Energy absorption device and seat belt device

Abstract

Provided is an energy absorption device and a seat belt device that can reduce shaft chatter and thereby reduce the occurrence of odd sounds. An energy absorption device 1 is provided with: a belt 2 connected to a component that guides or restrains webbing; a shaft part 3 around which the belt 2 is wrapped; a first torsional deformation section 4 disposed at a first end 31 of the shaft part 3; a second torsional deformation section 5 disposed at a second end 32 of the shaft part 3; a first connection section 6 disposed on the end of the first torsional deformation section 4 opposite the shaft part 3; a second connection section 7 disposed at the end of the second torsional deformation section 5 opposite the shaft-part 3; and a base 8 anchored to the vehicle-body side and including a first anchoring section 81 to which the first connection section 6 is connected, a second anchoring section 82 to which the second connection section 7 is connected, a first bearing section 83 that supports the first end 31 of the shaft part 3, and a second bearing section 84 that supports the second end 32 of the shaft part 3.

Description

Energy absorption device and seat belt device

[0001] The present invention relates to an energy absorbing device and a seat belt apparatus, and more particularly to an energy absorbing device and a seat belt apparatus that can reduce the load on an occupant when fastening a seat belt.

[0002] Vehicles such as automobiles are generally provided with a seat belt device for restraining an occupant in 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 for guiding the webbing, a belt anchor for fixing the webbing to the vehicle body, 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 a seat belt is fastened, the webbing stretched between the guide anchor and the buckle forms the shoulder belt portion that restrains the occupant's upper body, and the webbing stretched between the buckle and the belt anchor forms the lap belt portion that restrains the occupant's waist. During a vehicle collision, the occupant moves forward due to inertial force, generating large loads on the shoulder belt and lap belt portions. Various energy absorption devices have already been proposed to reduce these loads.

[0004] For example, Patent Document 1 describes a buckle device including a buckle body to which a tongue attached to a three-point seat belt is connected, webbing having one longitudinal end connected to the buckle body, and a force limiter mechanism (energy absorbing device). The force limiter mechanism includes a spool that is rotatably supported with respect to the vehicle seat on the vehicle lower side of the buckle body and around which the other longitudinal end of the webbing is wound, and a torsion shaft (energy absorbing member) that is deformed by rotation of the spool.

[0005] JP 2020-125010 A

[0006] The force limiter mechanism (energy absorption device) described in Patent Document 1 has a configuration in which a torsion shaft is disposed on one side of a spool, and has a configuration similar to the energy absorption mechanism using a torsion bar that is widely used in retractors. However, because this energy absorption device has a cantilever support structure, it has problems such as shaft wobble and the tendency to generate abnormal noise.

[0007] The present invention has been made in view of the above problems, and has an object to provide an energy absorbing device and a seat belt device that can reduce axial wobble and reduce the generation of abnormal noise.

[0008] According to the present invention, there is provided an energy absorption device that reduces a load acting on a webbing that restrains an occupant when the occupant is restrained, the energy absorption device comprising: a belt connected to a component that guides or restrains the webbing; a shaft portion around which the belt is looped; a first torsional deformation portion that is disposed at a first end of the shaft portion and is torsionally deformable under a predetermined load; a second torsional deformation portion that is disposed at a second end of the shaft portion and is torsionally deformable under a predetermined load; a first connecting portion that is disposed at an end of the first torsional deformation portion opposite to the shaft portion; a second connecting portion that is disposed at an end of the second torsional deformation portion opposite to the shaft portion; a first fixed portion to which the first connecting portion is connected; a second fixed portion to which the second connecting portion is connected; a first bearing portion that supports the first end of the shaft portion; and a second bearing portion that supports the second end of the shaft portion, and a base that is fixed to a vehicle body.

[0009] The first connecting portion may have an outer shape smaller than that of the shaft portion, and the second connecting portion may have an outer shape larger than that of the shaft portion.

[0010] The first fixing portion may have a first opening into which the first connecting portion is fitted, the second fixing portion may have a second opening into which the second connecting portion is fitted, the first bearing portion may have a third opening through which the shaft can be inserted, the second bearing portion may have a fourth opening through which the shaft can be inserted, the third opening and the fourth opening may be the same size, the first opening may be smaller than the third opening and the fourth opening, and the second opening may be larger than the third opening and the fourth opening.

[0011] The first torsional deformation portion and the second torsional deformation portion may be formed thinner than the shaft portion.

[0012] The shaft portion, the first torsional deformation portion, the second torsional deformation portion, the first connecting portion, and the second connecting portion may be integrally formed as a single shaft member.

[0013] The first torsional deformation portion, the second torsional deformation portion, the first connecting portion and the second connecting portion may be integrally formed as a single axial member, and the shaft portion may have a cylindrical shape that is fixed to the outer periphery of the axial member.

[0014] The shaft portion may have a slit portion through which the belt can be inserted.

[0015] The energy absorbing device may include a belt pin that forms a slit on the outer periphery of the shaft portion, through which the belt can be inserted.

