Energy absorber and seat belt device

Abstract

To provide an energy absorber which can reduce a load applied to an occupant by webbing during a vehicle collision with a simple structure, and to provide a seat belt device.SOLUTION: An energy absorber 1 according to an embodiment of the invention reduces a load caused by webbing which restrains an occupant when the occupant is restrained. The energy absorber 1 includes: a movable part 2 connected to a component which guides or restrains the webbing; a fixing part 3 connected to a vehicle body or a seat; at least one link mechanism 4 disposed between the movable part 2 and the fixing part 3; and a torsion bar 5 which is disposed in at least one rotation part 50 of the link mechanism 4 and enables torsional deformation.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an energy absorbing device and a seat belt apparatus, and more particularly to an energy absorbing device capable of reducing the load applied to an occupant by a webbing during a vehicle collision, and a seat belt apparatus equipped with the energy absorbing device. [Background technology]

[0002] In vehicles such as automobiles, a seat belt device for restraining an occupant is generally provided on a seat having a seat portion on which the occupant sits and a backrest portion located behind the occupant. Such a seat belt device generally includes a webbing for restraining the occupant, a retractor for winding up the webbing, a guide anchor provided on the vehicle body side for guiding the webbing, a belt anchor for fixing the webbing to the vehicle body side, a buckle provided on the side of the seat, and a tongue provided on the webbing, and the occupant is restrained by the webbing by fitting the tongue into the buckle.

[0003] When the seat belt is fastened, the webbing stretched between the guide anchor and the buckle constitutes the shoulder belt portion that restrains the upper body of the occupant, and the webbing stretched between the buckle and the belt anchor constitutes the lap belt portion that restrains the waist of the occupant. In the event of a vehicle collision, the occupant moves forward due to inertial force, so a large load is generated on the lap belt portion. Various methods have already been proposed for energy absorbing devices that reduce the load generated on the lap belt portion.

[0004] For example, Patent Document 1 discloses a buckle device comprising: a buckle body to which a tongue attached to a three-point seat belt is connected; a flexible connecting member having one longitudinal end connected to the buckle body; a winding shaft supported rotatably with respect to the vehicle seat or vehicle body on the vehicle underside of the buckle body and around which the other longitudinal end of the connecting member is wound; and a force limiter mechanism having a torsion shaft that is torsionally deformed by rotation of the winding shaft, the torsion shaft being coaxially arranged next to the winding shaft in the axial direction on the front side of the vehicle. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 7132141 Summary of the Invention [Problem to be solved by the invention]

[0006] In the invention described in Patent Document 1, the connecting member of the buckle body is wound around a winding shaft, and the winding shaft is configured as a torsion shaft that can be twisted, thereby reducing the load applied to the occupant by the lap belt portion during a vehicle collision. Therefore, the invention described in Patent Document 1 has problems such as a complicated structure and a large number of parts.

[0007] The present invention has been devised in view of the above problems, and has an object to provide an energy absorbing device and a seat belt device that have a simple structure and can reduce the load imposed on an occupant by the webbing during a vehicle collision. [Means for solving the problem]

[0008] According to the present invention, there is provided an energy absorbing device that reduces the load acting on an occupant due to a webbing that restrains the occupant when the occupant is restrained, the energy absorbing device comprising: a movable part connected to a part that guides or restrains the webbing, a fixed part connected to a vehicle body or a seat, at least one link mechanism arranged between the movable part and the fixed part, and a torsion bar that can be twisted and deformed that is arranged in at least one rotating part of the link mechanism.

[0009] The link mechanism may comprise a movable side link member including the movable portion, and a fixed side link member including the fixed portion, and the torsion bar may be arranged in a rotating portion formed between the movable side link member and the fixed side link member.

[0010] Furthermore, the torsion bar may be disposed in either or both of a rotating portion formed between the movable portion and the movable side link member and a rotating portion formed between the fixed portion and the fixed side link member.

