Mattress core and mattress

Abstract

To provide a mattress core material and a mattress that enable a natural sleeping posture, facilitates rolling over, and provides comfortable sleep.SOLUTION: A mattress core material 20 according to an embodiment includes an upper layer part 21 formed by a flexible material and a lower layer part 22 formed by a flexible material. The upper layer part 21 and the lower layer part 22 have a flat part 25b having a constant thickness of the mattress core material 20 in a portion on which a waist part of a user is placed. At least one of the upper layer part 21 and the lower layer part 22 has a protrusion 28 protruding upward from the flat part 25b toward a knee of the user, in a portion where a leg part of the user is placed. The lower layer part 22 is formed of a low-repulsion material having an impact resilience of 15% or less. The upper layer part 21 is formed of a high-repulsion material having an impact resilience higher than that of the lower layer part 22.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to mattress cores and mattresses. [Background technology]

[0002] Patent Document 1 describes a mattress made of an elastic material such as polyurethane foam. The mattress has multiple grooves on its top and bottom surfaces. The top surface has raised portions in two locations that come into contact with the waist and knees of the human body. In this mattress, the spacing, width, and depth of the multiple grooves vary from location to location, thereby varying the hardness of the mattress from location to location.

[0003] In the hips and knees, which are concave parts of the human body, the grooves are wide and shallow, and the cross-sectional area is increased by the provision of raised portions. As a result, the cushion maintains a hardness sufficient to support the concave parts of the human body. On the other hand, in the buttocks and heels, which are convex parts of the human body, no raised portions are provided. The grooves in the heels are narrow and deep, which reduces the cross-sectional area of ​​the heels and helps the heels sink.

[0004] Grooves of a certain width and depth are formed on the bottom surface near the waist and knees of the human body. In beds that allow for back and leg lifting, the bed bends at the waist and knees of the human body. By providing multiple grooves in these bending areas, tension and bulging due to bending of the mattress are prevented, making it easier to bend.

[0005] When bending, a gap is created between the human body and the mattress in the lower back area on the flat side, reducing friction between the body and the mattress during bending. Furthermore, the raised portion of the lower back supports the body, preventing it from sliding down toward the feet during bending. The mattress has a two-layer structure on both sides, with the bottom side made of a material that is harder than the material on the flat side. The hardness on the sides makes it easier to get on and off the bed when the mattress is placed on it, and also allows a caregiver to stabilize the body when sitting on the side to provide care. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Design Registration No. 1474570 Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, mattress cores and mattresses are sometimes required to be made of soft materials to fit the user's body. However, if the mattress core is made of a soft material, the body may sink in too much, resulting in an unnatural sleeping position. If the mattress core is made of a soft material, the mattress may cling to the body, making it difficult to turn over in sleep. Therefore, mattress cores and mattresses have room for improvement in terms of sleeping comfort.

[0008] The present disclosure aims to provide a mattress core material and a mattress that allow a sleeping posture to be natural, make it easy to turn over in sleep, and provide good sleeping comfort. [Means for solving the problem]

[0009] (1) The mattress core material according to the present disclosure is a mattress core material on which the user's body rests. The mattress core material comprises an upper layer portion on which the user's body rests and which is made of a flexible material, and a lower layer portion located on the opposite side of the body from the upper layer portion and which is also made of a flexible material. The upper layer portion and the lower layer portion have flat portions where the user's waist rests, where the thickness of the mattress core material is constant. At least one of the upper layer portion and the lower layer portion has raised portions that rise upward from the flat portion toward the user's knees, where the user's legs rest. The lower layer portion is made of a low-resilience material with a resilience of 15% or less, and the upper layer portion is made of a high-resilience material with a resilience higher than that of the lower layer portion. The lower layer has a raised portion, and the thickness of the upper layer is constant at the raised portion.

[0010] In this mattress core, both the upper and lower layers are made of flexible materials. This provides a soft feel to the user who places their body on the mattress core. The upper and lower layers have flat portions with a consistent thickness, and at least one of the upper and lower layers has raised portions that rise upward from the flat portions toward the user's knees. The user's lower back rests on the flat portions. This allows the lower back to be straight when lying on the mattress, achieving a natural sleeping position. The user's lower back rests on the flat portions, and the user's legs, including the knees, rest on the raised portions. The raised portions rise diagonally upward from the user's lower back toward the knees, allowing the mattress core to conform to the shape of the body and achieve a natural sleeping position. The upper layer has higher resilience than the lower layer. This prevents the body from sinking into the upper layer, preventing the mattress from clinging to the body and making it easier to turn over in sleep. Therefore, it is possible to improve the sleeping comfort.

[0011] (2) In the above (1), at least one of the upper and lower layers may have a recess that is recessed downward from the protruding portion where the user's heel rests. In this case, the heel rests on the recess and lowers relative to the knee, allowing the user to maintain a natural leg posture when lying on the mattress. This allows the user to maintain a comfortable leg posture.

