JP7116883B2 - Molded article and its manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a molded product and its manufacturing method, and more particularly to a molded product capable of precisely welding a sound absorbing material to a molded product body and its manufacturing method.

Resin boards are known as automotive interior parts such as cargo floor panels (lid panels or luggage boards for automobile luggage compartments) and rear parcel shelves. For example, a molded article in which a fiber sheet is attached to the surface of a hollow molded body (molded article body) manufactured by molding a thermoplastic resin sheet is not only lightweight and excellent in strength, but also has excellent appearance and touch. Therefore, it is widely used as the board.

As a method for producing this type of molded product, a method of integrating a fiber sheet such as a nonwoven fabric at the time of molding a hollow molded product is adopted. A method for manufacturing a hollow molded product to which a fiber sheet (for example, nonwoven fabric) is adhered is disclosed by arranging the fiber sheet and clamping a split mold.

JP-A-2008-55806

By the way, when the manufacturing method described in the aforementioned Patent Document 1 is employed, the fiber sheet is integrated so as to cover the entire surface of the main body of the molded product. Therefore, for example, when a fiber sheet is attached to a part of a molded product body, after molding the molded product body, the fiber sheet can be attached to the molded product body by means of ultrasonic welding or the like. It is done.

At this time, it is difficult to weld the entire surface of the fiber sheet to the main body of the molded product. Usually, the fiber sheet is positioned and fixed to the main body of the molded product by welding the fiber sheet to the main body of the molded product at a plurality of locations. I'm trying Therefore, in welding the fiber sheet to the main body of the molded product, it is necessary to weld the fiber sheet to the main body of the molded product by, for example, pressing an ultrasonic horn against a predetermined location. etc.), there is a problem that it is difficult to grasp the part to be welded because the main body of the molded product under it cannot be seen, and the workability is poor.

In particular, when a sound absorbing material containing a fiber layer is welded and fixed to a molded product, the sound absorbing material includes a fiber layer having a certain thickness in order to ensure the sound absorbing performance. becomes more difficult. A thick sound absorbing material including a fiber layer has an irregular surface rather than a flat surface, like a futon, for example, and it is difficult even for a skilled worker to know where the welding position is.

In addition, at the welded part, for example, a reinforcing part is provided on the main body side of the molded product to increase the strength, and a welding horn or the like is strongly pressed against the welded part to ensure the welded strength. If this happens, especially in the case of a hollow molded product body, sufficient force will not be applied, and there is a risk that the quality of the product will be greatly impaired, such as defective welding.

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned conventional circumstances, and provides a molded product that enables a worker to reliably and quickly recognize a welded portion and that is excellent in workability and quality, and a method for manufacturing the same. intended to

In order to achieve the above-mentioned object, the molded product of the present invention is a molded product in which a sound absorbing material including a fiber layer is welded and fixed to a molded product body made of resin, the sound absorbing material has a and a marker for welding position alignment is formed as the compressed portion in the vicinity of the welding position of the sound absorbing material.

Further, in the method for producing a molded product of the present invention, a compressed portion is formed by compression along the outer periphery of a sound absorbing material including a fiber layer, and at the same time, a marker is formed as a compressed portion in the vicinity of the welding position of the sound absorbing material, and a molded product body is formed. When the sound absorbing material is welded and fixed to the molded product body, the marker is used for positioning, and the sound absorbing material is welded and fixed to the molded product body.

In the molded product and the manufacturing method thereof of the present invention, the sound absorbing material is provided with a marker indicating the welding position. This is obvious, the workability is improved, and the occurrence of poor welding is reliably suppressed.

According to the present invention, it is possible to provide a molded product that is excellent in workability in manufacturing, and furthermore, it is possible to provide a highly reliable molded product that does not deteriorate in quality due to misalignment of the welding position. is.

It is a schematic plan view of a molded article. It is a figure which shows schematic structure of the molding apparatus for shape|molding a molded product main body. FIG. 4 is a schematic plan view showing an example of markers formed on a sound absorbing material; FIG. 5 is a schematic plan view showing another example of markers formed on a sound absorbing material; FIG. 9 is a schematic plan view showing still another example of markers formed on a sound absorbing material;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a molded article to which the present invention is applied and a method for manufacturing the same will be described in detail below with reference to the drawings.

The molded product 1 of this embodiment is a board installed in the luggage compartment of an automobile, and as shown in FIG. Material 3 is attached. The sound absorbing material 3 is welded and fixed to the molded product main body 2 at a plurality of welded portions Y. As shown in FIG.

The molded article main body 2 is a resin panel (hollow molded body) having a so-called hollow double-wall structure here, but is not limited to this. Further, a reinforcing material may be embedded in the hollow portion of the molded product main body 2, or reinforcing ribs may be formed on the surface wall or the back surface wall. It is also possible to adopt a reinforcing structure in which an inner rib is formed in the hollow portion to extend from the back wall to the front wall. Also, the molded article main body 2 may be a so-called sandwich panel in which a core material is arranged inside a double-walled structure.

