JP7770091B2 - Manufacturing method for foam molded product and molding die - Google Patents

Description

The present invention relates to a method and mold for producing a foam-molded product in which an insert is inserted into a padding material.

Known examples of this type of foam-molded product include seat backs and seat cushions for seats installed in automobiles, etc. In these products, in order to provide good support for the occupant's body, reduce fatigue, and reduce the weight of the foam-molded product, foam-molded inserts are sometimes produced by embedding foam- molded inserts formed into a predetermined shape using foam beads or the like in a mold to form a padding material by foaming a foamable raw material in the mold. A known method for producing such foam-molded products is disclosed in Patent Document 1 (JP-A-9-70836).

The manufacturing method described in Patent Document 1 involves placing an impact absorbing pad, which is an insert product, in a molding die configured so that a middle die (core die) is inserted between a lower die and an upper die, and injecting a foamable raw material into the molding die to foam, thereby producing an automobile seat back with the impact absorbing pad insert-molded into it. In this manufacturing method, protrusions are provided on the sides of the middle die, and recesses are formed on the surface of the impact absorbing pad into which the protrusions can be press-fitted. When a worker places the impact absorbing pad in the molding die, they press the protrusions of the middle die into the recesses of the impact absorbing pad, allowing the impact absorbing pad to be detachably attached to the middle die. Pressing the protrusions of the middle die into the recesses of the impact absorbing pad ensures that the impact absorbing pad is attached to the middle die in the correct position and orientation, preventing the impact absorbing pad from shifting when the mold is subsequently closed.

Japanese Patent Application Publication No. 9-70836

However, with the manufacturing method described in Patent Document 1, depending on the size of the impact absorbing pad (the insert product) and the relative positions of the worker and the impact absorbing pad, it may be difficult for the worker to visually check the medium-sized protrusions while holding the impact absorbing pad, making it difficult to press the medium-sized protrusions into the recesses in the impact absorbing pad.

The problem that this invention aims to solve is to provide a manufacturing method and mold for foam-molded products that makes it easier for workers to set inserts into the upper mold.

In order to solve the above-mentioned problems, the invention according to claim 1 is a method for manufacturing a foam-molded product in which an insert is insert-molded into a pad material using a molding die having at least an upper die and a lower die, the molding die being formed with at least one abutment and protrusion for determining the set position of the insert at a predetermined position of the upper die, and the abutment part being formed with an abutment surface facing the protrusion, the insert being formed of a foam resin in a plate shape and having an end face that abuts against the abutment surface of the abutment part of the upper die and a through hole that fits into the protrusion, and the insert being formed with a foam resin in a plate shape and having an end face that abuts against the abutment surface of the abutment part of the upper die and a through hole that fits into the protrusion, and the insert being formed with a foam resin in a plate shape and having an end face that abuts against the abutment surface of the abutment part of the upper die and a through hole that fits into the protrusion, and the insert being formed with a foam resin in a plate shape and having an end face that abuts against the abutment surface of the abutment part of the upper die and a through hole that abuts against ... a step of butting the end face of the insert piece against the contact surface of the contact portion of the upper mold, a step of facing the back surface of the insert piece to the upper mold with the end face of the insert piece against the contact surface of the contact portion of the upper mold, a step of pressing the back surface of the insert piece against the upper mold to fit the through hole of the insert piece into the protrusion of the upper mold and set the insert piece at a predetermined set position of the upper mold, and a step of injecting a foamable raw material into the lower mold, closing the molding mold to foam-molde the pad material and insert-molding the insert piece into the pad material,
when the molding die is open, at least a part of the contact portion of the upper die is formed to be located above the protrusion,
The size of the through hole of the insert piece is formed slightly smaller than the size of the protrusion of the upper die,
The insert is set in the upper die in a state where the insert is sandwiched between the protrusion of the upper die and the contact surface of the contact portion .

