Core material for pillow

Abstract

To provide a core material for pillow which is capable of maintaining a user's lying posture in a comfortable state and of improving feeling in sleep.SOLUTION: A core material 1 for pillow has a first surface 1a facing a user and a second surface 1b facing opposite the first surface 1a in a first direction D1, and is composed with a soft material. The core material 1 for pillow is provided with: a head support part 2 supporting a back head part of the user; and a cervical vertebra support part 3 supporting the cervical vertebra of the user and adjacent to the head support part 2 in a second direction D2 crossing the first direction D1. The head support part 2 has a first recess 21 opening to the first surface 1a and into which the back head part enters. The cervical vertebra support part 3 has: a projection 31 including the first surface 1a and projecting in the first direction D1; and a second recess opening to the second surface 1b and arranged side by side with the projection 31 along the first direction D1.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a core material for a pillow.

Background Art

[0002] Japanese Utility Model Publication No. 6-070666 discloses a pillow having a surface facing the user and a surface facing the opposite side of the surface facing the user, and being composed of a flexible material. This pillow includes a flat surface that supports the head of a user lying on their back and a protruding portion that abuts against the user's neck muscles.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is known that fatigue accumulates in the body due to disrupted postures such as when using a smartphone or during desk work. For example, stiffness may occur in the body due to a straight neck or a hunched back. The stiffness of the body can be stretched by maintaining a good posture. For example, by maintaining a good sleeping posture with a pillow, stretching can be performed while lying down.

[0005] The above-described pillow includes a flat surface that supports the back of the user's head and a protruding portion that supports the user's cervical vertebrae. Since the shape of the cervical vertebrae varies depending on the individual user, the above-described pillow does not always enable the user to maintain a good posture. Furthermore, when the shape of the protruding portion does not match the shape of the user's cervical vertebrae, the pressure applied from the back of the user's head to the cervical vertebrae is not appropriately dispersed, so there is a risk of deterioration in comfort.

[0006] The present disclosure provides a core material for a pillow that can keep the user's sleeping posture in a good state and improve the comfort.

Means for Solving the Problem

[0007] The pillow core material according to the present disclosure has (1) a first surface facing the user and a second surface facing the opposite of the first surface in the first direction, and is a pillow core material composed of a flexible material. The pillow core material includes a head support portion that supports the back of the user's head and a cervical vertebra support portion that supports the user's cervical vertebrae and is adjacent to the head support portion in a second direction intersecting the first direction. The head support portion has a first concave portion that opens on the first surface and into which the back of the head enters. The cervical vertebra support portion includes the first surface, has a convex portion protruding in the first direction, and a second concave portion that opens on the second surface and is arranged along the first direction with the convex portion.

[0008] This pillow core material has a first surface facing the user and a second surface facing the opposite of the first surface in the first direction. The pillow using the pillow core material is placed on the placement surface with the second surface facing it. The pillow core material includes a head support portion that supports the back of the user's head and a cervical vertebra support portion that supports the user's cervical vertebrae. The head support portion and the cervical vertebra support portion are adjacent to each other in the second direction and support two points of the back of the head and the cervical vertebrae, so the sleeping posture from the back of the user's head to the cervical vertebrae can be defined. The head support portion has a first concave portion that opens on the first surface and into which the back of the head enters. Since the back of the head of the user lying on their back enters the first concave portion, the head support portion can maintain the user's sleeping posture. The cervical vertebra support portion includes the first surface, has a convex portion protruding in the first direction, and a second concave portion that opens on the second surface and is arranged along the first direction with the convex portion. The convex portion of the cervical vertebra support portion supports the cervical vertebrae of the user lying on their back. The second concave portion forms a space between the placement surface. Since the space is located opposite to the convex portion in the first direction, the convex portion of the cervical vertebra support portion deforms so as to sink into the space. By deforming so that the convex portion sinks in, the cervical vertebra support portion deforms along the user's cervical vertebrae, and the sleeping posture from the back of the head to the cervical vertebrae of each user can be improved.

[0009] As a result, this pillow core can keep the sleeping posture of the user in a good state by the cervical support part deforming along the cervical vertebrae of each user and the occipital part getting into the first concave part of the head support part. This pillow core can stretch the stiffness caused by, for example, a straight neck or hunchback by stretching the back muscles of the user. Further, since the pressure applied from the occipital part to the cervical vertebrae of the user is appropriately dispersed, this pillow core can improve the comfort of the user during sleep.

[0010] (2) In the above (1), the head support part may have a third concave part that opens on the second surface and is arranged along the first direction with the first concave part. The third concave part forms a space between the head support part and the placement surface on which the pillow core is placed. The space is located opposite to the first concave part in the first direction. The head support part that supports the occipital part of the user that has entered the first concave part deforms so as to sink into the space. By the head support part and the cervical support part deforming respectively, this pillow core can keep the sleeping posture from the occipital part to the cervical vertebrae of the user in an even better state. Further, since the pressure applied from the occipital part to the cervical vertebrae of the user is more appropriately dispersed, this pillow core can further improve the comfort of the user during sleep.

[0011] (3) In the above (2), the head support portion may have a groove that opens to the inner surface defining the first concave portion. The groove may extend so as to form an annular shape. The portion where the groove of the head support portion extends has a thickness smaller than the thickness along the first direction of the portion where the groove of the head support portion does not extend. Since the portion where the groove of the head support portion extends is easily deformable, the annular inner portion separated by the groove is easily deformed so as to sink into the space between the third concave portion and the placement surface. Therefore, the head support portion can be more easily deformed at the inner portion of the annular shape than at the outer portion of the annular shape. For example, for the gently curved back of the head, by the support of the outer portion of the annular shape separated by the groove, the head support portion can support the entire back of the head so that it does not sink. For example, for the sharply curved back of the head, by the sinking of the inner portion of the annular shape separated by the groove, the head support portion can be deformed along the shape of the back of the head. As a result, this pillow core material can support the position of the user's back of the head at an appropriate height, so that the sleeping posture from the user's back of the head to the cervical vertebra can be maintained in an even better state. In addition, since the pressure applied to the user's back of the head is more appropriately dispersed, this pillow core material can further improve the user's comfort in sleeping.

[0012] (4) In any one of the above (1) to (3), the convex portion may include a pair of tops facing each other in a third direction intersecting both the first direction and the second direction. The cervical vertebra may enter between the pair of tops. Since the pair of tops press the left and right muscles of the cervical vertebra as seen from a user lying on their back, the stiffness of the user's neck can be stretched.

[0013] (5) In any one of the above (1) to (4), the pillow core material may further include a thoracic vertebra support portion that is adjacent to the cervical vertebra support portion in the second direction and supports the thoracic vertebra of the user. The thoracic vertebra support portion may protrude in the second direction from the cervical vertebra support portion. Since the thoracic vertebra support portion supports the thoracic vertebra located between a pair of scapulae of the user, the pair of scapulae rotate inward so as to approach each other. By the pair of scapulae rotating inward, the thoracic vertebra support portion can keep the sleeping posture from the thoracic vertebra to the scapulae of the user in a good state. Also, by the pair of scapulae rotating inward, both shoulders move to the rear side of the user, so the thoracic vertebra support portion can stretch, for example, the stiffness caused by hunched shoulders.

[0014] (6) In any one of the above (1) to (5), the pillow core material may further include a pair of cheek support portions that support the cheeks of a user lying on their side. In a third direction that intersects both the first direction and the second direction, a head support portion may be located between the pair of cheek support portions. Each cheek support portion may have a depression that opens to both the end face on the cervical vertebra support portion side in the second direction and the second face. The depression forms a space between it and the placement surface. By deforming so that the cheek support portion sinks into the space according to the rollover from sleeping on the back to sleeping on the side, the cheek support portion can promote the rollover from sleeping on the back to sleeping on the side. Furthermore, since the opening of the end face in the second direction deforms, the cheek support portion 5 can appropriately disperse the pressure applied to the temporal region of the user lying on their side.

