KR102459137B1 - Manufacturing method for car interior components - Google Patents

Abstract

The present invention relates to a method for manufacturing an automobile interior material, and the method for manufacturing an automobile interior material according to the present invention is a V-groove having a depth of 0.25 to 0.35 mm and an angle of 40 to 60 degrees at a position where a real stitch of the skin to be used is to be sewn. When forming a real stitch line, regardless of the type of sewing machine, the stitch thread is naturally seated on the V-groove line of the skin, so that the stitch line is beautifully and neatly aligned to improve the aesthetic quality of the real stitch. Even in the case of a curved surface, there is little directional distortion, and since the real stitch is seated on the V-groove line of the skin, the stitch is prevented from sticking out too much, thereby reducing the risk of damage to the real stitch and improving the stain resistance.

Description

Manufacturing method of automobile interior materials

The present invention relates to a method for manufacturing an automobile interior material, and more particularly, a skin for automobile interior material in which a V-groove line having a depth of 0.25 to 0.35 mm and an angle of 45 to 60 degrees is formed at a position where a real stitch is to be sewn. By using, as well as improving the aesthetic quality of the real stitch, it relates to a method of manufacturing a vehicle interior material that can reduce the risk of damage and improve the stain resistance of the real stitch.

In general, various interior materials such as instrument panels, glove boxes, consoles, lower covers, pillars, door interior panels, and airbag cover panels of automobiles are injection molded by melting synthetic resin.

In the development of automobile manufacturing technology, the importance of design that can satisfy the sensibility of consumers as well as the improvement of mechanical performance has been greatly emphasized.

In accordance with the advancement of automobile interior materials, in-mold graining (IMG), which enables surface treatment of luxurious interior materials by using an electric pole mold with patterns and fake stitches with sophisticated natural leather textures. Molding of interior materials is becoming common.

This IMG molding is made by bonding a skin having a natural leather texture and pattern to an injection-molded core in a mold.

In recent years, various attempts have been made to imitate the luxurious aesthetics of adding real stitches to natural leather by hand in some supercars and expensive cars, and to apply real stitches that can give these luxurious textures and aesthetics to commercial mass-produced cars. is in progress

In general, the interior material with real stitching is manufactured by molding a soft skin with a luxurious and soft pattern with an IMG mold, sewing the real stitch on the molded skin, and then joining the skin on which the real stitch is sewn and the hard core. , A foaming resin is usually interposed between the skin and the core.

In general, the process of forming a real stitch on such a skin is as if folding the ends of two skins so that a fold line is formed between the butt bars formed, and the skins on both sides of the fold line are sewn together, and from the fold line It is formed to express the same luxurious and natural aesthetics and textures as if fixed by sewing real leather by separately sewing stitch lines at positions slightly spaced apart on one side or both sides.

Sewing machines that sew real stitches on these skins can be broadly divided into lock-type sewing machines and chain-type sewing machines. According to the structure of the sewing machine, depending on the structure of the lower thread, the lock type stitches are formed in an oblique line, and the arrangement of the threads is irregular, so the stitch quality is inferior, and the chain Although the type is formed in a straight line, it is a very expensive equipment, and no matter what type of sewing machine is used, the direction is distorted when sewing in a three-dimensional curved shape or flat round shape, and the stitch thread protrudes too much, so the protruding stitch is not damaged or worn out. As well as being easy, there is a problem in that contaminants are easily attached.

Typical prior art related to an automobile interior material in which a stitch is formed may include the following.

Registered Patent Publication No. 10-2076817 (registered on Feb. 26, 2020) proposes a method for manufacturing an electric pole mold capable of forming stitches on a finished sheet for a vehicle, but this is for manufacturing a finished sheet having fake stitches, not real stitches. It relates to a method for manufacturing an electroforming mold.

In addition, Patent Publication No. 10-1773138 (registered on Aug. 24, 2017) discloses the steps of forming real stitches on both sides of the stitch line of the skin pad using a sewing device and the real skin pad portion corresponding to the fixing hole of the substrate core. Although a method of manufacturing an interior material for a vehicle including the step of forming a through-hole by piercing is presented, this method only forms real stitches in a conventional manner and has nothing to do with the quality or contamination resistance of the real stitch lines.

