WO2014181652A1 - Pretensioner and seat belt device equipped with same - Google Patents

Abstract

[Problem] To form a smaller and more compact pretensioner, thereby increasing the degree of installation freedom, while quickly and effectively applying the required tension to the seatbelt during an emergency. [Solution] By means of a pressure gas generated by a gas generator (14) during an emergency, a piston (15) generates pressing force, thereby pressing an arc-shaped seatbelt pressing member (12a). Consequently, the seatbelt pressing member (12a) breaks open a stopper (25) and moves along a circular trajectory which is concentric with or substantially concentric with a curved part (13b) of a pipe (13). Thus, the seatbelt pressing member (12a) presses the front end part (4c) of the seatbelt (4), so the seatbelt (4) is pulled and the front end part (4c) thereof is pulled into a frame (9) while being bent into a U shape. Accordingly, the seatbelt (4) tightens, thereby increasing the restraining force the passenger.

Description

Pretensioner and seat belt device provided with the same

The present invention relates to a technical field of a pretensioner that increases the restraining force of an occupant by a seat belt (particularly, a lap belt) by pulling the seat belt with pressure gas at an early stage of an emergency such as a vehicle collision, and a vehicle seat belt apparatus. It belongs to the technical field.

Conventionally, various seat belt devices equipped with a pretensioner have been developed for seat belt devices installed in vehicles such as automobiles. This pretensioner pulls the seat belt with the pressure gas generated by the gas generator in the early stage of an emergency in which a deceleration larger than a normal deceleration is applied to the vehicle, such as when a vehicle collides. Thus, the slack of the seat belt is quickly removed and tension is applied to the seat belt to increase the restraining force of the occupant by the seat belt. In that case, the seat belt that restrains the occupant is divided into a shoulder belt that restrains the shoulder and chest of the occupant and a lap belt that restrains the occupant's waist.

As an example of a conventional pretensioner, various pretensioners that apply tension to a seat belt by directly pulling a lap belt with a piston that is operated by pressure gas in an emergency have been developed (see, for example, Patent Documents 1 and 2). .

The pretensioner described in Patent Documents 1 and 2 includes a linear cylinder, a piston that is slidably disposed in the cylinder, and that is coupled to one end of the lap belt via a flexible coupling member. And a gas generator for generating pressure gas for driving the piston in the cylinder in an emergency. When the piston is driven by the pressure gas generated by the gas generator in an emergency, the piston pulls the lap belt toward the cylinder, so that tension is applied to the seat belt, thereby restraining the occupant's restraining force by the seat belt. Enhanced.

However, in the pretensioners described in Patent Documents 1 and 2, the amount of movement of the piston is small because the length of the linear cylinder on which the piston moves is relatively short. Also, the piston simply pulls the lap belt. For this reason, since the pull amount of the lap belt is small, it is difficult for the pretensioner to apply the necessary tension to the seat belt quickly and effectively in an emergency. Therefore, it is conceivable to increase the amount of movement of the piston by making the length of the linear cylinder as long as possible. However, if the length of the cylinder is simply increased, the pretensioner becomes large.

On the other hand, a flexible connecting member having one end connected to the buckle and the other end fixed to the housing, a pulley over which the connecting member is movably bridged, and a slidable arrangement in a linear cylinder. A piston that is provided, a linear rigid piston rod that is connected to the piston and has a movable pulley rotatably disposed at the tip thereof, and a gas generator that generates pressure gas for driving the piston in the cylinder in an emergency A pretensioner (so-called buckle pretensioner) is proposed (for example, see Patent Document 3).

In the pretensioner described in Patent Document 3, the moving pulley at the tip of the piston rod is brought into contact with the connecting member between the other end of the connecting member and the pulley at the normal time when the pretensioner does not operate. Then, when the piston is driven by the pressure gas generated by the gas generator in an emergency, the movable pulley presses the connecting member. Then, the connecting member is pulled while being bent in a U shape, and the buckle is pulled. Accordingly, the seat belt is pulled through the tongue engaged with the buckle, and the restraining force of the occupant by the seat belt is increased. In that case, in the pretensioner described in Patent Document 3, since the connecting member is pulled while being bent in a U shape, the amount of pulling in of the buckle increases with respect to the amount of movement of the piston.

Furthermore, as another example of a conventional pretensioner, a belt take-up shaft for taking up a belt band connected to a buckle, a flexible drive cable for rotationally driving the belt take-up shaft, and sliding in a pipe There has been proposed a pretensioner provided with a piston that can be arranged and pulls the drive cable, and a gas generator that generates pressure gas that drives the piston in a pipe in an emergency (see, for example, Patent Document 4).

In the pretensioner described in Patent Document 4, the piston is driven by the pressure gas generated by the gas generator in an emergency. Then, the belt pulls the belt band by rotating the belt winding shaft by the piston pulling the drive cable. Accordingly, when the buckle is pulled, the seat belt is pulled through the tongue engaged with the buckle, and the restraining force of the occupant by the seat belt is increased. Since the drive cable used in the pretensioner described in Patent Document 4 is flexible, the piston trajectory is lengthened by curving the piston trajectory by curving the pipe on which the piston moves. As a result, the amount of movement of the piston can be increased.

Therefore, it is conceivable to apply the above-described technical matter of pulling the connecting member in the pretensioner described in Patent Document 3 while bending it in a U-shape to the pretensioner described in Patent Document 1 or 2. That is, by pulling the lap belt described in Patent Document 1 or 2 while being bent in a U shape by the piston, it is conceivable to increase the pull amount of the lap belt with respect to the same movement amount of the piston. In addition to this, it is conceivable to apply the above-mentioned technical matter for bending the pipe of the pretensioner described in Patent Document 4 to curve the piston orbit to the pretensioner described in Patent Document 1 or 2. That is, it is conceivable that the linear cylinder described in Patent Document 1 or 2 is bent and lengthened to increase the amount of movement of the piston while suppressing an increase in the size of the pretensioner.

Japanese Patent Application Laid-Open No. 2004-322739. JP 2010-913. Japanese Patent Laid-Open No. 2001-97183. JP-T 2009-512583.

However, in the pretensioner described in Patent Document 3, a linear cylinder is used as in the pretensioner described in Patent Document 1 or 2. For this reason, the movement amount of the piston is relatively small as in the case of the pretensioner described in Patent Documents 1 and 2 described above. Therefore, even if the amount of pulling in of the buckle increases with respect to the amount of movement of the piston by bending the connecting member in a U shape as described above, it cannot be said that the amount of movement of the piston is sufficiently large. Further, if the cylinder length is simply increased in the same manner as described above in order to increase the movement amount of the piston, the pretensioner becomes large.

In the pretensioner described in Patent Document 4, a structure is adopted in which the driving force of the piston is transmitted to the belt winding shaft via the driving cable, and the belt winding shaft winds the driving cable. That is, a motion conversion structure is adopted in which the linear motion of the piston is converted into the rotational motion of the belt winding shaft. For this reason, although the movement amount of the piston can be increased, not only the pretensioner becomes large but also the structure of the pretensioner becomes complicated due to another reason that the motion conversion structure is adopted. Moreover, due to this motion conversion structure, the driving energy of the piston is not effectively converted into the rotational energy of the belt winding shaft, and the energy loss increases. For this reason, it is difficult for the pretensioner to quickly and effectively give the necessary tension to the seat belt in an emergency.

In addition, even if the pretensioners described in Patent Documents 3 and 4 are combined and applied to the pretensioner described in Patent Document 1 or 2, the pretensioner described in Patent Document 3 uses a flexible connecting member by a piston. Since it pulls by pressing, the flexible drive cable described in Patent Document 4 cannot simply be used in place of the piston rod of the pretensioner described in Patent Document 3. Therefore, it is difficult to increase the movement amount of the piston while suppressing an increase in the size of the pretensioner. For this reason, a pretensioner becomes large-sized, and not only does the pretensioner have a large installation space, but also the pretensioner installation location is limited. In particular, since the seat belt device is disposed in a narrow vehicle interior, if the installation place of the pretensioner is limited, the degree of freedom of installation of the pretensioner becomes relatively low.

The present invention has been made in view of such circumstances. The purpose of the present invention is to make the pretensioner more compact and compact while providing a seat belt with the necessary tension in an emergency quickly and effectively. To provide a pretensioner and a seat belt device capable of increasing the degree of freedom of installation.

