Headrest stay structure

Abstract

To obtain a headrest stay structure which can enhance robustness.SOLUTION: A headrest stay structure includes: a headrest stay body 12 which has one end connected to a seat back of a vehicular seat and the other end mounted with a headrest body 32 thereon; and a flat section 20 which is provided in the headrest stay body 12, has a flat surface 20A in a longitudinal direction of the seat back, and is formed so that the flat surface 20A is substantially parallel to a straight line D2 passing a hip point of a human body dummy 50 and a center of gravity G of a head 54 and a perpendicular P from the straight line D2 passing the center of gravity G of the head 54 passes the flat surface 20A in a side view of the vehicular seat when the head 54 of the human body dummy 50 comes into contact with the headrest body 32 during a rear-end collision test to be performed by seating the human body dummy 50 on the vehicular seat.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a headrest stay structure. [Background technology]

[0002] Patent Document 1 discloses a headrest that is capable of absorbing impact energy during a collision by providing a deformation portion in which a portion of the headrest stay is flattened and plastically deformable. In this headrest, a cover is provided on the deformation portion to avoid danger caused by the deformation portion becoming a protrusion when an impact is received. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 6-64548 Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, rear-end collision test results have become increasingly important in assessments in recent years. To consistently achieve these targets, it is necessary to ensure that the dummy's head contacts the target position of the headrest stay. However, because conventional headrest stays are often cylindrical, they make point or line contact with the dummy's head. Therefore, depending on the behavior of the dummy, the contact position may shift, making it difficult to stably contact the dummy's head with the target position of the headrest stay, potentially reducing robustness. In the headrest described in Patent Document 1, the deforming portions are provided on the side pieces extending vertically at both left and right ends, or in the center of the upper portion, but the layout relationship between the headrest stay and the head of a person seated in the seat is not mentioned. Therefore, there is room for improvement in terms of improving robustness.

[0005] In consideration of the above, an object of the present invention is to provide a headrest stay structure that can improve robustness. [Means for solving the problem]

[0006] A headrest stay structure of a first aspect of the present invention comprises: a headrest stay main body having one end connected to a seat back of a vehicle seat and having a headrest main body attached to the other end; and a flat portion provided on the headrest stay main body, having a flat surface in the fore-and-aft direction of the seat back, the flat portion being formed so that, when the head of the dummy is brought into contact with the headrest main body during a rear-end collision test conducted with the dummy seated in the vehicle seat, the flat surface is approximately parallel to a line passing through the hip point of the dummy and the center of gravity of the head, and a perpendicular line from the line passing through the center of gravity of the head passes through the flat surface, in a side view of the vehicle seat.

[0007] In the headrest stay structure of the first aspect, the flat portion provided on the headrest stay main body has a flat surface in the front-to-rear direction of the seat back. Therefore, the contact between the headrest stay main body and the head of the anthropomorphic dummy can be surface contact, which increases the contact area with the head of the anthropomorphic dummy compared to point contact or line contact, and allows the head of the anthropomorphic dummy to stably abut on the flat portion regardless of the behavior of the anthropomorphic dummy. Note that "contact between the headrest stay main body and the head of the anthropomorphic dummy" includes contact between the headrest stay main body and the head of the anthropomorphic dummy via, for example, a trim cover constituting the headrest main body or a cushioning material disposed inside the trim cover.

[0008] Furthermore, in the headrest stay structure of the first aspect, the flat portion is formed so that, when the head of the anthropomorphic dummy comes into contact with the headrest during a rear-end collision test performed with an anthropomorphic dummy seated in the vehicle seat, the flat surface of the flat portion is substantially parallel to a line passing through the hip point of the anthropomorphic dummy and the center of gravity of the anthropomorphic dummy's head, in a side view of the vehicle seat, and a perpendicular line from the line passing through the center of gravity of the head passes through the flat surface. As a result, when the head of the anthropomorphic dummy comes into contact with the headrest main body during the rear-end collision test, the flat surface of the flat portion faces the head of the anthropomorphic dummy, allowing the head of the anthropomorphic dummy to stably abut against the flat surface of the flat portion. As described above, by allowing the head of the anthropomorphic dummy to stably abut against the flat portion, robustness can be improved without using additional parts made of, for example, EPP (expanded polypropylene) or the like.