[0016] Furthermore, according to the present invention, there is provided an energy absorption device that reduces a load acting on a webbing that restrains an occupant when the occupant is restrained, the energy absorption device including: a wire rope connected to a component that guides or restrains the webbing; a first torsional deformation portion that is arranged on a first end side and is torsionally deformable under a predetermined load; a second torsional deformation portion that is arranged on a second end side and is torsionally deformable under a predetermined load; a connecting portion that is arranged between the first torsional deformation portion and the second torsional deformation portion; a first connecting portion that is arranged on an end of the first torsional deformation portion opposite to the connecting portion; and a second connecting portion that is arranged on an end of the second torsional deformation portion opposite to the connecting portion; a cylindrical shaft portion fixed to the connecting portion and arranged on an outer periphery of the shaft member; a first fixed portion to which the first connecting portion is connected; a second fixed portion to which the second connecting portion is connected; and a pair of bearing portions that support both ends of the shaft portion, wherein the wire rope is wound around and fixed to the outer periphery of the shaft portion.

[0017] Furthermore, according to the present invention, there is provided an energy absorption device that reduces a load acting on a webbing that restrains an occupant when the occupant is restrained, the energy absorption device including: a wire rope connected to a component that guides or restrains the webbing; a shaft member that includes: a first torsional deformation portion that is arranged on a first end side and is torsionally deformable under a predetermined load; a second torsional deformation portion that is arranged on a second end side and is torsionally deformable under a predetermined load; a connecting portion that is arranged between the first torsional deformation portion and the second torsional deformation portion; a first connecting portion that is arranged on an end of the first torsional deformation portion opposite to the connecting portion; and a second connecting portion that is arranged on an end of the second torsional deformation portion opposite to the connecting portion; a cylindrical shaft portion that is fixed to the connecting portion and arranged on an outer periphery of the shaft member; a spool that is arranged on the outer periphery of the shaft portion; a first fixed portion to which the first connecting portion is connected; a second fixed portion to which the second connecting portion is connected; and a pair of bearing portions that support both ends of the shaft portion, wherein the wire rope is wound around and fixed to the outer periphery of the spool.

[0018] The first end of the wire rope may be fixed to the first end of the spool, the second end of the wire rope may be fixed to the second end of the spool, the wire rope may be wound from the first end and the second end of the spool toward the center, and the folded portion of the wire rope may be connected to a part that guides or restrains the webbing.

[0019] The spool may have a guide groove formed on its surface for winding the wire rope therethrough.

[0020] Furthermore, according to the present invention, there is provided an energy absorption device that reduces a load acting on a webbing that restrains an occupant when the occupant is restrained, the energy absorption device including: a connecting member connected to a component that guides or restrains the webbing; a first torsional deformation portion that is arranged on a first end side and is torsionally deformable under a predetermined load; a second torsional deformation portion that is arranged on a second end side and is torsionally deformable under a predetermined load; a connecting portion that is arranged between the first torsional deformation portion and the second torsional deformation portion; a first connecting portion that is arranged on an end of the first torsional deformation portion opposite to the connecting portion; and a second connecting portion that is arranged on an end of the second torsional deformation portion opposite to the connecting portion; a cylindrical shaft portion fixed to the connecting portion and arranged on an outer periphery of the shaft member; a first fixed portion to which the first connecting portion is connected; a second fixed portion to which the second connecting portion is connected; and a pair of bearing portions that support both ends of the shaft portion, wherein the connecting member is wrapped around and fixed to the outer periphery of the shaft portion.

[0021] The energy absorbing device may be part of a belt anchor, a guide anchor or a buckle.

[0022] According to the present invention, there is also provided a seat belt device comprising an energy absorbing device having any of the above-described configurations.

[0023] According to the energy absorption device and seat belt device of the present invention described above, by adopting a double-end support structure in which torsional deformation portions are arranged on both sides of the shaft portion around which the belt can be wound, it is possible to reduce axial wobble and the generation of abnormal noise.

[0024] FIG. 1 is a component exploded view showing an energy absorption device according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the energy absorption device shown in FIG. 1. FIG. 3 is a perspective view showing the operation of the energy absorption device, where (A) shows a state before operation and (B) shows a state after operation. FIG. 4 is a cross-sectional view showing the operation of the energy absorption device, where (A) shows a state before operation and (B) shows a state after operation. FIG. 5 is a view showing a first modified example of the energy absorption device, where (A) is a component exploded view and (B) is a front view. FIG. 6 is a view showing a second modified example of the energy absorption device, where (A) is a component exploded view and (B) is a perspective view. FIG. 7 is a front view showing an energy absorption device according to another embodiment of the present invention, where (A) is a second embodiment and (B) is a third embodiment. FIG. 8 is a perspective view showing a seatbelt device according to an embodiment of the present invention. FIG. 9 is an explanatory view showing the energy absorption device shown in FIG. 9, where (A) is a front view and (B) is a cross-sectional view of a shaft portion. FIG. 10 is a component exploded view showing an energy absorption device according to a fifth embodiment of the present invention. 12A and 12B are explanatory views showing the energy absorbing device shown in FIG. 11, in which FIG. 12A is a front view and FIG. 12B is a cross-sectional view of the shaft portion.

