JP2002086484A - Foamable base material for reinforcing hollow structure and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foamable base material for reinforcing a hollow structure capable of being easily molded without using an injection mold or the like or using only a simple retaining mold. SOLUTION: A plurality of rod-shaped materials 5 comprising a foamable material are prepared to be bundled into the shape corresponding to the hollow part of the hollow structure to form a reinforcing foamable base material 1. At the time of bundling of the rod-shaped materials 5, the retaining mold having the shape corresponding to the hollow part of the hollow structure is provided and a plurality of rod-shaped materials 5 are charged in the retaining mold. In such a state that a plurality of the rod-shaped materials 5 are arranged around a core material 6 formed into a cylindrical shape, they are wholly or partially heated to be melted and bonded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamable base material for reinforcing a hollow structure and a method for manufacturing the same, and mainly relates to a rocker panel, a pillar, and a roof side of a vehicle body which is constituted by a plurality of panels in a hollow shape. The present invention relates to a reinforcing foamable base material for increasing rigidity of a panel or the like and a method for manufacturing the same.

[0002]

2. Description of the Related Art A reinforcing foamable base material for increasing the rigidity of a hollow structure is provided in a hollow portion of the hollow structure, and is used by being foamed by external heating to form a foam. At this time,
In order to efficiently reinforce the hollow structure, it is preferable that the outer peripheral surface of the foam is closely adhered to the inner peripheral wall surface of the hollow portion of the hollow structure without any gap. When a gap is formed between the outer peripheral surface of the foam and the inner peripheral wall surface of the hollow portion, a difference in strength occurs between the gap portion and a portion having no gap. When an external force acts on the hollow structure, stress concentrates due to insufficient reinforcement of the gap, and a problem such as deformation of the hollow structure in the gap may occur. For this reason, a technique for injecting a foamable material into a mold for injection molding of a reinforcing foamable base material and forming the foamable base material into a shape corresponding to the hollow portion of the hollow structure has been conventionally known.

[0003]

The hollow panels (hollow structures) constituting the vehicle body include, for example, pillars, rocker panels, roof side panels, etc. The cross-sectional shapes and sizes of these hollow panels are various. It is. In order to manufacture a reinforcing foamable base material corresponding to the cross-sectional shape of these various hollow panels, it is necessary to manufacture a mold for injection molding corresponding to the number of the different shapes. There has been a problem that the production cost of the mold becomes large. The present invention has been made in view of such a problem, and does not require a molding die, or for reinforcing a hollow structure that can be easily molded into a desired shape only with a simple mold. It is an object to provide a foamable base material and a method for producing the same.

[0004]

Means for Solving the Problems A first invention of the present application for solving the above problems is a method for producing a foamable base material for reinforcing a hollow structure as described in claim 1. Since a plurality of rod-shaped members made of a foamable material are united to produce a reinforcing foamable base material, the longitudinal cross-sectional shape is flexibly adjusted by changing the relative arrangement of the plurality of rod-shaped members. be able to. Therefore, the reinforcing foamable base material corresponding to the shape of the hollow portion of the different hollow structure can be easily formed without using a molding die or the like for injection-molding the foamable material.

A second invention of the present application is a method for producing a foamable base material for reinforcing a hollow structure as described in claim 2. Since all or some of the plurality of rod-shaped members are heated and melt-bonded to each other, the plurality of rod-shaped members themselves are integrated to maintain the relative arrangement with each other. Further, among the reinforcing foamable base materials in which a plurality of rod-like materials are bound, if the rod-like materials preferably arranged on the outside are fusion-bonded, they are integrally joined to function as a binding tool. Further, it is possible to prevent the rod-shaped material from coming off from the reinforcing foamable base material and falling off. Therefore, it is not necessary to use a binding tool or the like for binding a plurality of rod-shaped members, and the reinforcing foamable base material of the hollow structure can be easily formed.

A third invention of the present application is a method for producing a foamable base material for reinforcing a hollow structure as described in claim 3. Therefore, a formwork having a shape corresponding to the hollow portion of the hollow structure may be provided, and a plurality of rod-shaped members may be put into the formwork and bound. A series of operations for making the cross-sectional shape corresponding to the hollow portion of the hollow structure can be performed at a time. In addition, when all or some of the plurality of rod-shaped members are heated, they can be melted and joined while maintaining their relative arrangement, so that the molding of the reinforcing foamable base material is facilitated. . Here, the mold for molding the reinforcing foamable base material,
For example, it can be easily formed by bending a metal plate or the like, and its manufacturing cost can be kept low, unlike the case of using a conventional mold for injection molding.

