Seat pad, seat pad molding tool and manufacturing method of seat pad

Abstract

To provide a seat pad including a ventilation path formed therein and having a simplified structure, a seat pad molding tool for molding the seat pad, and a manufacturing method of the seat pad.SOLUTION: A seat pad comprises a pad body, and a hard pad overlapping a pad back side of the pad body, where a ventilation path is formed penetrating in a pad thickness direction from the pad body to the hard pad. The ventilation path includes a first vent hole formed in the pad body, and a second vent hole formed in the hard pad. The hard pad includes a step surface that forms a part of the ventilation path and is exposed to a surface side of the pad in the pad thickness direction at a boundary position between the pad body and the hard pad in the pad thickness direction, where the step surface is formed over an entire area around an outer edge of the second vent hole located at the boundary.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] 2. Description of the Related Art Seat pads having air passages formed therein for blowing air toward a seated occupant or for sucking air around the seated occupant have been conventionally known.

[0003] Such a seat pad is disclosed in Patent Document 1. The seat member as a seat pad described in Patent Document 1 is composed of an insert member having a first through hole that communicates with a passage through which air flows and opens on one side, and a second through hole that opens on the other side and communicates with the passage, and a foamed soft member in which a third passage that communicates with the second through hole is formed.

[0004] Patent Document 1 also discloses a method for manufacturing a seat member as the above-mentioned seat pad. The method for manufacturing a seat member as a seat pad described in Patent Document 1 includes a step of setting an insert member in an upper mold and directing a second through hole of the insert member to a cavity of a lower mold that molds the seating surface side. In the method for manufacturing a seat member as a seat pad described in Patent Document 1, when the insert member is set in the upper mold, the unevenness formed on the insert member and the unevenness formed on the upper mold are mated to position the insert member relative to the upper mold. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6894675 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the seat member as a seat pad described in Patent Document 1 needs to have an unevenness for positioning the insert member in the upper mold in addition to the configuration of the ventilation path, so the structure is likely to become complicated. The complication of the seat pad structure is not preferable from the viewpoint of improving the degree of freedom in designing the seat pad.

[0007] An object of the present disclosure is to provide a seat pad having an air passage formed therein, which allows for a simplified structure, a seat pad molding die for molding this seat pad, and a method for manufacturing this seat pad. [Means for solving the problem]

[0008] The seat pad according to the first aspect of the present disclosure includes: (1) A seat pad comprising a pad main body and a hard pad portion that is harder than the pad main body and overlaps a back side of the pad main body, and at least one ventilation path is formed penetrating through the pad thickness direction from the pad main body to the hard pad portion, The ventilation passage includes a first ventilation hole formed in the pad main body portion and a second ventilation hole formed in the hard pad portion, the hard pad portion includes a step surface that forms a part of the air passage and is exposed to a surface side of the pad in the pad thickness direction at a boundary between the pad main body portion and the hard pad portion in the pad thickness direction, The step surface is a seat pad that is formed over the entire area around the outer edge of the second air vent located at the boundary.

[0009] A seat pad according to one embodiment of the present disclosure includes: (2) The sheet pad according to the above-mentioned (1), wherein the first ventilation hole has a cross-sectional area perpendicular to the thickness direction of the pad that gradually increases from the rear end of the pad in the thickness direction of the pad to the front end of the pad.

[0010] A seat pad according to one embodiment of the present disclosure includes: (3) The seat pad according to claim 1 or 2, wherein the cross-sectional shape in the thickness direction of the pad of the recessed corner portion that is formed by the pad main body portion and the hard pad portion and that forms part of the air passage is an arc shape or a polygon shape.

[0011] The seat pad molding die according to the first aspect of the present disclosure comprises: (4) A seat pad molding die including an upper die and a lower die disposed below the upper die, for integrally molding a pad main body and a hard pad portion harder than the pad main body, The upper mold and the lower mold each include at least one pair of protrusions having opposing surfaces at their tips, When the upper mold and the lower mold are closed, the opposing surface of the convex portion of the lower mold includes an overlapping surface that overlaps with the opposing surface of the convex portion of the upper mold in a plan view, and a non-overlapping surface that does not overlap with the opposing surface of the convex portion of the upper mold in a plan view, The non-overlapping surface is a seat pad mold that surrounds the entire area around the outer edge of the overlapping surface.

[0012] A method for manufacturing a seat pad according to a first aspect of the present disclosure includes: (5) A method for manufacturing a seat pad, comprising the steps of: using a molding die having an upper die and a lower die disposed below the upper die; forming a pad main body portion and a hard pad portion harder than the pad main body portion in an integrated manner; a foam molding step of covering a molding surface of the upper mold with the hard pad portion and foam molding the pad main body portion in a state where the upper mold and the lower mold are closed, The upper mold and the lower mold each include at least one pair of protrusions having opposing surfaces at their tips, This is a method for manufacturing a seat pad, in which, on the opposing surface of the convex portion of the lower mold, the portion that abuts against the hard pad portion is defined as a contact surface, and the portion that does not abut against the hard pad portion is defined as a non-contact surface, during the foam molding step, the abutment surface surrounds the entire outer edge of the non-contact surface. Effect of the Invention

