JP2016088384A - Pretensioner device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pretensioner device which enables a screw part of a cylinder and a screw part of a cylinder base to be threadedly engaged in an easy manner with a simple structure when the pretensioner device is assembled.SOLUTION: A cylinder base 20 has a base screw part 24 in a gas supply port part 23 for supplying a gas. One end part 31 of the cylinder 30 is attached to the base screw part 24 of the cylinder base 20, and the gas is supplied from the gas supply port part 23 to the cylinder 30. The piston is disposed in the cylinder 30 and moved by the gas. The cylinder 30 has: a cylinder screw part 32 which is threadedly engaged with the base screw part 24 of the cylinder base 20; a contraction part 35 which gradually contracts toward a tip of the other end part 34; and a non-circular opening 36 formed at the tip of the other end part 34.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a pretensioner device for pulling a seat belt of a seat belt device.

  In a vehicle seat belt device provided with a pretensioner device, the pretensioner device is activated and the seat belt is pulled by the pretensioner device in an emergency of the vehicle. At that time, the gas generator of the pretensioner device generates gas, and the gas is supplied to the cylinder from the cylinder base holding the gas generator. The gas causes the piston to move in the cylinder and pulls the wire connected to the seat belt. As a result, the slack of the seat belt is removed, and the passenger wearing the seat belt is restrained by the seat.

By the way, a cylindrical member is used for the cylinder of the pretensioner device mainly from the viewpoint of cost and strength (see Patent Document 1).
In the conventional pretensioner device described in Patent Document 1, when the pretensioner device is assembled, the screw portion of the cylinder is screwed into the screw portion of the cylinder base (base cartridge). The cylinder is attached to the cylinder base by screwing the threaded portion.

  Further, when assembling the pretensioner device, generally, the cylinder is rotated and attached to the cylinder base by a chuck that chucks the outer periphery of the cylinder. However, in a cylindrical cylinder, the chuck is easily slipped on the outer periphery of the cylinder, and it takes time to screw the cylinder screw portion and the cylinder base screw portion. In addition, when the anti-loosening agent is applied to the thread portion of the cylinder, a stronger force is required for the rotation of the cylinder. For this reason, it is necessary to strongly chuck the outer periphery of the cylinder without crushing the cylinder with the chuck, and the burden of the work of screwing the screw portion increases.

JP 2011-63178 A

  The present invention has been made in view of the above-described conventional problems, and the purpose thereof is to easily screw the cylinder screw portion and the cylinder base screw portion into a screw thread when the pretensioner device is assembled. The cylinder is securely attached to the cylinder base.

  The present invention is a pretensioner device for pulling a seat belt of a seat belt device. The pretensioner device includes a gas generator, a cylinder base that holds the gas generator and has a base screw portion in a gas supply port portion that supplies gas generated by the gas generator, and one end portion of the cylinder base base screw portion. A cylindrical cylinder that is attached and supplied with gas from a gas supply port, and a piston that is arranged in the cylinder and moves from one end side to the other end side of the cylinder by the gas supplied into the cylinder And a tension cable fixed to the piston and pulling the seat belt by the movement of the piston. A cylinder screw portion formed at one end and screwed into a base screw portion of the cylinder base, a reduction portion formed at the other end and gradually shrinking toward the tip of the other end, and a tip of the other end A non-circular opening.

  According to the present invention, when assembling the pretensioner device, the cylinder can be securely attached to the cylinder base by easily screwing the screw portion of the cylinder and the screw portion of the cylinder base with a simple structure.

It is a side view which shows the seatbelt apparatus provided with the pretensioner apparatus of this embodiment. It is a side view of the pretensioner device of this embodiment. It is sectional drawing of the pretensioner apparatus cut | disconnected by the VV line | wire of FIG. It is a perspective view which shows the pretensioner apparatus decomposed | disassembled. It is a figure for demonstrating operation | movement of the pretensioner apparatus of this embodiment. It is a figure for demonstrating operation | movement of the pretensioner apparatus of this embodiment. It is a perspective view which shows the cylinder base and cylinder of a pretensioner apparatus. It is a perspective view which shows the cylinder base and cylinder after attachment. It is a figure which shows the formation procedure of the cylinder of this embodiment. It is a figure which shows the formation procedure of the cylinder of this embodiment. It is a figure which shows the formation procedure of the cylinder of this embodiment. It is a figure which shows the formation procedure of the cylinder of this embodiment. It is a figure which shows the formation procedure of the cylinder of this embodiment. It is a side view which shows the pretensioner apparatus which pulls a buckle.

