JP3933021B2 - Interior material for automobile and method for manufacturing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automobile interior material covering an airbag device and a method for manufacturing the same.
[0002]
[Prior art]
An air bag device that protects an occupant from an impact generated when a vehicle collides is normally installed inside an interior material that covers the vehicle interior so that the vehicle cannot be seen from the outside.
[0003]
For this reason, the inner surface of the interior material located in the inflating direction of the airbag is formed with a planned tearing groove called a tear line that breaks when the airbag is inflated so as not to hinder the inflation and deployment of the airbag. In the case of an interior material whose surface is covered with a skin layer made of a soft resin sheet in order to enhance the decorative effect, there are problems such as the skin layer hindering the breakage of the planned cleavage line.
[0004]
In order to improve such a problem, for example, Patent Documents 1 to 3 propose interior materials in which a large number of small holes are provided in the skin layer so that the skin layer does not hinder the breakage of the planned cleavage line.
[0005]
[Patent Document 1]
Japanese Utility Model Publication No. 51-1932 (FIGS. 3 to 5)
[Patent Document 2]
JP-A-9-86321 (Page (4), FIGS. 1 and 2)
[Patent Document 3]
JP 2000-16216 A (page (3) -page (6))
[0006]
The interior material (airbag cover) described in Patent Document 1 is a material in which a through hole or a bag hole is formed in a perforation along a fracture line in an interior material formed of a single resin, and the airbag is inflated. When this is done, the interior material is configured to be broken through the through hole or the bag hole.
[0007]
In addition, the interior material (airbag cover) described in Patent Document 2 is provided with an interior material made of a thermoplastic resin, in which a large number of holes are intermittently provided along the fracture line, and the inner surface of the hole is protruded by heat treatment. Since the opening portion of the hole is not conspicuous by the convex portion, the design property is improved.
[0008]
Furthermore, the interior material (instrument panel) described in Patent Document 3 has a large number of holes regularly formed on the entire surface of the skin layer that covers the surface of the base material. The skin layer is configured to be broken from a hole in the vicinity of the planned portion.
[0009]
[Problems to be solved by the invention]
However, in the case of the interior material described in Patent Document 1, since a large number of holes appear along the fracture line on the surface of the interior material, it does not look good, and in the case of an interior material made of a single resin, Since it is formed, the small holes formed in the interior material are deformed and appear to be uneven, which causes problems such as poor appearance.
[0010]
Further, in the case of the interior material described in Patent Document 2, after forming a large number of holes in the interior material, an operation of forming convex portions at the openings of the large number of holes by heat treatment is performed. In addition, the work efficiency is poor, and when the interior material is heated to a high temperature, uneven color occurs on the surface of the interior material, and the opening edge of the hole sags due to heat. There are problems such as getting worse.
[0011]
On the other hand, the interior material described in Patent Document 3 has a structure in which a large number of holes are formed on the entire surface of the skin layer, and the skin layer breaks from the holes in the vicinity of the planned cleavage when the planned cleavage of the substrate breaks. Therefore, when the skin layer is formed of a material that is particularly difficult to cut, the skin layer may not be broken into a desired shape, resulting in problems such as lack of reliability.
[0012]
Moreover, since the holes formed on the entire surface of the skin layer uniformize the decoration effect, there is a problem that a high-class feeling cannot be obtained in the interior material.
[0013]
The present invention has been made to improve such conventional problems, and it is possible to surely break the skin layer from the groove to be cut formed in the base material, and to have a good appearance. Is intended to provide.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, an interior material for automobiles of the present invention comprises an interior material body that covers an airbag device, comprising a base material formed of a hard resin, and a skin layer that covers the surface of the base material, and An automotive interior material in which a groove to be ruptured when an airbag is inflated is formed on an inner surface of a base material, and a plurality of holes are formed in the skin layer along the planned tear groove, and the base material is made of a hard resin. When molding is performed, hard resin is allowed to flow into a part of the hole.
[0015]
With the above configuration, when the airbag is inflated by an impact when the automobile collides, and the base material is broken from the planned cleavage groove, the skin layer is broken from the plurality of holes formed along the planned cleavage groove. In addition, the airbag can be inflated and deployed instantly, and even when using a material that is difficult to break for the skin layer, the skin layer can be reliably broken from the plurality of holes formed along the planned cleavage groove, The degree of freedom of materials that can be used for the skin layer is increased, which makes it possible to easily obtain interior materials rich in luxury.
