Seat pad and method for manufacturing the same

Abstract

To provide a seat pad that improves workability of wiring work and also suppress the costs required for the working work, and a method of manufacturing the seat pad that easily obtains the seat pad.SOLUTION: A seat pad 1 includes a surface layer part 1a formed of foamed polyurethane 11. At the surface layer part 1a, a wiring groove 2 is formed which has a wire harness 3 formed. The wiring groove 2 has a groove width W narrower than a diameter φ3 of the harness 3 and a groove depth D deeper than the diameter φ3 of the harness 3. A method of manufacturing the seat pad uses, as a molding tool, a molding tool which has a groove forming projection part for shaping the wiring groove 2 and also has a hole part formed on a side face of the groove forming projection part. A foamed polyurethane material is supplied into the molding tool, and when a molding is taken out of the molding tool, a molding part formed at the hole part of the groove forming projection part is forcibly drawn.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a seat pad and a method for manufacturing a seat pad. [Background technology]

[0002] 2. Description of the Related Art Some conventional seat pads are formed with a wiring groove (guide groove) for routing a wire harness (cable harness) (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-158096 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional seat pad, after the wire harness is routed along the guide groove, the wire harness needs to be fixed with tape, etc. Therefore, the conventional seat pad has room for improvement in terms of ease of wiring work and reduction of costs required for wiring work.

[0005] An object of the present invention is to provide a seat pad that improves the workability of wiring work while reducing the costs required for the wiring work, and a manufacturing method for the seat pad for easily obtaining the seat pad. [Means for solving the problem]

[0006] The seat pad according to the present invention includes a surface layer made of polyurethane foam, and a wiring groove in which a wire harness is wired is formed in the surface layer, and the wiring groove has a groove width narrower than the diameter of the wire harness and a groove depth deeper than the diameter of the wire harness. The seat pad according to the present invention improves the workability of wiring work and reduces the cost required for the wiring work.

[0007] In the seat pad according to the present invention, it is preferable that a protrusion protruding inward in a groove width direction is formed on a side surface of the wiring groove. In this case, the wire harness can be fixed more firmly.

[0008] In the seat pad according to the present invention, the groove width is preferably a width that can be molded using a molding die, resulting in a seat pad that can be manufactured at low cost.

[0009] In the seat pad according to the present invention, the groove depth is preferably three times or more the diameter of the wire harness, so that the wiring can be fixed more firmly.

[0010] The seat pad according to the present invention may further include a bead method foam disposed on the inside of the surface layer, resulting in a seat pad having wiring grooves with excellent durability.

[0011] The method for manufacturing a seat pad according to the present invention uses at least a mold and a polyurethane foam material to obtain a seat pad including a surface layer portion made of polyurethane foam and a wiring groove formed in the surface layer portion, the surface layer portion having a protrusion protruding inward in the groove width direction, the method includes a mold having a groove forming protrusion portion for forming the wiring groove and a hole portion formed in the side of the groove forming protrusion portion, a polyurethane foam material supplying step for supplying the polyurethane foam material into the mold, and a force removal step for forcefully removing the molded portion formed in the hole portion from the hole portion of the groove forming protrusion portion when removing the molded product from the mold. The method for manufacturing a seat pad according to the present invention makes it possible to easily obtain a seat pad that improves the workability of wiring work and reduces the cost required for the wiring work. Effect of the Invention