[0012] anti The lower layer, which has a lower resilience than the upper layer, has raised portions, allowing the mattress core to be flexibly deformed, giving the user a softer feel. Furthermore, the upper layer has a uniform thickness, which makes it easier to manufacture and reduces the cost of the upper layer.

[0013] (4) In any of the above (1) to (3), the mattress core may have air vents that penetrate the upper and lower layers in the thickness direction of the mattress core. In this case, the mattress core can be soft to the touch, and the air vents can improve the breathability of the mattress core. Therefore, the air vents can prevent stuffiness, further improving sleeping comfort.

[0014] (5) A mattress according to the present disclosure includes the mattress core described in any one of (1) to (4) above and a cover covering the mattress core. This mattress has the aforementioned mattress core. Therefore, this mattress provides the same effects as the aforementioned mattress core. [Effects of the Invention]

[0015] According to the present disclosure, it is possible to maintain a natural sleeping posture, make it easier to turn over in sleep, and improve sleeping comfort. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view showing an example of bedding including a mattress according to an embodiment. [Figure 2] FIG. 2 is a plan view showing a mattress according to the embodiment. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. [Figure 4] FIG. 4 is a plan view showing a mattress core according to an embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing a mattress according to a first modified example. [Figure 6] 6(a) and 6(b) are diagrams showing steps in a method for manufacturing a mattress core for a mattress according to a first modified example. [Figure 7] FIG. 7 is a plan view showing a mattress core according to a second modified example. [Figure 8] Figure 8(a) is a side view showing a mattress core according to a second modified example, and Figure 8(b) is an enlarged cross-sectional view of the mattress core of Figure 8(a). [Figure 9] 9(a), 9(b), and 9(c) are graphs showing the experimental results of the mattress according to the example and the mattress according to the comparative example. [Figure 10] 10(a), 10(b), and 10(c) are graphs showing the experimental results of the mattress according to the example and the mattress according to the comparative example. [Figure 11] 11(a) and 11(b) are graphs showing the experimental results of the mattress according to the example and the mattress according to the comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, embodiments of a mattress core and a mattress according to the present disclosure will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are designated by the same reference numerals, and redundant explanations will be omitted as appropriate. The drawings may be partially simplified or exaggerated to facilitate understanding, and the dimensional proportions and the like are not limited to those shown in the drawings.

[0018] A "mattress" is, for example, bedding. "Bedding" refers to something on which a user's body rests when resting or sleeping. "User" refers to a person who uses the mattress by placing their body on the mattress. Figure 1 is a perspective view showing bedding 1 as an example equipped with a mattress 10 according to this embodiment. As shown in Figure 1, the bedding 1 includes a bed 2, a thick mattress 3 placed on the bed 2, and a mattress 10 placed on the thick mattress 3. In this embodiment, the mattress 10 is a mattress pad that is thinner than the thick mattress 3.

[0019] FIG. 2 is a plan view showing the mattress 10. As shown in FIGS. 1 and 2, the mattress 10 has a rectangular shape in a plan view. The mattress 10 has long sides 11 extending in a first direction D1, which is the longitudinal direction of the mattress 10, and short sides 12 extending in a second direction D2, which is the short side direction (width direction) of the mattress 10. The mattress 10 has a thickness in a third direction D3 (thickness direction) that intersects both the first direction D1 and the second direction D2.

[0020] The mattress 10 has a pair of long sides 11 and a pair of short sides 12. The pair of long sides 11 are aligned along the second direction D2, and the pair of short sides 12 are aligned along the first direction D1. For example, the length of the long sides 11 is 150 cm or more and 250 cm or less (198 cm, for example), and the length of the short sides 12 is 80 cm or more and 200 cm or less (120 cm or 140 cm, for example).

[0021] Fig. 3 is a cross-sectional view taken along line AA in Fig. 2. As shown in Figs. 1 to 3, the mattress 10 has a foot pillow 13 on which the user's legs are placed. For example, the user's body part from the buttocks to the heels is placed on the foot pillow 13. This reduces the gap formed between the mattress 10 and the legs, allowing the user's legs to be aligned with the foot pillow 13 to achieve a natural sleeping posture.

[0022] The mattress 10 comprises a mattress core 20 and a cover 30 that covers the mattress core 20. The cover 30 has, for example, a zipper, and when the zipper is open, the mattress core 20 can be removed from the cover 30 or stored in the cover 30. The cover 30 is made of, for example, fabric. However, the type of material for the cover 30 is not particularly limited.

[0023] The user's body rests on the mattress 10 (mattress core 20). The mattress core 20 comprises an upper layer 21 facing vertically upward and a lower layer 22 facing vertically downward. The upper layer 21 is the portion on which the user's body rests, and the lower layer 22 is located on the opposite side of the upper layer 21 from the body. As an example, the color of the upper layer 21 is different from the color of the lower layer 22. In this case, the upper layer 21 and the lower layer 22 can be easily recognized by the user.

