JP2006142705A - Fibrous mat fixing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fibrous mat fixing structure which, being one for integrating a fibrous mat, such as a nonwoven mat, with a resin molding by ultrasonic processing, does not give rise to surface defects like unevenness and the like on the surface of the resin molding and by which shortening of the processing time and simplification of the processing equipment are attained. <P>SOLUTION: A luggage side trim (a sound-absorbent component for vehicle) 10 is obtained by integrally welding a fibrous mat such as a nonwoven fabric mat 30 to the rear face of a luggage side trim main body (a resin molding) 20, with an ultrasonic horn 50. The ultrasonic horn 50 has a sharp protrusion 52 formed on a flat pressing face 51 and therefore the welded part 40 of the nonwoven fabric mat 30 has, in addition to a flat welded face 41, a V groove 42 formed therein that eats into the inside of the resin molding 20 and therefore the fiber in the nonwoven fabric mat 30 easily eats into the melting face of the resin molding 20 thus to give a reason to expect an anchor effect. Since the formation of the V groove 42 for the resin molding 20 can be performed in a short time, the workability improves and appearance defects can be eliminated. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fixing structure of a fibrous mat, and in particular, when a fibrous mat is integrated with a resin molded product made of a thermoplastic resin by ultrasonic welding, a strong bonding strength can be obtained with a short welding process. The present invention relates to a fixing structure of a fibrous mat obtained.

  Usually, an interior trim made of a resin molded product is attached to the vehicle body panel on the interior surface side of the vehicle body panel via an attachment means such as a clip. The interior trim of the interior trim is shown in FIG. As described above, the sound absorbing member 2 is bonded and fixed to the back surface of the interior trim 1 via the adhesive 3, and the sound absorbing member 2 prevents the noise outside the vehicle from being propagated into the vehicle interior, thereby improving the quietness in the vehicle interior. It is configured.

  As the interior trim 1, since it can be molded into a desired curved shape, an injection molded body of a thermoplastic resin such as polypropylene (PP) resin, polyethylene (PE) resin, ABS resin, or a mold press molded body is used. As the member 2, a fiber mat such as a felt or a nonwoven fabric mat is used.

  In recent years, attention has been paid to a structure in which the sound absorbing member 2 such as a fiber mat is fixed by ultrasonic welding because it prevents deterioration of the working environment due to the adhesive and can be easily recycled. This ultrasonic processing method is described in detail in Patent Document 1. The outline of Patent Document 1 will be described with reference to FIG. First, the sound absorbing member 2 such as a nonwoven fabric mat is set on the body panel surface of the interior trim 1 made of a synthetic resin molded product, and the ultrasonic horn 4 is pressed from the sound absorbing member 2 side with a predetermined pressure to ultrasonic vibration with a predetermined frequency. Is added, the welded portion of the interior trim 1 and the sound absorbing member 2 is melted and integrated, and as shown in the figure, the ultrasonic horn 4 is added so as to secure a large boundary area between the two. The pressure surface is processed into an uneven shape having an uneven surface 4a.

Japanese Patent Laid-Open No. 11-5267

  However, in the structure in which the sound absorbing member 2 is ultrasonically welded to the interior trim 1 using the ultrasonic horn 4 provided with the uneven surface 4a as the pressure surface, a depth of 1 to 5 mm is formed on the boundary surface of the interior trim 1. Since the ultrasonic horn 4 must be subjected to ultrasonic processing by applying a large pressing force so that a large number of recesses are formed, the cylinder in the press machine that applies the pressing force to the ultrasonic horn 4 This is a major factor that reduces productivity, such as an increase in capacity, a longer processing time, a greater equipment cost, and a longer work time. Further, it has been pointed out at the same time that the appearance of defects such as sink marks and irregularities on the product surface of the interior trim 1 is likely to occur due to the formation of deep irregularities in the welded part, leading to a decrease in appearance design.

  The present invention has been made in view of such circumstances, and a structure suitable for a sound absorbing part for a vehicle or the like, that is, a fibrous mat such as a non-woven mat having excellent sound absorbing property is provided on the panel-facing surface of a thermoplastic resin plate. The fiber mat fixing structure is integrated by ultrasonic welding, which requires low pressure and requires less processing time. This simplifies equipment, increases productivity, and enhances the appearance. It is another object of the present invention to provide a fiber mat fixing structure that can be maintained well.

  In order to achieve the above object, the present inventor has devised the shape of the pressure surface of the ultrasonic horn so that the fibers in the fiber mat melt the synthetic resin plate in addition to the melting action by ultrasonic processing. Focusing on the expectation of a so-called anchor effect that bites into the surface, the present invention has been completed.