[0025] Hereinafter, embodiments of the present invention will be described with reference to Figs. 1 to 12(B). Fig. 1 is an exploded view showing an energy absorbing device according to a first embodiment of the present invention. Fig. 2 is a cross-sectional view of the energy absorbing device shown in Fig. 1. Fig. 3 is a perspective view showing the operation of the energy absorbing device, where (A) shows the state before operation and (B) shows the state after operation. Fig. 4 is a cross-sectional view showing the operation of the energy absorbing device, where (A) shows the state before operation and (B) shows the state after operation.

[0026] 1 and 2 , an energy absorption device 1 according to a first embodiment of the present invention is an energy absorption device that reduces a load acting on a webbing that restrains an occupant when the occupant is restrained, and includes: a belt 2 connected to a component that guides or restrains the webbing; a shaft portion 3 around which the belt 2 is looped; a first torsional deformation portion 4 that is disposed at a first end 31 of the shaft portion 3 and is torsionally deformable under a predetermined load; a second torsional deformation portion 5 that is disposed at a second end 32 of the shaft portion 3 and is torsionally deformable under a predetermined load; a first connecting portion 6 that is disposed at an end of the first torsional deformation portion 4 opposite to the shaft portion 3; a second connecting portion 7 that is disposed at an end of the second torsional deformation portion 5 opposite to the shaft portion 3; a first fixed portion 81 to which the first connecting portion 6 is connected; a second fixed portion 82 to which the second connecting portion 7 is connected; a first bearing portion 83 that supports the first end 31 of the shaft portion 3; and a second bearing portion 84 that supports the second end 32 of the shaft portion 3; and a base 8 that is fixed to the vehicle body.

[0027] The energy absorbing device 1 is applied to, for example, a part of a belt anchor that secures a webbing to a vehicle body. The belt 2 is, for example, a band-shaped body made of the same material as the webbing that restrains an occupant. A connecting metal fitting (not shown) that connects the belt 2 to the webbing is disposed on the end of the belt 2 opposite to the end connected to the shaft portion 3.

[0028] The shaft portion 3 is a metal or resin winding body connected to an end of the belt 2. For example, as shown in the figure, the shaft portion 3 may be integrally formed as a single shaft member 30 together with the first torsional deformation portion 4, the second torsional deformation portion 5, the first connecting portion 6, and the second connecting portion 7. A slit 33, which is an opening through which the belt 2 can be inserted, is formed in the middle portion of the shaft portion 3 (see FIG. 4 ).

[0029] After being inserted into the slit 33, the belt 2 is folded over and sewn at the seam 21. The folded over portion formed by the seam 21 of the belt 2 is wound around the shaft portion 3 several times. The number of turns of the belt 2 is set according to the stroke amount required to operate the energy absorbing device 1.

[0030] The first torsional deformation portion 4 has a cylindrical shape that can be torsionally deformed under a predetermined load. The first torsional deformation portion 4 is formed, for example, thinner than the shaft portion 3 and the first connecting portion 6. The length and thickness of the first torsional deformation portion 4 can be set arbitrarily depending on conditions such as the required torsional load and material.

[0031] The second torsional deformation portion 5 has a cylindrical shape that can be torsionally deformed under a predetermined load. The second torsional deformation portion 5 is formed, for example, thinner than the shaft portion 3 and the second connecting portion 7. The second torsional deformation portion 5 is made of the same material as the first torsional deformation portion 4 and has the same length and thickness as the first torsional deformation portion 4. The length and thickness of the second torsional deformation portion 5 can be set arbitrarily depending on conditions such as the required torsional load and material.

[0032] The first connecting portion 6 has a polygonal prism shape that is connected to the first fixing portion 81 of the base 8. The outer shape of the first connecting portion 6 is, for example, hexagonal, but is not limited to this configuration. A groove 61 for fixing a retaining washer 9 may be formed at the end of the first connecting portion 6 opposite the first torsional deformation portion 4. The outer shape (maximum diameter) of the first connecting portion 6 is formed smaller than the outer shape (diameter) of the shaft portion 3.

[0033] The second connecting portion 7 has a polygonal prism shape that is connected to the second fixing portion 82 of the base 8. The outer shape of the second connecting portion 7 is, for example, octagonal, but is not limited to this configuration. The outer shape (maximum diameter) of the second connecting portion 7 is formed to be larger than the outer shape (diameter) of the shaft portion 3. A stopper 71 that serves to prevent disengagement may be formed at the end of the second connecting portion 7 opposite the second torsional deformation portion 5. The outer shape (maximum diameter) of the stopper 71 is formed to be larger than the outer shape (diameter) of the second connecting portion 7.