[0013] According to the present disclosure, it is possible to provide a seat pad having an air passage formed therein, which allows for a simplified structure, a seat pad molding die for molding this seat pad, and a method for manufacturing this seat pad. [Brief description of the drawings]

[0014] [Figure 1] 1 is an external perspective view of a vehicle seat including a seat pad according to an embodiment of the present disclosure; [Diagram 2] 2 is a plan view showing a surface of a cushion pad of the seat pad shown in FIG. 1. FIG. [Diagram 3] 3 is a cross-sectional view taken along line aa of the cushion pad of the seat pad shown in FIG. 2. [Figure 4A] 4 is an enlarged view of a first ventilation hole and a second ventilation hole shown in FIG. 3. FIG. [Figure 4B] 4B is a diagram showing another example of the configuration of the first ventilation hole and the second ventilation hole shown in FIG. 4A. FIG. [Figure 4C] 4B is a diagram showing another example of the configuration of the first ventilation hole and the second ventilation hole shown in FIG. 4A. FIG. [Figure 5A] FIG. 4B is a cross-sectional view taken along line bb in FIG. 4A. [Figure 5B] 5B is a cross-sectional view of another example of the first ventilation hole and the second ventilation hole shown in FIG. 4A at the same position as FIG. 5A. [Figure 6] 2 is a left-right cross-sectional view showing a seat pad molding die for molding the seat pad shown in FIG. 1. [Figure 7A] 7 is an enlarged view showing paired convex portions of the upper and lower dies of the seat pad molding die shown in FIG. 6. FIG. [Figure 7B] 7B is a diagram showing a state in which the upper and lower dies are closed following the state shown in FIG. 7A. FIG. [Figure 8] FIG. 7C is a cross-sectional view taken along line cc in FIG. 7B. [Figure 9A]7 is a diagram showing a state in which a hard pad portion is placed on the upper die of the seat pad molding die shown in FIG. 6, and a foaming resin material is injected into the lower die molding surface of the lower die. [Figure 9B] 9B is a diagram showing a state in which the upper and lower dies are closed, following the state shown in FIG. 9A. FIG. [Figure 9C] FIG. 9C is a diagram showing a state in which the pad main body is foam-molded from the state shown in FIG. 9B. [Figure 10] 9D is an enlarged view showing the periphery of paired convex portions of the upper and lower molds in the state shown in FIG. 9C. FIG. [Figure 11] FIG. 11 is a cross-sectional view taken along line dd in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The uses of the seat pad of the present disclosure, the seat pad manufactured by the seat pad molding die of the present disclosure, and the seat pad manufactured by the seat pad manufacturing method of the present disclosure are not particularly limited, but are suitable for use in any vehicle seat and any vehicle seat pad, and are particularly suitable for use in vehicle seats and vehicle seat pads.

[0016] Hereinafter, embodiments of a seat pad, a seat pad mold, and a method for manufacturing a seat pad according to the present disclosure will be described with reference to the drawings. In each drawing, the same reference numerals are used to designate common components.

[0017] Fig. 1 is an external perspective view showing a vehicle seat 100 including a seat pad 1 as one embodiment of a seat pad according to the present disclosure. Fig. 2 is a plan view showing a surface FS of a cushion pad 10 of this embodiment as viewed in plan. Fig. 3 shows a cross section of the cushion pad 10 of Fig. 2 taken along line aa in Fig. 2. The seat pad 1 of this embodiment is configured as a vehicle seat pad, and the vehicle seat 100 of this embodiment includes the cushion pad 10 as the seat pad 1 for a seated person to sit on, and a back pad 20 as the seat pad 1 for supporting the back of the seated person.

[0018] In addition to the seat pad 1, the vehicle seat 100 includes, for example, a cushion pad 10 as the seat pad 1 and a cover member 30 that covers the pad front side (seat occupant side) of the back pad 20, a frame that supports the cushion pad 10 from the lower side, which is the back side of the pad, a frame installed on the rear side, which is the back side of the pad of the back pad 20, and a headrest 40 that is installed on the upper side of the back pad 20 and supports the head of the seat occupant. The cover member 30 may be made of, for example, a breathable material (cloth, etc.). In FIG. 1, for convenience of explanation, the cover member 30 is shown by a solid line, and the cushion pad 10 and back pad 20 as the seat pad 1 covered by the cover member 30 are shown by a dashed line.

[0019] In this embodiment, the cushion pad 10 and the back pad 20 are configured separately from each other, but may be configured integrally with each other. Also, in this embodiment, the headrest 40 is configured separately from the back pad 20, but may be configured integrally with the back pad 20.

[0020] In this disclosure, when describing the vehicle seat 100 and the seat pad 1, the directions "up," "down," "left," "right," "front," and "rear" as seen by a person seated in the vehicle seat 100 will be referred to simply as "up," "down," "left," "right," "front," and "rear," respectively.

[0021] In addition, in this disclosure, when describing the seat pad molding mold 200 (see Figure 6, etc.) for molding the seat pad 1, the directions corresponding to the "left," "right," "front," and "rear" directions when viewed from a person seated on the seat pad 1 molded by the seat pad molding mold 200 are simply referred to as "left," "right," "front," and "rear," respectively, and the vertical directions "up" and "down" when molding the seat pad 1 are simply referred to as "up" and "down," respectively.

