JPH08192434A - Molding of cover integrated foam molded object - Google Patents

Abstract

PURPOSE: To certainly mold a cover integrated foam molded object having a regular shape by sufficiently expanding a cover. CONSTITUTION: A molding wire 30 made of a shape memory alloy is attached to the interior of the cover 10 housed in a mold 50 along the seam 18 thereof. When a foamable filler 20 is injected into the cover 10, the molding wire 30 heated by the heat of the foaming reaction of the filler is deformed to be restored to a memory shape and the cover 10 is expanded into a predetermined shape by the restoration force of the wire to come into close contact with the inner wall of the mold 50. Since the molding of the cover is performed by the shape restoration force of the shape memory alloy stronger than the foaming expansion force of the foamable filler 20, the cover 10 can be certainly expanded into a regular shape.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a cover-integrated foam molded article which is molded into a predetermined shape by injecting a foamable filler into the inside of the cover like a headrest of an automobile. .

[0002]

2. Description of the Related Art Molding of a cover-integrated foam molded article as described above is performed in the following procedure. First, a cover of the headrest is formed by stitching and inverting a plurality of pieces of cloth cut into a predetermined shape, and the cover is housed in a molding die and spread along the inner wall surface of the molding die. Be positioned at. In this state, the expandable filler is injected into the cover to expand it, and the expansion force spreads the cover to bring it into close contact with the inner wall of the molding die.
Fill the inside of the cover with a foamable filler. Then, after the foamable filler is cured, a headrest having a predetermined shape can be obtained.

[0003]

However, since the seam allowance is bent inward at the seam portion of the cover, a repulsive force against bending is generated at the seam portion, and the seam portion is inward. There is a habit of trying to dive into. Therefore, the seam portion of the cover may not be sufficiently stretched only by the expansion force of the expandable filler. In particular, when the seams correspond to the corners and edges of the mold and are designed to be bulged outward, the degree of bending of the seams is large, and thus the bulging becomes more difficult. As described above, in the conventional molding method, the cover cannot be surely expanded into the predetermined shape, and the headrest may not be formed into the predetermined shape.

The present invention was devised in view of the above circumstances, and it is an object of the present invention to ensure that a cover-integrated foam molded article can be reliably molded into a regular shape by sufficiently expanding the cover. is there.

[0005]

According to a first aspect of the present invention, an easily deformable bag-shaped cover is housed in a mold, and a foaming filler is injected into the inside of the cover to expand the cover by a foaming action. In a molding method of a cover-integrated foam-molded article, a cover-integrated foam-molded article obtained by filling and curing the foamable filler to obtain a cover-integrated foam-molded article, a mold before injection of the foamable filler. A characteristic is that a molding member made of a shape memory alloy is provided inside the inner cover, which can be restored to the shape along the inner wall surface of the molding die by being heated by the foaming reaction heat of the foaming filler. Have.

According to a second aspect of the present invention, in the first aspect of the present invention, the cover is formed by sewing and the forming member has a wire shape, and the forming member has a seam allowance folded back to the inside of the cover. It is characterized in that it is configured so that it can be pulled out when sandwiched between them.

[0007]

According to the invention of claim 1, when the expandable filler is injected into the cover, the molding member heated by the foaming reaction heat is deformed and stored in advance, that is, along the inner wall of the mold. Restored to the desired shape. The restoring and deforming forming member spreads the cover from the inside to the outside to bring the cover into close contact with the inner wall surface of the forming die. A foaming filler is filled in the spread cover.

According to the second aspect of the invention, when the molded member is restored to the memory shape, the cover is expanded by pushing the seam outward. Since the molded member is sandwiched between the seam allowances and is held along the inside of the seam without shifting from the seam, a highlight condition occurs in which the molded member shifts to the side of the seam and protrudes to the outside of the cover. There is no danger of After molding, the molded member can be easily deformed when the temperature of the molded member decreases, so that the molded member can be removed from the cover by deforming it along the seam and removing it from the seam allowance.

[0009]

According to the first aspect of the present invention, since the shape restoring force of the shape memory alloy, which is stronger than the expansion force of the expandable filler, is used as a means for expanding the cover into a predetermined shape, the cover is molded. The power is great. Therefore, even if the seams correspond to the corners and edges of the cover, the cover can be sufficiently widened, and the cover-integrated foam molded article can be reliably molded into a regular shape.

