JP2014166812A - Airbag door and formation method of skin material for airbag door - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent peripheral scattering of a terminal part of a rupture expected line, by surely rupturing only the rupture expected line to be originally ruptured, in a skin material, in opening operation of an airbag door, without expanding a formation area of the airbag door.SOLUTION: The rupture expected line (39) of the skin material (5) is constituted of a notch (35) formed on the reverse side of the skin material (5) so as not to reach a surface of the skin material (5), and the notch depth of the notch (35) is deeper than the notch depth of the other part (39c) of the rupture expected line (39) in the terminal part of the rupture expected line (39) in the skin material (5), so as to provide a thin part (39d) in which a residual thickness from the surface side of the skin material (5) which is thinner than a place corresponding to the other part (39c) of the rupture expected line (39).

Description

  The present invention relates to an airbag door formed on an instrument panel for a vehicle and a method of forming a skin material used for the airbag door.

  Patent Document 1 discloses an airbag door formed on a vehicle instrument panel having a three-layer structure in which a base material, a foamed resin layer, and a skin material are laminated in this order. This airbag door is a four-way opening type in which a front main door portion, a rear main door portion, and sub-door portions on both sides are divided into four sections by planned break lines.

  The planned fracture line is formed on both the base material and the skin material, and extends to positions corresponding to each other. Specifically, the planned fracture line includes a central fracture planned line that extends linearly in the vehicle width direction, and front and rear side planned fracture lines that extend in a V shape from both ends of the central fracture planned line diagonally outward of the front and rear of the vehicle body. Consists of. In addition, the skin material is formed with hinge portions between the end portions of the left and right side fracture planned lines and between the front and rear side fracture planned lines.

  Thus, the airbag door is demarcated by the instrument panel by the fracture line and the hinge part. And, the airbag door is operated by the airbag device, the center fracture planned line and the side fracture planned line of the base material and the skin material are broken, and both the main door part and both the sub door parts are opened with the hinge part as a fulcrum, The airbag is deployed from the airbag door discharge opening and bulges into the passenger compartment.

  In particular, in Patent Document 1, each side fracture planned line of the skin material extends beyond the hinge portion to the outside of the airbag door, and when the airbag device is activated, each side fracture planned line of the skin material is broken. The air bag door is made to open smoothly and smoothly.

JP 2006-264633 A

  In various types of airbag doors, such as the four-way opening type as described above, and the double door opening type divided into two door parts and the single opening type consisting of one door panel, the airbag door opens from the hinge part as a fulcrum. In the skin material, the periphery of the terminal portion corresponding to the hinge portion of the planned break line is bent when the airbag door is opened. At this time, since a compressive force acts suddenly around the terminal part of the planned break line in the skin material, the breaking force applied to the skin material by the inflation pressure of the airbag is not only the planned break line but also around the terminal part. It extends greatly. Therefore, when the physical properties of the skin material of the airbag door deteriorate due to changes over time, the periphery of the end portion of the planned fracture line in the skin material may be broken and scattered.

  Moreover, in the airbag door of patent document 1, since each side fracture | rupture line of an outer skin material has extended outside the airbag door beyond a hinge part, the formation range of a fracture | rupture schedule line, ie, the formation area of an airbag Is getting wider. Thus, when the formation area of the airbag door is widened, the area in which other vehicle structures can be arranged is narrowed, so that the degree of freedom in designing the instrument panel is lowered.

  The present invention has been made in view of such points, and the object of the present invention is to inherently break the skin material when the airbag door is opened without expanding the formation area of the airbag door. It is to make sure that only the planned break line is broken and to prevent scattering around the terminal portion of the planned break line.

  In order to achieve the above object, in the present invention, the thickness of the end portion of the planned fracture line in the skin material is made thinner than the thickness of the other part of the planned fracture line.

  Specifically, the present invention relates to an airbag door formed on a vehicle instrument panel having a three-layer structure in which a foamed resin layer is formed between a base material and a resin skin material, and the airbag door. The following solution is taken for the method of forming the skin material used.

  That is, the first aspect of the present invention is defined by a planned break line formed at a position corresponding to each other of the base material and the skin material, and a hinge portion that connects ends of the planned break line, and an airbag. It is an airbag door that pivots around a hinge portion and opens when each planned break line breaks when the device is activated. In this airbag door, the planned break line of the skin material is formed by a cut formed on the back side of the skin material so as not to reach the surface of the skin material. That is, the planned fracture line of the skin material is formed at a thin portion corresponding to the cut of the skin material that has become thinner due to the formation of the cut. In the first aspect, the remaining thickness from the front side of the skin material is such that, at the end portion of the planned fracture line in the skin material, the depth of the cut is deeper than the depth of the other part of the planned fracture line. A thin-walled portion having a thickness thinner than other portions of the planned fracture line is provided.

  In this first aspect, since the airbag door pivots and opens with the hinge portion as a fulcrum, the periphery of the terminal portion corresponding to the hinge portion of the planned fracture line in the skin material is bent and suddenly opened when the airbag door is opened. Although it is compressed, a thin portion thinner than the other portion of the planned fracture line is provided at the end portion of the planned fracture line in the skin material. The airbag door can be broken to improve the deployability of the airbag door. That is, the breaking force applied to the skin material due to the inflation pressure of the airbag acts quickly when the thin portion breaks when it reaches the terminal portion from the center side of the planned breaking line, and is released to the outside. It is difficult to reach the periphery of the terminal portion of the planned break line and the extension of the planned break line. As a result, the rupture of the skin material is reliably guided to the end of the skin material according to the planned break line without breaking around the terminal portion of the planned break line and the extension line of the planned break line in the skin material. It is kept in the formation range.