[0015] (7) In the above (6), the pillow core material may further include a pair of arm holding portions that protrude in the second direction from the pair of cheek support portions so as to face the upper arms of a user lying on their side in the third direction. In the third direction, the ends of the pair of arm holding portions may be located outside the ends of the pair of cheek support portions. A user lying on their side can hold the arm holding portion between the upper arm and the lower arm by bending the elbow along the end of the arm holding portion. When bending the elbow along the end of the arm holding portion, the lower arm as seen from the user lying on their side is located in front of the upper arm, so the arm holding portion can stabilize the sleeping posture of the user lying on their side.

[0016] (8) In any one of (1) to (7) above, the pillow core material may further include an adjusting member having a plate shape. The adjusting member may include a main surface facing the second surface and an end surface intersecting the main surface. At least a part of the end surface may define a space together with at least one of the second concave portion, the third concave portion, and the depression. The adjusting member is disposed between the second surface of the pillow core material and the placement surface. Therefore, the user can appropriately adjust the height of the pillow core material using the adjusting member. Further, since the adjusting member has a notch along at least one of the second concave portion, the third concave portion, and the depression, the user can widen the space between at least one of the second concave portion, the third concave portion, and the depression and the placement surface by the notch.

[0017] (9) In any one of (1) to (8) above, the pillow core material may further include an adjusting member having a plate shape. The adjusting member may have a raised portion that rises along the inner surface defining the third concave portion, and a concave portion that opens on the surface opposite to the raised portion and is arranged along the first direction with the raised portion. A space is formed between the concave portion that is recessed along the surface of the raised portion of the adjusting member and the placement surface. Therefore, the user can adjust the height of the pillow core material using the adjusting member and appropriately adjust the size of the space adjacent to the first concave portion in the first direction. As a result, the user can adjust the amount by which the head support portion deforms so as to sink.

Advantages of the Invention

[0018] According to the present disclosure, it is possible to keep the sleeping posture of the user in a good state and improve the comfort of sleep.

Brief Description of the Drawings

[0019]

Figure 1

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DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, embodiments and modifications of the pillow core material 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 denoted by the same reference numerals, and overlapping descriptions are omitted as appropriate. Also, the drawings may be drawn with some parts simplified or exaggerated for ease of understanding, and the dimensional ratios and the like are not limited to those shown in the drawings.

[0021] The pillow core material 1 according to the present disclosure is composed of a flexible material. The "flexible material" refers to a cushioning material that deforms when a body is placed on it and receives a load. In one example, the flexible material may be urethane foam. The pillow core material 1 may be formed by urethane molding. The "pillow core material" refers to the core material of a pillow. The pillow core material 1 is used by a user in a state of being housed in a pillow cover. However, the pillow core material 1 itself may be used by the user as a pillow.

[0022] The pillow core material 1 has a first surface 1a facing the user and a second surface 1b facing the opposite side of the first surface 1a in the first direction D1. The pillow core material 1 is placed on a placement surface. The second surface 1b faces the placement surface. In the present embodiment, the first direction D1 is along the vertical direction. Hereinafter, being located vertically downward in the first direction D1 may be referred to as "low", and being located vertically upward in the first direction D1 may be referred to as "high". FIG. 1 is a perspective view showing the pillow core material 1 according to an embodiment. FIG. 1 is a perspective view in the direction in which the first surface 1a is shown. FIG. 2 is another perspective view showing the pillow core material 1 according to an embodiment. FIG. 2 is a perspective view in the direction in which the second surface 1b is shown. The first surface 1a of the pillow core material 1 is shown in the plan view of FIG. 3. The second surface 1b of the pillow core material 1 is shown in the bottom view of FIG. 4.

[0023] The pillow core material 1 has a thickness along the first direction D1 and extends along both the second direction D2 and the third direction D3. The second direction D2 intersects the first direction. The third direction D3 intersects both the first direction and the second direction. In the present embodiment, the second direction D2 is along the vertical direction as seen from a user lying on their back using the pillow core material 1. Hereinafter, the lower part as seen from a user lying on their back using the pillow core material 1 may be referred to as "front", and the upper part as seen from a user lying on their back using the pillow core material 1 may be referred to as "rear". In the front view of FIG. 5, the front surface of the pillow core material 1 is shown. In the rear view of FIG. 7, the rear surface of the pillow core material 1 is shown. The third direction D3 is along the left - right direction as seen from a user lying on their back using the pillow core material 1. In the side view of FIG. 6, the side surface of the pillow core material 1 as seen from the third direction D3 is shown. In the present embodiment, the first direction D1, the second direction D2, and the third direction D3 are orthogonal to each other.

[0024] As shown in FIGS. 1 to 4, the pillow core material 1 includes a head support portion 2, a cervical vertebra support portion 3, a thoracic vertebra support portion 4, a pair of cheek support portions 5, and a pair of arm holding portions 6. In the present embodiment, the head support portion 2, the cervical vertebra support portion 3, the thoracic vertebra support portion 4, the pair of cheek support portions 5, and the pair of arm holding portions 6 are integrally formed.

[0025] In FIGS. 5 to 11, the pillow core material 1 is placed on the placement surface P. The placement surface P is separate from the pillow core material 1. The placement surface P is the surface of the bedding. The bedding includes a bed and a futon. In the present embodiment, the placement surface P is orthogonal to the first direction D1. The placement surface P extends along both the second direction D2 and the third direction D3. In FIGS. 5 to 11, the pillow cover for accommodating the pillow core material 1 and the sheet covering the bedding are not shown. Hereinafter, with reference to FIGS. 1 to 11, the pillow core material 1 according to the present disclosure will be described.

[0026] The head support part 2 supports the back of the user's head. As shown in FIG. 3, the head support part 2 has a first concave part 21 that opens to the first surface 1a. The back of the user's head fits into the first concave part 21. The head support part 2 is configured to support, for example, the load in the first direction D1 applied from the back of the head of a user lying on their back. The inner surface 2a that defines the first concave part 21 may be formed of a curved surface. In one example, the inner surface 2a follows the back of the user's head. The first concave part 21 is deeper at positions closer to the center in the second direction D2. The first concave part 21 is deeper at positions closer to the center in the third direction D3. The head support part 2 includes an end face 2f on the side opposite to the cervical vertebra support part 3 in the second direction D2. The end face 2f is the rear face of the head support part 2. The end face 2f is an inclined face facing the placement surface P. The end face 2f is farther from the placement surface P as it is closer to the end in the second direction D2.

[0027] The cervical vertebra support part 3 is adjacent to the head support part 2 in the second direction D2. The cervical vertebra support part 3 supports the user's cervical vertebrae. The cervical vertebra support part 3 has a convex part 31 and a second concave part 32. The convex part 31 includes the first surface 1a and protrudes in the first direction D1. The cervical vertebra support part 3 supports, for example, so that the cervical vertebrae of a user lying on their back do not float. In one example, the first surface 1a of the convex part 31 follows the user's cervical vertebrae. When viewed from the first direction D1, the convex part 31 may have an outer shape with the second direction D2 as the longitudinal direction and the third direction D3 as the short direction. In one example, the convex part 31 has an elliptical shape with a major axis along the second direction D2. The first surface 1a of the convex part 31 may be formed of a curved surface. In one example, the maximum value of the radius of curvature of the first surface 1a of the convex part 31 in a cross section orthogonal to the third direction D3 is larger than the maximum value of the radius of curvature of the first surface 1a of the convex part 31 in a cross section orthogonal to the second direction D2.