In order to solve the above-described problems, a pretensioner according to the present invention is provided with a pipe having at least an arc-shaped curved portion, a wrapping portion provided so as to be movable along a circular orbit concentric with or substantially concentric with the curved portion of the pipe. A seat belt pressing member that tensions the seat belt by pressing the front end portion of the seat belt from the front side of the belt, a gas generator that generates gas in an emergency, and a gas generator that is movably provided in the pipe and It comprises at least a piston that generates a pressing force that operates with gas pressure to press the seat belt pressing member.

Further, in the pretensioner according to the present invention, the seat belt pressing member is provided such that at least a part thereof is formed in an arc shape and at least a part of the arc-shaped part is movable in the curved portion of the pipe. It is characterized by.
Furthermore, the pretensioner of the present invention is characterized by including a seat belt pressing member stopper that keeps the seat belt pressing member in a non-operating state in a normal state and that enables the seat belt pressing member in an emergency.

Furthermore, the pretensioner of the present invention comprises a container-like frame having the seat belt entrance for allowing the seat belt to enter the pipe and the seat belt pressing member. A member presses the front end of the seat belt and pulls it into the internal space of the frame through the seat belt entrance, thereby tensioning the seat belt.

The pretensioner according to the present invention further includes a seatbelt connected member to which the seatbelt is connected in the internal space of the frame, and the seatbelt connected member is eccentric from the center of the arc of the curved portion of the pipe. It is characterized by being provided at the position.
Furthermore, the pretensioner of the present invention is characterized by including a lock member that locks at least the movement of the seat belt pressing member in the direction opposite to the pressing direction with respect to the front end portion of the seat belt at the end of the operation.

Furthermore, the pretensioner of the present invention includes a lock member that locks at least the movement of the seat belt pressing member in a direction opposite to the pressing direction with respect to the front end portion of the seat belt at the end of the operation, and the locking member is provided on the frame. It is provided at the position of the seat belt entrance.
Furthermore, the pretensioner of the present invention is characterized by including a pretensioner rotation preventing mechanism for preventing the pretensioner from rotating.

Furthermore, the pretensioner of the present invention is provided with an arc-shaped force transmission member that is at least partially movable in the curved portion of the pipe and that can press the seat belt pressing member, and the piston is pressed by the pressing force of the piston. The seat belt pressing member is pressed through a force transmission member.

Further, in the pretensioner according to the present invention, the seat belt pressing member presses the front end portion of the seat belt that has entered the internal space from the seat belt entrance, and the front end portion of the seat belt enters the seat belt. Before entering the mouth, the surface of the tip is turned from the vehicle left-right direction to the vehicle front-rear direction with the pretensioner installed.

Further, the pretensioner according to the present invention is characterized in that a part of a front end portion of the seat belt pressed by the seat belt pressing member is folded along a longitudinal direction of the seat belt.
Furthermore, the pretensioner of the present invention is characterized in that the folded portion of the front end portion of the seat belt is folded in a spiral shape.
Furthermore, the pretensioner of the present invention is characterized in that the folded portion of the front end portion of the seat belt is folded in a serpentine manner.

Further, in the pretensioner according to the present invention, the folded portion of the front end portion of the seat belt is folded along the longitudinal direction of the front end portion toward the center in the width direction of the front end portion. It is characterized by being.
Furthermore, the pretensioner of the present invention is characterized in that the folded portion of the front end portion of the seat belt is sewn and held.

Furthermore, in the pretensioner of the present invention, when the seat belt pressing member presses the front end portion of the seat belt, the unretained portion of the front end portion is folded in the same folding as the folded portion of the front end portion. And a seat belt guide member for guiding the non-retained portion of the tip portion.

Furthermore, the pretensioner of the present invention is characterized by comprising a guide member that guides the seat belt pressing member so that the seat belt pressing member moves along the circular orbit.
Furthermore, the pretensioner of the present invention is characterized in that the guide member has an arm portion that guides the seat belt pressing member to move along the circular orbit by rotating.

On the other hand, the seat belt device of the present invention is a seat belt that restrains an occupant, a seat belt retractor that winds up the seat belt, a tongue that is slidably supported by the seat belt, and the tongue is detachable. It has at least a buckle to be locked and a pretensioner for pulling the seat belt in an emergency, and the pretensioner is any one of the pretensioners of the present invention described above.

According to the pretensioner and the seat belt apparatus of the present invention configured as described above, the seat belt pressing member is pressed by the pressing force of the piston and moves along the circular orbit of a concentric circle or a substantially concentric circle with the curved portion of the pipe. Then, the front end of the seat belt is pressed. Accordingly, the seat belt pressing member is tensioned by pulling the seat belt in an arc shape. At this time, since the seat belt pressing member moves along the circular orbit described above, it is possible to increase the movement amount of the seat belt pressing member, that is, the movement amount of the piston. As a result, the tension amount of the seat belt also increases, so that the tension required in an emergency can be quickly and effectively applied to the seat belt. Further, since the seat belt pressing member pulls the seat belt in an arc shape, it is possible to prevent the pretensioner from becoming large even if the movement amount of the piston increases. That is, it becomes possible to form the pretensioner in a compact and compact manner. Therefore, the degree of freedom of installation of the pretensioner can be effectively increased.

Also, a pretensioner rotation prevention mechanism is provided. Thereby, even if a rotational force is applied to the pretensioner, the rotation of the pretensioner can be prevented. Therefore, the rotation of the pretensioner due to the gas pressure when the pretensioner is activated and the rotation of the pretensioner due to the inertial force of the occupant after the pretensioner is activated can be prevented, and the restraint action of the occupant by the pretensioner is more effective. Can be demonstrated.

Further, a seat belt connected member provided in the internal space of the frame and connected to the seat belt is provided at a position eccentric from the center of the arc of the curved portion of the pipe. As a result, it is possible to effectively increase the length of the overlapping portion of the front end portion of the seat belt wound around the seat belt connected member. Therefore, it is possible to increase the bonding strength of the overlapping portion of the front end portion of the seat belt.
Furthermore, since the lock member is provided at the seat belt entrance position in the frame, the lock member can be assembled more easily.

Further, the seat belt guide structure for guiding the seat belt is formed by the seat belt guide member of the seat belt being pressed by the seat belt pressing member and being drawn into the inner space of the frame by an axial seat belt guide member. Can be simplified.

Further, before the front end of the seat belt enters the seat belt entrance, the surface of the front end is turned from the vehicle left-right direction to the vehicle front-rear direction with the pretensioner installed. The front end of the seat belt that has entered the interior space from the belt entrance is pressed. Therefore, the pretensioner can be installed so that the thickness direction thereof is the left-right direction of the vehicle. Thereby, while being able to install a pretensioner in the side surface of a vehicle seat, it can suppress that a pretensioner protrudes in a vehicle left-right direction.

Furthermore, a part of the front end portion of the seat belt pressed by the seat belt pressing member is folded along the longitudinal direction of the seat belt, so that the width of the front end portion pressed by the seat belt pressing member is smaller than the width of the seat belt. Can be set to width. Thereby, the thickness of the pretensioner can be further reduced, and the pretensioner can be further reduced in size and size. Therefore, even if the pretensioner is installed on the side surface of the vehicle seat, the pretensioner can be more effectively suppressed from projecting in the left-right direction of the vehicle, and the pretensioner can be The possibility of getting in the way can be reduced. In this way, it is possible to efficiently use the dead space in the vehicle interior, and the degree of freedom of installation of the pretensioner can be further effectively increased.

Further, by guiding the non-retained portion of the front end portion of the seat belt by the seat belt guide member, when the seat belt pressing member presses the front end portion of the seat belt, the non-retained portion of the front end portion Can be folded in the same fold as the folded portion of the tip. Accordingly, the width of the front end portion of the seat belt pressed by the seat belt pressing member can be easily reduced with a simple configuration including only the seat belt guide member.

Further, the guide member is guided so that the seat belt pressing member moves along a circular orbit concentric with or substantially concentric with the center of the bending portion of the pipe, so that the force transmission member also moves along the circular orbit in the bending portion of the pipe. It becomes possible to guide along. Thereby, when the force transmission member moves in the pipe, the friction between the seat belt pressing member and the tip portion and the friction between the force transmission member and the inner peripheral surface of the pipe can be suppressed. Therefore, the seat belt pressing member and the force transmission member can be moved more smoothly. Therefore, the energy of the gas can be effectively used, and the seat belt can be pulled efficiently and quickly tensioned. As a result, occupant restraint by the seat belt can be effectively improved.