A fourth invention of the present application is a method for producing a foamable base material for reinforcing a hollow structure as described in claim 4. Therefore, by arranging a plurality of rod-shaped members around the columnar core member and binding them, only the rod-shaped members arranged on the inner wall surface side (outside) when disposed in the hollow portion of the hollow structure are provided. And a foaming substrate for reinforcement. When the reinforcing foamable base material thus configured is heated and foamed, only the rod-shaped material disposed around the core material adheres to the inner wall surface of the hollow structure to reinforce. The rod-shaped material in the center part, which is far from the inner wall surface of the hollow structure and is not significantly involved in the reinforcement, can be replaced with the core material, and the amount of the rod-shaped material required for manufacturing the reinforcing foamable base material can be reduced.

A fifth invention of the present application is a foamable base material for reinforcing a hollow structure as described in claim 5. The reinforcing foamable base material configured as described above can flexibly adjust its longitudinal cross-sectional shape by changing the relative arrangement of the plurality of rod-shaped members, and is used for injection-molding the foamable material. It is possible to easily form a shape corresponding to the hollow portion of a different hollow structure without using a molding die or the like.

A sixth invention of the present application is a foamable base material for reinforcing a hollow structure as described in claim 6. In the reinforcing foamable base material configured as described above, a part or the entirety of the plurality of rod-shaped materials is melt-bonded to be integrated, and the relative positions of each other are maintained. Therefore, it is possible to easily form without requiring a binding tool or the like for binding a plurality of rod-shaped members.

[0010]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an appearance of a reinforcing foamable base material 1 according to an embodiment of the present invention. 2 to 4 show the reinforcing foamable base material 1 in the present embodiment.
As shown in the figure, the hollow panel 2 of the vehicle body is disposed along the longitudinal direction and becomes a foam 9 by heating to enhance the rigidity of the hollow panel 2 to reinforce it. As shown in FIG. 1, the reinforcing foamable base material 1 has a plurality of rod-shaped materials 5 made of a foamable material arranged around a columnar core material 6 and bound, and has a cross-sectional shape perpendicular to the longitudinal direction. It is configured to have a substantially triangular shape. In the present embodiment, the plurality of rod-shaped members 5
Are formed as long columns having the same cross-sectional shape. The core member 6 is formed as a hollow columnar body (cylindrical body) having a circular cross section larger than that of the rod-shaped member 5 and having a length substantially equal to that of the rod-shaped member 5. By forming the core material 6 as a hollow columnar body,
It is possible to reduce the amount of the rod-shaped material 5 necessary for molding the reinforcing foamable base material 1 and to reduce the weight of the reinforcing foamable base material 1. Therefore, the production cost of the reinforcing foamable base material 1 can be reduced, and furthermore, when mounted on the body of the vehicle, the entire vehicle becomes lighter, so that fuel efficiency can be reduced.

In this embodiment, fusion bonding is used as a binding means for binding a plurality of rod-shaped members 5. That is, the plurality of bar-shaped members 5 are joined and bound by heating and melting. Here, when heating the plurality of rods 5, at least a part thereof is heated to such an extent that the rods 5 do not come off and fall off from the reinforcing foamable base material 1 formed by binding them. It is preferred that they are melt-bonded.
For example, a plurality of rods 5 forming the reinforcing foamable substrate 1
Among them, if only the outermost rod-shaped members 5 (the inner wall surface side of the hollow panel 2) are melt-bonded to each other, the rod-shaped members 5 do not come off from the reinforcing foamable base material 1 and fall off. Of course, all of the plurality of rod-shaped members 5 can be melt-bonded to each other and bound to form the reinforcing foamable base material 1.

The rod-shaped material 5 is preferably formed of a synthetic resin-based foamable material mixed with a foaming agent which foams at a temperature of about 110 ° C. to 190 ° C. Further, a fibrous substance such as glass fiber is preferably used. It is preferably formed of a foamable material that is mixed and foamed at a temperature of about 110 ° C. to 190 ° C. to become a highly rigid foam. Foamable materials having such adhesive properties and having high rigidity are described in, for example, JP-A-8-208871 and JP-A-11-158313.
No. 6,009,036.