[0034] By forming the thicknesses of the first connecting portion 6, the shaft portion 3, and the second connecting portion 7 so that they have the relationship of first connecting portion 6 < shaft portion 3 < second connecting portion 7, they can be inserted from one side when fixed to the base 8. Note that the thicknesses of the first torsional deformation portion 4 and the second torsional deformation portion 5 are formed to be smaller than that of the first connecting portion 6, for example, but may be larger than that of the first connecting portion 6 as long as they are smaller than the shaft portion 3.

[0035] The base 8 is a component equivalent to a bracket for fixing the shaft member 30 including the shaft portion 3 to a structural component on the vehicle body side. The base 8 has, for example, a substantially L-shaped cross section including a side portion 85 and a top plate portion 86. The side portion 85 is formed with a fastening hole 87 through which a fixing member for fixing the base 8 to the vehicle body side is inserted. The base 8 may be rotatably fixed to the structural component on the vehicle body side. The top plate portion 86 is formed with an insertion hole 88 through which the belt 2 is inserted. The first fixing portion 81, the second fixing portion 82, the first bearing portion 83, and the second bearing portion 84 are formed, for example, by plate-shaped portions formed on the side portion 85. Note that the external shape of the base 8 is not limited to the configuration shown in the figures.

[0036] The first fixing portion 81 has a first opening 81a into which the first connecting portion 6 is fitted. The first opening 81a has the same outer shape as the outer shape of the first connecting portion 6. In the present embodiment, the first opening 81a is a hexagonal opening.

[0037] The second fixing portion 82 has a second opening 82a into which the second connecting portion 7 is fitted. The second opening 82a has the same outer shape as the outer shape of the second connecting portion 7. In the present embodiment, the second opening 82a is an octagonal opening.

[0038] The first bearing portion 83 has a third opening 83a through which the shaft portion 3 can be inserted. The second bearing portion 84 has a fourth opening 84a through which the shaft portion 3 can be inserted. The first bearing portion 83 and the second bearing portion 84 are portions that constitute a bearing when the shaft portion 3 rotates, and are formed to be the same size.

[0039] The first opening 81a is smaller than the third opening 83a and the fourth opening 84a. The second opening 82a is larger than the third opening 83a and the fourth opening 84a. In this way, by forming the openings 81a and 82a so as to satisfy the relationship of first opening 81a < third opening 83a = fourth opening 84a < second opening 82a, simply by inserting the shaft member 30 from the second opening 82a side, the first connecting portion 6 can be fitted into the first fixed portion 81, the first end 31 of the shaft portion 3 can be inserted into the first bearing portion 83, the second end 32 of the shaft portion 3 can be inserted into the second bearing portion 84, and the second connecting portion 7 can be fitted into the second fixed portion 82.

[0040] Here, the operation of the energy absorbing device 1 will be described with reference to Figures 3(A) to 4(B). Before the energy absorbing device 1 is activated, as shown in Figures 3(A) and 4(A), the belt 2 is wound around the shaft portion 3. When the webbing is pulled by the inertial force of the occupant during a vehicle collision, a load is applied in the direction of pulling out the belt 2.

[0041] When the load in the direction of unwinding the belt 2 exceeds a predetermined threshold, the first torsional deformation portion 4 and the second torsional deformation portion 5 are torsionally deformed, the shaft portion 3 rotates, and the belt 2 is unwound as shown in Figures 3(B) and 4(B) . This unwinding amount (stroke) of the belt 2 can absorb the energy applied to the occupant by the webbing during a vehicle collision.

[0042] According to the energy absorbing device 1 of the first embodiment described above, a double-end support structure is adopted in which torsional deformation portions (first torsional deformation portion 4 and second torsional deformation portion 5) are arranged on both sides of the shaft portion 3 around which the belt 2 can be wound to support both ends of the shaft member 30, thereby reducing axial wobble of the shaft member 30 and reducing the generation of abnormal noise. Furthermore, according to the energy absorbing device 1 of the first embodiment, the structure can be simplified and the number of parts can be reduced compared to a cantilever support structure.

[0043] Next, modified examples of the energy absorbing device 1 will be described with reference to Figures 5(A) to 6(B). Figure 5 shows a first modified example of the energy absorbing device, where (A) is an exploded view and (B) is a front view. Figure 6 shows a second modified example of the energy absorbing device, where (A) is an exploded view and (B) is a perspective view. For ease of explanation, the belt 2 is omitted from each of Figures 5 and the base 8 is omitted from each of Figures 6.

[0044] 5(A) and 5(B), the shaft portion 3 constituting the shaft member is configured as a separate part. Specifically, the first torsional deformation portion 4, the second torsional deformation portion 5, the first connecting portion 6, and the second connecting portion 7 are integrally formed as a single shaft member 30a, and the shaft portion 3 has a cylindrical shape and is fixed to the outer periphery of the shaft member 30a.

[0045] The shaft member 30a includes a first expanded diameter portion 34 formed adjacent to the first torsional deformation portion 4, a second expanded diameter portion 35 formed adjacent to the second torsional deformation portion 5, and a connecting portion 36 connecting the first expanded diameter portion 34 and the second expanded diameter portion 35. For example, the first expanded diameter portion 34 and the second expanded diameter portion 35 have polygonal outer peripheries. The inner peripheries of both ends of the cylindrical member constituting the shaft portion 3 are formed into a shape that can fit into the first expanded diameter portion 34 and the second expanded diameter portion 35.