[0028] The convex portion 31 is higher at a position closer to the center in the second direction D2. The convex portion 31 is higher than the center in the second direction D2 of the inner surface 2a of the first concave portion 21. As shown in FIG. 8, in a cross section orthogonal to the third direction D3, the first surface 1a of the convex portion 31 and the inner surface 2a of the first concave portion 21 are continuous. The first surface 1a of the convex portion 31 and the inner surface 2a of the first concave portion 21 constitute an inclined surface inclined with respect to the placement surface P. As shown in FIG. 5, the cervical vertebra support portion 3 includes a pair of lower portions 35 adjacent to the convex portion 31 in the third direction D3. The lower portion 35 is located at the end of the cervical vertebra support portion 3 in the third direction D3. In the third direction D3, the convex portion 31 is located between the pair of lower portions 35. The lower portion 35 may be the lowest in the cervical vertebra support portion 3. The lower portion 35 may be lower than the highest portion of the head support portion 2. The first surface 1a of the cervical vertebra support portion 3 is inclined from the lower portion 35 to the convex portion 31. In the third direction D3, the cervical vertebra support portion 3 may be smaller than the first concave portion 21. For example, in the third direction D3, the distance between the pair of lower portions 35 is smaller than the maximum width of the first concave portion 21.

[0029] As shown in FIG. 8, the second concave portion 32 opens to the second surface 1b. The second concave portion 32 is arranged along the first direction D1 with the convex portion 31. The second concave portion 32 may be recessed along the first surface 1a of the convex portion 31. In a cross section orthogonal to the third direction D3, the cervical vertebra support portion 3 may exhibit an arch shape. The second concave portion 32 is deeper at a position closer to the center in the second direction D2. The second concave portion 32 is deeper at a position closer to the center in the third direction D3. For example, as shown in FIG. 4, when viewed from the first direction D1, the second concave portion 32 exhibits a substantially elliptical shape having a major axis along the second direction D2. The inner surface 3b defining the second concave portion 32 may be a curved surface. In one example, the maximum value of the radius of curvature of the inner surface 3b in a cross section orthogonal to the third direction D3 is larger than the maximum value of the radius of curvature of the inner surface 3b in a cross section orthogonal to the second direction D2.

[0030] In the second direction D2, the second recess 32 may extend from one end of the cervical vertebra support portion 3 to the other end of the cervical vertebra support portion 3. For example, the second recess 32 extends from the end of the cervical vertebra support portion 3 on the head support portion 2 side to the end of the cervical vertebra support portion 3 on the thoracic vertebra support portion 4 side. In one example, the inner surface 3b includes an inclined surface that inclines away from the placement surface P in the first direction D1 as it moves away from the portion facing the placement surface P of the thoracic vertebra support portion 4 in the second direction D2. The second recess 32 may be included in both the cervical vertebra support portion 3 and the head support portion 2. In this case, the ends of the second recess 32 may be aligned along the first direction D1 with the head support portion 2. The second recess 32 may be included in both the cervical vertebra support portion 3 and the thoracic vertebra support portion 4. In this case, the ends of the second recess 32 may be aligned along the first direction D1 with the thoracic vertebra support portion 4. The second recess 32 forms a space with the placement surface P. The space is located on the opposite side of the convex portion 31 in the first direction D1.

[0031] The head support portion 2 has a third recess 22. The third recess 22 opens to the second surface 1b. As shown in FIG. 8, the third recess 22 is aligned with the first recess 21 along the first direction D1. When viewed from the first direction D1, the third recess 22 is smaller than the first recess 21 (see FIG. 4). The head support portion 2 includes a portion where the third recess 22 and the first recess 21 are adjacent to each other in the first direction D1 and a portion where the third recess 22 and the first recess 21 are not adjacent to each other in the first direction D1. The second surface 1b of the portion where the third recess 22 and the first recess 21 are not adjacent to each other in the first direction D1 faces the placement surface P. In the head support portion 2, the portion where the third recess 22 and the first recess 21 are adjacent to each other in the first direction D1 has a smaller thickness than the portion where the third recess 22 and the first recess 21 are not adjacent to each other in the first direction D1.

[0032] The third recess 22 is deeper at a position closer to the center in the second direction D2. The third recess 22 is deeper at a position closer to the center in the third direction D3. The inner surface 2b defining the third recess 22 may be a curved surface. The thickness of the head support portion 2 is smaller at a position closer to the center in the second direction D2. The thickness of the head support portion 2 is smaller at a position closer to the center in the third direction D3. The third recess 22 forms a space with the placement surface P.

[0033] As shown in FIG. 1, the head support portion 2 has a groove 23 that opens to the inner surface 2a of the first concave portion 21. The groove 23 extends so as to form an annular shape. In the present embodiment, the groove 23 extends so as to form an elliptical shape when viewed in the first direction D1. When viewed in the first direction D1, the groove 23 overlaps with the third concave portion 22. The portion of the head support portion 2 where the groove 23 extends has a smaller thickness than the portion of the head support portion 2 where the groove 23 does not extend. The groove 23 separates the inner portion 24 of its annular shape from the outer portion 25 of its annular shape. The inner portion 24 of the annular shape may be lower than the outer portion 25 of the annular shape.

[0034] The convex portion 31 of the cervical vertebra support portion 3 includes a pair of top portions 33 that face each other in the third direction D3. In the third direction D3, the distance between the pair of top portions 33 is smaller than the maximum width of the first concave portion 21. The top portion 33 is the top of the convex portion 31 in the first direction D1. In the present embodiment, the heights of the pair of top portions 33 are equal to each other. In the cervical vertebra support portion 3, the top portion 33 is the highest. The cervical vertebra of the user fits between the pair of top portions 33. The pair of top portions 33 support the left and right muscles of the cervical vertebra when viewed from a user lying on their back. The portion between the pair of top portions 33 is lower than the pair of top portions 33. A groove 34 that extends along the second direction D2 may be formed between the pair of top portions 33. The groove 34 may be deeper the closer it is to the center in the second direction D2.

[0035] The thoracic vertebra support portion 4 is adjacent to the cervical vertebra support portion 3 in the second direction D2. The thoracic vertebra support portion 4 is located in front of the cervical vertebra support portion 3. The thoracic vertebra support portion 4 protrudes from the cervical vertebra support portion 3 in the second direction D2. The thoracic vertebra support portion 4 supports the thoracic vertebra of the user. The thoracic vertebra support portion 4 supports the portion of the thoracic vertebra located between a pair of scapulae and does not support the scapulae. The maximum width of the thoracic vertebra support portion 4 in the third direction D3 may be shorter than the distance between a pair of scapulae of the user. The thoracic vertebra support portion 4 includes an end face 4c in the second direction D2 and a pair of end faces 4d in the third direction D3.

[0036] The thoracic vertebra support portion 4 is lower at positions closer to the end face 4c. The first surface 1a of the thoracic vertebra support portion 4 inclines such that it is lower at positions closer to the end face 4c. The thoracic vertebra support portion 4 is lower at positions closer to the end face 4d. The first surface 1a of the thoracic vertebra support portion 4 inclines such that it is lower closer to the end face 4d. The width of the thoracic vertebra support portion 4 in the third direction D3 is smaller at positions closer to the cervical vertebra support portion 3. The end face 4d inclines such that the width of the thoracic vertebra support portion 4 in the third direction D3 is smaller at positions closer to the cervical vertebra support portion 3. As shown in FIG. 8, the first surface 1a of the cervical vertebra support portion 3 and the first surface 1a of the thoracic vertebra support portion 4 are continuous. The first surface 1a of the cervical vertebra support portion 3 and the first surface 1a of the thoracic vertebra support portion 4 constitute an inclined surface that inclines with respect to the placement surface P.

