Seat back pad and method for manufacturing seat back pad

Abstract

To solve the problem that a conventional structure of a seat back pad is broken at an unintended position when a middle mold is removed.SOLUTION: One aspect of the invention is a seat back pad including a front surface portion, a pair of side surface portions, an upper surface portion, and a flange portion formed to be bent from rear ends of the pair of side surface portions and the upper surface portion to a rear side of the front surface portion, the seat back pad further including; a through-hole which is formed in at least one of the side surface portion and the top surface portion and corresponds to a component to be assembled to the seat back; and a weakened portion which extends from the tip of the flange portion toward the base end side, includes a notch, a slit, or a breakable thin portion. The weakened portion is provided at a position on the flange portion corresponding to the through hole.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a seat back pad and a method for manufacturing the same. [Background technology]

[0002] BACKGROUND ART A conventional seat back pad that can be molded using a molding die having a medium size is known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4541778 (see paragraphs

[0014] ,

[0024] ,

[0025] ,

[0029] , Figures 1 to 3, 5, 7, etc.) Summary of the Invention [Problem to be solved by the invention]

[0004] With the conventional seat back pad structure described above, there is a risk of the pad breaking in an unintended position when a medium-sized seat back pad is removed from the mold, and a solution to this problem is needed. [Means for solving the problem]

[0005] One aspect of the invention is a seat back pad having a front portion, a pair of side portions, an upper portion, and a flange portion formed by bending from the rear ends of the pair of side portions and the upper portion to the rear side of the front portion, wherein the seat back pad is provided with a through hole formed in at least one of the side portions and the upper portion corresponding to a part to be assembled to the seat back, and a weak portion extending from the tip of the flange portion toward the base end, the weak portion including a notch, a slit, or a breakable thin portion, wherein the weak portion is provided at a position in the flange portion corresponding to the through hole. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a front perspective view of a seat provided with a seat back pad; [Figure 2] Rear perspective view of the seat back pad [Figure 3] Side cross-sectional view of seat back pad [Figure 4] Cross-sectional view of the seat back pad taken along line AA in Figure 3 [Figure 5] Cross-sectional view of the seat back pad taken along line BB in Figure 3 [Figure 6] Side cross-sectional view of a foam molding mold in a closed state [Figure 7] Cross-sectional view of the foam molding mold taken along line CC in Figure 6 [Figure 8] A side cross-sectional view of a seat back pad foam-molded in a foam molding mold. [Figure 9] A cross-sectional view of the seat back pad foam-molded in the foam molding mold along the line DD in FIG. 8. [Figure 10] A cross-sectional side view of the middle mold and seat back pad when the foam molding mold is opened. [Figure 11] Cross section of the protrusion and upper flange taken along line EE in Figure 10 [Figure 12] FIG. 10 is a cross-sectional plan view of a seat back pad according to another embodiment, which is foam-molded in a foam molding mold; [Figure 13] FIG. 10 is a cross-sectional plan view of a seat back pad according to another embodiment, which is foam-molded in a foam molding mold; [Figure 14] FIG. 10 is a rear perspective view of a seat back pad according to another embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0007] [First embodiment] As shown in Figures 1 and 2, the seat back pad 10 of this embodiment is used in a seat back 92 (backrest portion) of a seat 90. In this embodiment, the seat 90 is for a front seat of a vehicle, but it may also be for a rear seat. The seat 90 to which the seat back pad 10 is applied may be for a vehicle other than a vehicle, or may be for a building. For example, the seat back 92 is configured such that the seat back pad 10 is covered with a cover 93.

[0008] As shown in FIGS. 3 and 4, the seatback pad 10 of this embodiment includes a front surface 11, a pair of side surfaces 12, and a top surface 13. The front surface 11 is a front portion of the seatback pad 10 that includes the front surface that supports a seated occupant. In this embodiment, the front surface 11 has a generally rectangular shape when viewed from the front (see FIG. 1). The pair of side surfaces 12 include the left and right surfaces of the seatback pad 10, respectively, and protrude rearward from the front surface 11. The top surface 13 includes the upper surface of the seatback pad 10 and protrudes rearward from the front surface 11. That is, in this embodiment, at the outer edge of the rear surface of the seatback pad 10, the pair of side surfaces 12 protrude from the left and right sides, and the top surface 13 protrudes from the upper side. In this embodiment, the protruding portions of these three sides (referred to as "rear protruding portions 17" as appropriate) are connected to each other.