[0022] In the present disclosure, the "pad thickness direction TD of the seat pad 1" (hereinafter sometimes simply referred to as "pad thickness direction TD") refers to the approximate up-down direction in the case of the cushion pad 10, which is the direction from the upper surface FS (upper surface) which is the pad front side of the cushion pad 10 toward the lower back surface BS (lower surface) which is the pad back side, and the direction from the back surface BS toward the front surface FS. In the case of the back pad 20, the "pad thickness direction TD" refers to the approximate front-rear direction in the case of the back pad 20, which is the direction from the front surface FS (front surface) which is the pad front side of the back pad 20 toward the rear back surface BS (rear surface) which is the pad back side, and the direction from the back surface BS toward the front surface FS.

[0023] 3, the seat pad 1 includes a pad main body 50 and a hard pad portion 60 overlapping the pad main body 50 in the pad thickness direction TD. In the present disclosure, in the pad thickness direction TD, the direction from the hard pad portion 60 toward the pad main body 50 may be referred to as the "pad front side F," and the direction from the pad main body 50 toward the hard pad portion 60 may be referred to as the "pad back side B."

[0024] In the following, the cushion pad 10 as the seat pad 1 will be mainly described.

[0025] FIG. 1 shows a state in which the cushion pad 10 is connected to a fan 110, which is an external device. The fan 110 of this embodiment can suck / send air. When the fan 110 of this embodiment is driven, air is sucked / sent from the surface FS (upper surface) of the cushion pad 10 through the air passage 2 formed in the cushion pad 10. As a result, in the vehicle seat 100 of this embodiment, air is sucked / sent from the surface FS (upper surface) of the cushion pad 10, so that a seated person seated in the vehicle seat 100 can be given a warm feeling (warm sensation) or a cool feeling (cold sensation). The installation location of the fan 110 is not particularly limited, and it may be installed, for example, below the cushion pad 10. Note that the external device connected to the seat pad 1 is not limited to a fan as long as it can send or suck air, and may be, for example, an air conditioner.

[0026] 1 and 2, the cushion pad 10 has a main pad portion 11 configured to support the buttocks and thighs of a seated person from below, a pair of side pad portions 12 located on both the left and right sides of the main pad portion 11, raised above the main pad portion 11, and configured to support the seated person from both the left and right sides, and a back pad opposing portion 13 located on the rear side of the main pad portion 11 and configured to be arranged opposite the back pad 20 in the up-down direction. The main pad portion 11 has a lower thigh portion 11t configured to support the thighs of the seated person from below, and a lower buttock portion 11h located rearward of the lower thigh portion 11t and configured to support the buttocks of the seated person from below.

[0027] 1 and 2, a plurality of air passages 2 are formed in the underside of the buttocks 11h of the main pad portion 11 of the cushion pad 10 of this embodiment. In this embodiment, a plurality of air passages 2 are formed in the cushion pad 10, but this is not limited to the configuration, and it is sufficient that at least one air passage 2 is formed. However, if a plurality of small-diameter air passages 2 are formed in the seat pad as in this embodiment, it is possible to promote the suction / exhaust of air from the surface FS compared to a configuration in which only one small-diameter air passage 2 is formed, and it is possible to give a warmer or cooler feeling to the occupant seated in the vehicle seat 100.

[0028] In addition, although the air passages 2 in this embodiment are formed in multiple positions in the left-right direction and the front-back direction of the cushion pad 10, the present invention is not limited to this configuration, and may be configured such that multiple air passages 2 are formed only in either the left-right direction or the front-back direction of the cushion pad. However, if multiple air passages 2 are arranged in each of the left-right direction and the front-back direction as in this embodiment, the influence of variations in the amount of air sucked in or sent out depending on the left-right position and the front-back position of the cushion pad can be reduced. Note that, when the seat pad 1 is the back pad 20, if multiple air passages are arranged in each of the left-right direction and the up-down direction, the influence of variations in the amount of air sucked in or sent out depending on the left-right position and the up-down position of the back pad 20 can be reduced.

[0029] In addition, although the air passage 2 in this embodiment is formed only in the underbuttocks 11h of the main pad portion 11, the present invention is not limited to this configuration, and may be formed, for example, in both the underbuttocks 11h and the under-thighs 11t of the main pad portion 11, or may be formed only in the under-thighs 11t of the main pad portion 11. However, if the air passage 2 is formed in the underbuttocks 11h of the main pad portion 11 as in this embodiment, a feeling of warmth or coolness can be reliably imparted to the occupant seated in the vehicle seat 100.

[0030] As described above, as shown in FIG. 3, the cushion pad 10 as the seat pad 1 includes the pad main body 50 and the hard pad portion 60 overlapping the pad main body 50 in the pad thickness direction TD. In this embodiment, the hard pad portion 60 is disposed on the lower side of the pad main body 50, which is the pad back side B. The cushion pad 10 of this embodiment further includes a lid member 80 attached to the lower side of the pad back side B of the hard pad portion 60. In this embodiment, the front surface FS (upper surface) of the cushion pad 10 is constituted by the pad main body 50. In this embodiment, the back surface BS (lower surface) of the cushion pad 10 is constituted by a part of the lower surface of the pad main body 50, a part of the side surface of the hard pad portion 60, and the lower surface of the lid member 80. As shown in FIG. 3, the cushion pad 10 as the seat pad 1 has an air passage 2 penetrating through the pad main body 50 and the hard pad portion 60 in the pad thickness direction TD.

