Headrest
The headrest design with defoamed foam and impregnated cells addresses void-related defects, enhancing appearance and comfort by facilitating gas escape and integrating a seamless structure.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- INOAC CORP
- Filing Date
- 2024-11-18
- Publication Date
- 2026-05-28
AI Technical Summary
Conventional headrests suffer from defects due to voids generated by trapped gas inside the skin material.
A headrest design that incorporates a defoamed foam with open foam cells on the back surface of the skin material, where a foamed molded body is integrated with an impregnated foam portion, allowing gas escape and reducing void formation.
Suppresses the appearance and tactile defects caused by voids, ensuring a consistent and comfortable touch feel across the headrest.
Smart Images
Figure 2026087686000001_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to a headrest.
Background Art
[0002] As a conventional headrest, one in which a foam molded body is foam molded inside a bag-shaped skin material is known (for example, see Patent Document 1).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
[0046] ,
[0047] , FIG. 3-3, etc.)
Summary of the Invention
Problems to be Solved by the Invention
[0004] In the above-described conventional headrest, there has been a problem that defects occur due to voids generated by the gas trapped inside the skin material.
Means for Solving the Problems
[0005] One aspect of the invention is a headrest including a bag-shaped skin material and a foam molded body foam molded inside the skin material, wherein a defoamed foam having been subjected to a defoaming treatment is overlaid on the back surface of a portion of the skin material disposed from the bottom surface to the front surface or from the bottom surface to the rear surface of the headrest, and an impregnated foam portion formed by foaming the raw material of the foam molded body is provided inside the defoamed foam.
Brief Description of the Drawings
[0006] [Figure 1] FIG. 1A is a perspective view of the headrest according to the first embodiment, and FIG. 1B is a front view of the headrest. [Figure 2] FIG. 2 is a side cross-sectional view of the headrest. [Figure 3]Figure 3 is a cross-sectional view of the impregnated foam portion inside the defilm removal foam. [Figure 4] Figure 4 is a side cross-sectional view of the surface material set inside a foam molding die with raw material injected into it. [Figure 5] Figure 5 is a side cross-sectional view of the surface material and raw material inside a closed foam molding die. [Figure 6] Figure 6 is a side cross-sectional view of a foamed molded body formed by foam molding within the surface material. [Figure 7] Figure 7 is a side cross-sectional view of a headrest in another embodiment. [Figure 8] Figure 8 is a side cross-sectional view of a headrest in another embodiment. [Figure 9] Figure 9 is a side cross-sectional view of a conventional headrest where a void has occurred. [Modes for carrying out the invention]
[0007] [First Embodiment] As shown in Figures 1A and 1B, the headrest 10 according to the first embodiment is provided on a seat 90 for a vehicle (for example, a car). The headrest 10 is formed by foam molding a foamed molded body 15 inside a bag-shaped surface material 20, making it an integral part of the surface material 20. The headrest 10 may be used for purposes other than seats in vehicles, for example, on seats or chairs in buildings (for example, massage chairs or barber chairs).
[0008] In this embodiment, the surface material 20 is a sewn product formed by sewing together a plurality of surface pieces 21 (see Figure 2). In this embodiment, the surface pieces 21 are sewn together at their edges 25 such that the outer surfaces of the surface pieces 21 that are exposed to the outside of the headrest 10 overlap (see Figure 2). The sewn surface pieces 21 are folded in opposite directions at the seam 22, and the overlapping edges 25 of the surface pieces 21 (i.e., the seam allowance) protrude inward from the surface material 20 (see Figure 2). In this embodiment, the surface pieces 21 are non-breathable.
[0009] Furthermore, the bottom surface of the skin material 20 (the bottom surface 10T of the headrest 10) has an opening for the legs 12A of the stay 12 for attaching the headrest to the backrest 91 of the seat 90 to protrude, and a raw material injection section 20K is also formed for injecting the raw material G (see Figures 4 and 5) of the foamed molded body 15 into the inside of the skin material 20 during the molding of the foamed molded body 15. For example, the raw material injection section 20K is formed between a pair of protruding pieces 27 that are not sewn together, among the overlapping edges 25 of the skin piece 21.