[0037] As shown in FIG. 3, between the pair of cheek support portions 5 in the third direction D3, the head support portion 2 is located. The cheek support portions 5 are located on the left and right as viewed from the user U with the back of the head supported by the head support portion 2. As shown in FIG. 11, the cheek support portions 5 support the cheeks of the user U lying on the side. For example, the cheek support portions 5 support the cheeks and the temporal regions of the user U who has turned over from the state of lying on the back with the back of the head supported by the head support portion 2. Both ends of the cheek support portions 5 in the second direction D2 are located more forward in the third direction D3 as they are farther from the head support portion 2.

[0038] The cheek support portion 5 includes an end face 5c on the cervical vertebra support portion 3 side in the second direction D2, an end face 5e in the third direction D3, and an end face 5f on the head support portion side in the second direction D2. The end face 5c is the front face of the cheek support portion 5. The end face 5f is the rear face of the cheek support portion 5. As shown in FIG. 4, the end face 5e and the end face 5f are continuous. The end face 5f and the end face 2f are continuous. The end face 5c is an inclined surface facing the placement surface P. In a cross-section along the first direction D1, the end face 5c is farther from the placement surface P at positions closer to the end. The end face 5f is an inclined surface facing the placement surface P. In a cross-section along the first direction D1, the end face 5f is farther from the placement surface P at positions closer to the end. The end face 5e is an inclined surface facing the placement surface P. In a cross-section along the first direction D1, the end face 5e is farther from the placement surface P at positions closer to the end in the third direction D3.

[0039] The cheek support portion 5 has a depression 51, a fourth recess 52, and a chamfered portion 53. As shown in FIGS. 4 and 5, the depression 51 opens to both the second surface 1b and the end surface 5c. The depression 51 does not open to the end surface 5f. The depression 51 may have a substantially triangular shape with the opening of the end surface 5c as the base when viewed from the first direction D1. In one example, the depression 51 has a parabolic shape convex on the side opposite to the opening of the end surface 5c when viewed from the first direction D1. The depression 51 may have a substantially semi-circular shape with the opening on the second surface 1b side as the lower chord when viewed from the second direction D2.

[0040] The depression 51 viewed from the end surface 5c extends along a direction away from the center of the pillow core material 1 in the third direction D3. For example, the depression 51 viewed from the first direction D1 extends along a depth direction inclined with respect to the second direction D2. The X-X line shown in FIG. 4 is along the depth direction. As shown in FIG. 4, the depth direction viewed from the first direction D1 may be inclined within a range of 5 degrees or more and 45 degrees or less with respect to the second direction D2. In one example, the depth direction viewed from the first direction D1 is inclined 12 degrees from the second direction D2. When viewed from the first direction D1, the width of the depression 51 along the direction orthogonal to the depth direction is larger closer to the end surface 5c. When viewed from the first direction D1, the depression 51 is deeper in the first direction D1 at a position closer to the center of the opening of the end surface 5c. When viewed from the depth direction, the depression 51 is deeper in the depth direction at a position closer to the center of the opening of the second surface 1b.

[0041] As shown in FIG. 10, the depression 51 forms a space with the placement surface P. The inner surface 5b defining the depression 51 is an inclined surface facing the placement surface P. In a cross-section along the first direction D1, the inner surface 5b is farther from the placement surface P at a position closer to the end surface 5c. For example, the inner surface 5b includes a first inclined surface 56 and a second inclined surface 57. The first inclined surface 56 is continuous from the second surface 1b facing the placement surface P. The second inclined surface 57 is continuous from the first inclined surface 56 and is closer to the end surface 5c than the first inclined surface 56. In a cross-section along the first direction D1, the inclination of the first inclined surface 56 with respect to the placement surface P is larger than the inclination of the second inclined surface 57 with respect to the placement surface P.

[0042] As shown in FIG. 3, the fourth recess 52 opens to the first surface 1a of the cheek support portion 5. When viewed from the first direction D1, the fourth recess 52 has a substantially semi-circular shape whose chord faces the end face 5c. The zygomatic bone of the lying user U fits into the fourth recess 52. As shown in FIG. 9, the inner surface 5a defining the fourth recess 52 includes a third inclined surface 54 and a fourth inclined surface 55. The arc of the substantially semi-circular shape of the fourth recess 52 is the edge of the third inclined surface 54, and the chord of the substantially semi-circular shape of the fourth recess 52 is the edge of the fourth inclined surface 55. Note that the shape of the fourth recess 52 when viewed from the first direction D1 can be changed as appropriate. When viewed from the first direction D1, the fourth recess 52 may be circular, elliptical, or spindle-shaped. The inner surface 5a defining the fourth recess 52 is not limited to the third inclined surface 54 and the fourth inclined surface 55. The inner surface 5a defining the fourth recess 52 may include at least one curved surface.

[0043] As shown in FIG. 6, the chamfered portion 53 is a portion where the angle between the first surface 1a of the cheek support portion 5 and the end face 5e is chamfered. The surface of the chamfered portion 53 is continuous with the first surface 1a and the end face 5e of the cheek support portion 5. The chamfered portion 53 is a partial chamfer formed such that the end in the second direction D2 is continuous with the angle between the first surface 1a of the cheek support portion 5 and the end face 5e. The chamfered portion 53 has a spindle shape when viewed from a direction orthogonal to its surface.

[0044] As shown in FIG. 11, the arm holding portion 6 protrudes from the cheek support portion 5 in the second direction D2 so as to face the upper arm Ua of the lying user U in the third direction D3. In the third direction D3, the end of the arm holding portion 6 is located outside the end of the cheek support portion 5. In the second direction D2, the end of the arm holding portion 6 may be located in front of the end of the thoracic vertebra support portion 4. The arm holding portion 6 is located outside in the third direction D3 as it moves away from the cheek support portion 5 in the second direction D2.

[0045] As shown in FIG. 4, the arm holding portion 6 includes an end face 6d on the side of the cervical vertebra support portion 3 in the third direction D3, an end face 6c in the second direction D2, and an outer end face 6e in the third direction D3. The end face 6d is an inclined face facing the mounting surface P. The end face 6d is farther away from the mounting surface P as it is closer to the end in the second direction D2 (see FIG. 5). The end face 6e is an inclined face facing the mounting surface P. The end face 6e is farther away from the mounting surface P as it is closer to the end in the third direction D3 (see FIG. 7). The end face 6d and the end face 5c are continuous. The end face 6d and the end face 6c are continuous. The end face 6e and the end face 6c are continuous. The end face 6e and the end face 5e are continuous.

[0046] As shown in FIG. 6, the end face 6c may extend along the first direction D1. The inclination of the end face 6c with respect to the first direction D1 as viewed from the third direction D3 is smaller than the inclination of the end face 6d with respect to the first direction D1 as viewed from the second direction D2. The inclination of the end face 6c with respect to the first direction D1 as viewed from the third direction D3 is smaller than the inclination of the end face 6e with respect to the first direction D1 as viewed from the second direction D2.

[0047] As shown in FIG. 11, the arm holding portion 6 and the thoracic vertebra support portion 4 face each other in the second direction D2. The arm A of the user U is located in the space between the arm holding portion 6 and the thoracic vertebra support portion 4. The end face 6d faces the upper arm Ua of the user U lying on the side. The end face 5c faces the shoulder S of the user U lying on the side. The end face 4d faces the upper arm Ua of the user U lying on the side. In the example shown in FIG. 11, the end face 6d faces the front surface of the upper arm Ua of the right arm of the user U lying on the side in the third direction D3. The end face 5c faces the upper surface of the shoulder S of the right arm of the user U lying on the side in the second direction D2. The end face 4d faces the back surface of the upper arm Ua of the right arm of the user U lying on the side in the third direction D3.