[0009] In the headrest stay structure of the second aspect of the present invention, when the headrest main body is positioned at a height intermediate between the lower limit position and the upper limit position of the height adjustable range in the first aspect, the flat portion is provided at a height position that includes the height of the center of gravity of the head at the time of contact.

[0010] Here, "a flat portion provided at a height position that includes the height of the center of gravity of the head" means that the height of the center of gravity of the head is included in the height direction of the flat portion.

[0011] In the headrest stay structure of the second aspect, when the headrest main body is positioned at a height intermediate between the lower limit position and the upper limit position of the height adjustable range, the flat portion is provided at a height position that includes the height of the center of gravity of the dummy's head when it comes into contact with the headrest main body. As a result, when the dummy's head comes into contact with the headrest main body during a rear-end collision test, the height direction of the flat portion includes the height of the center of gravity of the dummy's head, allowing the dummy's head to stably abut on the flat portion.

[0012] A headrest stay structure of a third aspect of the present invention is the headrest stay structure of the first or second aspect, wherein the headrest stay main body includes a pair of vertical stays, one end of which is connected to the seat back, and a horizontal stay connecting the pair of vertical stays, and the flat portion is configured to include at least a part of the horizontal stay.

[0013] In the headrest stay structure of the third aspect of the present invention, the flat portion is configured to include at least a portion of the horizontal stay, so that the head of the dummy can be stably abutted against the flat portion even when the head of the dummy moves left and right.

[0014] The headrest stay structure of a fourth aspect of the present invention is the headrest stay structure of the third aspect, wherein the flat portion includes both the horizontal stays and the vertical stays.

[0015] In the headrest stay structure of the fourth aspect of the present invention, the flat portion is configured to include both horizontal stays and vertical stays, so that the head of the dummy can be stably abutted against the flat portion even when the head of the dummy moves left and right and up and down. [Effects of the Invention]

[0016] As described above, according to the headrest stay structure of the first aspect, the head of the dummy can be stably abutted against the flat portion, thereby increasing robustness without using additional parts made of, for example, EPP.

[0017] According to the headrest stay structure of the second aspect, the head of the anthropomorphic dummy can be brought into more stable contact with the flat portion.

[0018] According to the headrest stay structure of the third aspect, the head of the dummy can be brought into stable contact with the flat portion even when the head of the dummy moves in the left-right direction.

[0019] According to the headrest stay structure of the fourth aspect, the head of the anthropomorphic dummy can be brought into stable contact with the flat portion even when the head of the anthropomorphic dummy moves left and right and up and down. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 2 is a schematic perspective view of a main part of a headrest stay to which the headrest stay structure according to the first embodiment is applied. [Figure 2] FIG. 2 is a side view of a headrest including the headrest stay of FIG. [Figure 3] FIG. 3 is a side view of a vehicle seat equipped with the headrest of FIG. 2. [Figure 4] FIG. 1 is a schematic side view of an anthropomorphic dummy used in a rear impact test. [Figure 5] 1 is a schematic side view of an anthropomorphic dummy seated in a vehicle seat; [Figure 6] FIG. 6 is an enlarged side view of the main part of FIG. 5. [Figure 7] FIG. 10 is a schematic perspective view of a main part of a headrest stay to which a headrest stay structure according to a second embodiment is applied. [Figure 8] 9 is an enlarged side view of a main part of a human dummy seated on a vehicle seat in which the headrest stay of FIG. 8 is used. DETAILED DESCRIPTION OF THE INVENTION

[0021] First Embodiment Hereinafter, a headrest stay 10 to which the headrest stay structure according to the first embodiment is applied will be described with reference to Figs. 1 to 6. Note that in each drawing, some reference numerals may be omitted to make the drawings easier to see. Also, the arrows FR and UP shown as appropriate in each drawing indicate the front and the top, respectively, of the seat back 44 to which the headrest 30 provided with the headrest stay 10 is attached. Hereinafter, when the front-rear and top-bottom directions are used in the description, they will indicate the directions relative to the headrest stay 10 and the headrest 30 attached to the seat back 44.

