JP6301883B2 - Seat belt retractor - Google Patents

Description

  The present invention relates to a seat belt retractor, and more particularly to a seat belt retractor including a pretensioner.

In recent seat belt retractors, in the event of an emergency such as a vehicle collision, the pretensioner is operated to forcibly wind up the seat belt and remove the slack of the seat belt (see, for example, Patent Documents 1 and 2). ). The pretensioner described in Patent Literatures 1 and 2 includes a pipe, a gas generator provided on one end side of the pipe, a piston, a plurality of balls as a moving body, and a pinion connected to a spindle. And it is known that a ball is wound up by rotating a spindle through a pinion by pressing a ball through a piston with high pressure gas generated from a gas generator by combustion of explosives at the time of a vehicle collision. Yes.
As another pretensioner, a moving body in which a viscous body is filled in a pipe is known (see, for example, Patent Document 3).

JP 2001-151077 A JP 2001-301666 A Japanese Patent No. 4051149

  In the pretensioners described in Patent Documents 1 and 2, a metal ball, which is a hard material, is used as a mass body that transmits a driving force to the pinion. For this reason, the pretensioner can only transmit the compressive force between the balls, and further improvement is required in order to obtain a higher output pretensioner. In addition, the degree of freedom of the shape of the drive unit such as a pipe is limited, and it is difficult to reduce the size of the pretensioner. On the other hand, although the pretensioner described in Patent Document 3 can increase the degree of freedom of the shape of the drive unit, the transmission force is reduced and there is room for improvement.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a seat belt retractor capable of obtaining a pretensioner with high driving force transmission efficiency and reduced size and high output. There is.

The above object of the present invention can be achieved by the following constitution.
(1) a spindle for winding up a seat belt;
A pretensioner that rotates the spindle in the winding direction by gas pressure by burning of explosives;
With
The pretensioner is
A gas generator for generating the gas pressure;
A rotating member that rotates integrally with the spindle;
A tube member disposed around the rotating member and attached to the gas generator at one end thereof;
A plurality of drive members housed in the tube member and pressed by gas pressure generated by the gas generator, and a seat belt retractor,
2. The seat belt retractor according to claim 1, wherein the drive member is a granular body having a size capable of existing in a plurality of cross sections of the tube member.
(2) The seat belt retractor according to (1), wherein an area of the cross section inside the tube member gradually decreases from the gas generator toward the rotating member.
(3) The seat belt retractor according to (1), wherein an area of the cross section inside the tube member is increased at a curved portion of the tube member.
(4) The seat belt retractor according to any one of (1) to (3), wherein the granular body is deformable by being pressed by the gas pressure.
(5) The seat belt retractor according to any one of (1) to (4), wherein a plurality of protrusions protruding outward are formed on a surface of the granular body.
(6) The seat belt retractor according to any one of (1) to (5), wherein the granular body is any one of a columnar shape, a disk shape, a spherical shape, a ring shape, and a cylindrical shape. .
(7) The granular material is any one of (1) to (5), wherein at least two kinds of granular materials are mixed among a columnar shape, a disk shape, a spherical shape, a ring shape, and a cylindrical shape. The seat belt retractor described in 1.
(8) The seat belt retractor according to any one of (1) to (7), wherein the granular body is made of resin.
(9) Any one of (1) to (8), wherein a plurality of recesses that can be engaged with at least one of the granular bodies are formed on the outer peripheral surface of the rotating member over the entire circumference. Crab seat belt retractor.
(10) The seat belt retractor according to (9), wherein the concave portion is a groove formed on an outer peripheral surface of the rotating member along a central axis direction of the rotating member.
(11) The seat belt retractor according to (10), wherein the groove is a groove having a V-shaped cross section.
(12) A cross-sectional shape of the V-shaped groove has a first surface that extends in a radial direction of the rotating member and on which the granular body acts, and a second surface that is inclined with respect to a tangential direction of the outer peripheral surface of the rotating member. The seat belt retractor as set forth in (11), characterized by comprising:
(13) The seat belt retractor according to (10), wherein the groove is a U-shaped groove in cross section.
(14) The seat belt retractor according to (9), wherein the recess is a recess formed on an outer peripheral surface of the rotating member and recessed toward the center.
(15) The seat belt retractor, wherein the plurality of recesses have a plurality of different shapes selected from (9) to (14), and are formed on the outer peripheral surface of the rotating member.
(16) A piston that receives a pressure of gas from the gas generator is provided between the granular body on the one end side of the pipe member and the gas generator. (15) The seat belt retractor according to any one of (15).
(17) The seat belt retractor according to (16), wherein the piston includes an elastic material capable of following a change in the cross section of the pipe member.
(18) Before the operation of the gas generator, a stopper for closing the inside of the pipe member is provided on the rotating member side of the pipe member so that the granular material does not leak. The seat belt retractor according to any one of (17).
(19) The seat belt retractor according to (18), wherein the stopper includes an elastic material.
(20) The other end side of the pipe member includes a collection container for storing the discharged granular material,
The seatbelt retractor according to any one of (1) to (19), wherein the internal volume of the collection container is expandable when the granular material is accommodated.
(21) Before the operation of the gas generator, the collection container is held in a folded state, and is configured to expand and deploy from the folded state when the gas generator is operated. The seat belt retractor according to (20), characterized in that
(22) The seat belt retractor according to (20) or (21), wherein the collection container is formed to include an elastic material.