[0011] In addition, the link mechanism may include a movable side link member including the movable portion, a fixed side link member including the fixed portion, and an intermediate link member arranged between the movable side link member and the fixed side link member, and the torsion bar may be arranged in either or both of a rotating portion formed between the movable side link member and the intermediate link member and a rotating portion formed between the fixed side link member and the intermediate link member.

[0012] In addition, the torsion bar may be arranged in either or both of a rotating portion formed between the movable portion and the movable side link member and a rotating portion formed between the fixed portion and the fixed side link member.

[0013] In addition, the torsion bar may have a first end having a polygonal shape that can fit into a polygonal engagement hole formed in one of the members that constitute the rotating part, and a second end having a plurality of protrusions that can engage with a plurality of recesses formed on the back surface of the other member that constitutes the rotating part.

[0014] The torsion bar may also include a protrusion that protrudes outward when the first end is engaged with the engagement hole, and the protrusion may have a groove in which a clasp can be positioned.

[0015] Moreover, the component that guides or restrains the webbing is, for example, a belt anchor, a guide anchor, or a buckle.

[0016] According to the present invention, there is also provided a seat belt device comprising an energy absorbing device having any one of the above-described configurations. Effect of the Invention

[0017] According to the energy absorbing device and seat belt device of the present invention described above, the energy absorbing mechanism is constituted by the link mechanism and the torsion bar arranged on the rotating part of the link mechanism, so that the parts that guide or restrain the webbing can be moved with a predetermined load. Therefore, according to the present invention, it is possible to reduce the load applied to the occupant by the webbing during a vehicle collision with a simple structure. [Brief description of the drawings]

[0018] [Figure 1] 1A and 1B are diagrams showing an energy absorbing device according to a first embodiment of the present invention, in which FIG. 1A is a perspective view and FIG. [Diagram 2] FIG. 2 is a component exploded view of the energy absorbing device shown in FIG. [Diagram 3] 2A and 2B are side views showing the operation of the energy absorbing device shown in FIG. 1, in which (A) shows the state before operation and (B) shows the state after operation. [Figure 4]1 is a perspective view showing a seat belt device according to an embodiment of the present invention; [Diagram 5] 5A and 5B are side views showing the operation of the energy absorbing device in the seatbelt device shown in FIG. 4, in which (A) shows the state before operation and (B) shows the state after operation. [Figure 6] FIG. 4 is a perspective view showing an energy absorbing device according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a plan view showing an energy absorbing device according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an embodiment of the present invention will be described with reference to Fig. 1(A) to Fig. 7. Fig. 1 shows an energy absorbing device according to a first embodiment of the present invention, where (A) is a perspective view and (B) is a front view. Fig. 2 is a component exploded view of the energy absorbing device shown in Fig. 1. Fig. 3 is a side view showing the operation of the energy absorbing device shown in Fig. 1, where (A) shows the state before operation and (B) shows the state after operation.

[0020] An energy absorbing device 1 according to a first embodiment of the present invention is an energy absorbing device that reduces the load acting on an occupant due to a webbing that restrains the occupant when the occupant is restrained, as shown in, for example, Figures 1(A) to 2, and includes a movable part 2 connected to a part that guides or restrains the webbing, a fixed part 3 connected to a vehicle body or a seat, at least one link mechanism 4 arranged between the movable part 2 and the fixed part 3, and a torsion bar 5 that is torsionally deformable and arranged in at least one rotating part 50 of the link mechanism 4.

[0021] The component that guides or restrains the webbing is, for example, the buckle 21. The buckle 21 is a component into which a tongue is fitted when an occupant fastens the seat belt. Note that the component that guides or restrains the webbing is not limited to the buckle 21, and may be a belt anchor, a guide anchor, or the like.

[0022] The movable part 2 means an end part whose position changes due to the driving of the link mechanism 4 which accompanies the rotation of the rotating part 50. The movable part 2 is connected to a part (e.g., a buckle 21) that guides or restrains an occupant in the event of a vehicle collision.

[0023] The fixed part 3 means the end part on the positioned side whose position does not move due to the driving of the link mechanism 4. The fixed part 3 is a base end part that does not move even during a vehicle collision, and is therefore arranged on the vehicle body structure side such as the vehicle body or the seat.