It is a figure which shows typically the seatbelt apparatus using the 1st example of embodiment of the pretensioner concerning this invention. (A) is the perspective view which looked diagonally back from the vehicle front of the pretensioner of the 1st example, (B) is the perspective view which looked diagonally forward from the vehicle rear of this pretensioner. (A) is a front view of the pretensioner of the first example, (B) is a top (plan) view of the pretensioner, and (C) is a left side view of the pretensioner. (A) is a longitudinal sectional view taken along the line VIA-VIA in FIG. 3 (B) of the pretensioner when not activated, and (B) is a longitudinal sectional view of the pretensioner when the operation is completed. (A) is a figure explaining the unlocking of the locking member of this pretensioner, (B) is a figure explaining the locking of the locking member of this pretensioner. (A) is a partial plan view of the folding part of the seat belt as viewed from the arrow VIA in FIG. 1 and FIG. 4 (A), (B) is a sectional view taken along the line VIB-VIB in (A), and (C) is FIG. 6 is a view similar to FIG. 2A showing a second example of the embodiment of the pretensioner of the present invention, FIG. 4D is a cross-sectional view taken along the line VID-VID in FIG. It is sectional drawing similar to (D) which shows the 3rd example of embodiment of a tensioner. (A) is a disassembled perspective view which shows the 4th example of embodiment of the pretensioner of this invention, (B) is an enlarged view of the VIIB part in (A). (A) is the perspective view seen from the attachment side of the pretensioner of the 4th example, (B) is the perspective view seen from the attachment side of the pretensioner of the 4th example. (A) is a front view of the pretensioner of the fourth example, and (B) is a left side view of the pretensioner of the fourth example. FIG. 9A is a longitudinal sectional view taken along line XA-XA in FIG. 9A of the pretensioner when not activated, and FIG. 9B is a longitudinal sectional view of the pretensioner when the operation is completed. (A) is a partial expanded sectional view explaining the state which does not perform locking operation by the locking member of the 4th example, (B) is a partial enlarged sectional view explaining the state where locking operation by the locking member of the 4th example is performed. .

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
FIG. 1 is a view schematically showing a seat belt device using a first example of an embodiment of a pretensioner according to the present invention.

As shown in FIG. 1, the seat belt device 1 of the first example is basically the same as a conventionally known three-point seat belt device. In the figure, in a conventionally known configuration, 1 is a seat belt device, 2 is a vehicle seat, 3 is a seat belt retractor disposed in the vicinity of the vehicle seat 2, and 4 is formed by webbing and can be pulled out to the seat belt retractor 3 The seat belt 5 is wound around the seat belt and restrains the occupant M in an emergency, 5 is a guide anchor for guiding the seat belt 4 pulled out from the seat belt retractor 3 toward the shoulder of the occupant M, and 6 is guided from the guide anchor 5. A tongue 7, which is slidably supported by the seat belt 4, is a buckle fixed to the floor of the vehicle body or the vehicle seat and into which the tongue 6 is detachably inserted. The seat belt 4 includes a shoulder belt 4a that restrains the shoulder and chest of the occupant M and a lap belt 4b that restrains the waist and the like of the occupant M.
The seatbelt 4 mounting operation and mounting release operation in the seatbelt apparatus 1 are the same as those of a conventionally known seatbelt apparatus.

Further, as shown in FIG. 1, the seat belt device 1 of the first example does not constitute the front end portion 4c of the seat belt 4 pulled out from the seat belt retractor 3 (that is, does not constitute the lap belt 4b of the seat belt 4). The portion continuing from 4b to the tip side is connected to the pretensioner 8. The pretensioner 8 is arranged and fixed to the vehicle seat 2 on the side opposite to the buckle 7 with respect to the vehicle seat 2. The pretensioner 8 operates in the initial stage of the above-mentioned emergency in the same way as a conventionally known pretensioner, pulls the lap belt 4b and is tensioned, and restrains the occupant M by the seat belt 4 (particularly, the lap belt 4b). It is something to increase.

FIG. 2A is a perspective view of the pretensioner of the first example viewed obliquely from the front of the vehicle, and FIG. 2B is a perspective view of the pretensioner viewed obliquely from the rear of the vehicle. 3A is a front view of the pretensioner, FIG. 3B is a top (plan) view of the pretensioner, and FIG. 3C is a left side view of the pretensioner. Further, FIG. 4A is a longitudinal sectional view of the pretensioner when not activated, and FIG. 4B is a longitudinal sectional view of the pretensioner when the operation is finished.

As shown in FIGS. 2A and 2B, FIGS. 3A to 3C, and FIGS. 4A and 4B, the pretensioner 8 of the first example includes a frame 9, a support shaft 10, Seat belt connected member 11, seat belt tension member 12, pipe 13, gas generator 14, piston 15, lock member 16, force transmission member 17, seat belt guide roller 18, inner periphery side seat belt guide portion 19, and outer periphery side A seat belt guide portion 20 is provided.

The frame 9 has a substantially cylindrical first frame member 9a and a second frame member 9b. The first and second frame members 9a and 9b are substantially flat and substantially cylindrical containers having a predetermined thickness by joining their arc-shaped peripheral walls to each other so as to be contactable / separable or non-contactable / separable by appropriate coupling means. It is formed in a shape. A frame 9 is configured. The pretensioner 8 is installed such that the substantially flat surface of the second frame member 9b contacts the side surface of the vehicle seat 2. In the state where the pretensioner 8 is installed on the vehicle seat 2, the thickness direction of the pretensioner 8 is the left-right direction of the vehicle.

This frame 9 forms a substantially cylindrical internal space. The first frame member 9a and the second frame member 9b have a large opening 9c that communicates the internal space with the outside (the opening of the second frame member 9b is not shown, but the opening of the first frame member 9a is not shown). 9c) is formed. A seat belt entrance 9d is formed on the outer peripheral surfaces of the first and second frame members 9a and 9b. The front end 4c of the seat belt 4 enters the inner space through the seat belt entrance 9d. In that case, the front end portion 4c of the seat belt 4 has the surface of the front end portion 4c turned approximately 90 degrees from the vehicle left-right direction before reaching the seat belt entrance 9d and is directed in the vehicle front-rear direction 9d. To enter.

The support shaft 10 is formed of, for example, a bolt or the like, and is located at the approximate center of the circular shape of the first and second frame members 9a and 9b between the first and second frame members 9a and 9b in the internal space of the frame 9. Located and erected. The seat belt connected member 11 is disposed between the first frame member 9a and the second frame member 9b and supported and fixed to the support shaft 10, and a part of the front end portion 4c of the seat belt 4 is connected. The

The seat belt tensioning member 12 includes a seat belt pressing member 12a that presses the seat belt 4 and a guide member 12b that operates the seat belt pressing member 12a. The seat belt pressing member 12a is formed by bending a belt-like plate into a U shape. On the other hand, the guide member 12b has first and second arm portions 12c and 12d extending in the radial direction and a connecting portion 12e for connecting one end sides of the first and second arm portions 12c and 12d. The belt-like plate is bent in a U shape. The other end sides of the first and second arm portions 12c and 12d are supported by the seat belt connected member 11 so as to be rotatable within the openings formed in the first frame member 9a and the second frame member 9b. Has been. The seat belt pressing member 12a is attached to the connecting portion 12e so that the curved portion protrudes from the connecting portion 12e by a predetermined amount. When the seat belt pressing member 12a moves (rotates), the first and second arm portions 12c and 12d rotate to be guided by the first and second arm portions 12c and 12d, thereby supporting shafts. It moves (rotates) along a circular orbit concentric with the center of 10. Thus, the seat belt pressing member 12a presses the seat belt 4.

The pipe 13 includes a linear portion 13a and a curved portion 13b extending from the linear portion 13a and formed in a concentric or substantially concentric arc shape with the center of the support shaft 10. In that case, the seat belt pressing member 12a moves along a circular orbit concentric with or substantially concentric with the center of the bending portion 13b. The gas generator 14 is disposed in the straight portion 13 a of the pipe 13 and operates in an emergency to generate pressure gas in the pipe 13. The piston 15 is slidably disposed in the linear portion 13 a of the pipe 13. The piston 15 is operated by the pressure gas generated by the gas generator 14 to generate a pressing force.

The lock member 16 is slidably disposed in a boundary portion between the linear portion 13a and the curved portion 13b of the pipe 13. The lock member 16 includes a first lock body 16a and a predetermined number of lock balls 16b. The first lock body 16a has an annular recess 16c having a substantially triangular cross section along the axial direction. In that case, as shown in FIGS. 5A and 5B, the inclined surface 16d of the recess 16c on the side of the force transmission member 17 (opposite to the piston 15 side) is a relatively gentle inclined surface. A predetermined number of locking balls 16b are disposed in the recess 16c.