[0012] According to the present invention, it is possible to provide a seat pad that improves the workability of wiring work and reduces the costs required for the wiring work, and a manufacturing method for the seat pad for easily obtaining the seat pad. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a plan view showing a schematic view of a seat pad according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a bottom view showing the seat pad of FIG. 1. [Diagram 3] 2 is a cross-sectional view showing the seat pad of FIG. 1 along the line XX. [Figure 4] 3 is a cross-sectional view of FIG. 2 taken along the line YY. [Diagram 5] 3 is a cross-sectional view taken along the line YY in FIG. 2, showing a state in which a wire harness is embedded in a wiring groove formed in the seat pad in FIG. 1. [Figure 6] FIG. 3 is a cross-sectional view showing another example of a wiring groove formed in a seat pad along the YY cross section of FIG. 2, in which a wire harness is embedded. [Figure 7] 1A to 1C are diagrams for illustrating a schematic diagram of a method for manufacturing a seat pad according to an embodiment of the present invention. [Figure 8] FIG. 11 is another diagram for illustrating the manufacturing method of the seat pad according to the embodiment of the present invention. [Figure 9] FIG. 11 is yet another diagram for illustrating the manufacturing method of the seat pad according to an embodiment of the present invention. [Figure 10] 1 is a cross-sectional perspective view showing a main portion of a groove-forming protrusion formed in a mold used in a method for manufacturing a seat pad according to an embodiment of the present invention; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, a seat pad and a method for manufacturing a seat pad according to an embodiment of the present invention will be described with reference to the drawings.

[0015] (Seat pad) A seat pad 1 according to one embodiment of the present invention is a vehicle seat pad used in a vehicle seat (a seat for an automobile). In the following description, "upper", "lower", "left", "right", "front" and "rear" refer to directions as seen by a person seated in the seat. In the following description, the "left-right direction" is also referred to as the "width direction". In this embodiment, the "lower surface" and the "bottom surface" are synonymous. In this embodiment, the "rear surface" and the "back surface" are also synonymous.

[0016] Fig. 1 is a plan view showing the seat pad 1 from above. Fig. 2 is a bottom view showing the seat pad 1 from below. Fig. 3 is a cross-sectional view showing the seat pad 1 in the XX section of Fig. 1. Fig. 4 is a YY cross-sectional view of Fig. 2. Furthermore, Fig. 5 is a cross-sectional view showing the harness 3 embedded in the wiring groove 2 formed in the seat pad 1 in the YY section of Fig. 2.

[0017] The seat pad 1 is a seat pad including a surface layer 1a made of polyurethane foam 11. In this embodiment, the seat pad 1 is covered with the polyurethane foam 11. Referring to FIG. 2, the surface layer 1a is formed with a wiring groove 2 in which a wire harness (hereinafter also referred to as "harness") 3 is wired. In this embodiment, the wiring groove 2 is formed in the surface layer 1a on the lower side of the seat pad 1. The wiring groove 2 leads to a recessed portion 1D in which a heater or the like is installed, for example. Referring to FIG. 4, the wiring groove 2 has a groove width W and a groove depth D. The groove width W is narrower than a diameter φ3 of the harness 3 as shown in FIG. 5. The groove depth D is deeper than a diameter φ3 of the harness 3 as shown in FIG. 5.

[0018] FIG. 5 shows a state in which the harness 3 is embedded in the wiring groove 2. According to the seat pad 1, the harness 3 can be embedded in the wiring groove 2 as shown in FIG. 5 by pushing the harness 3 into the wiring groove 2 from the opening 2a of the wiring groove 2. As a result, the harness 3 is protected by the polyurethane foam 11 forming the wiring groove 2. Also, the harness 3 embedded in the wiring groove 2 is fixed in a compressed state by the polyurethane foam 11 forming the wiring groove 2. As a result, the harness 3 is firmly fixed in the wiring groove 2. Therefore, according to the seat pad 1, the harness 3 can be wired along the wiring groove 2 by a simple operation of pushing the harness 3 into the wiring groove 2. Also, the wiring operation using the seat pad 1 can be performed by simply pushing the harness 3 into the wiring groove 2 without using a separate fixing means such as a tape.

[0019] Therefore, the seat pad 1 improves the efficiency of the wiring work and reduces the cost required for the wiring work.

