Seat pad and method for manufacturing a seat pad

Abstract

Improve the quality of the seat pads. [Solution] The sheet pad 10 is formed by overlapping a first sheet member 30 and a second sheet member 40, and at least a portion of the duct 12 is embedded in the foam 20. The first sheet member 30 is positioned on the back side of the sheet pad 10. The second sheet member 40 is positioned on the front side of the sheet pad 10 on the first sheet member 30. The first sheet member 30 has a first projection 34 that protrudes into the interior of the duct 12 and whose tip abuts against the second sheet member 40.

Description

TECHNICAL FIELD

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

BACKGROUND ART

[0002] A seat pad provided with an air conditioning duct has been proposed (see, for example, Patent Document 1). In Patent Document 1, a duct formed by combining two gutter-shaped half members composed of a thermoplastic resin foam and a nonwoven fabric is set in a foam molding die, a foam raw material is foamed in the foam molding die to form a foam, thereby manufacturing a seat pad in which the duct is embedded in the foam.

PRIOR ART DOCUMENTS

PATENT DOCUMENTS

[0003]

PATENT DOCUMENT 1

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] When the foaming pressure generated during foaming of the foam raw material is applied to the duct set in the foam molding die, the quality of the obtained seat pad may deteriorate, such as deformation of the duct or entry of the foam into the interior of the duct.

[0005] The present invention has been proposed in view of the aforementioned problems associated with the conventional art to suitably solve these problems, and an object of the present invention is to provide a high-quality seat pad and a method for manufacturing the seat pad.

MEANS FOR SOLVING THE PROBLEMS

[0006] A first aspect of the seat pad according to the present invention is: A seat pad in which at least a part of a duct formed by stacking a first sheet member and a second sheet member is embedded in a foam, The first sheet member is positioned on the back side of the sheet pad, and the second sheet member is positioned on the front side of the sheet pad of the first sheet member. The gist of the first sheet member is that it has a first projection that protrudes into the interior of the duct and whose tip abuts against the second sheet member.

[0007] A second aspect of the seat pad according to the present invention is the first aspect of the seat pad, The first sheet member has a porous layer on the contact surface with the second sheet member at the tip of the first protrusion. The second sheet member has a hole that is continuous on both sides at the portion that contacts the tip of the first protrusion, The foam may impregnate the porous layer at the tip of the first protrusion through the pores and have a joint that connects the tip of the first protrusion to the second sheet member.

[0008] A third aspect of the seat pad according to the present invention is, in the first or second aspect of the seat pad, The second sheet member may have a second projection that protrudes into the interior of the duct and whose tip abuts against the first sheet member.

[0009] A fourth aspect of the seat pad according to the present invention is the third aspect of the seat pad, The first protrusion has a first recess that opens on the back side of the seat pad, The second protrusion may have a second recess that connects to an opening that opens on the front side of the seat pad.

[0010] A first aspect of the method for manufacturing a sheet pad according to the present invention is: A method for manufacturing a sheet pad in which at least a portion of a duct formed by overlapping a first sheet member and a second sheet member is embedded in a foam, The first sheet member is placed on the cavity surface of the mold, and the second sheet member is positioned opposite the first sheet member. The gist of the method is to form the foam by foaming the foam material supplied to the cavity of the mold while the tip of the first protrusion that protrudes into the duct of the first sheet member is in contact with the second sheet member.

[0011] A second aspect of the method for manufacturing a sheet pad according to the present invention is, in the first aspect of the manufacturing method, The first recess, formed in the first protrusion such that the outer surface of the duct is open, may be fitted into the first mold projection that protrudes from the mold surface of the molding die, and the bottom surface of the first recess may be supported by the tip of the first mold projection during molding.