[0024] The upper layer 21 and the lower layer 22 are made of a flexible material. The term "flexible material" refers to a material that is soft enough to be deformed when the body is placed on it. For example, the upper layer 21 is softer than the lower layer 22. However, the hardness (hardness) of the upper layer 21 may be the same as that of the lower layer 22, or the upper layer 21 may be harder than the lower layer 22.

[0025] For example, each of the upper layer 21 and the lower layer 22 is made of urethane. The upper layer 21 and the lower layer 22 are made of a softer urethane. For example, the hardness of the upper layer 21 and the lower layer 22 is less than 90 N (Newtons). The "hardness" is measured, for example, by the measurement method of JIS K 6400-2. As described above, the upper layer 21 and the lower layer 22 are made of a softer urethane, which allows the user of the mattress core 20 to feel a soft sensation.

[0026] However, the hardness of the upper layer 21 and the lower layer 22 is not limited to the above example. For example, the hardness of the upper layer 21 may be 30 N or more and 90 N or less (45 N as an example), and the hardness of the lower layer 22 may be 30 N or more and 95 N or less (65 N as an example). In this way, the hardness of the upper layer 21 and the lower layer 22 can be changed as appropriate.

[0027] In the mattress core 20, the upper layer 21 is made of a high-resilience material, and the lower layer 22 is made of a low-resilience material. "Low-resilience material" refers to a material whose resilience is 15% or less as measured by the measurement method of JIS K 6400-3, for example. In this case, the resilience of the lower layer 22 is 15% or less. The lower layer 22 is made of a low-resilience material with a resilience of 15% or less, and the upper layer 21 is made of a high-resilience material with a resilience higher than that of the lower layer 22.

[0028] "High-resilience material" refers to a material that is not a low-resilience material, i.e., a material with higher resilience than a low-resilience material. In this case, the resilience of the upper layer 21 is higher than 15%. However, the resilience of the upper layer 21 may be 20% or more, 25% or more, or 30% or more. As an example, the resilience of the upper layer 21 is 35% or more.

[0029] In this case, the upper layer 21 located on the upper side of the mattress core 20 has sufficiently high resilience, which prevents excessive sinking and contributes to improved turning over in bed. For example, the upper limit of the resilience of the upper layer 21 is 90%, 80%, 70%, or 60%. However, the upper limit of the resilience of the upper layer 21 may be 50%, for example.

[0030] In this embodiment, upper layer 21 and lower layer 22 have upper body rest 24 on which the user's upper body is placed, waist rest 25 on which the user's waist is placed, leg rest 26 on which the user's legs are placed, and heel rest 27 on which the user's heels are placed. For example, heel rest 27, leg rest 26, waist rest 25, and upper body rest 24 are lined up in this order along first direction D1.

[0031] The upper body resting portion 24 has, for example, a flat portion where the thickness of the mattress core 20 is constant. The lower back resting portion 25 is disposed adjacent to the upper body resting portion 24 in the first direction D1. The upper layer portion 21 and the lower layer portion 22 have a flat portion 25b on the lower back resting portion 25 where the thickness T1 (length in the third direction D3) of the mattress core 20 is constant. For example, the thickness T1 of the lower back resting portion 25 is not less than 1 cm and not more than 10 cm (for example, 4 cm). For example, the thickness of the upper body resting portion 24 is the same as the thickness T1.

[0032] As an example, the length in the first direction D1 of the upper body resting portion 24 is the same as the length in the first direction D1 of the lower back resting portion 25. For example, the lengths in the first direction D1 of the upper body resting portion 24 and the lower back resting portion 25 are 30 cm or more and 70 cm or less. For example, the length in the first direction D1 of the upper body resting portion 24 is 2 / 9 of the length in the first direction D1 of the mattress core 20. In this case, the length in the first direction D1 of the upper body resting portion 24 is 44 cm, for example. However, the upper body resting portion 24 may be any portion as long as it can accommodate the upper body of the user, and the length in the first direction D1 of the upper body resting portion 24 is not limited to the above example.

[0033] At least one of the upper layer 21 and the lower layer 22 has a raised portion 28 on the leg support portion 26 that rises upward from the flat portion 25b toward the user's knees. For example, the lower layer 22 has the raised portion 28, and the thickness of the upper layer 21 is constant at the raised portion 28. For example, in a cross section obtained by cutting the mattress core 20 along a plane extending in the first direction D1 and the third direction D3, the raised portion 28 has a rounded trapezoidal shape. For example, the length of the raised portion 28 in the first direction D1 is 30 cm or more and 120 cm or less (88 cm, for example).

[0034] The raised portion 28 has, for example, an apex 28b which is the thickest portion of the mattress core 20, a first inclined portion 28c which extends diagonally downward from the apex 28b to the flat portion 25b, and a second inclined portion 28d which extends from the apex 28b in the opposite direction to the first inclined portion 28c. The apex 28b is flat and extends in the first direction D1 and the second direction D2.

