JPH05254391A - Seat belt retractor - Google Patents

Abstract

PURPOSE:To further improve constraining performance for occupants and to strengthen safety by surely preventing drawing-out of a belt after winding of the seat belt with a pretentioner. CONSTITUTION:A seat belt retractor is provided with a pretentioner 5 for winding sag of a seat belt 4 by operating a gas generator 7 based on a detection action of a collision sensor 6, moving a piston 9 in a cylinder part 8 by the generated gas pressure and hauling a wire 10 so as to rotate a spool 3, and a clamp mechanism 11 for locking movement in the drawing-out direction by holding the seat belt 4 with a fixed clamp 12 and a movable clamp 13. A cam part 20 which is projected on the spool and can be moved with it, and a projection part 13f which is projected on the side of a free end 13e of the movable clamp 13 to move a locking face 12a of the fixed clamp 12 so that it can be pressed with the cam part are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat belt retractor used in a vehicle such as an automobile, and more particularly, to instantly wind up the slack of the seat belt caused by the occupant's clothes or the like when the vehicle collides, thereby improving the occupant restraint performance. The present invention relates to a seat belt retractor equipped with a pretensioner.

[0002]

2. Description of the Related Art As a technique of this kind, for example, FIG. 5 (for example, 1988 edition BMW REPAIR MANUA) is used.
As shown in the L 5 series and 7 series), a pretensioner 5 is attached to the housing 2 of the seatbelt retractor body 1. The pretensioner 5 is ignited on the basis of the detection action of the collision sensor 6 to generate an inert gas, and a cylinder part for receiving the generated gas pressure in the gas generator 7 and operating the piston 9. 8 and piston 9
And a wire 10 that is connected to one end 10a and is pulled by the operation of the piston 9 to rotate the spool 3 in the winding direction of the seat belt 4.

The housing 2 has a clamp mechanism 1
1 is provided to prevent the seat belt 4 from being pulled out due to the tightening of the seat belt 4 on the spool 3 due to the inertial movement of the occupant during a collision. The clamp mechanism 11 includes a fixed clamp 12 having a corrugated locking surface 12 a fixed to the housing 2, and a movable clamp 13 pivotally supported by the housing 2. The movable clamp 13 includes a first pin 13a provided on the fixed clamp 12 side of the housing 2 and the first pin 13a.
A bracket 13b, one end of which is rotatably supported by a pin 13a, and an arc-shaped elongated hole 2a, which is rotatably supported by the other end of the bracket 13b and is formed in the housing 2, around the pin 13a The movable second pin 13c
A roller 13d that is axially supported by the second pin 13c and can be pressed against the locking surface 12a of the fixed clamp 12; and a roller 13d that is stretched between the second pin 13c and the housing 2 to fix the roller 13d. And a helper spring 14 biased in a direction away from the locking surface 12a.

Therefore, the seat belt 4 normally wound around the spool 3 is seated by hanging a roller 13d of a movable clamp 13 held by a helper spring 14 at a position with a gap between the seat belt 4 and the fixed clamp 12. It is located outside the belt retractor body 1.

When an automobile collides with the occupant wearing the seatbelt 4, the pretensioner 5 completes the winding of the seatbelt 4 and the seatbelt 4 of the spool 3 by an emergency locking mechanism (not shown). When the seat belt 4 is pulled and pulled out by the inertial movement of the occupant after the rotation in the pull-out direction is locked, the pulling force of the seat belt 4 causes the roller 13d of the movable clamp 13 to resist the spring force of the helper spring 14. Then, the fixed clamp 12 is pushed toward the fixed clamp 12 side.
The seat belt 4 is squeezed by the locking surface 12a of the seat and the roller 13d of the movable clamp 13 to lock the movement of the seat belt 4 in the pull-out direction to avoid the tightening of the seat belt 4 on the spool 3. The seat belt 4 is prevented from being pulled out.

[0006]

However, even if the slack of the seat belt 4 is instantly taken up by the pretensioner 5 at the time of a collision, the clamp mechanism 11 pulls out the seat belt 4 as described above. Since the structure is such that the clamp operation is performed using the action, while the clamp mechanism 11 is operated, the seat belt 4 has a length of 20 to 30 m.
The effect of providing the pretensioner 5 tends to be weakened by pulling out by about m.