  In the airbag door according to the first aspect, the base line and the skin material are scheduled to be broken in a straight line extending in the vehicle width direction, and a V-shaped diagonally outward side of the vehicle body from both ends of the central broken line. The four sides divided into the main door part on the front side, the main door part on the rear side, and the sub-door parts on the both sides with the planned center break line and the planned side break line. An open-type airbag door may be used. In this four-way opening type airbag door, it is preferable that thin portions are respectively provided at all four locations of the outer terminal portion in the front and rear side fracture planned lines.

  In a four-way opening type airbag door, the side rupture line extends from both ends of the central rupture line in an obliquely outward direction to the front and rear of the vehicle body, so the rupture force applied to the skin material by the inflation pressure of the airbag It is easy to reach the periphery of the planned side rupture line and on the extension line, and the periphery of the outer terminal portion of the front and rear side rupture lines in the skin material is likely to break as compared with the double door type and single door type airbag doors. Even in such a four-way opening type air bag door, if the thin wall portions are provided in all four locations of the outer end portions of the front and rear side planned break lines of the skin material, the outer ends of these front and rear side planned break lines The outer periphery of the part and the extension of each side rupture line are not broken, and the skin material breakage is reliably guided to the outer terminal according to the front and rear side rupture lines, and the central rupture line and subsequent lines. It is kept within the formation range of the front and rear side fracture planned lines.

  In the airbag door according to the first aspect, the thickness around the planned fracture line of the skin material is 1.0 mm or more and 1.4 mm or less, and the remaining thickness of the portion except the thin wall portion of the planned fracture line of the skin material 0.4 mm or more and 0.6 mm or less may be sufficient. According to such a configuration, it is possible to break a relatively thin and light skin material according to a planned break line when the airbag apparatus is operated.

  Furthermore, in the airbag door of the first aspect, when the thickness around the planned rupture line of the skin material and the remaining thickness of the portion other than the thin portion of the planned rupture line of the skin material are set as described above The remaining thickness of the thin portion is preferably 0.2 mm or more and 0.3 mm or less, and the length of the thin portion in the direction along the planned fracture line is preferably 2.0 mm or more and 5.0 mm or less.

  According to such a configuration, it is possible to obscure traces when a thin portion is formed in the terminal portion of the planned fracture line in the skin material, for example, swelling to the front side of the skin material, even if the terminal of the planned fracture line Even if the trace of the thin portion is slightly visible in the portion, the range is relatively short, so that the appearance of the instrument panel is not impaired by providing the thin portion. Therefore, both the developability of the airbag door and the appearance of the instrument panel can be achieved.

  The second aspect of the present invention is that the resin skin material is placed on the mounting table so that the back surface faces upward, and then the cutter is slid relative to the mounting table at a constant height. This is a method for forming a skin material for an airbag door, in which a notch is formed on the back side of the material so as not to reach the surface of the skin material, and a planned fracture line that is broken by the operation of the airbag device is formed. And in the mounting table, in the mounting table, the portion where the terminal portion is to be formed at the planned formation position of the skin material breakage line is placed on the other portion of the skin material at the planned breakage line formation location. The cutter is slid so as to end at the end of the planned break line in a state of being higher than the formed portion, and a cut is formed.

  In the second aspect, in the mounting table, the portion where the terminal portion is placed in the planned formation position of the skin material breakage line is placed on the other portion of the skin material where the planned breakage line formation location is placed. Since the cut is made on the back side of the skin material with the cutter in a state higher than the above-mentioned part, just by sliding the cutter relative to the mounting table at a certain height, at the end of the planned break line, the front side A portion (thin wall portion) in which the remaining thickness from is thinner than other portions of the planned fracture line can be formed. Therefore, the skin material for an airbag door used for the airbag door of the first aspect can be easily formed.

  Furthermore, in the second aspect, since the cutting with the cutter for the back side of the skin material is performed by sliding the cutter so as to end at the end of the planned breaking line, a thin part is formed at the terminal part of the planned breaking line. At that time, it is possible to prevent the traces, for example, swelling of the skin material to the front side, from remaining in a conspicuous state. That is, on the contrary, when forming the cut with the cutter on the back side of the skin material from the end of the planned breaking line, it is strongly pressed to pierce the skin material deeper than the other parts. Therefore, the end portion of the planned fracture line is likely to remain in a conspicuous state when a thin portion is formed on the terminal portion of the planned fracture line, such as by swelling to the front side of the skin material, but according to the second aspect Because the cutter can be sufficiently inserted into the skin material in the sliding process up to the end of the planned break line, the pressing force of the cutter against the skin material when forming the end of the planned break line is excessively strong. It is possible to prevent the traces of the thin-walled portion from remaining in a conspicuous state. Therefore, the appearance of the skin material for the instrument panel, and hence the appearance of the instrument panel, is not impaired by the formation of the planned fracture line, particularly the terminal portion (thin wall portion).