In this manufacturing method, when an operator sets an insert piece in the upper mold, the operator can easily determine the rough position of the insert piece relative to the upper mold by butting the end face of the insert piece against the abutment surface of the abutment portion of the upper mold. Then, by facing the back surface of the insert piece to the upper mold while the end face of the insert piece is butted against the abutment surface of the abutment portion of the upper mold, the through hole of the insert piece can be (automatically) positioned in a position corresponding to the protrusion of the upper mold. This allows the operator to easily fit the through hole of the insert piece into the protrusion of the upper mold by pressing the back surface of the insert piece against the upper mold without visually checking the protrusion of the upper mold, and the operator can easily set the insert piece in the predetermined setting position of the upper mold.

In this case, when the molding die is open, at least a portion of the abutment portion of the upper die is formed to be positioned above the protrusion, making it easier for the worker to visually check the abutment portion of the upper die while holding the insert product.
Moreover, because the through hole of the insert is fitted into the protrusion of the upper mold, it is possible to visually confirm through the through hole that the insert has been set in the predetermined position in the upper mold. Furthermore, because the size of the through hole of the insert is formed slightly smaller than the size of the protrusion of the upper mold, the insert is set in the upper mold with the inner surface of the through hole of the insert and the protrusion of the upper mold making strong contact, making it possible to prevent the insert from shifting position or coming off the upper mold when the molding mold is closed.
Furthermore, since the insert is set in the upper mold while being sandwiched between the protrusion of the upper mold and the abutment surface of the abutment part, the insert is less likely to shift position or come off the upper mold even when the molding mold is closed or when the foamable raw material is foaming and flowing.

Furthermore, as in claim 2 , before setting the insert item in the upper mold, a back surface reinforcement material may be set in the upper mold, and then the insert item may be set in the upper mold so as to overlap at least a portion of the back surface reinforcement material. In this way, the back surface reinforcement material that covers the back surface of the foam-molded item and the insert item can be integrated into the padding material.

The molding die used in the invention of the "method for manufacturing a foam-molded product" according to claim 1 described above, as in claim 3 , has at least an upper die and a lower die, the upper die is attached to the lower die so as to be able to open and close, the upper die is formed with at least one abutment portion against which the upper end face of an insert item abuts, and a protrusion that fits into the through hole when the back surface of the insert item is pressed against the upper die with the end face abutting against the abutment portion, and the abutment portion is formed with an abutment surface that faces the protrusion , and when the molding die is in an open state, at least a portion of the abutment portion of the upper die is formed to be positioned higher than the protrusion, and the size of the protrusion of the upper die is formed slightly larger than the size of the through hole of the insert item, and the insert item is set in the upper die with the protrusion of the upper die and the abutment surface of the abutment portion.

FIG. 1 is a perspective view of an expansion molded product according to one embodiment of the present invention. FIG. 2 is a perspective view of the insert. FIG. 3 is a cross-sectional view illustrating the process of opening the mold and setting an insert in the upper mold. FIG. 4 is a cross-sectional view showing the state in which the molding die is opened and an insert is set in the upper die. FIG. 5 is a cross-sectional view showing the state in which the foamable raw material is injected into the lower mold and the molding die is closed. FIG. 6 is a plan view of the upper mold. FIG. 7 is a plan view showing the state in which the back surface reinforcement material is set in the upper mold. FIG. 8 is a plan view showing the state in which the insert is set in the upper die.

The following describes one embodiment in which the present invention is applied to a manufacturing method of cushioning material for a vehicle seat back (backrest portion).

First, the structure of the cushion material 11 for a vehicle seat back manufactured using the manufacturing method of this embodiment will be described with reference to Figure 1.

The cushion material 11 for a vehicle seat back is a foam-molded product in which an insert 13 is insert-molded into a pad material 12, which is a foam cushion material. The pad material 12 is foam-molded by injecting a liquid foamable raw material 38 (for example, a foamable polyurethane raw material made by mixing a polyol-based resin raw material and an isocyanate-based resin raw material with a blowing agent such as water) into a mold 31, which will be described later. Left and right pad side portions 14, 15 are integrally molded on both the left and right sides of the pad material 12 so that they rise up from the front, stabilizing the seated posture of the occupant.