Therefore, according to the present invention, after the completion of winding of the seat belt by the pretensioner, the seat belt can be reliably prevented from being pulled out, the occupant restraint performance can be further improved, and the safety can be further enhanced. It is intended to provide a retractor.

[0008]

As a seat belt retractor of the present invention, a gas generator is operated based on the detection action of a collision sensor, and the piston in the cylinder portion is moved by the gas pressure generated by the gas generator, It is equipped with a pretensioner that winds the slack of the seat belt by rotating the spool by pulling the wire that has one end connected to the piston, and presses the movable clamp against the fixed clamp to In a structure including a clamp mechanism that clamps the seat belt by means of, and locks the movement of the seat belt in the pull-out direction, a cam portion protruding from the spool and movable therewith, and a free end portion side of the movable clamp. And the cam portion of the spool can press the locking surface of the fixed clamp. Characterized by providing a protrusion for moving such.

[0009]

[Operation] According to this structure, when the gas generator of the pretensioner is activated by the detection action of the collision sensor,
Due to the gas pressure generated by the gas generator, the piston in the cylinder portion of the pretensioner moves to pull the wire, and the spool is rotated in the seat belt winding direction to instantaneously wind up the slack of the seat belt. At the same time, since the protrusion of the movable clamp is pushed by the cam that rotates in synchronization with the spool rotated by the wire, the movable clamp of the clamp mechanism is momentarily pushed to the fixed clamp side, and the movable clamp is moved. The seat belt is squeezed between and by the fixed clamp, and the movement of the seat belt in the pull-out direction is reliably locked.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings by giving the same reference numerals to the same parts as those in the conventional example.

1 to 3, the retractor body 1 is shown.
In the housing 2, the gas generator 7 that operates based on the detection action of the collision sensor 6, the cylinder portion 8 that houses the piston 9 that operates by the gas pressure generated by the gas generator 7, and the one end portion 10a are connected to the piston 9. The pretensioner 5 is provided with a wire 10 that is pulled by the operation of the piston 9 and that rotates the spool 3 in the winding direction of the seatbelt 4, and the seatbelt 4 is fixed by the fixed clamp 12 and the movable clamp 13. The basic structure is similar to that of the conventional example, in that a clamp mechanism 11 is provided for clamping the seat belt 4 to lock the movement of the seat belt 4 in the pull-out direction.

In the present embodiment, the cam portion 20 is provided on the spool 3 so as to project therefrom, and when the spool 3 is rotated by the gas pressure generated by the gas generator 7, the cam portion 20 is operated by the cam portion 20. A protrusion 13f is formed on the movable clamp 13 at the pushed position, that is, at a position close to the free end 13e side of the movable clamp 13.

Reference numeral 21 is a cover for covering the spool 3 of the housing 2 from the outside. Reference numeral 24 indicates the first pin 13 a of the movable clamp 13 because the protrusion 13 f of the movable clamp 13 projects outside the housing 2.
It is an opening formed in an arc shape centered on.

According to the structure of the above embodiment, the collision sensor 6 senses and operates when the vehicle collides, and the pretensioner 5 is activated.
When the gas generator 7 of FIG. 1 is actuated to move the piston 9 in the cylinder portion 8 of the pretensioner 5 by the gas pressure generated by the gas generator 7 and pull the wire 10, the state of FIG. 1 to the state of FIG. In addition, the spool 3 moves relative to the shaft 22 of the bobbin (not shown) from the broken line position in FIG.
The second planetary gear 23 meshes with the internal gear 3a of the spool 3, and the spool 3 is rotated in the direction of the arrow in FIG. 2, that is, in the winding direction of the seat belt 4 to instantly wind up the slack of the seat belt 4.

At the same time as the operation of the pretensioner 5,
The cam portion 20, which is rotated by the wire 10 and moves relatively upward, is rotated by the cam portion 20, so that the protrusion 13f of the movable clamp 13 is changed from the state shown in FIG. 1 to the state shown in FIG. By being pushed, the free end portion 13e of the movable clamp 13 of the clamp mechanism 11 instantly pushes to the locking surface 12a side of the fixed clamp 12, and as shown in FIG. The seat belt 4 is squeezed by and to securely lock the movement of the seat belt 4 in the pull-out direction.