Registered Patent Publication No. 10-2165285 (registered on 10.06.2020) proposes an insert injection method of an interior material including forming a stitch line on the skin using a sewing device, but this method is a skin with a stitch line formed therein. It is only related to insert injection using

In addition, Patent Registration No. 10-1264177 (registered on May 8, 2013) discloses a skin manufactured by a powder slush molding (PSM) method; a fold line recessed from the upper surface of the skin to appear as if the skin is actually folded; a first pad coupled to a lower surface of the skin to give the skin a sense of volume; a sewing line formed by actually sewing the skin and the first pad; a second pad coupled to a lower surface of the first pad so as to block a sewing hole formed through the skin and the first pad according to the formation of the sewing line; Foam formed on the lower side of the skin by foaming the foam; And a skin structure for an automobile interior material having a double sealing structure, characterized in that it comprises a core disposed on the lower side of the foam, but similarly, it is only that a real stitch is formed, and the quality of the stitch line or resistance It has absolutely nothing to do with pollution.

Registered Patent Publication No. 10-1264177 (Registered on May 8, 2013) Registered Patent Publication No. 10-1773138 (Registered on August 24, 2017) Registered Patent Publication No. 10-2165285 (Registered on 10.06.2020)

Therefore, it is an object of the present invention to improve the aesthetic quality of real stitch because the stitch line can be formed beautifully and neatly regardless of the type of sewing machine when forming the real stitch line, reduce the risk of damage of the real stitch and stain resistance An object of the present invention is to provide a method for manufacturing an automobile interior material using a skin for automobile interior material that can be improved.

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The above-described object of the present invention is a method for manufacturing an automobile interior material having a real stitch including a model processing step, a N ping step, a duplication step, an electroforming step, a skin forming step, a sewing step, and a skin bonding step In the above-described model processing step, in addition to the recess for forming a fold line, offset processing of a V-groove line for forming a single or double stitch line on one or both sides adjacent thereto is offset, and the natural leather texture in the N ping step And a PVC sheet with a thickness of 0.5 to 0.7 mm on which a pattern is formed is Ned on the model, and the PVC sheet part located on the V groove line of the model is pressed with a tool having a sharp edge to form a V groove line, By forming a protruding line having a '∧' shape in cross section on the surface of the nickel shell on which the natural leather texture and pattern electroforming in the above step are formed, the skin vacuum-formed in the above skin forming step is the natural leather texture and pattern. In addition, a V-groove line with a depth of 0.25 to 0.35 mm and an angle of 40 to 60 degrees is formed at the position where the real stitch is to be sewn, and natural leather texture and After obtaining a skin made of TPO, TPU, or PVC fabric with a V-groove line formed while the pattern is positively formed, the real stitch is sewn so that the stitch thread is seated and aligned on the V-groove line of the skin in the above sewing step. It can be smoothly achieved by a method of manufacturing an automobile interior material, characterized in that.

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According to the manufacturing method of the automobile interior material according to the present invention as described above, when forming the real stitch line, the stitch thread is naturally seated on the V groove line of the skin regardless of the type of sewing machine, so that the stitch line is beautifully and neatly aligned. It is possible to improve the aesthetic quality of the real stitch, and there is not much directional distortion even in the case of a curved shape, and since the real stitch seated on the V-groove line of the skin does not stand out too much, the risk of damage to the real stitch is reduced and the stain resistance is improved.

