a rubber elastic body. A space 70 is formed inside the mass member 52. The space 70 has a spherical shape having a radial dimension sufficiently smaller than the radial dimension of the mass member 52, and its center O ′ is positioned vertically above the center O of the mass member 52. Have been.

In the vibration damping device 68 having such a structure, the space 70 of the mass member 52 is formed vertically above the center O of the mass member 52 with the center O '. The volume below the center O of the mass member 52 is sufficiently larger than the volume above the cavity 70 of the mass member 52. Thus, since the center of gravity G of the mass member 52 is positioned below the center O of the mass member 52, the mass member 52 can be stably positioned in the vertical direction.

Therefore, in the vibration damping device 68 of this embodiment having such a structure, the same effects as those of the vibration damping device (48) of the third embodiment can be effectively exhibited. .

Although some embodiments of the present invention have been described in detail above, these are merely examples, and the present invention is not to be construed as being limited to any specific description in the embodiments. Not something.

For example, in the above-described embodiment, an elastic material is used as a main forming material of the mass member, but a metal material may be used. Specifically, FIG.
Structures such as those shown in FIGS. In the following description, members and portions having the same structure as in the first embodiment are denoted by the same reference numerals in the drawings as those in the first embodiment, to thereby provide detailed descriptions thereof. Description is omitted.

First, FIGS. 11 and 12 show a vibration damping device 72 as a fifth embodiment of the present invention. The vibration damping device 72 of the present embodiment is the same as the vibration damping device (1) of the first embodiment.
The entire mass member 28 is formed of a metal material as compared with the case of (0). Further, a contact layer 74 formed of a rubber elastic body is attached to the entire outer peripheral surface of the rod portion 20.

The material of the rubber elastic body forming the contact layer 74 may be A
Shore D hardness of STM D2240 is preferably 8
Those having 0 or less, more preferably 20 to 40, are suitably employed.

In the vibration damping device 72 having such a structure, when the exhaust pipe 12 is vibrated up and down,
The mass member 28 is elastically hit against the rod portion 20 via the contact layer 74 and is brought into contact with the rod member 20, and the same vibration damping effect as in the first embodiment can be exerted by such contact. .

FIG. 13 shows a vibration damping device 76 according to a sixth embodiment of the present invention. In the vibration damping device 76 of the present embodiment, the entire mass member 52 is formed of metal as compared with the vibration damping device (68) of the fourth embodiment. In addition, contact layers 78 and 80 formed of a rubber elastic body are attached to the wall surface of the housing space 62, that is, the inner peripheral surface of the housing fitting 56 and the upper surface of the body 54.

As a material of the rubber elastic body forming these contact layers 78 and 80, the Shore D hardness of ASTM D2240 on the contact surface with the mass member 52 is preferably 80 or less, more preferably 80 or less. Those having 20 to 40 are preferably employed.

In the vibration damping device 76 having such a structure, when a vertical vibration is input to the body 54, the mass member 52 moves the housing 50 or the body 54.
Then, the elastic members (contact layers) 78 and 80 elastically hit and contact with each other, and the same effect as in the fourth embodiment can be exerted by such contact.

In the fifth embodiment, it is possible to provide a contact layer made of a rubber elastic body on the contact surface (the inner peripheral surface of the through hole 30) of the mass member 28. At that time, the contact layer 74 attached to the outer peripheral surface of the rod portion 20 is
It is not necessarily required.

Further, in the sixth embodiment, it is possible to provide a contact layer made of a rubber elastic body on the contact surface side of the mass member 52. At that time, the contact layers 78 and 80 attached to the wall surface of the accommodation space 62 do not always need to be provided.

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, the present invention can be implemented in a form in which various changes, modifications, improvements, and the like are made.
It goes without saying that all such embodiments are included in the scope of the present invention without departing from the spirit of the present invention.

[0073]

As is apparent from the above description, in the vibration damping device having the structure according to the present invention, the center of gravity of the mass member is deviated in the radial direction from the geometric center of the contact surface of the mass member. This makes it possible to dispose the mass member in a stable state using gravity, and when the mass member is displaced in the vertical direction, the mass member strikes (contacts) the vibration member. It can be stabilized. As a result, it is possible to more stably obtain the intended vibration damping effect with respect to the vibration input in the vertical direction.

