Vehicle seat

Abstract

To provide a vehicle seat capable of suppressing effectively, motion sickness of an occupant.SOLUTION: A headrest comprises: a first constitution part 25 which has on its front surface, a recess 27 into which a supported part can enter, the supported part being a part of the head of an occupant and being a portion corresponding to an occipital bone, and is formed of a rigid urethane; and a second constitution part which is formed of a soft urethane being softer than the rigid urethane, and is provided on the recess and is deformed by the supported part. A part of the first constitution part being a bottom face of the recess, is a left and right pair of head support planes which supports the supported part and is connected on a linear connection portion, and a first angle being an angle formed by cross sections of left and right head support planes which are cut in a plane orthogonal to the connection portion, is in a range of 37.2° to 143°, and in view from a seat lateral direction, a second angle being an angle formed by a direction orthogonal to the connection portion and the seat cross direction, is set in a range of 12.8° to 68.7°.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a vehicle seat.

Background Art

[0002] The following Patent Document 1 discloses a vehicle seat including a seat cushion that supports the buttocks of a seated occupant, a seat back that supports the back of the seated occupant, and a headrest that supports the head of the seated occupant. This headrest includes a metal stay, a rigid foam provided around the stay, and a soft foam fixed to the front surface of the rigid foam. The head of the seated occupant on the seat is supported by the soft foam.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The vehicle seat described in the above Patent Document 1 has room for improvement in effectively suppressing motion sickness of the occupant.

[0005] In consideration of the above facts, an object of the present invention is to obtain a vehicle seat that can effectively suppress motion sickness of the occupant.

Means for Solving the Problems

[0006] The vehicle seat according to the first aspect includes a seat cushion that supports the buttocks of the seated occupant, a seat back that supports the back of the seated occupant, and a headrest that supports the head of the seated occupant. The headrest has a first component made of rigid urethane, in which a concave portion into which a supported portion, which is a part of the head of the seated occupant and corresponds to the occipital bone, can enter is formed on the front surface. The headrest also has a second component made of soft urethane having a lower hardness than the rigid urethane, which is provided in the concave portion and is deformed by the supported portion. A part of the first component, which is the bottom surface of the concave portion, supports the supported portion via the deformed second component and is a pair of left and right head support surfaces that are connected to each other at a linear connection portion. A first angle, which is the angle formed by the cross-sections of the left and right head support surfaces cut by a plane orthogonal to the connection portion, is set in the range of 37.2° to 143°. When viewed in the left-right direction of the seat, a second angle, which is the angle formed by the direction orthogonal to the connection portion and the front-rear direction of the seat, is set in the range of 12.8° to 68.7°.

[0007] In the vehicle seat according to the first aspect, when the seated occupant sits on the seat, a supported portion, which is a part of the head of the seated occupant and corresponds to the occipital bone, approaches the first component while deforming the second component. At this time, the supported portion is supported by the left and right head support surfaces of the first component via the deformed second component. Thereby, the rocking of the head of the seated occupant is suppressed, and the motion sickness of the seated occupant is suppressed.

[0008] In the vehicle seat according to the first aspect, in the cross-section of the left and right head support surfaces cut by a plane orthogonal to the connection portion, a first angle, which is the angle formed by the left and right head support surfaces, is set in the range of 37.2° to 143°. Further, when viewed in the left-right direction of the seat, a second angle, which is the angle formed by the direction orthogonal to the connection portion and the front-rear direction of the seat, is set in the range of 12.8° to 68.7°. Thereby, compared with a configuration in which the first angle and the second angle are set outside the above ranges, the motion sickness of the seated occupant is more effectively suppressed.

[0009] The vehicle seat according to the second aspect is the vehicle seat according to the first aspect, wherein the first angle is set in the range of 70.5° to 124.5°, and the second angle is set in the range of 31.1° to 56.6°.

[0010] In the vehicle seat according to the second aspect, the first angle is set in the range of 70.5° to 124.5°, and the second angle is set in the range of 31.1° to 56.6°. Thereby, compared with the configuration in which the first angle and the second angle are set outside the above ranges, motion sickness of the seated occupant is more effectively suppressed.

[0011] The vehicle seat according to the third aspect is the vehicle seat according to the first aspect or the second aspect, wherein the head support surface is a flat surface.

