DE112015005173T5 - Vibration-damping molded product of fiber-reinforced resin and motor vehicle component, in which this is used - Google Patents

Abstract

There is provided a vibration damping molded product of fiber reinforced resin of a laminate comprising layers of fiber reinforced resin each comprising a resin impregnated fabric and vibration damping layers of a synthetic resin. The vibration damping layers include upper and lower vibration damping layers. The fiber-reinforced resin layers comprise a fiber-reinforced resin central layer located between the upper and lower vibration-damping layers at a center position with respect to a thickness direction of the laminate, and fiber-reinforced resin outer layers extending outward from the upper and lower vibration-damping layers, respectively Layers are provided. A distance (X) from a central laminate plane defined with respect to the thickness direction of the laminate to an interface between the central layer of fiber reinforced resin and each of the upper and lower vibration damping layers and a distance (Y) from the central laminate plane to each of opposite surfaces of the laminate meet the relationship X / Y = 0.19 to 0.89. The total thickness (d) of all the vibration damping layers of the laminate and the thickness (D) of the laminate satisfy the relationship d / D = 0.02 to 0.18. Therefore, the fiber-reinforced resin vibration damping molded product of the present invention has higher strength and excellent vibration damping properties. Further, there is provided a motor vehicle component including the vibration damping molded product of fiber reinforced resin as its component.

Description

TECHNICAL AREA

The present disclosure relates to a fiber-reinforced resin vibration damping molded product which is a fiber reinforced resin molded product obtained by combining fibers such as fibers. As carbon fibers or glass fibers, has been imparted with a resin improved strength, and further been given vibration damping properties, and a motor vehicle component comprising the vibration damping molded product of fiber reinforced resin as its component.

STATE OF THE ART

Conventionally, metals, such as. As iron and aluminum, as materials for motor vehicle components, such as. As a torsion bar or a torsion spring and a handlebar, used for strength and heat resistance. Furthermore, fiber-reinforced resins (FRP) obtained by combining fibers such as e.g. As glass fibers or carbon fibers, reinforced with a resin, comparable to the metals strength and yet a low weight. Therefore, the fiber-reinforced resins are promising materials as an alternative to metals (see PTL 1, PTL 2, and the like).

DOCUMENTS OF THE PRIOR ART

PATENT DOCUMENTS

• PTL 1: JP 2013-108194 A
• PTL 2: JP 2008-265108 A
• PTL 3: JP 5373667 B
• PTL 4: JP 3772216 B

SUMMARY OF THE INVENTION

The FRP has excellent strength, but its flexural ductility is inferior to that of the metals. Therefore, the FRP can not be used as a material for a handlebar and other components that tend to cause a serious accident when it breaks.

Motor vehicle components must often have vibration-damping properties in addition to the strength. However, there has been no suggestion of imparting vibration damping properties to a metal or FRP automotive component. Under these circumstances, in recent years, techniques for improving the vibration damping properties have been provided by providing a vibration damping layer, such as a vibration damping layer. Example, a rubber layer or an elastomer layer, between FRP layers, each having a fibrous filler such. As carbon fibers or glass fibers, proposed (see PTL 3 and PTL 4), although these were not automotive components. Even if these techniques for the automotive components, such. As a handlebar, are applied, however, it is impossible to give the motor vehicle components a desired strength. In this regard, an improvement is required.

In view of the above, it is an object to provide a vibration damping molded product of fiber reinforced resin having higher strength and excellent vibration damping properties, and to provide a motor vehicle component comprising the vibration damping molded product of fiber reinforced resin as its component.