  That is, the present invention attaches a fiber mat to the panel facing surface of a resin molded product attached to the interior surface side of the vehicle body panel, performs welding with an ultrasonic horn for each predetermined spot, and forms the fiber mat into a resin In the fixing structure of the fiber mat to be fixed to the product, the welded portion of the fiber mat protrudes from the flat welding surface pressed against the flat pressure surface of the ultrasonic horn and the pressure surface of the ultrasonic horn. Each of the fibers of the fibrous mat is composed of V-grooves that bite into the resin molded product by the sharp ridges.

  Here, as a material of the synthetic resin plate, any thermoplastic resin such as PP resin, PE resin, ABS resin, etc. can be used, and it is formed into a required shape by injection molding or mold press molding. In addition, as the fibrous mat, a material in which fibers are accumulated in a mat shape such as a non-woven mat or felt can be used. As the fiber, synthetic fiber such as PP fiber, PE fiber, polyester fiber, natural fiber, etc. is used as the base fiber, and the structure can be ultrasonically welded, that is, low melting point fiber is mixed in part as binder fiber. It ’s fine. More preferably, the binder fiber is preferably the same type of resin as the synthetic resin molded product because compatibility of the resins can be expected.

  Next, the structure of the welded portion between the resin molded product and the fiber mat includes a flat weld surface that melts and integrates the boundary surface by pressurizing an ultrasonic horn, and a V groove that further penetrates into the resin molded product from the flat weld surface It consists of. The V-groove can be set to an arbitrary pattern shape such as a cross shape, a radial shape, a frame shape, or a lattice shape, but the depth of the V-groove is 1 mm or less, preferably in the range of 0.3 to 0.8 mm. good.

  Accordingly, the ultrasonic horn to be used has a sharp ridge projectingly formed on the flat pressure surface in order to form a flat weld surface and a V-groove at the welded portion of the resin molded product and the fiber mat. The ridge forms a V-groove. Furthermore, the processing conditions of the ultrasonic horn are preferably applied pressure: 0.5 to 0.6 MPa, processing time: 0.1 to 0.5 sec, and frequency: 28 to 40 kHz.

  According to the fixing structure of the fibrous mat according to the present invention, when the fibrous mat is joined and integrated with the resin molded product by ultrasonic processing, the fibrous mat is resinized by the flat welded surface and the V-groove as a welding portion. Since it is configured to be welded and integrated with the molded product, the V-groove can be easily formed with sharp ridges formed on the pressure surface of the horn even with low pressure, enabling cylinder drive with a small capacity. In addition to the melting action by ultrasonic processing, the V-groove can be expected to have an anchor effect that the fibers of the fiber mat bite into the molten surface of the resin molded product, and is stronger due to the strength by ultrasonic welding and the joint strength by the anchor effect. High bonding strength can be obtained. In addition, since the amount of melting of the resin molded product is small, appearance defects such as sink marks and irregularities do not occur on the product surface of the resin molded product.

  As described above, according to the fixing structure of the fiber mat according to the present invention, when the fiber mat is welded and integrated on one surface of the resin molded product by ultrasonic processing, the ultrasonic horn is flat at the welded portion of both. Both are welded and integrated on the pressing surface, and a V-groove is formed on the flat welding surface by sharp ridges formed on the pressing surface of the horn, forcing the fibers of the fiber mat to the molten part of the resin molded product. By making it bite into the surface, an anchor effect can be expected, and a strong bonding strength can be obtained even in a short time welding process.

  Therefore, since the pressure applied to the ultrasonic horn may be low, a compact air cylinder can be used as a press to apply pressure to the ultrasonic horn, the equipment can be simplified, and the welding time can be reduced. The workability can be improved by shortening the length and the appearance appearance can be improved.

  Hereinafter, embodiments of a fiber mat fixing structure according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 to FIG. 5 show a first embodiment of the present invention. FIG. 1 is a perspective view of a luggage side trim with a nonwoven fabric mat affixed to the back side as seen from the back side, and FIG. 2 is affixed to the luggage side trim body. 3 is a front view showing the nonwoven fabric mat, FIG. 3 is a sectional view showing the structure of the welded portion of the nonwoven fabric mat, FIG. 4 shows the shape of the ultrasonic horn used in the first embodiment, and FIG. FIG. 5B is a cross-sectional view showing the fiber mat welding process using the ultrasonic horn shown in FIG. 4, and FIGS. 6 to 9 are the first embodiment. It is each explanatory drawing which shows the modification of an example.