On the other hand, the insert part 13 is formed from foam resin such as foam beads, and as shown in Figures 1 and 2, it is integrally formed with a center part 16 and left and right side parts 17, 18 rising from the left and right side parts of this center part 16. The center part 16 is embedded in the pad main part 12a of the pad material 12, and the left and right side parts 17, 18 are embedded in the left and right pad side parts 14, 15 of the pad material 12, respectively, by insert molding.

As shown in Figures 3 to 6, the insert piece 13 has an end surface 13a (the upper end surface in this embodiment) that abuts against the contact surface 33a of the contact portion 33 of the upper mold 32, which will be described later, and a fitting portion 20 that fits into the protrusion 34 of the upper mold 32, which will be described later. This fitting portion 20 may be a recess shaped to match the shape of the protrusion 34 of the upper mold 32. However, in this embodiment, the fitting portion 20 is formed as a through hole (circular in this embodiment) with a cross-sectional shape (circular in this embodiment) that matches the cross-sectional shape of the protrusion 34 of the upper mold 32 and through which the protrusion 34 can pass. The size (diameter) of the fitting portion 20 is slightly smaller than the size (diameter) of the protrusion 34 of the upper mold 32. This prevents the insert piece 13 from coming off the upper mold 32, even when the inner circumferential surface of the fitting portion 20 contacts the outer circumferential surface of the protrusion 34 to close the molding die 31 or when the foamable raw material 38 is foaming and flowing.

As shown in Figure 8, the length H from the portion of the fitting portion 20 of the insert item 13 closest to the end face 13a of the insert item 13 to said end face 13a is slightly smaller than the length h (see Figure 6) from the portion of the protrusion 34 of the upper mold 32 closest to the contact surface 33a of the contact portion 33 to said contact surface 33a. This ensures that the insert item 13 is sandwiched between the protrusion 34 and the contact portion 33 of the upper mold 32, preventing the insert item 13 from shifting position or coming off the upper mold 32 even when the molding mold 31 is closed or the foamable raw material 38 is foaming and flowing.

On the other hand, a back surface reinforcement material 21 (see Figures 7 and 8) that covers the back surface of the padding 12 is insert-molded together with the insert item 13 to integrate the three components. The back surface reinforcement material 21 is formed by sewing together a cloth-like material such as nonwoven fabric cut to a predetermined shape, and at positions on the back surface reinforcement material 21 that correspond to the abutment portion 33 and protrusion 34 of the upper mold 32 (described below), through-holes 22, 23 are formed through which the abutment portion 33 and protrusion 34 can pass, respectively. This back surface reinforcement material 21 not only reinforces the padding 12, but also serves to prevent the padding 12 and insert item 13 from coming into direct contact with the frame (not shown) to which the cushioning material 11 is attached, thereby preventing the generation of abnormal noise.

Next, the structure of the molding die 31 for molding the cushion material 11 will be described with reference to FIGS.
The molding die 31 is arranged so as to mold the front side of the cushion material 11 (the side facing the back of the person sitting) facing downward, and is composed of at least an upper die 32 and a lower die 35. The upper die 32 is attached to the lower die 35 via a hinge shaft 36 so as to be able to pivot open and close. At least one abutment portion 33 and a protrusion 34 are formed in predetermined positions on the upper die 32 for determining the setting position of the insert item 13. The abutment portion 33 and the protrusion 34 may be formed integrally with the upper die 32, or may be formed by attaching separate parts.

6, two abutting portions 33 and two protrusions 34 are formed at symmetrical positions, and by pressing the back surface of the insert piece 13 against the upper die 32 with the upper end face 13a of the insert piece 13 abutting against the abutting portions 33, the fitting portion 20 of the insert piece 13 is (automatically) fitted directly into the protrusions 34. The positional relationship between the abutting portions 33 and the protrusions 34 of the upper die 32 is formed so that at least a portion of the abutting portions 33 of the upper die 32 is located above the protrusions 34 when the molding die 31 is open, as shown in FIGS.

