JP3560140B2 - Damping device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vibration damping device that prevents vibration generated in a vibration transmitting member such as various functional members and a frame.
[0002]
[Prior art]
For example, in a vehicle such as an automobile, vibration of a power source such as an internal combustion engine, vibration from a running road surface or the like is transmitted to the entire vehicle body, and vibration transmission members such as various functional devices attached to the vehicle body frame resonate. Then, the function is reduced and noise is generated.
[0003]
Therefore, a vibration transmitted to the vibration transmitting member is suppressed by attaching a mass damper, a dynamic damper, a vibration damper, or the like to the normal vibration transmitting member.
[0004]
However, the mass damper changes the natural frequency by adding a weight to the vibration transmitting member, but it is necessary to increase the weight of the weight in order to obtain a sufficient vibration reduction effect. Will increase.
[0005]
The dynamic damper is not effective for vibration having a plurality of resonance frequencies because a vibration frequency that can be damped is specified by the spring constant of the elastic body and the weight of the weight.
[0006]
Further, the vibration damping material is a single-layer or multi-layer sheet-like elastic member adhered to a plate-like vibration transmission member, but it has no effect unless it is adhered to a certain large area, and the vibration damping effect is not affected by temperature. And the vibration damping effect may be reduced depending on the temperature.
[0007]
Therefore, in the invention previously filed (International Application No. PCT / JP98 / 05530), at least a part of a filler made of an elastic material is inserted non-adhesively with a gap in an internal space of a housing fixed to the vibration transmitting member. With the structure, the damping of the vibration is exhibited based on the sliding friction when the filler material comes into contact with the inner surface of the housing and the energy loss due to the collision, so that it is effective even for a plurality of resonances with different frequencies. A damping effect can be obtained.
Vibration damping due to sliding friction and energy loss due to collision is less affected by temperature.
[0008]
[Problems to be solved by the invention]
Since the vibration damping effect is obtained based on the sliding friction when the filler abuts against the inner surface of the housing and the energy loss due to the collision, the effect increases as the speed of the collision of the filler with the inner surface of the housing increases, and the vibration frequency, in particular, increases. , A vibration damping effect can be obtained in a resonance region having a high value.
[0009]
Therefore, the vibration damping effect cannot be expected much at the low resonance frequency.
It is also not effective when it is necessary to obtain a vibration damping effect for a plurality of resonances and to attenuate vibrations of a specific frequency particularly significantly.
[0010]
The present invention has been made in view of such a point, and an object thereof is to obtain a vibration damping effect for a plurality of resonances in a wide frequency range and to attenuate vibration of a specific frequency, thereby reducing temperature dependency. The point is to provide a vibration damping device.
[0011]
Means for Solving the Problems and Functions and Effects
In order to achieve the above object, an invention according to claim 1 includes a housing having an internal space and formed of a rigid material and fixed to a vibration transmitting member, and a housing in the internal space of the housing in a vibration direction of the housing. An elastic body inserted in a non-adhesive manner with a gap therebetween, and a weight integrally supported by the elastic body so as not to touch the housing, the housing and the elastic body include: elastic body impact damper obtaining a damping effect of the vibration is formed on the basis of the energy losses due to sliding friction and collision when colliding with the inner surface of the housing, the dynamic damper is formed between the elastic member and the weight, the The elastic body is provided by a dynamic damper so that a vibration damping effect of a specific frequency, which cannot be obtained by the impact damper, can be obtained. Spring constant and the mass of the weight is a vibration damping device that is set.
[0012]
When the elastic body collides with the inner surface of the housing, the impact damper has a structure in which the elastic body is inserted in a non-adhesive manner with a gap in the vibration direction of the housing in the internal space of the housing fixed to the vibration transmitting member with a gap in the vibration direction of the housing. Since the damping property is obtained based on the energy loss due to the sliding friction and the collision, the vibration damping effect can be obtained even for a plurality of resonances having different frequencies, and the temperature dependency is small.
[0013]
For the resonance of the particular frequency can not be obtained vibration damping effect by impact damper, the mass of the spring constant and weight of the elastic body in the dynamic damper to provide a weight which is integrally supported on the elastic body so as not to touch the housing The vibration damping effect can be obtained for a plurality of resonances in a wide frequency range by combining the impact damper and the dynamic damper .
[0018]
According to a second aspect of the present invention, in the vibration damping device according to the first aspect, the specific frequency vibration is lower than a frequency at which a vibration damping effect is obtained by the impact damper .
[0019]
The impact damper is based on energy loss due to sliding friction and collision, and therefore has a large vibration damping effect particularly in a resonance region where the vibration frequency is high.
[0020]
Therefore For the resonance of the frequency lower than the frequency to be obtained vibration damping effect by impact dampers, to obtain a more damping effect dynamic damper over a number of resonance peak levels in substantially the entire frequency range ranging from low frequency to high frequency Can be reduced .