[0012] A third aspect of the method for manufacturing a sheet pad according to the present invention is, in the first or second aspect of the manufacturing method, The first sheet member has a porous layer on the contact surface with the second sheet member at the tip of the first protrusion. The second sheet member has a hole that is continuous on both sides at the portion that contacts the tip of the first protrusion, The foam material may be impregnated into the porous layer at the tip of the first protrusion through the pores and hardened to join the tip of the first protrusion to the second sheet member.

[0013] A fourth aspect of the method for manufacturing a sheet pad according to the present invention is that in any one of the first to third aspects of the manufacturing method, The first sheet member has a porous layer provided on the side of the second sheet member, The second sheet member is provided with a second projection that protrudes into the interior of the duct, The tip of the second projection has a hole that is continuous on both the front and back sides. The second projection includes a second recess formed such that the outer surface side of the duct is open, The mold has a second mold projection that protrudes from the cavity surface and fits into the second recess, When the second type of protrusion is fitted into the second recess, a raw material channel is formed between the second recess and the second type of protrusion, allowing the raw material for the foam to reach the bottom surface of the second recess. The foam material may be impregnated into the porous layer of the first protrusion through the holes and cured, thereby joining the tip of the second protrusion and the first sheet member together. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0014] According to the seat pad of the present invention, quality can be improved. According to the method for manufacturing a seat pad of the present invention, a high-quality seat pad can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] [Figure 1] It is a plan view showing the seat pad according to the embodiment. [Figure 2] It is a bottom view showing the seat pad according to the embodiment. [Figure 3] It is a cross-sectional view taken along line A-A in Figure 1. [Figure 4] It is an enlarged view of part B in Figure 3. [Figure 5] It is an enlarged view of part C in Figure 3. [Figure 6] It is an explanatory view showing the manufacturing process of the seat pad according to the embodiment. [Figure 7] It is an explanatory view showing the manufacturing process of the seat pad according to the embodiment. [Figure 8] (a) is an enlarged explanatory view showing a position corresponding to part C in Figure 3 in the manufacturing process of the seat pad according to the embodiment, and (b) is a cross-sectional view cut along line D-D of (a). [Figure 9] It is an explanatory view showing the manufacturing process of the seat pad according to the embodiment. [Figure 10] It is a cross-sectional view showing a seat pad provided with a duct according to a modified example. MODE FOR CARRYING OUT THE INVENTION

[0016] Next, preferred embodiments of the sheet pad and the method for manufacturing the sheet pad according to the present invention will be described below with reference to the accompanying drawings. The embodiments and drawings described below are illustrative of some embodiments of the present invention and are not intended to limit the scope to these configurations. They can be modified as appropriate without departing from the spirit of the present invention.

[0017] As shown in Figures 1 and 2, the seat pad 10 according to this embodiment comprises an air conditioning duct 12 and a foam 20, and is used in a form covered with a surface (not shown). In the seat pad 10, at least a portion of the duct 12, which is formed by overlapping the first seat member 30 and the second seat member 40, is embedded in the foam 20 (see Figure 3). The seat pad 10 aims to alleviate heat and stuffiness during use by sending air to the front side of the seat pad 10 or drawing air in from the front side of the seat pad 10 via the duct 12, which constitutes part of the air conditioning system. The seat pad 10 can be applied, for example, to a back pad for a backrest that supports the user's back, or a cushion pad that supports the user's lower body, and is suitable for use in vehicles such as automobiles and trains, ships and airplanes, or furniture such as sofas and chairs. In the following description of the seat pad 10, the side of the seat pad 10 that supports the user is referred to as the front side, and the opposite side is referred to as the back side.

[0018] As shown in Figure 3, in the sheet pad 10 according to the embodiment, the front surface of the sheet pad 10 is formed of foam 20, and the foam 20 is arranged to cover the front surface of the duct 12. In the sheet pad 10, the duct 12 is positioned off-center to the back side of the sheet pad 10, and in this embodiment, a portion of the duct 12 is exposed to the back side of the sheet pad 10. The sheet pad 10 is an insert molded product in which the foam 20 is formed by mold molding with the duct 12 as an insert. The foam 20 can be molded by foaming and curing the foam raw material (raw material for foam 20) in the cavity 52 of the mold 50 (see Figure 7), and known foams such as polyurethane foam can be used. A soft foam is preferred for the foam 20.