[0009] In this embodiment, a lower surface portion 16 including the lower surface of the seat back pad 10 also protrudes rearward from the front surface portion 11. In this embodiment, rear protrusions 17 of the lower surface portion 16 that protrude rearward from the lower edge of the front surface portion 11 are separated from the rear protrusions 17 of each side surface portion 12 (see FIG. 2).

[0010] The seat back pad 10 is provided with flange portions 15 that bend rearward (inward as viewed from behind) from the rear ends (rear ends of the rear protrusions 17) of the pair of side surface portions 12 and the top surface portion 13. In this embodiment, the flange portions 15 bent from the top surface portion 13 (referred to as "upper flange portions 15U") are connected to flange portions 15 bent from the pair of side surface portions 12 (referred to as "side flange portions 15S"). In this embodiment, the seat back pad 10 is also provided with flange portions 15 (referred to as "lower flange portions 15D") that bend rearward (inward as viewed from behind) from the rear ends of the lower surface portion 16 (rear ends of the rear protrusions 17) of the front surface portion 11. In this embodiment, the lower flange portions 15D are not connected to the side flange portions 15S.

[0011] 2 and 3, the rear surface of the seatback pad 10 is surrounded by the front surface 11, the pair of side surfaces 12, the top surface 13, and the flanges 15 bent therefrom (and in this embodiment, the bottom surface 16 and the lower flange 15D as well), forming a concave rear surface receiving portion 19 that is open to the rear. A component (not shown), such as a seatback frame, is received in the rear surface receiving portion 19. The seatback pad 10 is fixed to the seatback frame.

[0012] In this embodiment, the seat back pad 10 is an integrally molded product in which a front surface portion 11, a pair of side surfaces 12, an upper surface portion 13, and a flange portion 15 are integrally molded, and is made of foamed resin.

[0013] The seat back pad 10 of this embodiment is formed with a through hole 20 corresponding to a component P to be assembled to the seat back 92. For example, the component P may be a headrest 96 (see FIGS. 1 and 3) or a seat belt, and the component P is inserted through the through hole 20. In this embodiment, the through hole 20 is provided in the upper surface portion 13 of the seat back pad 10, and a stay 96S of the headrest 96 is passed through the through hole 20 (e.g., a round hole) (see FIG. 3). Note that, for example, when the seat back pad 10 is used in the rear seat of a vehicle, the upper surface portion 13 may be formed with a through hole 20 (e.g., a rectangular hole) through which a seat belt is passed. The shape of the through hole 20 is not limited to these examples and can be designed appropriately depending on the component P.

[0014] 2, the seat back pad 10 has a fragile portion 30 provided in the flange portion 15. In this embodiment, a slit 30S is formed as the fragile portion 30, and the fragile portion 30 (slit 30S) extends from the tip (inner edge 15E) of the flange portion 15 toward the base end side of the flange portion 15 (outer side when viewed from the rear).

[0015] In this embodiment, the fragile portion 30 is provided at a position corresponding to the through hole 20 in the flange portion 15. Specifically, in this embodiment, the position (range) where the through hole 20 is formed and the position (range) where the fragile portion 30 (slit 30S) are formed overlap (at least partially overlap) in the width direction (left-right direction) of the seat back pad 10. For example, the fragile portion 30 (slit 30S) may be formed linearly. In this case, it is preferable that the position of the slit 30S (the center position of the slit 30S in the width direction) is the same as the position of the through hole 20 (the center position of the through hole 20) in the left-right direction (see FIGS. 2 and 5).

[0016] As shown in FIG. 5, in this embodiment, the slit 30S (weakened portion 30) narrows (for example, gradually narrows) toward the outer surface side (rear surface side) of the flange portion 15.