  In FIG. 1, a luggage side trim 10 is mounted on an interior surface of a side wall panel in a luggage room of a vehicle. The luggage side trim 10 is a rear surface of a luggage side trim main body 20 made of a resin molded product of a thermoplastic resin. The non-woven mat 30 is generally composed of a non-woven mat 30 attached to the body panel facing surface. More specifically, the luggage side trim main body 20 is composed of an injection molded body of PP resin, and a vertical wall flange 21 is formed at one edge portion, and a mounting piece 22 for projecting to the vehicle body panel projects from the other flange. A screw hole 23 is formed in the mounting piece 22.

  And the nonwoven fabric mat 30 mainly provided with the sound absorption function is affixed to the back surface of the luggage side trim main body 20. The present invention is characterized by a fixing structure for fixing the nonwoven fabric mat 30 to the luggage side trim main body 20. . That is, the nonwoven fabric mat 30 has an outer shape that is slightly smaller than the outer shape of the luggage side trim main body 20, and as shown in FIG. 2, the luggage side trim is firmly formed by a plurality (6 in the embodiment) of the welded portions 40. It is fixed to the main body 20.

  FIG. 3 shows a cross-sectional structure of the welded portion 40 of the nonwoven fabric mat 30. The welded portion 40 of the nonwoven fabric mat 30 is substantially circular with respect to the back surface of the luggage side trim body 20 having a plate thickness of 2.0 to 3 mm. The flat welding surface 41 and a cross-shaped V groove 42 that bites into the luggage side trim main body 20 from the flat welding surface 41. The depth of the V groove 42 (indicated by reference sign d1 in FIG. 3) is set to 1 mm or less. In the present embodiment, the nonwoven fabric mat 30 uses a high-melting polyester fiber and PP fiber mixed nonwoven fabric, and the flat welded surface 41 of the welded portion 40 is subjected to ultrasonic processing of an ultrasonic horn 50 described later. The surface side of the resin surface of the luggage side trim main body 20 is partially melted, and a part of the PP fiber, which is a low-melting fiber in the nonwoven fabric mat 30, is melted. The luggage side trim main body 20 and the nonwoven fabric mat 30 are welded and integrated.

  Furthermore, in the V-groove 42, at the interface between the luggage side trim main body 20 and the nonwoven fabric mat 30, both of them are welded by melting of the resin on the side of the luggage side trim main body 20 and melting of the binder fibers in the nonwoven fabric mat 30. In particular, the base fiber (high melting point polyester fiber) in the nonwoven fabric mat 30 bites into the molten surface of the luggage side trim main body 20 and can be expected to have an anchor effect, and the nonwoven fabric mat 30 and the luggage side trim main body at the boundary of the V groove 42. Thus, a strong bonding strength can be obtained.

  Next, FIG. 4 is an explanatory view showing the structure of the ultrasonic horn 50 used when the nonwoven fabric mat 30 is welded, and FIG. 5 is a schematic view showing the welded structure using the ultrasonic horn 50. The ultrasonic horn 50 has a flat pressure surface 51 with a circular tip, and the diameter of the pressure surface 51 is set to 10 mm. Further, a sharp ridge 52 is formed to project in a cross shape on the flat pressure surface 51. The width of the ridge 52 is set to 0.5 mm and the height is set to 1.0 mm. ing.

  Therefore, an aspect in which the nonwoven fabric mat 30 is ultrasonically welded to the back surface of the luggage side trim body 20 using the ultrasonic horn 50 having the flat pressing surface 51 and the sharp ridges 52 set in a cross shape. As shown in FIG. 5, ultrasonic processing was performed on the ultrasonic horn 50 under the conditions of pressure: 0.5 to 0.6 MPa, processing time: 0.1 to 0.5 sec, and frequency: 28 to 40 kHz. In this case, the structure of the welded portion 40 shown in FIG. 3 is obtained.

  In other words, since the nonwoven fabric mat 30 is welded and fixed using the ultrasonic horn 50, an apparatus such as an applicator dedicated to a hot melt adhesive is not required and the work is not necessary compared to a conventional structure using an adhesive. It is environmentally favorable and advantageous in terms of recycling.