According to the second aspect of the present invention, since the molded member is integrally held by the cover, the molded member and the cover are not displaced in position when the molded member is restored and deformed, and the cover is prevented. Can be reliably molded into a regular shape. Further, since there is no possibility that the molding member shifts to the side of the seam and protrudes to the outside of the cover, a highlight state does not occur, and in this respect also, it is possible to surely mold the cover into a regular shape. . Further, since the molded member can be removed from the cover after the cover-integrated foam molded product is molded, the cost can be reduced by reusing the molded member.

[0011]

EXAMPLE An example in which the present invention is applied to the molding of a headrest of an automobile will be described below with reference to FIGS.

Headrest (foam molded body with integrated cover)
1 has a back surface and left and right side surfaces that are substantially flat, and has a shape that smoothly curves from the upper surface to the front surface to the lower surface. The cover 10 and the foamable filler 2 filled in the cover 10
0, a forming wire (forming member) 30 for expanding the cover 10 to the above shape, and a stay 40 for attaching to the backrest of the seat.

The cover 10 is formed by sewing a top plate 11 and a gusset 12 obtained by cutting a cloth into a predetermined shape shown in FIG. The top plate 11 constitutes an upper surface, a front surface and a lower surface of the headrest. A plurality of notches 13 for positioning are formed on the outer periphery of the top plate 11. In a portion corresponding to the lower surface of the top plate 11, a notch 14A that is long in the lateral direction (the left-right direction in FIG. 2) and notches 14B and 14B that are T-shaped from both ends of the notch 14A are made. A molding port 14 that can be opened with a wide width is formed. Similarly, in the portion corresponding to the lower surface of the top plate 11, a plurality of positioning holes 15 are formed along the molding port 14, and a through hole 16 through which the stay 40 can penetrate is formed. On the other hand, the gusset 12 constitutes the back surface and left and right side surfaces of the headrest. A top plate 11 is provided on the outer circumference of the camachi 12.
Positioning notch 13 that can be aligned with the notch 13
Are formed. The top plate 11 and the gusset 12 are
The notches 13 and 13 are aligned with each other, and a predetermined seam allowance 17 is secured for sewing. At this time, the top plate 1
As shown in FIG. 3, 1 and the sill 12 are turned over, and the seam allowances 17, 17 are in a state of protruding outward. Top 11
The forming wire 30 is attached to the cover 10 after the sickle 12 is sewn together.

The forming wire 30 is made of a shape memory alloy. The forming wire 30 is formed into a linear shape having a predetermined length, and has hooks 31 and 31 each having a thin plate ring shape at both ends thereof.
Are integrally formed. The forming wire 30 has a top plate 11 when the cover 10 spreads in a regular shape.
A shape that matches the three-dimensional shape along the seam 18 between the and the gusset 12 is set as the memory shape. Further, the temperature at which the molding wire 30 restores to the memorized shape is set to a temperature that can be reached when the foaming reaction heat generated during foaming of the foamable filler 20 described later is heated as a heat source.

As shown in FIG. 7, the forming wires 30 are arranged along the seams 18 and overlap each other 2
It is sandwiched between the seam allowances 17, 17. Then, the tack pin 35 having the shape shown in FIG. 6 is penetrated into the two seam allowances 17, 17 at a plurality of appropriate positions along the seam 18 on the outer peripheral side of the forming wire 30, and both seam allowances 1 are formed.
Close 7, 17 together. Thereby, the forming wire 30
Is held along the seam 18 and sandwiched between the seam allowances 17, 17 at the inner position thereof.

Since the attaching work of the forming wire 30 is performed at room temperature lower than the temperature at which the shape restoration is started, the forming wire 30 can be freely deformed into an arbitrary shape, and therefore, the forming wire 30 can be formed. The workability of attaching the wire 30 is excellent.

In this way, the molding wire 30 is covered by the cover 1.
After mounting on 0, the cover 10 is turned inside out and the forming wire 30 is accommodated inside the cover 10 (see FIG. 9). At this time, since the forming wire 30 is deformable as described above, the work of reversing the cover 10 can be easily performed. After the cover 10 is inverted, as shown in FIG. 8, the hooks 31, 31 at both ends of the forming wire 30 are pulled out from the forming port 14 on the lower surface of the cover 10 to the outside.

