Mold, method for manufacturing molded foam body, and molded foam body

Abstract

A mold that: makes it possible to manufacture a molded foam body wherein a reinforcing member extends to a portion of the outer face of the molded body main body that corresponds to a parting line in the inner face of the cavity of the mold; and prevents molding problems stemming from the reinforcing member getting into the aforementioned parting line. Also: a method for manufacturing a molded foam body using the aforementioned mold; and a molded foam body manufactured thereby. The aforementioned mold (1) is provided with a seal member (7) that seals the space between mating faces (2a, 3a) of mold parts (2, 3) when the mold is fastened, and said seal member (7) is designed so as to be able to seal the space between the mating faces (2a, 3a) even if the reinforcing member (22) gets in between the mating faces (2a, 3a) on the cavity (4) side of the seal member (7).

Claims

1. A manufacturing method for manufacturing a molded foam body including a molded body main body formed from a foamable synthetic resin, and a non-woven fabric reinforcement member disposed across at least a portion of an outer face of the molded body main body and integrated with the molded body main body, the manufacturing method comprising: providing a mold including at least two molding molds, the at least two molding molds being shaped so as to be capable of forming a cavity surrounded by the molding molds by fastening the molding molds together and forming a parting line by joining mating faces of each of the molding molds together at an inner face of the cavity; a non-woven fabric reinforcement member placement process, in which the non-woven fabric reinforcement member is disposed across a cavity inner face of at least one molding mold prior to fastening the mold, and due to such disposition, the non-woven fabric reinforcement member is disposed so as to be adjacent to at least a portion of the parting line inside the cavity; fixing a seal member to one mating face of the mating faces so that the seal member protrudes from the one mating face to another mating face side, so that a seal is made between the mating faces by the seal member pressing against the other mating face during mold fastening; forming a region of the mold between the mating faces from the cavity inner face to the seal member to form a region for trapping the non-woven fabric reinforcement member; forming a recessed step portion facing inside the cavity on the mating face of the molding mold that is opposite to the molding mold at which the reinforcement member is disposed, wherein the recessed step portion is formed corresponding to a size of the non-woven fabric reinforcement member, and is shaped such that the non-woven fabric reinforcement member is able to escape inside the recessed step portion in a case in which the non-woven fabric reinforcement member enters between the mating faces during mold fastening; forming the cavity surrounded by the molding molds by fastening the molding molds together, and forming the parting line by joining mating faces of each of the molding molds together at an inner face of the cavity; and a foam molding process, in which after the non-woven fabric reinforcement member placement process, the foamable synthetic resin is foamed inside the cavity, wherein the seal member is disposed more to an opposite side from a cavity side than the recessed step portion, and wherein a basis weight of the non-woven fabric is from 0.05 kg/m.sup.2 to 0.1 kg/m.sup.2 and a projection height T of the seal member from the one mating face is from 0.2 mm to 0.8 mm, or the basis weight of the non-woven fabric is from 0.1 kg/m.sup.2 to 0.2 kg/m.sup.2 and the projection height T is from 0.8 mm to 1.5 mm prior to mold fastening.

2. The manufacturing method for a molded foam body of claim 1, wherein: in the non-woven fabric reinforcement member placement process, the non-woven fabric reinforcement member is disposed such that an outer peripheral edge of the non-woven fabric reinforcement member contacts the parting line, or such that a spacing between the outer peripheral edge of the reinforcement member and the parting line is 5 mm or less.

3. A molded foam body including a molded body main body formed from a foamable synthetic resin, and a reinforcement member disposed across at least a portion of an outer face of the molded body main body and integrated with the molded body main body, wherein: the molded foam body is manufactured by the manufacturing method for a molded foam body of claim 1.