An embodiment of a pretensioner device of the present invention will be described with reference to the drawings.
The pretensioner device of this embodiment is used in a vehicle seat belt device, and pulls the seat belt of the seat belt device in the event of a vehicle emergency.

FIG. 1 is a side view showing a seat belt device 1 including a pretensioner device 10 according to the present embodiment, and shows the seat belt device 1 mounted on a vehicle.
As shown in the figure, the occupant 2 sits on the seat 3 of the vehicle and wears the seat belt 4 of the seat belt device 1. The seat 3 is, for example, a driver seat, a passenger seat, or a rear seat, and includes a seat cushion 3A and a seat back 3B.

  The seat belt device 1 includes a pretensioner device 10, a seat belt 4, a seat belt guide 5, a retractor device 6, a tongue 7, and a buckle 8. The pretensioner device 10 is disposed on the side of the seat 3 and is fixed to a lower portion (for example, a floor) of the vehicle. The seat belt 4 is a long belt-like member (webbing) and is passed through a seat belt guide 5 fixed to the upper part of the vehicle.

  One end of the seat belt 4 is attached to the pretensioner device 10, and the other end of the seat belt 4 is attached to the retractor device 6. The retractor device 6 is a winding device that winds the seat belt 4 around a winding drum, and is fixed to the vehicle on the side of the seat 3. The tongue 7 is attached to the seat belt 4 and moves in the longitudinal direction of the seat belt 4. The buckle 8 has a lock mechanism for locking the tongue 7 and is fixed to the vehicle on the side of the seat 3. The tongue 7 is locked to the buckle 8 by inserting the tongue 7 into the buckle 8.

  When the seat belt 4 is mounted, the occupant 2 pulls out the seat belt 4 from the retractor device 6 and locks the tongue 7 to the buckle 8. In this state, the seat belt 4 includes a shoulder belt 4A between the seat belt guide 5 and the tongue 7 and a lap belt 4B between the tongue 7 and the pretensioner device 10. When removing the seat belt 4, the occupant 2 releases the lock of the tongue 7 by the buckle 8 and winds the seat belt 4 around the retractor device 6.

  In the event of a vehicle emergency, the retractor device 6 stops pulling out the seat belt 4 attached to the occupant 2. In addition, the pretensioner device 10 operates when an operation signal is received from the instruction unit of the vehicle. The instruction unit has various detection sensors (impact detection sensor, deceleration detection sensor, etc.) provided in the vehicle, and outputs an operation signal to the pretensioner device 10 based on the detection result of the detection sensor. Along with the operation, the pretensioner device 10 pulls one end of the seat belt 4 to remove the slack of the seat belt 4. The occupant 2 is protected by being restrained by the seat belt 4.

FIG. 2 is a side view of the pretensioner device 10 of the present embodiment, showing the pretensioner device 10 viewed from the opposite side of FIG. 3 is a cross-sectional view of the pretensioner device 10 cut along the line VV in FIG. 2, and FIG. 4 is a perspective view showing the pretensioner device 10 disassembled.
As illustrated, the pretensioner device 10 includes a gas generator 11, a cylinder base 20, a cylindrical cylinder 30 attached to the cylinder base 20, a piston 40, a wire 50 fixed to the piston 40, and a guide. Means 60 are provided. The gas generator 11 generates gas in an emergency of the vehicle and supplies the gas into the cylinder 30 through the cylinder base 20. The cylinder base 20 and the cylinder 30 are each formed in a predetermined shape from metal.

  The cylinder base 20 includes a holding portion 21 that holds the gas generator 11, a cylindrical gas introduction portion 22, a gas supply port portion 23 to which the cylinder 30 is attached, and a screw portion formed in the gas supply port portion 23 ( 24). The gas generator 11 is accommodated in a cylindrical holding part 21 and fixed to the holding part 21 by a cap 25. The cylinder base 20 holds the gas generator 11 in the holding portion 21, and the gas generator 11 generates gas toward the inside of the gas introduction portion 22. The seal member 26 is fixed to one end of the gas introduction part 22 by the guide means 60 to seal the opening at one end of the gas introduction part 22.