  According to the first aspect of the present invention, the end portion of the skin material on the planned break line can be quickly broken before the periphery breaks, and the airbag door can be formed without expanding the formation area of the airbag door. During the opening operation, only the planned fracture line that should originally be fractured can be reliably broken in the skin material, and scattering around the terminal portion of the planned fracture line can be prevented.

  According to the second aspect of the present invention, it is used for the airbag door according to the first aspect of the present invention without impairing the appearance of the skin material for the instrument panel, and hence the appearance of the instrument panel, by forming the expected fracture line. The skin material for airbag doors can be easily formed.

FIG. 1 is a plan view showing a panel constituent member constituting the left half of an upper panel in an instrument panel according to an embodiment of the present invention. 2 is a cross-sectional view taken along line II-II in FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a process diagram showing a method for forming a skin material for an airbag door according to an embodiment of the present invention. FIG. 5 is a process diagram showing a state when a cut is formed in the skin material for an airbag door according to the embodiment of the present invention. FIG. 6 is a cross-sectional view showing the skin material for an airbag door in which a cut is formed.

  Hereinafter, an airbag door according to an embodiment of the present invention and a method of forming a skin material used therefor will be described in detail based on the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

  In this embodiment, a vehicle instrument panel in which a four-way opening type airbag door is formed as an airbag door according to the present invention will be described as an example.

-Airbag door configuration-
FIG. 1 shows a panel constituting member 1 constituting a left half of an upper panel in a vehicle instrument panel for a right handle. 2 is a cross-sectional view taken along line II-II in FIG. 3 is a cross-sectional view taken along line III-III in FIG. In FIG. 3, only a part near the outer terminal of the planned fracture lines 29 and 39 described later is shown. As shown in FIG. 2, the panel constituent member 1 includes a resin base material 3 that constitutes the back side of the panel constituent member 1 and a resin skin material 5 that constitutes the front side of the panel constituent member 1. It has a three-layer structure in which the foamed resin layer 7 is integrally formed between the base material 3 and the skin material 5.

  The base material 3 is formed by injection molding with a resin material such as polypropylene (PP), polypropylene with fibers, acrylonitrile-butadiene-styrene (ABS) resin, noryl resin, and the like. The skin material 5 is formed by a slush molding, a vacuum molding, or an injection molding with a resin material such as an elastomer resin material made of thermoplastic polyurethane (TPU) or polyvinyl chloride (PVC), for example. The foamed resin layer 7 is a urethane foam or the like, and has a semi-rigid structure in which, for example, independent foaming and continuous foaming are distributed about half each.

  A rear end portion 5b that is spaced apart toward the base material 3 with respect to the main body portion 5a that forms the main body of the outer skin material 5 is formed at the terminal portion of the outer skin material 5 on the vehicle body rear side (occupant side). The front end edge of the rear terminal portion 5b and the rear end edge of the main body portion 5a are integrally connected by a step portion 5c. And the back surface of the rear terminal portion 5b of the skin material 5 is in close contact with the surface of the terminal portion 3a on the vehicle body rear side of the base material 3 to seal between the two.

  Further, the terminal portion 5d excluding the rear terminal portion 5b of the skin material 5 is formed in a state of being folded at an acute angle toward the base material 3 side. On the other hand, a protruding piece 3b having a substantially triangular cross section is provided at a position corresponding to the folded portion 5d of the skin material 5 in the base material 3. The inner surface of the protruding piece 3b faces the outer surface of the folded portion 5d of the skin material 5. And the outer surface of the folding | returning part 5d in the skin material 5 closely_contact | adheres to the inner surface of the protrusion 3b in the base material 3, and seals between both.

  An airbag chute portion 11 is integrally provided on the back side of the portion of the base material 3 closer to the front of the vehicle body. The airbag chute 11 includes a rectangular cylindrical frame 15 in which an airbag device 13 including an airbag and an inflator for protecting a passenger in a passenger seat from an impact in the longitudinal direction of the vehicle body is accommodated. I have. The frame 15 includes a front frame wall 15a extending in the vehicle width direction, a rear frame wall 15b disposed opposite to the rear side of the front frame wall 15a and extending in the vehicle width direction, and extending in the vehicle body longitudinal direction. The left frame wall (not shown) that connects the left edges of the front frame wall 15a and the rear frame wall 15b and the right edges of the front frame wall 15a and the rear frame wall 15b that extend in the longitudinal direction of the vehicle body And a right frame wall (not shown).

  A plurality of retaining holes 17 (one each appearing in FIG. 2) are formed in the front frame wall 15a and the rear frame wall 15b at intervals in the vehicle width direction. A plurality of hooks 19 (one each appearing in FIG. 2) attached to the airbag device 13 are inserted into these latching holes 17, and the hooks 19 are connected to the latching holes 17 when the airbag device 13 is operated. Only the airbag door 25, which will be described later, is hooked on the periphery and is pressed upward by the airbag. The airbag device 13 is fixed by a bracket 21 to an instrument panel reinforcement (not shown) that is bridged to a side panel of the vehicle body.