Next, the upper end of the stay 40 for mounting the backrest is accommodated in the cover 10, and the lower end is penetrated through the through hole 16.
To the outside of the cover 10. Then, the cover 10 is housed in the molding die 50 in an upside down posture,
The molding port 14 of the cover 10 is aligned with the opening 51 on the upper surface of the molding die 50 (see FIG. 13). In addition, stay 4
The elastic plate 53 supported by the bracket 52 is held in a predetermined posture by a bracket (not shown) with the protruding end of 0.
Is inserted into the molding port 14 of the cover 10 (see FIG. 10).

A plurality of cover-holding bosses 54 are formed on one surface of the elastic plate 53, and one forming wire-holding boss 55 is formed on the opposite surface. The positioning hole 15 of the cover 10 is fitted into the boss 54 for holding the cover, and the hooks 31, 31 at both ends of the forming wire 30 are overlapped and fitted in the boss 55 for holding the forming wire (see FIG. 11). reference). At this time, the forming wire 30
In order that the hooks 31 and 31 are not twisted, predetermined surfaces of the front and back surfaces of the hooks 31 and 31 are oriented to face the elastic plate 53. The front and back of the hook 31 can be identified by a means such as color-coding both sides.

The molding die 50 has an air vent hole 50A which vertically communicates the inside and outside of the molding die 50 at a position where the lower surface and the back surface contact each other and a position where the lower surface is connected to the front surface.
(See FIG. 13), and an air vent hole 50B (see FIG. 14) that connects the inside and outside of the molding die 50 in the left-right direction is formed at the edge portion where the side surface and the front and rear surfaces are in contact with each other.

When the cover 10 is set on the molding die 50,
The elastic plate 53 is bent from the state shown in FIG. 12A as viewed from above as shown in FIG.
The molding opening 14 is greatly expanded, and the foamable filler 20 is injected into the inside of the cover 10 in this state. Effervescent filler 20
Expands and expands inside the cover 10.

The foaming reaction heat is generated along with the foaming of the foamable filler 20, and the molding wire 3 is generated by the foaming reaction heat.
0 is heated. Then, when the shaping wire 30 is heated to a predetermined shape restoration temperature, it starts to deform so as to restore the shape stored in advance. The forming wire 30 pushes the portion of the seam 18 outward while moving relative to the cover 10 in the direction along the seam 18.
This causes the cover 10 to be widely spread with each surface being tensioned between the seams 18. Then, finally, the seam 18 of the cover 10 is aligned with the corner edge portion of the molding die 50, and each surface of the cover 10 is brought into close contact with the inner wall of the molding die 50.

In the meantime, the expanding foaming filler 20 pushes the cover 10 from the inside to the outside due to its expanding force, and cooperates with the forming wire 30 to expand the cover 10. Then, the foamable filler 20 spreads over the entire area of the cover 10 and is filled without any gap. After this, cover 1
0 is taken out from the molding die 50, the elastic plate 53 is taken out from the cover 10 and aged for a predetermined time (FIG. 15), and the curing of the expandable filler 20 is waited.

While the expandable filler 20 is being hardened, the forming wire 30 is naturally cooled and is cooled to room temperature, and can be easily deformed into an arbitrary shape. Therefore, when the foaming filler 20 is hardened and the forming wire 30 is pulled by grasping the hook 31 facing the forming opening 14 of the cover 10 as shown in FIG. 16, the forming wire 30 is moved along the seam 18. While changing the shape, it is removed from between the seam allowances 17, 17 and removed from the cover 10. The seam allowance 1
7 and 17 are closed by tack pins 35, and the foamable filler 20 hardly penetrates between them, so that the molding wire 30 can be smoothly extracted. Further, if a lubricant is applied to the inner surface of the seam allowance 17 or the forming wire 30, the forming wire 30 can be extracted more smoothly. And finally, the cover 10
When the molding port 14 is closed and closed, the molding of the headrest in which the cover 10, the expandable filler 20 and the stay 40 are integrated is completed.

In the cover 10 of this embodiment, the seam allowance 17 is bent inward, and the seam 18 tends to be recessed inward due to the repulsive force caused by the bending of the seam allowance 17. Since the seam 18 corresponds to the corner edge and the bending angle of the seam allowance 17 is tight, the repulsive force of the seam allowance 17 is further increased. However, in the molding method of the present embodiment, as means for expanding the cover 10 in the molding die 50 into a predetermined shape,
Since not only the expansive force of the foamable filler 20 but also the shape restoring force of the shape memory alloy stronger than this is mainly used, the force for expanding the cover 10 is extremely large. Therefore, the portion of the seam 18 corresponding to the corner edge can be sufficiently inflated to the outside to expand the cover 10 into a regular shape.

