JPS642845Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to cushioning materials for vehicles, such as bumpers attached to the front and rear ends of vehicles such as automobiles, or moldings attached to both sides of the vehicle, in order to prevent damage to the vehicle. Conventionally, metal bumpers have often been used as cushioning materials for vehicles, especially automobiles, but these metal bumpers have relatively thick walls to prevent damage to the car body in the event of a vehicle collision. It requires a metal plate and is therefore quite heavy, resulting in poor fuel efficiency for automobiles. In addition, metal bumpers, etc. not only have the disadvantage of causing plastic deformation in the event of a collision, impairing the appearance of the vehicle, but also have the disadvantage that the impact of the collision is likely to propagate into the interior of the vehicle. This had the disadvantage of injuring personnel and increasing accidents. In the United States, the Federal Motor Vehicle Safety Standards (FMVSS) have been established from the standpoint of occupant safety and vehicle body protection, and in recent years, efforts have also been made in Japan to improve the rigidity of metal bumpers. As such a metal bumper, there is one shown in Figure 1, but in this figure,
A bumper beam 1 serving as a buffer member is formed into a substantially box-shaped elongated metal member in order to improve rigidity, and a cross section 2 perpendicular to the longitudinal direction has a substantially rectangular frame shape. This bumper beam 1
is configured to be attached to a vehicle (not shown) via two rod-shaped supports 3 having a shock absorbing mechanism, and also includes a support 3 for the bumper beam 1.
A rim skin 4 made of urethane and having a substantially U-shaped cross section and substantially surrounding one end of the bumper beam 1 is attached to the side where the bumper beam 1 is not attached. However, in the case of such a metal bumper, since the bumper beam 1 is formed into a substantially box shape, not only does the manufacturing process require complicated and complicated work processes such as furnace welding, but also the bumper beam 1 is formed into a substantially box shape. In general, since two metal plates are required, the weight increases considerably, and in the case of automobiles, this has the disadvantage of resulting in poor fuel efficiency. Furthermore, since the material is metal, plastic deformation in the event of a collision cannot be prevented, and furthermore, rust is likely to occur and corrosion resistance is poor, requiring a considerable amount of effort for maintenance. As an alternative to such metal bumpers, bumpers made of ordinary resin or short fiber-reinforced plastic have recently been considered. However, those made of resin have low rigidity and poor impact resistance, so they must be reinforced with metal plates or the like, which makes the manufacturing process complicated and has the drawback of poor workability. Furthermore, although the rigidity of short fiber-reinforced plastics has been improved, their impact resistance is still insufficient, and cracks are particularly likely to occur when subjected to impact, resulting in sharp fractured surfaces. This sharp fracture surface often causes secondary accidents, which poses a practical problem. An object of the present invention is to provide a cushioning material for a vehicle that has excellent mechanical strength, particularly rigidity and impact resistance, and is significantly lighter in weight. In the present invention, a cushioning member having a substantially U-shaped cross section is formed of a long-fiber reinforced thermoplastic resin made of thermoplastic resin and high pressure-resistant long fibers, and the bottom surface of the cushioning member is placed on the side of the vehicle. This object is achieved by forming reinforcing ribs that protrude vertically toward the vehicle, and by providing a cushioning resin foam between at least the cushioning member and the vehicle. Hereinafter, the present invention will be explained based on the drawings. FIG. 2 shows a bumper beam 11 as a buffer member in an embodiment of the present invention, and this bumper beam 11 is formed into an elongated shape, and a cross section perpendicular to the longitudinal direction is as shown in FIG. 3. It is formed into a roughly U-shape. The bumper beam 11 is made of a long fiber reinforced thermoplastic resin made of a thermoplastic resin and high pressure resistant long fibers. Furthermore, workability is improved by integrally molding the support 14 and the rim skin attachment hole 18. Examples of the thermoplastic resin include polyethylene, polypropylene, polycarbonate, nylon (polyamide), and mixtures thereof. The high pressure-resistant long fibers refer to long fibers that have particularly high pressure resistance, and include glass fibers, carbon fibers, nylon fibers, and the like. The long fibers made of these materials preferably have a mat-like shape, and are preferably laminated in several layers.
Here, mat refers to fibers that are not put on a loom but are piled up as strands or intertwined to form a sheet, and in particular, glass fibers that are made into a mat are called glass fiber mat. Examples of glass fiber pine include diamond pine, continuous pine, needle pine, overlay pine, and surf-es pine.
Particularly preferred is needle mat. In addition, the length of these high pressure resistant long fibers is 5 mm or more on average fiber length,
The long fiber-reinforced thermoplastic resin, preferably having a diameter of 10 to 100 mm, has a weight composition ratio of thermoplastic resin and high pressure resistant long fibers of 80/20 to 40/
Preferably it is 60. If the thermoplastic resin is greater than 80% by weight in the above weight composition ratio, the rigidity will be insufficient and the impact resistance will decrease, which is not preferable. If it is not present, it is difficult for the long fibers to flow sufficiently in the mold during integral molding, which tends to cause molding defects, which is not preferable. The bumper beam 11 is preferably manufactured from such a long fiber-reinforced thermoplastic resin in the following manner. In other words, a blank resin (a resin plate in which thermoplastic resin and long fibers are integrated in a predetermined composition ratio) with a weight equivalent to one bumper beam 11 is used.
is heated to the melting temperature of the resin, placed in a mold, and then compression molded. At this time, the molding pressure was 100Kg/
It is preferable that it is at least cm ² . Also, the molding cycle is usually 20 to 40 seconds. Note that continuous molding is also possible. At the bottom of the bumper beam 11, reinforcing ribs 12 are integrally formed vertically and horizontally to improve impact resistance so as to protrude vertically from the bottom toward the vehicle side. At this time, since the reinforcing ribs 12 are formed in a cross shape, it is possible to improve not only the impact resistance in the horizontal direction but also the impact resistance in the vertical direction. Further, as shown in FIG. 4, the bumper beam 11 is attached to the vehicle via a plate-shaped support 14 with the open side of the U-shaped cross section facing the vehicle 13.
It is attached to one end side of 3. A urethane foam 15 is filled between the bumper beam 11 and the vehicle 13 as a first cushioning resin foam to increase the impact effect. On the side of the bumper beam 11 to which the support 14 is not attached, a rim skin 16 made of urethane is provided so as to have a U-shaped cross section and substantially surround one end side of the bumper beam 11. In addition, a second
The bumper beam 11 and the vehicle body 13 are filled with urethane foam 17 as a cushioning resin foam.
Together with the urethane foam 15 provided between the two, the cushioning effect is further increased. In addition,
The cushioning resin foam may be a foam other than urethane. However, urethane foam is preferred in terms of weight reduction. The vehicle cushioning material according to the present invention has the following effects. The thermoplastic resin is reinforced with high pressure-resistant long fibers, and has excellent mechanical strength, particularly rigidity and impact strength, resulting in extremely high safety. In addition, the recess has a large restoring force against external forces such as impact, and has the effect of being less likely to cause plastic deformation. Furthermore, when the cushioning material breaks due to a collision or the like, there is no scattering of the broken part or formation of a sharp broken surface, thereby improving safety. Additionally, compared to the aforementioned metal bumpers, etc., it is extremely easy to manufacture and has the advantage of high workability, as it does not require complex work processes such as welding and can be manufactured in one step using compression molding. . In addition, it is extremely lightweight and has the effect of contributing to reducing fuel consumption in automobiles, thereby meeting the demand for resource conservation. Table 1 shows in more detail how the vehicle cushioning material according to the present invention is lighter in weight compared to conventional metal cushioning materials having the same strength. Here, the example is a bumper in which the weight composition ratio of thermoplastic resin and high pressure resistant long fibers is 60/40 and polypropylene is used as the thermoplastic resin, and the reference example is a conventional metal bumper.