[0046] In this way, by making the shaft portion 3 a separate part, even if the difference in thickness between the first torsional deformation portion 4 and the second torsional deformation portion 5 and the shaft portion 3 becomes large, the shaft member 30a can be formed simply by increasing the cylindrical shape of the shaft portion 3, which is a separate part, thereby reducing the manufacturing cost of the shaft member.

[0047] 6(A) and 6(B) has a belt pin 37 that forms a slit on the outer periphery of the shaft portion 3, through which the belt 2 can be inserted. The shaft member 30 shown in the second modification is formed by integrally molding the shaft portion 3, as in the first embodiment described above, but the slit 33 of the first embodiment is omitted, and an opening through which the belt 2 can be inserted is formed by arranging the belt pin 37. With this configuration, there is no need to form a slit that penetrates the shaft portion 3, and the slit can be formed later.

[0048] The belt pin 37 has claws 37a at both ends that can be fixed to the shaft portion 3, and the shaft portion 3 has recesses 38 into which the claws 37a can be fixed. Note that the belt pin 37 is not limited to the configuration shown in the figure, as long as it has a structure that allows for the formation of a slit between the belt pin 37 and the shaft portion 3 that allows the belt 2 to be inserted therethrough. The second modified example can also be applied to the first modified example described above.

[0049] Next, other embodiments of the above-mentioned energy absorbing device 1 will be described with reference to Fig. 7(A) and Fig. 7(B). Here, Fig. 7 is a front view showing an energy absorbing device according to another embodiment of the present invention, (A) being a second embodiment, and (B) being a third embodiment.

[0050] 7(A) shows a second embodiment in which the energy absorption device 1 is applied to a part of a guide anchor 102. The base 8 is fixed to a pillar of the vehicle, and the belt 2 is connected to a belt guide 102b having an insertion hole 102a through which the webbing is slidably inserted.

[0051] 7(B) shows a third embodiment in which the energy absorbing device 1 is applied to a part of a buckle 104. The base 8 is fixed to the vehicle body (seat or vehicle body structure), and the belt 2 is connected to a buckle body 104a.

[0052] Next, a seat belt device according to one embodiment of the present invention will be described with reference to Fig. 8. Fig. 8 is a perspective view showing the seat belt device according to one embodiment of the present invention.

[0053] The seat belt device 100 according to this embodiment shown in Figure 8 includes a webbing W for restraining an occupant, a seat belt retractor 101 for winding up the webbing W, a guide anchor 102 provided on the vehicle body side for guiding the webbing W, a belt anchor 103 for fixing the webbing W to the vehicle body side, a buckle 104 provided on the side of the seat S on which the occupant sits, and a tongue 105 provided on the webbing W.

[0054] 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 that supports the occupant's head. The seat belt retractor 101 is built into, for example, a B-pillar of the vehicle body.

[0055] In general, the buckle 104 is often located on the side surface of the seat S1, and the belt anchor 103 is often located on the side surface or underside of the seat S1. The guide anchor 102 is often located on the B-pillar. One end of the webbing W is connected to the belt anchor 103, and the other end is connected to the seat belt retractor 101 via the guide anchor 102.

[0056] When an occupant (not shown) seated in the seat S engages the tongue 105 with the buckle 104, the occupant is restrained in the seat S by the webbing W. At this time, the webbing stretched between the belt anchor 103 and the buckle 104 constitutes a lap belt portion W1 that restrains the occupant's waist. In addition, the webbing stretched between the buckle 104 and the guide anchor 102 constitutes a shoulder belt portion W2 that restrains the occupant's upper body (particularly the shoulders).

[0057] The energy absorbing device 1 is disposed in one or more of the components of the belt anchor 103, the guide anchor 102, and the buckle 104. For example, when it is desired to absorb the energy of only the lap belt portion W1, the energy absorbing device 1 may be disposed in the belt anchor 103. When it is desired to absorb the energy of only the shoulder belt portion W2, the energy absorbing device 1 may be disposed in the guide anchor 102.

[0058] If it is desired to absorb the energy of both the lap belt portion W1 and the shoulder belt portion W2, the energy absorption device 1 may be placed only on the buckle 104, or on the belt anchor 103 and the guide anchor 102, or on all of the buckle 104, belt anchor 103 and guide anchor 102.

[0059] 8 illustrates a case where the energy absorbing device 1 is employed in the belt anchor 103. When the energy absorbing device 1 is employed in the belt anchor 103, the belt 2 may be formed of a webbing by wrapping an end of the webbing around the shaft portion 3.

[0060] According to the seat belt device 100 of the above-described embodiment, it is possible to reduce axial wobble of the shaft member 30 and reduce the generation of abnormal noise by employing a double-end support structure in the energy absorbing device 1. Furthermore, according to the seat belt device 100 of the present embodiment, it is possible to simplify the structure and reduce the number of parts compared to an energy absorbing device having a cantilever support structure.