[0019] As shown in Figure 3, the duct 12 is formed by overlapping a first sheet member 30 and a second sheet member 40. The duct 12 is formed into a cylindrical shape by overlapping the edges of the first sheet member 30 and the second sheet member 40, which have been pre-formed into a predetermined shape, and joining the edges together. The first sheet member 30 is positioned on the back side of the sheet pad 10, and the second sheet member 40 is positioned on the front side of the sheet pad 10 on the first sheet member 30.

[0020] Each of the first sheet member 30 and the second sheet member 40 is flexible. More specifically, each of the first sheet member 30 and the second sheet member 40 has enough rigidity to maintain its shape and enough flexibility to bend when an external force is applied. Furthermore, each of the first sheet member 30 and the second sheet member 40 is formed by vacuum forming or compression forming of a single-layer or multi-layer sheet material. The first sheet member 30 and the second sheet member 40 can be formed from porous materials such as foam, nonwoven fabric, or felt, or from solid resins that do not have many pores. The first sheet member 30 and the second sheet member 40 may be multi-layered, combining a porous material and a solid resin. In this case, it is preferable to form the inner surfaces of the first sheet member 30 and the second sheet member 40 that face each other when forming the duct 12 with a porous material, as this makes it easier to join them together with adhesive or foam 20. Furthermore, it is preferable to form the outer surfaces of the first sheet member 30 and the second sheet member 40, which become the outer surface of the duct 12 when the duct 12 is formed, with a porous material, as this makes it easier to bond them to the foam 20.

[0021] As shown in Figure 4, the first sheet member 30 and the second sheet member 40 of the duct 12 according to the embodiment have a three-layer structure comprising: an inner porous layer 14 made of a nonwoven fabric such as polypropylene, polyethylene, polyester, nylon, or PET; a film layer 15 disposed outside the inner porous layer 14 and made of a film with very low or no breathability such as polypropylene, polyethylene, polyester, nylon, or PET; and an outer porous layer 16 disposed outside the film layer 15 and made of pressed felt made of various fibrous materials. In the duct 12 according to the embodiment, the contact surfaces of the edges of the first sheet member 30 and the edges of the second sheet member 40, which overlap each other, are the inner porous layer 14, and the inner porous layers 14 are joined together.

[0022] As shown in Figure 4, the edge of the second sheet member 40 (the part that contacts the edge of the first sheet member 30) has an outer hole 41 that penetrates in the front-back direction, and when the foam material is foamed and hardened on the front side of the second sheet member 40, the foam material can be impregnated between the edge of the first sheet member 30 and the edge of the second sheet member 40 through the outer hole 41. The edges of the first sheet member 30 and the edge of the second sheet member 40 may be bonded together with an adhesive, but in this embodiment, the edges of the first sheet member 30 and the edge of the second sheet member 40 are joined by the foam material that has been impregnated and hardened through the outer hole 41 into the inner porous layer 14 which is arranged on their contact surfaces.

[0023] The duct 12 has a back-side vent 32 (see Figure 2) formed in the first sheet member 30 and a front-side vent 42 (see Figure 1) formed in the second sheet member 40. The back-side vent 32 penetrates the first sheet member 30 in the thickness direction and opens on the back side of the sheet pad 10. The front-side vent 42 penetrates the second sheet member 40 in the thickness direction and connects to a front-side vent passage 22 formed in the foam 20 in line with the position of the front-side vent 42 (see Figure 3). The seat pad 10 draws air from the duct 12 through the back ventilation opening 32, thereby drawing air from the front side of the seat pad 10 into the duct 12 through the front ventilation passage 22, or supplies air from the back ventilation opening 32 to the duct 12, thereby sending the air that has passed inside the duct 12 to the front side of the seat pad 10 through the front ventilation passage 22 from the front ventilation opening 42.