[0012] In the vehicle seat according to the third aspect, motion sickness of a plurality of seated occupants having heads (supported portions) of various sizes is effectively suppressed.

Advantages of the Invention

[0013] The vehicle seat according to the present invention has an excellent effect of effectively suppressing motion sickness of the occupant.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Mode for Carrying Out the Invention

[0015] Hereinafter, a vehicle seat 10 (hereinafter referred to as seat 10) according to an embodiment of the present invention will be described with reference to the accompanying drawings. Note that an arrow FR appropriately shown in each figure indicates the front direction of the seat, an arrow UP indicates the upward direction of the seat, and an arrow LH indicates the left side in the left - right direction (seat width direction) of the seat. Hereinafter, when simply using the directions of front - rear, left - right, and up - down for explanation, it indicates the front - rear in the seat front - rear direction, the left - right in the seat left - right direction, and the up - down in the seat up - down direction.

[0016] The seat 10 shown in FIG. 1 is provided on the floor surface of the passenger compartment of a vehicle (not shown). The seat 10 includes a seat cushion 11 supported on the floor surface via a slide rail device (not shown), a seat back 15 having a lower end connected to the rear end of the seat cushion 11, and a headrest 20 supported at the upper end of the seat back 15. The seat cushion 11 supports the buttocks of the seated occupant P (see FIGS. 6 to 8) from below. The seat back 15 supports the back of the seated occupant P from behind. The headrest 20 supports the head P1 of the seated occupant from behind. Note that the seat back 15 is reclinable in the front - rear direction with respect to the seat cushion 11.

[0017] The headrest 20 has a headrest frame 21, a first component 25, a second component 45, and a cover member (not shown) described later.

[0018] As shown in FIG. 1, a headrest frame 21 is provided inside the headrest 20. The headrest frame 21 is composed of metal pipes. The front shape of the headrest frame 21 is substantially U-shaped. The headrest frame 21 includes an upper end component 22 extending in the left-right direction and a pair of left and right side components 23 extending downward from both left and right ends of the upper end component 22. The lower end portions of the left and right side components 23 are fixed to the upper end portion of the seat back 15. Note that the lower end portions of the left and right side components 23 may be slidably supported in the extending direction of the side components 23 by the upper end portion of the seat back 15. When a center line AX passing through the center of the headrest 20 in the left-right direction and extending in the up-down direction is defined, the headrest 20 is symmetric about the center line AX in a front view. In the following description, it is assumed that the left and right side components 23 are parallel to the vertical direction. That is, it is assumed that the up-down direction of the seat coincides with the vertical direction.

[0019] The headrest 20 has a first component 25 located around the headrest frame 21 and fixed to the headrest frame 21. The first component 25 is an integrally molded product made of rigid urethane. The hardness of this rigid urethane is, for example, 20 N (Newton). For example, the first component 25 is manufactured using a mold (not shown).

[0020] A recess 27 is formed on the front surface 26 of the first component 25. The recess 27 is symmetric about the center line AX in a front view. The bottom surface (inner surface) of the recess 27 includes a pair of left and right side surfaces 30, a pair of left and right upper component surfaces 35, and a pair of left and right head support surfaces 40. The left and right side surfaces 30 are planes orthogonal to the left-right direction. However, the left and right side surfaces 30 may be curved surfaces. As shown in FIG. 3, the lower edge portion 31 of each side surface 30 is inclined in the front-rear direction and the up-down direction in a side view.

[0021] The upper left and right configuration surfaces 35 form the upper part of the bottom surface of the recess 27. In a front view, the upper left and right configuration surfaces 35 are symmetric about the center line AX. The lower edge 36 of each upper configuration surface 35 is inclined with respect to the left-right direction and the up-down direction in a front view. Further, as shown in FIG. 4, the upper left and right configuration surfaces 35 are inclined with respect to each other in a plan view. As shown in FIG. 4, the front-back distance (the maximum depth of the recess 27) between the connection part of the upper left and right configuration surfaces 35 and the front surface 26 of the first configuration part 25 is DP1. The distance DP1 is preferably 50 mm or more.

