JP2007145234A - Shock absorbing body for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance productivity by eliminating molding failure such as generation of short shot and burr at molding of a shock absorbing body for a vehicle in the shock absorbing body for the vehicle comprising a lattice-like rib made of resin arranged on a back surface of an interior trim. <P>SOLUTION: A roof side bracket (shock absorbing body for a vehicle) 30 installed at an inner surface of a roof trim 10 comprises the lattice-like rib made of resin, and is constituted by arranging a peripheral rib 31 comprising a side wall rib 32 and a terminal end wall rib 33, and a vertical rib 34 and a lateral rib 35 inside the peripheral rib 31 in a lattice-like shape. Further, a ceiling plate 36 is formed on at least any one of the vertical rib 34 or the side wall rib 32 along a longitudinal direction, flowability of the resin is enhanced by using the ceiling plate 36 as a resin passage to avoid the short shot, generating no burr, the number of gates 43 can be also reduced and facility of a metal die can be also simplified. Further, since a pressing pin 46 can be set to an optional position utilizing the ceiling plate 36, shape-forming freedom can be enhanced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a shock absorber for a vehicle composed of resin-made grid-like ribs, and in particular, by devising the shape, it is possible to improve the resin flow during molding, and it can be manufactured with excellent productivity and low cost. The present invention relates to a shock absorber for a vehicle.

  Normally, various shock absorbers are provided in the vehicle, and the load applied to the occupant is reduced by the deformation or crushing of the shock absorber with respect to an external impact load. For example, as this vehicle impact absorber, a resin molded body based on a resin-made grid-like rib or a resin foam molded body such as foamed beads or urethane foam is generally known.

  Here, a conventional example of resin-made grid-like ribs will be described with reference to FIG. As shown in the drawing, a roof trim 2 as an interior material is mounted on the indoor surface side of the roof panel 1, and in particular, a curtain-type airbag 3 is provided on the side portion in order to protect passengers on the indoor side. Etc., and a roof side bracket 4 made of resin-made lattice ribs as shown in FIG. 12 is attached to the inner surface side of the roof trim 2 as shown in FIG. The roof side bracket 4 effectively absorbs an impact load by deformation or crushing when an impact is applied from the outside.

  The specific configuration of the roof side bracket 4 includes peripheral ribs 4a and 4b each having a periphery composed of side wall ribs 4a extending along the traveling direction of the vehicle and terminal wall ribs 4b of both ends in the longitudinal direction, The ribs 4a and 4b are composed of vertical ribs 4c arranged in a row and horizontal ribs 4d extending in a plurality of rows so as to intersect with the ribs 4a and 4b, and the rib pitches of the various ribs 4a to 4d are set to 25 to 30 mm. The configuration related to the conventional roof side bracket 4 is described in detail in Patent Document 1.

Japanese Patent Laid-Open No. 2001-114033

  Thus, the vehicle shock absorber based on the resin-made grid-like ribs as in the conventional roof side bracket 4 has a grid-like thin rib (thickness of about 1 mm) structure. There is a problem that the resin flow is poor and short shots occur frequently. In addition, when the injection pressure is set high to prevent short shots, burrs are likely to occur due to overfilling. Accordingly, in order to keep the injection pressure low and prevent short shots, it is necessary to set the gate 5 at a large number of locations (for example, 5a to 5f as shown in the figure), which increases the mold cost in the molding die. It has become a major factor.

  Furthermore, since the roof side bracket 4 is a rib surrounded by the four sides constituted by the side wall rib 4a and the terminal wall rib 4b, the roof side bracket 4 bites into the molding die and the releasability is poor. At the time of molding, it is necessary to apply a mold release agent that enhances the mold release property to the mold surface of the molding die, and the process of applying the mold release agent is added. Has been. Further, since the roof side bracket 4 is based on the grid-like ribs, there is only a portion where the extrusion pins are installed at the intersections of the ribs.

  The present invention has been made in view of such circumstances, and is a vehicle impact absorber made of resin-made grid-like ribs typified by the roof side bracket 4, which includes short shots, occurrence of burrs due to overfilling, and the like. It is an object of the present invention to provide an impact absorber for a vehicle that can effectively solve the molding failure, can increase productivity, and can be manufactured at low cost.