According to a first aspect of the present invention for achieving the object, a fiber-reinforced resin vibration-damping molded product made of a laminate comprising fiber-reinforced resin layers each comprising a resin-impregnated fabric and vibration-damping synthetic resin layers, wherein the vibration-damping layers upper and lower vibration-damping layers, wherein the fiber-reinforced resin layers comprise a fiber-reinforced resin central layer located between the upper and lower vibration-damping layers at a center position with respect to a thickness direction of the laminate, and outer layers of fiber-reinforced resin each out of the upper and lower wherein the laminate has a central laminate plane with respect to the thickness direction thereof, a distance (X) from the central laminate plane to an interface between the central layer of fiber reinforced resin and each of the upper and lower vibration damping layers and a distance (Y) from the central laminate plane to each of opposite surfaces of the laminate satisfy the relationship X / Y = 0.19 to 0.89, wherein the total thickness (d) of all the vibration damping layers of the laminate and the thickness (D) of the laminate is the relationship d / D = 0.02 to 0.18. According to a second aspect of the present invention, there is provided a motor vehicle component comprising the fiber-reinforced resin vibration damping molded product according to the first aspect as the component thereof, wherein the motor vehicle component is a torsion bar or a torsion spring, a handlebar, a lower arm, a strut, a propeller shaft, an impact beam , a stabilizer, a subframe or subframe or axle, a bumper or a side door support is.

The inventors have intensively studied to solve the above-mentioned problems. In the studies, the inventors have tried to produce a laminate comprising a layer of fiber reinforced resin formed by impregnating a fabric with a resin and a vibration damping layer of a synthetic resin for strength and the like, and have by manufacturing carried out prototypes different experiments. As a result, the inventors have found that the thickness of the vibration-damping layer and the laminate structure significantly affect the vibration-damping properties, strength, rigidity and other characteristic properties of the laminate. Further, the inventors have found that, when a fiber reinforced resin (fiber reinforced resin) layer is provided between upper and lower vibration damping layers at a center position with respect to the thickness direction of the laminate, and further, fiber reinforced resin layers are provided outward from the upper and lower and a distance (X) from a central laminate plane defined in the thickness direction of the laminate to an interface between the fiber-reinforced resin central layer and each of the upper and lower vibration-damping layers and a distance (Y ) from the central laminate plane to each of opposite surfaces of the laminate satisfy the relationship X / Y = 0.19 to 0.89, and the total thickness (d) of all the vibration damping layers of the laminate and the thickness (D) of the laminate satisfy the relation d / D = 0.02 to 0.18 meet the laminate excellent vibration damping properties can be imparted without affecting the strength and rigidity of the laminate, and have achieved the above-mentioned object. In this way, the inventors have obtained the present disclosure.

As described above, the fiber-reinforced resin vibration damping molded product according to the present disclosure is a laminate comprising fiber reinforced resin layers each comprising a resin impregnated fabric and vibration damping synthetic resin layers. The vibration damping layers include upper and lower vibration damping layers. The fiber-reinforced resin layers comprise a fiber-reinforced resin central layer located between the upper and lower vibration-damping layers at a center position with respect to a thickness direction of the laminate, and fiber-reinforced resin outer layers extending outward from the upper and lower vibration-damping layers, respectively Layers are provided. The laminate has a central laminate plane with respect to its thickness direction. A distance (X) from the central laminate plane to an interface between the fiber-reinforced resin central layer and each of the upper and lower vibration-damping layers and a distance (Y) from the central laminate plane to each of opposite surfaces of the laminate satisfy the relation X / Y = 0.19 to 0.89. The total thickness (d) of all the vibration damping layers of the laminate and the thickness (D) of the laminate satisfy the relationship d / D = 0.02 to 0.18. Therefore, the fiber-reinforced resin vibration damping molded product of the present invention has excellent strength, rigidity, and excellent vibration damping properties, and is better than the ordinary FRP in bending ductility, fatigue resistance, and heat resistance. Thus, the fiber-reinforced resin vibration damping molded product of the present invention can be advantageously used in a field of application such as. B. automotive components are used.

In particular, when the synthetic resin for the vibration-damping layers is a polyamide resin and the resin for the fiber-reinforced resin layers is an epoxy resin, the inter-layer adhesion between the vibration-damping layers and the fiber-reinforced resin layers is improved.

When the vibration-damping layers each comprise a synthetic-resin fabric, the inter-layer adhesion is stronger.

When the fiber-reinforced resin central layer comprises a laminate comprising a plurality of fiber-reinforced resin layers, the thickness of the fiber-reinforced resin central layer can be more easily adjusted.