[0048] The pillow core material 1 may further include an adjustment member 7. FIG. 12 is a front view showing the pillow core material provided with the adjustment member. FIG. 13 is a bottom view showing the pillow core material provided with the adjustment member. FIG. 14 is an end view taken along the line XIV-XIV of FIG. 13. Hereinafter, the adjustment member 7 will be described with reference to FIGS. 12 to 14.

[0049] The adjustment member 7 is made of a flexible material. The adjustment member 7 may be made of the same material as the pillow core material 1. The pillow core material 1 may be formed by urethane molding. The adjustment member 7 is separate from the pillow core material 1. The adjustment member 7 is separate from the placement surface P. As shown in FIG. 12, the adjustment member 7 is disposed between the pillow core material 1 and the placement surface P. The adjustment member 7 is used together with the pillow core material 1 to adjust the height of the pillow. The adjustment member 7 is used by the user in a state of being housed in the pillow cover together with the pillow core material 1. However, when the pillow core material 1 itself is used as a pillow by the user, the adjustment member 7 may also be used as a pillow.

[0050] The adjustment member 7 has a plate shape. As shown in FIGS. 12 and 13, the adjustment member 7 has a plate shape along a direction orthogonal to the first direction D1. The adjustment member 7 includes a main surface 7a facing the second surface 1b of the pillow core material 1. In the present embodiment, the adjustment member 7 has a first adjustment member 71, a second adjustment member 72, and a pair of third adjustment members 73. The first adjustment member 71, the second adjustment member 72, and the pair of third adjustment members 73 each include the main surface 7a. The first adjustment member 71 and the head support portion 2 are adjacent to each other in the first direction D1. The second adjustment member 72 and the thoracic vertebra support portion 4 are adjacent to each other in the first direction D1. At least one of the first adjustment member 71 and the second adjustment member 72 is adjacent to the cervical vertebra support portion 3 in the first direction D1. As shown in FIG. 14, both the first adjustment member 71 and the second adjustment member 72 may be adjacent to the cervical vertebra support portion 3 in the first direction D1. The third adjustment member 73 and the arm holding portion 6 are adjacent to each other in the first direction D1. The third adjustment member 73 and the cheek support portion 5 are adjacent to each other in the first direction D1. Note that the first adjustment member 71, the second adjustment member 72, and the pair of third adjustment members 73 may be integrated.

[0051] When viewed from the first direction D1, the outer shape of the first adjusting member 71 is along the end face 2f. When viewed from the first direction D1, the outer shape of the first adjusting member 71 does not overlap with the end face 2f. When viewed from the first direction D1, the outer shape of the second adjusting member 72 is along the end faces 4c and 4d. When viewed from the first direction D1, the outer shape of the second adjusting member 72 does not overlap with the end faces 4c and 4d. When viewed from the first direction D1, the outer shape of the third adjusting member 73 is along the end faces 6d, 6c, 6e, and 5e. The outer shape of the third adjusting member 73 does not overlap with the end faces 6d, 6c, 6e, and 5e. The first adjusting member 71 has an end face 71d that defines a space together with the recess 51. The end face 71d intersects the main face 7a. When viewed from the first direction D1, the end face 71d is along at least a part of the opening in the second face 1b of the recess 51. The third adjusting member 73 has an end face 73d that defines a space together with the recess 51. When viewed from the first direction D1, the end face 73d is along at least a part of the opening in the second face 1b of the recess 51.

[0052] As shown in FIG. 14, in the present embodiment, the first adjusting member 71 has a first raised portion 74. The first raised portion 74 rises along the inner face 2b that defines the third recess 22. The first raised portion 74 fits into the third recess 22. The first adjusting member 71 and the second adjusting member 72 have a second raised portion 75. The second raised portion 75 rises along the inner face 3b that defines the second recess 32. The second raised portion 75 fits into the second recess 32. Note that the first adjusting member 71 may not have the first raised portion 74. The first adjusting member 71 and the second adjusting member 72 may not have the second raised portion 75. The main face 7a may be a plane substantially parallel to the placement surface P.

[0053] FIG. 15 is an end view of a pillow core material provided with an adjusting member according to a modification. Hereinafter, the adjusting member 7A according to the modification will be described with reference to FIG. 15. The adjusting member 7A has a first adjusting member 71A and a second adjusting member 72A instead of the first adjusting member 71 and the second adjusting member 72. Hereinafter, the differences between the above-described adjusting member 7 and the adjusting member 7A will be mainly described.

[0054] The first adjustment member 71A and the head support portion 2 are adjacent to each other in the first direction D1. The first adjustment member 71A and the cervical vertebra support portion 3 are not adjacent to each other in the first direction D1. The second adjustment member 72A and the cervical vertebra support portion 3 are adjacent to each other in the first direction D1. The second adjustment member 72A and the thoracic vertebra support portion 4 are adjacent to each other in the first direction D1. The first adjustment member 71A has a first raised portion 74. The first adjustment member 71A does not have a second raised portion 75. The second adjustment member 72A has a second raised portion 75.

[0055] The first adjustment member 71A has a concave portion 78. The concave portion 78 opens to the surface on the side opposite to the first raised portion 74. The surface where the concave portion 78 opens faces the placement surface P. The concave portion 78 is arranged along the first raised portion 74 in the first direction D1. The concave portion 78 may be recessed along the main surface 7a of the first raised portion 74. The concave portion 78 forms a space between it and the placement surface P. The second adjustment member 72A has a concave portion 77. The concave portion 77 opens to the surface on the side opposite to the second raised portion 75. The surface where the concave portion 77 opens faces the placement surface P. The concave portion 77 is arranged along the second raised portion 75 in the first direction D1. The concave portion 77 may be recessed along the main surface 7a of the second raised portion 75. The concave portion 77 forms a space between it and the placement surface P. In a cross-section orthogonal to the third direction D3, the second adjustment member 72A may exhibit an arch shape.

[0056] Next, with reference to FIG. 16, the experimental results using the embodiment of the pillow core material 1 will be described. Note that the present invention is not limited to the embodiment. In this experiment, the sleeping postures of the user using the pillow core material according to the embodiment, the sleeping postures of the user using the pillow according to the comparative example, and the cervical lordosis angle of the user sitting on a chair were compared. The cervical lordosis angle is the angle between the lower edge of the second cervical vertebra body and the lower edge of the seventh cervical vertebra body. In this experiment, the user's posture was evaluated using the cervical lordosis angle.

[0057] The cervical lordosis angle Da in the sleeping posture using the pillow core material according to the embodiment shown in Fig. 16(a) was 8.4 degrees. The pillow core material according to the embodiment is the same pillow core material as the pillow core material 1. In the pillow core material according to the embodiment, the adjustment members 7, 7A were not used. The cervical lordosis angle Db in the sleeping posture using the pillow according to the comparative example shown in Fig. 16(b) was 3.2 degrees. The pillow according to the comparative example is a pillow in which a pipe material is filled in a cover having a substantially rectangular parallelepiped shape. The cervical lordosis angle Dc in the sitting posture where the user is sitting on a chair shown in Fig. 16(c) was 8.9 degrees.