  The gas supply port portion 23 of the cylinder base 20 is a part of the gas introduction portion 22 (a portion including the opening at the other end of the gas introduction portion 22), and supplies the gas generated by the gas generator 11 to the cylinder 30. The cylinder base 20 has a base screw portion 24 at the gas supply port portion 23. The base screw portion 24 is a female screw portion formed on the inner periphery of the gas supply port portion 23. Corresponding to the base screw portion 24 on the cylinder base 20 side, the cylinder 30 has a screw portion (referred to as a cylinder screw portion) 32 formed at one end portion 31. The cylinder screw portion 32 on the cylinder 30 side is a male screw portion formed on the outer periphery of the one end portion 31 of the cylinder 30 and is screwed into the base screw portion 24 of the cylinder base 20. One end 31 of the cylinder 30 is attached to the gas supply port 23 of the cylinder base 20 by screwing the base screw portion 24 and the cylinder screw portion 32, and the cylinder 30 is connected to the cylinder base 20.

  When the gas generator 11 generates gas, the gas is introduced into the gas introduction part 22 of the cylinder base 20 and supplied from the gas supply port part 23 to the internal space 33 of the cylinder 30. Further, the gas is supplied from the one end portion 31 of the cylinder 30 toward the other end portion 34 in the internal space 33 and flows in the central axis direction of the cylinder 30. The central axis of the cylinder 30 is a straight line (axis) passing through the center of the cylinder 30 in the radial direction. The cross-sectional shape orthogonal to the central axis of the cylinder 30 is a circular shape.

  The piston 40 is disposed in the cylinder 30 and moves from the one end portion 31 side to the other end portion 34 side of the cylinder 30 by the gas supplied from the gas supply port portion 23 into the cylinder 30. The piston 40 is a cylindrical moving body and has a tapered portion 41 formed on the outer periphery. Two elastic rings 42 and 43 are attached to the outer periphery of the piston 40, and a plurality of spheres 44 are arranged in a tapered portion 41 located between the two elastic rings 42 and 43. The plurality of spheres 44 are accommodated in a space between the tapered portion 41 and the cylinder 30 and are disposed so as to surround the tapered portion 41.

  The piston 40 is disposed on the one end 31 side of the cylinder 30 and moves in the direction of the central axis of the cylinder 30 in the internal space 33 by the pressure of gas when the pretensioner device 10 is operated. At this time, the plurality of spheres 44 are positioned at the thinnest portion of the tapered portion 41 and do not hinder the movement of the piston 40. The piston 40 moves to the other end 34 of the cylinder 30 and stops at the other end 34. On the other hand, when the piston 40 moves toward the one end portion 31 side of the cylinder 30, the plurality of spheres 44 are sandwiched between the tapered portion 41 of the piston 40 and the inner peripheral surface of the cylinder 30. Thereby, movement of piston 40 is prevented and piston 40 stops.

  The wire 50 is a connecting member that connects the seat belt 4 and the piston 40, and is a tension member (here, a tension cable) that pulls the seat belt 4 by the movement of the piston 40. One end of the wire 50 is inserted into the piston 40 and fixed to the piston 40 by caulking of the piston 40. Further, a ring 51 is provided in the other end of the ring of the wire 50 and is attached to the other end of the wire 50 by a sleeve 52 fixed to the wire 50. The seat belt 4 is attached to the other end portion of the wire 50 through the ring 51.

  The wire 50 is covered with a cylindrical protective member 53 in the gas introduction part 22 of the cylinder base 20. The protection member 53 is attached to the gas introduction part 22 and protects the wire 50 from the gas generated by the gas generator 11. When the pretensioner device 10 is operated, the wire 50 is pulled by the piston 40 moving in the cylinder 30 and pulled into the cylinder 30. Along with this, the wire 50 pulls the seat belt 4 toward the pretensioner device 10.

  The guide means 60 includes a support member 61, a screw 62 for attaching the support member 61 to the cylinder base 20, a disk guide 63 attached to the support member 61, and a stopper 64 attached to the support member 61. The wire 50 passes through the guide hole 61 </ b> A of the support member 61 and the guide hole 64 </ b> A of the stopper 64 and is bent by the disk guide 63. During the operation of the pretensioner device 10, the guide means 60 guides the wire 50 through the guide holes 61 </ b> A and 64 </ b> A and the disk guide 63.