4. The molded foam body of claim 3, wherein the molded foam body is a seat pad.

5. A mold for manufacturing a molded foam body including a molded body main body comprising a foamable synthetic resin, and a reinforcement member disposed across at least a portion of an outer face of the molded body main body and integrated with the molded body main body, wherein: the mold includes at least two molding molds, a cavity surrounded by the molding molds is formed by fastening the molding molds together, and a parting line is formed by joining mating faces of each of the molding molds together at an inner face of the cavity; the mold includes a seal member that is fixed to one of the molding molds and seals between the mating faces during mold fastening; when manufacturing the molded foam body, the reinforcement member that comprises a non-woven fabric is disposed across a cavity inner face of the molding mold to which the seal member is fixed prior to fastening the mold, and due to such placement, to be disposed inside the cavity so as to be adjacent to at least a portion of the parting line; a region of the mold between the mating faces from the cavity inner face to the seal member forms a region for trapping the reinforcement member; the seal member is attached to one mating face of the mating faces and protrudes from the one mating face to another mating face side prior to mold fastening, such that a seal is made between the mating faces by the seal member pressing against the other mating face during mold fastening; wherein a basis weight of the non-woven fabric is from 0.05 kg/m.sup.2 to 0.1 kg/m.sup.2, and a projection height T of the seal member from the one mating face is from 0.2 mm to 0.8 mm, or the basis weight of the non-woven fabric is from 0.1 kg/m.sup.2 to 0.2 kg/m.sup.2, and the projection height T is from 0.8 mm to 1.5 mm prior to mold fastening; a recessed step portion facing inside the cavity is provided on the mating face of the molding mold that is opposite to the molding mold at which the reinforcement member is disposed, where at least a portion of the parting line is disposed adjacent to the reinforcement member; the recessed step portion is formed corresponding to a size of the reinforcement member, and is configured such that the reinforcement member is able to escape inside the recessed step portion in a case in which the reinforcement member enters between the mating faces during mold fastening; and the seal member is disposed more to an opposite side from a cavity side than the recessed step portion.

6. The mold of claim 5, wherein the recessed step portion is opened toward inside the cavity.

7. The mold of claim 5, wherein the seal member is provided around an entire periphery of the parting line.

8. The mold of claim 5, wherein a distance from the inner face of the cavity to the seal member is from 1 mm to 10 mm where at least a portion of the parting line is disposed adjacent to the reinforcement member.

9. The mold of claim 5, wherein the seal member comprises an elastic material.

10. The mold of claim 5, wherein an outer peripheral edge of the reinforcement member is disposed so as to be aligned with the parting line around an entire periphery.

11. The mold of claim 5, wherein the recessed step portion is arranged to be in parallel with and along the parting line.

12. The mold of claim 5, wherein the basis weight of the non-woven fabric is from 0.05 kg/m.sup.2 to 0.1 kg/m.sup.2, and a depth of the recessed step portion is from 0.3 mm to 0.4 mm, or the basis weight of the non-woven fabric is from 0.1 kg/m.sup.2 to 0.2 kg/m.sup.2, and the depth is from 0.4 mm to 0.6 mm.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) FIG. 1 is a cross-section view of a mold according to a first exemplary embodiment.

(2) FIG. 2 is an enlarged cross-section view of portion II in FIG. 1.

(3) FIG. 3 is a plan view of a lower mold of the mold in FIG. 1.

(4) FIG. 4a is a back face view and FIG. 4b is a cross-section view of a seat pad as a molded foam body manufactured using the mold in FIG. 1.

(5) FIGS. 5a, 5b are enlarged cross-section views of the same portion as in FIG. 2 in a case in which a reinforcement member has entered a parting line of the mold in FIG. 1.

(6) FIG. 6a is a back face view and FIG. 6b is a plan view of a lower mold illustrated in a second exemplary embodiment.

(7) FIGS. 7a, 7b are enlarged cross-section views of the same portion as in FIG. 2 of a mold according to a third exemplary embodiment.

(8) FIG. 8 is a plan view of a lower mold of the mold in FIGS. 7a, 7b.

(9) FIG. 9 is a rear face view of a seat pad and a plan view of a lower mold illustrating a fourth exemplary embodiment.

(10) FIG. 10 is a cross-section view of a seat pad according to a conventional example.

(11) FIG. 11 is a cross-section view of a seat pad manufacturing mold according to a conventional example.

DESCRIPTION OF EMBODIMENTS

(12) Explanation follows regarding exemplary embodiments, with reference to the drawings. Note that, although the following exemplary embodiments illustrate examples of application of the present invention to a mold for manufacturing a seat pad, and to a manufacturing method of a seat pad using the mold, the present invention is also applicable to a mold for manufacturing a molded foam body other than a seat pad, and to a manufacturing method for a molded foam body using the mold.