[0016]
In order to achieve the above-mentioned object, the automotive interior material of the present invention is formed by through-holes penetrating the front and back surfaces of the skin layer.
[0017]
According to the above configuration, since the resin that has entered the hole closes the opening of the hole that appears on the surface of the skin layer, the hole that appears on the surface of the skin layer even if a plurality of holes are formed along the planned cleavage groove As a result, the appearance of the interior material is improved, and the resin that has entered the hole prevents the deformation of the hole, so that the appearance of the interior material over time can be stabilized.
[0018]
In order to achieve the above-mentioned object, the automotive interior material of the present invention is formed by blind holes in which the openings do not appear on the surface of the skin layer.
[0019]
According to the above configuration, since the resin that has entered the hole does not appear on the surface of the skin layer, resins having different colors can be used for the base material and the skin layer, and the resin that has entered the hole has a hole. In order to prevent the deformation of the interior material, it is possible to stabilize the appearance shape of the interior material over time.
[0020]
In order to achieve the above object, an automobile interior material manufacturing method according to the present invention comprises an interior material body that covers an airbag device, comprising a base material formed of a hard resin and a skin layer that covers the surface of the base material. And a method of manufacturing an interior material for an automobile in which an inner surface of a base material is formed with a planned tearing groove that breaks when the airbag is inflated, and a plurality of holes are formed at positions that match the planned tearing groove formed on the base material. when the formed skin layer, was set at a predetermined position in the mold for molding the substrate, and forming the implantation to the substrate a molten hard resin on the back side of the skin layer in this state, one bore Hard resin is allowed to flow into the part .
[0021]
By the method, when molding the resin substrate, for closing holes and enters the portion of the plurality of holes resin is formed on the skin layer, even when a plurality of holes along the cleavage scheduled groove Holes appearing on the surface of the skin layer are less noticeable, which improves the appearance of the interior material and prevents the resin from entering the holes from deforming the hole, thus stabilizing the appearance of the interior material over time. Can be made.
[0022]
In order to achieve the above object, the method for manufacturing an automobile interior material according to the present invention is such that after the interior material body is formed, a groove to be cleaved is cut on the inner surface of the base material.
[0023]
According to the above-described method, molding defects such as color unevenness and sink marks do not occur on the surface of the interior material, so that an interior material with a good appearance can be obtained and the occurrence of defective products can be reduced.
[0024]
In order to achieve the above object, the method for manufacturing an interior material for automobiles of the present invention is such that when the interior material body is molded, a groove to be cleaved is integrally formed on the inner surface of the base material.
[0025]
According to the above method, the cleavage planned groove can be formed at the time of forming the base material, and therefore, the number of man-hours can be reduced as compared with the case of cutting the cleavage planned groove by post-processing.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described in detail with reference to the drawings.
[0027]
FIG. 1 is a partially cutaway perspective view of an interior material covering an airbag device, FIG. 2 is a plan view of the interior material surface, FIG. 3 is a plan view of a groove to be cleaved formed on the inner surface of the interior material, and FIG. FIG. 5 is an enlarged view in a circle B in FIG. 4.
[0028]
An interior material body 1 shown in FIG. 1 covers, for example, an airbag device 2 installed in front of a passenger seat (not shown), and an instrument panel (not shown) made of a hard resin such as polypropylene (PP) resin. ) And a skin layer 1b covering the surface of the substrate 1a.
[0029]
A case 2a of the airbag device 2 is provided inside the base material 1a, and an airbag folded in the case 2a is accommodated. In a retainer attached to the bottom of the case 2a, an air bag is accommodated. An inflator (both not shown) for inflating the bag is accommodated.
[0030]
On the upper surface of the case 2a of the airbag device 2, a door body 2b welded to the inner surface of the base material 1a of the interior material body 1 is provided integrally with the case 2a.
[0031]
The door body 2b is formed of two members divided substantially from the center, and a thin hinge portion 2c is formed on the side of the connecting portion of each door body 2b and the case 2a, and is accommodated in the case 2a. Each door 2b is pushed and opened in the direction of inflation of the airbag around the hinge 2c by the pressure when the airbag is inflated.