[0024] As shown in Figure 3, the first sheet member 30 has a first projection 34 that protrudes into the interior of the duct 12 and whose tip abuts against the second sheet member 40. The first projection 34 protrudes from the back side to the front side and extends in the front-to-back direction into the interior of the duct 12. The first projection 34 is formed by bending the sheet material constituting the first sheet member 30 so that the inside of the duct 12 is convex and the outside of the duct 12 is concave, and has a first recess 36 that opens to the back side of the sheet pad 10. The first projection 34 is provided at a position away from the edge of the first sheet member 30 and away from the back side ventilation opening 32. The first projection 34 is formed in a wall shape that extends in a direction intersecting the front-to-back direction. The tip of the first protrusion 34 may be in contact with any position on the second sheet member 40, but in this embodiment, the tip of the first protrusion 34 is in contact with the tip of the second protrusion 44 on the second sheet member 40, which will be described later. Also, the tip of the first protrusion 34 is joined to the tip of the second protrusion 44. An inner porous layer 14 is placed on the contact surface between the tip of the first protrusion 34 and the second sheet member 40.

[0025] As shown in Figure 3, the second sheet member 40 has a second projection 44 that protrudes into the interior of the duct 12 and whose tip abuts against the first sheet member 30. The second projection 44 protrudes from the front side to the back side and extends in the front-to-back direction inside the duct 12. The second projection 44 is formed by bending the sheet material constituting the second sheet member 40 so that the inside of the duct 12 is convex and the outside of the duct 12 is concave, and has a second recess 46 that connects to the front opening (opening) 24 that opens to the front side of the sheet pad 10 in the foam 20. The second projection 44 is provided at a position away from the edge of the second sheet member 40 and away from the front ventilation opening 42. The second projection 44 is formed in a shape that supports the first sheet member 30, such as being formed as a wall shape extending in a direction intersecting the front-to-back direction as in the embodiment, or as a columnar shape. Here, the second protrusion 44 may be formed in the same shape as the first protrusion 34, or in a different shape from the first protrusion 34. The tip of the second protrusion 44 may abut at any position on the first sheet member 30, but in this embodiment, the tip of the second protrusion 44 abuts against the tip of the first protrusion 34 on the first sheet member 30.

[0026] As shown in Figure 5, an inner porous layer 14 is arranged on the contact surface with the first sheet member 30 at the tip of the second protrusion 44, and the tip of the first protrusion 34 and the second protrusion 44 are in contact with each other via the inner porous layer 14. The tip of the second protrusion 44 (the part of the second sheet member 40 that contacts the first protrusion 34) has an internal hole (perforation) 48 that penetrates in the front-back direction, and when foaming and hardening the foam material on the front side of the second sheet member 40, the foam material can be impregnated between the tip of the first protrusion 34 and the second protrusion 44 via the internal hole 48. The foam 20 according to this embodiment is impregnated into the inner porous layer 14 at the tip of the first protrusion 34 via the internal hole 48 and has a joint portion 26 that joins the tip of the first protrusion 34 and the second sheet member 40. In this embodiment, the tip of the first protrusion 34 and the tip of the second protrusion 44 are joined together by a foam material that has been impregnated and hardened through the inner porous layer 14, which is arranged on the contact surfaces of the two protrusions, via the inner pores 48.

[0027] Next, the manufacturing method of the sheet pad 10 described above will be explained. First, a sheet material for the first sheet member 30 is molded to form a first sheet member 30 having a first protrusion 34. A back-side ventilation opening 32 is formed in the first sheet member 30 by punching or the like. Similarly, a sheet material for the second sheet member 40 is molded to form a second sheet member 40 having a second protrusion 44. Next, a front-side ventilation opening 42 is formed in the second sheet member 40 by punching or the like. In addition, an outer hole 41 is formed at the edge of the second sheet member 40, and an inner hole 48 is formed at the tip of the second protrusion 44.