[0035] The length of the top portion 28b in the first direction D1 is, for example, 30 cm or more and 60 cm or less (for example, 44 cm). For example, the thickness T2 of the mattress core 20 at the top portion 28b is 4 cm or more and 13 cm or less (for example, 7 cm). The difference between the thickness T2 and the thickness T1 is, for example, more than 2 cm and less than 4 cm.

[0036] By making the difference between thickness T2 and thickness T1 greater than 2 cm, the gap between the mattress 10 and the legs can be reduced, allowing the user to sleep in a more natural position. By making the difference between thickness T2 and thickness T1 less than 4 cm, the user can avoid feeling discomfort due to the legs being raised too high. The difference between thickness T2 and thickness T1 is, for example, 3 cm.

[0037] For example, the length of first inclined portion 28c in first direction D1 is 15 cm or more and 30 cm or less (for example, 22 cm). First inclined portion 28c has an inclined extending portion 28c1 extending obliquely with respect to both first direction D1 and third direction D3, a first curved portion 28c2 located between inclined extending portion 28c1 and flat portion 25b, and a second curved portion 28c3 located between inclined extending portion 28c1 and top portion 28b.

[0038] For example, inclined extending portion 28c1 is a flat surface. First curved portion 28c2 is curved so as to be recessed downward, and second curved portion 28c3 is curved so as to be protruding upward. Therefore, first inclined portion 28c has a smooth curved shape.

[0039] For example, the length of second inclined portion 28d in first direction D1 is 15 cm or more and 30 cm or less (for example, 22 cm). At least one of upper layer 21 and lower layer 22 has recess 27b in heel placement portion 27 that is recessed downward from raised portion 28. For example, lower layer 22 has recess 27b, and the thickness of upper layer 21 is constant at recess 27b.

[0040] Second inclined portion 28d has an inclined extending portion 28d1 extending obliquely with respect to both first direction D1 and third direction D3, a first curved portion 28d2 located between inclined extending portion 28d1 and recess 27b, and a second curved portion 28d3 located between inclined extending portion 28d1 and apex 28b. For example, the shapes and sizes of inclined extending portion 28d1, first curved portion 28d2, and second curved portion 28d3 are the same as the shapes and sizes of inclined extending portion 28c1, first curved portion 28c2, and second curved portion 28c3 described above.

[0041] The recess 27b is a portion that is recessed relative to the raised portion 28, and is, for example, flat. In this case, the thickness of the upper layer 21 and the thickness of the lower layer 22 are constant in the recess 27b. For example, the length of the recess 27b in the first direction D1 is shorter than the length of the raised portion 28 in the first direction D1. The length of the recess 27b in the first direction D1 is 15 cm or more and 30 cm or less (for example, 22 cm).

[0042] FIG. 4 is a plan view showing the mattress core 20. As shown in FIG. 4, the mattress core 20 has air holes 29. The air holes 29 penetrate the upper layer 21 and the lower layer 22 in the third direction D3 (the thickness direction of the mattress core 20). For example, the air holes 29 are circular. In this case, tears at the air holes 29 can be made even less likely to occur. For example, the diameter (inner diameter) of the air holes 29 is 1 cm or more and 2 cm or less.

[0043] For example, the mattress core 20 has a plurality of air vents 29. In this case, the plurality of air vents 29 are arranged in a dispersed manner. The term "dispersed" includes, for example, a state in which the plurality of air vents 29 are arranged symmetrically with respect to a predetermined point or line on the mattress core 20, a state in which the plurality of air vents 29 are arranged in a grid pattern, a state in which the plurality of air vents 29 are arranged in a staggered pattern, and a state in which the plurality of air vents 29 are arranged in concentric circles.

[0044] In this embodiment, the multiple air vents 29 are arranged in a grid pattern. For example, the multiple air vents 29 are uniformly arranged in the mattress core 20. The spacing (pitch) between the air vents 29 in the first direction D1 and the spacing between the air vents 29 in the second direction D2 are, for example, 3 cm or more and 30 cm or less.

[0045] Next, an example of a method for manufacturing the mattress 10 will be described. First, the mattress core 20 is manufactured (a mattress core manufacturing step). At this time, a flat upper layer 21 is manufactured (an upper layer manufacturing step), and a lower layer 22 having raised portions 28 is manufactured (a lower layer manufacturing step).

[0046] Next, the upper layer 21 is bonded to the raised portions 28 of the lower layer 22 (bonding step). At this time, an adhesive is applied to the upper surface of the lower layer 22, and the upper layer 21 is bonded to the upper surface of the lower layer 22. This completes the mattress core 20. After the mattress core 20 is completed, the mattress core 20 is placed inside the side fabric 30 (side fabric placement step). Through the above steps, the manufacture of the mattress 10 is completed.