FIG. 4 shows a time chart of the above-mentioned operation. When the collision sensor 6 detects and operates in step 100,
In step 101, the pretensioner 5 is immediately activated,
When the winding of the slack of the seat belt 4 is completed in step 102, the rotation of the spool 3 in the pull-out direction of the seat belt 4 is locked by the operation of an emergency locking mechanism (not shown) in step 103, and at the same time, in step 104, the clamping mechanism. 11 operates to lock the movement of the seat belt 4 in the pull-out direction.

Therefore, immediately after the slack winding of the seat belt 4 by the pretensioner 5 is completed, the clamp mechanism 11 can reliably lock the withdrawal of the seat belt 4 in step 104, and the restraint performance for the occupant can be further improved. Of.

Incidentally, in the conventional structure, as shown in FIG.
In the time chart of FIG. 3, since the seat belt 4 is pulled out by the inertial movement of the occupant after the emergency lock mechanism is activated in step 103, the clamp mechanism 11 is activated. Therefore, after the pretensioner 5 is activated, the clamp mechanism 11 is activated. The seat belt 4 is pulled out before the actuation of the seat belt 4, and the effect of preventing the slack of the seat belt 4 by the pretensioner 5 is diminished.

[0019]

As described above, according to the present invention, as the seat belt retractor, the gas generator is operated based on the detection action of the collision sensor, and the piston in the cylinder portion is moved by the gas pressure generated by the gas generator. And a pretensioner for winding the slack of the seat belt by rotating a spool by pulling a wire whose one end is connected to the piston, and pressing the movable clamp against the fixed clamp. In a structure including a clamp mechanism that clamps the seat belt with a movable clamp to lock the movement of the seat belt in the pulling-out direction, a cam portion protruding from the spool and movable together with the movable clamp, and a free movement of the movable clamp. Projected on the end side, the locking surface of the fixed clamp is pressed by the cam portion of the spool. According to this structure, when the gas generator of the pretensioner is activated by the detection action of the collision sensor, the generated gas pressure of the gas generator causes The piston in the cylinder part of the pretensioner moves to pull the wire, and the spool is rotated in the seatbelt winding direction to instantaneously wind up the slack of the seatbelt, and at the same time, the spool is rotated by the wire. Since the protrusion of the movable clamp is pushed by the moved and rotated cam portion, the movable clamp of the clamp mechanism is momentarily pushed to the fixed clamp side, and the seat belt is clamped by the movable clamp and the fixed clamp. It securely locks the movement of the seat belt in the pull-out direction, so that the seat belt After winding the completion of the bets, the withdrawal of the seat belt is reliably prevented, occupant restraining performance can further improve, has a practical benefit effect that it is possible to further enhance the safety.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view showing an embodiment of the present invention.

FIG. 2 is a partially cutaway side view showing an operating state of the embodiment.

FIG. 3 is a partially exploded perspective view showing the same embodiment.

FIG. 4 is a time chart diagram of the operation of the embodiment.

FIG. 5 is a side view showing a structure of a conventional example.

[Explanation of symbols]

 3 Spool 4 Seatbelt 5 Pretensioner 6 Collision sensor 7 Gas generator 8 Cylinder part 9 Piston 10 Wire 11 Clamp mechanism 12 Fixed clamp 13 Movable clamp 13e Movable clamp free end 13f Movable clamp protrusion 20 Cam part

Claims (1)

[Claims] 1. A gas generator is operated based on the detection action of a collision sensor, a piston in a cylinder portion is moved by the gas pressure generated by the gas generator, and a wire having one end connected to the piston is pulled. A pretensioner for rotating the spool to wind up the slack of the seat belt is provided, and the movable clamp is pressed against the fixed clamp, and the seat belt is squeezed between the fixed clamp and the movable clamp to pull out the seat belt. In a structure provided with a clamp mechanism for locking the movement in a direction, a cam portion protrudingly provided on the spool and movable therewith, and a fixing portion provided on the free end side of the movable clamp by the cam portion of the spool A seam characterized by being provided with a protrusion for moving the locking surface of the clamp so that it can be pressed. Belt retractor.