JP2016075755A - Wire harness with acoustic absorbing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wire harness with an acoustic absorbing material such that the acoustic absorbing material is fixed to the wire harness without deteriorating acoustic absorbing performance.SOLUTION: There is provided a wire harness with an acoustic absorbing material such that while at least a part of the wire harness in an axial direction is covered with one or a plurality of acoustic absorbing materials, the wire harness and acoustic absorbing material are united. The acoustic absorbing materials are made of non-woven fabric, superposed at least partially one over another in a thickness direction, and fixed to the wire harness by connecting superposed parts by a fixing member, which has a shaft part penetrating the superposed parts in the thickness direction, an axial length of the shaft part being 5 mm or larger.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a wire harness with a sound absorbing material in which a sound absorbing material using a nonwoven fabric and a wire harness are integrated.

  Conventionally, for the purpose of enhancing the quietness of a vehicle interior of a car, a sound insulating material made of glass wool, rock wool, porous ceramic, urethane foam, waste cotton, etc. A sound absorbing material was provided. However, from the viewpoints of workability, impact on human body, recyclability, environmental load, and weight reduction of sound insulation materials and sound absorption materials, nonwoven fabrics are now widely used for these sound insulation materials and sound absorption materials. .

  In recent years, high performance and high functionality have been rapidly promoted mainly in automobiles and electrical appliances. In order to accurately operate various electronic equipment such as automobiles and electrical appliances, it is necessary to use a plurality of electric wires for the internal wiring. These plurality of electric wires are generally used in the form of a wire harness. A wire harness is a structure in which a plurality of electric wires are pre-assembled into a form necessary for wiring. After performing necessary branching, attaching a connector to a terminal, etc., various types such as a tape shape, a tube shape or a sheet shape It is formed by winding a wire harness protective material having a shape around the outer periphery of an electric wire bundle.

  A wire harness mounted on an automobile is routed in the vehicle to electrically connect various electrical components including the above-mentioned noise generating device. May cause noise. Therefore, the outer periphery of the wire harness may be provided with a cushioning material for suppressing noise due to contact with other members or the like.

JP 2008-296599 A

  With the recent spread of EV (Electric Vehicle) technology in the automobile market, there is a growing need for quietness in the vehicle compartment. In order to improve the quietness of the interior of the vehicle, noise from the low frequency range to the high frequency range, such as road noise and wind noise, which was a problem with gasoline cars, and noise in the high frequency range above 5000 Hz generated from the motor It is necessary to take measures. As part of such measures, there are various vehicle designs such as vehicle design that considers noise reduction, sound absorbing material that absorbs noise in a wide sound range from low frequency to high frequency, resin members that have sound insulation performance equivalent to metal parts, etc. A method has been devised.

  When arranging a sound absorbing material that absorbs noise in the wiring area of the wire harness, the wire harness and the sound absorbing material are usually assembled in the vehicle as separate parts. The sound absorbing material made of non-woven fabric also has a function as a cushioning material for the wire harness, and as a method of integrating and assembling such a sound absorbing material and the wire harness, a structure in which the wire harness is sandwiched between two sound absorbing materials, A configuration in which a single sound absorbing material is wound around a wire harness and fixed can be considered. However, when these are fixed by bonding with an adhesive tape, the resin layer by the adhesive tape inhibits noise absorption, so the original sound absorption characteristics of the nonwoven fabric cannot be obtained, and even when bonded by ultrasonic welding, Since the thickness of the fixing portion of the sound absorbing material is reduced, there is a problem that the sound absorbing characteristics inherent to the nonwoven fabric cannot be obtained.

  In view of the above problems, the problem to be solved by the present invention is to provide a wire harness with a sound absorbing material in which the sound absorbing material is fixed to the wire harness without deteriorating its sound absorbing performance.

  In order to solve the above problems, a wire harness with a sound absorbing material according to the present invention is the wire harness and the sound absorbing material in a state where at least a part of the wire harness in the axial direction is covered with one or more sound absorbing materials. Is a wire harness with a sound absorbing material, wherein the sound absorbing material is made of non-woven fabric, the sound absorbing material is at least partially overlapped in the thickness direction, and the overlapped portions are connected by a fixing member. The fixing member has a shaft portion that penetrates the overlapped portion in the thickness direction, and the axial length of the shaft portion is 5 mm or more.

