JPH0911323A - Bumper reinforcement by blow molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a bumper reinforcement which indicates a large reinforcing effect to a collision load from the front, a diagonal load, and a vertical load and in which the delamination between a main body plastic material and a reinforcing material and the deformation of the materials scarcely take place. SOLUTION: A blow molded hollow cylindrical bumper reinforcement into which a reinforcing material 3 of a plastic having an affinity to a plastic material constituting a main body 4 is inserted. The main body plastic material extends from the rear wall surface 4b to the front wall surface 4a to enclose the reinforcing material 3 by the end parts and is deposited on the rear wall surface 4b, and plate-shaped ribs 5 and cylindrical ribs 6 of the main body plastic material are formed alternately in the longitudinal direction of the reinforcing material 3 between the rear part of the reinforcing material 3 and the rear wall surface 4b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-strength bumper rain hose obtained by blow molding.

[0002]

2. Description of the Related Art The blow molding method has become increasingly important in the plastics industry as a method for producing large quantities of products of the same quality at low cost, and recently, bumper rain hoses have been produced by the blow molding method. It has become

[0003]

The thickness of a blow-molded product is basically substantially constant, and it is not possible to change the thickness of a specific portion (for example, to reinforce a portion by increasing the thickness). It can only be performed in a very narrow range. Therefore, it is actually impossible to reinforce necessary parts by varying the thickness of a large molded product such as a bumper reinforcement in a wide range. For example, in order to increase the load carrying strength in the front-rear direction, In addition, it is necessary to increase the thickness of the entire molded product.
Also, conventionally, a method of reinforcing a large molded product by bonding or screwing a reinforcing material such as a metal has been taken,
There were many troubles due to breakage from the reinforced part and differences in materials.

On the other hand, Japanese Patent Application Laid-Open No. 59-103725 discloses that a flat belt-shaped reinforcing core made of metal or synthetic resin having excellent rigidity is provided in a rib connecting front and rear face plates of a hollow plate obtained by blow molding. Is described. But,
When a material having a different material is internally provided as the reinforcing core material in this manner, peeling or deformation may occur over time based on the difference in the material (lack of affinity, difference in physical properties such as shrinkage), In particular, when applied to bumper reinforcements of automobiles always used in a vibration environment, it is uneasy whether stable strength characteristics can be obtained for a long time.
Further, the hollow plate body disclosed in the above publication is expected to have a large load-bearing strength against a load perpendicular to the front and rear face plates. However, such a plate-like rib is provided with a hollow cylindrical bumper reinforcement. When applied to a large load in the front-rear direction (especially when the load direction is not vertical), the cross section is generally slanted (the cross section is fringed like a parallelogram). There is also the problem of easy occurrence.

[0005]

SUMMARY OF THE INVENTION A bumper reinforcement according to the present invention has been devised in view of the above-mentioned various problems, and has a reinforcing material formed of a plastic having an affinity for a plastic material constituting a main body. Is a hollow cylindrical bumper rain hose made by blow molding. The main body plastic material extends from the rear wall surface to the front wall surface and covers the reinforcing material at the tip end thereof and is welded to the front wall surface. A plate-like rib and a tubular rib made of the main body plastic material are alternately formed between the rear part and the rear wall surface of the reinforcing material along the longitudinal direction of the reinforcing material.

As the plastic material of the bumper reinforcement according to the present invention, various materials used in the art can be used. Such plastic materials can include polyethylene, polypropylene, polycarbonate, polystyrene, ABS, and composite materials thereof. These plastic materials are compatible with each other and can be used as a body and a reinforcement for each other.