First Exemplary Embodiment

(13) FIG. 1 is a cross-section view of a mold according to a first exemplary embodiment. FIG. 2 is an enlarged cross-section view of section II in FIG. 1. FIG. 3 is a plan view of a lower mold of the mold. FIG. 4a is a back face view of a seat pad as a molded foam body manufactured using the mold, and FIG. 4b is a cross-section view taken along line IVB-IVB in FIG. 4a. FIG. 5a and FIG. 5b are enlarged cross-section views of the same portion as illustrated in FIG. 2, in a case in which a reinforcement member has entered a parting line of the mold. FIG. 5a illustrates a state before mold fastening, and FIG. 5b illustrates a state after mold fastening.

(14) In the present exemplary embodiment, a mold 1 serves to manufacture a seat pad 20 configuring a vehicle seat. Note that, although in the exemplary embodiment the seat pad 20 is a cushion pad configuring a seat section of a vehicle seat, the present invention is also applicable to a back pad configuring a backrest section of a vehicle seat. FIG. 1 illustrates a vertical cross-section along the left-right direction of the seat pad (cushion pad) 20 during use.

(15) The seat pad 20 includes a seat pad main body 21 as a molded body main body comprising a foamable synthetic resin, such as polyurethane foam, and a reinforcement member 22 that is disposed across a back face of the seat pad main body 21 (the lower face of the seat pad main body 21 during use, since the seat pad 20 is a cushion pad in the exemplary embodiment) and integrated with the seat pad main body 21.

(16) The reinforcement member 22 is disposed up to substantially the terminal end of the outer peripheral side of the back face of the seat pad main body 21. In the exemplary embodiment, as illustrated in FIGS. 4a, 4b, the reinforcement member 22 is configured in a shape covering substantially the entire back face of the seat pad main body 21, and the outer peripheral edge of the reinforcement member 22 is disposed so as to be aligned with the terminal end of the outer peripheral side of the back face of the seat pad main body 21 around the entire periphery. In the exemplary embodiment, a parting line P is present on the inner face of a cavity 4 of the mold 1, described below, at a position corresponding to the terminal end of the outer peripheral side of the back face of the seat pad main body 21. In the exemplary embodiment, the reinforcement member 22 is formed from an air permeable material. A non-woven fabric or the like is suitably applied as the air permeable material.

(17) Note that the shape, disposition, configuration material, and the like of the reinforcement member 22 are not limited thereto. For example, the reinforcement member 22 may be configured in a shape so as to cover a portion of the back face of the seat pad main body 21, and a portion of the outer peripheral edge of the reinforcement member 22 may be disposed so as to be aligned with an portion of the outer peripheral side terminal end of the back face of the seat pad main body 21. The reinforcement member 22 may be disposed at a region of the outer face of the seat pad main body 21 other than the back face of the seat pad main body 21. The reinforcement member 22 may be disposed straddled across two or more faces out of the back face, side peripheral faces, and a seating face of the seat pad main body 21. The reinforcement member 22 may be configured of a material other than a non-woven fabric. An air permeable member may be disposed to the reinforcement member 22 at a region overlapping with exhaust holes 5 of the mold 1, described later.

(18) In the present invention, the reinforcement member 22 is disposed up to substantially the terminal end (=the position on the seat pad main body 21 outer face corresponding to the parting line P of the inner face of the cavity 4 of the mold 1, described later) of the outer peripheral side of the back face of the seat pad main body 21 indicates that, within a pre-set acceptable range of attachment error, the outer peripheral edge of the reinforcement member 22 may be positioned further to the center side of the back face than the outer peripheral side terminal end of the back face of the seat pad main body 21, or may protrude out from the outer peripheral side terminal end of the back face toward the sides of the seat pad main body 21.

(19) In the exemplary embodiment, as illustrated in FIG. 1, the mold 1 includes an upper mold 2 and a lower mold 3, and exhaust holes 5 for discharging gas inside the cavity 4 surrounded by the upper mold 2 and the lower mold 3, to outside the cavity 4. Note that the mold 1 may also include a mold core (not illustrated in the drawings). In the exemplary embodiment, the upper mold 2 and the lower mold 3 are both equivalent to the molding molds of the first aspect. The upper mold 2 and the lower mold 3 mate together at respective peripheral edge portions. The symbol P indicates the parting line formed by joining together mating faces 2a, 3a (FIGS. 2, 3, 5a, 5b) of the peripheral edge portions of the upper mold 2 and the lower mold 3.