[0024] The link mechanism 4 includes, for example, a movable side link member 41 including the movable part 2, and a fixed side link member 42 including the fixed part 3. A first end 41a of the movable side link member 41 is rotatably connected to the buckle 21, and constitutes the movable part 2. A second end 41b of the movable side link member 41 is rotatably connected to a first end 42a of the fixed side link member 42, and constitutes the rotating part 50. A second end 42b of the fixed side link member 42 is rotatably connected to the seat or the vehicle body, and constitutes the fixed part 3.

[0025] The movable link member 41 has a shape in which, for example, a rectangular plate is combined with a disk-shaped plate on both ends, but is not limited to such a shape. As shown in Fig. 2, the movable link member 41 has an opening 41c formed at a first end 41a. A metal fitting 22 that is rotatably connected to the buckle 21 is connected to the opening 41c. The metal fitting 22 has, for example, a pin shape, and the head is engaged with the opening 41c, and a fastening member such as a nut is connected to the tip from the buckle 21 side.

[0026] 2, the second end portion 41b has an engagement hole 41d that engages with the torsion bar 5. The engagement hole 41d is, for example, a hole having a polygonal shape, such as a hexagonal shape, in the circumferential direction.

[0027] The fixed side link member 42 has a shape in which, for example, a rectangular plate material is combined with a disk-shaped plate material on both ends, but is not limited to such a shape. As shown in FIG. 2, an opening 42c is formed in the second end portion 42b. A fixing bolt 31 for fixing the fixed side link member 42 to the vehicle body or the seat is inserted into the opening 42c. At this time, the fixed side link member 42 is supported rotatably with respect to the fixing bolt 31.

[0028] 2, the first end 42a has an insertion hole 42d through which the torsion bar 5 is inserted, and an engagement portion 42e formed on the surface opposite to the side on which the movable link member 41 is disposed and which engages with the torsion bar 5. The engagement portion 42e is disposed along the periphery of the insertion hole 42d. The engagement portion 42e has, for example, a cylindrical shape with a plurality of recesses in the circumferential direction. That is, the fixed link member 42 has a plurality of recesses formed on the back surface of the other member (movable link member 41) that constitutes the rotating portion 50.

[0029] The torsion bar 5 is a generally cylindrical energy absorbing member disposed at the second end 41b of the movable link member 41 and the first end 42a of the fixed link member 42. The torsion bar 5 is configured to maintain its shape without deformation until a predetermined torsional load is generated, and to undergo torsional deformation when the predetermined torsional load is exceeded.

[0030] The torsion bar 5 has a length that allows the second end 41b of the movable link member 41 and the first end 42a of the fixed link member 42 to be fixed in an overlapping state. That is, the torsion bar 5 has an axial length that is approximately the thickness of the overlapping plates of the movable link member 41 and the fixed link member 42 (including the engaging portion 42e). Therefore, as shown in FIG. 1(B), the lateral width D required for installation of the energy absorbing device 1 can be made thinner than that of conventional energy absorbing devices.

[0031] As shown in FIG. 2, the torsion bar 5 has a first end 51 having a polygonal shape that can fit into a polygonal engagement hole 41d formed in one of the members (movable side link member 41) that constitute the rotating part 50, and a second end 52 having a plurality of protrusions 53 that can engage with a plurality of recesses (engagement portions 42e) formed on the back surface of the other member (fixed side link member 42) that constitutes the rotating part 50.

[0032] The first end 51 has a shape that matches the shape of the engagement hole 41d, for example, a hexagonal shape. The protrusion 53 fits into the recess of the engagement portion 42e when the torsion bar 5 is inserted into the insertion hole 42d of the fixed side link member 42. Note that the method of engaging the torsion bar 5 is not limited to the configuration shown in the figure.

[0033] The torsion bar 5 also has a protruding portion 54 that protrudes outward when the first end 51 is engaged with the engagement hole 41d. The protruding portion 54 constitutes a retaining portion for the torsion bar 5, and has a groove in which a clasp 55 can be placed. The clasp 55 is, for example, a C-ring. However, the configuration of the retaining portion is not limited to this configuration.