5 and 6 are diagrams for explaining the operation of the pretensioner device 10 of the present embodiment, and a part of the pretensioner device 10 is shown in a cross-sectional view similar to FIG. 5 and 6 show the seat belt 4, the wire 50, and the guide means 60 in a side view.
When the pretensioner device 10 operates (see FIG. 5), the gas generator 11 generates gas, and the piston 40 moves to the other end 34 of the cylinder 30 by the gas (see FIG. 6). At the same time, the wire 50 is pulled by the piston 40 to pull the seat belt 4.

Here, in the pretensioner device 10 of the present embodiment, the cylinder 30 is attached to the cylinder base 20 with an attachment tool without chucking the outer periphery of the cylinder 30 with a chuck.
FIG. 7 is a perspective view showing the cylinder base 20 and the cylinder 30 of the pretensioner device 10 and also shows the attachment tool 9. Further, FIG. 7 shows the cylinder base 20 and the cylinder 30 before being mounted by omitting the components of the pretensioner device 10 other than the cylinder base 20 and the cylinder 30. FIG. 8 is a perspective view showing the cylinder base 20 and the cylinder 30 after being attached by the attachment tool 9.

  As shown in the figure, the cylinder 30 includes a cylinder screw portion 32 formed at one end portion 31, a reduction portion 35 formed at the other end portion 34, and a non-circular opening 36 formed at the tip of the other end portion 34. Have The reducing portion 35 is a bending portion obtained by bending the other end portion 34 of the cylinder 30 inward in the radial direction, and gradually reduces toward the tip of the other end portion 34. The non-circular opening 36 of the cylinder 30 is formed at the most contracted tip of the reducing portion 35 and is used for attaching the cylinder 30 to the cylinder base 20. Further, the opening 36 is a fitting port that fits into the insertion portion 9 </ b> A of the attachment tool 9, and is formed at a position including the central axis of the cylinder 30 at the tip of the other end portion 34.

  The insertion portion 9 </ b> A of the attachment tool 9 is a fitting portion that fits into the non-circular opening 36 of the cylinder 30, and is formed in a non-circular cross-sectional shape corresponding to the opening 36. The insertion portion 9 </ b> A of the attachment tool 9 is inserted into the opening 36 and is fitted into the opening 36. Thereby, the attachment tool 9 is connected to the cylinder 30 so as not to be relatively rotatable. In this state, the cylinder screw portion 32 of the cylinder 30 is brought into contact with the base screw portion 24 of the cylinder base 20. Subsequently, the cylinder 30 is rotated by the attachment tool 9 while the cylinder base 20 is stopped. Alternatively, the cylinder base 20 is rotated with the mounting tool 9 holding the cylinder 30 so as not to rotate. In this manner, the cylinder 30 is rotated relative to the cylinder base 20 by the mounting tool 9, the base screw portion 24 and the cylinder screw portion 32 are screwed together, and the cylinder 30 is attached to the cylinder base 20 (see FIG. 8).

  FIG. 9 to FIG. 13 are diagrams showing a molding procedure of the cylinder 30 of the present embodiment, and show the cylinder 30 that is sequentially molded by the first molding device 70 and the second molding device 75. Specifically, FIG. 9 is a cross-sectional view showing the first molding device 70, and FIG. 10 is a diagram showing the cylinder 30 molded by the first molding device 70. 10A is a side view of the cylinder 30 corresponding to FIG. 9, and FIG. 10B is a front view of the cylinder 30 as viewed from the direction of the arrow X1 in FIG. 10A.

  As illustrated, the first molding device 70 (see FIG. 9) includes a pair of fixing members 71 that fix a circular tube 80 that is a material of the cylinder 30 and a mold that molds one end 81 of the circular tube 80. 72. In a state where the circular tube 80 is sandwiched between the pair of fixing members 71, the end portion 81 of the circular tube 80 is located outside the pair of fixing members 71. The mold 72 has a hemispherical recess 73 and a cylindrical protrusion 74 formed at the center of the recess 73.

  The first molding device 70 presses the mold 72 against the end portion 81 of the circular tube 80 one or more times, and molds the end portion 81 of the circular tube 80 with the mold 72. At that time, the end portion 81 of the circular tube 80 enters the concave portion 73 of the mold 72 and deforms corresponding to the shape of the curved inner surface (concave surface) of the concave portion 73. Further, the protrusion 74 of the mold 72 enters the opening 82 of the end portion 81. The opening 82 of the end 81 is reduced inward in the radial direction, is in close contact with the outer surface of the protrusion 74, and is formed into a shape corresponding to the outer surface shape of the protrusion 74 (see FIG. 10).