  In the above-described wire harness with a sound absorbing material, it is preferable that locking portions extending in a radial direction of the shaft portion are provided at both ends of the shaft portion.

  In the above-described wire harness with a sound absorbing material, the fixing member is preferably a resin tag pin.

  In the wire harness with a sound absorbing material, the sound absorbing material is formed by laminating a skin material nonwoven fabric and a base material nonwoven fabric having a larger basis weight than the skin material nonwoven fabric, and at least a part of the wire harness includes the two sound absorbing materials. It is preferable that the two sound absorbing materials are covered with the sound absorbing material by being sandwiched between them, and the two sound absorbing materials have the same thickness direction.

  According to the wire harness with a sound absorbing material according to the present invention, the sound absorbing material can be fixed to the wire harness without deteriorating its sound absorbing performance.

It is an external appearance perspective view which shows the wire harness with a sound-absorbing material concerning this embodiment. It is a schematic diagram which shows the fixing structure of the sound-absorbing material by the tag pin. It is a schematic diagram which shows the alternative means of a tag pin. It is an external appearance perspective view which shows the wire harness with a sound absorption material by which the sound absorption material of 1 sheet was wound. It is explanatory drawing of the test apparatus of a test of normal incidence sound absorption coefficient. It is a graph which shows the influence on the sound absorption performance by the fixing method. It is explanatory drawing which shows the structure of the test piece of a shear adhesion test.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an external perspective view showing a wire harness 1 with a sound absorbing material in the present embodiment. The wire harness with a sound absorbing material of the present invention can be suitably used as a sound absorbing material for a vehicle such as an automobile, and is disposed in the interior of a dashboard of a car or in an interior space of a door. The noise that intrudes into the passenger compartment from the space that generates noise is blocked.

  The wire harness 1 with sound absorbing material is integrated in a state where a part of the wire harness 9 in the axial direction is sandwiched between sound absorbing materials 21 and 22 which are two sound absorbing materials. These sound absorbing materials 21 and 22 are overlapped in the thickness direction, and the end portions of the overlapped portions are fixed to the wire harness 9 by being connected by tag pins 3 that are fixing members.

  Examples of the wire harness 9 include a bundle of a plurality of electric wires whose core wire is covered with an insulator and a wire harness 9 that is configured by only one electric wire.

  The tag pin 3 is a resin binder that is widely distributed in general. As shown in FIG. 2, the tag pin 3 has a shaft portion 31 that penetrates the ends of the sound absorbing materials 21 and 22 in the thickness direction. Locking portions 32 extending on both sides in the radial direction are provided at both ends of the shaft portion 31, and the sound absorbing materials 21 and 22 are clamped by the two locking portions 32, thereby restricting movement in the thickness direction. ing.

  As the tag pin 3 in the present embodiment, one having a shaft portion length of 5 mm or more is used. Since the shaft portion 31 of the tag pin 3 has such a length that the thickness of the sound absorbing materials 21 and 22 is not greatly reduced, that is, the sound absorbing performance of the sound absorbing materials 21 and 22 is not impaired. Both the maintenance of sound absorption performance and strong connection are achieved.

  In addition, the sound absorbing materials 21 and 22 exhibit better sound absorbing performance when a slight gap (air layer) is provided than when these facing surfaces are in close contact with each other. When a tag pin having a shaft part that is slightly longer than the thickness of the sound absorbing materials 21 and 22 is used, the sound absorbing materials 21 and 22 can be separated by the surplus, for example, the wire harness 9 is inserted through them. When the sound absorbing material is pressed in the separation direction, an air layer is easily formed between the sound absorbing materials.

  In the present embodiment, the tag pins 3 are attached to a total of six locations in the longitudinal center at the four corners of the sound absorbing materials 21 and 22 and the ends in the direction orthogonal to the axial direction of the wire harness 9. The attachment location and attachment interval of the tag pins 3 are not limited to the aspect of the present embodiment, and can be appropriately adjusted according to the size of the sound absorbing material and the required fixing force.