[0047] As described above, in the mattress 10 and mattress core 20 according to this embodiment, as shown in FIG. 3, both the upper layer 21 and the lower layer 22 are made of a flexible material. This provides a soft feel to a user who rests on the mattress core 20. The upper layer 21 and the lower layer 22 have flat portions 25b where the thickness of the mattress core 20 is constant, and at least one of the upper layer 21 and the lower layer 22 has raised portions 28 that rise upward from the flat portions 25b toward the user's knees. The user's lower back rests on the flat portions 25b. This allows the lower back to be straight when lying on the mattress 10, achieving a natural sleeping posture.

[0048] The user's waist rests on flat portion 25b, and the user's legs, including the knees, rest on raised portion 28. Therefore, raised portion 28 rises obliquely upward from the user's waist toward the knees, allowing mattress core 20 to conform to the shape of the body and maintain a natural sleeping posture.

[0049] The upper layer 21 has a higher resilience than the lower layer 22. This prevents the body placed on the upper layer 21 from sinking, preventing the mattress 10 from clinging to the body and making it easier to turn over in sleep, thereby improving sleeping comfort.

[0050] In this embodiment, at least one of the upper layer 21 and the lower layer 22 has a recess 27b that is recessed downward from the protruding portion 28 in the portion where the user's heel rests. In this case, the heel rests on the recess 27b and lowers relative to the knee, allowing the user to maintain a natural leg posture when lying on the mattress 10. This allows the user to maintain a comfortable leg posture.

[0051] In this embodiment, the lower layer 22 has raised portions 28, and the thickness of the upper layer 21 is constant at the raised portions 28. In this case, the lower layer 22, which has lower resilience than the upper layer 21, has raised portions 28, which allows the mattress core 20 to flexibly deform, providing the user with a softer feel. Furthermore, since the upper layer 21 has a constant thickness, the upper layer 21 can be easily manufactured and costs associated with the upper layer 21 can be reduced.

[0052] In this embodiment, the mattress core 20 has air holes 29 that penetrate the upper layer 21 and the lower layer 22 in the thickness direction of the mattress core 20 (third direction D3). In this case, the mattress core 20 can be given a soft feel by the user, and the air holes 29 can improve the breathability of the mattress core 20. Therefore, the air holes 29 can prevent stuffiness, contributing to further improved sleeping comfort.

[0053] Next, various modified examples of the mattress core and mattress will be described. The configuration of some of the mattress cores and mattresses relating to the modified examples described below is the same as the configuration of some of the mattress cores 20 and mattress 10 described above. Therefore, the same components as those of the mattress core 20 and mattress 10 will be assigned the same reference numerals, and duplicate explanations will be omitted where appropriate.

[0054] Fig. 5 is a cross-sectional view showing a mattress 10A according to a first modified example. As shown in Fig. 5, the mattress 10A has a mattress core 20A, which has a plurality of cushion bodies 40. The plurality of cushion bodies 40 have, for example, the same shape and size as the mattress core 20 described above. The plurality of cushion bodies 40 are formed by dividing the mattress core 20. In other words, each of the plurality of cushion bodies 40 has a shape in which the mattress core 20 is divided into a plurality of pieces (for example, three pieces).

[0055] For example, the multiple cushion bodies 40 are a first cushion body 41 including the upper body support portion 24 and a portion of the waist support portion 25, a second cushion body 42 including the remaining portion of the waist support portion 25 and a portion of the leg support portion 26, and a third cushion body 43 including the remaining portion of the leg support portion 26 and the heel support portion 27.

[0056] The first cushion body 41 has a flat shape with a constant thickness (length in the third direction D3). The second cushion body 42 includes the flat portion 25b and a part of the raised portion 28. The second cushion body 42 includes half of the raised portion 28. The third cushion body 43 includes the remaining portion of the raised portion 28 and the recessed portion 27b. The third cushion body 43 includes half of the raised portion 28.

[0057] The first cushion body 41, the second cushion body 42, and the third cushion body 43 are separated from one another inside the side fabric 30A. The side fabric 30A includes an upper fabric 30b facing vertically upward and a lower fabric 30c facing vertically downward. The side fabric 30A has a first sewn portion 31 where the upper fabric 30b, which fits between the first cushion body 41 and the second cushion body 42, is sewn into the lower fabric 30c, and a second sewn portion 32 where the lower fabric 30c, which fits between the second cushion body 42 and the third cushion body 43, is sewn into the upper fabric 30b.

[0058] The side fabric 30A has a first internal space K1 in which the first cushion body 41 is accommodated, a second internal space K2 in which the second cushion body 42 is accommodated, and a third internal space K3 in which the third cushion body 43 is accommodated. The first internal space K1 is an internal space of the side fabric 30A located on the opposite side of the second sewn portion 32 from the first sewn portion 31. The second internal space K2 is an internal space of the side fabric 30A formed between the first sewn portion 31 and the second sewn portion 32. The third internal space K3 is an internal space of the side fabric 30A located on the opposite side of the first sewn portion 31 from the second sewn portion 32.