[0031] The material for forming the pad main body 50 is preferably a foamed resin having elasticity, and polyurethane foam is particularly preferred from the viewpoints of moldability and seating comfort. The hard pad portion 60 is harder than the pad main body 50. The material for forming the hard pad portion 60 is preferably a foamed resin made of a synthetic resin such as an olefin resin, and foamed polypropylene is particularly preferred from the viewpoints of light weight, heat insulation, cushioning against external stress, heat resistance, and durability. By providing the hard pad portion 60 that is harder than the pad main body 50, the seat pad 1 can suppress the occurrence of the so-called submarine phenomenon in which the seated person slips into the seat pad 1.

[0032] 3, the air passage 2 penetrates the cushion pad 10 in the pad thickness direction TD. More specifically, the air passage 2 includes a first air vent 51 formed in the pad main body 50 and a second air vent 61 formed in the hard pad portion 60. In addition to the first air vent 51 and the second air vent 61, the air passage 2 of this embodiment includes an air flow path 62 formed in the hard pad portion 60 and a hole 81 formed in the lid member 80.

[0033] 3, the first ventilation hole 51 penetrates the pad main body 50 in the pad thickness direction TD. The second ventilation hole 61 penetrates the hard pad portion 60 in the pad thickness direction TD and is arranged so as to be connected to the first ventilation hole 51. The air flow path 62 in this embodiment is defined by a recess 63 formed on the lower surface of the pad back side B of the hard pad portion 60. The air flow path 62 in this embodiment extends in the front-rear direction and the left-right direction and is connected to each of the multiple second ventilation holes 61 formed in the hard pad portion 60.

[0034] The lid member 80 may be formed by laminating, for example, a non-breathable resin layer and a felt layer. The lid member 80 of this embodiment covers the entire area of ​​the recess 63 of the hard pad portion 60 from the pad back side B. The lid member 80 may be bonded, for example, to an end face that forms the edge of the recess 63 on the lower surface of the pad back side B of the hard pad portion 60 by an adhesive.

[0035] The cover member 80 of this embodiment has a hole 81 formed therein, penetrating the cover member 80 in the pad thickness direction TD. The air passage 2 of this embodiment is connected to the outside of the back side B of the pad through the hole 81. The cushion pad 10 of this embodiment is connected to the fan 110 by attaching the suction port / blowout port of the fan 110 to the hole 81. The cushion pad 10 includes the cover member 80, so that the fan 110 can efficiently suck in / blow out air.

[0036] A convex portion 250U (see FIG. 6, etc.) of an upper die 200U of a sheet pad molding die 200 (see FIG. 6, etc.) described later can be inserted into the second ventilation hole 61 of the hard pad portion 60. By inserting the convex portion 250U of the upper die 200U of the sheet pad molding die 200 into the second ventilation hole 61 of the hard pad portion 60, the hard pad portion 60 can be positioned relative to the upper die 200U in the manufacturing process of the sheet pad 1. Therefore, according to the sheet pad 1, it is not necessary to provide a structure for positioning the hard pad portion 60 relative to the upper die 200U in addition to the second ventilation hole 61. This makes it possible to obtain a seat pad 1 with a simple structure in which the ventilation path 2 is formed. The details of the sheet pad molding die 200 and the manufacturing method of the seat pad 1 using this sheet pad molding die 200 will be described later (see FIG. 6, etc.).

[0037] FIG. 4A shows an enlarged view of the first ventilation opening 51 and the second ventilation opening 61 of the cushion pad 10 shown in FIG. 3. FIG. 5A is a cross-sectional view taken along the line bb in FIG. 4A. In FIG. 5A, the outer edge 51a of the first ventilation opening 51 located at the boundary BL (hereinafter, sometimes simply referred to as the "boundary BL") between the pad main body 50 and the hard pad portion 60 in the pad thickness direction TD is shown by a two-dot chain line. As shown in FIG. 4A, the hard pad portion 60 has a step surface 65 exposed to the pad front side F in the pad thickness direction TD at the position of the boundary BL. The step surface 65 forms a part of the ventilation path 2. In other words, the step surface 65 faces the ventilation path 2. Also, as shown in FIG. 5A, the step surface 65 is formed over the entire area around the outer edge 61a of the second ventilation opening 61 located at the boundary BL. In other words, in a plan view of the cushion pad 10 seen from the pad front side F toward the pad back side B along the pad thickness direction TD (see FIG. 5A), the entire outer edge of the second ventilation hole 61 is located inside the first ventilation hole 51. Then, as shown in FIGS. 4A and 5A, the inner end of the annular stepped surface 65 is continuous with the outer edge 61a of the second ventilation hole 61. Also, the outer end of the annular stepped surface 65 is continuous with the outer edge 51a of the first ventilation hole 51. By configuring the seat pad 1 in this manner, in the manufacturing process of the seat pad 1, the second ventilation hole 61 of the hard pad portion 60 can be blocked by the convex portion 250L (see FIG. 6, etc.) of the lower mold 200L of the seat pad molding mold 200 (see FIG. 6, etc.) described later, and the material forming the pad main body portion 50 can be prevented from entering between the hard pad portion 60 and the convex portion 250U of the upper mold 200U of the seat pad molding mold 200 described later, and between the paired convex portions 250U, 250L. The details of this will be described later (see FIG. 10, etc.).