(20) In the exemplary embodiment, the exhaust holes 5 are provided further to the center side of a cavity inner face 2b of the upper mold 2 than the parting line P. The exhaust holes 5 are disposed at portions of the cavity inner face 2b of the upper mold 2 where it is difficult to remove gas from the parting line P alone during foam molding, such as a portion at a higher position than the parting line P, or a portion where a location lower than the parting line P exists between the portion and the parting line P. FIG. 1 illustrates two exhaust holes 5 disposed at a spacing in the seat pad left-right direction; however the quantity and placement of the exhaust holes 5 are not limited thereto. Note that the exhaust holes 5 may also be disposed to the lower mold 3, or the like, if required.

(21) The seat pad 20 (the seat pad main body 21) is molded in the cavity 4 of the mold 1 with the seating face facing downward. Namely, the seating face and side peripheral faces of the seat pad 20 are molded by a cavity inner face 3b of the lower mold 3, and the back face of the seat pad 20 is molded by the cavity inner face 2b of the upper mold 2. The parting line P is positioned at a boundary portion of the back face and the side peripheral faces of the seat pad 20, namely, at the outer peripheral side terminal end of the back face of the seat pad 20. Note that placement of the parting line P is not limited thereto, and may be disposed at a position corresponding to a location other than the outer peripheral side terminal end of the back face of the seat pad main body 21. Prior to the foam molding process of the seat pad 20, the reinforcement member 22 is disposed across the cavity inner face 2b of the upper mold 2, and the reinforcement member 22 is fixed to the upper mold 2 by a fixing (not illustrated in the drawings) such as pins or magnets. The outer peripheral edge of the reinforcement member 22 is disposed so as to be substantially aligned with the parting line P around the entire periphery when this placement is performed

(22) In the present invention, the outer peripheral edge of the reinforcement member 22 is disposed so as to be substantially aligned with the parting line P around the entire periphery indicates that, when attaching the reinforcement member 22 to the cavity inner face 2b of the upper mold 2, within the pre-set acceptable range of attachment error, the outer peripheral edge of the reinforcement member 22 may be positioned further to the center side of the cavity inner face 2b than a boundary portion Bd.sub.1 between the cavity inner face 2b and the mating face 2a of the upper mold 2, or may protrude out from the boundary portion Bd.sub.1 to the mating face 2a side (or, with the mold 1 in a fastened state, the peripheral edge portion of the reinforcement member 22 may cross the parting line P and overlap with the cavity inner face 3b of the lower mold 3).

(23) As illustrated in FIG. 2 and FIG. 5b, when the mold 1 has been fastened, a boundary portion Bd.sub.2 between the mating face 3a and the cavity inner face 3b of the lower mold 3, overlaps on the extension direction of the mating faces 2a, 3a with the boundary portion Bd.sub.1 between the mating face 2a and the cavity inner face 2b of the upper mold 2. Note that the respective boundary portions Bd.sub.1, Bd.sub.2 may be offset in the extension direction of the mating faces 2a, 3a when the mold 1 is in a fastened state.

(24) A seal member 7 is provided to the mold 1 in order to seal between the mating faces 2a, 3a of the upper mold 2 and the lower mold 3. The seal member 7 is configured by an elastic material such as rubber. Silicon rubber, fluorine rubber, nitrile rubber, or the like is suitable as the seal member 7; however configuration is not limited thereto.

(25) In the exemplary embodiment, a seal member attachment groove 2c is provided to the mating face 2a of the upper mold 2, and a base end side (the upper end side in FIGS. 2, 5a, 5b) of the seal member 7 is fixed to the upper mold 2 by fitting into the seal member attachment groove 2c. In the exemplary embodiment, the seal member 7 is provided around the entire periphery of the mating face 2a of the upper mold 2. As illustrated in FIG. 5a, when the upper mold 2 and the lower mold 3 are in an opened state, a leading end side (the lower end side in FIG. 2, and FIGS. 5a, 5b) of the seal member 7 is in a state protruding from the mating face 2a of the upper mold 2 toward the lower mold 3 side. During mold fastening, the leading end side of the seal member 7 is pressed against the mating face 3a of the lower mold 3, and elastic close contact of the seal member 7 seals between the mating face 2a (the inner face of the seal member attachment groove 2c) of the upper mold 2 and the mating face 3a of the lower mold 3.

