JP7603370B2 - Seat pad, its manufacturing method, and mold - Google Patents

Description

This invention relates to a seat pad for use in seats of vehicles, etc., a method for manufacturing the seat pad, and a molding die.

A vehicle seat is attached in a taut state by holding a seat cover with a wire attached to the bottom of a groove formed on one side of the seat pad, and pulling part of the seat cover into the groove (see, for example, Patent Document 1). Such a seat pad is obtained by insert molding in which a wire is attached to the top of a convex part formed in the lower part of a molding die, and the foam raw material is foamed and cured with the wire positioned at a position corresponding to the bottom of the groove of the seat pad.

JP 2011-45424 A

When a seat pad is formed in a molding die, the foam raw material is supplied to each of the areas partitioned by the convex portion of the lower die. When the foam raw material distributed and supplied to each area expands due to foaming, the foams join together at the top of the convex portion. Due to stress when the foam raw material joins together, a skin layer forms on the bottom of the groove in the resulting seat pad, and the presence of the skin layer weakens the strength of the bottom of the groove.

The present invention has been proposed in view of the above problems associated with the conventional technology, and aims to provide a seat pad with excellent groove strength, a method for manufacturing said seat pad, and a mold for obtaining said seat pad.

In order to overcome the above problems and achieve the intended object, the seat pad according to the present invention comprises:
A seat pad constructed from molded foam,
A groove portion formed so as to be recessed from one surface of the seat pad;
a plurality of recesses formed in a bottom surface of the groove and smaller than a width of the groove, the recesses being spaced apart in an extension direction of the groove;
The present invention relates to a method for manufacturing a semiconductor device, comprising the steps of: forming a skin layer on a surface of the recess;

In order to overcome the above problems and achieve the intended object, the manufacturing method of the seat pad according to the present invention comprises the steps of:
A method for manufacturing a seat pad, comprising forming a groove portion recessed from one surface of the seat pad when the seat pad is formed from a foam raw material in a mold, the method comprising the steps of:
supplying the foam raw material to both sides of a convex portion that forms the groove portion in a lower portion of the molding die;
The gist of the invention is that the seat pad is molded while forming a recess recessed from the bottom surface of the groove portion by a plurality of protrusions that rise from the top of the convex portion and are spaced apart from one another.

In order to overcome the above problems and achieve the intended object, the molding die according to the present invention comprises:
A mold for molding a seat pad made of a foam in a cavity defined by a lower mold and an upper mold,
The lower mold is
A convex portion that forms a groove portion that is recessed from one surface of the seat pad;
The present invention is characterized in that it comprises a plurality of protrusions that are provided rising from the top of the convex portion and are spaced apart from each other in the extending direction of the convex portion.

According to the seat pad of the present invention, the strength of the groove portion can be improved.
According to the method for manufacturing a seat pad of the present invention, it is possible to obtain a seat pad having improved strength in the groove portion.
According to the molding die of the present invention, a seat pad having grooves with improved strength can be obtained.

1 is a perspective view showing a seat using a seat pad according to an embodiment of the present invention. 1 is a front view showing a seat pad according to an embodiment of the present invention, showing one surface side of the seat pad. 3 is a cross-sectional view taken along line AA in FIG. 2. 3 is a cross-sectional view taken along line BB in FIG. 2. 1A to 1C are explanatory diagrams showing a manufacturing process of the seat pad of the embodiment. FIG. 2 is a plan view showing a lower die of a molding die according to an embodiment of the present invention. 7 is a cross-sectional view taken along line CC of FIG. 6. FIG. 4 is a perspective view showing a convex portion of the embodiment.

Next, the seat pad, the manufacturing method for the seat pad, and the molding die according to the present invention will be described below with reference to the attached drawings, showing preferred embodiments.

As shown in Figure 1, a vehicle seat 10 is basically composed of a seat 12 that supports the lower body of an occupant, a backrest 14 that is tiltably installed at the rear of the seat 12 and supports the upper body of the occupant, and a headrest 16 that is installed on the upper part of the backrest 14 and supports the head of the occupant. The seat 12 and backrest 14 are composed of a seat pad 20 that is mainly made of soft polyurethane foam and has cushioning properties as a whole, and a seat cover 18 made of fabric, synthetic leather, genuine leather, or the like that is pasted over the entire seat pad 20. The seat 12 and backrest 14 are similar in basic structure and are also manufactured in the same way, so the seat pad 20 that forms the backrest 14 and headrest 16 will be described below. In addition, in the explanation of the seat pad 20, up, down, front, back, left and right are indicated based on the installation state in the vehicle, and in the seat pad 20 constituting the backrest portion 14, the side of the support surface of the occupant seated on the seat 10 is the front, and the opposite side is the rear. Also, the head side of the occupant seated on the seat 10 is the top, the buttocks side of the occupant is the bottom, the right arm side is the right, and the left arm side is the left.