The “cross section” of the present invention represents a section orthogonal to the center line along the longitudinal direction of the pipe member.
In addition, the “elastic material” included in the piston of the present invention is composed of a single resin or a plurality of resins such as rubber and elastomer.
Furthermore, the “elastic material” included in the stopper of the present invention is also composed of a single resin or a plurality of resins such as rubber and elastomer.
In addition, the “elastic material” included in the collection container of the present invention is also composed of a resin such as rubber or elastomer, and in particular, the gas generator is in a contracted or folded state before the operation, and the internal volume after the operation is It is preferable that it is a material which can expand.

  According to the seat belt retractor of the present invention, a pretensioner that presses a plurality of driving members by gas pressure generated by burning explosives and acts on a rotating member that rotates integrally with the spindle to rotate the spindle in the winding direction. Is provided. The drive member is a granular body having a size that allows a plurality of drive members to exist in the cross section of the tube member that houses the drive member. Thereby, a gas pressure can be efficiently transmitted to a rotating member via a granular material, and the pretensioner in which size reduction and high output are achieved is obtained.

It is sectional drawing of the seatbelt retractor which concerns on one Embodiment of this invention. (A) is the II-II sectional view taken on the line of FIG. 1, (b) is sectional drawing along the BB line of (a). It is a perspective view of various granular materials which are drive members. It is a principal part side view of the various rotation member in which the some recessed part which can be engaged with a granular material was formed in the outer peripheral surface, (a) is a principal part side view of the rotation member provided with several other V-shaped groove | channel, (B) is a principal part side view of the rotation member provided with the some U-shaped groove | channel, (c) is a principal part perspective view of the rotation member provided with the several hollow dented toward a center direction. It is sectional drawing of the pretensioner which concerns on the modification of this invention. It is sectional drawing of the pretensioner which concerns on the other modification of this invention. It is a fragmentary sectional view of the pretensioner for demonstrating operation | movement of the piston of FIG.

  Hereinafter, a seat belt retractor according to an embodiment of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, a seat belt retractor 10 according to an embodiment of the present invention is rotatably supported by a retractor frame 11, a spindle 12 for winding a webbing (not shown), and a spindle 12 mounted in the spindle 12. 12, a torsion bar 13 extending along the axial center of 12 and having one axial end coupled to the spindle 12, and a tread head 14 coupled to the other axial end of the torsion bar 13. The torsion bar 13 constitutes a force limiter mechanism for feeding out the webbing while absorbing energy when a load more than the setting is applied to the webbing in a state where the tread head 14 is locked by a locking means (not shown).

  The retractor frame 11 is made of metal, and includes a first side plate 15 located on the left side and a second side plate 16 located on the right side in FIG. A pretensioner 20 and a winding spring device (not shown) are attached to the first side plate 15, and the second side plate 16 includes sensors such as vehicle acceleration detection means and webbing pull-out acceleration detection means. Locking means (not shown) is provided for engaging the tread head 14 with the retractor frame 11 in an emergency to prevent rotation of the webbing in the pulling direction.