When the thickness (D) of the laminate is 1.9 to 7.4 mm, the formability of the laminate is improved.

When the vibration damping layers each have a thickness of 0.04 to 0.4 mm, the vibration damping molded product made of fiber reinforced resin has excellent vibration damping properties and excellent flexural strength.

When the fabric is a twill weave, plain weave, or satin weave of a continuous filament selected from a carbon filament, a glass filament, an aramid filament, and a basalt filament, the fabric has an excellent reinforcing effect and the like.

When the resin for the fiber reinforced resin layers contains at least one inorganic material selected from the group consisting of potassium titanium oxide, aluminum oxide, zinc oxide and titanium oxide, the fiber reinforced resin layers are even better in strength and stiffness improving effect.

The vibration damping molded product of fiber reinforced resin according to the present disclosure having the above effects can be advantageously used as a component of a torsion bar or a torsion spring, a handlebar, a lower arm, a strut, a propeller shaft, an impact beam, a stabilizer, a subframe or subframe or axle carrier, a bumper, a side door support or other motor vehicle part are used. Further, the fiber-reinforced resin vibration damping molded product according to the present disclosure may be provided in a sheet shape and provided with a predetermined shape.

BRIEF DESCRIPTION OF THE DRAWING

1 FIG. 10 is a schematic diagram showing a section of an exemplary molded product of fiber reinforced resin according to the present disclosure. FIG.

DESCRIPTION OF EMBODIMENTS

Next, embodiments of the present disclosure will be described.

A vibration damping molded product of fiber reinforced resin according to the present disclosure is a laminate comprising layers of fiber reinforced resin, each comprising a resin impregnated fabric, and vibration damping layers of a synthetic resin. The vibration damping layers include upper and lower vibration damping layers. The fiber-reinforced resin layers comprise a fiber-reinforced resin central layer located between the upper and lower vibration-damping layers at a center position with respect to a thickness direction of the laminate, and fiber-reinforced resin outer layers extending outward from the upper and lower vibration-damping layers, respectively Layers are provided. The laminate has a central laminate plane with respect to the thickness direction of the laminate. A distance (X) from the central laminate plane to an interface between the fiber-reinforced resin central layer and each of the upper and lower vibration-damping layers and a distance (Y) from the central laminate plane to each of opposite surfaces of the laminate satisfy the relation X / Y = 0.19 to 0.89. The total thickness (d) of all the vibration damping layers of the laminate and the thickness (D) of the laminate satisfy the relationship d / D = 0.02 to 0.18. For ensuring both the bending strength and the vibration damping properties, the relationship X / Y is preferably X / Y = 0.23 to 0.69, and the relationship d / D is preferably d / D = 0.03 to 0.08.

In the present disclosure, the term "central laminate plane" means a central plane that is set with respect to the thickness direction of the laminate, regardless of whether the central plane coincides with an actual surface of a layer (an interface between layers) Not. If the fiber reinforced resin central layer in the present disclosure comprises only one layer of fiber reinforced resin, the fiber reinforced resin central layer may be the only layer of fiber reinforced resin, but preferably it may comprise a plurality of layers fiber reinforced resin. With this arrangement, the fiber-reinforced resin central layer can be formed more easily in a desired thickness, and resin impregnation is facilitated.