As shown in Figs. 2 and 3, the seat pad 20 has a groove 22 that opens to the front (one surface) facing the occupant. In the embodiment, the seat pad 20 has one groove 22 extending in the left-right direction (see Fig. 2). As shown in Figs. 2 and 4, the seat pad 20 has a recess 24 that is recessed from the bottom surface of the groove 22 in the depth direction of the groove 22 (to the rear surface in the embodiment). In the groove 22, a plurality of recesses 24 are arranged apart from each other in the extension direction of the groove 22 (left-right direction in the embodiment). Each recess 24 is formed smaller than the width of the groove 22. The recess 24 is arranged apart from the groove wall that divides the groove 22, so that the groove wall and the side of the recess 24 are not linearly connected. In addition, the recess 24 is formed smaller than the dimension in the extension direction of the groove 22. The opening shape of the recess 24 may be a circle (embodiment) or a polygon such as a square or a triangle. The recess 24 may be formed with the same opening dimensions from the opening facing the bottom surface of the groove 22 to the bottom (example), or may have a tapered shape in which the opening area becomes smaller as it moves from the opening to the bottom, or may have some other shape.

In the following description, the direction corresponding to the opposing groove walls of the groove portion 22 is referred to as the width direction, and the direction corresponding to the extension direction of the groove portion 22 is referred to as the lateral direction. Additionally, the direction corresponding to the depth direction of the groove portion 22 in the seat pad 20 is the front-rear direction.

The width dimension of the recess 24 may be set in the range of, for example, 3 mm to 6 mm, provided that it is smaller than the width dimension of the groove 22. The width dimension and the horizontal dimension of the recess 24 may be the same, or the horizontal dimension may be larger or smaller than the width dimension, but it is preferable not to increase the horizontal dimension, since this does not impair the strength of the bottom surface of the groove 22. The depth of the recess 24 may be set in the range of, for example, 5 mm to 20 mm. The interval between the multiple recesses 24 in the groove 22 may be set in the range of, for example, 5 mm to 40 mm. The multiple recesses 24 may have different shapes and dimensions, but in the embodiment, all the multiple recesses 24 are formed with the same shape and size. The recess 24 has a skin layer 24a on the surface. In the seat pad 20, there is more skin layer 24a per unit area on the surface (wall surface, bottom surface, etc.) of the recess 24 than on the bottom surface of the groove 22.

The seat pad 20 has retainers such as wires or clips (not shown) embedded in the foam in correspondence with the bottom of the grooves 22. The seat pad 20 can be attached to the seat cover 18 with the seat cover 18 in a smoothed (tensioned) state by attaching a mounting fixture attached to the seat cover 18 to the retainer and pulling the seat cover 18 into the inside of the grooves 22.

Next, the mold 40 for molding the seat pad 20 will be described. As shown in FIG. 5, the mold 40 is composed of a lower mold 42 and an upper mold 44 that is disposed above the lower mold 42 when the mold is closed. The mold 40 can be changed between a closed state (see FIG. 5(b)) in which a cavity 46 is formed between the lower mold 42 and the upper mold 44 and a mold open state (see FIG. 5(a)) in which the inside of the mold 40 can be accessed by rotating the upper mold 44 about a rotation axis 48. The mold 40 is configured to mold the front surface (one surface) of the seat pad 20 in the cavity 46 with the front surface facing downward. The mold 40 mainly molds the front and side surfaces of the seat pad 20 with the lower mold 42, and molds the rear surface of the seat pad 20 with the upper mold 44.