FIG. 2 is a sectional view perpendicular to the longitudinal direction of the hollow panel 2, and shows a state in which the reinforcing foamable base material 1 is disposed in the hollow portion 7 of the hollow panel 2. As shown in FIG. 2, the hollow panel 2 of the vehicle body includes an inner panel 3 and an outer panel 4 having flange portions 3 f of both panels.
At 4f, it is formed as a hollow structure by joining by spot welding. The cross-sectional shape perpendicular to the longitudinal direction of the hollow panel 2 is substantially triangular, and as described above, the cross-sectional shape of the reinforcing foamable base material 1 is configured to be substantially triangular corresponding thereto. An appropriate gap is provided between the inner peripheral wall surface of the hollow portion 7 and the outer peripheral edge of the reinforcing foamable base material 1. For example, when the vehicle body is immersed in the paint tank, The paint is configured to flow smoothly on the inner peripheral wall surface of the hollow portion 7 of the hollow panel 2.

FIG. 4 is a cross-sectional view of the hollow panel 2 and the reinforcing foam base 1 taken along the line AA in FIG. 2, and the reinforcing foam base 1 extends along the longitudinal direction of the hollow panel 2. Shows the state of being attached. In the present embodiment, a pair of mounting members 8a and 8b are mounted at predetermined intervals in the longitudinal direction of the hollow portion 7 of the hollow panel 2. The pair of mounting members 8a and 8b are formed by bending a flat metal plate at a right angle. When attaching the reinforcing foamable base material 1 to the hollow portion 7 of the hollow panel 2, before the inner panel 3 and the outer panel 4 are spot-welded at their flange portions 3f, 4f, first, a pair of the attaching members 8 are provided.
a, 8b are attached to the inner panel 3 by spot welding at predetermined intervals, and then the reinforcing foamable base material 1 is held between the attachment members 8a, 8b. The pair of mounting members 8a and 8b are mounted on the inner panel 3 by spot welding, screwing, clipping, welding, bonding, or the like.
It can be performed by various attachment means such as a magnet.
Further, the pair of attachment members 8a and 8b can be formed of various materials such as heat-resistant synthetic resin and wood, in addition to the flat metal plate.

FIG. 3 shows the reinforcing foam base material 1 shown in FIG.
Shows a state in which the hollow panel 2 is reinforced by foaming to form a foam 9. The reinforcing foamable base material 1 is foamed by external heating, for example, by external heating at the time of baking coating of a vehicle body having the hollow panel 2, and becomes a foam 9. Then, the peripheral portion of the foam 9 closely adheres to the inner peripheral wall surface of the hollow portion 7 without any gap. In order to bring the peripheral portion of the foam 9 into close contact with the inner peripheral wall surface of the hollow portion 7, the inner peripheral wall surface side of the hollow portion 7 (reinforcing It may be sufficient if the bar-shaped material 5 is arranged only on the outside of the base material 1). Therefore, in the present embodiment, the core material 6 is used by substituting the core material 6 for the portion near the center of the reinforcing foamable base material 1 which is not so closely involved in reinforcing the inner peripheral wall surface of the hollow portion 7. The amount of the bar 5 is reduced. The core 6 can be made of various materials such as synthetic resin, metal, wood, and the like.

Hereinafter, a method for producing the reinforcing foamable base material 1 will be described.
This will be described with reference to FIGS. As shown in FIGS. 5A and 5B, the foamable material is continuously extruded from an extrusion opening of a molding die 21 of an extruder 20, and an extruded product 22 is formed. Then, by rotating the rotary cutter 23 disposed near the extrusion port of the forming die 21, the extruded product 22 is cut into a required size, and a plurality of bar-shaped members 5 are prepared. In order to prepare the plurality of rod-shaped members 5, a method other than extrusion molding of a foamable material may be used, and the means is not limited.

Next, as shown in FIG. 7, a mold 10 corresponding to the shape of the hollow portion 7 of the hollow panel 2 is prepared. As shown in FIG. 6, the formwork 10 is composed of a pair of formwork plates 10a and 10b formed by bending a metal plate or the like, and has a substantially triangular vertical cross section in the longitudinal direction. It is formed as a hollow cylindrical body. The mold frame plate 10a constitutes one of the members obtained by substantially half-dividing a cross-sectional shape (substantially triangular shape in the present embodiment) perpendicular to the longitudinal direction of the mold frame 10 so as to be bilaterally symmetrical. The plate 10b constitutes the other of the obtained members. A pair of form plates 10
a, 10b are connected to one opening of the mold 10 and have substantially the same shape (substantially triangular shape) as the opening.
In addition, a support plate 12 made of a heat-resistant synthetic resin or metal is provided. At the center of the support plate 12,
A core material installation part 11 protruding from the support plate 12 in a cylindrical shape is provided.