[0020] In this embodiment, the seat pad 1 is a seat pad including a cushion pad (a pad located under the buttocks of a seated person). With reference to Figs. 1 to 3, in this embodiment, the seat pad 1 is a cushion pad. With reference to Fig. 3, in this embodiment, the seat pad 1 includes a polyurethane foam 11 and a bead-method foam 12 embedded in the polyurethane foam 11. The lower surface 1f2 of the seat pad 1 is formed by the lower surface 11f2 of the polyurethane foam 11. Here, the lower surface 1f2 of the seat pad 1 is, for example, a surface obtained by connecting the lowest points at any position in the front-rear and left-right directions of the seat pad 1 with reference to the plan view of Fig. 2. With reference to Fig. 3, the entire lower surface 12f2 of the bead-method foam 12 is located above the lower surface 11f2 of the polyurethane foam 11.

[0021] More specifically, in this embodiment, the seat pad 1 is a seat pad for a rear seat.

[0022] For example, referring to FIG. 1, in this embodiment, the seat pad 1 is a cushion pad for a rear seat in which two seats, one on the left and one on the right, are integrally formed. In this embodiment, the seat pad 1 has two main pad parts 211. The main pad part 211 is configured to support the buttocks and thighs of a seated person from below. In addition, in this embodiment, the seat pad 1 has a pair of side pad parts 212 located on the left or right side of the two main pad parts 211, raised above the main pad parts 211, and configured to support the seated person from both the left and right sides. Furthermore, in this embodiment, the seat pad 1 has a center pad part 213 arranged between the two main pad parts 211. In addition, in this embodiment, the seat pad 1 has an attachment part 214 for attaching the seat pad 1 to a vehicle. Furthermore, in this embodiment, the main pad portion 211 includes a lower-thigh portion 211a configured to support the thighs of a seated person from below, and a lower-buttock portion 211b located behind the lower-thigh portion 211a and configured to support the buttocks of the seated person from below. In this embodiment, the recessed portion 1D is located below the lower-buttock portion 211b.

[0023] In this embodiment, the surface layer 1a of the seat pad 1 is formed of a polyurethane foam 11. The polyurethane foam 11 has elasticity. An example of the polyurethane foam is soft polyurethane foam. In the seat pad 1, the bead method foam 12 may be a foam that is harder and more elastic than the polyurethane foam. An example of the bead method foam 12 is an olefin resin, specifically, a bead method expanded polypropylene (EPP) or a bead method expanded polystyrene (EPS). Here, the "bead method foam" is a foam obtained by a so-called bead method. The bead method foam is obtained by fully expanding pre-expanded foam beads in a mold.

[0024] As shown in FIG. 4, in this embodiment, the wiring groove 2 is a wiring groove having a U-shaped cross section when viewed in a vertical cross section. That is, as shown in FIG. 4, the wiring groove 2 is a wiring groove in which a gap is formed in the groove width direction. The groove width W of the wiring groove 2 is the width between the side surfaces 2s of the wiring groove 2. In this embodiment, the groove width W of the wiring groove 2 is equal in the groove depth direction (vertical direction) as shown in FIG. 4. A specific example of the groove width W can be 3 mm when the diameter φ3 of the harness 3 is 4 mm. Another specific example of the groove width W can be 5 mm when the diameter φ3 of the harness 3 is 10 mm.

[0025] In this embodiment, the groove width W is preferably a groove width that can be molded using a mold. In this case, the wiring groove 2 can be molded together with the seat pad 1 by using a mold. Therefore, in this case, the seat pad can be manufactured at low cost. Such a groove width W may be, for example, 2 mm or more.

[0026] In this embodiment, the groove depth D is preferably three times or more the diameter φ3 of the harness 3. In this case, even when the harness 3 is embedded in the center of the wiring groove 2 in the groove depth direction, the distance to the opening 2a of the wiring groove 2 formed on the surface (surface of the surface layer 1a) of the polyurethane foam 11 is ensured to be equal to or more than the diameter φ3 of the harness 3. In this way, in this embodiment, a large distance to the opening 2a of the wiring groove 2 when the harness 3 is embedded can be ensured. Therefore, in this case, the harness 3 can be fixed more firmly. As a specific example, when the diameter φ3 of the harness 3 is 4 mm or 10 mm, the groove depth D can be set to 35 mm≦D≦50 mm.