  On the inner side of the upper end portion of the frame body 15 in the airbag chute portion 11, a backup flap portion 23 is integrally formed so as to close the upper end side inside the frame body 15. In the panel component 1, a four-way opening type airbag door 25 is formed in a rectangular shape in a three-layer structure region corresponding to the flap portion 23. That is, the airbag door 25 shares the skin material 5 and the foamed resin layer 7 with the panel constituent member 1 around the airbag door 25. Further, the flap portion 23 serves as the base material 3 of the airbag door 25 and also serves as the base material 3 of the panel constituent member 1.

  On the back side of the flap portion 23, a mountain-shaped V groove 27 extending in a shape in which reverse arrows are added to both ends of a straight line extending in the vehicle width direction is formed so as not to reach the surface of the substrate 3. Specifically, as shown in FIG. 1, the V groove 27 is formed at the center of the back surface of the flap portion 23 and extends linearly in the vehicle width direction, and from both ends of the first groove 27a. It consists of front and rear second grooves 27b extending in a V shape on the front and rear sides of the vehicle body.

  The flap portion 23 is formed with a base material breakage planned line 29 that is broken by the operation of the airbag device 13 by a thin portion corresponding to the V groove 27. As shown in FIG. 1, the base material planned break line 29 corresponds to the central fracture planned line 29 a formed by a thin portion corresponding to the first groove 27 a and extending linearly in the vehicle width direction, and the second groove 27 b. The front and rear side planned break lines 29b are formed by thin-walled portions extending from the both ends of the central planned break line 29a to the front and rear sides of the vehicle body in a V shape.

  Further, the front and rear horizontal hinge portions 31 and the vertical hinge portions 33 on both sides are formed to be thinned with a predetermined width at the boundary between the flap portion 23 and the frame body 15 (see FIGS. 1 to 3). The front and rear horizontal hinge portions 31 connect the outer terminals of the side fracture planned lines 29b adjacent to each other in the vehicle width direction of the base material 3. On the other hand, the vertical hinge portions 33 on both sides connect the outer terminals of the front and rear side fracture planned lines 29 b in the base material 3.

  Further, on the back side of the portion corresponding to the flap portion 23 in the skin material 5, a shape similar to the V groove 27 formed in the base material 3, that is, a shape in which reverse arrows are added to both ends of a straight line extending in the vehicle width direction. Is formed so as not to reach the surface of the skin material 5. This cut 35 is formed at the center of the portion corresponding to the flap portion 23 in the skin material 5 and extends linearly in the vehicle width direction, and the V cut diagonally outward from the both ends of the vehicle body from both ends of the first cut 35a. It consists of front and rear second cuts 35b extending in a letter shape. The cut 35 of the skin material 5 and the V groove 27 of the flap portion 23 overlap each other vertically with the foamed resin layer 7 interposed therebetween. That is, the first groove 27a and the first cut 35a, and the second groove 27b and the second cut 35b are formed at positions corresponding to each other in the skin material 5 and the flap part 23, respectively.

  As shown in FIGS. 2 and 3, an adhesion preventing agent 37 is interposed in the cut 35 of the skin material 5. This adhesion inhibitor 37 is in a liquid form, and when dried, moisture evaporates and the components remain in a film form. One example is a surfactant. The anti-adhesive agent 37 is not limited to this, and may be an aqueous solution of silicon dioxide or the like. In short, any component may be used as long as the melting temperature of the components is higher than that of the skin material 5 and moisture easily evaporates. In the present embodiment, since the adhesion preventing agent 37 is interposed in the cut 35 of the skin material 5 in this way, even if the side walls in the cut 35 are softened and melted in a high temperature environment, Adhesion is prevented by an anti-adhesive agent 37 in the cut 35 so that the cut 35 is not blocked.

  In the skin material 5, a skin material planned break line 39 that is broken by the operation of the airbag device 13 is formed by a thin portion corresponding to the cut 35. This skin material planned break line 39 is formed by a thin center portion 39a formed by a thin portion corresponding to the first cut 35a and extending linearly in the vehicle width direction, and a thin portion corresponding to the second cut 35b. It consists of front and rear side planned fracture lines 39b extending in a V-shape from both ends of the central fracture planned line 39a diagonally outward in the longitudinal direction of the vehicle body. The skin material planned break line 39 and the base material planned break line 29 overlap each other vertically with the foamed resin layer 7 interposed therebetween. That is, the center portion planned break line 29a of the base material 3 and the center portion break planned line 39a of the skin material 5, and each side portion break planned line 29b of the base material 3 and each side portion break planned line 39b of the skin member 5 are the flap portion 23. And the skin material 5 are formed at positions corresponding to each other.

  The airbag door 25 is demarcated in the panel component 1 by the above-described base material planned break line 29 and skin material planned break line 39, the horizontal hinge part 31, and the vertical hinge part 33, and is configured as a four-way opening type. Specifically, the airbag door 25 is surrounded by the horizontal hinge part 31 and the vertical hinge part 33 on all sides, and the center fracture planned lines 29a and 39a of the base material 3 and the skin material 5 and the respective side fracture planned lines 29b, 39b, the front main door portion 25a, the rear main door portion 25b, and the sub door portions 25c and 25d on both sides are divided into four sections. In addition, the airbag door 25 is configured as a so-called seamless type in which the skin material planned break line 39 cannot be identified from the surface side of the panel component 1 when the airbag apparatus 13 is not in operation.

