JPH02178007A - Manufacture of foam-filled bumper - Google Patents

Abstract

PURPOSE:To improve the working efficiency, to save the labor, and to reduce the production cost by a method wherein openings, with which a face member and a reinforcement are communicated each other, are made and fluid foam stock is poured through the openings. CONSTITUTION:When fluid uncured foamable resin W is poured with a pouring nozzle 7 through a rear opening 22 in a reinforcement 2, the uncured foamable resin W enters through a front opening 21 in a hollow space 11 between a face member 1 and the reinforcement 2 and starts foaming by being externally heated with a face backing mold 6. Though the uncured foamable resin W, which is poured in the reinforcement 2, also starts foaming, since the interior temperature of the hollow space 11 is lower than that of the reinforcement 2, the resin in the hollow space 11 between the face member 11 and the reinforcement 2 expands highly, while the resin in the reinforcement 2 expands low so as to fill both the space and the reinforcement with foams 3 and 4.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a foam-filled bumper.

(Prior Art) In recent years, plastic bumpers have been used to reduce the weight of bumpers, and as shown in FIG. 4, a reinforcement 2 which is a strength member is surrounded by a face member 1; Face member l and reinforcement 2
A buffer foam 3 is interposed in the space between the reinforcement 2 and a foam 4 is provided inside the reinforcement 2 in order to improve the rigidity and buckling strength of the reinforcement 2. However, when inserting the preformed foam 4 into the reinforcement 2 and fitting it into the face member 1, the preformed foam 3 is inserted between the face member l and the reinforcement 2. The work of assembling the parts by interposing them between the parts has the disadvantage that it requires a large number of assembly steps and increases the manufacturing cost. Also, foams 3 and 4
If it is installed internally, it is not integrally joined to the face member 1 and the reinforcement 2, so there remains the problem that energy absorption performance is insufficient. Therefore, the present applicant has created a structure in which the face member 1, the void space between the reinforcement 2, and the foam members 3 and 4 that are housed inside the reinforcement 2 are internally foamed, and the bumper member is integrated with the foam members. (Patent application 1986-13)
No. 9881).

(Problems to be Solved by the Invention) An object of the present invention is to provide a method capable of manufacturing a bumper that is integral with the interior foam body in one step.

(Means for Solving the Problems) The present invention includes forming an opening in the reinforcement that communicates with the cavity of the face member and the reinforcement, and injecting a fluid foam material through the opening. This method was based on the fact that the voids to be filled with foam were filled with foam material continuously, and the bumper parts were integrated by the internal foaming, making it a closed-section reinforcement. , and a face member having a substantially U-shaped cross section that surrounds the face member and the reinforcement are fixed, and a flowable uncured foam material is inserted into the void space between the face member and the reinforcement through an opening provided in the reinforcement, and a face member having a substantially U-shaped cross section. A method of manufacturing a foam-filled bumper includes filling a void in a hosement and curing the foam.

According to the present invention, the face member and the reinforcement are integrated by the foam that is foamed and filled in the inner cavity, and the rigidity and buckling strength are improved by filling the reinforcement with the foam. However, it is also possible to change the foaming degree of the foam depending on the position of the void, and in that case, the foam filled in the void between the face member and the reinforcement may be placed inside the reinforcement. It is preferable that the foam be filled with a higher foaming rate than the foam to be filled. As a result, the small load of a light collision is absorbed by the low-rigidity foam between the face member and the reinforcement, and the large load of a heavy collision is absorbed by the high-rigidity foam in the reinforcement.

Hereinafter, the present invention will be described in detail based on specific examples shown in the accompanying drawings.

(Example) In Fig. 1, the same foam material W is used, but by controlling the foaming temperature, foaming in the voids of the face member L and the reinforcement 2 is promoted, and foaming inside the reinforcement 2 is promoted. This is a cross-sectional explanatory diagram showing an outline of the method of suppressing the heat, in which the face member l has a concave portion of the same shape, the heatable face receiver is attached to the mold 6, and the rear opening of the reinforcement 2 is fixed with the holding member 5. Closed due to

As shown in FIG. 2, the reinforcement 2 has a space 1 between the face member l and the reinforcement 2.
1, and a rear opening 22 that communicates between the outside and the inside of the reinforcement 2.

Therefore, when the uncured foamable resin W having fluidity is injected into the reinforcement 2 from the rear opening 22 using the injection nozzle 7, the gap 11 between the face member l and the reinforcement 2 is injected through the correction opening 21. The uncured foamable resin W enters into the face holder, and the face holder starts foaming due to external heating of the mold 6. At the same time, the uncured foamable resin W injected into the reinforcement 2 also starts foaming, but the void 1
Since the internal temperature of the reinforcement 2 is lower than the internal temperature of the reinforcement 1, the space 11 between the face member l and the reinforcement 2 is highly foamed, but the inside of the reinforcement 2 is low foamed, and the foam 3 and 4 will be filled.

FIG. 3 shows a method in which a high foaming material W1 is injected into the space 11 between the face member l and the reinforcement 2, and a low foaming material W2 is injected into the reinforcement 2. It communicates with the high foaming material 11 tank 9 and the low foaming material w2 tank IO through the tank 9. Therefore, at the initial stage of injection, the filling nozzle 7 is injected into the space 11 between the face member l and the reinforcement 2 through the front opening 21 of the reinforcement 2, and foaming is then carried out (see FIG. 3(a)). , the injection nozzle 7 is retreated, and the low foaming material W2 is injected into the reinforcement 2 and foamed (see Fig. 3).
b)). Note that the same members as in FIG. 1 are designated by the same numbers.

(Effects of the Invention) As is clear from the above description, according to the present invention, an opening communicating with the face member and the reinforcement is formed,
Since the foam material having fluidity is injected through the opening, the foams 3 and 4 can be injected continuously, resulting in extremely high work efficiency, labor saving, and cost reduction.

Moreover, the voids to be filled with foam are filled with the foam material continuously, and the foam material foamed and filled in the internal voids integrates the face member and the reinforcement. Filling with foam can improve rigidity and buckling strength.

It is also possible to change the degree of foaming of the foam depending on the position of the void, so that the foam filled in the void between the face member and the reinforcement is the same as the foam filled in the reinforcement. The foaming rate is higher than that of the body, so that the small load from a light collision is absorbed by the low-rigidity foam between the face member and the reinforcement, and the large load from a heavy collision is absorbed by the high-rigidity foam inside the reinforcement. be able to.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional explanatory view showing the steps of the first embodiment of the method of the present invention, FIG. 2 is a cross-sectional view showing the assembled state of the reinforcement used in the present invention, and FIG. 3 (aXb) is an explanatory view of the present invention. FIG. 4 is a vertical cross-sectional explanatory view showing the steps of the second embodiment of the method, and FIG. 4 is a cross-sectional view schematically showing a foam-filled bumper. l...face member, 2...reinforcement,
3 and 4...foam, 21, 22...opening, 7.
...Injection nozzle.

Claims (1)

[Claims] 1. A reinforcement with a closed cross section and a face member surrounding it with a substantially U-shaped cross section are each fixed, and a fluidized uncured foam is passed through an opening provided in the reinforcement. A method for manufacturing a foam-filled bumper, comprising filling a material into a void between the face member and the reinforcement, and a void within the reinforcement, and curing the material. 2. The method according to claim 1, wherein the foam filled into the space between the face member and the reinforcement has a higher foaming rate than the foam filled into the reinforcement.