[0022] The left and right head support surfaces 40 form the lower part of the bottom surface of the recess 27. The left and right head support surfaces 40 are flat. As shown in FIG. 1, in a front view, the left and right head support surfaces 40 are symmetric about the center line AX. Further, the shape of each of the left and right head support surfaces 40 when viewed from a direction orthogonal to each head support surface 40 is a substantially parallelogram. The right edge of the left head support surface 40 and the left edge of the right head support surface 40 are connected to each other via a linear connection part 41. The left edge of the left head support surface 40 and the right edge of the right head support surface 40 are respectively connected to the lower edges 31 of the left and right side surfaces 30. The upper edges of the left and right head support surfaces 40 are respectively connected to the lower edges 36 of the upper left and right configuration surfaces 35.

[0023] As shown in FIG. 5, when the left and right head support surfaces 40 are cut along the 5-5 arrow line in FIG. 2, the cut surfaces of the left and right head support surfaces 40 intersect at a first angle θ1. In other words, the angle formed by the left and right head support surfaces 40 cut by a plane CS (see FIG. 3) orthogonal to the connection part 41 is the first angle θ1.

[0024] As shown in FIG. 3, when the headrest 20 is viewed along the left-right direction, the angle formed by the direction PD orthogonal to the connection part 41 and the front-back direction of the seat (horizontal plane HS) is the second angle θ2.

[0025] As shown in FIGS. 1 and 2, the headrest 20 has a second component part 45. The shape of the second component part 45 is substantially the same as the shape of the concave part 27 of the first component part 25. The second component part 45 is fitted into the concave part 27. Therefore, the overall shape of the integrated object composed of the first component part 25 and the second component part 45 is substantially a rectangular parallelepiped shape. The second component part 45 is an integrally molded product made of soft urethane. The hardness of this soft urethane is smaller than the hardness of the above-mentioned hard urethane, for example, the hardness is 4 N (Newton) or less. For example, the second component part 45 is manufactured using a mold (not shown).

[0026] Although not shown, a cover member made of a flexible material is attached to the outer peripheral surface of the integrated first component part 25 and second component part 45. By this cover member, the integrated state of the first component part 25 and the second component part 45 is maintained.

[0027] Here, when the seated occupant P sits on the seat 10, as shown in FIGS. 6 to 8, the supported part PS, which is the part corresponding to the occipital bone P2 at the head P1 of the seated occupant P, approaches the left and right head support surfaces 40 of the first component part 25 while deforming the cover member and the second component part 45 (while being recessed backward). Further, in a side view of the seat, the left and right head support surfaces 40 overlap the supported part PS of the seated occupant P in the left-right direction. Further, the shape and dimensions of the left and right head support surfaces 40 are set so that the left and right head support surfaces 40 support only the part behind the mastoid process P3 at the head P1 of the seated occupant P.

[0028] Further, when the supported portion PS is disposed between the left and right head support surfaces 40 and is supported by the left and right head support surfaces 40 via the deformed cover member and the second component portion 45, the pressure received by the right side portion P4R of the supported portion PS from the right head support surface 40 via the cover member and the second component portion 45 becomes high, and the pressure received by the left side portion P4L of the supported portion PS from the left head support surface 40 via the cover member and the second component portion 45 becomes high. Thus, the angular ranges of the first angle θ1 and the second angle θ2 are set. The right side portion P4R and the left side portion P4L respectively correspond to both left and right side portions of the lower end of the occipital bone P2. The lower end of the occipital bone P2 is the portion below the upper item line P5 in the occipital bone P2. Further, in a state where the head P1 of the seated occupant P faces forward, the right side portion P4R and the left side portion P4L are located at the same height. The lateral interval W between the right side portion P4R and the left side portion P4L depends on the size of the head of the seated occupant P, but may generally be assumed to be approximately 90 mm to 120 mm. Assuming this interval W and setting the shapes and dimensions of the pair of left and right head support surfaces 40, it becomes possible to accommodate seated occupants P of almost all body builds of adult men and adult women.

[0029] (Operation and Effect of the Present Embodiment) Next, the operation and effect of the present embodiment will be described.