[Brief description of the drawings]

FIG. 1 is a diagram showing an attached state of a vibration damping device as a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of a section taken along line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a graph showing a hammering test result of a vibration damping device having a structure according to the present invention together with a comparative example.

FIG. 5 is an explanatory diagram illustrating a test device for a hammering test.

6 is a sectional view taken along line VI-VI in FIG.

FIG. 7 is a cross-sectional view corresponding to FIG. 2, showing a vibration damping device as a second embodiment of the present invention.

8 is a sectional view taken along line VIII-VIII in FIG.

FIG. 9 is a cross-sectional view showing a vibration damping device according to a third embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a vibration damping device according to a fourth embodiment of the present invention.

FIG. 11 is a cross-sectional view illustrating a vibration damping device according to a fifth embodiment of the present invention.

12 is a sectional view taken along the line XII-XII in FIG.

FIG. 13 is a longitudinal sectional view showing a vibration damping device as a sixth embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 10 damping device 12 exhaust pipe 20 damping rod 28 mass member

Claims (13)

[Claims] 1. A mass member is disposed on a vibrating member so as to be independently displaceable in a non-adhesive manner, and the mass member is positioned opposite to the vibrating member by a spherical or cylindrical contact surface. A vibration damping device for a vehicle in which the mass member is directly and elastically abutted on the vibration member at least in a substantially vertical direction at the time of vibration input, wherein the mass is within a cross section including the contact surface. A vibration damping device for a vehicle, wherein a center of gravity of a member is displaced in a radial direction from a geometric center of a corresponding contact surface. 2. The mass member according to claim 1, wherein a center-of-gravity adjusting member having a specific gravity different from that of a main forming member of the mass member is circumferentially biased and fixed around the geometric center of the contact surface of the mass member. The vibration damping device for a vehicle according to the above. 3. The vibration damping device for a vehicle according to claim 1, wherein a thickness dimension of the contact surface of the mass member around a geometric center is different in a circumferential direction. 4. The vibrating member has a rod shape.
The cylindrical contact surface for the vibrating member is formed by the inner peripheral surface of the mass member by extrapolating the mass member to the vibrating member by making the mass member cylindrical or annular. 4. The vibration damping device for a vehicle according to any one of 3. 5. The vibrating member includes a vibrating member main body and a damping rod extending from the vibrating member main body and fixedly provided, and the mass member is externally provided with respect to the damping rod. The vehicle vibration damping device according to claim 4, which is inserted. 6. The vibration damping device for a vehicle according to claim 5, wherein the vibration member main body is an exhaust pipe of an internal combustion engine of an automobile. 7. A housing, which is formed integrally with or separate from the vibration member and into which vibration to be damped is inputted, is fixed to the vibration member, and a housing space is formed by the housing. The vehicle according to any one of claims 1 to 3, wherein the mass member is accommodated in the accommodation space to form a spherical or cylindrical contact surface with the housing by the outer peripheral surface of the mass member. Vibration control device. 8. The vehicle vibration damping device according to claim 1, wherein the mass member is formed using an elastic material as a main forming material. 9. The mass member is formed by using a metal material as a main forming material thereof, and a contact layer made of an elastic material is formed on the contact surface of the metal material. The vehicle vibration damping device according to any one of the above. 10. The vehicle vibration damping device according to claim 1, wherein a contact surface of at least one of the vibration member and the mass member has a Shore D hardness of 80 or less. 11. The mass of the simple substance in the mass member is 1
The vehicle vibration damping device according to any one of claims 1 to 10, wherein the weight is 0 to 1000 g. 12. The vehicle according to claim 1, wherein a maximum gap of 0.2 to 1.6 mm is formed between the contact surfaces of the vibration member and the mass member. Vibration control device. 13. The vibration damping device for a vehicle according to claim 1, wherein a total mass of the mass member is 5% to 10% of a mass of the vibration member.