The first lock body 16a of the lock member 16 is moved in the pipe 13 by being pressed by the pressing force of the piston 15. In this case, as shown in FIG. 5A, when the first lock body 16a is about to move in the direction of arrow A (the direction of the force transmission member 17), each locking ball 16b is positioned at the deepest position of the recess 16c. Located in a relatively deep position. Thereby, it does not pinch between the inclined surface 16d of the recessed part 16c of the 1st lock main body 16a, and the internal peripheral surface 13c of the pipe 13. FIG. At this time, the first lock body 16a is movable in the pipe 13. Further, as shown in FIG. 5B, when the lock member 16 is about to move in the direction of the arrow B (the direction of the piston 15), each locking ball 16b is connected to the inclined surface 16d of the recess 16c and the inside of the pipe 13. It is pinched between the peripheral surface 13c. At this time, due to the wedge effect between the inclined surface 16d and the inner peripheral surface 13c, the clamping force of each locking ball 16b increases, and the lock member 16 performs the locking action of the first lock body 16a. As a result, the first lock body 16a is locked in the direction of the arrow B, and cannot move in the pipe 13 in the same direction.

The force transmission member 17 is formed by bending a relatively long circular arc from a rod (round bar) of a rigid body such as metal (substantially not deformed when the pressing force is transmitted from the piston 15) and of the pipe 13. The curved portion 13b is slidably disposed. In this case, the force transmission member 17 is disposed concentrically with the center of the support shaft 10. The force transmission member 17 is rotated by the lock member 16 along the circular orbit concentric with the center of the support shaft 10 in the pipe 13. A protrusion 17 a is provided at the tip of the force transmission member 17 (the end opposite to the end on the lock member 16 side). The protrusion 17a is fitted into the U-shaped seat belt pressing member 12a so as to press the seat belt pressing member 12a when the force transmission member 17 is operated. In that case, as described above, the seat belt pressing member 12a is guided by the first and second arm portions 12c and 12d, so that the force transmission member 17 is also guided along the aforementioned circular orbit. As a result, the friction between the seat belt pressing member 12a and the tip end portion 4c and the friction between the force transmission member 17 and the inner peripheral surface of the pipe 13 are suppressed, and the seat belt pressing member 12a and the force transmission member 17 are Move more smoothly.

The seat belt guide roller 18 is rotatably installed between the outer peripheral edges of the first and second frame members 9a and 9b. In that case, the seat belt guide roller 18 is disposed on one end side of the seat belt entrance 9d. The seat belt guide roller 18 guides the seat belt 4 while rotating. As shown in FIGS. 6 (A) and 6 (B), when the pretensioner 8 is in an inoperative state, the first and second frames of the front end portion 4c of the seat belt 4 immediately before entering the seat belt entrance 9d. The portions that have entered the internal space of the members 9a and 9b are arranged along the longitudinal direction of the seat belt 4 such that both side edges in the longitudinal direction of the distal end portion 4c abut or substantially abut toward the center in the width direction of the distal end portion 4c. It is folded and stitched to retain the folded shape shown in FIG. 6 (B).

As a result, the width W ₁ of the distal end portion 4c in the stitched portion 4d is set to one half or substantially one half of the normal width W ₀ of the lap belt 4b defined by law (W ₁ = W _0/2 or _{W 1 ≒ W 0/2)} . As shown in FIG. 4A, when the pretensioner 8 is not operated, the stitching portion 4d is brought into contact with the seat belt guide roller 18. The first and second frame members 9a, spacing the facing inner surface of 9b is set to approximately 1/2 of the width W ₀ of the lap belt 4b.
In addition, the part of the seat belt 4 retained in a folded shape can be retained by bonding with, for example, an adhesive.

The inner periphery side seat belt guide part 19 and the outer periphery side seat belt guide part 20 are installed between the first and second frame members 9a and 9b, respectively. Each of the inner peripheral seat belt guide portion 19 and the outer peripheral seat belt guide portion 20 is formed in an arc shape concentric with the center of the support shaft 10. The seat belt 4 that has entered the interior space of the frame 9 from the seat belt entrance 9d has the arc-shaped outer peripheral surface of the inner peripheral seat belt guide portion 19 and the arc-shaped inner periphery of the outer peripheral seat belt guide portion 20. It is guided by the surface. In the first example, the outer periphery side seat belt guide portion 20 is integrally provided as a single member with the second frame member 9b.

Next, the operation of the pretensioner 8 of the first example will be described. As shown in FIG. 4 (A), the front end 4c of the seat belt 4 has a seat belt pressing member between the seat belt guide roller 18 and the inner periphery side seat belt guide 19 at the normal time when the gas generator 14 does not operate. The belt 12 is pressed by 12a so as to contact the seat belt guide roller 18 and the inner periphery side seat belt guide portion 19 and bend slightly. Further, although not shown, the piston 15, the lock member 16, and the force transmission member 17 are held at the positions shown in FIG. 4A by appropriate urging means as in the conventional pretensioner. In this case, each locking ball 16b is located at a relatively deep position in the recess 16c shown in FIGS. 4A and 5A, and the lock member 16 can slide in the pipe 13.

In this state, the seat belt 4 is attached to the occupant M by engaging the tongue 6 with the buckle 7 as in the conventional general seat belt device as shown in FIG. When the gas generator 14 is activated and generates pressure gas in an emergency in a state where the seat belt 4 is mounted on the occupant M in this way, the gas pressure of the pressure gas acts on the piston 15. Then, the piston 15 is activated to generate a pressing force, and the seat belt pressing member 12 a of the seat belt tensioning member 12 is pressed through the lock member 16 and the force transmission member 17. As a result, the seat belt pressing member 12a presses the front end portion 4c of the seat belt 4, so that the seat belt 4 is pulled while the front end portion 4c is bent in a U shape, and the first and second frame members 9a, 9b. Drawn into the interior space. In that case, the front end portion 4c of the seat belt 4 is guided by pressure contact with the seat belt guide roller 18, and both longitudinal edges of the front end portion 4c are guided in the folding direction by the first and second frame members 9a and 9b. As shown in FIGS. 6 (A) and 6 (B), the distal end portion 4c follows the distal end portion 4c portion where the stitching portion 4d is formed, and both side edges in the longitudinal direction of the distal end portion 4c. It enters into the internal space of the first and second frame members 9a, 9b while being folded so as to contact or substantially contact toward the center in the width direction.

Furthermore, the piston 15, the lock member 16, and the force transmission member 17 move along a circular orbit concentric with the center of the support shaft 10. At this time, the first and second arm portions 12c and 12d rotate counterclockwise in FIG. 4A around the support shaft 10, but the first and second arm portions 12c and 12d rotate to rotate the seat. The belt pressing member 12a is guided along the aforementioned circular orbit, and the force transmission member 17 is also guided along the aforementioned circular orbit by guiding the seat belt pressing member 12a in this way. Thereby, even if the force transmission member 17 is formed relatively long, the friction between the seat belt pressing member 12a and the tip end portion 4c and the friction between the force transmission member 17 and the inner peripheral surface 13c of the pipe 13 are suppressed. Thus, the seat belt pressing member 12a and the force transmission member 17 move more smoothly. Therefore, the energy of the pressure gas is effectively used, the seat belt 4 is pulled efficiently and is tensioned relatively quickly, and the restraint of the occupant M by the seat belt 4 (particularly, the lap belt 4b) is effectively increased. .

Further, the front end portion 4c of the seat belt 4 that has been bent into a U-shape and entered into the internal space of the first and second frame members 9a and 9b is guided on the inner peripheral side thereof by the inner peripheral side seat belt guide portion 19. And the outer peripheral side thereof is guided by the outer peripheral side seat belt guide portion 20. In that case, the front end 4c of the seat belt 4 is bent in a U shape, so that the amount of tension of the seat belt 4 is greater than the amount of movement of the seat belt pressing member 12a (that is, the amount of movement of the piston 15). Therefore, the restraining force of the occupant M by the seat belt 4 (particularly the lap belt 4b) is effectively increased in a short time with a smaller movement amount of the piston 15.