  In the panel component 1 having the airbag door 25 having the above-described configuration, the airbag of the airbag device 13 is inflated by the operation of the inflator at the time of a vehicle collision, and the airbag is pressed upward by the inflation pressure. The base material planned break line 29 and the skin material planned break line 39 are broken, respectively, and the front main door portion 25a, the rear main door portion 25b, and the sub door portions 25c and 25d on both sides both support the hinge portions 31 and 33. Rotate upwards in the vehicle longitudinal direction and open in all directions. At this time, since the periphery of the outer terminal portion of each side fracture planned line 39b in the skin material 5 corresponds to the hinge portions 31 and 33, it will be bent and rapidly compressed, so if any measures are not taken The rupture force applied to the skin material 5 due to the bulging pressure of the airbag is large not only in the skin material rupture line 39 but also around the outer terminal portion of each side rupture line 39b. The skin material 5 may be broken and scattered around the outer terminal portion 39b.

  Therefore, in the present embodiment, the portions 39d thinner than the other portions 39c of the skin material planned break line 39 are provided at all four locations of the outer end portion of each side fracture planned line 39b of the skin material 5. That is, the skin material planned break line 39 includes the first thin portion 39c constituting substantially the entire skin material planned break line 39 except for the outer terminal portion of each side planned break line 39b, and each side planned fracture line 39b. It has the 2nd thin part 39d which comprises an outer side terminal part thinner than the 1st thin part 39c. The remaining thickness from the front side of the skin material 5 in the second thin portion 39d is such that the cut depth of the cut 35b at the location corresponding to the second thin portion 39d is greater than the cut depth at the location corresponding to the first thin portion 39c. By being deep, it is thinner than the remaining thickness from the front side of the skin material 5 in the first thin portion 39c. This second thin portion 39d is the thin portion of the present invention. Thereby, even if the periphery of the outer terminal portion of each side fracture planned line 39b in the skin material 5 is suddenly compressed during the operation of the airbag device 13, the second thin wall constituting the outer terminal portion of each side fracture planned line 39b The portion 39d can be quickly broken before its periphery breaks, and the deployability of the airbag door 25 can be improved.

  That is, the second thin portion 39d constituting the outer terminal portion of each side fracture planned line 39b among the planned skin material breakage lines 39 is thinner than the first thin portion 39c constituting the other portion of the planned skin material breakage line 39. Thus, when the breaking force applied to the skin material 5 due to the inflation pressure of the airbag reaches the end portion of each side fracture planned line 39b from the central fracture planned line 39a, the second thin portion 39d breaks. It acts quickly and is released to the outside, and it is difficult to reach the periphery of the outer terminal portion of each side fracture planned line 39b and the extension line of each side fracture planned line 39b. Therefore, the skin material 5 breaks along each side fracture planned line 39b without breaking around the outer terminal portion of each side fracture planned line 39b in the skin material 5 and on the extension line of each side fracture planned line 39b. While being surely guided to the outer terminal, it is kept within the formation range of the center fracture planned line 39a and each subsequent side fracture planned line 39b.

  The thickness of the skin material 5 around the planned skin material breaking line 39 is, for example, 1.0 mm or more and 1.4 mm or less. The skin material 5 is substantially the same thickness in substantially the entire skin material 5 excluding the formation portion of the skin material planned break line 39, and is relatively thin and lightweight. In addition, the remaining thickness from the front side of the skin material 5 in the first thin portion 39c of the planned skin material breaking line 39 should be preferentially broken when the airbag device 13 is operated. For example, it is set to 0.4 mm or more and 0.6 mm or less. Further, a transition portion 39e that gradually becomes thinner from the first thin portion 39c toward the second thin portion 39d is formed between the first thin portion 39c and the second thin portion 39d.

  The remaining thickness from the front side of the skin material 5 in the second thin portion 39d is made inconspicuous, for example, traces when the second thin portion 39d is formed, for example, swelling of the skin material 5 to the front side, as will be described later. For example, it is set to 0.2 mm or more and 0.3 mm or less. Further, the length of the second thin portion 39d in the direction along the planned side rupture line 39b of the skin material 5 is relatively short even if the trace of the second thin portion 39d is slightly visible, In order to make it difficult for the skin material 5 to tear even if the occupant carelessly presses the airbag door forming portion of the panel component 1 or its peripheral portion, it is set to, for example, 2.0 mm or more and 5.0 mm or less. Thus, by setting the remaining thickness and length of the second thin portion 39d, it is possible to achieve both the deployability of the airbag door 25 and the appearance of the panel component 1 described above.

-Method for forming skin material-
Next, an example of the method for forming the skin material 5 for the airbag door 25, that is, the skin material 5 of the panel constituent member 1 provided with the airbag door 25 will be described with reference to FIGS. 1 and 4 to 6. I will give you a description. FIG. 4 is a process diagram showing a method for forming the skin material 5. FIG. 5 is a process diagram showing how the cuts 35 are formed in the skin material 5. FIG. 6 is a cross-sectional view showing the skin material 5 in a state where the cuts 35 are formed.