[0059] Because the side fabric 30A has the first sewn portions 31 and the second sewn portions 32, the mattress 10A can be mountain-folded at the first sewn portions 31 and can be valley-folded at the second sewn portions 32. That is, the first cushion body 41 can be placed below the second cushion body 42 at the first sewn portions 31, and the third cushion body 43 can be placed on the second cushion body 42 at the second sewn portions 32. The above describes an example in which the mattress 10A can be mountain-folded at the first sewn portions 31 and can be valley-folded at the second sewn portions 32. However, the positions, number, and arrangement of the mountain-foldable and valley-foldable portions of the side fabric 30A can be changed as appropriate.

[0060] An example of a manufacturing method for the mattress 10A will be described with reference to Figures 6(a) and 6(b). First, as shown in Figure 6(a), the lower layer 22 of the second cushion body 42 and the lower layer 22 of the third cushion body 43 are manufactured (step of manufacturing the lower layer). For example, a block body B made of the constituent material of the lower layer 22 is prepared (step of preparing the block body).

[0061] The block body B has a rectangular parallelepiped shape and a thickness twice the average thickness of the lower layer portions 22 in the second cushion body 42 and the third cushion body 43. After preparing the block body B, the block body B is cut along a cutting line L that extends in an S-shape from the side surface B1 of the block body B facing horizontally to the side surface B2 facing opposite to the side surface B1 (block body cutting step). By cutting the block body B in this way, two lower layer portions 22 having the same shape are obtained. Therefore, the two lower layer portions 22 can be produced efficiently.

[0062] Furthermore, a flat upper layer portion 21 is fabricated (a step of fabricating an upper layer portion). At this time, an upper layer portion 21 to be placed on the lower layer portion 22 of the second cushion body 42, and an upper layer portion 21 to be placed on the lower layer portion 22 of the third cushion body 43 are fabricated. Thereafter, the upper layer portion 21 is bonded onto the lower layer portion 22 of the second cushion body 42, and the upper layer portion 21 is bonded onto the lower layer portion 22 of the third cushion body 43 (a step of bonding).

[0063] Through the above steps, the second cushion body 42 and the third cushion body 43 are completed (step of manufacturing the second cushion body, step of manufacturing the third cushion body). As shown in Fig. 5, a flat lower layer 22 and a flat upper layer 21 are prepared, and the upper layer 21 is bonded to the lower layer 22 to manufacture the first cushion body 41 (step of manufacturing the first cushion body). Through the above steps, the mattress core 20A is completed.

[0064] Next, the side fabric 30A is produced (a process for producing the side fabric). At this time, a bag-shaped cloth that will form the side fabric 30A is prepared, and the first sewn portion 31 and the second sewn portion 32 are formed by sewing (a process for forming sewn portions). After the side fabric 30A is produced, the first cushion body 41 is housed in the first internal space K1, the second cushion body 42 is housed in the second internal space K2, and the third cushion body 43 is housed in the third internal space K3 (a process for housing cushion bodies). Through these processes, the mattress 10A is completed.

[0065] As described above, the mattress 10A and mattress core 20A have the raised portions 28, as do the mattress 10 and mattress core 20 described above, and also have the upper layer 21 that has higher resilience than the lower layer 22. This allows for a natural sleeping posture and makes it easier to turn over in sleep. Therefore, the mattress 10A and mattress core 20A can achieve the same effects as the mattress 10 and mattress core 20 described above.

[0066] The mattress 10A and the mattress core 20A have multiple cushion bodies 40 that are separated from one another. Therefore, they are foldable and can be made compact. Furthermore, the raised portions 28 of the mattress 10A and the mattress core 20A are separated. Therefore, when the legs are placed on the raised portions 28, the raised portions 28 can sink in appropriately.

[0067] Figure 7 is a plan view showing a mattress core 20B according to a second modified example. Figure 8(a) is a side view showing the mattress core 20B. Figure 8(b) is an enlarged view of a portion of the cross section of the mattress core 20B. As shown in Figures 7, 8(a) and 8(b), the mattress core 20B differs from the mattress core 20 in that it has an upper layer 21B with an uneven portion 45 formed on its upper surface.

[0068] The uneven portion 45 includes a plurality of protruding portions 45b extending in the second direction D2 and a plurality of recessed portions 45c extending in the second direction D2. The protruding portions 45b are portions that protrude upward, and the recessed portions 45c are portions that are recessed downward. In the uneven portion 45, the protruding portions 45b and the recessed portions 45c are alternately arranged along the first direction D1. For example, each of the protruding portions 45b and the recessed portions 45c has an arc shape. However, the shapes of the protruding portions 45b and the recessed portions 45c may be parabolic, rectangular, or trapezoidal, and are not particularly limited. The uneven portion 45 may be a portion having dot-like protruding portions 45b and recessed portions 45c formed by, for example, profile cutting. Furthermore, the mattress core 20B may be formed by bonding together sheet materials having dot-like protruding portions 45b and recessed portions 45c.