[0032]
On the inner surface of the base material 1a to which the upper surface of the door body 2b is welded, a planned cleavage groove 3 is formed by cutting after forming the base material 1a.
[0033]
As shown in FIG. 3, the planned cleavage groove 3 includes two upper and lower horizontal line portions 3 a and 3 b provided along the hinge portion 2 c of the door body 2 b, and 1 provided along the dividing line of the door body 2 b. A cutting tool such as an end mill is formed by two vertical line portions 3d and 3e that vertically connect both ends of the horizontal line portion 3c and the upper and lower horizontal line portions 3a and 3b. Thus, the bottom thickness (remaining thickness) is 0.3 to 2.5 mm, preferably 0.8 mm (including the skin thickness).
[0034]
On the other hand, the skin layer 1b that covers the surface of the base material 1a is formed of a soft resin sheet having a sheet thickness of about 0.3 to 1.5 mm, and is intended to be cleaved groove 3 formed by post-processing on the inner surface of the base material 1a. A plurality of holes 4 are previously drilled along the planned cleavage grooves 3 at positions that coincide with.
[0035]
These holes 4 have a hole diameter of 0.05 to 2.0 mm, preferably 0.2 to 0.3 mm, and the pitch between the holes 4 is 0.1 to 5.0 mm, preferably 0.5 to 1.0 mm. It is formed by a hole processing means (not shown) such as a processing blade, a needle, or a laser having a plurality of protrusions matching the hole diameter and hole pitch.
[0036]
Next, the manufacturing method of the interior material configured as described above and the operation during use will be described.
[0037]
When manufacturing the interior material body 1, if the soft resin sheet serving as the skin layer 1 b is cut into a predetermined size, a hole 4 is formed at a position that matches the planned cleavage groove 3 formed on the inner surface of the substrate 1 a. Set up.
[0038]
These holes 4 are drilled in an H shape as shown in FIG. 2 along the horizontal line portion 3c and the vertical line portions 3d and 3e of the planned cleavage groove 3, and the hole diameter and pitch of each hole 4 are as follows. Is as described above.
[0039]
After the holes 4 are formed in the soft resin sheet to be the skin layer 1b as described above, the soft resin sheet is loaded into a predetermined position of a mold (not shown) for injection molding the base material 1a. 1a is injection molded.
[0040]
At this time, the resin injected into the cavity of the mold is molded into a predetermined shape while flowing in the cavity along the back surface of the soft resin sheet. At this time, the holes 4 previously formed in the soft resin sheet are formed. resin flows into a portion of the inner.
[0041]
However, the resin that has flowed into the hole 4 is prevented from flowing into the hole 4 due to the inflow suppressing action due to the above dimensions of the hole 4, the pressure of the gas that is packed in the hole 4 and stays in the hole 4, and the pressure of the gas emitted from the molten resin. Therefore, the inflow is stopped before the opening 4a as shown in FIG.
[0042]
When the injection molding of the base material 1a is completed as described above, the interior material body 1 that has been molded is taken out from the mold after the base material 1a is cured. The surface of 1a has an integral structure covered with the skin layer 1b, and the portion that does not reach the opening 4a of the hole 4 previously drilled in the skin layer 1b along the planned groove 3 is molded into the base material 1a. because it is closed by a portion of the hard resin, the majority of the holes 4 becomes a solid state by a hard resin, also does not cause problems such as swollen by the resin pressure during molding.
[0043]
As a result, the appearance of the interior material main body 1 is improved, and the resin that has entered the hole 4 prevents the hole 4 from being deformed, so that the appearance shape over time can be stabilized. The resin has a melt flow rate of about 10 to 30 (JIS K-7210), preferably about 15. In the present embodiment, grade HIP145 MFR14.2 made by Grand Polymer Co., which is polypropylene (polypropylene composite, PPC) blended with talc was used.
[0044]
When the molding of the interior material body 1 is completed, the cutting material is cut into the inner surface of the base material 1a using a cutting tool to complete the interior material body 1, and then the inner surface of the interior material body 1 is formed on the inner surface of the base material 1a. The door body 2b provided on the upper surface of the case 2a of the airbag device 2 is attached, and the inner surface of the base material 1a and the door body 2b are joined together with the inner surface of the base material 1a being in close contact with the inner surface of the door body 2b. This is performed by vibration welding in which vibration is applied to the two, and of course, the two may be joined by other methods such as adhesion.