[0058] A good sleeping posture is, for example, a posture in which the S-shaped curve from the occipital region to the cervical vertebrae is similar to the S-shaped curve from the occipital region to the cervical vertebrae in the state where the user is sitting. In the S-shaped curve, the occipital region is lower than the cervical vertebrae. In one example, the difference between the lowest part of the occipital region in the S-shaped curve and the highest part of the cervical vertebrae in the S-shaped curve is about 3 cm. The cervical lordosis angle Da (8.4 degrees) in the sleeping posture using the pillow core material according to the embodiment is closer to the cervical lordosis angle Dc (8.9 degrees) in the sitting posture on a chair than the cervical lordosis angle Db (3.2 degrees) in the sleeping posture using the pillow according to the comparative example. Therefore, since the S-shaped curve from the occipital region to the cervical vertebrae in the sleeping posture is close to the S-shaped curve from the occipital region to the cervical vertebrae in the sitting state, it was confirmed that the pillow core material according to the embodiment can improve the sleeping posture from the occipital region to the cervical vertebrae of the user.

[0059] Subsequently, the effects obtained from the pillow core material 1 will be described. The pillow using the pillow core material 1 is placed so that the second surface 1b faces the placement surface P. The user U sleeping on his back is supported at the occipital region by the head support portion 2 and supported at the cervical vertebrae by the cervical vertebra support portion 3. As shown in Fig. 3, since the head support portion 2 and the cervical vertebra support portion 3 are adjacent to each other in the second direction D2 and support two points of the occipital region and the cervical vertebrae, the sleeping posture from the occipital region to the cervical vertebrae of the user U can be defined. The occipital region of the user U sleeping on his back enters into the first concave portion 21 of the head support portion 2. Therefore, the head support portion 2 can maintain the sleeping posture of the user U.

[0060] The convex portion 31 of the cervical support portion 3 supports the cervical vertebrae of the user U lying on their back. As shown in FIG. 8, the second concave portion 32 of the cervical support portion 3 forms a space between the placement surface P on which the pillow core material 1 is placed. Since this space is located opposite to the convex portion 31 in the first direction D1, the convex portion 31 that supports the cervical vertebrae deforms so as to sink into this space. According to the investigation by the present inventor, the cervical lordosis angle of Japanese people is distributed in the range of 13.9±12.3 degrees (average value±1SD). This result indicates that the shape of the cervical vertebrae varies according to individual users and there are large individual differences. The pillow core material 1 deforms so that the convex portion 31 sinks in, causing the cervical support portion 3 to deform along the cervical vertebrae of the individual user U, and enabling a good sleeping posture from the back of the head to the cervical vertebrae of the user U. As a result, the pillow core material 1 can keep the sleeping posture of the individual user U in a good state.

[0061] By correcting the sleeping posture of the user U and keeping the sleeping posture of the user U in a good state, the stiffness caused by straight neck or hunchback can be stretched by stretching the back muscles of the user U. Also, by stretching the neck muscles of the user U, wrinkles that occur on the neck of the user U can be prevented. Compared with exercise or stretching in the waking state, the stretching by the pillow core material 1 is excellent from the viewpoints of time efficiency and labor reduction. Compared with treatment by experts such as chiropractic, the stretching by the pillow core material 1 is excellent from the viewpoints of time efficiency and cost. As a result, the pillow core material 1 can make stretching a habit of the user. Furthermore, since the pressure applied from the back of the head to the cervical vertebrae of the user U is appropriately dispersed by keeping the sleeping posture of the user U in a good state, the pillow core material 1 can improve the comfort of the user U.

[0062] When viewed from the first direction D1, the convex portion 31 has the second direction D2 as the longitudinal direction and the third direction D3 as the short transverse direction. The first surface 1a of the convex portion 31 and the first surface 1a of the first concave portion 21 constitute an inclined surface that is inclined with respect to the placement surface P. The convex portion 31 is higher at a position closer to the center in the second direction D2. Thereby, the S-shaped curve from the back of the head to the cervical vertebrae of the user U can be similar to the S-shaped curve from the back of the head to the cervical vertebrae in the state where the user U is sitting.

[0063] As shown in FIG. 5, the cervical support portion 3 includes a pair of lower portions 35 adjacent to the convex portion 31 in the third direction D3. The lower portions 35 are located at the ends in the third direction D3. The lower portions 35 are the lowest in the cervical support portion 3. In the third direction D3, the distance between the pair of lower portions 35 is smaller than the maximum width of the first concave portion 21. The convex portion 31 protrudes with respect to the pair of lower portions 35, and the width of the convex portion 31 in the third direction D3 is smaller than the maximum width of the first concave portion 21. As a result, a greater pressure is applied to the portion of the user U closer to the cervical vertebrae in the third direction D3, so that the stretching of the neck by the pillow core material 1 is promoted.

[0064] As shown in FIG. 8, the third concave portion 22 of the head support portion 2 forms a space between the head support portion 2 and the placement surface P on which the pillow core material 1 is placed. The space is located opposite to the first concave portion 21 in the first direction D1. The head support portion 2 that supports the back of the head of the user U that has entered the first concave portion 21 deforms so as to sink into the space. By deforming the head support portion 2 so as to sink into the space, the user U can easily move the head and neck. By the head support portion 2 and the cervical support portion 3 deforming respectively, the pillow core material 1 can keep the sleeping posture of each user U in an even better state. Further, since the pressure applied from the back of the head to the cervical vertebrae of the user U is more appropriately dispersed, the pillow core material 1 can further improve the comfort of the user U.

[0065] As shown in FIG. 1, the groove 23 extending so as to have an annular shape separates the inner portion 24 of the annular shape and the outer portion 25 of the annular shape. Since the portion where the groove 23 extends has a thickness smaller than that of other portions, it is easily deformed. Therefore, the head support portion can more easily deform the inner portion 24 of the annular shape compared to the outer portion 25 of the annular shape. For example, for the gently curved back of the head, by the support of the outer portion 25 of the annular shape, the head support portion 2 can support the entire back of the head so that it does not sink. For example, for the sharply curved back of the head, by the inner portion 24 of the annular shape sinking, the head support portion 2 can deform along the shape of the back of the head. As a result, since this pillow core material 1 can support the position of the user U's head at an appropriate height, the sleeping posture of the user U can be maintained in an even better state. Also, since the pressure applied to the back of the user's head is more appropriately distributed, this pillow core material 1 can further improve the comfort of the user.

[0066] As shown in FIG. 8, when viewed from the first direction D1, the third recess 22 is smaller than the first recess 21. The head support portion 2 includes a portion where the third recess 22 and the first recess 21 are adjacent to each other in the first direction D1 and a portion where the third recess 22 and the first recess 21 are not adjacent to each other in the first direction D1. When viewed from the first direction D1, the thickness of the portion where the third recess 22 and the first recess 21 are adjacent to each other is smaller than the thickness of the portion where the third recess 22 and the first recess 21 are not adjacent to each other. As a result, the head support portion 2 can more easily deform the portion where the third recess 22 and the first recess 21 are adjacent to each other in the first direction D1 than the portion where the third recess 22 and the first recess 21 are not adjacent to each other in the first direction D1. For example, for the sharply curved back of the head, since the portion where the third recess 22 and the first recess 21 are adjacent to each other sinks, the head support portion 2 can deform along the shape of the back of the head. For example, for the gently curved back of the head, by the support of the portion where the third recess 22 and the first recess 21 are not adjacent to each other, the head support portion 2 can support the entire back of the head so that it does not sink.

[0067] As shown in FIG. 5, a pair of tops 33 face each other in the third direction D3 such that the cervical vertebrae can enter therebetween. Since the pair of tops 33 press the left and right muscles of the cervical vertebrae as seen from the user U lying on his or her back, the stiffness of the user U's neck can be stretched.