[0021]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment according to the present invention will be described below with reference to FIGS.
This embodiment relates to a main vibration system in which a vibration transmission member 2 such as an engine unit, accessories, intake / exhaust pipes, a subframe, a body panel, an arm or a bracket is attached to a vibration source 1 such as a body frame of an automobile. This vibration damping device 10 is provided on the vibration transmitting member 2 as a sub-vibration system, and a schematic diagram thereof is shown in FIG.
[0022]
In this vibration damping device 10, a columnar elastic body 12 is inserted into a cylindrical housing 11 in a non-bonded manner with a slight gap.
A weight (mass m) 13 is embedded in the elastic body 12.
[0023]
The housing 11 of such a sub-vibration system is integrally fixed to the vibration transmission member (mass M) 2 of the main vibration system.
The direction in which the vibration transmitting member 2 vibrates is the direction indicated by the left-right arrow in FIG. 1, and the gap d between the housing 11 and the elastic body 12 is provided in the same vibration direction.
[0024]
The housing 11 may be formed of a rigid material, and may be any shape as long as the elastic body 12 can be inserted into the internal space with a gap d in the vibration direction with respect to the vibration direction. In addition, a structure is required in which the inserted elastic body 12 is sealed so as not to fall off.
[0025]
The elastic body 12 is formed of rubber or resin or an elastic foam containing the same as a main component, and is suitably made of high specific gravity rubber or the like. The surface has a smooth flat surface or a curved surface, but has an uneven shape. It may be.
The elastic body 12 has a predetermined spring constant k.
[0026]
The weight 13 embedded inside the elastic body 12 is made of steel and has a predetermined mass m.
The material of the weight 13 is not limited to steel, and various materials having a high density can be considered.
[0027]
In the sub-vibration system having the above-described structure, a damper (hereinafter referred to as an impact damper) in which the elastic body 12 is inserted in a non-adhesive manner with a gap d in the vibration direction inside the housing 11 and the elastic body 12 And a dynamic damper in which a weight 13 having a mass m is embedded.
[0028]
A diagram modeling the main vibration system and the impact damper is shown in FIG. 2A, and a diagram modeling the main vibration system and the dynamic damper is shown in FIG. 2B.
[0029]
Referring to (1) of FIG. 2, in the impact damper, the elastic body 12 inserted with a gap d in the internal space with respect to the vibration of the housing 11 integrated with the vibration transmitting member 2 It relatively moves and collides with the inner surface of the housing 11.
[0030]
The vibration damping effect is obtained based on the sliding friction when the elastic body 12 collides with the inner surface of the housing 11 and the energy loss due to the collision.
FIG. 3 shows a vibration transmission characteristic of the vibration transmission member 2.
[0031]
In FIG. 3, a broken line {circle around (1)} indicates a vibration transmission characteristic when no vibration damping device is provided, and prominent peaks appear at many resonance frequencies from a low frequency region to a high frequency region.
[0032]
The dashed-dotted line (2) indicates the vibration transmission characteristics in the case where the impact damper is provided. Compared with the dashed line (1), the prominent peak levels at a plurality of resonance frequencies are substantially suppressed. In particular, the resonance peak level on the high frequency side is greatly reduced.
[0033]
This is because the impact damper is based on energy loss due to sliding friction and collision, so that the higher the collision speed of the elastic body 12 against the inner surface of the housing 11, the greater the vibration damping effect, and thus the vibration damping effect particularly in the resonance region where the vibration frequency is high. Is large.
[0034]
On the other hand, the resonance peak level around 80 Hz of the low frequency is not reduced, but rather is increased.
Therefore, the present vibration damping device 1 includes a dynamic damper in addition to the impact damper.
[0035]
As shown in FIG. 2 (2), a weight 13 having a mass m is connected to a housing 11 integral with the vibration transmitting member 2 via an elastic body 12 having a spring constant k to constitute a dynamic damper.
[0036]
The mass m of the weight 13 and the spring constant k of the elastic body 12 are set so as to particularly obtain a vibration damping effect at about 80 Hz in a low frequency region.
That is, the natural frequency of the sub-vibration system is set to match the natural frequency of the main vibration system.
[0037]
Then, referring to FIG. 3, the solid line (3) indicates that the vibration transmission characteristic obtained by the impact damper and indicated by the dashed-dotted line (2) and having a particularly high resonance peak level at around 80 Hz was particularly prominent. So that it is greatly reduced.
The other frequencies are almost the same and have the same characteristics as shown by the dashed line (2).
[0038]
Therefore, the present vibration damping device 1 allows the impact damper and the dynamic damper to coexist so as to compensate for each other's disadvantages, and can reduce a number of resonance peak levels in almost all frequency ranges from low frequencies to high frequencies.