For the purpose of the present invention, it is particularly preferred that the plastic material of the main body is any of the above-mentioned exemplary plastic materials, and the reinforcing material is formed of the same plastic material as the plastic constituting the main body. Above all, polypropylene, polyethylene and AB
S resin is preferred. When the same material is used, the affinity is particularly high, the dimensions of the product are maintained, and there is no possibility of peeling, so that a useful high-strength bumper rain molded article can be obtained. Moreover, there is an advantage that the plastic molded product can be reused. Conventionally, the reuse of various plastic products has been hindered due to the inability to separate constituent materials. According to the present invention, such a problem can be solved. Therefore, the above is a very important advantage when considering the effective use of resources.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a molding process of a reinforced bumper reinforcement (automobile bumper beam). In the figure, 1 is a parison, 2 is a mold, and 3 is a reinforcing material. 1) A reinforcing material 3 is sandwiched between the molds 2. 2) The parison 1 is lowered and the mold 2 is separated (Fig. 1).
The state transitions from A) to the state in which the mold 2 is closed (FIG. 2B). 3) As usual, molding is performed while blowing air from a lower air blowing port. 4) The reinforcing material 3 sandwiched between the molds 2 is inserted into the parison 1. 5) When the mold 2 is released, a bumper reinforcement in which the reinforcing material 3 having a desired length is inserted into the main body 4 is obtained.

FIG. 2 is a cross-sectional view of the bumper rainpiece, FIG. 3A is a cross-sectional view of the bumper rainpiece of FIG. 2, taken along aa line, and FIG. As clearly shown in these figures, the plastic material of the main body 4 extends from the rear wall surface 4b to the front wall surface 4a, covers the reinforcing material 3 at the tip end thereof, and reaches the inner surface of the front wall surface 4a. Further, plate-like ribs 5 and cylindrical ribs 6 made of a main body plastic material are alternately formed between the rear portion and the rear wall surface 4b of the reinforcing member 3 along the longitudinal direction of the reinforcing member. The reinforcing members and the ribs 5 and 6 are subjected to a load in the left-right direction in FIG. 3 (specifically, a collision from the left).
Shows a large reinforcing effect. In addition, since the cylindrical rib 5 is formed between the reinforcing member 3 and the rear wall surface 4b, especially when the rib is formed to have a tapered cross section, it can withstand an oblique load or a vertical load. Shows strong reinforcing action.

[0010]

[Effect] The bumper rain hose according to the present invention is
Since a plastic material that is the same as or has affinity with the main body is used as the reinforcing material, there is little risk of delamination or deformation with the main body plastic material over time, and dimensional accuracy is extremely high and strength characteristics that are stable for a long period of time Obtainable. When the main body and the reinforcing material are made of the same plastic material, they can be collectively reduced to raw materials, so that it is extremely easy to reuse them. In addition, the main body plastic material extends from the rear wall surface to the front wall surface, wraps the reinforcing material at the front end thereof and is welded to the front wall surface, and is formed of a main body plastic material between the rear and rear wall surfaces of the reinforcing material. The ribs and the cylindrical ribs are alternately formed along the longitudinal direction of the reinforcing member, so that a large reinforcing effect can be obtained with respect to a load in the left-right direction (particularly, a collision load from the front), and in a diagonal direction. A large reinforcing effect is exhibited even with respect to the load in the vertical direction or the load in the vertical direction.

[Brief description of the drawings]

FIG. 1 is a view showing a blow molding step of a bumper rain hose according to the present invention.

FIG. 2 is a sectional view of the same bumper rain hose.

3 is a sectional view taken along a line aa (FIG. 3A) and a sectional view taken along a line bb (FIG. 3B) of FIG. 2;

[Explanation of symbols]

 3 Reinforcement 4 Main body 4a Front wall surface 4b Rear wall surface 5 Plate-shaped rib 6 Cylindrical rib

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29L 31:30

Claims (1)

[Claims] 1. A hollow cylindrical bumper reinforcement made by blow molding, wherein a reinforcing material formed of a plastic having an affinity for a plastic material constituting a main body is inserted. It extends to the front wall surface and covers the reinforcing material at the front end thereof and is welded to the front wall surface. Between the rear and rear wall surfaces of the reinforcing material, a plate-shaped rib made of the main body plastic material and a cylindrical member are formed. A rib formed by blow molding, wherein ribs are alternately formed along a longitudinal direction of the reinforcing member.