[0038] As shown in FIG. 2 and FIG. 5A, the cross-sectional shape of the first ventilation opening 51 and the second ventilation opening 61 in this embodiment perpendicular to the pad thickness direction TD is a circle. The first ventilation opening 51 and the second ventilation opening 61 in this embodiment are arranged in a concentric shape in a plan view of the cushion pad 10 along the pad thickness direction TD. FIG. 5B shows another configuration example of the ventilation path 2 shown in FIG. 5A. As shown in FIG. 5B, the cross-sectional shape of the first ventilation opening 51 and the second ventilation opening 61 perpendicular to the pad thickness direction TD may be an ellipse. However, the cross-sectional shape of the first ventilation opening 51 and the second ventilation opening 61 perpendicular to the pad thickness direction TD is not limited to a circle or an ellipse, and may be, for example, a polygonal shape, an ellipse, or the like. In addition, the cross-sectional shapes of the first ventilation opening 51 and the second ventilation opening 61 perpendicular to the pad thickness direction TD may be different from each other.

[0039] The distance d (see FIGS. 5A and 5B) between the outer edge 51a of the first ventilation hole 51 and the outer edge 61a of the second ventilation hole 61 in a plan view is set in consideration of the degree of blocking of the second ventilation hole 61 required in the manufacturing process, and may be, for example, 1 to 5 mm, but is not particularly limited. Here, the above-mentioned "distance d" refers to the width of the step surface 65.

[0040] 4B and 4C show other configuration examples of the first ventilation opening 51 and the second ventilation opening 61 shown in FIG. 4A, respectively. As shown in FIG. 4B, the first ventilation opening 51 may be configured such that the cross-sectional area perpendicular to the pad thickness direction TD gradually increases from the end of the pad back side B to the end of the pad front side F in the pad thickness direction TD. This reduces the resistance generated when air passes through the air passage 2, and improves the efficiency of suction / discharge of air by the fan 110. In the example shown in FIG. 4B, the shape of the first ventilation opening 51 is tapered (frustum cone-shaped) expanding toward the pad front side F, so that the cross-sectional area perpendicular to the pad thickness direction TD of the first ventilation opening 51 gradually increases from the end of the pad back side B to the end of the pad front side F in the pad thickness direction TD. When the first ventilation hole 51 is tapered (frustum-shaped) with a diameter expanding toward the pad front side F, the gradient formed by a virtual line parallel to the pad thickness direction TD and an outline of the first ventilation hole 51 when viewed in cross section in the pad thickness direction TD may be, for example, 1 to 2 degrees, but is not particularly limited. The first ventilation hole 51 may have a shape other than tapered (frustum-shaped) such that the cross-sectional area perpendicular to the pad thickness direction TD gradually increases from the end of the pad back side B toward the end of the pad front side F in the pad thickness direction TD.

[0041] As shown in FIG. 4A and FIG. 4B, an inside corner 70 is formed in the air passage 2. The inside corner 70 is formed by the pad main body 50 and the hard pad 60. More specifically, the inside corner 70 is formed by the inner peripheral surface that defines the first air hole 51 of the pad main body 50 and the annular step surface 65 of the hard pad 60. The inside corner 70 forms a part of the air passage 2. In other words, the inside corner 70 faces the air passage 2. As shown in FIG. 4A and FIG. 4B, the cross-sectional shape of the inside corner 70 in the pad thickness direction TD may be a shape in which a sharp apex is formed at the position where two straight lines intersect. However, the cross-sectional shape of the inside corner 70 in the pad thickness direction TD is preferably a polygonal shape in which multiple straight lines are continuous so that a sharp apex is not formed, and more preferably a circular arc shape as shown in FIG. 4C. In this way, air is less likely to stagnate in the inside corner 70, compared to the shape of the inside corner 70 shown in Figures 4A and 4B. Therefore, by making the cross-sectional shape of the inside corner 70 in the pad thickness direction TD polygonal or arc-shaped, the resistance generated when air passes through the air passage 2 can be reduced, and the efficiency of suction / discharge of air by the fan 110 can be improved, compared to the shape of the inside corner 70 shown in Figures 4A and 4B. When the cross-sectional shape of the inside corner 70 in the pad thickness direction TD is polygonal or arc-shaped, the radius R of the circumscribing circle or the arc itself can be, for example, 0.25 to 1.25 mm, but is not particularly limited.

[0042] Next, a seat pad molding die 200 used for manufacturing the cushion pad 10 as the seat pad 1 according to the above-mentioned embodiment will be described. FIG. 6 is a diagram showing a cross section of the seat pad molding die 200 in the left-right direction. As shown in FIG. 6, the seat pad molding die 200 includes an upper die 200U and a lower die 200L arranged vertically below the upper die 200U. The upper die 200U of this embodiment includes an upper die molding surface US configured to mold the back surface BS of the cushion pad 10. The lower die 200L of this embodiment includes a lower die molding surface LS configured to mold the front surface FS of the cushion pad 10.