  Although the tag pin is adopted as the fixing member in the present embodiment, it can be obtained at low cost because the tag pin is widely distributed, and it can be efficiently attached to the sound absorbing material using the tag gun. This is because the fixing member is not necessarily limited to the tag pin. Other fixing members include, for example, a metal wire-like member penetrating in the thickness direction of the sound-absorbing material and bent at its end (FIG. 3A), or a thin shaft bolt-like member The end part of which is made by inserting a nut-like member into the end part (FIG. 3 (b)) or a resinous thread-like binding tool called a loop lock or a thread loop. A concatenated one (FIG. 3C) is conceivable. In short, any member having an elongated shaft portion and capable of connecting the sound absorbing materials without greatly reducing the thickness of the sound absorbing material can be employed as the fixing member.

  The sound absorbing material 21 is a nonwoven fabric laminated body in which a skin material nonwoven fabric 211 and a base material nonwoven fabric 212 having a larger basis weight than the skin material nonwoven fabric 211 are laminated. Similarly, the sound absorbing material 22 is also a skin material nonwoven fabric 221 and the skin material. This is a nonwoven fabric laminate in which a base nonwoven fabric 222 having a larger basis weight than the nonwoven fabric 221 is laminated. The skin material nonwoven fabric and the base material nonwoven fabric have different characteristics regarding absorption and reflection of sound due to different basis weights, and by laminating them, it is possible to absorb sound in a wide frequency band. Although the skin material nonwoven fabrics 211 and 221 in this embodiment are laminated | stacked only on the single side | surface of the base nonwoven fabrics 212 and 222, these may be laminated | stacked on both surfaces.

  The sound absorbing materials 21 and 22 serve not only as a sound absorbing material but also as a cushioning material for the wire harness 9 by covering a part of the wire harness 9 and covering it.

  The sound absorbing materials 21 and 22 in the present embodiment have the same thickness direction, and the skin material nonwoven fabrics 211 and 221 are oriented in the same direction. The skin material nonwoven fabrics 211 and 221 are preferably directed to the noise source side for sound absorption effect.

  The skin material nonwoven fabric and the base material nonwoven fabric constituting the sound absorbing materials 21 and 22 may be simply overlapped, but it is more desirable to integrate them by heat welding, needle punching, or the like. Moreover, you may make it closely_contact | adhere between each nonwoven fabric, and some space may be provided.

The skin material nonwoven fabrics 211 and 221 preferably have a weight per unit area of 10 to 400 g / m ² and a thickness of 0.1 to 4.0 mm. When the weight per unit area or thickness is larger than the range, the difference in sound absorption characteristics from a general sound absorbing material is lost, and the effect of providing a skin material may not be obtained. On the other hand, if the weight per unit area or thickness is smaller than the range, the sound absorbing effect as the sound absorbing material may not be sufficiently exhibited.

The base nonwoven fabrics 212 and 222 preferably have a basis weight of 100 to 1000 g / m ² and a thickness of 1.0 to 50.0 mm. When the basis weight increases, the sound absorption coefficient in all frequency bands increases, and when the basis weight decreases, the sound absorption coefficient in all frequency bands tends to decrease. Further, when the thickness is increased, the sound absorption performance in the low frequency band is increased, and when the thickness is decreased, the sound absorption characteristic in the high frequency band tends to be increased. The thicknesses of the base nonwoven fabrics 212 and 222 can be appropriately adjusted according to the frequency band to be absorbed.

  The fiber diameters of the skin material nonwoven fabrics 211 and 221 are preferably in the range of 1 to 50 μm, and the fiber diameters of the base nonwoven fabrics 212 and 222 are preferably in the range of 4 to 100 μm. The thinner the fiber diameter, the higher the sound absorbing performance as a nonwoven fabric. However, if the fiber diameter is too thin, the nonwoven fabric may become brittle.

  Examples of the fiber material that can be used for each nonwoven fabric include polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyolefin, nylon, polyamide, polyvinyl chloride, rayon, acrylic, acrylonitrile, cellulose, kenaf, and glass.