  First, as shown in FIG. 4A, the skin material 5 made of, for example, TPU formed into a predetermined shape by slush molding, vacuum molding, or injection molding is mounted on the mounting table 41 so that the back surface thereof faces upward. . Next, the skin material 5 is adsorbed to the mounting table 41 by vacuum suction means (not shown) provided on the mounting table 41. The mounting table 41 is formed with a through hole 41a having a shape in which reverse arrows are added to both ends of a straight line extending in the vehicle width direction so as to correspond to the shape of the notch 35 to be formed. A push-up jig 43 having a tip formed in a convex curved surface and having the same shape as the through-hole 41a is disposed in the through-hole 41a so as to be able to move in and out in the vertical direction. The lifting jig 43 constitutes a part of the mounting table 41.

  In the push-up jig 43, a portion 43a where the end portion of the skin material 5 on which the skin material planned break line 39 is to be formed is slightly raised above the other portion 43b. 5 is higher than the portion 43b on which another portion of the planned skin material breakage line 39 is to be formed (shown in FIG. 5 to be referred to later). In the stage of FIG. 4A, the lifting jig 43 is immersed downward from the mounting table 41, and its tip is positioned at substantially the same level as the upper surface of the mounting table 41, and the skin material in the skin material 5 is scheduled to break. The portion where the line 39 is to be formed runs along the upper surface of the mounting table 41 in a flat state without being uneven.

  Subsequently, as shown in FIG. 4 (b), the lifting jig 43 is protruded upward from the mounting table 41, and the planned formation point of the skin material breaking line 39 in the skin material 5 is pushed from the surface side (downward). Push up with the lifting jig 43.

  Next, as shown in FIG. 4C, the cold cutter 45 disposed above the planned formation position of the skin material breaking line 39 on the back side of the skin material 5 is lowered in the pushed-up state of FIG. 4B. As shown in FIG. 5, the skin is slid relative to the mounting table 41 at a certain height while the cutting edge is inserted into the planned formation place of the skin material breaking line 39, thereby A cut 35 is formed on the back side of the material 5 so as not to reach the surface of the skin material 5. At this time, the notch 35 is formed, and at the same time, the notch 35 is opened in a V shape by the stress caused by the lifting of the lifting jig 35. The “cold cutter 45” referred to here is a cutter that is not heated or vibrated, and means that it excludes a hot blade or an ultrasonic cutter that melts heat with a resin to make a cut. The cut 35 is formed on the back side of the skin material 5 by sliding the cold cutter 45 so as to end at the end of each side fracture planned line 39b.

  Exemplifying a specific procedure for forming the notch 35, first, the cold cutter 45 is formed into the center fracture planned line 39a while being inserted into the skin material 5 from a position closer to the left end of the planned planned section break line 39a. It slides to the right end along the planned location, and further changes the direction of the blade of the cold cutter 45 from there, and extends along the planned location of the first side fracture planned line 39b extending diagonally outward and rearward to the right side of the vehicle body. Are continuously slid to form a cut 35 at the slide location (path A shown in FIG. 1). Then, the cold cutter 45 is pulled out from the skin material 5 when the cut 35 is formed up to the outer terminal at the planned formation position of the first side fracture planned line 39b.

  Next, the cold cutter 45 is slid to the right end along the planned formation position of the central fracture line 39a while being inserted into the skin material 5 from the position near the right edge among the planned formation areas of the central fracture line 39a. Further, by changing the direction of the blade of the cold cutter 45 from there, the slide part is continuously slid to the outer terminal along the planned part of the second side fracture planned line 39b extending diagonally outward and forward right of the vehicle body. A notch 35 is formed in (path B shown in FIG. 1). Then, the cold cutter 45 is pulled out from the skin material 5 when the cut 35 is formed up to the outer end at the planned formation location of the second planned side break line 39b.

  Subsequently, the cold cutter 45 is slid from the position closer to the right end of the planned center fracture line 39a than the first slide start point to the left end along the planned center fracture line 39a. Further, the direction of the cold cutter 45 is changed from there, and it is continuously slid to the outer terminal along the planned formation side of the third side fracture planned line 39b extending obliquely outwardly to the left front of the vehicle body, so that the cut is made at the slide location. 35 is formed (path C shown in FIG. 1). Then, the cold cutter 45 is pulled out from the skin material 5 when the cut 35 is formed up to the outer terminal at the planned formation location of the third side fracture planned line 39b.

  Finally, the cold cutter 45 is slid from the same location as the third slide start point to the left end along the planned formation point of the central fracture line 39a, and the blade direction of the cold cutter 45 is changed from there. By continuously sliding to the outer terminal along the planned formation location of the fourth side fracture planned line 39b extending diagonally outward rear left of the vehicle body, a cut 35 is formed at the slide location (path D shown in FIG. 1). . Then, the cold cutter 45 is pulled out from the skin material 5 when the cut 35 is formed up to the outer terminal at the planned formation location of the fourth side fracture planned line 39b.

  Through the above procedure, the cut 35 can be formed on the back side of the skin material 5. In addition, by forming the cut 35 on the back side of the skin material 5 in this way, a skin material planned break line 39 that is broken by the operation of the airbag device 13 is formed by a thin portion corresponding to the cut 35.