[0043] As shown in Fig. 6, the lower mold forming surface LS includes a main pad portion forming surface 211s configured to form a surface FS of the main pad portion 11 of the cushion pad 10, and a pair of side pad portion forming surfaces 212s located on both the left and right sides of the main pad portion forming surface 211s and configured to form surfaces FS of a pair of side pad portions 12 of the cushion pad 10. The lower mold forming surface LS also includes a back pad facing portion forming surface located on the rear side of the main pad portion forming surface 211s and configured to form a surface FS of the back pad facing portion 13 of the cushion pad 10. The main pad portion forming surface 211s includes a lower thigh forming surface configured to form a surface FS of the lower thigh portion 11t of the cushion pad 10, and a lower buttocks forming surface 211hs (see Fig. 6) located on the rear side of the lower thigh forming surface and configured to form a surface FS of the lower buttocks portion 11h of the cushion pad 10. Further, the upper mold 200U of the seat pad molding die 200 of this embodiment is provided with a convex portion 255 that is configured so as to be insertable into the air flow path 62 of the hard pad portion 60 of the seat pad 1.

[0044] The upper mold 200U and the lower mold 200L of the seat pad forming mold 200 are provided with a plurality of pairs of protruding portions 250U, 250L having opposing surfaces 250Us, 250Ls at their tips that face each other.

[0045] The protrusion 250U of the upper die 200U is formed on the upper die molding surface US. The protrusion 250U of the upper die 200U is configured so as to be insertable into the second ventilation hole 61 of the hard pad portion 60. The protrusion 250U is inserted into the second ventilation hole 61 of the hard pad portion 60 during the manufacturing process of the seat pad 1. By being inserted into the second ventilation hole 61 of the hard pad portion 60, the protrusion 250U has the effect of positioning the hard pad portion 60 with respect to the upper die 200U.

[0046] The protrusion 250L of the lower die 200L is formed on the lower die molding surface LS. The protrusion 250L of the lower die 200L is configured to mold the first ventilation hole 51 of the pad main body 50.

[0047] 7A shows an enlarged view of the periphery of the pair of convex parts 250U, 250L of the upper mold 200U and the lower mold 200L of the sheet pad molding mold 200 shown in FIG. 6. FIG. 7B shows the state in which the upper mold 200U and the lower mold 200L are closed from the state of FIG. 7A. As shown in FIG. 7B, the opposing surfaces 250Us, 250Ls of the pair of convex parts 250U, 250L of the upper mold 200U and the lower mold 200L of this embodiment are configured to abut against each other when the upper mold 200U and the lower mold 200L are closed. By configuring the opposing surfaces 250Us, 250Ls in this way, it is possible to prevent the formation material of the pad main body 50 from entering between the opposing surfaces 250Us, 250Ls during the manufacturing process of the sheet pad 1. As described later, since the second ventilation hole 61 of the hard pad portion 60 attached to the upper mold 200U is blocked by the opposing surface 250Ls of the protrusion 250L of the lower mold 200L, the opposing surfaces 250Us, 250Ls do not have to abut against each other when the upper mold 200U and the lower mold 200L are closed. In other words, the opposing surfaces 250Us, 250Ls may be configured to have a gap between them when the upper mold 200U and the lower mold 200L are closed.

[0048] As shown in FIG. 7B, the facing surface 250Ls of the convex portion 250L of the lower mold 200L includes an overlapping surface 250Ls1 that overlaps the facing surface 250Us of the convex portion 250U of the upper mold 200U in a plan view when the upper mold 200U and the lower mold 200L are closed, and a non-overlapping surface 250Ls2 that does not overlap the facing surface 250Us of the convex portion 250U of the upper mold 200U in a plan view. Here, "plan view" means a plan view seen along the pad thickness direction TD of the sheet pad 1 (see FIG. 3, etc.) molded by the sheet pad molding mold 200. FIG. 8 is a cross-sectional view taken along the line CC in FIG. 7B. In FIG. 8, the outer edge 251 of the overlapping surface 250Ls1 of the facing surface 250Ls of the convex portion 250L of the lower mold 200L is indicated by a two-dot chain line. 8, the non-overlapping surface 250Ls2 surrounds the entire outer edge 251 of the overlapping surface 250Ls1. By configuring the opposing surface 250Ls in this manner, the second ventilation hole 61 of the hard pad portion 60 can be blocked by the opposing surface 250Ls of the protruding portion 250L of the lower mold 200L during the manufacturing process of the seat pad 1, and the material forming the pad main body portion 50 can be prevented from entering between the hard pad portion 60 and the protruding portion 250U and between the paired protruding portions 250U and 250L.

[0049] The distance e (see Figure 8) between the outer edge 251 of the overlapping surface 250Ls1 and the outer edge 252 of the non-overlapping surface 250Ls2 in a planar view is determined by calculating backwards from the set value of the distance d (see Figures 5A and 5B) of the seat pad 1, and may be, for example, 1 to 5 mm, but is not particularly limited.

[0050] Next, a method for manufacturing the cushion pad 10 as the seat pad 1 according to the above-mentioned embodiment using the seat pad molding die 200 according to the above-mentioned embodiment will be described. The manufacturing method for the cushion pad 10 as the seat pad 1 of this embodiment includes a preparation step, a mold clamping step, a foam molding step, and a demolding step.