The seat belt pressing member 12a, the force transmission member 17, the lock member 16, and the piston 15 are stopped when moving to the maximum stroke position at which the restraining force of the occupant M becomes a preset restraining force. Thereby, the initial restraint of the passenger | crew M by the pretensioner 8 is complete | finished. At this time, each locking ball 16b moves to the inclined surface 16d side. On the other hand, after the restraint of the occupant M by the pretensioner 8 ends, the seat belt 4 tends to be pulled due to the inertia of the occupant M, so that the front end portion 4c tends to be pulled toward the lap belt 4b. The lock member 16 is urged in the direction of arrow B shown in FIG. 5B by the pulling force of the distal end portion 4c via the seat belt pressing member 12a and the force transmission member 17, and tries to move in the same direction. At this time, each locking ball 16b locks the first lock body 16a in the B direction by the wedge effect described above, so that the first lock body 16a cannot move in the B direction. As a result, the seat belt pressing member 12a and the force transmission member 17 also cannot move in the direction B, and the seat belt 4 does not extend even if it is pulled by the inertia of the occupant M. Restrained by

According to the pretensioner 8 and the seat belt apparatus 1 of the first example, the arc-shaped force transmission member 17 is pressed by the piston 15 to move in the curved portion 13b of the pipe 13 so that the seat belt pressing member 12a is moved. When pressed, the seat belt pressing member 12a presses the front end 4c of the seat belt 4 and pulls the seat belt 4 in an arc shape. At this time, the arc-shaped force transmission member 17 moves in the curved portion 13b of the pipe 13, but since the pipe 13 is curved in an arc shape, the movement amount of the force transmission member 17, that is, the movement amount of the piston 15 is reduced. It can be increased. As a result, the amount of tension of the seat belt 4 also increases, so that the tension required in an emergency can be quickly and effectively applied to the seat belt 4. Further, since the seat belt pressing member 12a pulls the seat belt 4 in an arc shape, it is possible to suppress the pretensioner 8 from becoming large even if the movement amount of the piston 15 increases. That is, the pretensioner 8 can be formed small and compact. Therefore, the degree of freedom of installation of the pretensioner 8 can be effectively increased.

Further, before the front end 4c of the seat belt 4 enters the seat belt entrance 9d of the frame 9, the surface of the front end 4c is turned from the vehicle left-right direction to the vehicle front-rear direction with the pretensioner 8 installed. The belt pressing member 12a presses the front end portion 4c of the seat belt 4 that has entered the internal space from the seat belt entrance 9d. Therefore, the pretensioner 8 can be installed so that the thickness direction thereof is the left-right direction of the vehicle. Thereby, while being able to install in the side surface of the pretensioner 8 vehicle seat 2, it can suppress that the pretensioner 8 protrudes in the vehicle left-right direction.

Furthermore, a part of the front end portion 4c of the seat belt 4 pressed by the seat belt pressing member 12a is folded along the longitudinal direction of the seat belt 4, whereby the width W of the front end portion 4c pressed by the seat belt pressing member 12a. ₁ can be set to a width smaller than the width W ₀ of the seat belt 4. Thereby, the thickness of the pretensioner 8 can be further reduced, and the pretensioner 8 can be further reduced in size and size. Therefore, even if the pretensioner 8 is installed on the side surface of the vehicle seat 2, it is possible to more effectively suppress the pretensioner 8 from protruding in the left-right direction of the vehicle, and the occupant M is seated or separated from the vehicle seat 2. At this time, the possibility that the pretensioner 8 becomes an obstacle can be reduced. In this way, it becomes possible to efficiently use the dead space in the vehicle compartment, and the degree of freedom of installation of the pretensioner 8 can be further effectively increased.

Furthermore, when the seat belt pressing member 12a presses the front end portion of the seat belt 4 by guiding the non-retained portion of the front end portion 4c of the seat belt 4 by the seat belt guide roller 18, the front end portion 4c It becomes possible to fold the non-retained portion by the same fold as the folded portion of the front end portion 4c. Thereby, the width W ₁ of the front end portion 4c of the seat belt 4 pressed by the seat belt pressing member 12a can be easily reduced with a simple configuration of only the seat belt guide roller 18.

Further, the guide member 12b guides the seat belt pressing member 12a so as to move along a circular orbit concentric with or substantially concentric with the center of the bending portion 13b of the pipe 13, so that the force transmission member 17 also bends the pipe 13. It becomes possible to guide the inside of the part 13b along this circular orbit. Thereby, the friction between the seatbelt pressing member 12a and the front end portion 4c and the friction between the force transmission member 17 and the inner peripheral surface 13c of the pipe 13 can be suppressed. Therefore, even if the force transmission member 17 is formed relatively long, the force transmission member 17 and the seat belt pressing member 12a can be moved more smoothly. Therefore, the energy of the pressure gas can be used effectively, and the seat belt 4 can be pulled efficiently and quickly tensioned. As a result, occupant restraint by the seat belt 4 can be effectively improved.

6C is a view similar to FIG. 6A showing a second example of the embodiment of the pretensioner of the present invention, and FIG. 6D is a VID-VID line in FIG. 6C. FIG. 6E is a sectional view similar to FIG. 6D, showing a third example of the embodiment of the pretensioner of the present invention.

As shown in FIGS. 6C and 6D, in the pretensioner 8 of the second example, the folded portion of the front end portion 4c of the seat belt 4 is folded in a spiral shape and sewn and held in shape. Yes. In this case, the shape retaining portion region is a region where at least the shape retaining portion abuts against the seat belt guide roller 18 when the seat belt 4 is pulled to a preset maximum pull amount by pressing of the seat belt pressing member 12a. Is set to In the pretensioner 8 of the second example, the width W ₂ of the folded portion of the tip portion 4c becomes substantially one-third of the width of W ₀ of the seat belt 4, it is smaller than the width W ₁ of the first embodiment described above. Therefore, since the thickness of the pretensioner 8 of the second example is smaller than the thickness of the pretensioner 8 of the first example described above, it can be formed even more compactly. Other configurations and other functions and effects of the pretensioner 8 of the second example are the same as those of the first example. Furthermore, as shown in FIG. 6 (E), in the pretensioner 8 of the third example, the folded portion of the front end portion 4c of the seat belt 4 is folded in a serpentine shape and is sewn and held in shape. Other configurations and operational effects of the pretensioner 8 of the third example are the same as those of the second example shown in FIGS. 6C and 6D.

FIG. 7A is an exploded perspective view showing a fourth example of the embodiment of the pretensioner of the present invention, FIG. 7B is an enlarged view of the VIIB portion in FIG. 7A, and FIG. FIG. 8 (B) is a perspective view seen from the side opposite to the mounting side of the fourth example pretensioner, and FIG. 9 (A) is a fourth example pretensioner. FIG. 9B is a left side view of the pretensioner of the fourth example. The same components as those of the first example pretensioner described above are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIGS. 7A and 7B, FIGS. 8A and 8B, and FIGS. 9A and 9B, the pretensioner 8 of the fourth example is the same as the above-described examples. Is provided with a substantially flat cylindrical container-like frame 9. In this case, the frame 9 of the fourth example is substantially fan-shaped when viewed in the same direction as the third frame member 9e formed in an approximately L shape when viewed in the same direction as the width direction of the seat belt 4. And a fourth frame member 9f formed.

The third frame member 9e is formed in a substantially U-shaped cross section by left and right side walls 9g, 9h and a peripheral wall 9i connecting them. A first insertion hole 9j through which the support shaft 10 and the seat belt connected member 11 are inserted, a second insertion hole 9k through which the attachment bolt 21 is inserted, and a coupling bolt 22 are inserted into the left and right side walls 9g and 9h. The third insertion hole 9m is formed (in FIG. 7A, the first insertion hole 9j, the second insertion hole 9k, and the third insertion hole m are formed only in the left side wall 9g. Although not shown, the right side wall 9h is also provided to face each hole of the left side wall 9g). A part of the inner peripheral surface of the peripheral wall 9i is an arcuate pipe support portion on which the pipe 13 is fixedly supported.

The fourth frame member 9f is formed in a substantially U-shaped cross section by left and right side walls 9n, 9o and a peripheral wall 9p connecting them. Fourth insertion holes 9q and 9r through which the support shaft 10 and the seatbelt connected member 11 are inserted, and a shaft-shaped seatbelt guide member 23 are inserted into the regions of the fans of the left and right side walls 9n and 9o. A fifth insertion hole 9s, a sixth insertion hole 9t through which the coupling bolt 22 is inserted, and a seventh insertion hole 9u through which the roller support shaft 18b that rotatably supports the seat belt guide roller 18a is inserted. (Note that in FIG. 7A, the fifth insertion hole 9s and the sixth insertion hole t are not shown only in the left side wall 9n, but the right side wall 9o and the left side wall 9n are also provided in each hole. It is provided oppositely.) A part of the inner peripheral side of the peripheral wall 9p is an arc-shaped outer peripheral seat belt guide portion 20 as in the first example.