As shown in FIG. 7, the core material 6 is inserted into the inside of the mold 10 from the opening of the mold 10 (the opening where the support plate 12 is not installed), and Will be installed. The core material installation part 11 is protrudingly provided in a columnar shape having an outer diameter substantially equal to the inner diameter of the cross section of the hollow columnar body (cylindrical body in the present embodiment) constituting the core material 6. It is installed by engaging the end with the core material installation section 11. Formwork 10
Opening (opening on the side where support plate 12 is not installed)
Thereafter, a plurality of rod-shaped members 5 are supplied so as to be arranged around the core member 6. The quantity of the bar 5 to be charged is
It is determined from the required amount for forming the reinforcing foamable substrate 1. In this way, in a state in which the plurality of bar-shaped members 5 are arranged around the core member 6, the lower portion is supported by the support plate 12 while the side portions are supported and filled by the mold 10.

Next, the plurality of rod-shaped members 5 are heated, melt-bonded to each other, and bound. In order to heat the plurality of bar members 5, the mold 10 filled with the plurality of bar members 5 and the core member 6 is externally heated. In order to heat the mold 10, various heating means can be used, such as blowing hot air, using an electric heating coil, or providing a heating chamber and passing the heating chamber. In addition, instead of heating the mold 10 and indirectly heating the rod 5, the plurality of rods 5 are directly heated by blowing hot air or steam into the interior of the mold 10. You may carry out fusion joining. The temperature at which the plurality of rod-shaped members 5 are heated is a temperature at which the foamable material forming the rod-shaped members 5 does not foam, and is melted and adhered (for example, a temperature of about 80 ° C.). preferable.
Further, as described above, if only the rod-shaped material 5 disposed outside of the plurality of rod-shaped materials 5 constituting the reinforcing foamable base material 1 is melted and joined, the bar-shaped material 5 becomes the reinforcing foamable base material. It is not necessary to melt and join all of the plurality of rod-shaped members 5 because they do not fall off from one and fall off. Of course,
All of the plurality of rod members 5 can be melt-bonded to form the reinforcing foamable material 1.

As shown in FIG. 8, the reinforcing foamable base material 1 formed by melting and joining the plurality of rod-shaped members 5 is pushed up by the take-out device 13 and taken out from the mold 10. The take-out device 13 is connected to substantially the center of the lower surface of the support plate 12, and is a device for taking out the reinforcing foam base material 1 by moving the support plate 12 in the longitudinal direction of the formwork 10. . As the take-out device 13, for example, a cylinder or the like using a hydraulic, pneumatic, electric motor or the like as a driving source can be used. The reinforcing foamable base material 1 can also be taken out by dividing the mold 10 into mold plates 10a and 10b and removing the mold. At this time, it is preferable to apply a release agent or the like to the inner wall surface of the mold 10 so that the reinforcing foamable base material 1 is easily removed from the mold 10. In this manner, the reinforcing foam base material 1 is removed from the mold 10.
Is taken out, a reinforcing foamable base material 1 having a desired shape can be obtained.

The formwork 10 for forming the reinforcing foamable base material 1 can be easily formed by bending a metal plate or the like. Unlike the mold for injection molding, such a simple mold 10 can reduce the manufacturing cost at a low cost. That is, even when the cross-sectional shape and size of the hollow panel 2 are variously different, the mold 10 having a shape corresponding to the shape can be manufactured at low cost, and the manufacturing cost of the reinforcing foamable base material 1 can be reduced.

In the embodiment, the fusion bonding is used as a means for binding the plurality of rod-shaped members 5, but various other means can be applied. For example, as shown in FIG. 9, a plurality of rod-shaped members 5 can be bound by winding them around a metal band 14. In the reinforcing foamable base material 1 formed by binding in this manner, the cross-sectional shape of the hollow portion 7 is variously varied by adjusting the shape of the metal band 14 to the shape of the hollow portion 7 of the hollow panel 2. Can be easily handled. In this case,
There is no need for a step of charging the rod-shaped material 5 into the mold 10 and heating. As means for binding the plurality of rod-shaped members 5,
Various means can be applied, such as bonding the rod-shaped members 5 to each other with an adhesive or winding them with wires.