[0017] The seat back pad 10 of this embodiment is manufactured, for example, as follows. Figures 6 and 7 show a foam molding die 50 for foam-molding the seat back pad 10. The foam molding die 50 has a plurality of split dies. In this embodiment, the split dies include a lower die 51, an upper die 52, and a middle die 60 attached to the upper die 52. Note that this embodiment is merely an example of the configuration of the foam molding die 50, and the configuration of the foam molding die 50 (such as the configuration of the split dies and the mold opening direction) is not limited to this.

[0018] In the mold closed state, the lower mold 51 and the upper mold 52 are overlapped and abutted in the vertical direction, and in the mold open state, the upper mold 51 and the lower mold 52 are separated. In this embodiment, one end of the upper mold 52 is connected to one end of the lower mold 52 by a hinge 54, and the mold is opened by the upper mold 52 rotating relative to the lower mold 52 about the hinge 54 (see FIG. 10). Note that, for example, the foam molding mold 50 can also be configured to change between the mold closed state and the mold open state by linearly moving at least one of the upper mold 52 and the lower mold 52 in the vertical direction.

[0019] Lower mold 51 is container-shaped and has a molding recess 51U that is open on the upper side. Upper mold 52 is lid-shaped and closes molding recess 51U of lower mold 51. In the mold closed state, molding recess 51U of lower mold 51 is closed by upper mold 52, thereby forming cavity 55 in which seat back pad 10 is molded inside foam molding die 50. A fitting opening 52K into which middle mold 60 is fitted is formed in the center of the lower surface of upper mold 52.

[0020] The intermediate die 60 is attached by fitting into the fitting opening 52K of the upper die 52. In the closed state, the intermediate die 60 protrudes from the lower surface of the upper die 52 into the cavity 55 (inside the molding recess 51) and is disposed at a distance from the inner surface of the molding recess 51U. The intermediate die 60 has a protruding portion 61 at its tip end portion in the protruding direction from the upper die 52. The protruding portion 61 protrudes laterally (in a direction intersecting the protruding direction) beyond a base end portion 62 of the intermediate die 60 that fits into the fitting opening 52K, and is disposed at a distance from the molding surface (lower surface) of the upper die 52.

[0021] In this embodiment, the seat back pad 10 is foam-molded with the front portion 11 facing downward and the flange portion 15 facing upward. Specifically, the molding recess 51U of the lower mold 51 molds the outer surfaces of the front portion 11, the pair of side portions 12, and the top portion 13 of the seat back pad 10 (and also the outer surface of the bottom portion 16 in this embodiment). The middle mold 60 molds the inner surfaces of the front portion 11, the pair of side portions 12, and the top portion 13 of the seat back pad 10 (and also the inner surface of the bottom portion 16 in this embodiment). Of these, the protruding portion 61 of the middle mold 60 molds the inner surface of the rear receiving portion 19 of the seat back pad 10. That is, the front portion 11 of the seat back pad 10 is molded between the protruding portion 61 and the bottom surface of the molding recess 51U in the cavity 55. Furthermore, the pair of side surfaces 12, the upper surface 13, and the lower surface 16 of the seat back pad 10 are molded between the outer peripheral surface of the protruding portion 61 and the inner peripheral surface of the molding recess 51U. The upper mold 50 also molds the outer surface of the flange portion 15. That is, the flange portion 15 is molded between the protruding portion 61 and the upper mold 52.

[0022] As shown in FIG. 6 , a protrusion 68 that forms the through hole 20 is formed on the outer peripheral surface of the overhanging portion 61. In this embodiment, the protrusion 68 is disposed on an upper surface forming surface 63 of the outer peripheral surface of the overhanging portion 61 that forms the upper surface portion 13. A protrusion wall 65 that forms the slit 30S of the fragile portion 30 protrudes from an upper mold facing surface 64 of the overhanging portion 61 that faces the upper mold 52. The protrusion wall 65 is formed so as to straddle the overhanging portion 61 and the base end portion 62 of the middle mold 60 and connect them. In this embodiment, the protrusion wall 65 is disposed so as to abut against the upper mold 52 in the mold closed state. This allows the slit 30S of the seat back pad 10 to be formed so as to penetrate the upper flange portion 15U. The protrusion wall 65 is formed, for example, so as to become thinner (e.g., gradually thinner) toward the upper mold 52. This allows the slit 30S to be formed in a shape that narrows toward the outer surface side (rear surface side) of the flange portion 15.