[0051] <Preparation steps> First, in a preparation step, the hard pad portion 60 is placed on the upper die 200U of the seat pad molding die 200 (see FIG. 9A). At this time, by inserting the convex portion 250U of the upper die 200U into the second ventilation hole 61 of the hard pad portion 60, the hard pad portion 60 can be positioned with respect to the upper die 200U and the hard pad portion 60 can be prevented from falling off the upper die 200U. Also, in the preparation step, in parallel with the above-mentioned placing of the hard pad portion 60 on the upper die 200U, a liquid foaming resin material 50' is injected into the lower die molding surface LS of the lower die 200L (see FIG. 9A).

[0052] <Mold clamping step> After the preparation step, the upper mold 200U and the lower mold 200L are closed in the mold clamping step (see FIG. 9B). In this embodiment, the mold clamping step is performed after the foaming resin material 50' is injected into the lower mold molding surface LS of the lower mold 200L in the preparation step, but after the mold clamping step, the liquid foaming resin material 50' may be injected into the lower mold molding surface LS of the lower mold 200L through an injection port provided in the upper mold 200U or the lower mold 200L.

[0053] <Foam molding step> After the mold clamping step, the pad main body 50 is foam-molded in the foam molding step (see FIG. 9C). More specifically, in the foam molding step, the foaming resin material 50' injected into the lower mold molding surface LS of the lower mold 200L is heated at a predetermined temperature for a predetermined time. This causes the foaming resin material 50' injected into the lower mold molding surface LS of the lower mold 200L to gradually expand and fill the cavity of the seat pad molding mold 200. As a result, the pad main body 50 is molded so as to be integrated with the hard pad portion 60. In the foam molding step, the upper mold 200U and the lower mold 200L are maintained in a closed state.

[0054] As described above, in the foam molding step, the foaming resin material 50' injected into the lower mold molding surface LS of the lower mold 200L gradually expands and fills the cavity of the seat pad molding mold 200. At this time, the material for forming the pad main body 50 may enter an unintended place in the seat pad molding mold 200. The unintended place in the seat pad molding mold 200 is specifically the place where the air passage 2 is formed, for example, between the convex part 250U of the upper mold 200U and the hard pad part 60, between the pair of convex parts 250U and 250L of the upper mold 200U and the lower mold 200L, etc. If the material for forming the pad main body 50 enters an unintended place like this, an extra work of removing the excess material for forming the pad main body 50 from the seat pad 1 may occur after the demolding step, which is not preferable. On the other hand, in the foam molding step of this embodiment, the opposing surfaces 250Us, 250Ls of the paired convex portions 250U, 250L of the upper mold 200U and the lower mold 200L abut against each other, thereby preventing the material forming the pad main body portion 50 from entering between the opposing surfaces 250Us, 250Ls in the foam molding step.

[0055] FIG. 10 shows an enlarged view of the pair of convex parts 250U, 250L of the upper mold 200U and the lower mold 200L in the foam molding step. FIG. 11 is a cross-sectional view taken along the line dd in FIG. 10. As shown in FIG. 10 and FIG. 11, in the foam molding step, the opposing surface 250Ls of the convex part 250L of the lower mold 200L has an abutment surface 260Ls2 that abuts against the hard pad part 60 and a non-abutment surface 260Ls1 that does not abut against the hard pad part 60. The abutment surface 260Ls2 of the opposing surface 250Ls is a portion that substantially coincides with the above-mentioned non-overlapping surface 250Ls2 (see FIG. 7B and FIG. 8). The non-abutment surface 260Ls1 of the opposing surface 250Ls is a portion that substantially coincides with the above-mentioned overlapping surface 250Ls1 (see FIG. 7B and FIG. 8). In FIG. 11, the outer edge 261 of the contact surface 260Ls1 is indicated by a two-dot chain line. As shown in FIG. 11, in the foam molding step, the contact surface 260Ls2 surrounds the entire area around the outer edge 261 of the non-contact surface 260Ls1. Therefore, in the foam molding step, the contact surface 260Ls2 contacts the edge of the second ventilation hole 61 so as to cover the second ventilation hole 61 of the hard pad portion 60. Thereby, in the foam molding step, the second ventilation hole 61 of the hard pad portion 60 can be blocked by the opposing surface 250Ls of the convex portion 250L of the lower mold 200L. As a result, in the foam molding step, the material forming the pad main body portion 50 can be prevented from entering between the hard pad portion 60 and the convex portion 250U and between the pair of convex portions 250U and 250L.

[0056] That is, according to the manufacturing method of the seat pad of the present disclosure, the second ventilation hole 61 is blocked by the protrusion 250L of the lower mold 200L, so that the operation of removing excess material for forming the pad main body 50 from the seat pad 1 can be suppressed, and the seat pad 1 can be easily manufactured. Furthermore, in the manufacturing method of the seat pad of this embodiment, the opposing surfaces 250Us and 250Ls abut against each other, so that the material for forming the pad main body 50 can be further suppressed from entering between the opposing surfaces 250Us and 250Ls. Therefore, the operation of removing excess material for forming the pad main body 50 from the seat pad 1 can be further suppressed.