[0061] Next, an energy absorbing device according to a fourth embodiment of the present invention will be described with reference to Figs. 9 to 10(B). Fig. 9 is an exploded view showing the energy absorbing device according to the fourth embodiment of the present invention. Fig. 10 is an explanatory view showing the energy absorbing device shown in Fig. 9, where (A) is a front view and (B) is a cross-sectional view of the shaft portion. Note that components that are the same as those in the above-described embodiments are designated by the same reference numerals, and redundant explanations will be omitted.

[0062] The energy absorbing device 1 according to the fourth embodiment is obtained by replacing the belt 2 of the energy absorbing devices 1 according to the first to third embodiments with a wire rope 200. The connecting member connected to the component that guides or restrains the webbing (belt anchor, guide anchor, buckle, etc.) is not limited to a strip-shaped fabric such as the belt 2, but can also be made of a metal wire rope.

[0063] As shown in Figures 9 to 10(B), the energy absorption device 1 includes a wire rope 200 connected to a component that guides or restrains the webbing, a first torsional deformation portion 4 that is arranged on the first end 301 side and is torsionally deformable under a predetermined load, a second torsional deformation portion 5 that is arranged on the second end 302 side and is torsionally deformable under a predetermined load, a connecting portion 303 that is arranged between the first torsional deformation portion 4 and the second torsional deformation portion 5, a first connecting portion 6 that is arranged on the end of the first torsional deformation portion 4 opposite to the connecting portion 303, and a second torsional deformation portion 7 that is arranged on the second end 302 side and is torsionally deformable under a predetermined load. the shaft member 300 including a second connecting portion 7 arranged at the end opposite the connecting portion 303 of the deformation portion 5; a cylindrical shaft portion 3 fixed to the connecting portion 303 and arranged on the outer periphery of the shaft member 300; a first fixing portion 81 to which the first connecting portion 6 is connected; a second fixing portion 82 to which the second connecting portion 7 is connected; a base 8 including a pair of bearing portions (a first bearing portion 83 and a second bearing portion 84) supporting both ends of the shaft portion 3; and a retaining washer 9 arranged at the end of the shaft member 300.

[0064] The wire rope 200 is wound around and fixed to the outer periphery of the shaft portion 3. Sleeves 204 for preventing the wire rope 200 from slipping off are fitted to both ends of the wire rope 200. A through hole 306 for inserting the wire rope 200 is formed in the connecting portion 303 of the shaft member 300. An opening 3a for inserting the wire rope 200 is formed in the shaft portion 3. The wire rope 200 is inserted into the opening 3a and the through hole 306 with the through hole 306 and the opening 3a aligned, and then wound around the outer periphery of the shaft portion 3.

[0065] The shaft member 300 has a first enlarged diameter portion 304 and a second enlarged diameter portion 305 formed on both ends of the connecting portion 303 and having a shape (e.g., a hexagonal shape) that can engage with the inner circumference of the shaft portion 3. The shaft member 300 has radially enlarged portions formed in the order of the first connecting portion 6, the first enlarged diameter portion 304, the second enlarged diameter portion 305, and the second connecting portion 7 from the first end portion 301 toward the second end portion 302. These portions are formed so that the diameters of the second connecting portion 7, the second enlarged diameter portion 305, the first enlarged diameter portion 304, and the first connecting portion 6 decrease in this order so that the shaft member 300 can be inserted into the base 8 and the shaft portion 3 from the second fixing portion 82 side.

[0066] The base 8 includes, for example, a first fixing portion 81 having a first opening 81a, a second fixing portion 82 having a second opening 82a, a first bearing portion 83 having a third opening 83a, a second bearing portion 84 having a fourth opening 84a, a side portion 85, and a fastening hole 87. The shape of the base 8 is not limited to the shape shown in the drawings.

[0067] Next, an energy absorbing device according to a fifth embodiment of the present invention will be described with reference to FIGS. 11 to 12(B). Here, FIG. 11 is a component exploded view showing the energy absorbing device according to the fifth embodiment of the present invention. FIG. 12 is an explanatory diagram showing the energy absorbing device shown in FIG. 11, where (A) is a front view and (B) is a cross-sectional view of the shaft portion. Note that components that are the same as those in the above-described embodiments are designated by the same reference numerals, and redundant description will be omitted.

[0068] The energy absorbing device 1 according to the fifth embodiment uses a wire rope 200 as a connecting part, similar to the fourth embodiment described above. In the fifth embodiment, a spool 400 around which the wire rope 200 is wound is disposed on the outside of the shaft portion 3.

[0069] The shaft member 300 has an expanded diameter portion having a shape (e.g., hexagonal) in which a connecting portion 303 disposed between the first torsional deformation portion 4 and the second torsional deformation portion 5 can engage with the inner periphery of the shaft portion 3. The radially expanded portion of the shaft member 300 is formed so that the diameters decrease in the order of the second connecting portion 7, the connecting portion 303, and the first connecting portion 6. The shaft portion 3 has a protrusion 3b formed on its outer periphery and extending in the axial direction, which can engage with the inner periphery of the spool 400.