[0023] In this embodiment, the protruding wall 65 is disposed at a position corresponding to the protruding portion 68 in the width direction (left-right direction) of the seat back pad 10. It is preferable that the formation position (range) of the protruding wall 65 and the formation position (range) of the protruding portion 68 in the left-right direction overlap (at least partially overlap). In this embodiment, the position of the protruding wall 65 (center position in the thickness direction) and the position of the protruding portion 68 (center position) are the same in the left-right direction.

[0024] A foaming resin raw material is injected into the foam molding die 50, and when it foams and hardens, the seat back pad 10 is molded in the cavity 55 (see FIGS. 8 and 9). Then, the foam molding die 50 is opened, and the seat back pad 10 is demolded.

[0025] 10 , when the upper mold 52 and the middle mold 60 are separated from the lower mold 51, the seat back pad 10 may be left behind in the lower mold 51 depending on the shapes of the seat back pad 10 and the foam molding die 50. For example, this occurs when the catch portion between the flange portion 15 and the protruding portion 61 is small, or when the corner between the front surface portion 11 and the upper surface portion 13 catches on the lower mold 51. In this case, the conventional seat back pad 10 and its manufacturing method have a problem in that when the protruding portion 68 is removed from the through-hole 20 and moves over the flange portion 15, the protruding portion 68 catches on the flange portion 15, causing the flange portion 15 to tear at an unintended position.

[0026] In contrast, in this embodiment, a fragile portion 30 (slit 30S) is formed in the flange portion 15 at a position corresponding to the through hole 20. Therefore, as shown in FIG. 11 , the protrusion 68 passes through the interior of the fragile portion 30 (inside the slit 30S) while deforming (expanding) the fragile portion 30, thereby enabling the seat back pad 10 to be demolded. This makes it possible to prevent the flange portion 15 from being torn at an unintended position by the protrusion 68. For example, it is preferable that the fragile portion 30 (slit 30S) be disposed on a path along which the protrusion 68 moves relative to the seat back pad 10 during demolding. Furthermore, in this embodiment, the fragile portion 30 facilitates deformation of the flange portion 15, thereby making it possible for the overhanging portion 61 to pass through the flange portion 15 more easily.

[0027] [Other embodiments] In the above embodiment, the fragile portion 30 may include a slit 30S, a notch, or a breakable thin portion, and may extend from the tip (inner edge 15E) of the flange portion 15 toward the base end (outside) of the flange portion 15. For example, in the foam molding mold 50 shown in FIG. 12 , the protruding wall 65 does not abut against the upper mold 52 when the mold is closed. In this configuration, a groove-shaped fragile portion 30 (recess) recessed toward the inner surface of the flange portion 15 is formed in the foam-molded seat back pad 10. The groove bottom of this groove-shaped recess serves as the above-mentioned breakable thin portion 30V. With this configuration, by removing the seat back pad 10 so that the protruding portion 68 passes over the fragile portion 30 (so that it passes through the interior of the fragile portion 30), the protruding portion 68 is less likely to get caught on the flange portion 15, making it easier to remove the seat back pad 10 from the mold. In this configuration, even if the thin-walled portion 30V is torn by the protrusion 68 during demolding, it is possible to make the seat back pad 10 less susceptible to defects compared to when the flange portion 15 is torn at an unintended position (for example, it is possible to improve the appearance of the seat back pad 10). Also, in a configuration in which the thin-walled portion 30V is molded in this manner, the thin-walled portion 30V may remain without being torn during demolding. In this case, the seat back pad 10 obtained has the thin-walled portion 30V remaining in the fragile portion 30 (at least in a part of the fragile portion 30) instead of the slits 30S of the above embodiment.

[0028] In the above embodiment, when the slit 30S is formed, the protruding wall 65 that forms the slit 30S may be formed on both the upper die 52 and the middle die 60 so that they abut against each other (see FIG. 13), or may be provided only on the upper die 52. In the former case, for example, the slit 30S may have a shape that narrows midway along the front-to-rear direction of the flange portion 15. In the latter case, the slit 30S may be configured to widen toward the outer surface (for example, gradually widen). In addition, the slit 30S may have a uniform width along the front-to-rear direction of the flange portion 15.