[0010] As shown in Figure 2, the headrest 10 is provided with a de-film foam 30 inside the surface material 20. Specifically, in this embodiment, the de-film foam 30 is layered on the back surface of the surface material 20 that is positioned from the bottom surface 10T to the front surface 10Z of the headrest 10. In other words, in this embodiment, the de-film foam 30 is positioned at the corner portion 11 (front corner portion 11A) formed at the lower front of the headrest 10 by the bottom surface 10T and the front surface 10Z of the headrest 10. For example, the de-film foam 30 has a flat shape such as a sheet or plate, and is bent and positioned so as to span the portion of the surface material 20 that is positioned on the bottom surface 10T and the portion that is positioned on the front surface 10Z of the headrest 10. Also, for example, the de-film foam 30 extends in the width direction of the headrest 10 and is positioned from one end to the other in the width direction of the headrest 10 (see Figure 1B). However, the shape of the de-film foam 30 is not limited to this.
[0011] In this embodiment, the headrest 10 has a roughly triangular shape when viewed from the side (see Figure 2), and in addition to the front corner portion 11A, there is an upper corner portion 11C that forms the top of the headrest 10 and a rear corner portion 11B formed at the lower rear of the headrest 10.
[0012] In this embodiment, the boundary portion of the surface material 20 between the portion located on the front surface 10Z of the headrest 10 and the portion located on the bottom surface 10T (i.e., the front corner portion 11A) does not have a stitched portion 22 (seam) between the surface pieces 21. That is, the area of the surface material 20 where the de-film foam 30 overlaps does not have a stitched portion 22 (it is seamless). In this embodiment, however, the boundary portion of the surface material 20 between the portion located on the rear surface 10K of the headrest 10 and the portion located on the bottom surface 10T (i.e., the rear corner portion 11B) does have a stitched portion 22 between the surface pieces 21. Also in this embodiment, the boundary portion of the surface material 20 between the portion located on the front surface 10Z of the headrest 10 and the portion located on the rear surface 10K (i.e., the upper corner portion 11C) also has a stitched portion 22 between the surface pieces 21.
[0013] The defilmed foam 30 is a foam that has undergone a defilming treatment. In the defilmed foam 30, the foam cells 31 are in communication with each other (see Figure 3), and the foam cells 31 open to the outer surface of the defilmed foam 30. The defilming treatment removes the resin film (so-called mirror) between the foam cells 31 of the foam (e.g., a slab-molded foam). In the defilmed foam 30, only the three-dimensional mesh-like skeletal structure 30K of the resin remains after the mirror has been removed. For example, the mirror may be removed by blowing it off with a blast of combustion gas, or by hydrolysis with alkali.
[0014] In the example of this embodiment, an impregnated foam part 15H is formed inside the film-removing foam 30 by the raw material G (see FIG. 4) of the foam molding 15 entering and foaming (see FIG. 3). The impregnated foam part 15H may have air permeability (for example, it may have an open-cell structure), or may be airtight (for example, it may have a closed-cell structure). The apparent density of the film-removing foam 30 including the impregnated foam part 15H is preferably equivalent to the apparent density of the foam molding 15 (for example, the difference is preferably within ±20%, and more preferably within ±10%). By doing so, it becomes possible to make it difficult to feel a sense of incongruity when touching the part of the headrest 10 where the film-removing foam 30 is provided.
[0015] In the example of this embodiment, the film-removing foam 30 is in contact with the skin material 20 (see FIG. 2). And the impregnated foam part 15H reaches the skin material 20. Note that the film-removing foam 30 may not be in contact with the skin material 20, and the resin of the foam molding 15 may enter between the film-removing foam 30 and the skin material 20.