In the embodiment, the example in which the plurality of rod-shaped members 5 are arranged around the core material 6 and bound is shown. However, the reinforcing foamable base material 1 may be formed without using the core material 6. it can.
For example, by tying only a plurality of rod-shaped members 5, it is possible to form the reinforcing foamable base material 1 according to the shape of the hollow portion 7. Alternatively, the core material 6 is removed from the reinforcing foamable base material 1 in which the plurality of rod-shaped materials 5 are bound around the core material 6, and the reinforcing foamable base material formed of only the plurality of rod-shaped materials 5 is used. Material 1 can also be obtained.

In the above embodiment, the case where the hollow structure is a hollow panel such as a rocker panel, a pillar, and a roof panel of a vehicle body is exemplified, but the present invention is not limited to this.
The present invention can be applied to a hollow structure other than a vehicle body, for example, a hollow structure forming a building such as a building or a ship.

[0025]

As described above, according to the present invention, even in the case where the cross-sectional shape of the hollow structure is variously different, only a simple mold or a mold is not used. A reinforcing foamable substrate of a hollow structure corresponding to the shape can be obtained. Since there is no need to prepare a molding die or the like for injection molding corresponding to the cross-sectional shape of the hollow structure, the production cost of the reinforcing foamable base material can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a reinforcing foamable base material according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view perpendicular to the longitudinal direction of the hollow panel,
The state in which the reinforcing foamable base material is disposed in the hollow portion of the hollow structure is shown.

FIG. 3 is a cross-sectional view showing a state in which a hollow panel is reinforced by foaming a foaming substrate for reinforcement into a foam.

FIG. 4 is a cross-sectional view of the hollow panel and the reinforcing foam base material in FIG. 2 taken along the line AA, showing a state in which the reinforcing foam base material is attached along the longitudinal direction of the hollow panel.

FIG. 5 is an explanatory view showing an embodiment in which a rod-shaped material is molded by an extrusion molding machine.

FIG. 6 is an explanatory view showing a structure of a mold.

FIG. 7 is an explanatory view showing an aspect in which a plurality of rod-shaped members are put into a mold.

FIG. 8 is an explanatory view showing an embodiment of taking out a reinforcing foamable base material from a mold.

FIG. 9 is a perspective view showing a reinforcing foamable base material obtained by binding rod-shaped members with a metal band.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Reinforcing foam base material 2 ... Hollow panel 3 ... Inner panel 4 ... Outer panel 3f, 4f ... Flange part 5 ... Bar-shaped material 6 ... Core material 7 ... Hollow portion 8a, 8b ... Mounting member 9 ... Foam 10 ... Mold Frames 10a, 10b ... Form plate 11 ... Core material installation part 12 ... Support plate 13 ... Removal device 14 ... Metal band 20 ... Extruder 21 ... Molding die 22 ... Extruded product 23 ... Rotary cutter

Claims (6)

[Claims] 1. A method for producing a reinforcing foamable base material for a hollow structure, which is provided in a hollow portion of the hollow structure and foams by external heating to form a foam, thereby reinforcing the hollow structure. Preparing a plurality of rod-shaped members made of a foamable material, binding the plurality of rod-shaped members into a shape corresponding to the hollow portion of the hollow structure to form a reinforcing foamable base material, reinforcing a hollow structure; Method for producing foamable base material for use. 2. The method for producing a foamable base material for reinforcing a hollow structure according to claim 1, wherein all or some of the plurality of rods are heated when binding the plurality of rods. A method for producing a foamable base material for reinforcing hollow structures that are melt-joined and bound together. 3. The method for producing a foamable base material for reinforcing a hollow structure according to claim 1, wherein, when binding a plurality of rod-shaped members, a mold having a shape corresponding to a hollow portion of the hollow structure. A method for producing a reinforcing foamable base material for a hollow structure, in which a plurality of rod-shaped members are put into a frame, and all or some of the plurality of rod-shaped members are heated and melt-bonded to each other. 4. The method for producing a foamable base material for reinforcing a hollow structure according to claim 1, wherein a plurality of rod-like members are bundled around a columnar core material when binding the plurality of rod-like members. A method for producing a foamable base material for reinforcing a hollow structure, wherein the rod-shaped members are arranged and bound. 5. A reinforcing foamable base material for a hollow structure, which is provided in a hollow portion of the hollow structure and foams by external heating to form a foam, thereby reinforcing the hollow structure. A foamable substrate for reinforcing a hollow structure, wherein a plurality of rod-shaped members made of a material are bound in a shape corresponding to the hollow portion of the hollow structure. 6. The reinforcing foamable base material for a hollow structure according to claim 5, wherein all or a part of the plurality of rod-shaped members are united by fusion bonding to each other. Foamable base material.