[0027] In this embodiment, as shown in FIG. 3, the seat pad 1 has a bead method foam 12 disposed on the inside of the surface layer 1a.

[0028] The polyurethane foam 11 ensures both seating stability and seating comfort. The bead method foam 12 is harder than the polyurethane foam 11 and ensures seating stability. Therefore, in this embodiment, seating comfort is ensured and seating stability is improved.

[0029] However, the bead method foam 12 has lower heat resistance than the polyurethane foam 11. Therefore, when the wiring groove 2 is formed in the surface layer 1a of the seat pad 1 (particularly, the lower surface 1f2 of the seat pad 1), the wiring groove 2 is directly affected by heat.

[0030] In this embodiment, the bead method foam 12 is disposed inside the polyurethane foam 11, and the wiring groove 2 is formed in the polyurethane foam 11. In this case, the influence of heat that may occur in the wiring groove 2 can be suppressed compared to when the wiring groove 2 is formed in the bead method foam 12. Therefore, in this case, the seat pad has a wiring groove 2 with excellent durability. For example, in the case of an electric vehicle, a heat source device that generates high heat, such as a battery or a motor, may be disposed under the rear seat. Therefore, the seat pad 1 is particularly effective when used as a seat pad for a rear seat, as in this embodiment.

[0031] In the seat pad 1, the polyurethane foam 11 is preferably made of soft polyurethane foam, and the bead-method foam 12 is preferably made of bead-method polypropylene foam or bead-method polystyrene foam. In this case, the use of commonly used polyurethane foam and bead-method foaming materials results in a cost-effective seat pad. In particular, when the bead-method foam 12 is made of bead-method polystyrene foam, the bead-method polystyrene foam has lower thermal durability than other bead-method foams. For this reason, when the bead-method foam 12 is made of bead-method polystyrene foam, the application of the present invention is effective in improving thermal durability. However, according to the present invention, the seat pad 1 can be made of only the polyurethane foam 11.

[0032] Fig. 6 is a cross-sectional view showing another example of the wiring groove 2 formed in the seat pad 1, taken along the line YY of Fig. 2. In Fig. 6, a harness 3 is embedded in the wiring groove 2.

[0033] 6, a protrusion 21 that protrudes inward in the groove width direction is formed on a side surface 2s of the wiring groove 2. In this case, the harness 3 can be fixed more firmly.

[0034] 6, in this embodiment, the protrusion 21 is formed at a position where the harness 3 embedded in the wiring groove 2 can be disposed between the protrusion 21 and the groove bottom 2b of the wiring groove 2. In this case, the protrusion 21 prevents the harness 3 from slipping out of the wiring groove 2, thereby enabling the harness 3 to be fixed more firmly.

[0035] In particular, it is preferable that the protrusions 21 are formed on both side surfaces 2s of the wiring groove 2 as in this embodiment. In this case, the harness 3 can be fixed more firmly and stably. Also, according to the present invention, the protrusions 21 can be formed on only one of the side surfaces 2s of the wiring groove 2. In this case as well, the harness 3 can be fixed more firmly and stably.

[0036] According to the present invention, as yet another example, the protrusion 21 can be formed at a position where the harness 3 embedded in the wiring groove 2 is not disposed between the protrusion 21 and the groove bottom 2b of the wiring groove 2, that is, at a position where the harness 3 embedded in the wiring groove 2 comes into contact with the protrusion 21. In this case, the protrusion 21 can press the harness 3 embedded in the wiring groove 2, thereby more firmly fixing the harness 3.

[0037] (Manufacturing method of seat pad) Next, a method for manufacturing a seat pad according to one embodiment of the present invention will be described. This manufacturing method can be suitably used to manufacture the seat pad 1 described with reference to Fig. 6. Figs. 7 to 9 are diagrams for generally explaining the method for manufacturing a seat pad according to one embodiment of the present invention. Fig. 10 is a perspective cross-sectional view of a main part, generally showing a groove forming protrusion 101 formed in a mold 100 used in the method for manufacturing a seat pad according to one embodiment of the present invention.