Further, the left and right side walls 9g and 9h of the third frame member 9e have first end pressure support portions 9v at the ends in the vicinity of the seat belt entrance 9d, and left and right side walls of the fourth frame member 9f. Each end in the vicinity of the seat belt entrance 9d at 9n, 9o is a second clamping support portion 9w. In a state where the third frame member 9e and the fourth frame member 9f are coupled, the first and second clamping support portions 9v and 9w are opposed to each other. The distance between the left and right side walls 9g, 9h of the third frame member 9e is such that the distance in the area other than the area of the first clamping pressure support portion 9v is greater than the distance in the area of the first clamping pressure support portion 9v. The fixed amount is set large. Further, the distance between the left and right side walls 9n, 9o of the fourth frame member 9f is substantially equal to the left and right side walls 9g, 9h of the third frame member 9e over the entire area of the left and right side walls 9n, 9o of the fourth frame member 9f. It is set to be the same as or substantially the same as the interval in the region of the first clamping support portion 9v. When the third frame member 9e and the fourth frame member 9f are coupled, the predetermined area including the main areas of the fans on the left and right side walls 9n, 9o of the fourth frame member 9f is the third area. The left and right side walls 9g and 9h of the frame member 9e are fitted between regions other than the region of the first clamping support portion 9v.

The pipe 13 is supported by the left and right side walls 9g, 9h and the peripheral wall 9i of the third frame member 9e. An arcuate seat belt pressing member 12 a of the seat belt tensioning member 12 is disposed in the bending portion 13 b of the pipe 13 so as to be movable along the bending portion 13 b of the pipe 13. In that case, in the first example described above, the seat belt pressing member 12a and the arc-shaped force transmission member 17 are constituted by two different members, but in this fourth example, the seat belt pressing member 12a and the force transmission member. 17 is integrally formed of a single member. In other words, in the fourth example, the force transmission member 17 is omitted, and only one arc-shaped seat belt pressing member 12a is provided. Therefore, one end of the seat belt pressing member 12a of the fourth example is directly pressed by the pressing force of the piston 15. Further, in the pretensioner 8 of the fourth example, the guide member 12b of the first example for guiding the seat belt pressing member 12a is not provided.

The end of the seat belt pressing member 12a on the piston 15 side is formed in a circular cross section, and the vicinity of the end of the seat belt pressing member 12a opposite to the piston 15 side is formed in a rectangular cross section. The cross-sectional shape of the seat belt pressing member 12a is continuously changed from a circular cross-sectional shape to a rectangular cross-sectional shape. Further, the end of the seat belt pressing member 12a opposite to the piston 15 side is formed in a partial columnar shape and serves as a seat belt pressing portion 12f capable of pressing the seat belt 4. In that case, the length of the seat belt pressing portion 12f in the seat belt width direction is set to be substantially equal to the width of the seat belt 4, and the end of the seat belt pressing member 12a having a rectangular cross section on the opposite side to the piston 15 side. The seat belt pressing portion 12f and the end portion having a rectangular cross section of the seat belt pressing member 12a are formed in a T-shape. Further, the partial circular arc surface of the seat belt pressing portion 12 f can be brought into contact with the front end portion 4 c of the seat belt 4.

As shown in FIGS. 7 (A), 10 (A), 10 (B), and 11 (A), 11 (B), the vicinity of the first clamping support portion 9v in the third frame member 9e ( That is, the lock member 16 is provided at the position of the seat belt entrance 9d in the third frame member 9e. Therefore, in the pretensioner 8 of the fourth example, the lock member 16 is not provided between the seat belt pressing member 12a and the piston 15 as in the first example. The lock member 16 of the fourth example includes a second lock body 16e that is cylindrical and curved in an arc shape, a lock roller 16f, a lock spring 16g, and a spring support retainer portion 16h. .

The second lock body 16e has a protrusion 16j having an inclined surface 16i on the inner peripheral surface. The second lock main body 16e is externally fitted to the distal end (the end opposite to the linear portion 13a) of the curved portion 13b of the pipe 13, and the second lock main body 16e is provided on the left and right side walls 9g, 9h of the third frame member 9e. 1 is inserted into the vicinity of the clamping support portion 9v and assembled. In that case, the protrusion 16j of the second lock body 16e is fitted into a concave notch 9x formed in the peripheral wall 9i of the third frame member 9e.

The locking roller 16f is formed with the protrusion 16j of the second lock body 16e in a state where the third frame member 9e on which the pipe 13 is fixedly supported and the second lock body 16e are assembled as described above. A guide 13d having a notch groove formed between the inner side and the arc-shaped seat belt pressing member 12a and facing the inner side of the protruding portion 16j on the pipe 13 is arranged to be able to roll.

The spring support retainer portion 16h is provided on the bracket 24 disposed between the third and fourth frame members 9e and 9f. The locking spring 16g is contracted between the locking roller 16f and the spring support retainer portion 16h, and the locking roller 16f is always urged lightly toward the inclined surface 16i by the urging force of the locking spring 16g. The

In the lock member 16 of the fourth example configured as described above, an arrow is pressed by the pressing force of the piston 15 and the seat belt pressing member 12a presses the front end portion 4c of the seat belt 4 as shown in FIG. When moving in the A direction (counterclockwise in FIG. 11A), the locking roller 16f rolls away from the inclined surface 16i of the ridge 16j by the moving force of the seat belt pressing member 12a. It moves against the urging force of the locking spring 16g in the direction. Thereby, the locking roller 16f hardly presses the seat belt pressing member 12a, and the locking member 16 does not perform the locking action. Therefore, the seat belt pressing member 12a can move smoothly in the pipe 13 without receiving resistance from the locking roller 16f of the locking member 16.

Further, as shown in FIG. 11B, when the seat belt pressing member 12a is about to move in the direction of arrow B (the direction of the piston 15), the locking roller 16f is directed toward the inclined surface 16i of the ridge portion 16j. The lock roller 16f moves and is pressed between the inclined surface 16i and the outer peripheral side surface of the arc-shaped seat belt pressing member 12a. At this time, the wedge force between the inclined surface 16i and the outer peripheral side surface of the seat belt pressing member 12a increases the clamping force of the locking roller 16f, and the locking member 16 performs the locking action of the seat belt pressing member 12a. As a result, the seat belt pressing member 12a is locked in the direction of the arrow B, and cannot move in the pipe 13 in the same direction. In that case, since the locking roller 16f is urged by the urging force of the locking spring 16g and moves effectively, the seat belt pressing member 12a is stably locked by the locking member 16.

7A and 7B, the bracket 24 provided with the spring support retainer portion 16h is further provided with a stopper 25 and a locking claw 26. The stopper 25 is formed to be curved in an arc shape, and has a groove 25 a formed in the same direction as the width direction of the seat belt 4 at a substantially central position in the arc direction of the curved portion. Further, the locking claw 26 can be locked to a locked portion 9y provided on the third frame member 9e, and the locking claw 26 is engaged with the locked portion as shown in FIGS. 10 (A) and 10 (B). The bracket 24 is supported by the third frame member 9e by being locked to the stop portion 9y. The bracket 24 is formed by integrating the spring support retainer portion 16h, the stopper 25, and the locking claw 26 with resin.

When the pretensioner 8 is in the non-operating state shown in FIG. 10A during normal operation, the seat belt pressing portion 12f of the seat belt pressing member 12a abuts against the curved portion of the stopper 25, so that the seat belt pressing The member 12a is prevented from moving in the direction in which the front end portion 4c of the seat belt 4 is pressed, and is held at the non-operating position shown in FIG. 10B when the pretensioner 8 is in an emergency state, the seat belt pressing member 12a is pressed by the pressing force of the piston 15 so that the stopper 25 is broken and expanded to move. become. By the movement of the seat belt pressing member 12a, the seat belt pressing portion 12f of the seat belt pressing member 12a comes into contact with the front end portion 4c of the seat belt 4. Thereafter, the front end portion 4c of the seat belt 4 is pressed by the seat belt pressing portion 12f and pulled into the frame 9, and the seat belt 4 is tensioned. In that case, since the stopper 25 is easily broken by the groove 25a, the seat belt pressing member 12a moves quickly to tension the seat belt 4.

The assembly of the pretensioner 8 of the fourth example configured as described above will be described. First, the gas generator 14, a biasing member (not shown) for biasing the piston 15, the piston 15, and the seat belt pressing member 12 a are accommodated in the pipe 13, and the second lock body 16 e is fitted into the pipe 13. After being joined, the pipe 13 is fixedly supported on the peripheral wall 9i of the third frame member 9e. Next, the locking roller 16f and the locking spring 16g are accommodated in the second lock body 16e, and then the locking claw 26 of the bracket 24 is locked to the locked portion 9y, so that the bracket 24 is third. It is supported by the frame member 9e.