  As shown in FIGS. 1 and 2, the pretensioner 20 includes a pinion 21 as a rotating member, a tube pipe (tube member) 22 as a guide member, and a plurality of resin-made granular bodies 23 as drive members, And a gas generator (MGG) 24 which is a gas pressure generating means.

  The pinion 21 is always coupled to the axial end portion of the spindle 12 by spline fitting, and rotates together with the spindle 12. In addition, a V-shaped groove 25 </ b> A that is a concave portion 25 that engages with the granular material 23 and converts the linear movement of the granular material 23 into the rotational motion of the pinion 21 is provided along the circumferential direction on the outer peripheral portion of the pinion 21. Are provided.

  The tube pipe 22 is a pressure vessel member, is curved in a substantially U shape so as to surround the periphery of the pinion 21, is continuously formed from one end 26 to the other end 27, and the side plate 15 of the retractor frame 11. It is fixed to. A gas generator 24 is attached to one end 26 of the tube pipe 22. A plurality of granular materials 23 are accommodated in the tube pipe 22.

  The tube pipe 22 is provided with an opening 28 formed by cutting out a part of the wall corresponding to the pinion 21. A part of the outer peripheral portion of the pinion 21 formed with a plurality of V-shaped grooves 25 </ b> A extending in the circumferential direction protrudes into the tube pipe 22 in the opening 28. The gap between the opening 28 and the outer periphery of the pinion 21 is small enough to prevent the granular material 23 from leaking out. Each V-shaped groove 25A is formed along the axial direction.

  The tube pipe 22 is formed in a tapered shape so that the cross-sectional area of the cross section S inside the tube pipe 22 gradually decreases from the one end 26 toward the opening 28. A collecting container 29 for collecting the granular material 23 is disposed at the other end 27 on the downstream side of the opening 28.

  The granular material 23 has such a size that a plurality of granular materials 23 can exist in the cross section S inside the tube pipe 22. As shown in FIG. 3 (a), the granular body 23 of the present embodiment has an uneven shape (so-called konpei-sugar) in which a plurality of protrusions 23a are formed on the surface of a substantially spherical resin body. Shaped granular material 23A. Here, the fact that a plurality of particles can exist in the cross section S inside the tube pipe 22 means that a part of the plurality of granular materials 23 exist even in the narrowest cross section S upstream of the pinion 21. Intended. For example, the granular material 23 includes one having a diameter equal to or smaller than ½ of the cross-sectional diameter of the narrowest cross section S upstream of the pinion 22 of the tube pipe 22.

  The gas generator 24 is electrically connected to an unillustrated MGG connector and a control circuit. When the gas generator 24 is ignited through the MGG connector, gas is generated by combustion of explosives. Thus, the plurality of granular materials 23 are pressed by the gas pressure of the gas generator 24 and can move in the tube pipe 22 in the direction of the pinion 21.

  The operation of this embodiment will be described. As shown in FIG. 2, in the seat belt retractor 10 of the present invention, the gas generator 24 is ignited and high-pressure gas is generated by the combustion of explosives when the acceleration sensor detects the acceleration of the vehicle equal to or greater than a predetermined value, such as during a vehicle collision. Thereby, the gas pressure in the tube pipe 22 rises, the plurality of granular materials 23 are pressed by the high pressure gas, and move in the tube pipe 22 toward the pinion 21.

  At this time, since the area of the cross section S of the tube pipe 22 is tapered so as to gradually decrease from the one end 26 toward the pinion 21, the plurality of granular bodies 23 gradually become granular as they approach the pinion 21. When the density of the bodies 23 increases and the granular bodies 23 reach the pinions 21, the density is high so that the high-pressure gas pressure is sufficiently transmitted to the pinions 21.