[0068] The portion between the pair of tops 33 is lower than the pair of tops 33. Since the portion between the pair of tops 33 is lower than the pair of tops 33, it is easier for the cervical vertebrae to enter between the pair of tops 33. As a result, the sleeping posture of the user U is likely to be stable. A groove 34 extending along the second direction D2 is formed between the pair of tops 33. When the cervical vertebrae enter the groove 34, the sleeping posture of the user U is even more likely to be stable. Further, since the pressure concentrates on the left and right muscles of the cervical vertebrae, the stretching of the stiffness of the user U's neck is promoted.

[0069] As shown in FIG. 3, the thoracic vertebra support portion 4 protruding in the second direction D2 supports the thoracic vertebrae located between the pair of scapulae of the user U, so that the pair of scapulae rotate inward so as to approach each other. As a result, the thoracic vertebra support portion 4 can keep the sleeping posture from the thoracic vertebrae to the scapulae of the user U in a good state. Further, since the pair of scapulae rotate inward, both shoulders of the user U move rearward, so that the thoracic vertebra support portion can stretch, for example, the stiffness caused by hunched shoulders.

[0070] The maximum width of the thoracic vertebra support portion 4 in the third direction D3 is shorter than the distance between the pair of scapulae of the user. The thoracic vertebra support portion 4 is lower at positions closer to the end face 4d. The first surface 1a of the thoracic vertebra support portion 4 is inclined so as to be lower closer to the end face 4d. As a result, the thoracic vertebra support portion 4 can support only the portion of the thoracic vertebrae located between the pair of scapulae so as not to support the scapulae.

[0071] As shown in FIG. 11, the cheek support portion 5 supports the cheek of the user U lying on the side. As shown in FIG. 10, the recess 51 forms a space between it and the placement surface P. In response to the user turning over from lying on the back to lying on the side, the cheek support portion 5 deforms so as to sink into the space, and thus the cheek support portion 5 can promote the turning over of the user from lying on the back to lying on the side. Further, since the opening of the end face 5c deforms, the cheek support portion 5 can appropriately disperse the pressure applied to the temporal region of the user U lying on the side.

[0072] As shown in FIG. 10, the recess 51 is defined by the inner surface 5b including the first inclined surface 56 and the second inclined surface 57. The recess 51 does not open to the end face 5f. When viewed from the first direction D1, the width of the recess 51 along the direction orthogonal to the depth direction is larger as it is closer to the end face 5c. When viewed from the first direction D1, the recess 51 is deeper in the first direction D1 at a position closer to the center of the opening of the end face 5c. When viewed from the depth direction, the recess 51 is deeper in the depth direction at a position closer to the center of the opening of the second surface 1b. As a result, the cheek support portion 5 is more likely to deform so as to sink at a position closer to the center of the opening of the second surface 1b, and thus the pressure applied to the temporal region of the user U lying on the side can be more appropriately dispersed. Further, the cheek support portion 5 can further promote the turning over of the user U from lying on the back to lying on the side.

[0073] As shown in FIG. 9, the fourth recess 52 opens to the first surface 1a of the cheek support portion 5. When viewed from the first direction D1, the fourth recess 52 has a substantially semi-circular shape whose chord faces the end face 5c. The cheekbone of the user U that has entered the fourth recess 52 is gently supported by the third inclined surface 54 that constitutes a substantially semi-circular arc and the fourth inclined surface 55 that constitutes a substantially semi-circular chord, so that the cheek support portion 5 can more appropriately disperse the pressure applied to the cheek of the user U lying on the side.

[0074] The chamfered portion 53 is a portion where the corner between the first surface 1a and the end face 5e of the cheek support portion 5 is chamfered. The surface of the chamfered portion 53 is inclined with respect to the second surface 1b and has a smaller thickness at a position closer to the end face 5e. As a result, the user U can easily grasp the chamfered portion 53.

[0075] As shown in FIG. 11, the arm holding portion 6 faces the upper arm Ua of the lying user U in the third direction D3. In the third direction D3, the end of the arm holding portion 6 is located outside the cheek support portion 5. The lying user U can hold the arm holding portion 6 between the upper arm Ua and the lower arm F by bending the elbow E along the end of the arm holding portion 6. When the elbow E is bent along the end of the arm holding portion 6, the lower arm F as seen from the lying user U is located in front of the upper arm Ua. Therefore, the arm holding portion 6 can stabilize the sleeping posture of the lying user U.

[0076] As shown in FIG. 8, the end face 2f of the head support portion 2 is an inclined surface facing the placement surface P. The end face 2f is farther from the placement surface P as it is closer to the end in the second direction D2. As shown in FIG. 9, the end face 5e of the cheek support portion 5 is an inclined surface facing the placement surface P. The end face 5e is farther from the placement surface P as it is closer to the end in the second direction D2. Therefore, the head support portion 2 is likely to deform outward in the second direction D2. As a result, it becomes easier for the user U lying on their back to raise their chin, and stretching by the pillow core material 1 is promoted.

[0077] As shown in FIG. 4, each of the end face 5c, the end face 6d, and the end face 6e is an inclined surface facing the placement surface P. The end face 5c, the end face 6d, and the end face 6e are farther from the placement surface P as they are closer to the end. A gap is formed between the end face 5c, the end face 6d, and the end face 6e and the placement surface P. The end face 6d faces the upper arm Ua of the lying user U. The upper arm Ua sunk into the bedding constituting the placement surface P is likely to enter the gap between the end face 6d and the placement surface P. The end face 5c faces the shoulder S of the lying user U. The shoulder S sunk into the bedding constituting the placement surface P is likely to enter the gap between the end face 5c and the placement surface P. The end face 6e faces the lower arm F of the lying user U. The lower arm F sunk into the bedding constituting the placement surface P is likely to enter the gap between the end face 6e and the placement surface P. Since the inclination of the end face 6c with respect to the first direction D1 as seen from the third direction D3 is smaller than the inclination of the end face 6e with respect to the first direction D1 as seen from the second direction D2, the elbow E is less likely to sink into the bedding and is easily hooked by the end face 6e and bent. As a result, the pillow core material 1 can improve the comfort of the lying user.

[0078] As shown in FIGS. 12 and 13, the adjusting member 7 has end faces 71d and 73d that define a space together with the recess 51. By arranging the adjusting member 7 between the second face 1b of the pillow core material 1 and the placement surface P, the user U can appropriately adjust the height of the pillow core material 1. Further, the user U widens the space formed by the recess 51 and the placement surface P by the end faces 71d and 73d of the adjusting member 7. As a result, the user U can adjust the amount by which the cheek support portion 5 deforms so as to sink in.

[0079] As shown in FIG. 15, the adjusting member 7A has a first raised portion 74 that rises along the second face 1b in the third recess 22, and a recess 78 arranged along the first raised portion 74 in the first direction D1. Since a space is formed between the recess 78 and the placement surface P, the user U can adjust the height of the pillow core material 1 using the adjusting member 7 and appropriately adjust the size of the space adjacent to the third recess 22 in the first direction D1. As a result, the user U can adjust the amount by which the head support portion 2 deforms so as to sink in. Further, since the first raised portion 74 enters the third recess 22, the adjusting members 7 and 7A can suppress the displacement between the second face 1b of the pillow core material 1 and the adjusting members 7 and 7A. Since the second raised portion 75 enters the second recess 32, the adjusting members 7 and 7A can suppress the displacement between the second face 1b of the pillow core material 1 and the adjusting members 7 and 7A.

[0080] The embodiments of the pillow core material according to the present disclosure have been described above. However, the pillow core material according to the present disclosure is not limited to the above-described embodiments, and may be modified or applied to other things without changing the gist described in the claims. That is, the shape, size, material, number, and arrangement mode of each part of the pillow core material according to the present disclosure can be variously modified without changing the gist described in the claims.