The 1 FIG. 12 is a schematic diagram showing a section of an exemplary fiber-reinforced resin vibration damping molded product according to the present disclosure (according to Example 1 described later). FIG. The reference number 1 denotes the fiber reinforced resin layers and the reference numeral 2 refers to the vibration damping layers. In the 1 The central layer of fiber reinforced resin is shown as having two layers of fiber reinforced resin 1 includes. In the 1 is the distance from the central laminate plane to the interface between the fiber-reinforced resin central layer and each of the vibration-damping layers 2 represented by the reference letter X and the distance from the central laminate plane to each of the opposite surfaces of the laminate is indicated by the reference letter Y. In the present disclosure, the laminate is as disclosed in U.S. Patent Nos. 5,416,666, 4,648,866, 5,648,859, 5,648,866, and 5,657,855 1 for the vibration damping characteristics and the like is preferably formed so as to be vertically symmetric with respect to the central laminate plane. In the present disclosure, the structure of the laminate is not limited to the vertically symmetrical structure, but may be an asymmetric structure as long as the relationships X / Y and d / D described above are satisfied. In the 1 is just a vibration-damping layer 2 however, two or more vibration damping layers may be provided between the central laminate plane and each of the opposing surfaces of the laminate below or above the central laminate plane, however, two or more vibration damping layers may be provided between the central laminate plane and each of the opposing surfaces of the laminate. In this case, the distance X is set as a distance from the central laminate plane to an interface between the fiber-reinforced resin central layer and one of the vibration-damping layers which is closest to the central laminate plane. As it is in the 1 is shown, the laminate comprises two vibration damping layers 2 and therefore the total thickness d is the total thickness of these two vibration damping layers.

In the present disclosure, as shown in the 1 It can be seen that the thickness D and the distance Y of the relationship D = 2Y. In the present disclosure, the thickness D of the fiber-reinforced resin vibration damping molded product is preferably 1.9 to 7.4 mm, more preferably 2.0 to 3.0 mm from the viewpoint of moldability. The vibration damping layers each have a thickness of 0.04 to 0.4 mm, more preferably 0.12 to 0.2 mm in view of vibration damping properties, flexural strength and the like.

In the present disclosure, the shape of the vibration damping molded product of fiber reinforced resin is not the same as in FIG 1 and the vibration damping molded product of fiber reinforced resin can be given a desired shape by a compression molding method or the like. Even in this case, the above relationships set for the laminate structure according to the present disclosure should be satisfied.

In the present disclosure, the fiber-reinforced resin layers of the fiber-reinforced resin vibration damping molded product are each formed by impregnating the fabric with the resin as described above. The fabric may be a fabric composed of a continuous filament, such. A carbon filament, a glass filament, an aramid filament or a basalt filament, woven through a twill weave, a plain weave or a satin weave, or a fabric partially comprising a unidirectional filament assembly portion (unidirectional filament portion). In particular, in terms of strength and fatigue resistance, the fabric is preferably a fabric applied to the molded product at various angles (in various directions), woven fabric woven from the carbon filament, and cost-effective which is woven from a glass filament. The fabric is preferably a 2 to 20 m wide fabric woven from 1000 to 24000 continuous filaments each having a filament diameter of 5 to 7 μm. The fabric preferably has a weight of 61 to 200 g / m ² and a thickness of 0.085 to 0.25 mm for a reinforcing effect.

As the resin for impregnating the fabric, a thermoplastic resin or a thermosetting resin is used.

Examples of the thermoplastic resin include polyamide resins, polyolefin resins, acrylonitrile-butadiene-styrene resins, polyester resins, polycarbonate resins, polystyrene resins, polyacetal resins, modified polyphenylene ether resins, polyphenylene sulfide resins, polyetherimide resins, polyetheretherketone resins, polyethersulfone resins and thermoplastic elastomers, which may be used alone or in combination.

Examples of the thermosetting resins include epoxy resins, unsaturated polyester resins, vinyl ester resins, and phenolic resins, which may be used alone or in combination.

An inorganic material, such as. Talc, silica, carbon black, titanium oxide, zinc oxide, potassium titanium oxide or alumina may be added to the resin to improve strength and rigidity and to prevent contraction (depression or warping). Specifically, an inorganic material having a Mohs hardness of not less than 4 is added to the resin to improve the strength and rigidity. Specific examples of such an inorganic material include potassium titanium oxide, aluminum oxide, zinc oxide and titanium oxide. The Mohs hardness is measured by a Mohs hardness meter (available from Tokyoscience Co., Ltd.). The proportion of the inorganic material to be added to the resin is preferably 1 to 15 parts by weight, more preferably 5 to 10 parts by weight, based on 100 parts by weight of the resin for improving the strength and rigidity. The resin is preferably kneaded by means of three rolls, a kneader, a Banbury mixer or the like, more preferably by means of the rolls in view of the processability.