[0069] As described above, in the mattress core 20B, the upper layer 21B, which has higher resilience than the lower layer 22, has the uneven portion 45. This increases the resilience, preventing excessive sinking, and improves body pressure distribution. As a result, this contributes to further improving sleeping comfort. Note that in the mattress core 20B, an example has been described in which the protrusions 45b and recesses 45c extend in the second direction D2. However, the protrusions 45b and recesses 45c may also extend in the first direction D1. In this way, the direction in which the protrusions 45b and recesses 45c extend is not particularly limited.

[0070] Next, examples of a mattress core and a mattress according to the present disclosure will be described. Note that the present invention is not limited to the contents of the following examples. Below, experiments conducted on mattresses according to Examples 1 and 2 and a comparative example, which will be described later, will be described. In this experiment, as shown in FIG. 1, a thick mattress 3 was prepared, a mattress was placed on the thick mattress 3, and a body pressure sensor sheet was placed on the mattress. The subjects in the experiment were three women with different BMIs, and each subject was placed on the body pressure sensor sheet on the mattress to measure body pressure distribution, contact area, sinking amount, and turning ability. The thick mattress 3 was a bonnell coil mattress. The specifications of Examples 1, 2, and the comparative example are as follows.

[0071] Example 1 The above-described mattress 10A was placed on top of the thick mattress 3. In the first cushion body 41 and the third cushion body 43 of the mattress 10A, the hardness of the upper layer 21 was 45N, the resilience of the upper layer 21 was 45% or more, the hardness of the lower layer 22 was 65N, and the resilience of the lower layer 22 was 12%. In the second cushion body 42, the hardness of the upper layer 21 was 45N, the resilience of the upper layer 21 was 45% or more, the hardness of the lower layer 22 was 93N, and the resilience of the lower layer 22 was 17% or less. Example 2 The above-described mattress 10A was placed on top of the thick mattress 3. In the first cushion body 41, second cushion body 42, and third cushion body 43 of the mattress 10A, the hardness of the upper layer 21 was 45 N, the resilience of the upper layer 21 was 45% or more, the hardness of the lower layer 22 was 65 N, and the resilience of the lower layer 22 was 12%. The hardness of the lower layer 22 in the second cushion body 42 of Example 2 was set lower than the hardness of the lower layer 22 in the second cushion body 42 of Example 1. (Comparative Example) A mattress made of a low-resilience material and consisting only of the same material as the lower layer 22 was placed on the thick mattress 3. The hardness of the mattress was set to 50N, and the resilience of the mattress was set to 12% or less.

[0072] 9(a), 9(b), and 9(c) are graphs showing the results of measurements of body pressure distribution (maximum body pressure in the supine position, average body pressure in the supine position) and the body contact area with the mattress when a subject lies supine on the mattress. As shown in FIGS. 9(a), 9(b), and 9(c), the mattresses 10A according to Examples 1 and 2 were able to reduce the maximum body pressure in the supine position and the average body pressure in the supine position compared to the mattress according to the comparative example. Example 2, in which the lower layer 22 of the second cushion body 42 had a lower hardness, was able to reduce the maximum body pressure in the supine position and the average body pressure in the supine position even more than Example 1. The contact area was comparable between Examples 1 and 2 and the comparative example, but was slightly larger for the mattress 10A according to Example 2 than for the comparative example and Example 1.

[0073] 10(a), 10(b), and 10(c) are graphs showing the measurement results of body pressure distribution (maximum body pressure in lateral position, average body pressure in lateral position) and the body contact area with the mattress when a subject lies on the mattress in a side-lying position. As shown in FIGS. 10(a), 10(b), and 10(c), the mattress 10A according to Examples 1 and 2 was able to reduce the maximum body pressure and average body pressure in lateral position more than the mattress according to the comparative example. Example 2 was able to further reduce the maximum body pressure and average body pressure in lateral position more than Example 1. From the above, it can be seen that Examples 1 and 2 have better body pressure distribution than the comparative example. The contact area was similar in Examples 1 and 2 and the comparative example, but was slightly larger in the mattress 10A according to Example 2 than in the comparative example and Example 1.

[0074] Fig. 11(a) is a graph showing the measurement results of sleeping posture maintenance (amount of buttocks sinking) when a subject lies supine on the mattress. As shown in Fig. 11(a), the mattress 10A according to Examples 1 and 2 was able to reduce the amount of buttocks sinking compared to the mattress according to the comparative example. The mattress 10A according to Example 2, which has a lower hardness, was able to reduce the amount of buttocks sinking even more than Example 1. It was found that the amount of buttocks sinking was smaller in Examples 1 and 2 than in the comparative example, thereby improving sleeping posture maintenance.