[0029] In the above embodiment, the through hole 20 may be formed in at least one of the upper surface portion 13 and the side surface portion 12, or may be formed in both the upper surface portion 13 and the side surface portion 12. The fragile portion 30 may be formed in at least one of the upper flange portion 15U and the side flange portion 15S, or may be formed in both the upper flange portion 15U and the side flange portion 15S as shown in FIG. 14 . In this case, the through hole 20 may be formed in at least one of the upper surface portion 13 and the side surface portion 12. When the through hole 20 is not provided in the side surface portion 12, the fragile portion 30 including a slit 30S, a notch, or a breakable thin portion 30V may be formed in the side flange portion 15S at a midpoint in the up-down direction of the seat back pad 10. This makes it possible to prevent the side flange portion 15S, which has a wider molding area than the upper flange portion 15U, from tearing at an unintended position. When the through hole 20 is provided in the side surface portion 12, for example, the fragile portion 30 may be provided in the side flange portion 15S at an intermediate position corresponding to the through hole 20 in the up-down direction of the seat back pad 10 (for example, at the same position as the through hole 20 in the up-down direction). When the fragile portion 30 is provided in the side flange portion 15S, a plurality of fragile portions 30 may be provided in the flange portion 15, and some of the fragile portions 30 may be disposed at intermediate positions in the up-down direction of the side flange portion 15S.

[0030] In the above embodiment, after foam molding of the seat back pad 10, when the upper mold 52 and the middle mold 60 are separated from the lower mold 51 to open the foam molding die 50, the seat back pad 10 may get caught on the middle mold 60 (extending portion 61) and be lifted up together with the middle mold 60 without being left in the lower mold 51. In this case, the seat back pad 10 needs to be removed from the middle mold 60. Specifically, the flange portion 15 needs to be removed from the middle mold 60 (extending portion 61) by widening the opening of the rear surface receiving portion 19 of the seat back pad 10. In this case, too, by removing the flange portion 15 from the middle mold 60 so that the protruding portion 68 of the middle mold 60 passes inside the fragile portion 30 of the seat back pad 10, it is possible to prevent the flange portion 15 of the seat back pad 10 from being positioned in an unintended position during demolding.

[0031] In the above embodiment, the seat back pad 10 may be made of, for example, an elastic resin other than foamed resin (for example, rubber, etc.).

[0032] In the above embodiment, when a reinforcing panel or other surface material is placed on the inner surface of the rear receiving portion 19, it is preferable to form a slit, cut, or breakable portion in the panel material at a position corresponding to the fragile portion 30.

[0033] <Additional Notes> The following describes the features extracted from the above embodiment, while indicating, as necessary, the effects, etc. Note that, for ease of understanding, the corresponding configurations in the above embodiment are indicated in parentheses as appropriate below, but these features are not limited to the specific configurations indicated in parentheses.

[0034] For example, the following group of features of the present disclosure relate to a "seat back pad and a manufacturing method thereof" and can be considered to have been conceived in response to the following problem in the background art: "Conventional seat back pads are known that can be molded using a molding die having a medium mold (see, for example, Japanese Patent No. 4541778 (paragraphs

[0014] ,

[0024] ,

[0025] ,

[0029] , Figures 1 to 3, 5, 7, etc.)." "In the structure of the conventional seat back pad as described above, the pad may tear at an unintended position when the medium mold is removed from the die, and a solution to this problem is required." Furthermore, there has long been a demand for the development of new technologies related to seat back pads and manufacturing methods thereof.

[0035] [Feature 1] A seat back pad having a front surface, a pair of side surfaces, an upper surface, and a flange portion formed by bending from rear ends of the pair of side surfaces and the upper surface toward the rear side of the front surface, a through hole formed in at least one of the side surface portion and the top surface portion, the through hole corresponding to a component to be assembled to the seat back; a fragile portion extending from the tip of the flange portion toward the base end side, the fragile portion including a notch, a slit, or a breakable thin portion; The weakened portion is provided in the flange portion at a position corresponding to the through hole of the seat back pad.