The fiber-reinforced resin layers each containing the inorganic material in this way enable the vibration damping molded product of fiber reinforced resin to be given a higher flexural modulus and thus higher impact resistance and higher energy absorbing capacity.

The impregnation of the fabric with the thermosetting resin can be accomplished by a hand lay-up molding process. The impregnation of the fabric with the thermoplastic resin can be accomplished by laminating or stacking the fabric and a layer of the thermoplastic resin and hot pressing the resulting stack to melt the thermoplastic resin layer. In the hand lay-up molding method, the fabric is impregnated with a solution of the resin by applying the resin solution to the fabric, dipping the fabric in the resin solution, or uniformly distributing the resin solution on the fabric by a roller or the like.

In the present disclosure, the vibration damping layers of the fiber-reinforced resin vibration damping molded product are synthetic resin layers each made of a thermoplastic resin or a thermosetting resin. Since the vibration damping layers each need to have vibration damping properties, the resin preferably has a tan δ of not less than 0.03 at 25 ° C. In particular, an alloy material prepared by alloying polyamide 6 or polyamide 12 with polypropylene is preferable for improving the vibration damping properties.

In the present disclosure, it is preferable that the vibration damping layers in the fiber-reinforced resin vibration damping molded product are each made of the polyamide resin (or the alloy material of the polyamide resin described above) and the fiber reinforced resin layers are each made of the epoxy resin , This resin combination provides excellent intercoat adhesion between these layers. When the resin for the fiber-reinforced resin layers is the epoxy resin as described above, it is easier to impregnate the fabric with the resin and to give the fiber-reinforced resin layers suitable strength. When the material for the vibration-damping layers is the polyamide resin, the vibration-damping properties are improved.

The vibration-damping layers of the thermosetting resin are formed by repeatedly applying a solution of the thermosetting resin. The vibration-damping layers of the thermoplastic resin are formed by extruding the thermoplastic resin through a T-die to form sheets of thermoplastic resin (thermoplastic resin films) each having a desired thickness and layering or stacking the sheets. Alternatively, the anti-vibration layers may be twill weave, plain weave, or satin weave continuous filament twill weave of any of the foregoing synthetic resins (preferably a continuous filament of a polyamide 6 or a polyamide 66). The vibration damping layers are preferably each made of the thermoplastic resin layers in view of the vibration damping properties or, preferably, the fabrics each made of any of the above-mentioned synthetic resins in terms of interlayer adhesion, flexural strength and flexural elongation are (preferably the fabrics of the polyamide 6 or the polyamide 66). In particular, the resin contained in the fiber reinforced resin layers penetrates the weave textures of the Tissue of the vibration damping layers, whereby a firm inter-layer adhesion is ensured. Furthermore, the weave textures of the fabrics enhance the flexural properties of the vibration damping layers. The fabrics for the vibration damping layers are preferably 1 cm wide fabrics, each woven from 39 to 65 continuous filaments each having a filament diameter of 0.01 to 0.08 mm. The fabrics each have a thickness of 0.02 to 0.1 mm and a weight of 1.4 to 1.7 g / cm ² in terms of flexural strength, flexural elongation and the like.

The fiber-reinforced resin layers and the vibration-damping layers are laminated in a sequence defined in the present disclosure, and if necessary, the resulting laminate is formed into a predetermined shape using a mold. In this way, the intended vibration damping molded product is made of fiber reinforced resin.

When the resin for the fiber-reinforced resin layers is the thermosetting resin and the vibration-damping layers are each made of the thermoplastic resin, the fiber-reinforced resin layers are respectively formed by the above-mentioned hand lamination molding method, and the vibration-damping layers are respectively stacked or stacked Films formed from thermoplastic resin. In this way the intended laminate is produced. When the laminate is to be formed into the desired shape, the laminate is placed in a bag evacuated by a vacuum pump and then pressed by a press machine (at a pressure of 5 kN to 100 kN). The laminate can be kept at a suitable temperature during pressing.