(26) As illustrated in FIG. 5b, the seal member 7 is configured so as to be capable of sufficiently sealing between the mating faces 2a, 3a, even suppose the reinforcement member 22 enters the parting line P during mold fastening and becomes trapped between the mating faces 2a, 3a more to the cavity 4 side than the seal member 7. Namely, a region of the mold 1 between the mating faces 2a, 3a from the cavity 4 inner face (boundary portions Bd.sub.1, Bd.sub.2) to the seal member 7 forms an acceptable region for trapping the reinforcement member, that allows the reinforcement member 22 to become trapped between the mating faces 2a, 3a during mold fastening, and is capable of sufficiently sealing between the mating faces 2a, 3a, even with the reinforcement member 22 trapped in between.

(27) A distance W.sub.1 (FIG. 2) from the inner face of the cavity 4 to the seal member 7 (namely, the width of the acceptable region for trapping the reinforcement member) is suitably set corresponding to the acceptable range of attachment error of the reinforcement member 22, pre-set for the seat pad 20 manufactured using the mold 1. For example, in order to configure the seat pad 20 as a common, ordinary vehicle seat, the acceptable range of attachment error of the reinforcement member 22 is approximately from 0 mm to 5 mm. In such cases, the distance W.sub.1 from the inner face of the cavity 4 to the seal member 7 is preferably from 1 mm to 10 mm, and particularly preferably from 5 mm to 10 mm.

(28) An projection height T of the seal member 7 from the mating face 2a with the mold in an opened state (FIG. 5a; hereafter simply referred to as projection height T) is suitably set according to the thickness of the reinforcement member 22 used in the seat pad 20. Note that, since it is generally difficult to unambiguously derive the thickness of the reinforcement member 22 by actual measurement when a fabric material, such as a non-woven fabric, is used as the configuration material for the reinforcement member 22, the projection height T is preferably set according to the basis weight of the fabric material. Specifically, in cases in which the reinforcement member 22 is configured by a non-woven fabric, for example, when the basis weight of the non-woven fabric is from 0.05 kg/m.sup.2 to 0.1 kg/m.sup.2, the projection height T is preferably from 0.2 mm to 1.5 mm and particularly preferably from 0.5 mm to 0.8 mm, and when the basis weight of the non-woven fabric is from 0.1 kg/m.sup.2 to 0.2 kg/m.sup.2, the projection height T is preferably from 0.5 mm to 1.5 mm and particularly preferably from 0.8 mm to 1.2 mm.

(29) Note that, although in the exemplary embodiment the seal member 7 is provided to the mating face 2a of the upper mold 2, the seal member 7 may be provided to the mating face 3a of the lower mold 3, or may be provided to both the mating faces 2a, 3a of the upper mold 2 and the lower mold 3, respectively.

(30) Explanation follows regarding a procedure for manufacturing the seat pad 20 using the mold 1.

(31) First, the upper mold 2 and the lower mold 3 are opened, the reinforcement member 22 is disposed across the cavity inner face 2b of the upper mold 2, and the reinforcement member 22 is fixed to the upper mold 2 by the fixing (a reinforcement placement process). In the exemplary embodiment, the reinforcement member 22 is disposed so as to cover the entire cavity inner face 2b of the upper mold 2, and the outer peripheral edge of the reinforcement member 22 is aligned around the entire periphery with the parting line P (the boundary portion Bd.sub.1 between the cavity inner face 2b and the mating face 2a of the upper mold 2).

(32) Next, foamable synthetic resin raw material is poured into the lower mold 3, the lower mold 3 and the upper mold 2 are fastened, and the raw material is foamed (a foam molding process). A foamed synthetic resin formed from the foamable raw material fills inside the cavity 4. When this placement is performed, gas inside the cavity 4 permeates through the reinforcement member 22 formed from an air permeable material, and is discharged from the cavity 4 through the exhaust holes 5. The seat pad main body 21 is formed, and the seat pad main body 21 and the reinforcement member 22 are integrated together by the foamable synthetic resin filling inside the cavity 4. After the foamed synthetic resin has cured, the mold is opened and removed. The seat pad 20 is then completed by surface finishing treatment of the seat pad 20, if required.