Further, the resin-made granular bodies 23 can be individually deformed, and the plurality of granular bodies 23 are gradually deformed as they approach the pinion 21 to ensure higher fluidity while ensuring the fluidity in the tube pipe 22. The pinion 21 can be reached in a dense state. Furthermore, the shearing force of the protrusion 23 a can be used as the rotational force of the pinion 21 in addition to the force of compressing the granular body 23 due to the hooking of the plurality of protrusions 23 a of the granular body 23.
In addition, due to the fluidity of the granular material 23, it is possible to easily cope with a complicated shape of the tube pipe 22.

  The plurality of granular bodies 23 that are dense and dense are engaged with a V-shaped groove 25 </ b> A (concave portion 25) provided on the outer peripheral portion of the pinion 21, and the linear movement of the granular body 23 is converted into the rotational movement of the pinion 21. Convert and rotate the pinion 21. The rotation of the pinion 21 is transmitted to the spindle 12 that is spline-fitted and winds up the webbing that is fixed to the spindle 12.

And the granular material 23 which rotationally driven the pinion 21 is discharged | emitted in the collection container 29 from the other end 27 of the tube pipe 22, and is collect | recovered. At this time, since the mass of each granular material 23 made of resin is small, the kinetic energy is also small. Therefore, the collection container 29 can be made of a material having a relatively low strength such as a resin such as rubber or elastomer, thereby reducing the cost.
The collection container 29 is held in a folded state before the operation of the gas generator 24 to reduce the internal volume, and is expanded and deployed from the folded state when the gas generator 24 is operated, so that the internal volume is increased. May be configured to expand. Thereby, the vehicle space occupied by the collection container 29 can be used more efficiently than the collection container having an internal volume for collecting the granular material 23 in advance.

  Thus, even if the same gas generator as the conventional one is used, a high output pretensioner can be obtained, and the size can be reduced.

  Moreover, since the granular material 23 as a drive member is solid, even if there is a gap in the tube pipe 22, it does not leak out if it is a gap smaller than the granular material 23. In comparison, the production of the tube pipe 22 and peripheral members is facilitated. Further, by appropriately changing the cross-section S of the tube pipe 22, it is possible to increase the speed and amplify the force as in the case of the hydraulic equipment.

  As described above, according to the seat belt retractor 10 of the present embodiment, the plurality of granular materials 23 are pressed by the gas pressure generated by the explosive burning, and act on the pinion 21 that rotates integrally with the spindle 12. A pretensioner 20 that rotates 12 in the winding direction is provided. Further, since the granular body 23 is a granular body having a size that can exist in a plurality of cross sections S inside the tube pipe 22 that accommodates the granular body 23, the gas pressure is efficiently reduced through the granular body 23. The pretensioner 20 having a small size and a high output can be obtained.

  Further, since the cross-sectional area inside the tube pipe 22 gradually decreases from the gas generator 24 toward the pinion 21, the density of the granular material 23 gradually increases as the granular material 23 approaches the pinion 21, and the granular material 23. Since the pinion 21 is rotated in a state where the gas density is high, the gas pressure can be transmitted to the pinion 21 more efficiently.

  Further, since the granular material 23 can be deformed by being pressed by the gas pressure, it can reach the pinion 21 in a higher density state while ensuring fluidity in the tube pipe 22.

  Furthermore, since a plurality of projecting portions 23 a projecting outward are formed on the surface of the granular material 23, the shearing force of the projecting portions 23 a is also used as the rotational force of the pinion 21 due to the catching between the plurality of projecting portions 23 a. be able to.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimensions, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

For example, the granular material 23 is not limited to the above-described concavo-convex granular material 23A (see FIG. 3A), but a cylindrical granular material 23B (FIG. 3B), a disk-shaped granular material 23C ( 3 (c)), spherical granular material 23D (FIG. 3 (d)), ring-shaped granular material 23E (FIG. 3 (e)), cylindrical granular material 23F (FIG. 3 (e)), etc. It can be of any shape. Furthermore, these granular materials 23 (23B, 23C, 23D, 23E, and 23F) may be provided with a plurality of protrusions 23a that protrude outward from their surfaces, like the concavo-convex granular materials 23A.
Moreover, the granular material 23 may be formed in a granular shape as long as it does not leak from the opening 28 of the tube pipe 22.