1 is a schematic cross-sectional view of a model applied to a method for manufacturing an automobile interior material according to the present invention, and a PVC sheet that is N-pinned thereto.
FIG. 2 is a schematic cross-sectional view showing in advance the position where the real stitch is seated on the V-groove line of the skin on which the V-groove line is formed, which is used in the method for manufacturing an automobile interior material according to the present invention in FIG. 1 .
3 is a plan view of a test specimen used in Examples.
4 is an enlarged view showing the real stitch according to the manufacturing method of the vehicle interior material according to the present invention.
5 is an enlarged view showing a real stitch according to a conventional manufacturing method using a conventional skin.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a schematic cross-sectional view of a model 7 applied to a method for manufacturing an automobile interior material according to the present invention and a PVC sheet 6 that is N pinged thereto, and FIG. 2 is a V used in the method for manufacturing an automobile interior material of the present invention. 1 is a virtual schematic cross-sectional view showing the position where the real stitch 3 is seated on the V groove line 2 of the skin 1 on which the groove line 2 is formed, and FIG. 3 is a test specimen used in the embodiment. It is a plan view, and FIG. 4 is an enlarged view showing the real stitch 3 sewn to the skin 1 used in the method for manufacturing an automobile interior material according to the present invention, which will be referred to together for convenience of description.

The skin 1 for automobile interior material applied to the manufacturing method of the present invention has a V-groove line 2 having a depth of 0.25 to 0.35 mm and an angle of 40 to 60 degrees in advance at a position where the real stitch 3 is to be sewn.

The above-mentioned automobile interior skin 1 is made of thermoplastic polyurethane (TPU), thermoplastic polyolefin (TPU), or polyvinyl chloride (PVC), and the surface thereof has a pattern of natural leather texture.

The process of forming the real stitch 3 on the skin 1 for automobile interior material described above is like the fold line 4 formed between the butt bars 5 when the ends of the two skins are folded and abutted to each other. A real stitch (3) along the V-groove line (2) formed at a position slightly spaced apart on one side or both sides from the fold line (4) while sewing the skins on both sides of the fold line (4) to each other. By separately sewing and forming, it is formed to express the same luxurious and natural aesthetics and textures as if it was fixed by sewing real leather.

The method for manufacturing an automobile interior material according to the present invention includes the following steps.

(1) Design and model processing steps:

A V-groove line (Fig. 2 and Fig. 2) on the surface of the skin for automobile interior material according to the present invention (see reference number 1 in Figs. 2 and 4) so that the real stitch (refer to reference numeral 3 in Figs. 4), a V-groove offset line 7b is formed on the surface of the model (deck mold) 7 as shown in FIG. 1 .

The concave groove 7a for forming the fold line 4 in FIG. 1 is known in the art.

(2) Nping step:

As shown in FIG. 1, the PVC sheet 6 formed with a natural leather texture and pattern (embossing pattern) of 0.5 to 0.7 mm, specifically 0.6 mm thick, on the surface of the model 7 is pinged and The PVC sheet 6 corresponding to the V-groove offset line 7b of the above-described model 7 is pressed with a tool having an edge that is sharp or has no risk of cutting, so that the V-groove line (2) on the PVC sheet (6) to form this

(3) (model) cloning step (not shown):

After replicating the N-pinned model (7) in the first negative state using silicon, make the same positive model as the original model (7) using epoxy resin on the silicon model.

(4) silver film coating step (not shown):

A thin layer of silver is coated by silver mirror reaction so that the surface of the replicated epoxy model (hereafter, mandrel) can be energized.

(5) electroforming (nickel plating) step (not shown):

The mandrel coated with a silver film is immersed in a nickel sulfamic acid bath, and DC electricity of 0.6~3A is supplied to galvanize the nickel until the thickness of the nickel plating becomes 4~5mm.

On the inner surface of the electro-poled nickel shell, the natural leather texture and pattern are negatively formed, while a protruding line with a ‘∧’ cross-section is formed.

(6) demolding step (not shown):

When the nickel plating goes up to a thickness of 4-5 mm, the mandrel is put in a heating furnace and heated to 300-400°C to remove the epoxy mandrel and separate the manufactured nickel shell.

(7) Jeonju mold assembly step (not shown):

Assemble the vacuum mold in which the upper and lower molds are combined by fastening the separated nickel shell (electroforming mold) to the mold box and manufacturing the lower mold.

(8) skin forming step (not shown):

After mounting the vacuum mold assembled as described above in the vacuum molding machine, vacuum molding is performed to form a natural leather texture and pattern positively on the surface, while the V-groove line is formed as a TPO, TPU, or PVC fabric according to the present invention. get a dragon skin

(9) Sewing steps:

Using a sewing machine on the molded surface of the car interior skin (1) according to the present invention, a single or double real stitch (3) is sewn to be seated on the V-groove line (2) part based on the fold line (4) of FIG. do.