[0028] As shown in Figure 6(a), with the upper mold 60 and lower mold 70 of the molding die 50 open, the set holes (not shown) formed on the edge of the first sheet member 30 are fitted into the set pins 62 that protrude from the cavity surface (see Figure 7) forming the cavity 52 in the upper mold 60 of the molding die 50, thereby installing the first sheet member 30 in contact with the cavity surface of the upper mold 60. At this time, the first recess 36 of the first sheet member 30 is fitted into the first mold projection 64 that protrudes from the cavity surface of the upper mold 60. Next, the set holes (not shown) formed on the edge of the second sheet member 40 are fitted into the set pins 62 of the upper mold 60, and the second sheet member 40 is positioned facing the front side of the first sheet member 30 by overlapping their edges. As a result, the tip of the first projection 34 of the first sheet member 30 and the tip of the second projection 44 of the second sheet member 40 are in contact with each other when the duct 12 is formed, and the duct 12 is installed in the mold 50.

[0029] The foam material is supplied to the lower mold 70 of the molding die 50 (see Figure 6(b)), and the upper mold 60 and lower mold 70 are closed. When the molding die 50 is closed, the closing protrusion 72 that protrudes from the cavity surface forming the cavity 52 in the lower mold 70 fits into the front side vent 42 of the second sheet member 40, blocking the front side vent 42 (see Figure 7(a)). In addition, the second mold protrusion 74 that protrudes from the cavity surface of the lower mold 70 fits into the second recess 46 of the second sheet member 40, and a material flow path 76 (see Figure 8(a)) is formed between the second mold protrusion 74, which is formed to be slightly smaller than the second recess 46, and the second recess 46, extending from the opening side of the second recess 46 to the bottom side of the second recess 46. A groove 74a is formed on the tip surface of the second type protrusion 74, corresponding to the opening position of the inner bore 48 (see Figure 8(b)), allowing foam material to flow from the raw material flow path into the inner bore 48 through this groove 74a.

[0030] As the foaming material foams and expands from bottom to top, it fills the cavity 52 and impregnates the outer porous layer 16 of the second sheet member 40. Then, with a portion of the duct 12 on the second sheet member 40 side embedded and joined, the foam 20 is molded into a predetermined shape in the cavity 52 (see Figure 7(b)). At this time, the foaming material reaches the bottom of the second recess 46 through the material flow path 76 between the second mold protrusion 74 and the second recess 46, and through the internal hole 48 formed at the bottom of the second recess 46 (the tip of the second protrusion 44), the foaming material impregnates the inner porous layer 14 at the tip of the second protrusion 44 and the inner porous layer 14 at the tip of the first protrusion 34. Then, as the impregnated foaming material hardens, the tip of the first protrusion 34 and the tip of the second protrusion 44 are joined together. Furthermore, the foam material impregnates the inner porous layer 14 of the edge of the second sheet member 40 and the inner porous layer 14 of the edge of the first sheet member 30 through the outer holes 41 formed on the edge of the second sheet member 40 and hardens, thereby joining the edge of the first sheet member 30 and the edge of the second sheet member 40. This results in a sheet pad 10 in which the duct 12 is partially embedded in the foam 20. Then, the mold 50 is opened and the obtained sheet pad 10 is removed from the mold 50 (see Figure 9).