When the resin for the fiber-reinforced resin layers is the thermoplastic resin and the vibration-damping layers are each made of the thermosetting resin, the fiber-reinforced resin layers are respectively stacked or stacked with the fabric and the thermoplastic resin layer and hot-pressed the resulting stack for melting the thermoplastic resin layer, and the vibration damping layers are respectively formed by repeatedly applying the resin solution. In this way the intended laminate is produced. The hot pressing operation may be performed at a temperature not lower than the melting point of the thermoplastic resin or at a temperature not lower than the hardening point of the vibration damping layers after all the above steps including applying the resin solution to the vibration damping layers Layers, have been performed. Optionally, the laminate may be formed into the desired shape using a die in the hot pressing process.

The vibration damping molded product of fiber reinforced resin prepared in the above-described manner according to the present disclosure has excellent strength, rigidity and excellent vibration damping properties, and is better in bending flexure, fatigue resistance and heat resistance than a conventional FRP. Therefore, the vibration damping molded product of fiber reinforced resin is advantageously used as a component of a motor vehicle component, such. As a torsion bar or a torsion spring, a handlebar, a lower arm, a strut, a propeller shaft, an impact carrier, a stabilizer, a subframe or subframe or axle carrier, a bumper or a side door support used. The vibration damping molded product of fiber reinforced resin according to the present disclosure, which has a characteristic laminate structure, can be used in various fields of application (e.g., as a component of a robot fork, a bridge, a building, a wheelchair, an electric vehicle, etc.) Bicycle or the like).

EXAMPLES

Next, examples of the invention together with comparative examples and reference examples will be described. It should be noted, however, that the present disclosure within the scope of the disclosure is not limited to these inventive examples.

[Examples 1 to 12 and Comparative Examples 1 to 5]

Fiber-reinforced resin laminates were prepared by the hand lay-up molding method by stacking or stacking layers on a flat surface so as to have the laminate structures shown in Tables 1, 2 and 4, respectively. "CFRP" layers shown in Tables 1, 2 and 4 were respectively obtained by mixing an epoxy resin (DAITOCIZER 828, available from Daito Sangyo Co., Ltd.) and a curing agent (ADEKA HARDENER EH6007, available from ADEKA Corporation) in a weight ratio of (epoxy resin) :( curing agent) = 2: 1 for preparing a resin solution, preparing a carbon fiber fabric (TENAX, Toho Tenax Co., Ltd.) having a 2 mm wide weave structure woven in a twill weave of 3,000 carbon filaments (each having a filament diameter of 7 μm) and a weight of 200 g / m ² and a thickness of 0.25 mm, and impregnating the carbon fiber fabric with the resin solution by uniformly applying the resin solution to the carbon fiber fabric by a roller. "PA12" layers shown in Tables 1, 2 and 4 were respectively formed by stacking or stacking films of a polyamide 12 alloy material (3030J16L, available from Ube Industries, Ltd.), and "PA6" Layers shown in Tables 1, 2 and 4 were respectively formed by stacking or stacking films of a polyamide 6 alloy material (ST811HS, available from EI du Pont de Nemours & Company). "PA6 fabric" layers shown in Tables 1, 2 and 4 were fabrics woven with a plain weave weaving machine from AMIRAN 235T-24-720 filaments (available from Toray Industries, Inc.) and "PA66 fabric" layers shown in Tables 1, 2, and 4 were plain weave fabrics (4700, available from Asahi Kasei Textile, Ltd.). In Tables 1, 2 and 4, "X / Y" values were respectively calculated as set out in claim 1, and "d / D" values were calculated as set forth in claim 1, respectively.