  Further, when compared with the conventional example in which the pressing surface of the horn is set to have a complicated uneven shape, the sharp ridges 52 easily bite into the pressing surface of the luggage side trim body 20, so that No irregularities occur, and the appearance performance of the product surface can be kept good. In particular, even when pressed with a low pressure, a strong bonding strength can be obtained. Since a compact air cylinder can be used as a press machine that imparts, and the processing time is short, it is possible to contribute to shortening the work time and increase the productivity. In this example, the nonwoven fabric mat 30 made of a blended nonwoven fabric of high-melting polyester fibers and PP fibers was used. However, if the binder fiber is partly included, the base fiber is a high-melting polyester fiber. Other synthetic fibers and natural fibers can be used. Also, it can be used for felt mixed with some binder fibers.

  Next, FIGS. 6 to 9 show modifications of the first embodiment. First, FIG. 6 is a configuration explanatory view showing an ultrasonic horn in which the shape of the horn is changed, and FIG. 7 is an explanatory view showing a configuration of a welding portion by the ultrasonic horn of FIG.

  6A is a front view of the ultrasonic horn 50A, and FIG. 6B is a view taken in the direction of arrow B in FIG. The ultrasonic horn 50A has a flat pressing surface 51 formed at the tip, and radial pressing ridges 52 projecting from the center to the eight sides. As for the ridges 52, the width dimension is set to 0.5 mm and the height dimension is set to 1.0 mm, as in the above embodiment. Therefore, when the nonwoven fabric mat 30 is welded and fixed to the luggage side trim main body 20 using the ultrasonic horn 50A shown in FIG. 6, the setting area of the ridges 52 is enlarged as compared with the above-described embodiment (cross shape). Therefore, as shown in FIG. 7, there is an advantage that the welding strength of the nonwoven fabric mat 30 can be further strengthened.

  Further, FIG. 8 is an explanatory diagram of a configuration in which the pressure surface shape of the ultrasonic horn 50B is changed, FIG. 8 (a) is a front view of the ultrasonic horn 50B, and FIG. 8 (b) is a view as viewed from arrow C in FIG. Respectively. And FIG. 9 is explanatory drawing which shows the structure of the welding part 40 by the ultrasonic horn 50B. That is, the ultrasonic horn 50B shown in FIG. 8 is formed so as to protrude from the flat pressure surface 51 so that sharp ridges 52 extend in a plurality of rows in the vertical and horizontal directions in a lattice shape. Even in the case where the ridges 52 are set in a lattice shape, the weld portion 40 has an advantage that the proportion of the V-grooves 42 is increased and the weld strength of the nonwoven fabric mat 30 can be enhanced.

  As described above, according to the ultrasonic horns 50, 50A, 50B used in the first embodiment, the cruciform, radial, or grid-like ridges 52 are formed to project on the flat pressure surface 51. The welded portion 40 between the luggage side trim main body 20 and the nonwoven fabric mat 30 is formed with V-grooves 42 corresponding to the patterns of the ridges 52 of the ultrasonic horns 50, 50A, 50B, thereby enhancing the welding strength. can do. The pressure surface 51 of the ultrasonic horns 50, 50A, 50B is circular, but may be oval or square.

  FIGS. 10 and 11 show a second embodiment of the present invention. FIG. 10 is an explanatory diagram showing the configuration of an ultrasonic horn having a changed horn shape. FIG. 10 (a) is a front view of the ultrasonic horn. FIG.10 (b) has each shown the D arrow line view in (a). Moreover, FIG. 11 is explanatory drawing which shows the welding part of the nonwoven fabric mat using the ultrasonic horn shown in FIG. First, in the ultrasonic horn 50C shown in FIG. 10, a sharp ridge 52 is provided along the periphery of the pressure surface 51 with respect to the flat pressure surface 51 at the tip of the horn. In this ultrasonic horn 50C, since it is the structure which forms the protruding item | line 52 along the peripheral edge with respect to the flat pressurization surface 51, use of NC lathe is indispensable in 1st Example, In 2nd Example, since it can process only with a lathe, the processing cost of ultrasonic horn 50C can be reduced.

  Even when this ultrasonic horn 50C is used, as shown in FIG. 11, when the nonwoven fabric mat 30 is joined to the back surface of the luggage side trim main body 20 by ultrasonic processing, the ultrasonic horn 50C is attached to the welded portion 40. When pressed, the protrusion 52 on the periphery of the flat pressure surface 51 bites into the luggage side trim main body 20, and the bonding strength at the welded portion 40 is that the welding effect at the flat welding surface 41 and the anchor effect at the V groove 42 are Since it can be expected, a strong bonding strength of the welded portion 40 can be expected as in the first embodiment, and in ultrasonic processing, the processing time can be shortened and the press machine can be downsized.

