JPS6274637A - Vibration damper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an i-position for damping vibrations, particularly vibrations associated with hη structural elements.

Attempts have been made to disrupt structural vibrations with viscoelastic materials, which are known to have high energy dissipation, ie, vibration disruption capabilities.

The main drawback of using viscoelastic damping materials alone is the quasi-elastic (qu
asielastic or quasiresill
ient) their low monocularity for structural materials exhibiting behavior.

To overcome this problem, stress-bearing or stress-constraining plates (
Stress constraint please
te) was added. These plates are usually made from rigid sheet metal, but more recently thinner and slightly more visible sheet metals and thermoplastics have been used.

Such prior art devices are disclosed in U.S. Pat.
No. 2, No. 1, No. 1, No. 1, No. 1, No. 1, September 1999, the damping efficiency of viscoelastic materials is said to be considerably enhanced by the addition of rigid, rigid constraint plates. The plates can be made from a variety of materials such as aluminum and other sheet metals, wood laminates, metal foils or thermoset plastic sheets.

These devices exhibit several undesirable properties, particularly when used against bendable or flexible structural elements. These properties include lack of orthotropy (orLl+oLropic property) in the constrained layer, unsatisfactory directional property (orLl + oLropic property), and
ty), unsatisfactory selectivity of rupture, inability to set stiffness and lack of mechanical linkage between the viscoelastic material and the top support layer. Furthermore, because the support material is made from sheet metal, prior art devices are heavy. They are also difficult and expensive to make properly.

The present invention relates to a vibration damping device having a lower elastic destructible layer attached to a structural element to be damped and an upper stress constraining layer attached to a viscoelastic layer opposite the structural element. Stress-bound layers exhibit the following properties: orthotropy, orientation of damping, selectivity of damping, configurable stiffness, mechanical linkage with the viscoelastic layer, and constraint of the viscoelastic layer.

The present invention overcomes the shortcomings of the prior art and provides a new vibration damping device.

The object of the invention is a vibration damping device having a lower viscoelastic layer and an upper stress-binding layer attached to a structural element to be damped, the upper stress-binding layer having a good stiffness and orthotropy, damping orientation and selectivity,
It is an object of the present invention to provide a vibration damping device that is a composite of stress constraining elements embedded within a damping material providing 8!1 mechanical linkage and restraint of a lower viscoelastic layer.

Another object of the invention is to provide at least each discrete or defined
It is an object of the present invention to provide a vibration damping device having an upper stress-constraining layer including stress-constraining elements made of one or more elongate elements interconnected or connected at points.

Another object is to provide a cloth-like (c1otb-11ke) stress flux element.

It is an object of the invention to provide a lightweight vibration damping device that is cheap and easy to manufacture.

Still other objectives include orthotropy, orientation of damping, selectivity of rupture, configurable stiffness, good mechanical linkage between the viscoelastic layer and the stress-constraining layer, and the ability to constrain the viscoelastic layer. An object of the present invention is to provide a vibration damping device having the following features.

Another object of the invention is to provide several sub-layers of different sterile materials, each having a monocularity different from the others.
ayer) to form a vibration damping device having a stress constraining layer.

Another object of the present invention is to provide a vibration damping device with a composite stress-constraining layer having elongated stress-constraining elements, each element made of different materials and exhibiting different stiffness moduli.

Another object is to provide a vibration damping device with better mechanical linkage between the viscoelastic layer and the constraint layer by using the same viscoelastic material in the upper stress constraint layer and the lower viscoelastic layer.

Another object is to provide a lightweight constraining layer that has properties similar to those of metal stress-bearing plates, but without the disadvantages of such metal plates.

Objects and advantages of the invention will become apparent from the following brief description of the drawings and claims.

Referring to the accompanying drawings, FIG. 2 shows a structural element 1 to be ruptured, a lower viscoelastic damping layer 2 attached to the structural element 1, and a lower viscoelastic damping layer 2 attached to the viscoelastic layer 2 on the side opposite the structural element 1. A prior art vibration damping device is shown comprising a top stress constraining layer 3 . Constraint N3 is formed from sheet metal or metal plate.

As mentioned above, this damping device is relatively heavy due to the use of a rigid, metal bundle layer. Moreover, this damping device exhibits unsatisfactory orthotropy, orientation and selectivity of disintegration, configurability of stiffness, and a closed linkage between the viscoelastic layer 2 and the eastern layer 3.

The manufacture of such prior art devices requires the use of specific tooling, and changing dimensions requires reworking of the material and often retooling.
It is difficult to require.

A preferred embodiment of the invention is shown in diagram m1.