[0016] In the example of this embodiment, the foam molding 15 is a polyurethane foam (for example, a flexible polyurethane foam or a rigid polyurethane foam). For example, the foam molding 15 may be a polyether-based urethane foam or a polyester-based urethane foam. The foam molding 15 is not limited thereto, and may be, for example, a polyethylene foam, a polypropylene foam, or a phenol foam.
[0017] In the example of this embodiment, the film-removing foam 30 is a polyurethane foam. For example, the film-removing foam 30 may be a polyether-based urethane foam or a polyester-based urethane foam. Note that the film-removing foam 30 is not limited thereto, and may be, for example, a polyethylene foam, a polypropylene foam, or a phenol foam.
[0018] The headrest 10 of the present embodiment is manufactured, for example, as follows. First, a bag-shaped skin material 20 in which a plurality of skin pieces 21 are sewn together is prepared. In the example of the present embodiment, non-breathable skin pieces 21 are used. As shown in FIG. 4, a demolding foam 30 is attached to the back surface of the portion of the skin material 20 that is arranged from the bottom surface 10T to the front surface 10Z of the headrest 10 (for example, attached with an adhesive such as double-sided tape). When the skin material 20 is manufactured by sewing the skin pieces 21 together, it is manufactured in a turned-back state (with the back surface facing outward), and then, with the opening of the raw material injection portion 20K as a turning-back port, it is turned right side out and set in the foam molding die 70 (see FIG. 4). The demolding foam 30 is attached to the skin material 20 in the above-mentioned turned-back state.
[0019] As shown in FIG. 4, the skin material 20 is arranged such that the bottom surface 10T of the headrest 10 to be manufactured is on the upper side (that is, the upper corner portion 11C is on the lower side). Then, the raw material G (for example, the raw material of polyurethane foam) of the foam molding body 15 is injected into the skin material 20 from the raw material injection portion 20K.
[0020] Next, the foam molding die 70 is closed (see FIG. 5), and the raw material G foams inside the skin material 20. Then, the foam molding body 15 integrated with the skin material 20 is molded, and the headrest 10 is obtained (see FIG. 6).
[0021] Here, when the raw material G foams and rises inside the skin material 20, if the gas inside the skin material 20 loses a place to escape, voids V may occur in the portion of the skin material 20 that becomes the bottom surface side of the headrest 10 (the portion that becomes the upper side during foam molding) (see FIG. 9). Voids V are likely to occur due to the corner portions 11 arranged on the upper side during the foam molding of the foam molding body 15. In particular, in the corner portion 11 (the front corner portion 11A in the example of the present embodiment) where the sewing portion 22 between the skin pieces 21 is not provided, since gas cannot escape from the sewing portion 22, voids V are likely to occur due to the gas trapped inside the skin material 20. When voids V occur, it may lead to problems such as poor appearance (dents, etc.) and touch feeling.
[0022] In contrast, in this embodiment, the defilm removal foam 30 is provided at the corner portion 11, and in particular at the front corner portion 11A where the sewing portion 22 is not provided. Therefore, compared to the case where there is no defilm removal foam 30, it is possible to suppress the localized generation of large voids V at the corner portion 11, and thus it is possible to suppress defects in appearance and tactile feel caused by voids V.
[0023] The defilm removal foam 30 has foam cells 31 that open to the outside and the foam cells 31 are in communication with each other, so the raw material G is impregnated into the interior of the defilm removal foam 30. Then, as the raw material G foams and the foamed molded body 15 is foamed and molded, the raw material G inside the defilm removal foam 30 also foams and the impregnated foamed portion 15H is formed.