Next, a method for manufacturing the cushion material 11 using the molding die 31 will be described.
First, as shown in Fig. 3, with the molding die 31 open, an operator sets the back surface reinforcement material 21 on the inner surface of the upper die 32. At this time, as shown in Fig. 7, holes 22 and 23 are formed in the back surface reinforcement material 21 so as to avoid the contact portion 33 and protrusion 34 of the upper die 32.

After this, as shown in Figure 3, the worker holds the insert piece 13 and places the upper end surface 13a of the insert piece 13 against the contact surface 33a of the contact portion 33 of the upper die 32. This roughly determines the position of the insert piece 13 relative to the upper die 32. In this embodiment, when the molding die 31 is open, at least a portion of the contact portion 33 of the upper die 32 is formed to be positioned above the protrusion 34, so the worker can easily visually check the contact portion 33 of the upper die 32 while holding the insert piece 13.

Then, with the upper end surface 13a of the insert piece 13 abutting against the abutment surface 33a of the abutment portion 33 of the upper die 32, the back surface of the insert piece 13 is brought into opposition to the upper die 32. As a result, the mating portion 20 of the insert piece 13 is (automatically) positioned in a position corresponding to the protrusion 34 of the upper die 32, and the insert piece 13 overlaps at least a portion of the back surface reinforcement material 21. In this state, as shown in FIG. 4, by pressing the back surface of the insert piece 13 against the upper die 32, the mating portion 20 of the insert piece 13 is fitted into the protrusion 34 of the upper die 32, and the insert piece 13 is set in a predetermined position in the upper die 32. This allows the operator to easily fit the mating portion 20 of the insert piece 13 into the protrusion 34 of the upper die 32 by pressing the back surface of the insert piece 13 against the upper die 32 without visually checking the protrusion 34 of the upper die 32.

In this embodiment, the fitting portion 20 of the insert item 13 is a through-hole, so that it is possible to visually confirm that the insert item 13 has been set in the upper mold 32 by fitting the fitting portion 20 of the insert item 13 into the protrusion 34 of the upper mold 32.

Furthermore, in this embodiment, the size of the fitting portion 20 of the insert piece 13 is formed slightly smaller than the size of the protrusion 34 of the upper die 32, so the insert piece 13 is set in the upper die 32 with the inner surface of the fitting portion 20 of the insert piece 13 firmly abutting against the outer surface of the protrusion 34 of the upper die 32. This makes it difficult for the insert piece 13 to come off the upper die 32 when the molding die 31 is closed.

Furthermore, in this embodiment, the length H from the portion of the fitting portion 20 of the insert piece 13 closest to the end face 13a of the insert piece 13 to said end face 13a is slightly smaller than the length h from the portion of the protrusion 34 of the upper mold 32 closest to the contact surface 33a of the contact portion 33 to the corresponding contact surface 33a. Therefore, the insert piece 13 is set in the upper mold 32 in a state where it is sandwiched between the protrusion 34 of the upper mold 32 and the contact surface 33a of the contact portion 33. This makes it difficult for the insert piece 13 to come off the upper mold 32 when the molding mold 31 is closed.

After the insert item 13 is set, a foamable raw material 38, such as a foamable polyurethane raw material, is injected into the lower mold 35. As shown in Figure 5, the mold 31 is closed and the foamable raw material 38 is foamed. The foamed foamable raw material 38 is then filled into the cavity of the mold 31 to form the padding material 12, and the cushioning material 11 is manufactured by integrating the insert item 13 and the back surface reinforcement material 21 on the back surface of the padding material 12 by insert molding.