[0022] As shown in Fig. 1, a headrest stay 10 to which the headrest stay structure according to the first embodiment is applied includes a headrest stay main body 12. The headrest stay main body 12 is manufactured by bending a metal pipe, for example, and has a generally inverted U-shape when viewed in the front-to-rear direction. Specifically, the headrest stay main body 12 is composed of a pair of left and right vertical stays 14 that extend in the up-down direction and are aligned at a distance in the left-right direction, and a horizontal stay 16 that connects the upper ends of the left and right vertical stays 14 in the left-right direction.

[0023] The headrest stay main body 12 is bent into a curved shape at the boundary between the vertical stay 14 and the horizontal stay 16. Therefore, in the following description of this embodiment, a straight line A (shown as a dashed line in FIG. 1 ) connecting the center of the arc forming the curve and the intersection point between the center line of the vertical stay 14 and the center line of the horizontal stay 16 will be used as the boundary between the vertical stay 14 and the horizontal stay 16.

[0024] The headrest stay main body 12 has a flat portion 20 that is flat in the front-to-rear direction. The flat portion 20 is made up of the horizontal stay 16 and the upper end portions 14A of the pair of left and right vertical stays 14, and as an example, is formed to a thickness of about 10 mm with respect to a diameter of 14 mm of the pipe material that makes up the headrest stay main body 12.

[0025] Each of the pair of left and right vertical stays 14 has a cylindrical linear portion 14B extending downward from an upper end 14A having a flat shape in the front-to-rear direction. A connecting portion 14C, which is the upper end of the linear portion 14B connecting to the upper end 14A, is smoothly connected to the upper end 14A. Each of the pair of left and right vertical stays 14 also has a rear linear portion 14D extending rearward from the lower end of the linear portion 14B, and a lower linear portion 14E extending downward from the rear end of the rear linear portion 14D, with the boundary between each being curved. The lower end of the lower linear portion 14E is connected to the seat back 44. Specifically, the lower end of the lower linear portion 14E is supported by a pair of left and right headrest supports (not shown) provided at the upper end of the seat back 44 so that the height can be adjusted in the vertical direction.

[0026] As shown in Fig. 2, a headrest main body 32 is attached to the upper end of the headrest stay 10. The headrest main body 32 includes a trim cover 34, which is a covering material, and a pad material 36, which is a cushioning material, disposed inside the trim cover 34. The headrest main body 32 is placed over a headrest frame (not shown) that is fixed to the headrest stay 10. In this embodiment, the headrest 30 is configured to include the headrest stay 10, the headrest frame (not shown), and the headrest main body 32.

[0027] Here, in a state where the headrest stay 10 is assembled as the headrest 30, a plane S including the flat surface 20A of the flat portion 20 of the headrest stay main body 12 is shown by a dashed line in FIG.

[0028] 3, the headrest 30 configured as described above is disposed as part of a vehicle seat 40. The vehicle seat 40 includes a seat cushion 42 on which an occupant sits, a seat back 44 supported at the rear end of the seat cushion 42 so as to be able to recline, and the headrest 30 connected to the upper end of the seat back 44. The seat back 44 can be tilted in the front-rear direction of the vehicle seat 40 around a rotation axis (not shown) in the seat width direction by a reclining mechanism (not shown).

[0029] Next, the anthropomorphic dummy 50 used in vehicle rear-end collision tests will be described. FIG. 4 shows a schematic side view of the anthropomorphic dummy 50 used in rear-end collision tests. In this embodiment, BioRID-II is used as an example. This anthropomorphic dummy 50 was developed for rear-end collision tests and is 175 cm tall and weighs approximately 78 kg. In this embodiment, a detailed description of BioRID-II as the anthropomorphic dummy 50 will be omitted, and only the general configuration of the necessary parts will be described.