(33) In the mold 1, the seal member 7 seals between the mating faces 2a, 3a during mold fastening. Suppose the reinforcement member 22 becomes trapped between the mating faces 2a, 3a more to the cavity 4 side than the seal member 7 during mold fastening, configuration is such that the seal member 7 is able to seal between the mating faces 2a, 3a. This enables molding defects of the seat pad main body 21 caused by the reinforcement member becoming trapped in the parting line P to be reliably prevented. This accordingly enables manufacture of the seat pad 20 disposed with the reinforcement member 22 up to a position on the seat pad main body 21 outer face corresponding to the parting line P of the cavity 4 inner face of the mold 1, without occurrence of molding defects of the seat pad main body 21.

(34) In the exemplary embodiment, the seal member 7 is provided around the entire periphery of the parting line P, thereby enabling sufficient sealing between the mating faces 2a, 3a by the seal member 7 around the entire periphery of the parting line P during mold fastening.

(35) As previously described, since the acceptable range of attachment error of the reinforcement member 22 is approximately from 0 mm to 5 mm for a seat pad 20 used in an ordinary vehicle seat, by setting the distance W.sub.1 from the inner face of the cavity 4 to the seal member 7 from 1 mm to 10 mm, and preferably from 5 mm to 10 mm, as in the exemplary embodiment, molding defects of the seat pad main body 21 caused by the reinforcement member 22 becoming trapped in the parting line P can be more reliably prevented, even when there is attachment error of the reinforcement member 22 within the acceptable range.

(36) In the exemplary embodiment, the reinforcement member 22 is configured from a non-woven fabric, and the projection height T of the seal member 7 from the mating face 2a with the mold is an opened state is suitably set according to the basis weight of the non-woven fabric. Namely, when the basis weight of the non-woven fabric is from 0.05 kg/m.sup.2 to 0.1 kg/m.sup.2, the projection height T is preferably from 0.2 mm to 0.8 mm, and when the basis weight of the non-woven fabric is from 0.1 kg/m.sup.2 to 0.2 kg/m.sup.2, the projection height T is preferably from 0.8 mm to 1.5 mm. With such a configuration, the seal member 7 is firmly pressed against the mating face 3a of the lower mold 3 even when the reinforcement member 22 enters between the mating faces 2a, 3a, enabling sufficient sealing between the mating faces 2a, 3a by the seal member 7.

Second Exemplary Embodiment

(37) FIG. 6a is a back face view of a seat pad manufactured using a mold according to a second exemplary embodiment, and FIG. 6b is a plan view of a lower mold of the mold.

(38) In the seat pad 20 of the first exemplary embodiment described above, the reinforcement member 22 is configured so as to cover substantially the entire back face of the seat pad main body 21, and when the reinforcement member 22 has been disposed across the cavity inner face 2b of the upper mold 2, the outer peripheral edge of the reinforcement member 22 is adjacent to the parting line P of the mold 1 around the entire periphery of the parting line P. As a result, in the first exemplary embodiment, the seal member 7 is separated from the inner face of the cavity 4 around the entire periphery of the parting line P by the distance W.sub.1, and the acceptable region for trapping the reinforcement member is formed therebetween. However, in the present embodiment, the reinforcement member 22 may also be configured so as to cover only a portion of the back face of a seat pad main body 21. In such a case, the acceptable region for trapping the reinforcement member between the seal member 7 and the inner face of the cavity 4 may be formed only to portions of the parting line P adjacent to the outer peripheral edge of the reinforcement member 22.