  The end portion 81 of the circular tube 80 is formed into a shape that gradually decreases inward in the radial direction toward the tip by the concave portion 73 of the mold 72. Further, the opening 82 of the end portion 81 is formed into a circular shape by the protrusion 74 of the mold 72. After molding by the mold 72, the mold 72 is separated from the end portion 81 of the circular tube 80, and the circular tube 80 is detached from the pair of fixing members 71. Subsequently, the end 81 of the circular tube 80 is formed by the second forming device 75.

  FIG. 11A is a cross-sectional view showing the second molding device 75, and FIG. 11B is a perspective view showing a part of the second molding device 75. FIG. 12 is a cross-sectional view showing the second molding device 75 at the completion of molding, and FIG. 13 is a diagram showing the cylinder 30 molded by the second molding device 75. 13A is a side view of the cylinder 30 corresponding to FIG. 12, and FIG. 13B is a front view of the cylinder 30 as viewed from the direction of the arrow X2 in FIG. 13A.

  The second molding device 75 (see FIG. 11A) includes a holding member 76 that holds the circular tube 80, a molding surface 76B that is formed in the holding hole 76A of the holding member 76, a rod-shaped insertion member 77, and an insertion member. 77 has a forming part 78 formed at the tip of 77. The forming surface 76B of the holding member 76 is a curved concave surface formed at the bottom of the holding hole 76A, and forms the end portion 81 of the circular tube 80. The circular tube 80 is held in the holding hole 76 </ b> A of the holding member 76 in a state where the end portion 81 of the circular tube 80 faces the molding surface 76 </ b> B. Since the space in the molding surface 76B is narrower than the end portion 81 of the circular tube 80, only a part of the end portion 81 is located in the space in the molding surface 76B, and there is a gap between the end portion 81 and the molding surface 76B. It is formed. In this state, the insertion member 77 is inserted into the circular tube 80, and the molding portion 78 of the insertion member 77 is inserted into the opening 82 of the end portion 81 (see FIG. 12).

  The second molding device 75 presses the end 81 of the circular tube 80 against the molding surface 76B of the holding member 76 with the insertion member 77, and molds the end 81 of the circular tube 80 with the molding surface 76B. The end portion 81 of the circular tube 80 is deformed corresponding to the molding surface 76B, and further contracts radially inward. At the same time, the opening 82 of the end portion 81 is contracted radially inward, is brought into close contact with the outer surface of the molding portion 78, and is molded into a predetermined shape corresponding to the outer surface shape of the molding portion 78.

  The forming portion 78 is a protrusion having a non-circular cross-sectional shape (here, oval shape) corresponding to the opening 36 of the cylinder 30 (see FIG. 11B), and penetrates the opening 82 of the end portion 81. The opening 82 of the end portion 81 is formed into a non-circular shape by the forming portion 78 (see FIG. 13). Thereafter, the insertion member 77 is removed from the circular tube 80 and the circular tube 80 is removed from the holding member 76. When burrs are generated outside the circular tube 80, the burrs are removed.

  The end portion 81 of the circular tube 80 is the other end portion 34 of the cylinder 30, and the opening 82 of the end portion 81 is the opening 36 of the cylinder 30. The first molding device 70 and the second molding device 75 form a reduced portion 35 at the other end 34 of the cylinder 30 and form a non-circular opening 36 at the tip of the other end 34. Here, the reducing portion 35 of the cylinder 30 is formed in a hemispherical shape at the other end portion 34 of the cylinder 30, and decreases toward the inner side in the radial direction of the cylinder 30 toward the tip of the other end portion 34. The opening 36 of the cylinder 30 is formed in a long hole shape.

  As described above, when assembling the pretensioner device 10 of the present embodiment, the cylinder 30 is easily and reliably rotated relative to the cylinder base 20 using the non-circular opening 36 of the cylinder 30. Can do. Accordingly, the cylinder 30 can be securely attached to the cylinder base 20 by simply screwing the cylinder screw portion 32 of the cylinder 30 and the base screw portion 24 of the cylinder base 20 with a simple structure. The force for rotating the cylinder 30 can be made stronger than before.