[0030] The anthropomorphic dummy 50 has a torso 52 and a head 54 attached to the upper end of a spinal column (not shown) provided on the torso 52. The anthropomorphic dummy 50 further has upper limbs (not shown) connected to the left and right upper parts of the torso 52, and lower limbs 56 connected to the left and right lower parts of the torso 52. The lower limbs 56 have thigh members 56A to which the waist 52A of the torso 52 is connected, lower leg members (not shown) connected to the thigh members 56A, and foot members (not shown) connected to the lower leg members (not shown).

[0031] Torso 52 and thigh member 56A are attached so as to be rotatable about hip point HP (see FIG. 5). That is, hip point HP serves as the axis of rotation for torso 52 and thigh member 56A. A straight line D passing through hip point HP of anthropomorphic dummy 50 and the center of gravity G of head 54 is shown by a dashed dotted line in FIG. 4.

[0032] Next, the positional relationship between the headrest stay 10 and the dummy 50 during a rear-end collision test conducted with the dummy 50 seated in the vehicle seat 40 will be described. The rear-end collision test is a test that reproduces a situation in which a vehicle is hit from behind while stopped, and measures the degree of impact received by the neck of the dummy 50. In this embodiment, the rear-end collision test is conducted using the vehicle seat 40, by reproducing an installation state similar to that of an actual vehicle on a test trolley, and driving collision material into the trolley to reproduce a rear-end collision. As shown in FIG. 5, the rear-end collision test is conducted with the dummy 50 seated in the seat cushion 42.

[0033] During a rear-end collision, the dummy 50 seated in the vehicle seat 40 rotates about the hip point HP and moves in the fore-and-aft direction of the vehicle seat 40. As shown in Fig. 5 , in this embodiment, as an example, the center of gravity G of the head 54 of the dummy 50 moves from a line D1 passing through the hip point HP on the front side of the vehicle seat 40 in the fore-and-aft direction (front of the vehicle) to a line D2 passing through the hip point HP on the rear side of the vehicle seat 40 in the fore-and-aft direction (rear of the vehicle). When the center of gravity G of the head 54 of the dummy 50 is located on the line D2, the head 54 of the dummy 50 comes into contact with the front surface of the headrest 30.

[0034] In addition, in the present embodiment, in a side view of the vehicle seat 40, the flat surface 20A of the flat portion 20 is formed substantially parallel to a straight line D2 that passes through the center of gravity G of the head 54 of the dummy 50 and the hip point HP of the dummy 50 when the head 54 of the dummy 50 contacts the headrest main body 32. In other words, in a side view of the vehicle seat 40, a plane S that includes the flat surface 20A of the flat portion 20 of the headrest stay main body 12 and the straight line D2 are formed substantially parallel to each other.

[0035] Fig. 6 shows an enlarged side view of the main part of Fig. 5. As shown in Fig. 6, in this embodiment, when the head 54 of the dummy 50 comes into contact with the headrest main body 32, a perpendicular line P from a straight line D2 passing through the center of gravity G of the head 54 passes through the flat surface 20A of the flat portion 20 in a side view of the vehicle seat 40. Note that the perpendicular line P may pass anywhere on the flat surface 20A, but it is preferable that it passes through the center.

[0036] (Action, effect) Next, the effects of the headrest 30 to which the headrest stay structure according to the first embodiment is applied will be described below.

[0037] In the headrest stay structure according to the first embodiment, the flat portion 20 provided on the headrest stay main body 12 has a flat surface 20A in the front-rear direction of the seat back 44. Therefore, the contact between the headrest stay main body 12 and the head 54 of the dummy 50 can be surface contact, which increases the contact surface with the head 54 of the dummy 50 compared to point contact or line contact, and allows the head 54 of the dummy 50 to abut against the flat portion 20 stably regardless of the behavior of the dummy 50.

[0038] Furthermore, in the headrest stay structure of the first embodiment, when the head 54 of the dummy 50 comes into contact with the headrest main body 32 during a rear-end collision test in which the dummy 50 is seated in the vehicle seat 40, the flat surface 20A of the flat portion 20 is formed so that, in a side view of the vehicle seat 40, the flat surface 20A is approximately parallel to a line D2 passing through the hip point HP of the dummy 50 and the center of gravity G of the head 54 of the dummy 50, and a perpendicular line P from the line D2 passing through the center of gravity G of the head 54 passes through the flat surface 20A.

