Cylindrical part fixing structure, method for manufacturing cylindrical part fixing structure, pretensioner, and seat belt

Abstract

Provide are: a cylindrical part fixing structure in which a cylindrical member is firmly fixed to a wire; and a method for manufacturing same. The cylindrical part fixing structure, in which a cylindrical member and a wire inserted in the cylindrical member are fixed, has a first pressing part protruding from one half side with respect to the axis of the cylindrical member, and a second pressing part protruding from the other half side, wherein the first pressing part and the second pressing part are positioned offset from each other in the axial direction. The wire positioned inside the cylindrical member is bent in an "S"-shape.

Description

Cylindrical portion fixing structure, manufacturing method of cylindrical portion fixing structure, pretensioner and seatbelt device

[0001] The present invention relates to a cylindrical portion fixing structure, a method for manufacturing the cylindrical portion fixing structure, a pretensioner, and a seatbelt device.

[0002] Vehicles such as automobiles are generally equipped with a seat belt device that restrains an occupant in a seat that has a seat on which the occupant sits and a backrest located behind the occupant. The seat belt device has a webbing that restrains the occupant, a retractor that winds up the webbing, a guide anchor that is provided on the vehicle body side to guide the webbing, a belt anchor that secures the webbing to the vehicle body side, a buckle that is provided on the side of the seat, and a tongue that is provided on the webbing, and the occupant is restrained in the seat by the webbing by fitting the tongue into the buckle.

[0003] Webbing used when restraining an occupant can be divided into a lap belt, which restrains the occupant's waist with the webbing between the belt anchor and tongue, and a shoulder belt, which restrains the occupant's shoulders diagonally with the webbing between the guide anchor and tongue.

[0004] Also, a seat belt device has been proposed in which a pretensioner capable of retracting a lap belt of webbing is disposed in a belt anchor.

[0005] The pretensioner includes, for example, a wire connected to the lap belt via a ferrule, a piston disposed at the end of the wire, a cylinder that slidably accommodates the piston, a gas generator that applies a driving force to the piston, and a housing that connects the cylinder and the gas generator so that they can communicate with each other.

[0006] The ferrule has a webbing connection portion at one end and a cylindrical wire connection portion at the other end. The wire is inserted into the cylinder and crimped from the outside to join the ferrule and wire.

[0007] Japanese Patent No. 6579520 Japanese Patent Application Laid-Open No. 2019-51860

[0008] The present invention aims to provide a cylindrical portion fixing structure in which a cylindrical member is firmly fixed to a wire, and a manufacturing method thereof. The present invention also aims to provide a pretensioner in which a wire and a ferrule are firmly connected, and a seatbelt device having this pretensioner.

[0009] The tubular portion fixing structure of the present invention is a tubular portion fixing structure that fixes a tubular member and a wire inserted into the tubular member, wherein a first compression portion protrudes from one half side of the axial center of the tubular member and a second compression portion protrudes from the other half side, and the first compression portion and the second compression portion are positioned offset in the axial direction.

[0010] The manufacturing method of the tube portion fixing structure of the present invention comprises the steps of inserting a wire into a cylinder, placing the cylinder with the wire inserted into a first groove of a first die and a second groove of a second die, and clamping the cylinder between the first die and the second die, and applying a pressing force to the cylinder from the first die and the second die to deform the cylinder while compressing the wire, and crimping the cylinder and the wire together, wherein a first convex portion is provided on the bottom surface of the first groove and a second convex portion is provided on the bottom surface of the second groove, the first convex portion and the second convex portion are offset in the longitudinal direction of the grooves, and the first convex portion and the second convex portion form a compression portion on the cylinder.

[0011] The pretensioner of the present invention is a pretensioner comprising a wire, a ferrule that connects one end of the wire to a webbing that restrains an occupant, a piston arranged on the other end side of the wire, a cylinder that slidably accommodates the piston, a gas generator that applies a driving force to the piston, and a housing that integrally connects the cylinder and the gas generator, wherein the ferrule has a cylindrical wire connection portion and a webbing connection portion extending from the wire connection portion, the wire connection portion and the wire inserted through the wire connection portion are fixed, a first compression portion protrudes from one half side of the axial center of the wire connection portion and a second compression portion protrudes from the other half side, and the first compression portion and the second compression portion are positioned offset in the axial direction.