(39) For example, in a seat pad 20A of the second exemplary embodiment, as illustrated in FIG. 6a, the shape of a reinforcement member 22 is configured so as to cover only a front-rear direction rear half side (hereafter simply referred to as the rear half side) of a back face of a seat pad main body 21 during use of the seat pad 20A, and the reinforcement member 22 is disposed up to the outer peripheral edge of the rear half side of the back face of the seat pad main body 21. As a result, when the reinforcement member 22 is disposed across a cavity inner face 2b of an upper mold 2 (not illustrated in FIG. 6b), the outer peripheral edge of the reinforcement member 22 is only adjacent to substantially the half-peripheral portion of the parting line P corresponding to the outer peripheral edge of the back face rear half side of the seat pad main body 21. Accordingly, in the exemplary embodiment, as illustrated in FIG. 6b, it is sufficient to separate the seal member 7 from the inner face of the cavity 4 by the distance W.sub.1 to the parting line P only at substantially the half-peripheral portion rear half side, adjacent to the outer peripheral edge of the reinforcement member 22, and to form the acceptable region for trapping the reinforcement member therebetween.

(40) It is preferable to make the distance from the cavity 4 to the seal member 7 as small as possible at the remaining portion of the parting line P that is not adjacent to the outer peripheral edge of the reinforcement member 22. This thereby prevents unnecessary burring of the seat pad main body 21, or the like, from occurring.

(41) Note that although, as illustrated in FIG. 6b, the seal member 7 is provided to the mating face 2a of the upper mold 2 in the present exemplary embodiment, the seal member 7 may be provided to the mating face 3a of the lower mold 3, or provided to both the mating faces 2a, 3a of the upper mold 2 and the lower mold 3, respectively.

(42) Other configuration of the second exemplary embodiment is similar to the first exemplary embodiment.

Third Exemplary Embodiment

(43) FIGS. 7a, 7b are enlarged cross-section views of the vicinity of a parting line of a mold according to a third exemplary embodiment (a similar portion to that illustrated in FIG. 2). FIG. 7a illustrates a state before mold fastening, and FIG. 7b illustrates a state after mold fastening. Note that FIGS. 7a, 7b illustrate a case in which a reinforcement member has entered the parting line of the mold. FIG. 8 is a plan view of a lower mold of the mold.

(44) In a mold 1A of the exemplary embodiment, a recessed step portion 6 facing inside the cavity 4 is provided to the mating face 3a of the lower mold 3, and a seal member 7 is provided at an opposite side from the cavity 4 than the recessed step portion 6. The recessed step portion 6 is configured such that the reinforcement member 22 can escape inside the recessed step portion 6 in cases in which the reinforcement member 22 enters the parting line P (between the respective mating faces 2a, 3a). Similarly to the first exemplary embodiment, in the present exemplary embodiment, the outer peripheral edge of the reinforcement member 22 is disposed so as to be as adjacent to the parting line P around the entire periphery of the parting line P. As a result, the recessed step portion 6 is also formed around the entire periphery of the mating face 3a, as illustrated in FIG. 8.

(45) As illustrated in FIG. 7b, when the mold 1A has been fastened, a boundary portion Bd.sub.2 between a bottom face of the recessed step portion 6 and the cavity inner face 3b of the lower mold 3, overlaps on the extension direction of the mating faces 2a, 3a with the previously described boundary portion Bd.sub.1 between the mating face 2a and the cavity inner face 2b of the upper mold 2. Note that the respective boundary portions Bd.sub.1, Bd.sub.2 may be offset in the extension direction of the mating faces 2a, 3a when the mold 1A is in a fastened state.

(46) Similarly to the distance W.sub.1 from the inner face of the cavity 4 to the seal member 7, a width W.sub.2 of the recessed step portion 6 from a boundary portion Bd.sub.2 in the mating faces 2a, 3a extension direction and the direction towards and away from the cavity 4 (FIG. 7a; hereafter simply referred to as width W.sub.2), is suitably set corresponding to the acceptable range of attachment error of the reinforcement member 22, pre-set for a seat pad 20 manufactured using the mold 1A. For example, in order to configure the seat pad 20 as a common ordinary vehicle seat, the acceptable range of attachment error of the reinforcement member 22 is approximately from 0 mm to 5 mm. In such cases, the width W.sub.2 of the recessed step portion 6 is preferably from 1 mm to 10 mm, and particularly preferably from 3 mm to 5 mm.