[0034] The link mechanism 4 of the first embodiment shown in the figures has a rotating part that is rotatably connected at three points: the movable part 2, the fixed part 3, and the intermediate part (between the movable side link member 41 and the fixed side link member 42). Here, we describe the case where a torsion bar 5 is arranged in the intermediate part of the link mechanism 4 (between the movable side link member 41 and the fixed side link member 42).

[0035] Although not shown, a torsion bar may be disposed in the rotating part of the movable part 2 or the fixed part 3. That is, the torsion bar 5 may be disposed in either or both of the rotating part formed between the movable part 2 and the movable-side link member 41 and the rotating part formed between the fixed part 3 and the fixed-side link member 42.

[0036] As shown in Fig. 3(A), when the energy absorbing device 1 is assembled, the movable side link member 41 and the fixed side link member 42 are arranged to form a substantial V-shape. Since the movable side link member 41 and the fixed side link member 42 are connected via the torsion bar 5, even if the buckle 21 is pulled diagonally upward by the webbing, if the torque generated in the torsion bar 5 is a load equal to or less than a predetermined threshold value, the link mechanism formed by the movable side link member 41 and the fixed side link member 42 does not move, and the state shown in Fig. 3(A) is maintained.

[0037] On the other hand, as shown in Figure 3 (B), when a large load is applied to the buckle 21 in the direction of the arrow in the figure and the torque generated in the torsion bar 5 exceeds a predetermined threshold value, the torsion bar 5 is twisted and deformed, causing the link mechanism 4 composed of the movable side link member 41 and the fixed side link member 42 to move and deform in a direction widening the angle between the movable side link member 41 and the fixed side link member 42.

[0038] As shown in the figure, the movable link member 41 and the fixed link member 42 deform to a substantially I-shape (the angle between the movable link member 41 and the fixed link member 42 is 180°) at maximum deformation. This deformation of the link mechanism 4 allows the position of the buckle 21 to be moved, thereby reducing the load applied to the occupant by the webbing.

[0039] The amount of energy absorption by the energy absorbing device 1 can be set, for example, by the threshold value of the torsional deformation of the torsion bar 5, the diameter and length of the torsion bar 5, the length of the movable link member 41, the length of the fixed link member 42, etc.

[0040] According to the energy absorption device 1 of this embodiment described above, the energy absorption mechanism is constituted by the link mechanism 4 and the torsion bar 5 arranged at the rotating part of the link mechanism 4, so that the parts that guide or restrain the webbing (e.g., the buckle 21) can be moved with a predetermined load, and the load acting on the occupant due to the webbing during a vehicle collision can be reduced with a simple structure.

[0041] Next, a seatbelt device according to one embodiment of the present invention will be described with reference to Fig. 4 to Fig. 5(B). Here, Fig. 4 is a perspective view showing a seatbelt device according to one embodiment of the present invention. Fig. 5 is a side view showing the operation of an energy absorbing device in the seatbelt device shown in Fig. 4, where (A) shows a state before operation and (B) shows a state after operation. Note that in Fig. 5(A) and Fig. 5(B), illustrations of the webbing are omitted for convenience of explanation.

[0042] The seat belt device 10 of this embodiment shown in Figure 4 includes a webbing W for restraining an occupant, a seat belt retractor 11 for winding up the webbing W, a guide anchor 12 provided on the vehicle body side for guiding the webbing W, a belt anchor 13 for fixing the webbing W to the vehicle body side, a buckle 21 arranged on the side of the seat S on which the occupant is seated, and a tongue 14 arranged on the webbing W.

[0043] The seat S includes, for example, a seat portion S1 on which an occupant sits, a backrest portion S2 located behind the occupant, and a headrest portion S3 for supporting the occupant's head. The seat belt retractor 11 is built into, for example, a B-pillar of the vehicle body.