[0038] The method for manufacturing a seat pad according to the present invention (hereinafter also referred to as "this manufacturing method") is a method for manufacturing a seat pad using at least a molding die 100 and a foamed polyurethane material to obtain a seat pad including a surface layer 1a made of foamed polyurethane 11, and in which a protrusion 21 is formed on the side surface 2s of a wiring groove 2 formed in the surface layer 1a and protruding inward in the groove width direction.

[0039] 7, in this manufacturing method, a molding die 100 has a groove forming protrusion 101 for forming a wiring groove 2, and a side surface 101 of the groove forming protrusion 101. f A molding die in which a hole 102 is formed is used.

[0040] In addition, this manufacturing method includes a foamed polyurethane material supplying step of supplying a foamed polyurethane material into the inside of the molding die 100, and a forceful removal step of forcibly removing the molded portion formed in the hole 102 of the groove forming protrusion 101 from the hole 102 when removing the preform from the molding die 100.

[0041] In this manufacturing method, the inside of the mold 100 refers to a cavity C formed inside the mold 100. The mold 100 has, for example, an upper mold and a lower mold. In this case, the cavity C is formed by mating the upper mold and the lower mold. The cavity C forms the outer shape of the seat pad 1. In addition, the inside of the mold 100 includes a gap S formed between the mold 100 and the bead method foam 12.

[0042] In this manufacturing method, first, a bead-method foam setting step is performed. Referring to Fig. 7, in the bead-method foam setting step, the bead-method foam 12 is placed inside the mold 100 so that a gap S is formed between the mold 100 and the bead-method foam 12. In this embodiment, the opening 2a of the wiring groove 2 is formed on the lower surface 1f2 of the seat pad 1. In this manufacturing method, the lower surface 1f2 of the seat pad 1 is formed by the cavity surface 110f of the upper mold 110. Therefore, in this manufacturing method, the groove forming protrusion 101 is formed on the cavity surface 110f of the upper mold 110.

[0043] Next, a polyurethane foam material supplying step is performed. In this manufacturing method, a soft polyurethane foam material is supplied into the molding die 100. In this manufacturing method, as shown by the arrow in Fig. 7, the soft polyurethane foam material is supplied from the upper die 110 downward (toward the beads method foam 12). This can improve the moldability of the upper surface of the seat pad 1 (in this embodiment, the bonding surface with the beads method foam 12).

[0044] When the foaming of the polyurethane foam material supplied inside the mold 100 is completed, a preform is completed inside the mold 100 as shown in Fig. 8. In this manufacturing method, the preform has a polyurethane foam 11 as a surface layer 1a, and a bead method foam 12 is embedded as a core (seat pad main body) of the seat pad 1. A molded piece 11a is formed in the preform through a hole 102.

[0045] Next, in this manufacturing method, a forcible removal process is performed. The forcible removal process is a demolding process for removing the preform from the molding die 100. In the demolding process, an upper die 110 and a lower die (not shown) are separated as in a general operation. At this time, as shown in FIG. 9, the molding piece 11a formed in the hole 102 of the preform is forcibly removed from the hole 102 of the groove forming protrusion 101. This allows the protrusion 21 to be formed together with the wiring groove 2 when the seat pad 1 is molded.

[0046] The hole 102 can be either a through hole or a non-through hole (recess). In this embodiment, the hole 102 is a through hole. In this case, the molded piece 11a is a connecting piece that connects the side surface 2s of the wiring groove 2. In this manufacturing method, the molded piece 11a of the preform is forcibly pulled out of the hole 102 of the groove forming protrusion 101, so that the molded piece 11a is divided into one side and the other side of the side surface 2s near the center of the wiring groove 2 in the groove width direction. As a result, the protrusions 21 are formed on both side surfaces 2s of the wiring groove 2 by the simple task of removing the molding die.