  According to such a method of forming the planned skin material breakage line 39, as shown in FIG. 5, in the push-up jig 43, the end portion of the skin material 5 at the planned skin material breakage line 39 is placed. Since the portion 43a is higher than the portion 43b on which the other portion of the skin material planned break line 39 of the skin material 5 is to be formed, the cold cutter 45 is placed at a constant height on the mounting table 41. 6, as shown in FIG. 6, as shown in FIG. 6, the remaining thickness from the front side is the other part of the skin material planned break line 39, that is, the first thin part 39 c. A thinner second thin portion 39d is formed. Moreover, since the cut 35 is formed by the cold cutter 45, the side walls in the cut 35 can be formed to be extremely close to each other, and the mark of the cut 35 does not appear on the surface of the skin material 5 due to the heat effect. The appearance of the skin material 5 is not impaired.

  By the way, when the formation of the notch 35 with the cold cutter 45 on the back side of the skin material 5 is started from the outer end of the side break planned line 39b, the cold cutter 45 is inserted deeper into the skin material 5 than the other portions. Since it will be strongly pressed, the outer terminal portion of the planned side rupture line 39b swells to the front side of the skin material 5, and the trace when the second thin portion 39d is formed on the outer terminal portion of the planned side rupture line 39b. Is likely to remain in a conspicuous state.

  On the other hand, in the present embodiment, the cold cutter 45 is slid so as to end at the outer end of each side break planned line 39b to form the cut 35, so that it reaches the outer end portion of each side break planned line 39b. The cold cutter 45 can be sufficiently inserted into the skin material 5 during the sliding process. Thereby, it is not necessary to excessively increase the pressing force of the cold cutter 45 against the skin material 5 when forming the terminal portion of each side break planned line 39b, that is, the second thin portion 39d. It is possible to prevent the trace when the second thin-walled portion 39d is formed in the outer terminal portion from remaining in a conspicuous state. Therefore, the appearance of the skin material 5 and thus the appearance of the panel component 1 are not impaired by the formation of the outer skin portion planned line 39, particularly the outer terminal portion (second thin portion 39d) of each side fracture planned line 39b.

  After the cut 35 is formed as described above, the tip of the nozzle 47 is made to correspond to the V-shaped cut 35 as shown in FIG. 37 (surfactant or silicon dioxide aqueous solution) is injected. In this way, since the liquid adhesion inhibitor 37 is injected into the V-shaped cut 35, the injection of the adhesion inhibitor 37 is easy, and the adhesion inhibitor can be reliably interposed in the cut 35. . At this time, the adhesion preventing agent 37 may be applied to the cuts 35 by using a brush instead of the injection by the nozzle 47.

  Contrary to the above, first, the incision 35 is first formed by the cold cutter 45 at the planned breaking line 39 on the back side of the skin material 5 so as not to reach the surface of the skin material 5. Is formed by the operation of the airbag device 13, and then the push-up jig 43 is protruded upward from the mounting table 41 so that the skin material planned break line 39 is formed on the surface side. It is also possible to open the notch 35 in a V shape by pushing it up with a lifting jig 35 and to inject or apply a liquid adhesion inhibitor 37 to the notch 35.

  Next, as shown in FIG. 4 (e), the lifting jig 43 is immersed downward from the mounting table 41, and its tip is positioned at the same level as the upper surface of the mounting table 41. Thereby, the cut line 35 opened in the V shape closes along the upper surface of the mounting table 41 in a flat state without the uneven surface line 39 of the skin material being uneven. Along with this, an excessive adhesion preventing agent 37 in the cut 35 protrudes to the periphery. This protruding adhesive agent 37 is wiped off as shown in FIG. 4 (f) so as not to impede the adhesion with the foamed resin layer 7 when the airbag door 25 (panel component 1) is molded. In this way, when the notch 35 that has been opened in the V shape is closed, the excess anti-adhesive agent 37 can be easily discharged from the notch 35, so that the inside of the notch 35 is compared with the case where a powdery anti-adhesive agent is used. The adhesion preventing agent 37 does not remain excessively, and the excessively remaining adhesion preventing agent 37 does not impair the appearance of the cuts 35 on the surface of the skin material 5.

  After that, although not shown, the skin material 5 is carried into the heating and drying furnace from the mounting table 41, set on a setting jig with the surface facing upward, and the adhesion preventing agent 37 in the cut 35 is dried to dry the moisture. And the components remain in the cut 35 in the form of a film. In this way, unnecessary moisture can be easily removed from the cut 35 by simply drying the adhesion inhibitor 37. In the drying process, when the airbag door 25 (panel component 1) is molded, the skin material 5 is softened to fit the molding surface of the forming mold, and is along the surface of the set jig corresponding to the product shape. This can be done using a shaping process. In addition, this drying process may be a separate process from the shaping process.

  Through the above steps, the skin material 5 for the airbag door 25 according to the present embodiment can be formed.

-Effect of the embodiment-
According to the airbag door 25 of this embodiment, the terminal portion of each side break planned line 39b of the skin material 5 can be quickly broken before the periphery breaks, and the formation area of the airbag door 25 is widened. In the opening operation of the air bag door 25, the skin material 5 is surely broken only in the skin material planned break line 39 that should originally be broken, so that the side break planned lines 39b are prevented from scattering around the terminal portion. Can do.

  In addition, according to the method for forming the skin material 5 of this embodiment, the formation of the skin material expected break line 39 does not impair the appearance of the skin material 5 and thus the appearance of the panel constituent member 1 constituting the instrument panel. The skin material 5 for the airbag door 25 can be easily formed.