[0024] The number of foam cells 31 in the defilm removal foam 30 is preferably 6 to 16 cells / 25 mm (the number of foam cells 31 can be measured according to JIS K6400-1). If the number of foam cells 31 in the defilm removal foam 30 is 16 cells / 25 mm or less, the foam cells 31 become larger, making it easier for the raw material G of the foamed molded body 15 to impregnate into the cells 31 of the defilm removal foam 30, and also making it easier for the impregnated raw material G to foam. Therefore, it is possible to suppress an increase in the apparent density of the impregnated foamed portion 15H (making the impregnated foamed portion 15H harder). This makes it possible to reduce the feeling of discomfort caused by the part of the headrest 10 where the defilm removal foam 30 (impregnated foamed portion 15H) is provided being harder than other parts. If the number of foam cells 31 in the defilm removal foam 30 is 6 cells / 25 mm or more, it is possible to particularly suppress the formation of large voids V within the defilm removal foam 30. Examples of the defilm removal foam 30 include "MF-8" and "MF-13" manufactured by Inoac Corporation.
[0025] [Other embodiments] The defilm removal foam 30 only needs to be placed on the back surface of the surface material 20 in the portion that is positioned from the bottom surface 10T to the front surface 10Z or from the bottom surface 10T to the rear surface 10K of the headrest 10, and may be arranged as shown in Figure 7. In the example shown in Figure 7, the defilm removal foam 30 is also provided in the rear corner portion 11B (placed on the back surface of the surface material 20 in the portion that is positioned from the bottom surface 10T to the rear surface 10K of the headrest 10). In this case, for example, the defilm removal foam 30 may be placed in the rear corner portion 11B near the stitched portion 22 of the surface material 20 (for example, within 10 mm of the stitched portion 22). For example, the defilm removal foam 30 can be placed on the surface material 20 in two separate portions: the portion that is positioned on the bottom surface 10T of the headrest 10 and the portion that is positioned on the rear surface 10K. In the first embodiment described above, the stitched portion 22 may be provided in the front corner portion 11A where the defilm removal foam 30 is provided. In this case, the de-film foam 30 may be divided into a portion of the surface material 20 that is placed on the bottom surface 10T of the headrest 10 and a portion that is placed on the front surface 10Z, and these portions may be overlapped, or they may overlap the stitched portion 22. Alternatively, the de-film foam 30 may be placed near the stitched portion.
[0026] The deburring foam 30 may be provided at the rear corner portion 11B instead of the front corner portion 11A (see Figure 8). In this case, the sewing portion 22 may or may not be provided at the rear corner portion 11B (see Figure 8). In the latter case, the deburring foam 30 may be arranged in the same manner as in the example in Figure 7.
[0027] In the above embodiment, the defilm removal foam 30 (for example, the edge of the defilm removal foam 30) may overlap the stitching portion 22 between the epidermal pieces 21.
[0028] In the above embodiment, the surface material 20 was a sewn product in which multiple surface pieces 21 were sewn together, but it may also be a product without any seams 22 overall (it may be entirely seamless).
[0029] <Note> The following describes the features extracted from the above embodiments and examples, showing their effects as needed. For ease of understanding, corresponding configurations in the above embodiments will be indicated in parentheses as appropriate, but these features are not limited to the specific configurations indicated in parentheses.
[0030] For example, the following set of features, relating to headrests, can be considered to have been conceived with the background technology that "conventional headrests are known in which a foamed molded body is foamed inside a bag-shaped outer material (see, for example, Japanese Patent Application Publication No. 2014-171801 (paragraphs
[0046] ,
[0047] , Figure 3-3, etc.))." and the problem that "the conventional headrests described above had a problem in that defects occurred due to voids created by gas trapped inside the outer material." Furthermore, there has been a long-standing demand for the development of novel headrests and novel manufacturing methods for headrests.
[0031] [Feature 1] A headrest comprising a bag-shaped outer material and a foamed molded body formed by foam molding inside thereof, On the back surface of the portion of the surface material that is positioned from the bottom to the front or from the bottom to the rear of the headrest, a defilm-removed foam is placed. A headrest having an impregnated foamed section inside the film-removing foam, formed by the foaming of the raw material of the foamed molded body.