  In order to solve the above-described problems, the present invention provides a resin that is interposed between a vehicle body panel and an interior trim so that when an impact is applied to the vehicle, the impact load can be absorbed by deformation or crushing itself. In the vehicle shock absorber composed of a grid-shaped rib made of steel, the vehicle shock absorber has vertical ribs and horizontal ribs arranged in a grid pattern inside peripheral ribs composed of side wall ribs and terminal wall ribs. The top plate having a predetermined width is provided along the edge of at least one of the longitudinal ribs and the side wall ribs that are configured and extend along the longitudinal direction. It is characterized by enhanced sex.

  Here, as an interior trim, in addition to a roof trim, it can be applied to a door trim, a rear side trim, and the like mounted on the interior side of a side wall panel of a vehicle. In addition to the roof side bracket installed on the inner side of the roof trim, the vehicle impact absorber can be applied to a side impact pad attached to the back side of a door trim, a rear side trim, or the like. A shock absorber for a vehicle is composed of a peripheral rib composed of side wall ribs and end wall ribs, and vertical and horizontal ribs arranged inside the peripheral ribs. These various ribs intersect in a substantially orthogonal direction. is doing. The rib pitch is 25 to 30 mm and the tip thickness of the rib is preferably about 1 mm. The injection molding method is optimal as the molding method. Moreover, as a raw material, it can select suitably from PE resin, ABS resin, a polyamide-type resin other than PP resin.

  Next, the thickness of the rib can be set to about 1.2 to 1.3 mm in consideration of the draft angle with respect to the thickness of the tip at 1 mm and the parting surface side. And about each rib which comprises the impact absorber for vehicles, the top plate about 10 mm thick is provided along the edge part of the rib in a vertical rib or a side wall rib. This top plate may be provided over the entire surface. Therefore, when molding a vehicle impact absorber by injecting and filling molten resin into the molding die, the top plate set in the longitudinal direction of the shock absorber becomes a resin passage, and the resin flows from the gate to the top plate. The resin flows smoothly, then branches and the resin quickly flows to the lateral ribs. Therefore, the molten resin spreads throughout the cavity.

  As is apparent from the above configuration, the vehicle shock absorber according to the present invention has a top plate integrally formed along the edge of the longitudinal rib or the side wall rib, based on a resin-made grid-like rib. Therefore, when molding a shock absorber for a vehicle by injecting and filling molten resin into a molding die, the resin flow improves, it is possible to reliably avoid short shots, and there is no need to forcibly increase the injection pressure. Since no burrs are generated due to overfilling and molding defects can be reliably prevented, productivity can be greatly increased. In addition, since the resin flow can be improved, the set number of gates can be reduced, so that the processing of the molding die can be simplified.

  Next, in a preferred embodiment of the present invention, the vehicle impact absorber is molded into a required shape by injecting and filling molten resin into a cavity of a molding die, and then the top plate is pushed by an extrusion pin. It is characterized in that the mold releasability from the molding die is improved by extruding in the die-cutting direction. And according to this embodiment, since it is only necessary to set the push pin so as to contact the lower surface of the top plate, by the action of this push pin, the vehicle impact absorber can be pushed up in the die-cutting direction, While improving the mold release property of a molded article, the freedom degree of the setting position of an extrusion pin can be raised.

  As described above, the vehicle impact absorber according to the present invention is based on resin-made grid-like ribs, and vertical ribs and horizontal ribs are arranged in a grid form inside the peripheral ribs. A top plate is set along the edge of the rib or side wall rib, and by pouring resin through this top plate, molding defects such as conventional short shot and overfilling can be reliably avoided, and molding defects are drastically reduced. Can be solved. Furthermore, since the number of gate setting points can be reduced and the machining cost of the mold can be reduced, the productivity can be improved and the mold cost can be reduced.

  Furthermore, according to the embodiment of the present invention, if a configuration is adopted in which the top plate is integrated with the grid-like ribs, and the extruding pin is applied to the top plate to enhance the demolding property, the releasability is improved. As a result, the productivity can be further improved and the degree of freedom of processing in the molding die can be improved, for example, the setting location of the extrusion pin can be freely set.