[Examples 13 to 16]

Fiber-reinforced resin laminates were prepared by the hand lay-up molding method by stacking or stacking layers on a flat surface so as to have laminate structures as shown in Table 3, respectively. "CFRP" layers shown in Table 3 were each prepared by mixing 100 parts by weight of an epoxy resin (DAITOCIZER 828, available from Daito Sangyo Co., Ltd.), 50 parts by weight of a curing agent (ADEKA HARDENER EH6007, from ADEKA Corporation available) and 5 parts by weight of an inorganic material (TISMO D, available from Otsuka Chemical Co., Ltd.) by means of three rolls (available from Inoue MFG, Inc.) for preparing a resin solution, preparing a carbon fiber fabric (TENAX, Toho Tenax Co. Ltd.) having a 2 mm wide weave structure woven in a twill weave of 3000 carbon filaments (each having a filament diameter of 7 μm) and a weight of 200 g / m ² and a thickness of 0.25 mm and Impregnating the carbon fiber fabric with the resin solution by uniformly applying the resin solution to the carbon fiber fabric formed by a roller. "PA6 fabric" layers shown in Table 3 were fabrics woven with a plain weave weaving machine from AMIRAN 235T-24-720 filaments (available from Toray Industries, Inc.), and " PA66 fabric layers shown in Table 3 were plain weave fabrics (4700, available from Asahi Kasei Textile, Ltd.). In Table 3, "X / Y" values were respectively calculated as set out in claim 1, and "d / D" values were calculated as set forth in claim 1, respectively.

[Reference Example 1]

In Reference Example 1, a 2.0 mm thick steel plate was produced.

[Reference Example 2]

In Reference Example 2, a 2.0 mm thick aluminum plate was produced.

The fiber-reinforced resin laminates thus prepared in Examples and Comparative Examples and the metal plates prepared in Reference Examples were evaluated for characteristic properties based on the following criteria, respectively. The results of the evaluation are also shown in Tables 1 to 4 below.

[Flexural modulus]

The laminates (and the metal plates in the Reference Examples) were each cut into a strip having a size of 150 mm x 10 mm. The strip was used as a sample to measure the flexural modulus of elasticity. The bending elastic modulus (MPa) of the sample was measured according to JIS K7074 by performing a three-point bending test at room temperature with a test speed of 2 mm / min and a distance between the clamp points of 64 mm using a stress gradient with a strain amount of 0.05 to 0. 25% measured.

[Flexural strength]

The laminates (and the metal plates in the Reference Examples) were each cut into a strip having a size of 150 mm x 10 mm. The strip was used as a sample for measuring flexural strength. The flexural strength (MPa) of the sample was measured according to JIS K7074 by performing a three-point bending test at room temperature with a test speed of 2 mm / min and a distance between the chucking points of 64 mm.

[Bending elongation]

The laminates (and the metal plates in the Reference Examples) were each cut into a strip having a size of 150 mm × 10 mm. The strip was used as a sample for measuring flexural elongation. The flexural strain (%) of the sample was determined according to JIS K7074 based on a displacement measured when the sample was subjected to a three-point bending test at room temperature with a test speed of 2 mm / min and a distance between the clamp points of 64 mm was performed, was broken.

[Damping coefficient]

The laminates (and the metal plates in the Reference Examples) were each cut into a strip having a size of 150 mm x 10 mm. The strip was used as a sample to measure the attenuation coefficient. The steady-state loss factor (the damping coefficient) of the sample was determined in accordance with JIS G0602 "Test Method for Vibration-Absorbing Properties in Compressed-Type Laminated Seating Steel Sheets" by performing a jib impact test and then applying Hilbert transformation.

The above results show that the fiber reinforced resin laminates of Examples have excellent rigidity with higher flexural strength and excellent vibration damping properties with a higher attenuation coefficient.

In contrast, the fiber-reinforced resin laminate of Comparative Example 1 in which no vibration-damping layer was provided was inferior in vibration-damping properties with a lower damping coefficient than the fiber-reinforced resin laminates of Examples. The fiber-reinforced resin laminate of Comparative Example 2 in which only one vibration-damping layer was provided was inferior in vibration damping properties with a lower damping coefficient than the fiber-reinforced resin laminates of Examples. The fiber reinforced resin laminate of Comparative Example 3 in which many PA layers were provided as vibration damping layers, and thus the ratio (d / D) of the total thickness of the PA layers to the thickness of the laminate was greater than the range dictated by the present invention Disclosure, exhibited inferior stiffness with lower flexural strength than the fiber reinforced resin laminates of the examples. The fiber reinforced resin laminates of Comparative Examples 4 and 5 in which the ratio (d / D) of the total thickness of the PA layers to the thickness of the laminate was within the range defined by the present disclosure, but where the interface between the CFRP layer and the PA layer was too far away from the central laminate plane (X / Y was larger than the range specified by the present disclosure) with the PA layers arranged as vibration damping layers in extreme positions, exhibited inferior stiffness with lower flexural strength than the fiber reinforced resin laminates of the examples.