[0070] The spool 400 is a cylindrical component having a length that can be accommodated between the first fixing portion 81 and the second fixing portion 82 of the base 8. A first fastening portion 403 for fastening the first end 201 of the wire rope 200 is formed on the first end 401 side of the spool 400, and a second fastening portion 404 for fastening the second end 202 of the wire rope 200 is formed on the second end 402 side of the spool 400. After the wire rope 200 is inserted, the first fastening portion 403 and the second fastening portion 404 are crimped and deformed to restrain the wire rope 200. Note that the method of fastening the wire rope 200 to the spool 400 is not limited to the configuration shown in the figure.

[0071] A guide groove 405 for winding the wire rope 200 may be formed on the surface of the spool 400. A recess 406 for engaging with the protrusion 3b of the shaft portion 3 is formed on the inner surface of the spool 400. The spool 400 may be made of a metal that is softer than the wire rope 200.

[0072] The first end 201 of the wire rope 200 is fixed to the first end 401 of the spool 400, the second end 202 of the wire rope 200 is fixed to the second end 402 of the spool 400, the wire rope 200 is wound from the first end 401 and the second end 402 of the spool 400 toward the center, and the folded portion 203 of the wire rope 200 is configured to be connected to a part that guides or restrains the webbing.

[0073] As shown in the fifth embodiment, by disposing the spool 400 as a part around which the wire rope 200 is wound, it is possible to increase the winding diameter of the wire rope 200, making it easier to wind the wire rope 200. Furthermore, by forming the guide groove 405, it is possible to easily wind the wire rope 200.

[0074] Furthermore, by fixing the first end 201 and the second end 202 of the wire rope 200 to the spool 400, winding the wire rope 200 around the spool 400 from both sides toward the center, and connecting it to other parts at the annular portion formed in the intermediate fold portion 203, it is possible to adjust the axial balance of the load applied to the spool 400 when a load is generated on the wire rope 200, and to suppress unbalanced loads on the axial parts including the spool 400.

[0075] The connecting members are not limited to the belt 2 and the wire rope 200, but may be, for example, string-like fabric or strip-like metal, or may be of other shapes and materials as long as they satisfy the specified conditions as connecting members, such as strength, durability, and corrosion resistance.

[0076] 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.

[0077] REFERENCE SIGNS LIST 1 Energy absorption device, 2 Belt, 3 Shaft portion, 3a Opening, 3b Protrusion portion, 4 First torsional deformation portion, 5 Second torsional deformation portion, 6 First connecting portion, 7 Second connecting portion, 8 Base, 9 Anti-slip washer, 21 Stitching portion, 30, 30a Shaft member, 31 First end portion, 32 Second end portion, 33 Slit, 34 First enlarged diameter portion, 35 Second enlarged diameter portion, 36 Connecting portion, 37 Belt pin, 37a Claw portion, 38 Recessed portion, 61 Groove portion, 71 Stopper, 81 First fixing portion, 81a First opening, 82 Second fixing portion, 82a Second opening, 83 First bearing portion, 83a Third opening, 84 Second bearing portion, 84a Fourth opening, 85 Side portion, 86 Top plate portion, 87 Fastening hole, 88 Insertion hole, 100 1. Seat belt device, 101 seat belt retractor, 102 guide anchor, 102a insertion hole, 102b belt guide, 103 belt anchor, 104 buckle, 104a buckle body, 105 tongue, 200 wire rope, 201 first end, 202 second end, 203 folded portion, 204 sleeve, 300 shaft member, 301 first end, 302 second end, 303 connecting portion, 304 first enlarged diameter portion, 305 second enlarged diameter portion, 306 through hole, 400 spool, 401 first end, 402 second end, 403 first fastening portion, 404 second fastening portion, 405 guide groove, 406 recess

Claims

1. An energy absorbing device that reduces a load acting on a webbing that restrains an occupant when the occupant is restrained, comprising: a belt connected to a part that guides or restrains the webbing; a shaft portion around which the belt is looped; a first torsional deformation portion disposed at a first end of the shaft portion and capable of torsional deformation under a predetermined load; a second torsional deformation portion disposed at a second end of the shaft portion and capable of torsional deformation under a predetermined load; a first connecting portion disposed at an end of the first torsional deformation portion opposite the shaft portion; a second connecting portion disposed at an end of the second torsional deformation portion opposite the shaft portion; a first fixed portion to which the first connecting portion is connected; a second fixed portion to which the second connecting portion is connected; a first bearing portion that supports the first end of the shaft portion; and a second bearing portion that supports the second end of the shaft portion, and a base fixed to a vehicle body.

2. The energy absorbing device according to claim 1, wherein the outer shape of the first connection portion is smaller than the outer shape of the shaft portion, and the outer shape of the second connection portion is larger than the outer shape of the shaft portion.