[0075] FIG. 11(b) is a graph showing the measurement results of the ability to turn over (impulse value) when a subject lay on the mattress. The lower the impulse value, the better the ability to turn over. As shown in FIG. 11(b), the mattress 10A according to Examples 1 and 2 was able to reduce the impulse value more than the mattress according to the comparative example. Example 1, in which the lower layer 22 of the second cushion body 42 had a higher hardness, was able to reduce the impulse value even more than Example 2. It was found that Examples 1 and 2 had a smaller impulse value than the comparative example, thereby improving the ability to turn over.

[0076] The above describes embodiments, modifications, and examples of the mattress core and mattress according to the present disclosure. However, the mattress core and mattress according to the present disclosure are not limited to the above-described embodiments, modifications, or examples, and may be further modified within the scope of the gist described in the claims. In other words, the configuration, shape, size, material, number, and arrangement of each part of the mattress core and mattress according to the present disclosure can be modified as appropriate within the scope of the above-described gist.

[0077] For example, in the above-described embodiment, the mattress core 20 is described as having a lower layer 22 with raised portions 28 and a uniform thickness upper layer 21. However, the mattress core may have a uniform thickness lower layer and a raised upper layer. In this case, the flat lower layer makes it easier to attach the upper layer to the lower layer.

[0078] In the above-described embodiment, an example was described in which the recess 27b is provided on the opposite side of the flat portion 25b from the raised portion 28. However, the mattress core may not have the recess 27b. In this case, the raised portion 28 extends to the end of the mattress core 20 in the first direction D1 (the end on the toe side).

[0079] In the first modified example described above, the block body B is cut along the cutting line L to obtain the lower layer portion 22, and then the upper layer portion 21 is bonded to the lower layer portion 22. However, if it is acceptable for the upper surface of the upper layer portion 21 to be uneven, the upper layer portion 21 may be cut along the cutting line after being bonded to the lower layer portion 22.

[0080] In the above-described embodiment, an example has been described in which the plurality of air vents 29 are uniformly arranged in the mattress core 20. However, the plurality of air vents 29 do not have to be uniformly arranged. For example, the density of the air vents 29 formed in the raised portions 28 may be higher than the density of the air vents 29 formed outside the raised portions 28. In this case, the breathability of the raised portions 28 can be further improved.

[0081] In the above-described embodiment, an example has been described in which the mattress 10 is placed on top of the thick mattress 3 placed on the bed 2. However, the mattress does not have to be placed on top of the thick mattress 3, but may be placed on top of a futon, or may be used as a standalone mattress. In this way, there are no particular limitations on how the mattress can be used. [Explanation of symbols]

[0082] 1... bedding, 2... bed, 3... thick mattress, 10, 10A... mattress, 11... long side, 12... short side, 13... foot pillow section, 20, 20A, 20B... mattress core material, 21, 21B... upper layer section, 22... lower layer section, 24... upper body rest section, 25... waist rest section, 25b... flat section, 26... leg rest section, 27... heel rest section, 27b... recessed section, 28... raised section, 28b... top section, 28c... first inclined section, 28c1... inclined extension section, 28c2... first curved section, 28c3... second curved section, 28d... second inclined section, 28d1... inclined extension section , 28d2...first curved portion, 28d3...second curved portion, 29...ventilation hole, 30, 30A...side fabric, 30b...upper fabric, 30c...lower fabric, 31...first sewn portion, 32...second sewn portion, 40...cushion body, 41...first cushion body, 42...second cushion body, 43...third cushion body, 45...uneven portion, 45b...convex portion, 45c...concave portion, B...block body, B1, B2...side surface, D1...first direction, D2...second direction, D3...third direction, K1...first internal space, K2...second internal space, K3...third internal space, L...cutting line.

Claims

1. A mattress core on which a user's body rests, an upper layer portion on which the user's body is placed and which is made of a flexible material; a lower layer portion located on the opposite side of the body from the upper layer portion and made of a flexible material; Equipped with The upper layer and the lower layer have flat portions where the mattress core has a constant thickness, on which the user's lower back rests, At least one of the upper layer and the lower layer has a raised portion that rises upward from the flat portion toward the knees of the user at a portion on which the user's legs are placed, The lower layer is made of a low-resilience material having a resilience of 15% or less, the upper layer is made of a high-resilience material having a higher resilience than the lower layer, the lower layer portion has the raised portion, The thickness of the upper layer portion is constant in the raised portion. Mattress core material.

2. At least one of the upper layer portion and the lower layer portion has a recess that is recessed downward from the raised portion in a portion on which the heel of the user is placed.

2. The mattress core of claim 1.

3. The upper layer and the lower layer have air vents that penetrate the mattress core in the thickness direction.

3. A mattress core according to claim 1 or claim 2.

4. A mattress core according to claim 1 or claim 2; A cover covering the mattress core; A mattress comprising:

Images