[0031] The manufacturing method of the sheet pad 10 described above involves forming a foam 20 by foaming the foam raw material supplied to the cavity 52 of the mold 50 while the tip of the first protrusion 34 of the first sheet member 30, which protrudes into the duct 12, is in contact with the second protrusion 44 of the second sheet member 40. When forming the foam 20, the second sheet member 40 is pushed from bottom (front side) to top (back side) by the foam raw material that foams and expands from bottom to top. At this time, since the first protrusion 34 of the first sheet member 30 is in contact with the second protrusion 44 of the second sheet member 40 from above, the second sheet member 40 is supported from above, and deformation of the second sheet member 40 due to the expansion of the foam raw material can be suppressed. In this way, by suppressing the deformation of the second sheet member 40 during the molding of the foam 20, the possibility of foam material entering the duct 12 from unintended places such as between the closing protrusion 72 and the front ventilation opening 42, or at the joint between the first sheet member 30 and the second sheet member 40 can be reduced. According to the manufacturing method of the sheet pad 10 described above, it is difficult for foam material to enter the duct 12, so the quality of the sheet pad 10 in which the duct 12 is partially embedded in the foam 20 can be improved. In addition, the effort required for preparatory work such as sealing to prevent foam material from entering the duct 12, and post-work such as removing foam 20 that has entered the duct 12 can be reduced, and the sheet pad 10 can be manufactured efficiently.

[0032] The manufacturing method for the sheet pad 10 described above involves fitting the first recess 36, which is formed in the first protrusion 34 so that the outer surface of the duct 12 is open, into the first mold projection 64 that protrudes from the cavity surface of the upper mold 60, and supporting the bottom surface of the first recess 36 with the tip of the first mold projection 64 to form the foam 20. By fitting the first recess 36 into the first mold projection 64 of the upper mold 60 and installing the first sheet member 30 in the upper mold 60, the first sheet member 30 can be positioned. Furthermore, during the molding of the foam 20, the first protrusion 34 itself is supported by the first mold projection 64 of the upper mold 60, so that the second sheet member 40 can be properly supported against the expansion of the foam raw material. This improves the quality of the resulting sheet pad 10.

[0033] The manufacturing method for the sheet pad 10 described above involves molding the foam 20 with the tip of the first protrusion 34 of the first sheet member 30, which protrudes into the duct 12, in contact with the tip of the second protrusion 44 of the second sheet member 40, which also protrudes into the duct 12. This reduces the protrusion dimension of the first protrusion 34, making it easier to form the first protrusion 34 by vacuum forming or the like. Furthermore, when the mold 50 is closed, the second recess 46 formed in the second protrusion 44 so that the outer surface of the duct 12 is open fits into the second mold protrusion 74 protruding from the cavity surface of the lower mold 70, allowing the second sheet member 40 to be positioned. Since a raw material flow path 76 is formed between the second mold protrusion 74 and the second recess 46, the foam material reaches the bottom surface of the second recess 46 via the raw material flow path 76 during the molding of the foam 20. Furthermore, since an internal hole 48 is formed on the bottom surface of the second recess 46, the foam material impregnates and hardens into the inner porous layer 14 at the tip of the first protrusion 34 through the internal hole 48. This joins the tip of the first protrusion 34 and the tip of the second protrusion 44. In this way, the tip of the first protrusion 34 and the tip of the second protrusion 44 are joined during the molding of the foam 20, thus eliminating the need to pre-bond the first protrusion 34 and the second protrusion 44 to the mating part, and enabling the efficient manufacture of the sheet pad 10.

[0034] In the aforementioned method for manufacturing the sheet pad 10, since an outer hole 41 is formed at the edge of the second sheet member 40, the foam material impregnates and hardens into the inner porous layer 14 at the edge of the first sheet member 30 through the outer hole 41, thereby joining the edge of the first sheet member 30 and the edge of the second sheet member 40. In this way, since the edges of the first sheet member 30 and the edge of the second sheet member 40 are joined during the molding of the foam 20, the effort of pre-bonding the first sheet member 30 and the second sheet member 40 can be eliminated, and the sheet pad 10 can be manufactured efficiently.