[0030] In the seat 10 of the present embodiment described above, the buttocks, back, and head P1 of the seated occupant P are supported by the seat cushion 11, the seat back 15, and the headrest 20. Further, the supported portion PS of the head P1 of the seated occupant P approaches the first component portion 25 while deforming the cover member and the second component portion 45. At this time, the supported portion PS is supported by the left and right head support surfaces 40 of the first component portion 25 via the deformed cover member and the second component portion 45. More specifically, the supported portion PS is supported from the left and right in the seat lateral direction by the left and right head support surfaces 40 and is supported from the rear side of the seat in the forward and obliquely upward directions of the seat. Thereby, the rocking of the head P1 of the seated occupant P is suppressed, and the motion sickness of the seated occupant P1 is suppressed.

[0031] Furthermore, since the portion where the head support surface 40 is formed is not movable, the first component 25 (headrest 20) can be manufactured at low cost.

[0032] Furthermore, since the portion where the head support surface 40 is formed is covered by the second component 45, it is difficult for unevenness to form on the front surface of the headrest 20 (cover member). In other words, the design property of the headrest 20 is hardly impaired.

[0033] Furthermore, by setting the distance DP1 in the front-rear direction between the connection portion of the left and right upper configuration surfaces 35 and the front surface 26 of the first component 25 to 50 mm or more, before the supported portion PS is supported by the left and right head support surfaces 40 via the deformed cover member and the second component 45, it is difficult for the head P1 to be supported by the left and right upper configuration surfaces 35 via the deformed cover member and the second component 45. That is, when the distance DP1 is set to 50 mm or more, the distance between the supported portion PS and the left and right head support surfaces 40 is less likely to be longer than the appropriate distance, and the possibility that the supported portion PS is not supported by the left and right head support surfaces 40 is reduced.

[0034] By the way, in recent years, with the advancement of vehicle automation, there has been an increasing concern that motion sickness during vehicle automation may become more serious. This motion sickness is known to occur due to a sensory conflict between the vestibular organ and vision when the head of the occupant sways. In addition to this, it is known that this motion sickness can be reduced by reducing the amount of sensory deviation between the vestibular organ and vision of the occupant. Therefore, in order to suppress the swaying of the head, which is the cause of motion sickness, it is important to set the first angle θ1 and the second angle θ2 of the left and right head support surfaces 40 to appropriate sizes. Therefore, the applicant of the present application conducted the following tests in order to obtain the ranges of the first angle θ1 and the second angle θ2 that enable the seated occupant P to use the seat 10 without discomfort.

[0035] In this test, the seat 10 is repeatedly vibrated left and right between a position inclined 10° to the left and a position inclined 10° to the right with respect to the vertical direction. The frequency of this vibration is 0.1 Hz. Also, this test was conducted in the upright posture shown in FIG. 9. Note that the upright posture means a riding posture in which the seated occupant P can visually recognize the front of the vehicle. As an example, in this test, the reclining angle θs of the seat back 15 was set to 23.2°. The dashed line L1 shown in FIG. 9 is the reference line for the reclining angle θs. This dashed line L1 corresponds to the backrest surface that constitutes the seat back 15. Here, the backrest surface is the central portion in the seat width direction of the surface that supports the waist of the seated occupant P from the rear side of the seat in the seat back 15. The reclining angle θs is measured with the occupant not seated on the seat 10.

[0036] There were 10 subjects who underwent this test, and the BMIs representing the physiques of the 10 subjects were 18.7 to 29.4. Note that BMI (Body Mass Index) is a physique index calculated from weight and height, and when the weight is M (kg) and the height is L (m), it is the value calculated by M / (L 2 )

[0037] And in this test, the ranges of the first angle θ1 and the second angle θ2 when each of the 10 subjects felt the following (1), (2), and (3) were measured. (1) The support of the head P1 by the pair of left and right head support surfaces 40 is optimal. (2) The support of the head P1 by the pair of left and right head support surfaces 40 is appropriate and not uncomfortable. (3) The support of the head P1 by the pair of left and right head support surfaces 40 is hardly obtained.