5 and 6, the lower mold 42 is formed to protrude from the lower mold surface (mold surface) 42a that defines the front surface (one surface) of the seat pad 20, and has a convex portion 50 that defines the groove portion 22 of the seat pad 20. The convex portion 50 is configured so that a holder can be attached to the top. The lower mold 42 is provided to rise from the top of the convex portion 50 and has a plurality of protrusions 52 that are arranged apart from each other in the extension direction of the convex portion 50. Each protrusion 52 is formed smaller than the width of the convex portion 50. In addition, the protrusion 52 is formed smaller than the lateral dimension of the convex portion 50. The shape of the protrusion 52 may be cylindrical (embodiment) or polygonal prism such as a square prism or a triangular prism. In addition, the protrusion 52 may be formed with the same cross-sectional dimensions from the base to the tip (embodiment), may be a cone shape that becomes thinner from the base to the tip, or may have other shapes. When using a clip as the holder, clip attachment parts can be provided between the projections 52 that rise from the convex portion 50, and the clip can be attached to the clip attachment parts.

The width dimension of the protrusion 52 may be set in the range of, for example, 3 mm to 6 mm, provided that it is smaller than the width dimension of the convex portion 50. The width dimension and the horizontal dimension of the protrusion 52 may be the same, or the horizontal dimension may be larger or smaller than the width dimension, but it is preferable not to increase the horizontal dimension, as this does not impair the strength of the bottom surface of the resulting groove portion 22. The height of the protrusion 52 may be set in the range of, for example, 5 mm to 20 mm. The interval between the multiple protrusions 52 in the convex portion 50 may be set in the range of, for example, 5 mm to 40 mm. The multiple protrusions 52 may have different shapes and dimensions, but in the embodiment, the multiple protrusions 52 are all formed to have the same shape and size.

The protrusions 52 are made of a material with a lower thermal conductivity than the convex portion 50 (lower mold 42). For example, if the convex portion 50 (lower mold 42) is made of aluminum material (236 w/m·k) which has a relatively high thermal conductivity, the protrusions 52 may be made of iron material (83.5 w/m·k) or stainless steel material (20.9 w/m·k) which has a lower thermal conductivity than aluminum material.

Next, a method for manufacturing the seat pad 20 using the mold 40 provided with the protrusions 52 described above will be described. The mold 40 is in a state where it has been warmed to a certain extent by heating during the previous molding process of the seat pad 20, or in a state where it has been warmed by separate heating. As described above, the protrusions 52 have a lower thermal conductivity than the convex mold portion 50, so the protrusions 52 retain heat more easily and are less likely to cool down than the convex mold portion 50. Therefore, the temperature of the protrusions 52 is higher than that of the convex mold portion 50 when the foam raw material H that will become the seat pad 20 is supplied to the mold 40. In this way, the temperature of the protrusions 52 is set to be higher than that of the convex mold portion 50.

First, a holder such as a clip is attached to a location other than the protrusion 52 provided on the top of the convex portion 50. The foam raw material H is supplied to the lower mold surface 42a of the lower mold 42, the molding die 40 is closed (see FIG. 5(b)), and heated to a predetermined temperature by a heating means such as a heating furnace, and the foam raw material H is foamed and hardened in the cavity 46 to form the seat pad 20. The foam raw material H is supplied to each of the areas of the lower mold surface 42a separated by the convex portion 50. In this embodiment, the foam raw material H is supplied to the area on the rotating shaft 48 side (the lower side of the seat pad 20) and the area on the opposite side (the upper side of the seat pad 20) across the convex portion 50.

In the molding die 40, the seat pad 20 is molded while forming recesses 24 recessed from the bottom surface of the groove portion 22 by a number of protrusions 52 that rise from the top of the convex portion 50 and are spaced apart from one another. In the embodiment, the protrusions 52 are all formed to have the same shape and size, and the recesses 24 resulting from the protrusions 52 are also all formed to have the same shape and size.

As shown in FIG. 7, the foam raw material H is distributed and supplied to both sides of the convex portion 50 in the lower mold 42 in the width direction. The foam raw materials H, H supplied sandwiching the convex portion 50 expand by foaming from the lower side (lower mold surface 42a side) to the upper side (upper mold 44 side) and join at the top of the convex portion 50. Since the foam raw material H generates heat as it foams, the foaming heat tends to accumulate in the protrusion 52, and the temperature of the protrusion 52 becomes higher than that of the convex portion 50. In addition, when the foam raw materials H, H supplied sandwiching the convex portion 50 join near the top, the foaming pressure is higher around the protrusion 52 than that of the convex portion 50, and the cells on the foam surface are easily crushed. As a result, the temperature and foaming pressure around the protrusion 52 are higher than those of the convex portion 50, making it easier to form the skin layer 24a. In comparison, it is difficult for a skin layer to form on the bottom surface of the groove portion 22, and it is possible to suppress the formation of a skin layer on the bottom surface of the groove portion 22.