  In the above-described embodiment, a liquid material is used as the adhesion preventing agent 37. However, the adhesion preventing agent 37 may be a powdered material such as lime or silicon dioxide. Moreover, the adhesion preventing agent 37 may not necessarily be provided.

  Moreover, in the said embodiment, although the air bag chute | shoot part 11 was integrated with the base material 3 of the panel structural member 1, these airbag chute parts 11 and the base material 3 of the panel structural member 1 are separate bodies. There may be.

  In the above embodiment, the method of forming the cut 35 constituting the skin material planned break line 39 by using a cold cutter has been described. However, the present invention is not limited to this, and the cut 35 is formed at the time of formation. If the material 5 is not softened and melted, it may be formed using other notch forming means such as an ultrasonic cutter or a laser.

  In addition, in the above-described embodiment, a four-way opening type airbag door partitioned into four door portions has been described as an example. However, the present invention is not limited thereto, and a double door opening type partitioning into two door portions or Needless to say, the present invention can also be applied to a single-opening type airbag door composed of one door panel, and the remaining thickness from the front side of the skin material at the end portion of the skin material breaking planned line 39 is the planned breaking line 39. It is only necessary to provide the second thin portion 39d thinner than the first thin portion 39c constituting the other portion.

  As described above, the present invention is useful for an airbag door and a method for molding an airbag door skin material, and in particular, when the airbag door is opened without expanding the formation area of the airbag door, In a method for forming an air bag door and a cover material for an air bag door that is desired to reliably break only a line to be broken, which should originally be broken, and prevent scattering around the terminal portion of the line to be broken. Is suitable.

1 Panel component (vehicle instrument panel)
DESCRIPTION OF SYMBOLS 3 Base material 5 Skin material 7 Foamed resin layer 13 Airbag apparatus 25 Airbag door 25a Front side main door part 25b Rear side main door part 25c, 25d Sub door part of both sides 29 Base material expected breaking line 29a Center of base material Planned fracture line 29b Planned side fracture line of base material 35 Cut 39 Surface skin material planned fracture line 39a Surface material center fracture planned line 39b Surface material again planned fracture line 39c First thin part 39d Second thin part 41 Mounting table 45 Cold cutter

Claims (4)

In a vehicle instrument panel (1) having a three-layer structure in which a foamed resin layer (7) is formed between a base material (3) and a resin skin material (5), the base material (3) and the skin Demarcated by planned break lines (29, 39) formed at positions corresponding to each other of the material (5) and hinge portions (31, 33) connecting the ends of the respective planned break lines (29, 39) When the airbag device (13) is actuated, each of the planned break lines (29, 39) is broken, so that the hinge doors (31, 33) are pivoted around the fulcrum to open. And
The expected fracture line (39) of the skin material (5) is constituted by a cut (35) formed on the back side of the skin material (3) so as not to reach the surface of the skin material (3).
In the end portion of the planned fracture line (39) in the skin material (5), the depth of cut of the cut (35) is deeper than the depth of cut of the other part (39c) of the planned fracture line (39). Thus, an air characterized in that a thin-walled portion (39d) in which the remaining thickness from the front side of the skin material (5) is thinner than the other portion (39c) of the planned fracture line (39) is provided. Bag door. In the airbag door according to claim 1,
Each of the planned break lines (29, 39) includes a central planned break line (29a, 39a) extending linearly in the vehicle width direction and a diagonally V-shaped front and rear of the vehicle body from both ends of the central planned break line (29a, 39a). It consists of the front and rear side break planned lines (29b, 39b) extending in a letter shape,
A front main door portion (25a), a rear main door portion (25b), and sub-door portions on both sides (25c, 39b) and the side break planned lines (29b, 39b). 25d) is a four-way opening type divided into four sections,
The airbag door characterized in that the thin-walled portion (39d) is provided at all four locations of the outer end portion of the front and rear side break planned lines (39b). In the air bag door according to claim 1 or 2,
The thickness around the expected fracture line (39) of the skin material (5) is 1.0 mm or more and 1.4 mm or less,
The remaining thickness of the thin part (39d) of the skin material (5) is not less than 0.2 mm and not more than 0.3 mm, and the length of the thin part (39d) in the direction along the planned fracture line (39) Is 2.0 mm or more and 5.0 mm or less,
An airbag having a remaining thickness of a portion (39c) excluding the thin-walled portion (39d) of the planned breaking line (39) of the skin material (5) is 0.4 mm or more and 0.6 mm or less door. After placing the resin skin material (5) on the mounting table (41) with the back side facing upward, slide the cutter (45) at a fixed height relative to the mounting table (41). A cut (35) is formed on the back side of the skin material (5) so as not to reach the surface of the skin material (5), and a break line (39) that is broken by the operation of the airbag device (13) is formed. A method for forming a skin material for an airbag door to be formed,
In the mounting table (41), the portion (43a) on which the end portion of the planned breakage line (39) of the skin material (5) is placed is replaced with the planned breakage line of the skin material (5) ( 39) In the state where the other part of the planned formation part of 39) is made higher than the part (43b) on which the part is placed, the cutter (45) is slid so as to end at the end of the planned fracture line (39) and the cut (35) A method for forming a skin material for an air bag door, characterized by forming.