[0081] FIG. 17 is a plan view showing the pillow core material 1A according to the first modified example. As shown in FIG. 17, the pillow core material 1A does not include the arm holding portion 6. In this case, the end faces 5c and 5e are continuous. In the second direction D2, the end of the cheek support portion 5 is located behind the end of the thoracic vertebra support portion 4.

[0082] FIG. 18 is a plan view showing the pillow core material 1B according to the second modified example. As shown in FIG. 18, the pillow core material 1B does not include the arm holding portion 6 and the thoracic vertebra support portion 4. In this case, the cervical vertebra support portion 3 protrudes from the head support portion 2 in the second direction D2. The cervical vertebra support portion 3 protrudes from the cheek support portion 5 in the second direction D2. The cervical vertebra support portion 3 has a second concave portion 32 (not shown). The cervical vertebra support portion 3 includes an end face 3c in the second direction D2 and an end face 3d in the third direction D3. The end face 3c and the end face 3d are continuous. The end face 3d and the end face 5c are continuous. The end of the cervical vertebra support portion 3 in the second direction D2 and the end of the cheek support portion 5 in the second direction D2 face each other in the third direction D3 with a space therebetween. When viewed from the first direction D1, the end faces 3d and 5c are curved such that the portion between the end face 3d and the end face 5c is recessed rearward.

[0083] FIG. 19 is a plan view showing the pillow core material 1C according to the third modified example. As shown in FIG. 19, the pillow core material 1C does not include the arm holding portion 6, the thoracic vertebra support portion 4, and the cheek support portion 5. In this case, the cervical vertebra support portion 3 protrudes from the head support portion 2 in the second direction D2. The cervical vertebra support portion 3 has a second concave portion 32 (not shown). The head support portion 2 includes an end face 2e in the third direction D3. The end face 3d and the end face 2e are continuous. When viewed from the first direction D1, the end face 3d is curved so as to be recessed inward.

[0084] The head support portion 2 may not have at least one of the first concave portion 21 and the third concave portion 22. The head support portion 2 may not have both the first concave portion 21 and the third concave portion 22. The head support portion 2 may be made of a flexible material that is softer than other portions. The head support portion 2 may have a through hole penetrating in the first direction D1.

[0085] The protruding end in front of the pair of arm holders 6 and the protruding end in front of the thoracic vertebra support part 4 may be connected by a plate-like member along the second surface 1b. In this case, a depression is formed between the pair of arm holders 6 and the thoracic vertebra support part 4.

[0086] The depression 51 may be included in both the cheek support part 5 and the arm holder 6. The depression 51 may open to both the end face 5c on the side of the cervical vertebra support part 3 in the second direction D2 of the cheek support part 5 and the second surface 1b of the cheek support part 5, and may also open to both the end face 6d on the side of the cervical vertebra support part 3 in the third direction D3 of the arm holder 6 and the second surface 1b of the arm holder 6. The opening of the end face 5c and the opening of the end face 6d may be continuous. In a cross-section along the first direction D1, the inner surface 5b may be farther away from the placement surface P as it is closer to the end face 6d. In the configuration where the depression 51 is included in both the cheek support part 5 and the arm holder 6, since the depression 51 opens to both the end face 5c and the end face 6d, the cheek support part 5 is more likely to deform so as to sink toward the space between the depression 51 and the placement surface P. Therefore, the configuration in which the depression 51 is included in both the cheek support part 5 and the arm holder 6 can further promote the user U to turn over from lying on the back to lying on the side.

[0087] The adjustment member 7 may have an end face that defines a space together with the second recess 32. The adjustment member 7 may have an end face that defines a space together with the third recess 22. The adjustment member 7A may have only the first raised portion 74 and the recess 78. The adjustment member 7A may have only the second raised portion 75 and the recess 77.

Explanation of Reference Numerals

[0088] 1, 1A, 1B, 1C… Pillow core material, 1a… First side, 1b… Second side, 2… Head support part, 21… First concave part, 22… Third concave part, 23… Groove, 24… Part, 25… Part, 2a, 2b… Inner surface, 2e… End face, 2f… End face, 3… Cervical vertebra support part, 31… Convex part, 32… Second concave part, 33… Top part, 34… Groove, 3b… Inner surface, 3c… End face, 3d… End face, 4… Thoracic vertebra support part, 4c… End face, 4d… End face, 5… Cheek support part, 51… Depression, 52… Fourth concave part, 53… Chamfered part, 54… Third inclined surface, 55… Fourth inclined surface, 56… First inclined surface, 57… Second inclined surface, 5b… Inner surface, 5c… End face, 5e… End face, 5f… End face, 6… Wrist holding part, 6c… End face, 6d… End face, 6e… End face, 7, 7A… Adjusting member, 7a… Main surface, 71… First adjusting member, 71d… End face, 71A… First adjusting member, 72… Second adjusting member, 72A… Second adjusting member, 73… Third adjusting member, 73d… End face, 74… First raised part, 75… Second raised part, 77, 78… Concave part, A… Wrist, E… Elbow, F… Forearm, P… Placing surface, S… Shoulder, U… User, Ua… Upper arm, D1… First direction, D2… Second direction, D3… Third direction.

Claims

1. A pillow core material made of a flexible material, having a first surface facing the user and a second surface facing opposite to the first surface in a first direction, comprising: a head support portion for supporting the back of the user's head; a cervical vertebra support portion for supporting the user's cervical vertebrae and adjacent to the head support portion in a second direction intersecting the first direction; wherein: the head support portion has a first recess that opens on the first surface and into which the back of the head fits; the cervical vertebra support portion: includes a convex portion that includes the first surface and protrudes in the first direction; has a second recess that opens on the second surface and is arranged along the first direction with the convex portion; A pillow core material.

2. The head support portion has a third recess that opens on the second surface and is arranged along the first direction with the first recess. The pillow core material according to Claim 1.

3. The head support portion has a groove that opens on an inner surface defining the first recess, and the groove extends so as to form an annular shape. The pillow core material according to Claim 2.

4. The convex portion includes a pair of tops facing each other in a third direction intersecting both the first direction and the second direction, and between the pair of tops, the cervical vertebrae can fit in. The pillow core material according to Claim 1.

5. further comprising a thoracic vertebra support portion adjacent to the cervical vertebra support portion in the second direction and supporting the user's thoracic vertebrae, wherein the thoracic vertebra support portion protrudes from the cervical vertebra support portion in the second direction. The pillow core material according to any one of Claims 1 to 4.

6. further comprising a pair of cheek support portions for supporting the cheeks of the user lying on the side, wherein in a third direction intersecting both the first direction and the second direction, the head support portion is located between the pair of cheek support portions, and each of the pair of cheek support portions has a depression that opens on both an end surface on the cervical vertebra support portion side in the second direction and the second surface. The pillow core material according to Claim 2 or 3.

7. further comprising a pair of arm holding portions protruding from the pair of cheek support portions in the second direction so as to face the upper arms of the user lying on the side in the third direction, wherein in the third direction, ends of the pair of arm holding portions are located outside ends of the pair of cheek support portions. The pillow core material according to Claim 6.

8. further comprising an adjustment member having a plate shape, wherein the adjustment member includes a main surface facing the second surface and an end surface intersecting the main surface, and at least a part of the end surface defines a space together with at least one of the second recess, the third recess, and the depression. The pillow core material according to claim 6.

9. Further comprising an adjusting member having a plate shape, The adjusting member is, A raised portion that rises along the inner surface defining the third recess, An opening on the surface opposite to the raised portion, and a recess aligned with the raised portion along the first direction, Having, The pillow core material according to claim 2 or 3.

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