[0057] The interval f (see FIG. 11) between the outer edge 261 of the non-contact surface 260Ls1 and the outer edge 262 of the contact surface 260Ls2 in a plan view may be, for example, 1 to 5 mm, but is not particularly limited. However, by making the interval f 1 mm or more, the second ventilation hole 61 of the hard pad portion 60 can be more reliably blocked by the convex portion 250L of the lower mold 200L in the foam molding step than when the interval f is less than 1 mm, and the material forming the pad main body portion 50 can be more effectively prevented from entering between the hard pad portion 60 and the convex portion 250U and between the pair of convex portions 250U and 250L. On the other hand, if the interval f is too large, the interval d (see FIG. 5A and FIG. 5B) of the seat pad 1 molded by the manufacturing method for the seat pad of the present disclosure becomes large, and as a result, air is likely to remain in the recessed corner portion 70 (see FIG. 4A, etc.), which may reduce the efficiency of suction / exhaust of air by the fan 110, which is not preferable.

[0058] <Mold removal step> After the foam molding step, in a demolding step, the pad body portion 50 and the hard pad portion 60 which are integrally molded are demolded from the seat pad molding mold 200.

[0059] The seat pad, seat pad mold, and seat pad manufacturing method according to the present disclosure are not limited to the specific configurations shown in the above-described embodiments and modified examples, and various modifications, changes, and combinations are possible without departing from the scope of the claims. [Industrial Applicability]

[0060] The present disclosure relates to a seat pad, a seat pad mold, and a method for manufacturing a seat pad. [Explanation of symbols]

[0061] 1: Seat pad 2: Ventilation channel 10: Cushion pad 11: Main pad section 11h: Lower buttocks 11t: Lower thigh 12: Side pad section 13: Back pad facing part 20: Back pad 21: Main pad section 30: Cover material 40: Headrest 50: Pad body 50': Foam resin material 51: First ventilation hole 51a: Outer edge 60: Hard pad section 61: Second ventilation hole 61a:Outer edge 62: Air flow path 63: Recess 65: Step surface 70: Inside corner 80: Lid component 81: Hole 100: Vehicle seats 110: Fan 200: Seat pad molding 200L: Lower mold 200U: Upper mold 211s: Main pad molding surface 211hs: Bottom of the buttocks 212s: Side pad molding surface 250L: Convex part 250Ls: Opposite surface 250Ls1: Overlapping surface 250Ls2: Non-overlapping surface 250U: Convex 250Us: Opposite side 251: Outer edge 252:Outer edge 255: Convex part 260Ls1: Non-contact surface 260Ls2: Contact surface 261: Outer edge 262: Outer edge B: Back side of pad BL: Boundary between the pad body and the hard pad in the thickness direction BS: Back of seat pad F: Pad front side FS: Seat pad surface LS: Lower molding surface R: Radius dimension TD: Thickness direction US: Upper molding surface d:Spacing e:Spacing f:Spacing

Claims

1. A seat pad comprising: a pad main body; and a hard pad portion overlapping a back side of the pad main body and harder than the pad main body, wherein at least one ventilation passage is formed penetrating through the pad main body and the hard pad portion in a pad thickness direction, The ventilation passage includes a first ventilation hole formed in the pad main body portion and a second ventilation hole formed in the hard pad portion, the hard pad portion includes a step surface that forms a part of the air passage and is exposed to a pad front side in the pad thickness direction at a boundary between the pad main body portion and the hard pad portion in the pad thickness direction, The step surface is formed over the entire area around the outer edge of the second air vent located at the boundary.

2. The seat pad according to claim 1 , wherein the first ventilation hole has a cross-sectional area perpendicular to the thickness direction of the pad that gradually increases from an end of the back side of the pad in the thickness direction of the pad to an end of the front side of the pad.

3. 3. The seat pad according to claim 1, wherein a cross-sectional shape in the thickness direction of the pad of an inside corner portion that is formed by the pad main body portion and the hard pad portion and that forms part of the air passage is an arc shape or a polygon shape.

4. A seat pad molding die including an upper die and a lower die disposed below the upper die, the seat pad molding die being configured to integrally mold a pad main body portion and a hard pad portion harder than the pad main body portion, The upper mold and the lower mold each include at least one pair of protrusions having opposing surfaces at their tips, When the upper mold and the lower mold are closed, the opposing surface of the convex portion of the lower mold includes an overlapping surface that overlaps with the opposing surface of the convex portion of the upper mold in a plan view, and a non-overlapping surface that does not overlap with the opposing surface of the convex portion of the upper mold in a plan view, The seat pad mold, wherein the non-overlapping surface surrounds the entire outer edge of the overlapping surface.

5. A method for manufacturing a seat pad, comprising the steps of: using a molding die having an upper die and a lower die disposed below the upper die; forming a pad main body portion and a hard pad portion harder than the pad main body portion in an integrated manner; a foam molding step of covering a molding surface of the upper mold with the hard pad portion and foam molding the pad main body portion in a state where the upper mold and the lower mold are closed, The upper mold and the lower mold each include at least one pair of protrusions having opposing surfaces at their tips, A method for manufacturing a seat pad, wherein, on the opposing surface of the convex portion of the lower mold, a portion that abuts against the hard pad portion is defined as a contact surface, and a portion that does not abut against the hard pad portion is defined as a non-contact surface, in the foam molding step, the abutment surface surrounds the entire outer edge of the non-contact surface.

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