  As a manufacturing method of each nonwoven fabric, a needle punch method, a spunbond method, a spunlace method, a melt blown method, or the like can be used.

  In this embodiment, the two sound absorbing materials 21 and 22 are used, but the sound absorbing material 21 is wound around the wire harness 9 like the wire harness 11 with the sound absorbing material shown in FIG. It is good also as a structure which connects the edge part with the tag pin 3. FIG. Moreover, although the sound-absorbing materials 21 and 22 are nonwoven fabric laminated bodies which consist of a skin material nonwoven fabric and a base material nonwoven fabric, you may use the sound-absorbing material which consists only of any one nonwoven fabric.

  Below, the Example and comparative example of a wire harness with a sound-absorbing material which concern on this invention are shown. As the sound-absorbing material of this example and the comparative example, a nonwoven fabric obtained by integrating a skin material nonwoven fabric and a substrate nonwoven fabric having the following specifications by a needle punch method was used.

[Skin material non-woven fabric]
Fiber material: Olefin fiber Fiber diameter: φ9μm
Manufacturing method: Melt blown method basis weight: 50 g / m ²
Thickness: 1mm

[Base material nonwoven fabric]
Fiber material: Mixed fiber of polyester fiber and low melting point polyester fiber Fiber diameter: φ14μm
Manufacturing method: Needle punch method basis weight: 300 g / m ²
Thickness: 10mm

[Influence on sound absorption performance by fixing method]
The sound absorbing performance when the two sound absorbing materials were fixed by the following method was measured.
Example 1: Tag pin (manufactured by Toscabanak Co., Ltd .; Bannock pin 503SL18 mm)
Comparative Example 1: Double-sided tape (Nitto Denko Corporation; EW-514)
Comparative Example 2: Ultrasonic welding (Nippon Emerson Corporation; 2000X series ultrasonic welding machine)
Comparative Example 3: No fixing

  The sound absorption performance was compared by measuring the sound absorption rate of 500 to 5000 Hz by the normal incidence sound absorption rate test method of JISA1405-2. Two of the above sound-absorbing materials were processed into a circular shape of φ40 mm, and the vicinity of the center was fixed by the fixing method as a test specimen.

  FIG. 5 is a diagram showing a test apparatus used for measuring the normal incidence sound absorption coefficient. The test apparatus is composed of a straight cylindrical acoustic tube 5, and one end portion of the acoustic tube 5 and the vicinity thereof have a diameter-expanded portion 52 whose inner diameter is slightly larger than φ40 mm. The enlarged diameter portion 52 is provided with a back plate 53 that supports the test body 6, and the test body 6 is a portion other than the enlarged diameter portion 52 of the acoustic tube 5 with the base nonwoven fabric supported by the back plate 53. It arrange | positions in the position which plugs up the end of the main-body part 51. FIG. A speaker 54 as a sound source is disposed at the other end of the main body 51 and faces the skin material nonwoven fabric of the test body 6. Two attachment holes for the microphone 55 are provided along the axial direction on the tube wall on the slightly enlarged diameter portion 52 side from the center in the axial direction of the acoustic tube 5, and each of the attachment holes has a microphone. 55 is inserted.

In the above test apparatus, the incident sound (li) and reflected sound (lr) of the test sound emitted from the speaker 54 are collected by the microphone 55, and the normal incident sound absorption coefficient (α) is expressed by the following equation (1). Calculated by As shown in the equation (1), the normal incident sound absorption coefficient (α) is a ratio between an incident sound (li) of a plane wave of normal incidence and a sound (li-lr) which does not enter and return from the surface of the test body 6 among them. It is represented by
α (α = (li−lr) / li) (1)
The results are shown in Table 1 and FIG.

  As shown in Table 1 and FIG. 6, in the fixing method using the double-sided tape (Comparative Example 1), the sound absorption coefficient in the high frequency range is low due to the influence of the resin layer provided between the two sound absorbing materials. In the fixing method by ultrasonic welding (Comparative Example 2), the sound absorption coefficient is low in the entire frequency range due to the influence of the reduced thickness of the sound absorbing material. On the other hand, the sound absorbing material when the two sound absorbing materials are not fixed (Comparative Example 3) shows a relatively high sound absorbing performance in the entire frequency range, and the fixing method by the tag pin (Example 1) is not fixed ( The sound absorption performance equivalent to that of Comparative Example 3) is shown.