Meanwhile, the seat belt guide roller 18a is rotatably supported by the fourth frame member 9f by the roller support shaft 18b. In that case, the roller support shaft 18b is inserted into the seventh insertion hole 9u and the seat belt guide roller 18a while the seat belt guide roller 18a is positioned between the left and right side walls 9n, 9o of the fourth frame member 9f. Are attached to the fourth frame member 9f.

Next, as described above, the predetermined area including the main area of the fan on the left and right side walls 9n and 9o of the fourth frame member 9f is inserted between the left and right side walls 9g and 9h of the third frame member 9e. At the same time, the first insertion hole 9j of the third frame member 9e and the fourth insertion holes 9q, 9r of the fourth frame member 9f are aligned. Next, a cylindrical seat belt connected member 11 to which the front end 4a of the seat belt 4 is connected is disposed on the left and right side walls 9n, 9o of the fourth frame member 9f, and the first insertion hole 9j and The support shaft 10 is then inserted into the first insertion hole 9j, the fourth insertion holes 9q, 9r, and the seat belt connected member 11 and assembled to the frame 9 after being aligned with the fourth insertion holes 9q, 9r. . At this time, as shown in FIGS. 8A and 9B, the support shaft 10 protrudes outward from the frame 9. A male screw is formed on the protruding portion of the support shaft 10.

Next, the fourth frame member 9f is rotated relative to the third frame member 9e about the seat belt connected member 11 (that is, the support shaft 10), and the third insertion hole 9m and the sixth frame member 9f are rotated. After the insertion hole 9t is aligned, the coupling bolt 22 is inserted into the third and sixth insertion holes 9m and 9t, whereby the third frame member 9e and the fourth frame member 9f are coupled. Thus, the frame 9 is formed. At this time, the bracket 24 and the flange portion 16k of the second lock body 16e are formed between the first clamping support portion 9v of the third frame member 9e and the second clamping support portion 9w of the fourth frame member 9f. Sandwiched between. As shown in FIGS. 10A and 10B, the bracket 24 is partially sandwiched between the third and fourth frame members 9e and 9f.

Next, the mounting bolt 21 is inserted and assembled into the second insertion hole 9k of the third frame member 9e. At this time, as shown in FIGS. 8A and 9B, the mounting bolt 21 protrudes outward from the frame 9. Further, the seat belt guide member 23 is inserted and assembled into the fifth insertion hole 9s of the fourth frame member 9f. Thus, the pretensioner 8 of the fourth example is assembled. And the pretensioner 8 of this 4th example is assembled | attached to the vehicle seat 2 by fixing to the side surface of the vehicle seat 2 with the external thread of the support shaft 10, and the attachment bolt 21 at two places. By fixing the support shaft 10 and the mounting bolt 21 at two places, when a rotational force is applied to the frame 9, the frame 9 is prevented from rotating. That is, the support shaft 10 and the mounting bolt 21 constitute a pretensioner rotation prevention mechanism that prevents the pretensioner 8 from rotating.

By the way, as shown in FIG. 10A, in the pretensioner 8 of the fourth example, the front end portion 4c of the seatbelt 4 is wound around the seatbelt connected member 11 similarly to the pretensioner 8 of the first example. , tip 4c ₂ of the distal end side of the winding portion 4c ₁ are overlapped from the wound portion 4c ₁ on the front side of the distal end portion 4c. A portion 4c ₃ overlay tip 4c is joined by a suitable bonding means such as stitching or adhesive. In that case, the joining strength of the overlapping portion 4c ₃ of the front end portion 4c (that is, the connection strength of the front end portion 4c of the seat belt 4 to the seat belt connected member 11) is the length of the overlapping portion 4c ₃ of the front end portion 4c. The longer the length L (mm), the larger.

Therefore, in the pretensioner 8 of the fourth example, the center C _{2 of} the first insertion hole 9j (that is, substantially the center of the support shaft 10 and the seat belt connecting member 11) is the center C ₁ of the arc of the curved portion 13b of the pipe 13. In other words, the center C ₁ is decentered by a predetermined amount from the center C ₁ to the opposite side of the seat belt entrance 9 d from the center of the arc 13 of the curved portion 13 b of the pipe 13. Thereby, the overlapping portion 4c ₃ of the tip portion 4c has a length without the tip portion 4c ₂ interfering with other members (in the fourth example shown in FIG. 10A, the spring support retainer portion 16h). It becomes possible to lengthen L (mm) more effectively. Therefore, the bonding strength of the overlapping portion of the tip portion 4c is effectively increased. Further, since the center C ₂ is eccentrically provided in a range not exceeding the pipe 13, the pretensioner 8 is formed in a compact and compact manner like the pretensioner 8 of the first example even if the center C ₂ is eccentric. Is done.

Next, the operation of the pretensioner 8 of the fourth example will be described.
As described above, the pretensioner 8 is in a non-operating state shown in FIG. In this non-actuated state of the pretensioner 8, the seat belt 4 has only a portion necessary for being connected to the seat belt connected member 11 entering the frame 9. Not drawn. The tip portion 4c ₂ of the seat belt 4, the clockwise rotation is prevented in FIG 10 (A) the tip abuts the flange portion 16k of the locking member 16. Further, as in the first example, the piston 15 is lightly urged to the right in FIG. 10A (that is, the direction away from the gas generator 14), and the arc-shaped seat belt pressing member 12a is rotated counterclockwise. Is energized. Therefore, as described above, the seat belt pressing member 12a is prevented from moving in the direction in which the seat belt pressing portion 12f abuts against the stopper 25 and presses the front end portion 4c of the seat belt 4. At this time, the stopper 25 is not broken. As a result, the seat belt pressing member 12a and the piston 15 are held in the non-operating position. Further, the front end portion 4 c of the seat belt 4 is slightly bent in contact with the seat belt guide member 23 and the stopper 25.

In an emergency, the piston 15 is operated by the gas pressure generated by the gas generator 14 as in the first example. Accordingly, as shown in FIG. 10B, the piston 15 directly and strongly presses the seat belt pressing member 12a, so that the seat belt pressing portion 12f of the seat belt pressing member 12a breaks the stopper 25 and expands. As a result, both the piston 15 and the seat belt pressing member 12a are guided by the curved portion 13b of the pipe 13 and rotate (move) counterclockwise (in the direction of arrow A in FIG. 11) along the circular orbit of the curved portion 13b. . At this time, as described above, the lock member 16 does not lock the seat belt pressing member 12a, and the seat belt pressing member 12a rotates smoothly. The seat belt pressing member 12a rotates while the seat belt pressing portion 12f directly contacts the front end portion 4c of the seat belt 4 and presses the front end portion 4c. For this reason, the front end 4c of the seat belt 4 is drawn into the frame 9 while being guided and curved by the seat belt guide roller 18a, the seat belt guide member 23, and the outer side seat belt guide portion 20. In this way, the pretensioner 8 applies tension to the seat belt 4 to tension the seat belt 4 and increases the occupant restraining force by the seat belt 4. Further, although the frame 9 applies a clockwise force in FIG. 10B by the gas pressure, the pretensioner 8 does not rotate by the above-described pretensioner rotation prevention mechanism.

After the operation of the pretensioner 8, the front end 4 c of the seat belt 4 tends to be pulled out from the frame 9 due to the inertia of the occupant. For this reason, the front end 4c tries to turn the seat belt pressing member 12a in the direction of the arrow B shown in FIG. 11B. However, as described above, the lock member 16 locks the seat belt pressing member 12a. The belt pressing member 12a does not rotate in the arrow B direction. This prevents the leading end 4c from being pulled out from the frame 9. Therefore, the occupant restraining force by the seat belt 4 is maintained in an increased state. At this time, the rotation of the seat belt pressing member 12a in the direction of arrow B is locked, so that the frame 9 is applied with a clockwise force in FIG. 10B. The pretensioner 8 does not rotate. Therefore, the occupant restraining force by the seat belt 4 is maintained in an increased state.
Other configurations and other operations of the pretensioner 8 of the fourth example are the same as those of the pretensioner 8 of the first to third examples.

According to the pretensioner 8 of the fourth example, the force transmission member 17 of the pretensioner 8 of the first example is omitted, and only one arc-shaped seat belt pressing member 12a is provided. The pressing member 12a is directly pressed by the piston 15 in an emergency to press the front end portion 4c of the seat belt 4. In the pretensioner 8 of the fourth example, the guide member 12b of the first example is not provided. Therefore, the number of parts can be reduced compared to the first example, the configuration of the pretensioner 8 can be simplified, and the pressing force of the piston 15 can be more effectively transmitted to the seat belt pressing member 12a. It becomes.