  The cylinder screw portion 32 of the cylinder 30 may be formed on the inner periphery of the one end portion 31 of the cylinder 30, and the base screw portion 24 of the cylinder base 20 may be formed on the outer periphery of the gas supply port portion 23. In this case, the cylinder screw portion 32 of the cylinder 30 is a female screw portion, and the base screw portion 24 of the cylinder base 20 is a male screw portion. Similarly to the above, the cylinder 30 is attached to the cylinder base 20 by screwing the base screw portion 24 and the cylinder screw portion 32 together.

  The opening 36 of the cylinder 30 may be a non-circular opening other than the long hole shape, and is formed in, for example, a polygonal shape (triangular shape, quadrangular shape, hexagonal shape, etc.), an elliptical shape, a cross shape, or a slit shape. May be. The attachment tool 9 is formed in a shape that fits into each shape of the opening 36 and is inserted into the opening 36. Further, the opening 36 of the cylinder 30 may be formed so as not to include the central axis of the cylinder 30 at the tip of the other end 34 of the cylinder 30. However, if the opening 36 of the cylinder 30 is formed at a position including the central axis of the cylinder 30, the cylinder 30 can be relatively rotated relative to the cylinder base 20.

  In the example described above (see FIG. 1), the pretensioner device 10 is attached to one end portion of the seat belt 4 and pulls one end portion of the seat belt 4. On the other hand, the pretensioner device 10 may be attached to the buckle 8. In this case, the pretensioner device 10 pulls the seat belt 4 by pulling the buckle 8.

FIG. 14 is a side view showing the pretensioner device 10 that pulls the buckle 8.
Here, as illustrated, one end of the seat belt 4 is fixed to the vehicle, and the pretensioner device 10 is attached to the buckle 8. The buckle 8 is connected to the wire 50 of the pretensioner device 10. In the event of a vehicle emergency, the pretensioner device 10 pulls the buckle 8 and the seat belt 4 with the wire 50 and removes the slack of the seat belt 4.

  Thus, the seat belt 4 may be pulled directly by the pretensioner device 10, or the seat belt 4 may be pulled indirectly. Alternatively, the seat belt 4 may be pulled by rotating the winding drum of the retractor device 6 by the wire 50 of the pretensioner device 10.

  DESCRIPTION OF SYMBOLS 1 ... Seat belt device, 2 ... Crew, 3 ... Seat, 4 ... Seat belt, 5 ... Seat belt guide, 6 ... Retractor device, 7 ... Tongue, 8 ··· Buckle, 9 ··· Mounting tool, 10 ··· Pretensioner device, 11 ··· Gas generator, 20 ··· Cylinder base, 21 ··· Holding portion, and 22 ··· Gas introducing portion, 23 ... Gas supply port, 24 ... Base screw part, 25 ... Cap, 26 ... Seal member, 30 ... Cylinder, 31 ... One end part, 32 ... Cylinder screw part, 33 ... Internal space, 34 ... other end, 35 ... reduced part, 36 ... opening, 40 ... piston, 41 ... tapered part, 42 ... elastic ring, 43 ... -Elastic ring, 44 ... sphere, 50 ... wire, 51 ... ring, 52 ..Sleeve 53 ... Protective member 60 ... Guide means 61 ... Support member 62 ... Screw 63 ... Disk guide 64 ... Stopper 70 ... First Molding device, 71 ... fixing member, 72 ... mold, 73 ... recess, 74 ... projection, 75 ... second molding device, 76 ... holding member, 77 ... insertion Member, 78 ... molding part, 80 ... circular pipe, 81 ... end part, 82 ... opening.

Claims (2)

A pretensioner device for pulling a seat belt of a seat belt device,
A gas generator;
A cylinder base having a base screw portion in a gas supply port portion for holding a gas generator and supplying gas generated by the gas generator;
A cylindrical cylinder, one end of which is attached to a base screw portion of a cylinder base, and gas is supplied from a gas supply port;
A piston disposed in the cylinder and moving from one end side of the cylinder to the other end side by a gas supplied into the cylinder;
A tension line fixed to the piston and pulling the seat belt by the movement of the piston,
A cylinder screw portion formed at one end and screwed into a base screw portion of the cylinder base, a reduction portion formed at the other end and gradually shrinking toward the tip of the other end, and a tip of the other end And a non-circular opening formed in the pretensioner device. The pretensioner device according to claim 1,
A pretensioner device in which a non-circular opening of a cylinder is formed at a position including the central axis of the cylinder at the tip of the other end.

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