  Further, the granular body 23 includes an uneven granular body 23A, a cylindrical granular body 23B, a disk-shaped granular body 23C, a spherical granular body 23D, a ring-shaped granular body 23E, a cylindrical granular body 23F, and At least two types of granular materials 23 can be mixed from the granular materials 23 provided with a plurality of protrusions 23 a on the surface of the granular materials 23. Further, the granular material 23 may be flexible so as to be deformable by being pressed by the gas pressure generated by the gas generator 24.

  Moreover, the recessed part 25 formed in the outer peripheral surface of the pinion 21 so that engagement with the granular material 23 should just be a shape which can transmit the driving force of the granular material 23, and is not limited to the V-shaped groove | channel 25A shown in FIG. . For example, as shown to Fig.4 (a), it extends in the radial direction of the pinion 21B, the 1st surface 25a which the granule 23 acts on, and the 2nd surface 25b which inclines with respect to the tangential direction of the outer peripheral surface of the pinion 21B, , Other V-shaped grooves 25B.

  Moreover, as shown in FIG.4 (b), the cross-sectional U-shaped groove | channel 25C formed in the outer peripheral surface of pinion 21C may be sufficient, and as shown in FIG.4 (c), it is center direction from the outer peripheral surface of pinion 21D. A plurality of depressions (dimples) 25 </ b> D that are recessed toward the surface may be used. Furthermore, at least two types of recesses 25 may be mixed from the V-shaped groove 25A, the other V-shaped groove 25B, the U-shaped groove 25C, and the recess 25D.

  Furthermore, the pretensioner of the present invention can be modified as in the modification shown in FIG. 5 and other modifications shown in FIG.

  That is, like the pretensioner 20 shown in FIGS. 5 and 6, a piston 30 that receives the pressure of the gas from the gas generator 24 is provided between the granular body 23 and the gas generator 24 on one end side of the tube pipe 22. 30A may be provided. In this case, the pistons 30 and 30 </ b> A can transmit the gas pressure received from the gas generator 24 to the granular material 23.

  Note that the material of the pistons 30 and 30A is preferably an elastic material that can follow the change in the cross section S of the tube pipe 22, and includes a resin such as rubber, silicon, and elastomer.

  Furthermore, in the modification shown in FIG. 6, the piston 30A may be formed in a mortar shape (substantially truncated cone shape). For example, as shown in FIG. Even in the case where the piston 30A changes so as to be thicker than other portions, the diameter of the piston 30A may be increased while moving to prevent gas leakage. Piston 30A can expand an outer diameter by receiving the pressure of gas in a mortar-shaped part. Thereby, it can change following the inside diameter change of the tube pipe 22, can minimize the gas leak, and can transmit the gas pressure to the granular material 23 with the maximum efficiency.

Further, as shown in FIGS. 5 and 6, a stopper 31 for closing the inside of the tube pipe 22 is provided on the pinion 21 side of the tube pipe 22 so that the granular material 23 does not leak before the operation of the gas generator 24. Also good. The stopper 31 prevents the granular material 23 from coming out of the tube pipe 22 in the initial state (when the gas generator 24 is not operated), and prevents the rotating member 21 and the granular material 23 from contacting each other. After the operation of the gas generator 24, the stopper 31 is formed in such a size that the stopper 31 moves through the tube pipe 22 and is discharged and collected by the collection container 29.
In addition, the material of the stopper 31 includes a resin such as rubber, silicon, and elastomer.

In the above-described embodiment shown in FIG. 2 and the modification shown in FIG. 5, the shape of the tube pipe 22 is set so that the area of the cross section S gradually decreases from the one end 26 toward the pinion 21. The shape of the tube pipe 22 can be changed according to the layout and the granular material 23.
For example, like the tube pipe 22 shown in FIG. 7, by increasing the cross-sectional area of the portion 22a curved toward the pinion 21 (for example, the inner diameter D), the granular material 23 can be easily deformed, and the pinion can be efficiently produced. 21 may be rotated. By doing so, the fluidity of the granular material at the curved portion of the tube pipe 22 is improved, and the efficiency during operation of the pretensioner can be further increased.
Further, the root portion 22b to which the piston 30A moves may be formed in a tapered shape so as to gradually become thicker.