(47) Similarly to the projection height T of the seal member 7, a depth D from the mating face 3a to the bottom face of the recessed step portion 6 (FIG. 7a; hereafter simply referred to as depth D), is suitably set according to the thickness of the reinforcement member 22 used for the seat pad 20. It is preferable to set the depth D of the recessed step portion 6 according to the fabric basis weight in cases in which a fabric material, such as a non-woven fabric, is used as the configuration material of the reinforcement member 22. Specifically, in cases in which the reinforcement member 22 is configured by a non-woven fabric, for example, when the basis weight of the non-woven fabric is from 0.05 kg/m.sup.2 to 0.1 kg/m.sup.2, the depth D is preferably from 0.2 mm to 0.5 mm and particularly preferably from 0.3 mm to 0.4 mm, and when the basis weight of the non-woven fabric is from 0.1 kg/m.sup.2 to 0.2 kg/m.sup.2, the depth D is preferably from 0.3 mm to 0.6 mm and particularly preferably from 0.4 mm to 0.5 mm.

(48) Note that the seal member 7 may be disposed with a spacing toward the cavity 4 outside from the recessed step portion 6, or may be disposed adjacent to the recessed step portion 6. The spacing between the seal member 7 and the recessed step portion 6 is preferably from 1 mm to 10 mm, and particularly preferably from 3 mm to 5 mm.

(49) Other configuration of the mold 1A is similar to the mold 1 of the first exemplary embodiment, and in FIGS. 7a, 7b, 8, the same reference numerals as FIGS. 1 to 5b indicate the same portions. Moreover, the method of manufacturing the seat pad 20 using the mold 1A is similar to when the mold 1 is used.

(50) The mold 1A also exhibits similar advantageous effects to the mold 1 of the first exemplary embodiment.

(51) A recessed step portion 6 facing inside the cavity 4 is provided to the mating face 3a of the lower mold 3 of the mold 1A. The recessed step portion 6 is configured such that the reinforcement member 22 can escape inside the recessed step portion 6 in cases in which the reinforcement member 22 enters the parting line P between the respective mating faces 2a, 3a during mold fastening. The seal member 7 is disposed at the opposite side from the cavity 4 than the recessed step portion 6. As a result, in cases in which the reinforcement member 22 enters between the respective mating faces 2a, 3a when the mold is fastened, not only does the seal member 7 seal between the respective mating faces 2a, 3a, but also at least a portion of the actual reinforcement member 22 escapes inside the recessed step portion 6, such that the sealing abilities of the parting line P are enhanced, and such that molding defects of the seat pad main body 21 caused by the reinforcement member 22 becoming trapped in the parting line P can be more reliably prevented.

(52) Note that, although the recessed step portion 6 is provided to the mating face 3a of lower mold 3 in the present exemplary embodiment, the recessed step portion 6 may be provided to the mating face 2a of the upper mold 2, or provided to both the mating faces 2a, 3a of the upper mold 2 and the lower mold 3, respectively.

Fourth Exemplary Embodiment

(53) FIG. 9 is a plan view of a lower mold of a mold according to a fourth exemplary embodiment.

(54) As in the second exemplary embodiment previously described, in cases in which a reinforcement member 22 is only adjacent to a portion of a parting line P, it is sufficient to only provide a recessed step portion 6 to the portion of the parting line P to which the reinforcement member 22 is adjacent.

(55) It is preferable not to provide the recessed step portion 6 to the remaining portion of the parting line P that is not adjacent to the outer peripheral edge of the reinforcement member 22. This prevents unnecessary burring of the seat pad main body 21, or the like, from occurring.

(56) Other configuration of the fourth exemplary embodiment is similar to that of the second and the third exemplary embodiment.

(57) Each of the exemplary embodiments described above is merely an example of the present invention, and the present invention may be configured differently to the configurations illustrated.

(58) For example, in each of the exemplary embodiments described above, an example is given of the present invention applied to a seat pad; however the present invention is also applicable to a molded foam body other than a seat pad.

(59) The present invention is not limited to the mating faces of an upper mold and a lower mold, and may be applied to all mating locations of a mold, such as between an upper mold and a mold core, or a lower mold and a mold core.

(60) The present invention is explained in detail herein using specific embodiments; however it is obvious to a person skilled in the art than various modifications are possible without departing from the spirit and scope of the invention.

(61) Note that the present application is based on Japanese Patent Application (Patent Application No. 2012-028461) filed on Feb. 13, 2012, the entirety of which is incorporated by reference herein.