[0032] [Feature 2] The headrest according to feature 1, wherein the impregnated foamed portion reaches the surface material.
[0033] [Feature 3] The headrest according to feature 1 or 2, wherein the number of cells in the defilmed foam (number of foam cells 31) is 6 to 16 cells / 25 mm.
[0034] [Feature 4] The aforementioned surface material is made by sewing together multiple pieces of surface material. The headrest according to any one of the features 1 to 3, wherein the area where the defilm-removing foam overlaps in the surface material is seamless.
[0035] [Feature 5] The aforementioned surface material is made by sewing together multiple pieces of surface material. The headrest according to any one of features 1 to 3, wherein the end of the de-film foam is overlapped with the sewn portion.
[0036] [Feature 6] The aforementioned surface material is made by sewing together multiple surface pieces. The lower part of the headrest is provided with a seam where the surface pieces are joined together. The headrest according to any one of features 1 to 3, wherein the end of the defilm foam is overlapped with the sewing portion or positioned near the sewing portion.
[0037] [Feature 7] A method for manufacturing a headrest, comprising arranging a bag-shaped surface material for the headrest so that the bottom surface of the headrest is facing upwards, and foam molding a foamed molded body inside the surface material, A defilm-removed foam is attached to the back surface of the portion of the surface material that is positioned from the bottom to the front or from the bottom to the rear of the headrest, A method for manufacturing a headrest, wherein, during the foam molding process, the raw material for the foamed molded body is impregnated into the defilm foam, causing foaming to occur inside the defilm foam as well.
[0038] Based on the above characteristics, it becomes possible to suppress defects caused by voids.
[0039] While this specification and drawings disclose specific examples of the technology included in the claims, the technology described in the claims is not limited to these specific examples, but also includes various modifications and changes to these examples, as well as parts of the examples taken individually. [Explanation of Symbols]
[0040] 10 headrests 10K rear 10T bottom 10Z front 11 Corner section 11A Front corner section 11B Rear corner section 11C Upper corner section 12 Stay 12A Legs 15 Foamed molded body 15H impregnated foam section 20 Skin material 20K Raw material injection section 21 Epidermal piece 22 Sewing section 25 Edge 27 Protrusion 30 De-film Foam 30K Skeleton Structure 31 foam cells 70 Foam molding dies 90 seats 91 Backrest G raw material V Void
Claims
1. A headrest comprising a bag-shaped outer material and a foamed molded body formed by foam molding inside thereof, On the back surface of the portion of the surface material that is positioned from the bottom to the front or from the bottom to the rear of the headrest, a defilm-removed foam is placed. A headrest having an impregnated foamed section inside the film-removing foam, formed by the foaming of the raw material of the foamed molded body.
2. The headrest according to claim 1, wherein the impregnated foamed portion reaches the surface material.
3. The headrest according to claim 1 or 2, wherein the number of cells in the defilming foam is 6 to 16 cells / 25 mm.
4. The aforementioned surface material is made by sewing together multiple pieces of surface material. The headrest according to claim 1 or 2, wherein the area in the surface material where the defilm-removing foam overlaps is seamless.
5. The aforementioned surface material is made by sewing together multiple pieces of surface material. The headrest according to claim 1 or 2, wherein the end of the de-film foam is overlapped with the sewing portion.
6. A method for manufacturing a headrest, comprising arranging a bag-shaped surface material for the headrest so that the bottom surface of the headrest is facing upwards, and foam molding a foamed molded body inside the surface material, A defilm-removed foam is attached to the back surface of the portion of the surface material that is positioned from the bottom to the front or from the bottom to the rear of the headrest, A method for manufacturing a headrest, wherein, during the foam molding process, the raw material for the foamed molded body is impregnated into the defilm foam, causing foaming to occur inside the defilm foam as well.