[0047] As described above, according to the present manufacturing method, it is possible to easily obtain a seat pad 1 that improves the workability of the wiring work and reduces the cost required for the wiring work.

[0048] In particular, in this manufacturing method, the hole 102 is a through hole. If the hole 102 is a non-through hole, the resin material may not flow well around the hole 102. In contrast, if the hole 102 is a through hole, the resin material flows well around the hole 102, making it easy to mold the protrusion 21 (molded piece 11a). Therefore, according to this manufacturing method, the seat pad 1 can be obtained more easily.

[0049] 10, in this manufacturing method, a plurality of holes 102 are formed in the groove-forming protrusion 101. The holes 102 are formed at intervals in the extending direction of the groove-forming protrusion 101 (the groove length direction of the wiring groove 2). In this case, in the molded seat pad 1, a plurality of protrusions 21 are formed in the wiring groove 2 in the groove length direction of the wiring groove 2. Therefore, in this case, a seat pad 1 capable of fixing the harness 3 more firmly and stably can be obtained. However, according to the present invention, the hole 102 can be formed at only one place in the extending direction of the groove-forming protrusion 101.

[0050] As described above, according to the present invention, it is possible to provide a seat pad that improves the workability of wiring work and reduces the costs required for the wiring work, and a manufacturing method for the seat pad for easily obtaining the seat pad.

[0051] The above is merely an example of one embodiment of the present invention, and various modifications are possible within the scope of the claims. For example, the wiring groove 2 can be formed in at least one of the surface layers 1a on the upper side, lower side, front side, rear side, left side, and right side of the seat pad 1. Although the seat pad 1 is a cushion pad, it can be a combination of a cushion pad and a back pad. In this case, the seat pad according to the present invention can be applied to at least one of the cushion pad, the back pad, and the cushion pad. Also, the seat pad according to the present invention can be only one of the cushion pad, the back pad, and the cushion pad. Furthermore, the seat pad according to the present invention can be a seat pad for a front seat. [Explanation of symbols]

[0052] 1: seat pad, 2: wiring groove, 2a: opening of wiring groove, 2b: bottom surface of wiring groove, 2s: side surface of wiring groove, 21: protrusion, 3: wire harness, 11: polyurethane foam, 12: bead method foam, 100: molding die, 101: groove forming protrusion, 101f: side surface of groove forming protrusion, 102: hole, D: groove depth, W: groove width

Claims

1. A seat pad including a surface layer made of foamed polyurethane, A wiring groove in which a wire harness is wired is formed in the surface layer portion, The wiring groove has a groove width narrower than a diameter of the wire harness and a groove depth deeper than the diameter of the wire harness, a protrusion protruding inward in a groove width direction is formed on a side surface of the wiring groove at a position where the wire harness embedded in the wiring groove can be disposed between the side surface of the wiring groove and a groove bottom of the wiring groove, The protrusions are protrusions formed on both of the two side surfaces of the wiring groove, and the protrusions are each divided into one side and the other side of the two side surfaces by forcibly removing the protrusions near the center of the wiring groove in the groove width direction.

2. The seat pad according to claim 1 , wherein the groove width is a groove width that can be molded using a molding die.

3. 3. The seat pad according to claim 1, wherein the groove depth is three times or more the diameter of the wire harness.

4. The seat pad according to claim 1 , further comprising a bead method foam disposed on the inside of the surface layer.

5. A method for producing a seat pad, using at least a mold and a polyurethane foam material, for obtaining a seat pad including a surface layer portion made of polyurethane foam, and having a protruding portion formed on a side surface of a wiring groove formed in the surface layer portion and protruding inward in a groove width direction, comprising: As the molding die, a molding die having a groove forming protrusion for forming the wiring groove and a hole formed on a side surface of the groove forming protrusion is used, a step of supplying the foamed polyurethane material into the mold; and a forcible removal process for forcibly removing the molded portion formed in the hole portion of the groove forming protrusion portion from the hole portion of the groove forming protrusion portion when removing the molded product from the mold.

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