  In Example 1 and Example 2 described above, the luggage side trim 10 is shown in which the sound absorption performance is improved by sticking the nonwoven fabric mat 30 to the back surface of the luggage side trim body 20. Naturally, the present invention can be applied not only to sound absorbing parts in the vehicle interior or engine room, but also to fiber mats to be applied to the back surface of the resin panel.

  Moreover, the pressurizing surface 51 of the ultrasonic horn 50 used for the fixing structure of the fiber mat according to the present invention can be changed to an oval shape, a square shape, etc. in addition to a circular shape. Also, the shape of the welded portion 40 and the pattern shape of the V-groove 42 can be arbitrarily set.

It is the perspective view which looked at the luggage side trim which employ | adopted the fixing structure of the fiber mat which concerns on this invention from the back surface side. It is a front view which shows the nonwoven fabric mat affixed on the luggage side trim shown in FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is the (a) front view which shows the structure of 1st Example of the ultrasonic horn used for the fixing structure of the fiber mat which concerns on this invention, (b) It is an A arrow view in (a). It is explanatory drawing which shows the structure of the welding part of the nonwoven fabric mat using the ultrasonic horn shown in FIG. It is the (a) front view which shows the structure of the modification of the ultrasonic horn used for 1st Example of the fixing structure of the fiber mat which concerns on this invention, (b) It is a B arrow view in (a). It is explanatory drawing which shows the structure of the welding part of the nonwoven fabric mat using the ultrasonic horn shown in FIG. It is the (a) front view which shows the structure of the further modification of the ultrasonic horn used for 1st Example of the fixing structure of the fiber mat which concerns on this invention, (b) It is a C arrow line view in (a). It is explanatory drawing which shows the structure of the welding part of the nonwoven fabric mat using the ultrasonic horn shown in FIG. It is the (a) front view which shows the structure of the ultrasonic horn used for 2nd Example of the fixation structure of the fiber mat which concerns on this invention, (b) It is a D arrow line view in (a). It is explanatory drawing which shows the structure of the welding part of the nonwoven fabric mat using the ultrasonic horn shown in FIG. It is explanatory drawing which shows the prior art example which bonded and fixed the sound absorption member to the resin molded product via the adhesive agent. It is explanatory drawing which shows the prior art example which ultrasonic-welds and fixes a nonwoven fabric mat to a resin molded product.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Luggage side trim 20 Luggage side trim main body 30 Nonwoven fabric mat 40 Welding part 41 Flat welding surface 42 V groove 50, 50A, 50B, 50C Ultrasonic horn 51 Pressurizing surface 52 Convex

Claims (8)

The fiber mat (30) is attached to the panel facing surface of the resin molded product (20) attached to the interior surface side of the vehicle body panel, and the fiber mat is subjected to a welding process with an ultrasonic horn (50) for each predetermined spot. In the fixing structure of the fiber mat (30) for fixing (30) to the resin molded product (20),
The welded portion (40) of the fibrous mat (30) includes a flat welded surface (41) against which the flat pressure surface (51) of the ultrasonic horn (50) is pressed, and an ultrasonic horn (50). Each of the fibers of the fibrous mat (30) is composed of V-grooves (42) that bite into the resin molded product (20) by the sharp ridges (52) protruding from the pressing surface (51). A fixing structure of a fibrous mat characterized by that.   The weld portion (40) is composed of a flat weld surface (41) and a V groove (42) set in a cross shape that intersects the flat weld surface (41) vertically and horizontally. The structure for fixing a fibrous mat according to claim 1.   The said welding part (40) is comprised from the flat welding surface (41) and the V-groove (42) extended radially from the center part of this flat welding surface (41). The fixing structure of the fiber mat as described.   The structure for fixing a fibrous mat according to claim 1, wherein the welded portion (40) includes a flat welded surface (41) and a V groove (42) extending in a lattice shape.   The said welding part (40) is provided with the V-groove (42) in the full length of the edge part along the edge part of the flat welding surface (41), or a part of edge part. 2. A fixing structure of the fiber mat as described in 1.   The fiber mat fixing structure according to any one of claims 1 to 5, wherein a groove depth of the V-groove (42) in the welded part (40) is set in a range of 1 mm or less. An ultrasonic horn (50) used for ultrasonic welding the fiber mat (30) to the panel facing surface of the resin molded product (20),
The ultrasonic horn (50) is characterized in that a flat pressing surface (51) is provided with a protruding strip (52) having a sharp tip along a predetermined pattern.   The fiber mat (30) is integrated with the panel facing surface of the resin molded product (20) by the fixing structure of the fiber mat (30) according to any one of claims 1 to 6. Sound absorbing parts for vehicles.

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