[0045]
Next, the action when the automobile using the interior material constructed as described above collides and the airbag device 2 is activated will be briefly described.
[0046]
When the inertia generated when the automobile collides is detected, the inflator generates high-pressure gas and inflates the airbag.
[0047]
When the airbag starts inflating, the door body 2b of the case 2a is pushed open around the hinge portion 2c by the inflation pressure, so that the horizontal line portion 3c in the planned tearing groove 3 of the interior material body 1 covering the airbag device 2 And the vertical line portions 3d and 3e are substantially H-shaped, which causes the skin layer 1b to be ruptured from the hole 4 drilled along the groove 3 to be cleaved. Therefore, a material that does not easily break is used for the skin layer 1b. Even in this case, the skin layer 1b can be reliably broken into a predetermined shape.
[0048]
In the above-described embodiment, the case where the groove 3 to be cleaved is formed on the inner surface of the base material 1a of the interior material main body 1 in a substantially letter shape, but the door body 2b provided on the upper surface of the case 2a is opened in one side. In the case of the airbag device 2, the cleavage intended groove 3 formed on the inner surface of the base material 1 a is cut into a substantially square shape.
[0049]
Further, the hole 4 drilled in the skin layer 1b along the planned groove 3 is drilled in a substantially U shape along the three sides excluding the hinge portion 2c of the door body 2b, as in the modification shown in FIG. Therefore, the thickness of the soft resin sheet used for the skin layer 1b and the hole diameter and pitch of the holes 4 drilled in the skin layer 1b are the same as those in the above embodiment.
[0050]
On the other hand, FIG. 7 shows a modification in the case where the hole 4 drilled in the skin layer 1b is a blind hole 4b. When the hole 4 is drilled from the back side of the soft resin sheet forming the skin layer 1b, FIG. A method of forming the blind hole 4b by drilling so that the hole 4 does not reach the surface side of the soft resin sheet, and injecting the base material 1a by loading the soft resin sheet having the above-described configuration into the mold. Since this is the same as in the above embodiment, the description thereof will be omitted. In this case as well, a part of the resin forming the substrate 1a flows into the blind hole 4b, and in this modification, the resin flowing into the blind hole 4b It does not appear on the surface of the skin layer 1b. The small-diameter blind hole 4b has a large resin flow resistance (hardness to flow), and the flow front of the resin contains the existing air in the blind hole 4b and the gas generated by the molten resin itself. The pressure of the resin is not directly applied to the bottom of the substrate, and the surface of the skin layer (appearance design surface) at the location corresponding to the blind hole 4b when the resin is cooled and solidified is not raised.
[0051]
In each of the above-described embodiments and modifications, the groove 3 to be cut is cut on the inner surface of the base material 1a of the interior material body 1 that has been molded. However, when the base material 1a is injection-molded, it is scheduled to be cracked. You may make it shape | mold the groove | channel 3 simultaneously. At that time, since the resin flow path at the portion corresponding to the planned cleavage groove 3 is narrowed, the flow rate of the resin is increased and the temperature of the resin is increased by shearing heat generation to increase the fluidity. The flow behavior does not cause problems such as bumps on the surface. In addition, in order to use the above cutting tool, in the aspect in which the base material 1a is injection-molded in advance so as to have the same thickness as the others around the hole 4, the flow of the resin is made almost constant, and the compression shear Since there is no change in the viscosity of the molten resin due to heat generation, the resin flow conditions related to the holes 4 are mild, the range of molding conditions that can be selected is widened, and mass production is easy.
[0052]
【The invention's effect】
The invention as described in detail above, when forming the skin layer covering the surface of the substrate, thereby forming a plurality of holes along the advance cleavage scheduled grooves, the base of a hard resin, one bore Since the hard resin was allowed to flow into the part , the airbag was inflated by the impact when the automobile collided, and when the base material was broken from the planned opening groove, the plurality of holes formed along the planned opening groove Since the skin layer is ruptured, the airbag can be inflated and deployed instantaneously, and even when a material that is difficult to break is used for the skin layer, the skin layer is reliably secured from the plurality of holes formed along the planned tearing groove. Since it can be ruptured, the degree of freedom of the material that can be used for the skin layer is increased, thereby making it possible to easily obtain a high-quality interior material.