[Influence on fixing strength by fixing method]
The fixing strength when the two sound absorbing materials were fixed by the following method was measured.
Example 1: Tag pin (manufactured by Toscabanak Co., Ltd .; Bannock pin 503SL18 mm)
Comparative Example 1: Double-sided tape (Nitto Denko Corporation; EW-514)
Comparative Example 2: Ultrasonic welding (Nippon Emerson Corporation; 2000X series ultrasonic welding machine)
Comparative Example 3: No fixing

  The comparison of the fixing strength was performed by measuring the maximum strength in accordance with the shear adhesion test of JISK6850. The measurement was performed using a tensile tester at a speed of 100 mm / min. As the test piece 7, as shown in FIG. 7, the two sound absorbing materials processed into a rectangle of 100 mm × 25 mm were arranged so that the end portions in the longitudinal direction overlap each other in the thickness direction by 12.5 mm, and overlapped. What fixed the part with the said fixing method was used. In addition, the test piece 7 of Example 1 was fixed only with one tag pin. The results are shown in Table 2.

  The tensile strength of the fixing method using the double-sided tape (Comparative Example 1) or ultrasonic welding (Comparative Example 2) was 1.3 N and 8.4 N, respectively. The tensile strength of the fixing method using the tag pins (Example 1) was 15 5N, and it was confirmed that sufficient fixing strength could be obtained even by the fixing method using tag pins (Example 1).

  Based on the results of the normal incidence sound absorption coefficient test and shear adhesion test, fixing the sound absorbing material with a tag pin allows the sound absorbing material to be fixed with a fixing strength higher than the conventional fixing method without deteriorating the sound absorbing performance of the sound absorbing material. It was confirmed that.

  The embodiments, examples, and comparative examples of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments and the like, and various modifications can be made without departing from the spirit of the present invention. Modification is possible.

DESCRIPTION OF SYMBOLS 1 Wire harness 11 with a sound-absorbing material 11 Wire harness with a sound-absorbing material around which a sound-absorbing material 21 is wound 9 Wire harness 21, 22 Sound-absorbing material 3 Tag pin 32 Locking portion 211 Skin nonwoven fabric 212 of the sound-absorbing material 21 221 Non-woven fabric of skin material 222 of sound absorbing material 22 Non-woven fabric of base material 5 of sound absorbing material Acoustic tube 51 for normal incidence sound absorption coefficient test Main body portion 52 of acoustic tube 5 Expanded portion 53 of acoustic tube 5 Back plate 54 Speaker 55 Microphone 6 Vertical incidence Specimen 7 for sound absorption test Specimen for shear adhesion test

Claims (4)

In a state where at least a part of the wire harness in the axial direction is covered with one or more sound absorbing materials, the wire harness and the sound absorbing material are integrated with the wire harness,
The sound absorbing material is made of non-woven fabric,
The sound absorbing material is at least partially overlapped in the thickness direction, and the overlapped portion is fixed to the wire harness by being connected by a fixing member,
The fixing member has a shaft portion that penetrates the overlapped portion in the thickness direction,
The shaft portion has a length of 5 mm or more, and a wire harness with a sound absorbing material.   The wire harness with a sound absorbing material according to claim 1, wherein a locking portion extending in a radial direction of the shaft portion is provided at both ends of the shaft portion.   The wire harness with a sound absorbing material according to claim 2, wherein the fixing member is a resin tag pin. The sound absorbing material is formed by laminating a skin material nonwoven fabric and a base material nonwoven fabric having a larger basis weight than the skin material nonwoven fabric,
At least a part of the wire harness is covered with the sound absorbing material by being sandwiched between the two sound absorbing materials,
The wire harness with a sound absorbing material according to any one of claims 1 to 3, wherein the two sound absorbing materials have the same thickness direction.

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