[0039] As a result, during a rear-end collision test, when the head 54 of the dummy 50 comes into contact with the headrest main body 32, the flat surface 20A of the flat portion 20 faces the head 54 of the dummy 50, allowing the head 54 of the dummy 50 to stably abut against the flat surface 20A of the flat portion 20. As described above, by allowing the head 54 of the dummy 50 to stably abut against the flat portion 20, robustness can be improved without using additional parts made of, for example, EPP.

[0040] Furthermore, in the headrest stay structure according to the first embodiment, the flat portion 20 is composed of the horizontal stay 16 and the upper end portions 14A of the pair of left and right vertical stays 14. In this way, since the flat portion 20 is composed of both the horizontal stays 16 and the vertical stays 14, the head 54 of the dummy 50 can be stably abutted against the flat portion 20 even when the head 54 of the dummy 50 behaves in the left-right direction and the up-down direction.

[0041] In the first embodiment, the flat portion 20 is made up of the horizontal stay 16 and the upper end portions 14A of the pair of left and right vertical stays 14, but the present invention is not limited to this. The flat portion 20 may be made up of, for example, only the horizontal stay 16, or only a portion of the horizontal stay 16. In this case, the head of the anthropomorphic dummy can be stably abutted against the flat portion in response to left-right movement of the head of the anthropomorphic dummy.

[0042] Second Embodiment Hereinafter, a headrest stay 100 to which a headrest stay structure according to the second embodiment is applied will be described with reference to Figures 7 and 8. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof will be omitted, and only the differences will be described in detail.

[0043] As shown in Fig. 7, the flat portion 200 of the headrest stay 100 to which the headrest stay structure according to the second embodiment is applied differs from the flat portion 20 of the first embodiment in the range in which the flat surface 20A is provided. The flat portion 200 of the second embodiment is composed of a horizontal stay 16, an upper end portion 14A, and a straight portion 14B extending downward from the upper end portion 14A. A connecting portion 14F, which is the lower end of the straight portion 14B that connects to the rear straight portion 14D, is smoothly connected to the rear straight portion 14D.

[0044] The lower end of the lower straight portion 14E is connected to the seat back 44, and specifically, as an example, is supported by a pair of left and right headrest supports (not shown) provided at the upper end of the seat back 44 so that the height can be adjusted in the up and down direction. In the second embodiment, the headrest main body 32 attached to the headrest stay 100 is positioned at a height intermediate between the lower limit position and the upper limit position of the height adjustable range. Here, the height of the intermediate position means a position where the distance from the lower limit position is equal to the distance from the upper limit position.

[0045] 8, in the flat portion 200 of the second embodiment, as in the first embodiment, the flat surface 20A is formed substantially parallel to a straight line D2 passing through the center of gravity G of the head 54 of the dummy 50 and the hip point HP of the dummy 50 when the head 54 of the dummy 50 contacts the headrest main body 32. Furthermore, when the head 54 of the dummy 50 contacts the headrest main body 32, a perpendicular line P from the straight line D2 passing through the center of gravity G of the head 54 passes through the flat surface 20A of the flat portion 200 in a side view of the vehicle seat 40.

[0046] Furthermore, in the second embodiment, when the head 54 of the dummy 50 comes into contact with the headrest main body 32, the height HG of the center of gravity G of the head 54 is included in the height direction of the flat portion 200 of the headrest stay 100, i.e., the height between height H1 and height H2 in Fig. 8. In other words, the flat portion 200 is provided at a height position that includes the height HG of the center of gravity G of the head 54 when the head 54 of the dummy 50 comes into contact with the headrest main body 32.

[0047] (Action, effect)

[0048] Next, the effects of the headrest 30 to which the headrest stay structure according to the second embodiment is applied will be described below.

[0049] In the headrest stay structure according to the second embodiment, when the headrest main body 32 is positioned at a height intermediate between the lower limit position and the upper limit position of the height adjustable range, the flat portion 200 is provided at a height position that includes the height HG of the center of gravity G of the head 54 of the dummy 50 when the head 54 of the dummy 50 comes into contact with the headrest main body 32. As a result, during a rear-end collision test, when the head 54 of the dummy 50 comes into contact with the headrest main body 32, the height direction of the flat portion 200 includes the height HG of the center of gravity G of the head 54 of the dummy 50, and the head 54 of the dummy 50 can come into contact with the flat portion 200 more stably than in the first embodiment.