[0012] The seatbelt device of the present invention is a seatbelt device including a webbing for restraining an occupant and a belt anchor for fixing the webbing to the vehicle body side, and the belt anchor includes the pretensioner of the present invention.

[0013] According to the present invention, the tubular member can be firmly fixed to the wire, and the wire and ferrule of the pretensioner can be firmly connected.

[0014] 11. An overall configuration diagram of a seatbelt device according to an embodiment. 12. A schematic configuration diagram of a pretensioner. 13. A schematic configuration diagram of a pretensioner. 14. A perspective view of a ferrule. 15. A perspective view of a crimping device according to an embodiment. 16. A view taken along arrow VI in FIG. 5. 17. A cross-sectional view taken along line VII-VII in FIG. 5. 18. A perspective view of a second die. 19. A diagram explaining a method of fixing a wire and a cylinder. 19. A cross-sectional view taken along line XX in FIG. 16. A cross-sectional view taken along line XII-XII in FIG. 17. A cross-sectional view taken along line XIII-XIII in FIG. 17. A cross-sectional view taken along line XIV-XIV in FIG. 17. A diagram showing a crimping device according to a modified example. 20. A cross-sectional view taken along a direction perpendicular to the axis of a fixing structure in which a cylinder is fixed to a wire. 21. A cross-sectional view taken along a direction perpendicular to the axis of a fixing structure in which a cylinder is fixed to a wire. 22. A cross-sectional view of a crimping device according to a modified example. 23. A cross-sectional view taken along the axial direction of a fixing structure in which a cylinder is fixed to a wire. 24. A perspective view of a tubular member. 25. A perspective view of a fixing structure in which a tubular member is fixed to a wire. 26. A perspective view of a U-shaped wire. 10A and 10B are perspective views of a fixing structure in which a tubular member is fixed to a wire, and FIG. 10C are perspective views of a fixing structure in which a tubular member is fixed to a wire.

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] Fig. 1 is a diagram showing the overall configuration of a seat belt device according to an embodiment of the present invention, in which, for the sake of convenience of explanation, components other than the seat belt device are shown by dashed lines.

[0017] 1 includes a webbing W for restraining an occupant, a 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 a seat S on which an occupant sits, and a tongue 105 provided on the webbing W. The belt anchor 103 is configured by a pretensioner 1, which will be described later. The pretensioner 1 is fixed to the vehicle body.

[0018] One end of the webbing W is connected to the retractor 101, and the other end is connected to the belt anchor 103. The middle portion of the webbing W is inserted into a tongue 105. By fitting the tongue 105 into a buckle 104, the occupant seated in the seat S can be restrained by the webbing W.

[0019] When restraining an occupant, the webbing W can be divided into a lap belt that restrains the occupant's waist with the webbing W between the belt anchor 103 and the tongue 105, and a shoulder belt that restrains the occupant's shoulders with the webbing W between the guide anchor 102 and the tongue 105.

[0020] The pretensioner 1 is activated in an emergency and retracts the webbing W (lap belt), thereby increasing the occupant restraining force of the webbing W.

[0021] As shown in FIG. 2 , the pretensioner 1 includes a wire 2, a piston 3 arranged on the wire 2, a cylinder 4 that slidably houses the piston 3, a gas generator 5 that applies a driving force to the piston 3, a housing 6 that integrally connects the cylinder 4 and the gas generator 5, and a bracket 7 that is connected to the housing 6 and positions the wire 2 (maintaining the bending angle).

[0022] The pretensioner 1 constitutes a belt anchor 103 and is fixed to the vehicle body by inserting bolts into fixing holes formed in the bracket 7 and the housing 6 .

[0023] A holder 21 is connected to one end of the wire 2, and the holder 21 is connected to a ferrule 22. The ferrule 22 connects an end of the webbing W to the wire 2. The webbing W connected to the wire 2 via the ferrule 22 constitutes a lap belt that restrains the waist of an occupant when the occupant is restrained.