[0053]
In addition, since the hole is formed by a through-hole penetrating the front and back surfaces of the skin layer, the resin that has entered a part of the hole closes the opening portion of the hole that appears on the surface of the skin layer. Even if a plurality of holes are formed, the holes appearing on the surface of the skin layer become inconspicuous, which improves the appearance of the interior material and prevents the resin that has penetrated into the holes from deforming the interior material. In addition to stabilizing the appearance shape of the skin over time, if the holes are formed by blind holes where the openings do not appear on the surface of the skin layer, the resin that has entered the pores will appear on the surface of the skin layer Therefore, resins having different colors can be used for the base material and the skin layer.
[0054]
Furthermore, set the skin layer in which a plurality of holes are formed at a position that coincides with the planned cleavage groove formed on the base material at a predetermined position in the mold for molding the base material, and in this state, melt on the back side of the skin layer When molding the base material by injecting the hard resin, the interior material was manufactured by allowing the hard resin to flow into a part of the hole, so that the resin was planned to be cleaved in order to plug the hole formed in the skin layer Even if a plurality of holes are formed along the groove, the holes appearing on the surface of the skin layer become inconspicuous, thereby improving the appearance of the interior material and preventing the resin that has entered the holes from deforming the holes. The appearance shape of the interior material over time can be stabilized.
[0055]
Moreover, after molding the interior material body, if the groove to be cleaved is cut on the inner surface of the base material, there will be no molding defects such as uneven color and sink marks on the surface of the interior material. In addition to being able to reduce the occurrence of defective products, when molding the interior material body, if the groove to be split is formed integrally with the inner surface of the base material, the groove to be split is formed when the base material is molded. Therefore, the number of man-hours can be reduced as compared with the case where the groove to be cleaved is cut by post-processing.
[Brief description of the drawings]
FIG. 1 is a partially cutaway perspective view of an automotive interior material according to an embodiment of the present invention in use.
FIG. 2 is a plan view of an automobile interior material according to an embodiment of the present invention.
FIG. 3 is a plan view of a cleavage-scheduled groove formed on the inner surface of the automotive interior material according to the embodiment of the present invention.
4 is a cross-sectional view taken along line AA in FIG.
FIG. 5 is an enlarged view in a circle B in FIG. 4;
FIG. 6 is a plan view showing a modification of a plurality of holes formed in the skin layer of the automobile interior material according to the embodiment of the present invention.
FIG. 7 is an enlarged cross-sectional view showing a modified example of a hole formed in the skin layer of the automobile interior material according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Interior material main body 1a Base material 1b Skin layer 2 Airbag apparatus 3 Scheduled groove 4 Hole 4a Opening part 4b Blind hole

Claims (6)

The interior material body covering the airbag device is composed of a base material formed of a hard resin and a skin layer covering the surface of the base material, and the inner surface of the base material is broken when the airbag is inflated. the vehicle interior material formed cleavage scheduled groove, the skin layer, thereby forming a plurality of holes along said cleavage scheduled grooves, when the substrate is molded by a hard resin, one said bore An interior material for an automobile, wherein the hard resin is allowed to flow into the portion .   The automobile interior material according to claim 1, wherein the hole is formed by a through-hole penetrating the front and back surfaces of the skin layer.   The automotive interior material according to claim 1, wherein the hole is formed by a blind hole in which an opening does not appear on the surface of the skin layer. The interior material body covering the airbag device is composed of a base material formed of a hard resin and a skin layer covering the surface of the base material, and the inner surface of the base material is broken when the airbag is inflated. A method for manufacturing an interior material for automobiles in which a groove to be cleaved is formed, wherein the skin layer in which a plurality of holes are formed at positions corresponding to the groove to be cleaved to be formed in the base material is formed by molding the base material. When the base material is formed by injecting a molten hard resin into a predetermined position in the mold and in this state, the hard resin is caused to flow into a part of the hole. The manufacturing method of the interior material for motor vehicles characterized by these.   The manufacturing method of the interior material for motor vehicles of Claim 4 formed by cutting the said to-be-cleave groove | channel on the inner surface of the said base material after the shaping | molding of the said interior material main body.   The method for manufacturing an automotive interior material according to claim 4, wherein, when the interior material body is molded, the cleavage groove is integrally formed on the inner surface of the base material.

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