[0050] (Supplementary explanation of the embodiment) In the above embodiment, in the vehicle seat 40 employing the headrest 30 on which the headrest stay structure of the present invention is mounted, the seat back 44 is able to tilt in the front-rear direction of the vehicle seat 40 by a reclining mechanism (not shown). However, the headrest stay structure of the present invention is not limited to this, and can also be employed in a vehicle seat 40 that does not have a reclining function.

[0051] Furthermore, in the above-described embodiment, the headrest 30 on which the headrest stay structure of the present invention is mounted does not have a tilting function, but the headrest stay structure of the present invention can also be used in a headrest 30 that has a tilting function.

[0052] Furthermore, in the above embodiment, the headrest stay main body 12 is described as having a substantially inverted U shape when viewed in the front-rear direction, but the shape of the headrest stay main body 12 can also be changed as appropriate.

[0053] Furthermore, in the above embodiment, BioRID-II was used as the dummy 50, but the present invention is not limited to this, and various dummy models used in rear impact tests can be used.

[0054] Furthermore, in the second embodiment, the flat portion 200 of the headrest stay 100 is configured to have a different range of the flat surface 20A than the flat portion 20 of the first embodiment, but the present invention is not limited to this. In the first embodiment, the headrest main body 32 attached to the headrest stay 100 may be positioned at a height intermediate between the lower limit position and the upper limit position, and the height direction of the flat portion 20 of the first embodiment may be set at a height position including the height HG of the center of gravity G of the head 54 of the anthropomorphic dummy 50 when the head 54 and the headrest main body 32 come into contact with each other.

[0055] Although one embodiment of the present invention has been described above, the present invention is not limited to such an embodiment, and one embodiment may be appropriately combined with various modified examples, and the present invention may of course be embodied in various forms as long as it does not deviate from the gist of the present invention. [Explanation of symbols]

[0056] 12 Headrest stay body 14 Vertical stay 16 Horizontal stay 20 Flat part 200 Flat part 20A, S flat surface 30 Headrest 40 Vehicle seats 44 Seatback 50 anthropomorphic dummies 54 Head G center of gravity HP Hip Point HG Center of gravity height D2 straight line P perpendicular

Claims

1. a headrest stay body having one end connected to a seat back of a vehicle seat and the other end to which a headrest body is attached; a flat portion that is provided on the headrest stay main body, has a flat surface in the front-rear direction of the seat back, and is formed so that when the head of the dummy sits on the vehicle seat and the headrest main body come into contact with each other during a rear collision test, the flat surface is approximately parallel to a line that passes through the hip point of the dummy and the center of gravity of the head, and a perpendicular line from the line that passes through the center of gravity of the head passes through the flat surface in a side view of the vehicle seat; A headrest stay structure having:

2. 2. The headrest stay structure according to claim 1, wherein when the headrest body is positioned at a height intermediate between the lower limit position and the upper limit position of the height adjustable range, the flat portion is provided at a height position that includes the height of the center of gravity of the head at the time of contact.

3. The headrest stay body includes a pair of vertical stays, one end of which is connected to the seat back, and a horizontal stay that connects the pair of vertical stays, 3. The headrest stay structure according to claim 1, wherein the flat portion includes at least a part of the horizontal stay.

4. 4. The headrest stay structure according to claim 3, wherein the flat portion includes both the horizontal stay and the vertical stay.

5. A headrest stay structure as described in Claim 4, wherein the flat portion of the headrest stay main body is formed thinner than the portion other than the flat portion.

6. A headrest stay structure as described in Claim 4, wherein the headrest stay main body is integrally molded including the pair of vertical stays and the horizontal stays.

7. A headrest stay structure as described in Claim 4, wherein the headrest stay main body is integrally molded including the pair of vertical stays and the horizontal stays, and the flat portion is formed thinner than the portions other than the flat portion.

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