At this time, the stitch thread is naturally seated on the V-groove line (2) machined on the surface of the skin (1) for interior materials for automobiles according to the present invention to guide the arrangement of the real stitch (3), so that it is beautifully and neatly aligned to improve aesthetic quality Even in the case of a curved surface, there is not much directional distortion, and since the real stitch 3 is seated on the V-groove line 2, it offsets the excessive prominence of the real stitch 3, thereby reducing the risk of damage and contamination resistance. This is improved.

(10) bonding, trimming, and Nping steps (not shown):

After mounting the sewn skin (1) for automobile interior material according to the present invention to a compression mold, compression bonding using a substrate (interior material core), trimming the outer edge of the product, and wrapping the outer end of the vehicle manufactures interior parts.

Example: Preparation of Specimen

Specimens were prepared using steps (1) to (10) as described above.

The size of the produced specimen is 150mm x 150mm, and the center is round.

Real stitch sewing was performed using a skin that formed a single real stitch V groove line at 2/3 of the specimen.

The sewing machine used at this time is a lock-type industrial sewing machine in which the thread is sewn at an oblique angle of about 5 to 10 degrees, and the applied thread is 420 denier three-ply yarn.

4 shows the specimen.

Test example: V-groove line design for quality and stain resistance improvement evaluation of real stitch

In order to evaluate the emotional quality through the alignment state (quality) of the real stitch and the prominence of the real stitch, a specimen using a skin having a V-groove line having various depths and angles was produced and evaluated, and the results are shown in Table 1 and Table 2 shows each.

From the above results, it was possible to confirm whether the directionality and prominence of the thread were improved according to the depth and angle of the V-groove line of the skin in FIG. 4 (see FIG. 2). It was found that the best effect was found between 0.25 and 0.35 mm, and the angle between 40 and 60 degrees.

These results can be clearly confirmed from FIG. 5 showing the case of the present invention in which the V-groove line is formed on the skin in comparison with FIG. 5 showing the conventional case in which the skin does not have a V-groove line.

Although the present invention has been described in detail with reference to preferred embodiments according to the present invention, this is only for illustrating the present invention and is not intended to limit the present invention, and various changes and modifications can be made without departing from the scope of the present invention by those skilled in the art. It should be noted that, of course, this is also within the scope of the present invention.

1: Skin for automobile interior material according to the present invention
2: V home line 3: Real stitch
4: fold line 5: cross seam
6: PVC sheet 7: model
7a: concave groove 7b: V groove offset line

Claims (5)

delete delete In the manufacturing method of a car interior material in which a real stitch is formed, comprising a model processing step, a Nping step, a duplication step, an electroforming step, a skin forming step, a sewing step, and a skin bonding step,
In the model processing step, in addition to the recess for forming a fold line, offset machining a V-groove line for forming a single or double stitch line on one side or both sides parallel to and adjacent to the recess for forming a fold line,
In the above-mentioned n-ping step, a PVC sheet with a thickness of 0.5 to 0.7 mm on which a natural leather texture and pattern are formed is n-ped to the model, and the PVC sheet part located at the V-groove line of the model is pressed with a tool having a sharp edge to make a V groove. forming a line,
By forming a protruding line having a '∧' shape in cross section on the surface of the nickel shell on which the natural leather texture and pattern to be electroformed in the electroforming step are formed, the skin vacuum-formed in the skin forming step has a natural leather texture And in addition to having a pattern, a real stitch (real stitch) to a depth of 0.25 to 0.35 mm at a position to be sewn and to form a V-groove line of an angle of 40 to 60 degrees,
After obtaining a skin made of TPO, TPU, or PVC fabric with a V-groove line formed while the natural leather texture and pattern are positively formed on the surface by vacuum forming in the above skin forming step,
In the above sewing step, the real stitch is sewn so that the stitch thread is seated and aligned on the V groove line of the skin.
A method for manufacturing automobile interior materials. delete delete

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