The vibration damping device has a viscoelastic MIJ2. Its lower part is attached to the structural element 1 to be damped. The upper stress-constraining layer 30 is attached to the viscoelastic layer 2 on the opposite side of the structural element 1 . Upper restraint Jvi 30 is a composite consisting of stress restraint elements 32 embedded within a deformable material 34.

The binding element 32 is one or more #I long elements,
For example, 56.58. and 60 are interconnected or connected at least at certain or respective separating points, eg, 36 to 54.

The elongate elements, 56.58° and 60, are preferably formed from strands, fibers or tufts of fibers (II+I !i ll :i) of a mechanically resistant material having a high modulus of stiffness.

Stress constraining element 32, unlike prior art metal constraining layers,
It has excellent chromatic properties including, but not limited to, good orthotropy, chromatic orientation and selectivity, and stiffness configurability.

A preferred embodiment of the constraining element 32 is a fabric-like element made from one or more of the elongated elements described above, such as 56, 58 and 60.

Such cloth-like elements preferably include, for example:
It is a knitted 7 fabric such that element 56 is a knitted longitudinal element with transverse elements 58 and 60. The fabric-like constraining element may be woven or non-woven, or formed by other methods known in the textile art for making fabric-like elements.

In one embodiment of the invention, it is formed from a single elongated element such as commonly occurs in knitting.

In such embodiments, elongate element 56. of FIG.
58 and 60 are all the same elongate elements but are knitted or otherwise formed into a fabric-like element.

In another embodiment of the invention, the strip elements 56, 58, and 60 are separate elements forming a fabric-like element. The elongated elements 56, 58 and 60 are separate
te) and have different characteristics from others (distinc-L)
In some cases, it is preferred that the elongate elements 56, 58 and 60 are made from different materials having a different modulus than that of the others. This allows fabric-like elements to be formed with the exact stiffness required for a particular tearing job. Furthermore, the order of the different elongated elements can be varied to form a fabric-like element having different degrees of stiffness across or down its length. It allows creating a constraining layer with greater or lesser damping capacity at the edges or in the middle or in other parts, depending on the requirements of the structural element to be damped.

When the fabric-like element is in non-woven form, the bundles of elongated elements are bonded to each other at points in contact by adhesives, cutting or other means conventionally used to form non-woven elements. Preferably, it is formed from a lattice of bundles of elongate elements connected to each other.

Preferably, the elongate element has a diameter of about 6000 to 660.0
Made from mechanically resistant material with a modulus of 00 MPa. Examples of such materials include non-metallic or metallic materials or mixtures thereof, such as glass fibres, nylon and other organic fibres, as well as metal fibres, or strands or wires, which are braided or braided. These include, but are not limited to, no.

The dimensions of the elongated element can vary depending primarily on the stiffness, thickness, weight and degree of damping as well as the dimensional requirements of the damping device.

When the elongate elements are formed into fabric-like elements, they can be curled or stretched as commonly taught in the textile art.

Constraining element 32 is embedded within damping material 34.

The damping material 34 exhibits damping properties between -50°C and +250°C and preferably has a temperature of about 0°1 to about 5000 MPa.
It can be any material with a monocularity of u.

Damping material 34 may be cured or uncured.
cured) elastomeric materials, thermoset polymers and copolymers, thermoplastic polymers and copolymers, or mixtures thereof. Examples of such materials useful in the present invention include natural rubber, nitrile polymers, polychloroprene polymers, butyl polymers, silicone polymers, polybutadiene polymers, polyethylene polymers, polyvinyl chloride polymers, epoxy resins, cured or uncured; Included are, but are not limited to, phenol fl (Iltt), polyimides, polyesters, and copolymers, derivatives, or mixtures thereof.

500 if thermosetting resins or polymers are used.
Preferably, it can be used as a damping material at temperatures as low as 0.degree.

Of course, any mixture of vulcanized or unvulcanized materials and/or
or thermosetting with any of the thermoplastics (
It can be made of the materials listed above, including mixtures of fats.

In one aspect of the invention, damping material 34 can be made from the same viscoelastic material as in viscoelastic layer 2 and can be connected or attached to viscoelastic layer 2 by means known in the art. . Preferably, the damping material 34 and the viscoelastic layer 2 of the top i30 are formed simultaneously or sequentially and finished together into the final damping device. It has been found that improved adhesion, ie, mechanical linkage, of the top layer 30 to the viscoelastic layer 2 is obtained by forming the layers simultaneously or sequentially using the same viscoelastic material.