[0035] In the sheet pad 10, the first sheet member 30 has a first projection 34 that protrudes into the duct 12 and whose tip abuts against the second sheet member 40, so that the second sheet member 40 can be supported by the first projection 34. As a result, as described above, the intrusion of foam material into the duct 12 is suppressed when the foam 20 is molded, and deformation of the duct 12 is suppressed when the sheet pad 10 is used. Therefore, the sheet pad 10 according to this embodiment is of good quality.

[0036] In the sheet pad 10, the second sheet member 40 has a second protrusion 44 that extends into the duct 12 and whose tip abuts against the first sheet member 30, so that the second sheet member 40 can be supported by the second protrusion 44. As a result, as described above, the intrusion of foam material into the duct 12 is suppressed when the foam 20 is molded, and deformation of the duct 12 is suppressed when the sheet pad 10 is used. Therefore, the sheet pad 10 according to this embodiment is of good quality.

[0037] The first sheet member 30 has an inner porous layer 14 on the contact surface with the second sheet member 40 at the tip of the first protrusion 34. The second sheet member 40 has an internal bore portion 48 that is continuous on both sides at the tip of the second protrusion 44, which is the part that contacts the tip of the first protrusion 34. The foam 20 is impregnated into the inner porous layer 14 at the tip of the first protrusion 34 via the internal bore portion 48 and has a joining portion 26 that joins the tip of the first protrusion 34 and the tip of the second protrusion 44. In this way, the sheet pad 10 joins the tip of the first protrusion 34 and the second sheet member 40 (the tip of the second protrusion 44) by the joining portion 26 of the foam 20 without using an adhesive, so problems caused by adhesives do not occur.

[0038] The rigidity of the first protrusion 34 can be improved by giving it a shape that has a first recess 36 that opens to the back side of the seat pad 10. Similarly, the rigidity of the second protrusion 44 can be improved by giving it a shape that has a second recess 46 that connects to a front opening 24 that opens to the front side of the seat pad 10.

[0039] (Example of change) In addition to the matters described above, the invention may also be applied in the following ways, for example. Furthermore, the present invention is not limited to the embodiments and the specific examples of modifications described below. (1) In the embodiment, the tip of the first protrusion 34 is brought into contact with the tip of the second protrusion 44. However, the embodiment is not limited to this, and for example, as shown in Figure 10, the tip of the first protrusion 34 may be brought into contact with a part of the second sheet member 40 other than the second protrusion 44 (a part that is pressed by the foam 20 during molding). In this case, similar to the embodiment, an internal bore 48 continuous on both sides may be formed in the part of the second sheet member 40 that contacts the tip of the first protrusion 34, and the tip of the first protrusion 34 and the second sheet member 40 may be joined by a foam raw material that impregnates and hardens in the inner porous layer 14 of the tip of the first protrusion 34 via the internal bore 48. (2) In the embodiment, the tip of the second protrusion 44 is brought into contact with the tip of the first protrusion 34. However, the embodiment is not limited to this, and for example, as shown in Figure 10, the tip of the second protrusion 44 may be brought into contact with a part of the first sheet member 30 other than the first protrusion 34. In this case, similar to the embodiment, an internal bore 48 continuous on both sides may be formed at the tip of the second protrusion 44, and the tip of the second protrusion 44 and the first sheet member 30 may be joined by a foam material that impregnates and hardens in the inner porous layer 14 of the first sheet member 30 via the internal bore 48. (3) In this embodiment, the tip of the first protrusion 34 is joined to the second sheet member 40, but the invention is not limited to this, and the tip of the first protrusion 34 may be in contact with the second sheet member 40 without being joined. (4) In this embodiment, the tip of the second protrusion 44 is joined to the first sheet member 30, but the invention is not limited to this, and the tip of the second protrusion 44 may not be joined to the first sheet member 30 but may simply be touching it. (5) In this embodiment, the first protrusion 34 is formed in the shape of a wall extending in a direction intersecting the front-back direction, but it is not limited to this, and any shape that provides support between it and the second sheet member 20 is acceptable, such as forming it in the shape of a column. (6) The tip of the first protrusion 34 may be attached to the second sheet member 40 with an adhesive or the like. Alternatively, the tip of the second protrusion 44 may be attached to the first sheet member 30 with an adhesive or the like. (7) The edges of the first sheet member and the edges of the second sheet member may be bonded together with an adhesive or the like. [Explanation of symbols]