[0044] In general, the buckle 21 is often disposed on a side surface of the seating portion S1, and the belt anchor 13 is often disposed on the side surface or underside of the seating portion S1. The guide anchor 12 is often disposed on the B-pillar P. One end of the webbing W is connected to the belt anchor 13, and the other end is connected to the seat belt retractor 11 via the guide anchor 12.

[0045] When an occupant (not shown) seated in the seat S engages the tongue 14 with the buckle 21, the occupant is restrained in the seat S by the webbing W. At this time, the webbing stretched between the belt anchor 13 and the buckle 21 constitutes a lap belt portion W1 that restrains the occupant's waist. In addition, the webbing stretched between the buckle 21 and the guide anchor 12 constitutes a shoulder belt portion W2 that restrains the upper body (particularly the shoulders) of the occupant.

[0046] In the seat belt device 10 according to this embodiment, the above-mentioned energy absorbing device 1 is disposed in the buckle 21. Therefore, in a normal use state, as shown in Fig. 5(A), the energy absorbing device 1 does not operate and the position of the buckle 21 is maintained.

[0047] When an event such as a vehicle collision occurs while the occupant is fastened with the seat belt, the occupant will tend to move forward due to inertial force, while the occupant's waist is restrained by the lap belt portion W1.

[0048] In this embodiment, since the above-mentioned energy absorbing device 1 is disposed in the buckle 21, when the torque generated in the torsion bar 5 generates a large load exceeding a predetermined threshold, the energy absorbing device 1 operates to move the buckle 21 obliquely upward as shown in Fig. 5(B). This movement of the buckle 21 can reduce the large load generated on the lumbar region of the occupant.

[0049] Next, an energy absorbing device according to another embodiment of the present invention will be described with reference to Figs. 6 to 7. Fig. 6 is a perspective view showing an energy absorbing device according to a second embodiment of the present invention. Fig. 7 is a plan view showing an energy absorbing device according to a third embodiment of the present invention. Note that the same components as those in the first embodiment described above are denoted by the same reference numerals and will not be described again.

[0050] 6 is an energy absorbing device 1 according to the second embodiment, which is obtained by modifying the configuration of the link mechanism 4 in the energy absorbing device 1 according to the first embodiment. Specifically, the link mechanism 4 includes a movable side link member 41 including the movable portion 2, a fixed side link member 42 including the fixed portion 3, and an intermediate link member 43 disposed between the movable side link member 41 and the fixed side link member 42.

[0051] Further, the torsion bar 5 is disposed at both a rotating portion 50a formed between the movable link member 41 and the intermediate link member 43 and a rotating portion 50b formed between the fixed link member 42 and the intermediate link member 43. In this manner, the link mechanism 4 may be composed of multiple link members, and the torsion bar 5 may be disposed at the rotatable connecting portions of the link members.

[0052] The torsion bar 5 may be disposed on only one of the rotating parts 50a and 50b. The threshold load at which the torsion bar 5 disposed on the rotating part 50a and the torsion bar 5 disposed on the rotating part 50b start to twist may be the same or different.

[0053] Also, although not shown, the torsion bar 5 may be arranged in either or both of the rotating part formed between the movable part 2 and the movable side link member 41 and the rotating part formed between the fixed part 3 and the fixed side link member 42.

[0054] As in the first and second embodiments described above, by employing the link mechanism 4 having the torsion bar 5 in the energy absorbing device 1, the amount of energy absorbed by the energy absorbing device 1 and the timing of energy absorption can be flexibly designed depending on conditions such as the location where the energy absorbing device 1 is disposed, the magnitude of the collision event, and the posture of the occupant.

[0055] The energy absorbing device 1 according to the third embodiment shown in FIG. 7 is applied to a guide anchor 12 (see FIG. 4). The guide anchor 12 is a component that is disposed on the B-pillar near the occupant's shoulder and guides the webbing from the occupant's shoulder to the waist. In the third embodiment, the movable part 2 is connected to the guide anchor 12, and the fixed part 3 is connected to the B-pillar. The link mechanism 4 has the same configuration as in the first embodiment. Moreover, the link mechanism 4 may be configured by multiple link members as in the second embodiment shown in FIG. 6.