The thermoplastic plastic material constituting the molded article body 2 is arbitrary, but examples include polyethylene resin, polypropylene resin, ethylene-vinyl acetate copolymer, vinyl chloride resin, ABS resin (acrylonitrile-styrene-butadiene resins), polyamide resins, polystyrene resins, polyester resins, and engineering plastics such as polycarbonates and modified polyphenylene ethers.

Next, a molding apparatus for such a molded product body 2 will be described. As shown in FIG. 2, a molding device 10 for a molded product body 2, which is a hollow molded panel, has an extrusion device 12 and a mold clamping device 14 arranged below the extrusion device 12. The melted resin sheet P is sent to the mold clamping device 14, and the mold clamping device 14 molds the melted resin sheet P. As shown in FIG.

The extruder 12 is of a conventionally known type, and a detailed description thereof will be omitted. It has a hydraulic motor 20, an accumulator 22 whose inside communicates with the cylinder 18, and a plunger 24 provided in the accumulator 22, and the resin pellets thrown from the hopper 16 are pushed into the screw by the hydraulic motor 20 in the cylinder 18. The molten resin is melted and kneaded by the rotation of , and the molten resin is transferred to the accumulator chamber 22 and stored in a certain amount. of continuous resin sheet P is extruded, fed downward while being pinched by a pair of rollers 30 arranged at intervals, and suspended between split molds 32 . As a result, the resin sheet P is arranged between the split molds 32 with a uniform thickness in the vertical direction (extrusion direction).

Like the extrusion device 12, the mold clamping device 14 is also of a conventionally known type, and although detailed description thereof will be omitted, two split-type molds 32A, B and a molten resin It has a mold driving device for moving between an open position and a closed position in a direction substantially perpendicular to the feeding direction of the sheet P.

The two split-type molds 32A, B are provided with recesses 119A, 119B as cavities according to the molding shapes of the resin sheets P1, P2.

In each of the two split molds 32A,B, a pinch-off portion 118 is formed around the cavity, the pinch-off portion 118 being annularly formed around the cavity and directed toward the opposing mold 32A,B. protrude. As a result, when clamping the two split-type molds 32A, B, the tip portions of the respective pinch-off portions 118 come into contact with each other, and the two molten resin sheets P1, P2 form a parting line on their peripheral edges. It is welded so that PL is formed.

The mold 33A is slidably fitted on the outer periphery of the mold 32A in a sealed state, and the mold 33A is relatively movable with respect to the mold 32A by a mold moving device (not shown). . The mold 33A can come into contact with the side surface of the resin sheet P1 arranged between the molds 32A and 32B by protruding toward the mold 32B with respect to the mold 32A. Although illustration is omitted, similarly, a mold is provided on the outer periphery of the mold 32B, and the mold is arranged between the molds 32A and 32B by projecting toward the mold 32A. It is possible to abut on the side surface of the resin sheet P2.

Vacuum suction chambers are provided inside the split molds 32A and 32B, and the vacuum suction chambers communicate with the cavities through the suction holes. The resin sheets P1 and P2 are adsorbed and shaped into the cavity shapes of the split molds 32A and 32B.

For molding, first, a predetermined amount of melt-kneaded resin is stored in the accumulator 22, and the stored thermoplastic resin is intermittently extruded at a predetermined extrusion rate per unit time from extrusion slits 34 provided at predetermined intervals in the T-die 28. push out. Next, the resin sheets P1 and P2 having a uniform thickness in the extrusion direction are arranged between the split molds 32A and 32B arranged below the pair of rollers 30. As shown in FIG.

Next, the resin sheets P1 and P2 are pressed against the cavities of the molds 32A and 32B by suction from the vacuum suction chambers provided in the molds 32A and 32B through the suction holes, and the resin sheets P1 and P2 are shaped into the cavities. shape the Then, while sucking and holding the resin sheets P1 and P2, the molds 32A and 32B are moved toward each other until the annular pinch-off portions 118A and 118B come into contact with each other, and the molds are clamped.

The molded product main body 2 is removed from the molds 32A and 32B, and the sound absorbing material 3 is adhered and fixed to a predetermined position of the molded product main body 2 by welding, but the welding position is difficult for the operator to understand. Therefore, in this embodiment, a marker is attached to the sound absorbing material 3 so that the operator can visually grasp the approximate welding position.

The application of markers to the sound absorbing material 3 will be described below.

Any material such as nonwoven fabric or woven fabric is used for the sound absorbing material 3 depending on the required functions. Specific examples include natural fibers such as cotton, hemp, wool, and silk, regenerated fibers such as viscose rayon and cuprammonium rayon, semi-synthetic fibers such as acetate and rayon, nylon, polyester, acrylic, vinylon, and polypropylene. , synthetic fibers such as polyurethane, and fiber sheets such as knitted fabrics, woven fabrics, and non-woven fabrics obtained by processing these blended fibers.