As described above, by controlling the position of the skin layer 24a by the protrusions 52, it is possible to suppress the formation of a skin layer on the bottom surface of the groove portion 22 of the obtained seat pad 20. In the seat pad 20 obtained in the embodiment, the formation of a skin layer on the bottom surface of the groove portion 22 is suppressed, so that it is possible to avoid a decrease in the strength of the bottom of the groove portion 22 due to this skin layer. Therefore, even if the convex mold portion 50 interferes with the groove portion 22 when the mold 40 is opened or the seat pad 20 is demolded, the groove portion 22 is less likely to be damaged. In other words, since the groove portion 22 of the obtained seat pad 20 has excellent strength, it is possible to apply force to the groove portion 22, and it is easy to open the mold 40 and demold the seat pad 20, and the seat pad 20 can be efficiently manufactured. And, when the seat cover 18 is attached to the holder via the mounting tool, the obtained seat pad 20 can properly hold the seat cover 18 by the holder embedded in the bottom of the groove portion 22, which has excellent strength.

The seat pad 20 has a discontinuous configuration in which multiple recesses 24 are arranged at a distance from each other at the bottom of the groove 22, so that the groove 22 can be prevented from tearing from the recesses 24. For example, if the recesses are continuously formed across the lateral direction of the groove 22, the groove 22 will be prone to tearing from the continuous recesses, which is not preferable.

(Example of change)
The configuration is not limited to the above, and may be modified as follows, for example.

(1) The size and shape of the protrusions are not limited to those in the examples. Similarly, the size and shape of the recesses are not limited to those in the examples. In the examples, the protrusions and the recesses derived from the protrusions all have the same shape, but some or all of them may be formed to have different sizes and shapes.
(2) In the embodiment, the groove in which the retainer is embedded and the convex portion which forms the groove are described, but the groove in which the retainer is not embedded and the convex portion which forms the groove may be used. Since the formation of the skin layer in the groove is suppressed, the seat cover can be appropriately bonded to the bottom of the groove with an adhesive.

20 seat pad, 22 groove portion, 24 recess portion, 24a skin layer, 40 mold,
42 Lower mold, 44 Upper mold, 46 Cavity, 50 Convex portion, 52 Protrusion, H Foam raw material

Claims (4)

A seat pad made of a foam molded product,
A groove portion formed so as to be recessed from one surface of the seat pad;
a plurality of recesses each formed in a bottom surface of the groove and smaller than a width of the groove, the recesses being spaced apart in an extending direction of the groove;
a retainer embedded in the foam body in correspondence with the bottom of the groove;
A seat pad characterized in that a skin layer is formed on the surface of the recess. A method for manufacturing a seat pad, comprising forming a groove portion recessed from one surface of the seat pad when the seat pad is formed from a foam raw material in a mold, the method comprising the steps of:
supplying the foam raw material to both sides of a convex portion that forms the groove portion in a lower portion of the molding die;
A method for manufacturing a seat pad, characterized in that the seat pad is molded while forming a recess that is recessed from the bottom surface of the groove portion using a plurality of protrusions that rise from the top of the convex portion, are arranged apart from each other, and have a lower thermal conductivity than the convex portion. A method for manufacturing a seat pad, comprising forming a groove portion recessed from one surface of the seat pad when the seat pad is formed from a foam raw material in a mold, the method comprising the steps of:
supplying the foam raw material to both sides of a convex portion that forms the groove portion in a lower portion of the molding die;
The seat pad is molded while forming a recess recessed from the bottom surface of the groove portion by a plurality of protrusions that are arranged apart from each other and rise from the top of the convex mold portion and have a higher temperature than the convex mold portion when the foam raw material is supplied.
A method for manufacturing a seat pad comprising the steps of : A mold for molding a seat pad made of a foam in a cavity defined by a lower mold and an upper mold,
The lower mold is
A convex portion that forms a groove portion that is recessed from one surface of the seat pad;
a plurality of protrusions provided so as to rise from a top of the convex portion and spaced apart from one another in an extending direction of the convex portion;
The protrusion is made of a material having a lower thermal conductivity than the convex portion.
A molding die characterized by :

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