[0024] The other end of the wire 2 is inserted into the housing 6 via the bracket 7 and connected to a wire end 23 inside the cylinder 4. A piston 3 is slidably disposed inside the cylinder 4, and the wire 2 is inserted into the piston 3 and then connected to the wire end 23. An O-ring 31 that improves airtightness is disposed on the outer periphery of the piston 3. In addition, a ball and ball ring 32 that suppresses backflow is disposed in the middle of the piston 3.

[0025] The gas generator 5 is connected to, for example, an acceleration sensor that detects a vehicle collision, and is activated in the event of a vehicle collision to eject high-pressure gas into the housing 6. The high-pressure gas ejected into the housing 6 presses the piston 3, causing the piston 3 to move in a direction away from the housing 6. As shown in Figure 3, as the piston 3 moves, the wire 2 is drawn into the housing 6 and the cylinder 4, tightening the webbing W (lap belt).

[0026] 4, the ferrule 22 has a cylindrical wire connecting portion 22a and a webbing connecting portion 22b extending from one end in the cylindrical axis (axial center) direction of the wire connecting portion 22. The webbing connecting portion 22b is a plate-like member having an opening 22c formed therein through which the webbing W is inserted.

[0027] With the wire 2 inserted through the other end of the wire connecting portion 22a, a pressure is applied from the outer circumferential surface of the wire connecting portion 22a to crimp (crimp) the ferrule 22 to fix the wire 2. The diameter of the wire 2 is approximately the same as the inner diameter of the wire connecting portion 22a.

[0028] Next, a description will be given of a method for crimping the wire connecting portion 22a onto the wire 2. A crimping device 50 as shown in Figs.

[0029] The crimping device 50 has a first die 51 and a second die 52. The first die 51 and the second die 52 are arranged opposite each other. In this embodiment, an example in which the first die 51 is arranged above the second die 52 will be described, but the arrangement direction of the first die 51 and the second die 52 is not limited to up and down, and may be left and right, etc.

[0030] Linearly extending grooves 51a, 52a are formed on the opposing surfaces of the first die 51 and the second die 52. That is, the groove 51a (first groove) is formed on the lower surface of the first die 51, and the groove 52a (second groove) is formed on the upper surface of the second die 52. As will be described later, the grooves 51a, 52a are spaces in which the cylindrical wire connection portion 22a is disposed, and the length L1 of the grooves 51a, 52a is longer than the length L2 of the wire connection portion 22a.

[0031] The grooves 51 a, 52 a have a width that narrows toward the bottom. In this embodiment, the grooves 51 a, 52 a have a trapezoidal cross section. The maximum width W of the grooves 51 a, 52 a is approximately the same as or slightly smaller than the outer diameter of the wire connection portion 22 a.

[0032] Convex portions (protrusions) 51b and 52b are provided on the bottom surfaces of the grooves 51a and 52a. The convex portion 51b (first convex portion) and the convex portion 52b (second convex portion) are provided at a predetermined interval D in the longitudinal direction of the grooves 51a and 52a.

[0033] At least one of the first die 51 and the second die 52 is connected to a moving mechanism such as an actuator and a pressure mechanism such as a pressure cylinder, so that the first die 51 and the second die 52 can be moved closer to or farther apart. For example, the second die 52 is fixed, and the first die 51 is movable up and down.

[0034] 9 and 10 , when the ferrule 22 is fixed to the wire 2, the wire connecting portion 22a through which the wire 2 is inserted is placed in the grooves 51a, 52a, and is sandwiched between the first die 51 and the second die 52. For ease of explanation, the webbing connecting portion 22b of the ferrule 22 is not shown.

[0035] A pressing force is applied to the wire connecting portion 22a from the first die 51 and the second die 52, compressing the wire 2 and deforming the wire connecting portion 22a, thereby crimping and fixing the wire connecting portion 22a and the wire 2 together.

[0036] 11 to 14 are cross-sectional views of a fixing structure 60 in which the wire connecting portion 22a is fixed to the wire 2. As shown in Fig. 11, the wire connecting portion 22a and the wire 2 are plastically deformed to fit the outer shapes of the protrusions 51b, 52b, and a first compression portion 61 protrudes from one half side and a second compression portion 62 protrudes from the other half side, sandwiching the axial center of the cylindrical wire connecting portion 22a.