[0056] Although not shown, the energy absorbing device 1 may be disposed in the belt anchor 13 (see FIG. 4). In this case, the movable part 2 is connected to a metal fitting of the belt anchor 13, and the fixed part 3 is connected to the vehicle body or the seat. The link mechanism 4 has the same configuration as in the first to third embodiments.

[0057] As described above, the energy absorbing device 1 is disposed in one or more of the components of the belt anchor 13, the guide anchor 12, and the buckle 21. For example, when it is desired to absorb the energy of only the lap belt portion W1 (see FIG. 4), the energy absorbing device 1 may be disposed in the belt anchor 13. On the other hand, when it is desired to absorb the energy of only the shoulder belt portion W2 (see FIG. 4), the energy absorbing device 1 may be disposed in the guide anchor 12.

[0058] When it is desired to absorb energy from both the lap belt portion W1 and the shoulder belt portion W2 (see FIG. 4), the energy absorbing device 1 may be arranged only in the buckle 21, or in the belt anchor 13 and the guide anchor 12, or in all of the buckle 21, the belt anchor 13 and the guide anchor 12.

[0059] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0060] 1 Energy absorbing device 2 Moving parts 3 Fixed part 4 Link mechanism 5 Torsion bar 10 Seat belt device 11 Seat belt retractor 12 Guide anchor 13 Belt anchor 14 Tongue 21 Buckle 22 Metal fittings 31 Fixing bolt 41 Movable link member 41a First end 41b Second end 41c opening 41d Engagement hole 42 Fixed side link member 42a First end 42b Second end 42c opening 42d Through hole 42e Engagement part 43 Intermediate link member 50, 50a, 50b Rotating part 51 First end 52 Second end 53 Protrusion 54 Protrusion 55 Clasp

Claims

1. An energy absorbing device that reduces a load applied to an occupant by a webbing that restrains the occupant when the occupant is restrained, A movable part connected to a part that guides or restrains the webbing; A fixing part connected to a vehicle body or a seat; At least one link mechanism disposed between the movable part and the fixed part; a torsion bar disposed in at least one rotating portion of the link mechanism and capable of torsional deformation; An energy absorbing device comprising:

2. 2. The energy absorbing device according to claim 1, wherein the link mechanism comprises a movable side link member including the movable portion and a fixed side link member including the fixed portion, and the torsion bar is disposed in a rotating portion formed between the movable side link member and the fixed side link member.

3. 3. The energy absorbing device according to claim 2, wherein the torsion bar is arranged in one or both of a rotating portion formed between the movable portion and the movable side link member and a rotating portion formed between the fixed portion and the fixed side link member.

4. 2. The energy absorbing device of claim 1, wherein the link mechanism comprises a movable side link member including the movable portion, a fixed side link member including the fixed portion, and an intermediate link member arranged between the movable side link member and the fixed side link member, and the torsion bar is arranged in either or both of a rotating portion formed between the movable side link member and the intermediate link member and a rotating portion formed between the fixed side link member and the intermediate link member.

5. 5. The energy absorbing device according to claim 4, wherein the torsion bar is arranged at either or both of a rotating portion formed between the movable portion and the movable side link member and a rotating portion formed between the fixed portion and the fixed side link member.

6. 2. The energy absorbing device as described in claim 1, wherein the torsion bar has a first end having a polygonal shape that can fit into a polygonal engagement hole formed in one of the members constituting the rotating part, and a second end having a plurality of protrusions that can engage with a plurality of recesses formed on a back surface of the other member constituting the rotating part.

7. The energy absorbing device according to claim 6 , wherein the torsion bar has a protrusion that protrudes outward when the first end is engaged with the engagement hole, and the protrusion has a groove in which a fastener can be positioned.

8. 2. The energy absorbing device of claim 1, wherein the component that guides or restrains the webbing is a belt anchor, a guide anchor, or a buckle.

9. A seat belt device comprising the energy absorbing device according to any one of claims 1 to 8.

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