Since vibrations at a number of resonance frequencies can be reduced, it is possible to prevent the function of the vibration transmission member 2 from deteriorating and to prevent noise.
[0039]
The impact damper reduces the plurality of resonance peak levels based on the energy loss due to sliding friction and collision, so that the impact damper is hardly affected by the temperature, and the damping effect is not reduced by the temperature.
[0040]
After damping the vibrations with respect to the plurality of resonances by the impact damper, it may be necessary to further reduce the vibrations for a more specific resonance frequency among the damped resonances, but even in such a case. The dynamic damper can further reduce resonance at a required frequency, and can be applied to various uses.
[0041]
Since the weight 13 is buried inside the elastic body 12 of the impact damper, the effect as a dynamic damper can be provided at the same time, so that the structure is simple and the size and cost can be reduced.
[0042]
Next, a schematic diagram of a vibration damping device 20 according to another embodiment will be described with reference to FIG.
A pair of elastic bodies 22 and 23 and a weight 24 supported by the elastic bodies 22 and 23 are inserted into a cylindrical housing 21 integrally attached to the vibration transmitting member.
[0043]
The pair of elastic bodies 22 and 23 has a cylindrical shape having an outer diameter slightly smaller than the inner diameter of the cylinder of the housing 21, and a support portion extending from the opposing surfaces of the elastic bodies 22 and 23 arranged coaxially with the central axis. The tips of 22a and 23a are baked on the center weight 24, and the weight 24 is integrally fixed and supported by the elastic bodies 22 and 23 on both sides.
[0044]
The weight 24 has a columnar shape having an outer diameter smaller than the outer diameter of the elastic bodies 22 and 23, and has a central axis coaxial with the elastic bodies 22 and 23. The weight 24 is elastically supported by the elastic members 22 and 23 on both sides without touching the housing 21.
[0045]
Note that a space is secured between the inner surface of the housing 21 and the weight 24 so that the weight 24 that is elastically supported does not touch the housing 21 even if the weight 24 is displaced relative to the elastic bodies 22 and 23. .
[0046]
As described above, the vibration damping device 20 constitutes an impact damper in which the elastic bodies 22 and 23 are inserted in a non-adhesive manner in the housing 21 with a gap in the vibration direction indicated by the arrow in FIG. The weight 24 constitutes a dynamic damper elastically supported by the elastic bodies 22 and 23.
[0047]
Therefore, the impact damper attenuates vibrations for a plurality of resonances and the dynamic damper attenuates vibrations that cannot be attenuated, thereby lowering a number of resonance peak levels in almost all frequency ranges from low frequencies to high frequencies. it can.
[0048]
Further, after a plurality of resonances are damped by the impact damper, further vibration damping can be performed for a specific resonance frequency among the damped resonances.
[0049]
In addition, the housing of the vibration damping device can be provided integrally with the vibration transmitting member by being fixed to the vibration transmitting member by welding or the like, screwing it with screws, etc., or attaching it with a special mounting tool. A housing may be formed.
[0050]
Further, in a case where the vibration transmitting member has a cylindrical shape or the like and has an internal space such as a suspension arm, the vibration transmitting member itself may be used as a housing, and an elastic body may be inserted with a gap therein. .
[0051]
INDUSTRIAL APPLICABILITY The present invention is applicable to various types of vibration transmitting members to which vibration is transmitted from a vibration source, in addition to vehicles such as automobiles and trains.
[Brief description of the drawings]
FIG. 1 is a schematic view of a structure in which a vibration transmitting member includes a vibration damping device according to an embodiment of the present invention.
FIG. 2 is a diagram modeling a main vibration system and a damper structure.
FIG. 3 is a diagram showing a vibration transmission characteristic.
FIG. 4 is a schematic diagram of a vibration damping device according to another embodiment.
[Explanation of symbols]
1: Vibration source, 2: Vibration transmitting member,
10: Vibration control device, 11: Housing, 12: Elastic body, 13: Weight,
20: vibration damping device, 21: housing, 22, 23: elastic body, 24: weight.

Claims (2)

A housing having an internal space and formed of a rigid material and fixed to the vibration transmitting member,
An elastic body inserted into the internal space of the housing in a non-adhesive manner with a gap in the vibration direction of the housing,
A weight which is integrally supported by the elastic body so as not to touch the housing,
The housing and the elastic body form an impact damper that obtains a vibration damping effect based on sliding friction when the elastic body collides with an inner surface of the housing and energy loss due to the collision,
Forming a dynamic damper with the elastic body and the weight,
By the dynamic damper, the spring constant of the elastic body and the mass of the weight are set so that a vibration damping effect of a specific frequency, which is not obtained by the impact damper, can be obtained. Characteristic damping device. The specific frequency, vibration damping device according to claim 1, wherein a lower than the frequency to be obtained vibration damping effect by the impact damper.

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