[0037] The first compression portion 61 and the second compression portion 62 are offset in the axial direction of the cylindrical wire connection portion 22a, and the wire 2 bends in an S-shape following the deformation of the wire connection portion 22a. Due to the effect based on Euler's belt theory, the fastening force between the wire 2 and the wire connection portion 22a increases.

[0038] As shown in FIG. 12, in a cross section perpendicular to the axis of the cylindrical wire connecting portion 22a, the external shape of the wire connecting portion 22a deformed by crimping is approximately hexagonal.

[0039] Furthermore, as shown in Figures 13 and 14, in a cross section perpendicular to the axis of the cylindrical wire connection portion 22a, both sides 61a of the first compression portion 61 and both sides 62a of the second compression portion 62 function as ribs that prevent the inner diameter from expanding when the wire 2 and the wire connection portion 22a attempt to shift relative to each other.

[0040] In the above embodiment, the crimping of the ferrule 22 and the wire 2 has been described, but a similar method can be applied to crimping the wire 2 and the wire end 23. It can also be applied to crimping a cylindrical member other than the pretensioner 1 to a wire (wire rope). The above embodiment can be applied to, for example, high-strength joining of mechanical elements used under tension, such as wires, rods, and lines, and high-strength joining of a mechanical element used under tension, such as wires, rods, and lines, to another mechanical element. The cylindrical member and the wire are made of metal, and the material is not particularly limited.

[0041] In the above embodiment, the shape of the convex portions 51b, 52b provided on the first die 51 and the second die 52 of the crimping device 50 is not particularly limited, and convex portions having a hemispherical shape, a conical shape, or the like can be used.

[0042] The distance D between the protrusions 51b and 52b and the height of the protrusions 51b and 52b are preferably set to suitable values ​​depending on the diameter and material of the wire 2, the diameter and material of the cylindrical member, and the like.

[0043] In the above embodiment, the convex portions 51 b, 52 b are provided on the bottom surfaces of the grooves 51 a, 52 a, but the convex portions may be provided not only on the bottom surfaces but also on at least one of the side surfaces (inclined surfaces). For example, the convex portions may be provided so as to extend from one side surface to the other side surface via the bottom surface.

[0044] The number of protrusions 51b, 52b provided on the first die 51 and the second die 52 is not limited to one, and at least one of them may be two or more. That is, the protrusions may be crimped at two or more locations, with the positions alternately shifted vertically (or horizontally). Also, the protrusions 51b of the first die 51 or the protrusions 52b of the second die 52 may be omitted.

[0045] There is no particular limitation on the width of the convex portions 51b, 52b provided on the first die 51 and the second die 52. For example, as shown in Fig. 15, the width of the convex portions 51b, 52b may be the same as (approximately the same as) the width of the bottom surfaces of the grooves 51a, 52a. When the wire connection portion 22a and the wire 2 are crimped and fixed using the first die 51 and the second die 52 provided with such convex portions 51b, 52b, a first compression portion 61 and a second compression portion 62 are formed as shown in Figs. 16 and 17.

[0046] 18 , recesses 51c (first recesses) may be formed in the bottom surface of the grooves 51a of the first die 51 at positions facing the protrusions 52b of the second die 52. Similarly, recesses 52c (second recesses) may be formed in the bottom surface of the grooves 52a of the second die 52 at positions facing the protrusions 51b of the first die 51.

[0047] When the wire connection portion 22a and the wire 2 are crimped and fixed using the first die 51 and the second die 52 having such recesses 51c, 52c, the wire connection portion 22a and the wire 2 are plastically deformed to fit the shapes of the convex portions 51b, 52b and the recesses 51c, 52c, and as shown in Figure 19, a first protrusion 63 is formed on the opposite side of the first compression portion 61 across the axis of the wire connection portion 22a, and a second protrusion 64 is formed on the opposite side of the second compression portion 62.