Alternatively, the damping material 34 of the top layer 30 may be formed from several sublayers of different damping materials, each having a different modulus to provide varying degrees of despondency.

Constraining elements 32 can be embedded within one or more flq layers depending on the relative thicknesses of elements 32 and sublayers.

Furthermore, if it is necessary to obtain a desired degree of attenuation,
More than one top layer 30 can be used in the present invention. The additional top layer can be attached or connected by conventional means such as adhesives or by using the same damping material as in the first top layer and finishing them at the same time.

The damping device can be formed in situ on the structural element to be damped, or it can be made separately and then attached to the structural element by mechanical means, such as glue or rivets, or by chemical means, such as adhesives. I can do it. The means of attaching the damping device to the structural element are not particularly important, as long as the means do not interfere with the damping characteristics of the device and reliably retain the damping device on the structural element.

The Honjo Jaku device provides excellent damping characteristics and is lightweight and inexpensive.
rtia terms) and attenuation ￥C
An important out-of-phase term (out
It is thought that the addition of ``of phase Lerm'' gives a annihilation effect.

The damping device can be applied to any structural element, but most preferably to extra-wall or elastic properties (quasielas).
Lic or resilienL property
es) can be used in the structure element indicating
Examples of structures in which the present damping device can be used include beams or supports, architectural components such as wall, floor or ceiling panels, body panels and other components in automobiles, aircraft or ships, two-circuit plates, skis, etc. sports equipment such as
Machinery such as, but not limited to, high speed offset inking rollers is included.

Although the invention has been described with respect to its preferred embodiments, other embodiments can achieve the same results. Changes and modifications in this invention will be apparent to those skilled in the art and are intended to cover in the appended claims all such modifications, changes and equivalents that are within the spirit and scope of the invention.

[Brief explanation of drawings]

- FIG. 1 is a side sectional view of a damping device according to a preferred embodiment of the present invention. FIG. 2 is a side cross-sectional view of a prior art damping device. In the figure, 1...structural elements, 2. elastic elements, 8.
60...Elongated element.

Claims (1)

Claims: 1. A lower damping viscoelastic layer made of a damping viscoelastic material attached to the surface of the structural element to be damped, and located above the viscoelastic layer on the opposite side of the structural element. a damping device, in particular for damping vibrations relating to a structural element, characterized in that the upper layer is a composite stress-constraining layer with stress-constraining elements embedded within the damping material. vibration damping device. 2. the stress constraining element is formed from one or more elongate elements of mechanically resistant material, the elongate elements being interconnected or connected at least at certain or discrete points; A vibration damping device according to claim 1. 3. The vibration damping device of claim 2, wherein said elongate element is selected from the group consisting of strands, fibers and tufts of fibers. 4. The vibration damping device of claim 2, wherein the stress constraining element is formed from one continuous elongated element. 5. The stress constraining element is selected from the group consisting of strands, fibers and tufts of fibers and is comprised of a mechanically resistant material.
2. A vibration damping device according to claim 1, wherein the vibration damping device is a fabric-like element made of one or more elongated elements. 6. The vibration damping device according to claim 5, wherein the cloth-like element is knitted. 7. The vibration damping device according to claim 5, wherein the cloth-like element is woven. 8. A vibration damping device according to claim 5, wherein said cloth-like element is not woven. 9. A vibration damping device according to claim 8, wherein said non-woven element comprises a lattice of bundles of strands interconnected by welding, adhesive or thermal bonding. 3. The damping device of claim 2, wherein the modulus of the one or more elongated elements is between about 6,000 MPa and 660,000 MPa. 11. Claim 1, wherein the damping material of the top stress confinement layer has damping properties over a temperature range of about -50°C to +250°C and has a modulus of about 0.1 MPa to about 5000 MPa. Vibration damping device as described. 12. The vibration damping device of claim 1, wherein the damping material is selected from the group consisting of elastomeric materials, thermosetting polymers, thermoplastic polymers, and mixtures thereof. 13. The damping material has several sublayers.
), the sublayers comprising different damping materials having different damping properties or capacities. 14. The vibration damping device of claim 1, wherein the stress constraining element is made from one or more non-metallic elongate elements. 15. The vibration damping device of claim 1, wherein the stress bearing element is made from one or more elongated metallic elements. 16. Vibration damping device according to claim 2, wherein the stress-bearing element can be calendered and/or stretched. 17. The vibration damping device of claim 1, wherein the damping materials of the viscoelastic layer and the stress bearing layer are made from the same material. 18. The vibration damping device of claim 2, wherein the stress constraining layer is formed from a number of elongate elements, each having a different modulus of stiffness.