[0040] 10 Seat pad, 12 Duct, 20 Foam, 24 Front opening (opening), 26 Joint portion, 30 First sheet member, 34 First protruding portion, 36 First recess, 40 Second sheet member, 44 Second protrusion, 46 Second recess, 48 ​​Internal hole (hole), 50 mold, 52 cavity, 64 first mold protrusion, 74 second mold protrusion, 76 Raw material flow path

Claims

1. A sheet pad in which at least a portion of a duct formed by overlapping a first sheet member and a second sheet member is embedded in foam, The first sheet member is positioned on the back side of the sheet pad, and the second sheet member is positioned on the front side of the sheet pad of the first sheet member. The first sheet member is a sheet pad having a first projection that protrudes into the interior of the duct and whose tip abuts against the second sheet member.

2. The first sheet member has a porous layer on the contact surface with the second sheet member at the tip of the first protrusion. The second sheet member has a hole that is continuous on both sides at the portion that contacts the tip of the first protrusion, The sheet pad according to claim 1, wherein the foam impregnates the porous layer at the tip of the first protrusion through the holes, and has a joint that joins the tip of the first protrusion and the second sheet member.

3. The sheet pad according to claim 1, wherein the second sheet member has a second projection that protrudes into the interior of the duct and whose tip abuts against the first sheet member.

4. The first protrusion has a first recess that opens on the back side of the seat pad, The seat pad according to claim 3, wherein the second protrusion is connected to a second recess that opens to the front side of the seat pad.

5. A method for manufacturing a sheet pad in which at least a portion of a duct formed by overlapping a first sheet member and a second sheet member is embedded in a foam, The first sheet member is placed on the cavity surface of the mold, and the second sheet member is positioned opposite the first sheet member. A method for manufacturing a sheet pad, comprising forming the sheet pad by foaming the foam material supplied to the cavity of the mold while the tip of a first protrusion that protrudes into the interior of the duct in the first sheet member is in contact with the second sheet member.

6. A method for manufacturing a sheet pad according to claim 5, wherein the first recess formed in the first protrusion such that the outer surface side of the duct is open is fitted into the first mold projection protruding from the mold surface of the molding die, and the bottom surface of the first recess is supported by the tip of the first mold projection for molding.

7. The first sheet member has a porous layer on the contact surface with the second sheet member at the tip of the first protrusion. The second sheet member has a hole that is continuous on both sides at the portion that contacts the tip of the first protrusion, The method for manufacturing a sheet pad according to claim 5, wherein the raw material for the foam impregnates the porous layer at the tip of the first protrusion through the pores and hardens to join the tip of the first protrusion and the second sheet member.

8. The first sheet member has a porous layer provided on the side of the second sheet member, The second sheet member is provided with a second projection that protrudes into the interior of the duct, The tip of the second projection has a hole that is continuous on both the front and back sides. The second projection includes a second recess formed such that the outer surface side of the duct is open, The mold has a second mold projection that protrudes from the cavity surface and fits into the second recess, When the second type of protrusion is fitted into the second recess, a raw material channel is formed between the second recess and the second type of protrusion, allowing the raw material for the foam to reach the bottom surface of the second recess. The method for manufacturing a sheet pad according to claim 5, wherein the raw material of the foam impregnates the porous layer of the first protrusion through the pores and hardens, thereby joining the tip of the second protrusion and the first sheet member.

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