【table】

【table】 [Brief explanation of the drawing]

FIG. 1 is an exploded view showing a conventional metal bumper with a part cut away, FIG. 2 is a perspective view showing the overall structure of an embodiment of the cushioning member of the vehicle cushioning material according to the present invention, and FIG. FIG. 2 is an enlarged sectional view taken along the line - in FIG. 2, and FIG. 4 is a sectional view showing a specific structure of a bumper as a cushioning material for a vehicle using the above-mentioned cushioning member. 11... Bumper beam as a buffer member, 1
2...Reinforcing ribs, 15, 17...Urethane foam as first and second cushioning resin foams, 16...Rim skin.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a vehicle cushioning material provided at the periphery of a vehicle such as the front and rear ends or both sides of the vehicle to prevent damage to the vehicle, the cushioning member having a substantially U-shaped cross section is made of thermoplastic resin. It is formed of a long fiber-reinforced thermoplastic resin consisting of high pressure-resistant long fibers, and a reinforcing rib that protrudes vertically toward the vehicle side is formed on the bottom surface of the buffer member, and at least the buffer member and the vehicle A cushioning material for a vehicle, characterized in that a cushioning resin foam is provided between the cushioning material and the cushioning material. (2) Utility Model Registration Scope of Claims In paragraph 1, the long fiber-reinforced thermoplastic resin has a weight composition ratio of thermoplastic resin and high pressure resistant long fibers of 80/20 to 40/2.
A vehicle cushioning material characterized by having a weight of 60. (3) Utility Model Registration The vehicle cushioning material according to claim 1 or 2, wherein the reinforcing ribs are integrally formed in a crisscross pattern in the vertical and horizontal directions of the cushioning member. (4) The cushioning material for a vehicle according to any one of claims 1 to 3, wherein the cushioning resin foam is a thermoplastic foam resin. (5) In any one of claims 1 to 4 of the claims for utility model registration, the vehicle cushioning material has one end attached to the vehicle with the open side having a substantially U-shaped cross section facing the vehicle. a bumper beam that is attached in a state in which reinforcing ribs are cross-shaped in the vertical and horizontal directions toward the vehicle; a first cushioning resin foam provided between the bumper beam and the vehicle; A rim skin which is formed in a U-shaped cross section on the side of the bumper beam where the support is not attached and is provided so as to substantially surround one end side of the bumper beam, and this rim skin and one end surface of the bumper beam. A cushioning material for a vehicle, comprising a second cushioning resin foam filled in a hollow portion formed.