  Hereinafter, as an embodiment of a vehicle shock absorber according to the present invention, an embodiment applied to a roof side bracket installed on the back side of a roof trim will be described. Note that the gist of the present invention is as described in the scope of claims, and the contents of the embodiments described below are merely examples of the present invention.

  1 to 10 show an embodiment of the present invention. FIG. 1 is an explanatory view showing a roof trim and a roof side bracket. FIG. 2 is a sectional view showing a state in which the roof trim and the roof side bracket are attached to a vehicle. 3 is a perspective view showing a roof side bracket which is an example of a vehicle shock absorber according to the present invention, FIG. 4 is a cross-sectional view showing the structure of the roof side bracket shown in FIG. 3, and FIG. FIG. 6 is an explanatory diagram showing a resin flow during molding of the roof side bracket, FIG. 7 is an explanatory diagram showing a state during demolding after molding the roof side bracket, and FIGS. FIG. 10 shows a modification of the present invention, FIG. 8 is a perspective view showing a modification in which the installation position of the top plate in the roof side bracket is changed, and FIG. 9 is a roof side bracket of FIG. Explanatory view showing a 2-cavity state, and FIG. 10 is a perspective view showing a modified example in which a top plate on one side entire surface.

  1 and 2, a roof trim 10 is applied as an interior trim to which a vehicle shock absorber according to the present invention is attached. The roof trim 10 maintains the rigidity of attachment to the roof panel 20 and the product shape. The surface of the base material 11 is made by sticking a skin 12 for maintaining good decoration and touch, and is attached to the roof panel 20 via a clip (not shown). .

  The roof side bracket 30 as a vehicle shock absorber according to the present invention is interposed in the space between the roof trim 10 and the roof panel 20 on both inner sides of the roof trim 10 as shown in FIGS. Usually, it is attached to the back side of the roof trim 10 by screws, clips or the like.

  As shown in FIGS. 3 and 4, a roof side bracket 30 which is an example of a vehicle impact absorber according to the present invention is composed of an injection molded body of polypropylene resin, and a peripheral rib 31 is provided with a side wall rib 32 and a terminal. It is comprised from the wall rib 33. FIG. The vertical ribs 34 and the horizontal ribs 35 are arranged in an intersecting manner inside the peripheral ribs 31. In this embodiment, the top plate 36 is integrated in the longitudinal direction along the leading edge of the vertical ribs 34. . The thickness of each rib 31-35 is about 1 mm, and the top plate 36 is set to have a thickness of 1 mm and a width of 10 mm (see FIG. 4).

  In actual molding, molten resin is injected and filled into a cavity of an injection mold 40 that is roughly composed of a movable mold 41 and a fixed mold 42, and a draft is set. As shown in FIG. 5, the thickness of each of the ribs 31 to 35 is 1.0 mm on the side facing the roof trim 10 (indicated by t1 in the figure), and the thickness of the edge on the panel facing side is 1.0 mm. The rib thickness (indicated by reference sign t2 in the figure) is set to 1.2 mm, and it is configured so that the mold can be satisfactorily removed from the injection mold 40 by this draft. In actual molding, the molten resin is filled into the cavity from the gate 43. As shown in FIG. 6, the molten resin smoothly flows in the cavity 44 corresponding to the top plate 36. Since the resin branches from the cavity 44 corresponding to the inside to the cavity 45 corresponding to the lateral rib 35 and quickly moves, it is possible to eliminate almost all molding defects such as short shots and burrs caused by overfilling. Can significantly increase the performance.

  Conventionally, the gate 43 has been required to be set at many points. However, since the top plate 36 serving as a resin passage is set along the longitudinal direction as in the present invention, the gate 43 is formed in the end wall rib in this embodiment. It is sufficient to set two places corresponding to 33, and the mold processing of the molding die 40 can be simplified. Furthermore, as shown in FIG. 7, the top plate 36 is integrated with the edge of the vertical rib 34, and the top plate 36 is pushed out by the tip of the push pin 46 that operates at the time of demolding, thereby removing the roof side bracket 30. The moldability can be improved. Therefore, conventionally, when the push pin 46 is set, there is a problem that the set place is limited to the intersection of the vertical rib 34 and the horizontal rib 35. However, in the present invention, the set place of the push pin 46 is changed. It can be set freely, and the degree of freedom of modeling the molding die 40 can be improved.