[0048] In the above embodiment, a configuration in which one wire is fixed to a tubular member has been described, but two or more wires may be used. For example, as shown in Figures 20 and 21 , two wires 71 can be inserted into a tubular member 70 and sandwiched between a first die 51 and a second die 52, thereby crimping and fixing the tubular member 70 to the two wires 71. Compression portions 65 are formed at offset positions in the axial direction of the tubular member 70, and the tubular member 70 and the two wires 71 are firmly fixed together.

[0049] The outer peripheral surface and the inner peripheral surface of the cylindrical member 70 are continuous and are formed of smooth surfaces without discontinuities, such as curved surfaces, flat surfaces, or a combination thereof.

[0050] The two wires may be U-shaped wires 72 formed by bending a single wire into a U-shape as shown in Fig. 22. By inserting both ends (both sides) of the U-shaped wire 72 into the tubular member 70 and sandwiching it between the first die 51 and the second die 52, the tubular member 70 and both ends of the U-shaped wire 72 can be crimped and fixed together as shown in Fig. 23. Compressed portions 66 are formed at positions offset from each other in the axial direction of the tubular member 70, and the tubular member 70 and the U-shaped wire 72 are firmly fixed together.

[0051] As shown in FIG. 24, three wires, each having a U-shaped wire 72 and a wire 71 disposed between both ends thereof, may be crimped and fixed to a cylindrical member 70 .

[0052] The present invention is not limited to the above-described embodiments, and the components can be modified and embodied in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments. For example, some components may be omitted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined.

[0053] REFERENCE SIGNS LIST 1 Pretensioner 2 Wire 3 Piston 4 Cylinder 5 Gas generator 6 Housing 7 Bracket 22 Ferrule 23 Wire end 50 Crimping device W Webbing

Claims

1. A cylindrical portion fixing structure that fixes a cylindrical member and a wire inserted into the cylindrical member, wherein a first compression portion protrudes from one half of the axial center of the cylindrical member and a second compression portion protrudes from the other half, and the first compression portion and the second compression portion are offset in the axial direction.

2. The cylindrical portion fixing structure according to claim 1, wherein the wire positioned inside the cylindrical member is bent in an S-shape.

3. A tubular portion fixing structure as described in claim 1, wherein the tubular member has a first protrusion on the opposite side of the first compression portion and a second protrusion on the opposite side of the second compression portion, across the axis.

4. The cylindrical portion fixing structure according to claim 1, wherein a plurality of wires are inserted through the cylindrical member.

5. A method for manufacturing a tube fixing structure, comprising: a step of inserting a wire into a cylinder; a step of placing the cylinder with the wire inserted into a first groove of a first die and a second groove of a second die, and sandwiching the cylinder between the first die and the second die; a step of applying a pressing force to the cylinder from the first die and the second die to deform the cylinder while compressing the wire, and crimping the cylinder and the wire; wherein a first convex portion is provided on the bottom surface of the first groove and a second convex portion is provided on the bottom surface of the second groove, the first convex portion and the second convex portion are offset in the longitudinal direction of the grooves, and a compression portion is formed on the cylinder by the first convex portion and the second convex portion.

6. A method for manufacturing a tube portion fixing structure as described in claim 5, wherein a first recess is provided in a position on the bottom surface of the first groove facing the second convex portion, and a second recess is provided in a position on the bottom surface of the second groove facing the first convex portion.

7. A pretensioner comprising: a wire; a ferrule connecting one end of the wire to a webbing that restrains an occupant; a piston arranged on the other end side of the wire; a cylinder that slidably accommodates the piston; a gas generator that applies a driving force to the piston; and a housing that integrally connects the cylinder and the gas generator, wherein the ferrule has a cylindrical wire connection portion and a webbing connection portion extending from the wire connection portion, the wire connection portion and the wire inserted into the wire connection portion are fixed, a first compression portion protrudes from one half side of the axial center of the wire connection portion and a second compression portion protrudes from the other half side, and the first compression portion and the second compression portion are positioned offset in the axial direction.

8. A seatbelt device comprising a webbing for restraining an occupant and a belt anchor for fixing the webbing to the vehicle body, wherein the belt anchor is equipped with the pretensioner according to claim 7.

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