10 Seat belt retractor 12 Spindle 20 Pre-tensioners 21, 21B, 21C, 21D Pinions (rotating members)
22 Tube pipe (tube member)
23, 23A, 23B, 23C, 23D, 23E, 23F Granules (drive member)
23a Projection 24 Gas Generator (Gas Generator)
25 Recess 25A V-shaped groove (recess)
25B Other V-shaped grooves (recesses)
25C U-shaped groove (recess)
25D depression (concave)
25a First surface 25b Second surface S Cross section of pipe member

Claims (22)

A spindle that winds up the seat belt;
A pretensioner that rotates the spindle in the winding direction by gas pressure by burning of explosives;
With
The pretensioner is
A gas generator for generating the gas pressure;
A rotating member that rotates integrally with the spindle;
A tube member disposed around the rotating member and attached to the gas generator at one end thereof;
A plurality of drive members housed in the tube member and pressed by gas pressure generated by the gas generator, and a seat belt retractor,
2. The seat belt retractor according to claim 1, wherein the drive member is a granular body having a size capable of existing in a plurality of cross sections of the tube member.   The seat belt retractor according to claim 1, wherein an area of the cross section inside the tube member gradually decreases from the gas generator toward the rotating member.   The seat belt retractor according to claim 1, wherein an area of the cross section inside the tube member increases at a curved portion of the tube member.   The seat belt retractor according to any one of claims 1 to 3, wherein the granular body is deformable by being pressed by the gas pressure.   The seatbelt retractor according to any one of claims 1 to 4, wherein a plurality of protrusions protruding outward are formed on a surface of the granular body.   The seat belt retractor according to any one of claims 1 to 5, wherein the granular body is any one of a columnar shape, a disc shape, a spherical shape, a ring shape, and a cylindrical shape.   6. The granular material according to claim 1, wherein at least two kinds of the granular materials are mixed among a cylindrical shape, a disk shape, a spherical shape, a ring shape, and a cylindrical shape. Seat belt retractor.   The seat belt retractor according to any one of claims 1 to 7, wherein the granular material is made of resin.   The plurality of concave portions that can be engaged with at least one of the granular bodies are formed on the outer peripheral surface of the rotating member over the entire circumference. Seat belt retractor.   The seat belt retractor according to claim 9, wherein the recess is a groove formed on an outer peripheral surface of the rotating member along a central axis direction of the rotating member.   The seat belt retractor according to claim 10, wherein the groove is a groove having a V-shaped cross section.   The cross-sectional shape of the V-shaped groove includes a first surface that extends in the radial direction of the rotating member, on which the granular material acts, and a second surface that is inclined with respect to the tangential direction of the outer peripheral surface of the rotating member. The seat belt retractor according to claim 11.   The seat belt retractor according to claim 10, wherein the groove is a groove having a U-shaped cross section.   The seat belt retractor according to claim 9, wherein the recess is a recess formed on an outer peripheral surface of the rotating member and recessed toward the center.   The plurality of recesses have a plurality of different shapes selected from claims 9 to 14, and are formed on the outer peripheral surface of the rotating member in a mixed manner.   The piston which receives the pressure of the gas from the said gas generator is provided between the said granular material in the said one end part side of the said tube member, and the said gas generator, Any one of Claims 1-15 characterized by the above-mentioned. The seat belt retractor according to claim 1.   The seat belt retractor according to claim 16, wherein the piston includes an elastic material capable of following a change in the cross section of the pipe member.   18. The stopper according to claim 1, further comprising a stopper that closes the inside of the pipe member so that the granular material does not leak before the gas generator is activated. The seat belt retractor according to claim 1.   The seat belt retractor according to claim 18, wherein the stopper includes an elastic material. The other end side of the tube member is provided with a collection container for containing the discharged granular material,
The seatbelt retractor according to any one of claims 1 to 19, wherein an inner volume of the collection container is expandable when the granular material is accommodated.   Before the operation of the gas generator, the collection container is held in a folded state, and is configured to expand and deploy from the folded state when the gas generator is operated. The seat belt retractor according to claim 20.   The seat belt retractor according to claim 20 or 21, wherein the collection container is formed to include an elastic material.

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