Further, since the shape memory alloy is deformable at room temperature, it becomes possible to reverse the cover 10 together with the forming wire 30 after attaching the forming wire 30 to the outer surface of the sewn cover 10. There is. Therefore, after the cover 10 is inverted, the forming wire 3 is formed inside the cover 10.
Workability is extremely excellent as compared with the case where the mounting work of 0 is performed.

Since the forming wire 30 is held inside the seam 18 by being sandwiched between the seam allowances 17, 17, the forming wire 30 shifts to the side of the seam 18 and projects to the outside of the cover 10. There is no possibility that a highlight state will occur, and the cover 1 caused by the occurrence of the highlight state
It is possible to prevent defects of 0 shape.

After forming the headrest, the forming wire 30 is formed.
Since it is designed to be removed from the cover 10, the removed forming wire 30 can be reused, which makes it possible to reduce the cost.

<Other Embodiments> The present invention is not limited to the embodiments described above and illustrated in the drawings. For example, the following embodiments are also included in the technical scope of the present invention. In addition to the above, various modifications can be made without departing from the scope of the invention.

(1) In the above embodiment, the case where only one forming wire 30 is used has been described, but according to the present invention, it is possible to use a plurality of forming wires 30.

(2) In the above embodiment, the case where the seam 18 of the cover 10 is arranged along the corner edge portion of the headrest has been described, but in the present invention, the seam 18 corresponds to a portion other than the corner edge. It can also be applied in cases. In this case, the forming wire 30 may be routed only along the seam 18, may be routed along only the corner edge, or may be routed along both the seam 18 and the corner edge. Good.

(3) In the above embodiment, the case where the cover 10 is made by sewing a plurality of cloths has been described.
The present invention can be applied to the case where the cover is made of one sheet material and has no seam.

(4) In the above embodiment, the forming wire 30 made of a wire was used as the forming member, but in the present invention, it is also possible to use a shape memory alloy formed into a plate shape as the forming member.

(5) The present invention is not limited to the automobile headrest described in the above embodiments, but can be applied to other products.

[Brief description of drawings]

FIG. 1 is an external perspective view of a headrest to which the present invention is applied.

FIG. 2 is a development view of the fabric forming the headrest cover.

FIG. 3 is a perspective view showing a state in which the cover is sewn.

FIG. 4 is a perspective view of the sewn cover as seen from below.

FIG. 5 is a perspective view of a forming wire.

FIG. 6 is a perspective view of a tack pin.

FIG. 7 is a partially enlarged perspective view showing a means for attaching a forming wire to a cover.

FIG. 8 is a perspective view showing a state in which the cover is inverted after the forming wire is attached.

FIG. 9 is a partially enlarged cross-sectional view showing a mounting state of a forming wire.

FIG. 10 is a perspective view showing a state where the cover is set in a molding die.

FIG. 11 is a partially enlarged perspective view showing a structure for supporting hooks at both ends of a forming wire.

FIG. 12 is a plan view showing an operation of opening an injection port for a foamable filler.

FIG. 13 is a vertical cross-sectional view showing a state in which a foamable filler is filled.

FIG. 14 is a cross-sectional view showing a state in which a foamable filler is filled.

FIG. 15 is a perspective view showing a state during curing of the headrest removed from the molding die.

FIG. 16 is a perspective view showing a state where the forming wire is removed from the cover.

[Explanation of symbols]

 10 ... Cover 17 ... Seam allowance 20 ... Foamable filler 30 ... Molding wire (molding member) 50 ... Mold

Claims (2)

[Claims] 1. An easily deformable bag-shaped cover is housed in a mold, and an expandable filler is injected into the inside of the cover to be expanded and filled by a foaming action, and the expandable filler is hardened. A cover-integrated foam-molded body molding method for obtaining a cover-integrated foam-molded body in which the cover and the expandable filler are integrated, wherein the inside of the cover in the mold before the injection of the foamable filler The cover-integrated foam molding is characterized in that a molding member made of a shape memory alloy is provided which can be restored to the shape along the inner wall surface of the molding die by being heated by the foaming reaction heat of the foaming filler. Body shaping method. 2. The cover is formed by sewing and the molding member is in the shape of a wire, and the molding member can be pulled out in a state of being sandwiched between the seam allowances folded back to the inside of the cover. The method for molding a cover-integrated foam-molded article according to claim 1, which is attached.