In particular, as the sound absorbing material 3 having excellent sound absorbing performance, it is preferable to have a fiber layer having a certain thickness and cover it with gauze-like woven fabric. As the sound absorbing material 3, a commercially available one can be used, and for example, Thinsulate (trade name) manufactured by 3M is suitable. Thinsulate, a trade name manufactured by 3M Company, is known as a sound-absorbing and heat-insulating material, and includes microfibers produced by the meltblown method and non-woven fabrics containing short fibers having a fiber diameter of 20 to 30 μm.

When using the sound absorbing material 3 including the fiber layer as described above, the outer peripheral portion of the sound absorbing material 3 is compressed for the purpose of preventing fraying of fibers in the peripheral portion. That is, along the outer circumference of the sound absorbing material 3, a compressed portion C is formed by compression. As a result, fraying of fibers, etc., in the outer peripheral portion of the sound absorbing material 3 can be eliminated.

In this embodiment, this compression is used to form a marker. That is, as shown in FIG. 3, when compressing the outer peripheral portion of the sound absorbing material 3, the marker M1 is simultaneously formed as a compressed portion by extending the compressed portion C on the outer periphery.

The compressed portion C obtained by compressing and crushing the sound absorbing material 3 can be visually distinguished from other portions, and the marker M1 formed by compression similarly to the compressed portion C can also be distinguished from other portions. and can be visually recognized as a so-called marker.

The shape of the marker M1 is a part of an arc of a circle centering on each welded portion Y. In the example of FIG. It is formed by compression so as to extend the portion C. Therefore, by looking at the circular arc-shaped marker M1, the operator can see that the vicinity of the center is the welding point, and by pressing an ultrasonic horn, for example, against this portion, the welding operation can be performed quickly. . Moreover, in welding, the welding can be reliably performed without any positional deviation in the pressing position of the ultrasonic horn.

The shape of the marker formed on the sound absorbing material 3 is not limited to the example shown in FIG. 3. For example, as shown in FIG. is also possible. Furthermore, as shown in FIG. 5, a combination of a marker M1 formed by extending the compressed portion C and an arcuate marker M2 formed apart from the compressed portion C may be used.

However, when the marker M2 is formed in the area inside the compressed portion C of the sound absorbing material 3, the configuration of the pressing machine for forming the marker M2 at the same time as the compressing portion C becomes complicated. In the region inside C, the fiber layer thickened for sound absorption is crushed, and there is a concern that the sound absorption performance is lowered. If the marker M2 is formed as a compressed portion, the thickness of the peripheral portion will also be reduced, which is not preferable in terms of sound absorption performance.

Therefore, among the examples shown in FIGS. 3 to 5, the example shown in FIG. 3 is preferred. In the example shown in FIG. 3, the formation of the marker M1 only slightly extends the compressed portion C on the outer periphery of the sound absorbing material 3, so that it hardly affects the sound absorbing performance.

The shape of the marker is not limited to these examples, and may be any shape as long as the operator can grasp the welding position.

As described above, by forming markers corresponding to the welding positions on the sound absorbing material 3, the operator can quickly identify the welding positions, and the productivity of the molded product 1 can be greatly improved. can. In addition, since it is possible to avoid positional deviation during welding, sufficient force can be applied to an ultrasonic horn or the like used for welding. It is possible to

Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments, and that various modifications are possible without departing from the gist of the present invention. For example, in the previous embodiment, ultrasonic welding using an ultrasonic horn was described as an example, but other welding methods such as thermal welding are similarly applicable. Also, in the previous embodiment, the sound absorbing material had a compressed portion along the entire circumference of the outer circumference, but the sound absorbing material may have an uncompressed area in a part of the outer circumference. .

1 Molded product 2 Molded product body 3 Sound absorbing material 10 Molding device C Compression parts M1, M2 Marker

Claims (5)

A molded product in which a sound absorbing material including a fiber layer is welded and fixed to a resin molded product body,
The sound absorbing material has a compressed portion compressed along the outer periphery,
A molded product, wherein a marker for welding position alignment is formed as a compressed portion in the vicinity of the welding position of the sound absorbing material. 2. The molded article according to claim 1, wherein the shape of said marker is at least a part of an arc of a circle centered on the welding position. 3. The molded article according to claim 1, wherein said marker is formed in a shape extending from a compressed portion compressed along said outer circumference. 4. The molded product according to any one of claims 1 to 3, wherein the molded product main body is mainly composed of a resin-made hollow molded body. Forming a compressed portion by compression along the outer periphery of the sound absorbing material including the fiber layer, and simultaneously forming a marker as a compressed portion near the welding position of the sound absorbing material,
A method for manufacturing a molded product, characterized in that when the sound absorbing material is welded and fixed to the molded product body, the marker is used for positioning, and the sound absorbing material is welded and fixed to the molded product body.

Images