3. An energy absorbing device as described in claim 1, wherein the first fixing portion has a first opening into which the first connecting portion is fitted, the second fixing portion has a second opening into which the second connecting portion is fitted, the first bearing portion has a third opening through which the shaft portion can be inserted, and the second bearing portion has a fourth opening through which the shaft portion can be inserted, the third opening and the fourth opening being the same size, the first opening being smaller than the third opening and the fourth opening, and the second opening being larger than the third opening and the fourth opening.

4. The energy absorbing device according to claim 1, wherein the first torsional deformation portion and the second torsional deformation portion are formed thinner than the shaft portion.

5. The energy absorbing device as described in claim 1, wherein the shaft portion, the first torsional deformation portion, the second torsional deformation portion, the first connecting portion and the second connecting portion are integrally formed as a single axial member.

6. An energy absorption device as described in claim 1, wherein the first torsional deformation portion, the second torsional deformation portion, the first connecting portion and the second connecting portion are integrally formed as a single axial member, and the shaft portion has a cylindrical shape and is fixed to the outer periphery of the axial member.

7. An energy absorbing device as described in claim 1, wherein the shaft portion has a slit portion through which the belt can be inserted.

8. An energy absorbing device as described in claim 1, further comprising a belt pin having a slit formed on the outer periphery of said shaft portion through which said belt can be inserted.

9. An energy absorbing device for reducing a load acting on a webbing that restrains an occupant when the occupant is restrained, comprising: a wire rope connected to a part that guides or restrains the webbing; an axial member including a first torsional deformation portion arranged on a first end side and capable of torsional deformation under a predetermined load, a second torsional deformation portion arranged on a second end side and capable of torsional deformation under a predetermined load, a connecting portion arranged between the first torsional deformation portion and the second torsional deformation portion, a first connection portion arranged on an end of the first torsional deformation portion opposite the connection portion, and a second connection portion arranged on an end of the second torsional deformation portion opposite the connection portion; a cylindrical shaft portion fixed to the connecting portion and arranged on the outer periphery of the shaft member; and a base including a first fixing portion to which the first connection portion is connected, a second fixing portion to which the second connection portion is connected, and a pair of bearing portions that support both ends of the shaft portion, wherein the wire rope is wound around and fixed to the outer periphery of the shaft portion.

10. An energy absorbing device for reducing a load acting on a webbing that restrains an occupant when the occupant is restrained, comprising: a wire rope connected to a component that guides or restrains the webbing; an axial member including a first torsional deformation portion arranged at a first end side and capable of torsional deformation under a predetermined load, a second torsional deformation portion arranged at a second end side and capable of torsional deformation under a predetermined load, a connecting portion arranged between the first torsional deformation portion and the second torsional deformation portion, a first connection portion arranged at an end of the first torsional deformation portion opposite the connection portion, and a second connection portion arranged at an end of the second torsional deformation portion opposite the connection portion; a cylindrical shaft portion fixed to the connecting portion and arranged on the outer periphery of the axial member; a spool arranged on the outer periphery of the shaft portion; and a base including a first fixed portion to which the first connection portion is connected, a second fixed portion to which the second connection portion is connected, and a pair of bearing portions that support both ends of the shaft portion, wherein the wire rope is wound around and fixed to the outer periphery of the spool.

11. The energy absorbing device of claim 10, wherein a first end of the wire rope is secured to a first end of the spool, a second end of the wire rope is secured to a second end of the spool, the wire rope is reeled from the first and second ends of the spool toward a center portion, and a folded portion of the wire rope is configured to be connected to a component that guides or restrains the webbing.

12. The energy absorbing device according to claim 10, wherein the spool has a guide groove formed on a surface thereof for winding the wire rope therethrough.

13. An energy absorbing device for reducing a load acting on a webbing that restrains an occupant when the occupant is restrained, comprising: a connecting member connected to a part that guides or restrains the webbing; an axis member including: a first torsional deformation portion arranged on a first end side and capable of torsional deformation under a predetermined load, a second torsional deformation portion arranged on a second end side and capable of torsional deformation under a predetermined load, a connecting portion arranged between the first torsional deformation portion and the second torsional deformation portion, a first connecting portion arranged on an end of the first torsional deformation portion opposite the connecting portion, and a second connecting portion arranged on an end of the second torsional deformation portion opposite the connecting portion; a cylindrical shaft portion fixed to the connecting portion and arranged on the outer periphery of the shaft member; and a base including a first fixed portion to which the first connecting portion is connected, a second fixed portion to which the second connecting portion is connected, and a pair of bearing portions that support both ends of the shaft portion, wherein the connecting member is wrapped around and fixed to the outer periphery of the shaft portion.

14. The energy absorbing device of claim 1, claim 9, claim 10 or claim 13, wherein the energy absorbing device is part of a belt anchor, a guide anchor or a buckle.

15. A seat belt device comprising an energy absorbing device according to any one of claims 1 to 13.

16. The seat belt system of claim 15, wherein the energy absorbing device is a belt anchor, a guide anchor, or part of a buckle.

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