[0036] [Feature 2] the through hole is provided in the upper surface portion, The seat back pad according to feature 1, wherein the fragile portion is arranged in a position of the flange portion bent from the upper surface portion that overlaps with the position of the through hole in the width direction of the seat back pad.

[0037] [Feature 3] a plurality of the fragile portions are provided on the flange portion, A seat back pad according to feature 1 or 2, wherein a portion of the plurality of fragile portions is located at a midpoint in the vertical direction of the seat back pad in the flange portion bent from the side portion.

[0038] [Feature 4] A seat back pad described in any one of features 1 to 3, wherein the fragile portion has a groove-like shape that is recessed on the inner surface side of the flange portion, and the width of the fragile portion gradually narrows as it approaches the outer surface side of the flange portion.

[0039] [Feature 5] A manufacturing method for manufacturing the seat back pad according to any one of Features 1 to 4 using a foam molding mold, The foam molding mold includes: a first molding die (lower die 51) for molding the outer surfaces of the front surface portion, the pair of side surface portions, and the top surface portion; a second molding die (middle die 60) that molds the front surface, the pair of side surfaces, the top surface, and the inner surface (rear surface receiving portion 19) of the flange; a third molding die (upper die 52) that molds the outer surface of the flange portion, the second molding die has a protrusion for molding the through hole, A method for manufacturing a seat back pad, in which, after the seat back pad is molded, when the foam molding mold is opened, the seat back pad is demolded from the second mold so that the protrusion passes through the inside of the fragile portion.

[0040] Although the present specification and drawings disclose specific examples of the technology included in the scope of the claims, the technology described in the claims is not limited to these specific examples, but also includes various modifications and variations of the specific examples, and also includes parts of the specific examples taken out alone. [Explanation of symbols]

[0041] 10 Seat back pad 11 Front part 12 Side part 13 Top part 15 Flange 15D Lower flange 15E Inner edge 15S side flange 15U upper flange 16 Bottom part 17 Posterior protrusion 19 Rear receptor 20 through holes 30 Weakened part 30S slit 30V thin section 50 Foam molding mold 51 Lower mold 51U Molded recess 52 Upper mold 52K mating opening 54 Hinge 55 Cavity 60 medium size 61 Overhang 62 Proximal part 63 Upper molding surface 64 Upper die facing surface 65 Projection wall 68 Protrusion 90 sheets 92 seat back 96 Headrest 96S Stay

Claims

1. A seat back pad having a front surface, a pair of side surfaces, an upper surface, and a flange portion formed by bending from rear ends of the pair of side surfaces and the upper surface toward the rear side of the front surface, a through hole formed in at least one of the side surface portion and the top surface portion, the through hole corresponding to a component to be assembled to the seat back; a fragile portion extending from the tip of the flange portion toward the base end side, the fragile portion including a notch, a slit, or a breakable thin portion; The weakened portion is provided in the flange portion at a position corresponding to the through hole of the seat back pad.

2. the through hole is provided in the upper surface portion, The seat back pad according to claim 1 , wherein the fragile portion is disposed in the flange portion bent from the upper surface portion at a position that overlaps with the position of the through hole in the width direction of the seat back pad.

3. a plurality of the fragile portions are provided on the flange portion, The seat back pad according to claim 2 , wherein some of the plurality of weak portions are disposed at intermediate positions in the up-down direction of the flange portion bent from the side surface portion.

4. 2. The seat back pad according to claim 1, wherein the weakened portion has a groove shape recessed on an inner surface side of the flange portion, and the width of the weakened portion gradually narrows toward an outer surface side of the flange portion.

5. A manufacturing method for manufacturing the seat back pad according to any one of claims 1 to 4 using a foam molding mold, comprising: The foam molding mold includes: a first mold for molding the outer surfaces of the front surface portion, the pair of side surface portions, and the top surface portion; a second mold for molding the front surface portion, the pair of side surface portions, the top surface portion, and the inner surface of the flange portion; a third molding die for molding the outer surface of the flange portion, the second molding die has a protrusion for molding the through hole, A method for manufacturing a seat back pad, wherein when the foam molding mold is opened after the seat back pad has been molded, the seat back pad is demolded from the second mold so that the protrusion passes through the inside of the fragile portion.

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