  Next, FIGS. 8 to 10 show a modification of the present invention, which is the same as that applied to the roof side bracket 30, but is a modification in which the shape and setting location of the top plate 36 are changed. That is, in FIG. 8, the top plate 36A extends from the edge of the side wall rib 32 toward the vertical rib 34, and when the top plate 36A is set on the side wall rib 32 in this manner, As shown in FIG. 9, it is effective when the roof side bracket 30 is a two-piece type with the same molding die. As shown in FIG. 10, the top plate 36 </ b> B can be integrated over the entire surface so as to cover one side opening of the peripheral rib 31 constituted by the side wall rib 32 and the terminal wall rib 33. When integrated so as to cover the opening like the top plate 36B, there is a tendency to increase the weight, but by setting the top plate 36B over the entire surface, the effect that the resin flow is further improved. There is.

  In the embodiment described above, the structure of the vehicle shock absorber according to the present invention is applied to the roof side bracket 30 installed on the inner surface side of the roof trim 10, but it is mounted on the indoor surface side of the side wall panel of the vehicle. The present invention can also be applied to vehicle impact absorbers such as side impact pads installed on the inner surfaces of door trims, rear side trims, and the like. Furthermore, if it is the structure provided with the surrounding rib 31, the vertical rib 34, the horizontal rib 35, and the top plate 36, the variation of changing the thickness dimension and shape of the ribs 31-35 and the position and shape of the top plate 36, etc. suitably You can choose.

It is explanatory drawing which shows the installation location of the roof side bracket which is one Example of the shock absorber for vehicles which concerns on this invention. It is sectional drawing which shows the structure of the roof trim which attached the roof side bracket which is an example of the shock absorber for vehicles which concerns on this invention. It is a perspective view which shows the roof side bracket which is one Example of the shock absorber for vehicles which concerns on this invention. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. It is explanatory drawing which shows the state at the time of shaping | molding of the roof side bracket shown in FIG. It is explanatory drawing which shows the resin flow at the time of shaping | molding of the roof side bracket shown in FIG. It is explanatory drawing which shows the state at the time of the mold release after shaping | molding of the roof side bracket shown in FIG. It is a perspective view which shows the modification of the roof side bracket shown in FIG. It is explanatory drawing which shows the 2 piece removal state of the roof side bracket shown in FIG. It is a perspective view which shows the modification of the roof side bracket shown in FIG. It is sectional drawing which shows the installation location of the conventional roof trim and a roof side bracket. It is a perspective view which shows the conventional roof side bracket. FIG. 13 is a sectional view taken along line XIII-XIII in FIG. 12. It is explanatory drawing which shows the setting state of the gate at the time of shaping | molding in the conventional roof side bracket.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Roof trim 11 Base material 12 Skin 20 Roof panel 30 Roof side bracket 31 Peripheral rib 32 Side wall rib 33 Terminal wall rib 34 Vertical rib 35 Horizontal rib 36, 36A, 36B Top plate 40 Injection mold 41 Movable side mold 42 Fixed Side mold 43 Gate 44, 45 Cavity 46 Extrusion pin

Claims (2)

It is interposed between the vehicle body panel (20) and the interior trim (10). When an impact is applied to the vehicle, it can be deformed or collapsed so that the impact load can be absorbed. In the configured vehicle shock absorber (30),
The vehicle shock absorber (30) has a longitudinal rib (34) and a lateral rib (35) arranged in a lattice pattern inside a peripheral rib (31) composed of a side wall rib (32) and a terminal wall rib (33). And a top plate (36) having a predetermined width is provided along an edge portion on at least one side of the longitudinal rib (34) extending along the longitudinal direction or the side wall rib (32). The vehicle shock absorber is characterized in that the fluidity of the resin during molding is enhanced.   The vehicle impact absorber (30) is molded into a required shape by injecting and filling molten resin into the cavity of the molding die (40), and then the top plate (36) is pushed by the push pin (46). The impact absorber for vehicles according to claim 1, wherein releasability from the molding die (40) is enhanced by extruding in a die-cutting direction.

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