[0038] Figure 10 shows a graph in which the first angle θ1 and the second angle θ2 when each of the 10 subjects felt the above (1) to (3) are plotted, and the ranges of the first angle θ1 and the second angle θ2 when the 10 subjects felt the above (1) were determined as the "optimal range". Also, the ranges of the first angle θ1 and the second angle θ2 when the 10 subjects felt the above (2) were determined as the "acceptable range". In the graph shown in Figure 10, the optimal range is enclosed by line L3, and the acceptable range is enclosed by line L4. Here, the square plots are the positions evaluated by each subject as the upper limit angles (beyond which the first and second angles are not supported to widen), the round plots are the positions evaluated by each subject as the optimal angles, and the triangular plots are the lower limit angles (beyond which the subjects feel uncomfortable when the first and second angles close). The outside of the range enclosed by the acceptable range line L4 is the range where the 10 subjects feel the above (3). Here, the optimal range and the acceptable range are in the range of -3σ to +3σ with respect to the average values of the first angle θ1 and the second angle θ2 measured in the above test. Note that σ is the standard deviation obtained from the first angle θ1 and the second angle θ2 measured in the above test.

[0039] Summarizing the results of the above tests, the optimal range and the acceptable range of the first angle θ1 and the second angle θ2 are as shown in Table 1 below.

Table 1

[0040] From the above, by setting the first angle θ1 in the range of 37.2° to 143° and the second angle θ2 in the range of 12.8° to 68.7°, it becomes difficult for the seated occupant P whose head P1 is supported by the left and right head support surfaces 40 to feel discomfort. Thereby, the vehicle sickness of the seated occupant P can be effectively suppressed.

[0041] In addition, by setting the first angle θ1 in the range of 70.5° to 124.5° and setting the second angle θ2 in the range of 31.1° to 56.6°, it becomes more difficult for the seated occupant P whose head P1 is supported by the pair of left and right head support surfaces 40 to feel discomfort. As a result, the vehicle sickness of the seated occupant P can be more effectively suppressed.

[0042] Furthermore, the left and right head support surfaces 40 of the first component 25 are both flat. Therefore, the left and right head support surfaces 40 can support heads (supported parts) of various sizes (shapes), and it is difficult to give discomfort to the seated occupant whose head is supported. Therefore, the seat 10 can effectively suppress the vehicle sickness of a plurality of seated occupants having heads (supported parts) of various sizes. Incidentally, if the head support surface 40 is formed by a curved surface, when this head support surface 40 supports a head (supported part) of a specific size (shape), the seated occupant whose head is supported may hardly feel discomfort. However, when the head support surface 40 is formed by a curved surface, when the head support surface 40 supports a head (supported part) of another size (shape), the possibility that the seated occupant whose head is supported feels discomfort is greater than when the head support surface 40 is flat.

[0043] As described above, the embodiments of the present invention have been described, but the present invention is not limited to these embodiments.

[0044] The head support surface 40 does not have to be flat.

[0045] The first component 25 may be configured such that the left and right upper component surfaces 35 are arranged in a straight line in a plan view. In this case, the distance in the front-rear direction (the depth of the concave portion 27) between the upper component surface 35 and the front surface 26 of the first component 25 is preferably 50 mm or more.

Explanation of reference numerals

[0046] 10 Vehicle seat (seat) 11 Seat cushion 15 Seat back 20 Headrest 25 First component 26 Front 27 Concave portion 40 Head support surface 41 Connection part 45 Second component θ1 First angle θ2 Second angle P Seated passenger PS Supported part

Claims

1. A seat cushion that supports the buttocks of a seated occupant, a seat back that supports the back of the seated occupant, a headrest that supports the head of the seated occupant, comprising: the headrest includes a first component made of rigid urethane, having a recess formed in the front surface thereof into which a supported portion, which is a part of the head of the seated occupant and corresponds to the occipital bone, can enter; a second component made of soft urethane having a lower hardness than the rigid urethane, provided in the recess, and deformed by the supported portion; comprising: a pair of left and right head support surfaces, which are part of the first component and are the bottom surface of the recess, support the supported portion via the deformed second component, and are connected to each other at a linear connection site; a first angle, which is the angle formed by the cross-sections of the left and right head support surfaces cut by a plane orthogonal to the connection site, is set in the range of 37.2° to 143°; a vehicle seat in which a second angle, which is the angle formed by the direction orthogonal to the connection site and the front-rear direction of the seat when viewed in the left-right direction of the seat, is set in the range of 12.8° to 68.7°.

2. The vehicle seat according to claim 1, wherein the first angle is set in the range of 70.5° to 124.5°, and the second angle is set in the range of 31.1° to 56.6°.

3. The vehicle seat according to claim 1 or claim 2, wherein the head support surface is a flat surface.

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