Also, a pretensioner rotation prevention mechanism including the support shaft 10 and the mounting bolt 21 is provided. Thereby, even if a rotational force is applied to the pretensioner 8, the rotation of the pretensioner 8 can be prevented. Therefore, the rotation of the pretensioner 8 due to the gas pressure when the pretensioner 8 is operated and the rotation of the pretensioner 8 due to the inertial force of the occupant after the operation of the pretensioner 8 can be prevented. The pretensioner rotation prevention mechanism is not limited to the support shaft 10 and the mounting bolt 21. For example, in the first example, the pretensioner 8 and the vehicle body It can also be configured by other appropriate anti-rotation mechanisms such as a concavo-convex part or a step part provided between and engaging each other.

Further, the center C ₂ of the winding portion 4c ₃ of the seat belt 4 wound around the seat belt connected member 11 is from the center C ₁ of the arc of the curved portion 13b of the pipe 13 to the seat belt entrance 9d with respect to this center C _1. Is eccentric by a predetermined amount on the opposite side. Thereby, it becomes possible to lengthen the length L (mm) of the overlapping portion 4c ₃ of the front end portion 4c of the seat belt 4 more effectively. Therefore, it is possible to increase the bonding strength of the overlapping portion of the tip portion 4c.

Further, a lock member 16 is provided at the position of the seat belt entrance 9 d in the frame 9. As a result, the lock member 16 can be assembled more easily than in the first example.

Further, the seat belt guide member of the seat belt 4 pressed by the seat belt pressing member 12 a and drawn into the frame 9 is constituted by an axial seat belt guide member 23. Thereby, the seat belt guide structure for guiding the seat belt 4 can be simplified.
Other functions and effects of the pretensioner 8 of the fourth example are the same as those of the pretensioner 8 of the first to third examples.

The pretensioner and the seat belt device of the present invention are not limited to the examples of the above-described embodiments of the present invention, and various design changes can be made within the scope of the matters described in the claims. It is.

The pretensioner and the seat belt device of the present invention are suitable for a pretensioner and a vehicle seat belt device that increase the restraining force of the occupant by the seat belt by pulling the seat belt with pressure gas in the initial stage of an emergency such as a vehicle collision. Can be used.

DESCRIPTION OF SYMBOLS 1 ... Seat belt apparatus, 2 ... Vehicle seat, 3 ... Seat belt retractor, 4 ... Seat belt, 4a ... Shoulder belt, 4b ... Wrap belt, 4c ... Tip part, 4c ₁ ... Winding part, 4c ₂ ... Tip part, 4c ₃ ... overlapped portion, 4d ... stitched portion, 5 ... guide anchor, 6 ... tongue, 7 ... buckle, 8 ... pretensioner, 9 ... frame, 9a ... first frame member, 9b ... second frame member, 9d ... Seat belt entrance, 9e ... Third frame member, 9f ... Fourth frame member, 9i ... Peripheral wall, 9p ... Peripheral wall, 9y ... Locked portion, 10 ... Support shaft, 11 ... Seat belt connected member , 12 ... Seat belt tension member, 12a ... Seat belt pressing member, 12b ... Guide member, 12c ... First arm portion, 12d ... Second arm portion, 12e ... Connection portion, 12f ... Seat belt Pressure part, 13 ... Pipe, 13a ... Linear part, 13b ... Curved part, 13c ... Inner peripheral surface, 14 ... Gas generator, 15 ... Piston, 16 ... Lock member, 16a ... First lock body, 16b ... For locking Ball, 16c ... concave portion, 16d ... inclined surface, 16f ... locking roller, 16i ... inclined surface, 16j ... ridge, 17 ... force transmission member, 17a ... protrusion, 18, 18a ... seat belt guide roller, 19 ... Inner peripheral side seat belt guide part, 20 ... Outer peripheral side seat belt guide part, 21 ... Mounting bolt, 22 ... Connection bolt, 23 ... Seat belt guide member, 24 ... Bracket, 25 ... Stopper, 25a ... Groove, 26 ... Locking Claw, C ₂ ... center of the first insertion hole 9j, C ₁ ... center of the arc of the curved portion 13b of the pipe 13, L ... length of the overlapping portion 4c ₃ , M ... occupant

Claims (19)

1. A pipe having at least an arc-shaped curved portion;
   A seat belt pressing member that is provided so as to be movable along a circular orbit of a concentric circle or a substantially concentric circle with the curved portion of the pipe and that tensions the seat belt by pressing the front end portion of the seat belt on the front end side from the lap belt;
   A gas generator that generates gas in an emergency,
   A pretensioner comprising at least a piston that is movably provided in the pipe and that operates with the gas pressure of the gas to generate a pressing force that presses the seat belt pressing member.
2. 2. The seat belt pressing member according to claim 1, wherein at least a part of the seat belt pressing member is formed in an arc shape, and at least a part of the arc-shaped portion is provided so as to be movable in a curved portion of the pipe. Pretensioner.
3. 3. The pretensioner according to claim 1, further comprising a seat belt pressing member stopper that holds the seat belt pressing member in a non-operating state in a normal state and enables the seat belt pressing member to operate in an emergency. .
4. A container-like frame having a seat belt entrance for the pipe and the seat belt pressing member to be disposed and the seat belt entering the interior;
   4. The seat belt according to claim 1, wherein the seat belt pressing member presses a front end portion of the seat belt and pulls the seat belt into an inner space of the frame through the seat belt entrance, thereby tensioning the seat belt. The pretensioner according to claim 1.
5. A seat belt connected member to which the seat belt is connected in an internal space of the frame;
   The pretensioner according to claim 4, wherein the seat belt connected member is provided at a position eccentric from a center of an arc of the curved portion of the pipe.
6. 6. The lock member according to claim 1, further comprising: a lock member that locks at least the seat belt pressing member to move in a direction opposite to a pressing direction with respect to a front end portion of the seat belt when the operation ends. Pretensioner.
7. A lock member that locks at least movement of the seat belt pressing member in a direction opposite to the pressing direction with respect to the front end portion of the seat belt at the end of operation;
   The pretensioner according to claim 4 or 5, wherein the lock member is provided at a position of the seat belt entrance of the frame.
8. The pretensioner according to any one of claims 4, 5, and 7, further comprising a pretensioner rotation prevention mechanism that prevents the pretensioner from rotating.
9. An arc-shaped force transmission member provided at least partially movable in the curved portion of the pipe and capable of pressing the seat belt pressing member;
   The pretensioner according to any one of claims 1 to 8, wherein the seat belt pressing member is pressed through the force transmission member by a pressing force of the piston.
10. The seat belt pressing member presses the front end portion of the seat belt that has entered the internal space from the seat belt entrance, and the front end portion of the seat belt has the front end portion before entering the seat belt entrance. The pretensioner according to any one of claims 1 to 9, wherein the surface of the pretensioner is turned from the left-right direction of the vehicle to the front-rear direction of the vehicle with the pretensioner installed.
11. The pretensioner according to any one of claims 1 to 10, wherein a part of a front end portion of the seat belt pressed by the seat belt pressing member is folded along a longitudinal direction of the seat belt. .
12. The pretensioner according to claim 11, wherein the folded portion of the front end portion of the seat belt is folded in a spiral shape.
13. The pretensioner according to claim 11, wherein the folded portion of the front end portion of the seat belt is folded in a serpentine manner.
14. The folding portion of the front end portion of the seat belt is characterized in that both side edges in the longitudinal direction of the front end portion are folded along the longitudinal direction of the front end portion toward the center in the width direction of the front end portion. Item 12. The pretensioner according to Item 11.
15. The pretensioner according to any one of claims 11 to 14, wherein a folded portion of a front end portion of the seat belt is sewn and held.
16. When the seat belt pressing member presses the front end portion of the seat belt, the front end portion is shaped so that the unfolded portion of the front end portion is folded in the same folding as the folded portion of the front end portion. The pretensioner according to any one of claims 11 to 15, further comprising a seat belt guide member for guiding a non-existing portion.
17. The pretensioner according to any one of claims 1 to 16, further comprising a guide member that guides the seat belt pressing member so that the seat belt pressing member moves along the circular orbit.
18. The pretensioner according to claim 17, wherein the guide member includes an arm portion that guides the seat belt pressing member to move along the circular orbit by rotating.
19. A seat belt to restrain the occupant;
    A seat belt retractor that winds up the seat belt;
    A tongue slidably supported on the seat belt;
    A buckle on which the tongue is releasably locked;
    And at least a pretensioner that pulls the seat belt in an emergency,
    The seat belt device according to any one of claims 1 to 18, wherein the pretensioner is the pretensioner.

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