In this embodiment, the upper end face 13a of the insert piece 13 abuts against the abutment surface 33a of the abutment portion 33 of the upper die 32. This has the advantage that even if the insert piece 13 is large, the worker can easily hold the insert piece 13 and abut its upper end face 13a against the abutment surface 33a of the abutment portion 33 of the upper die 32. However, the present invention may also be configured so that the lower end face, left end face, or right end face of the insert piece 13 abuts against the abutment surface of the abutment portion formed in a predetermined position on the upper die 32.

The present invention may also be applied to a molding die in which the upper die includes a core die. In this case, the core die may be configured to have at least one contact portion and one protrusion. The number of contact portions and protrusions is not limited to two each, and may be one or three or more each.

In addition, in this embodiment, the insert 13 is embedded in the padding material 12 and the back surface of the insert 13 is covered with the back surface reinforcement material 21, but the insert 13 may be embedded in the padding material 12 with part of it exposed.

In addition, the scope of application of the present invention is not limited to methods for manufacturing cushioning materials for vehicle seat backs, but can be widely applied to methods for manufacturing foam-molded products in which an insert is molded into a padding material using a molding die having at least an upper die and a lower die.

11... Vehicle seat back cushion material (foam molded product), 12... Pad material, 12a... Pad main portion, 13... Insert part, 13a... End surface, 14, 15... Pad side portion, 16... Center portion, 17, 18... Side portions, 20... Fitting portion, 21... Back surface reinforcement material, 22, 23... Hole, 31... Mold, 32... Upper mold, 33... Contact portion, 33a... Contact surface, 34... Protrusion, 35... Lower mold, 38... Foamable raw material

Claims (3)

A method for manufacturing a foam-molded product in which an insert is insert-molded into a pad material using a molding die having at least an upper die and a lower die,
The molding die is formed with at least one contact portion and a protrusion at a predetermined position of the upper die for determining the setting position of the insert, and the contact portion has a contact surface facing the protrusion,
The insert is formed into a plate shape from foamed resin and has an end surface that contacts the contact surface of the contact portion of the upper mold and a through hole that fits into the protrusion,
a step of abutting the end surface of the insert piece against the contact surface of the contact portion of the upper mold while the molding die is open;
a step of placing a back surface of the insert piece against the upper die in a state where the end surface of the insert piece is abutted against the abutment surface of the abutment portion of the upper die;
a step of pressing the back surface of the insert against the upper die to fit the through hole of the insert into the protrusion of the upper die, thereby setting the insert at a predetermined setting position of the upper die;
a step of injecting a foamable raw material into the lower mold, closing the molding die, and foam-molding the pad material to insert-molde the insert into the pad material,
when the molding die is open, at least a part of the contact portion of the upper die is formed to be located above the protrusion,
The size of the through hole of the insert piece is formed slightly smaller than the size of the protrusion of the upper die,
A method for manufacturing a foam-molded product, characterized in that the insert is set in the upper mold in a state where the insert is sandwiched between the protrusion of the upper mold and the abutment surface of the abutment portion. The method for manufacturing a foam-molded product described in claim 1, characterized in that before setting the insert item in the upper mold, a back surface reinforcement material is set in the upper mold, and then the insert item is set in the upper mold so as to overlap at least a portion of the back surface reinforcement material. A mold for producing a foam-molded product in which an insert member having at least one end face and a through hole and formed into a plate shape from foam resin is insert-molded into a pad material that is a foam cushion material,
It has at least an upper mold and a lower mold,
The upper mold is attached to the lower mold so as to be pivotable to open and close,
the upper die is formed with at least one abutment portion with which the upper end face of the insert abuts, and a protrusion portion that fits into the through hole when the back surface of the insert is pressed against the upper die with the end face abutting against the abutment portion, and the abutment portion is formed with an abutment surface that faces the protrusion ,
when the molding die is open, at least a part of the contact portion of the upper die is formed to be located above the protrusion,
The size of the protrusion of the upper die is formed slightly larger than the size of the through hole of the insert piece,
A molding die characterized in that the insert is set in the upper die in a state where the insert is sandwiched between the protrusion of the upper die and the abutment surface of the abutment portion.