While specific embodiments of the present disclosure have been shown in the above-mentioned inventive examples, the examples of the present invention are merely illustrative of the disclosure, but do not limit the disclosure. It is intended that various modifications may be made within the scope of the disclosure which would be familiar to those skilled in the art.

The vibration damping molded product of fiber reinforced resin according to the present disclosure, which has a characteristic laminate structure, can be used not only as a component of an automotive component but also in various application fields (eg, as a component of a robot fork, a bridge, a building, a wheelchair, an electric vehicle, a bicycle or the like).

LIST OF REFERENCE NUMBERS

1

LAYER OF FIBER REINFORCED RESIN

2

VIBRATION DAMPING LAYER

Claims (10)

A vibration-damping molded product of fiber-reinforced resin of a laminate, comprising: Fiber reinforced resin layers, each comprising a resin impregnated fabric, and vibration damping layers of a synthetic resin, wherein the vibration damping layers comprise upper and lower vibration damping layers, wherein the fiber-reinforced resin layers comprise a fiber-reinforced resin central layer located between the upper and lower vibration-damping layers at a center position with respect to a thickness direction of the laminate, and fiber-reinforced resin outer layers respectively facing away from the upper and lower ones vibration damping layers are provided, wherein the laminate has a central laminate plane with respect to its thickness direction, wherein a distance (X) from the central laminate plane to an interface between the fiber reinforced resin central layer and each of the upper and lower vibration damping layers and a distance (Y) from the central laminate plane to each of opposite surfaces of the laminate is X / Y = 0.19 to 0.89 and satisfy wherein the total thickness (d) of all the vibration damping layers of the laminate and the thickness (D) of the laminate satisfy the relationship d / D = 0.02 to 0.18. A vibration damping molded product of fiber reinforced resin according to claim 1, wherein the synthetic resin for the vibration damping layers is a polyamide resin, wherein the resin for the fiber reinforced resin layers is an epoxy resin. A vibration damping molded product of fiber reinforced resin according to claim 1 or 2, wherein the vibration damping layers each comprise a synthetic resin woven fabric. A vibration-damping molded product of fiber-reinforced resin according to any one of claims 1 to 3, wherein the fiber-reinforced resin central layer comprises a laminate comprising a plurality of fiber-reinforced resin layers. A vibration damping molded product of fiber reinforced resin according to any one of claims 1 to 4, wherein the thickness (D) of the laminate is 1.9 to 7.4 mm. A vibration-damping molded product of fiber-reinforced resin according to any one of claims 1 to 5, wherein the vibration-damping layers each have a thickness of 0.04 to 0.4 mm. The vibration-damping molded product of fiber-reinforced resin according to any one of claims 1 to 6, wherein the fabric is a twill weave, plain weave or satin weave fabric of a continuous filament selected from a carbon filament, a glass filament, an aramid filament and a basalt filament. A vibration-damping molded product of fiber-reinforced resin according to any one of claims 1 to 7, wherein the resin for the fiber-reinforced resin layers contains at least one inorganic material selected from the group consisting of potassium titanium oxide, aluminum oxide, zinc oxide and titanium oxide. A vibration damping molded product of fiber reinforced resin according to any one of claims 1 to 8, wherein the vibration damping molded product of fiber reinforced resin is in a sheet form and provided with a predetermined shape. A motor vehicle component comprising the fiber-reinforced resin vibration damping molded product according to any one of claims 1 to 9 as the component thereof, the automotive component being one of a torsion bar or a torsion spring, a handlebar, a lower arm, a strut, a propeller shaft, an impact beam, a stabilizer , a subframe or subframe or axle carrier, a bumper and a side door carrier.

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