JP2000127895A - Pretensioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pretensioner capable of rotating a seat belt winding shaft smoothly and efficiently, easily sealing high pressure gas for driving and miniaturizing a gas pressure resistant container. SOLUTION: A casing 11 of a pretensioner 1 is pierced with a winding shaft 3. A pressure container 13 is fitted to the upper part of the casing 11. An upper end opening part 13a of the pressure container 13 is equipped with a gas generator 15. Solid material 20 is stored inside the pressure container 13, and a guide groove 21 is connected to a lower end opening part 13b. A sleeve 25 provided with clutch mechanism 30 is fitted to the winding shaft 3. Tapes 36, 37 are respectively fixed to the sleeve 25, and the center part is made rotating blades 26, 27. The outer ends of the rotating blades 26, 27 reach the guide groove 21 and respectively form a driving point A and a driving point B. Interposed bodies 40 are held in the guide groove 21 between the driving points A, B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pretensioner incorporated in a seat belt device for restraining an occupant to a seat of a vehicle or the like and urgently rotating a winding shaft of the seat belt in a winding direction. In particular, the present invention relates to a pretensioner that can easily seal a high-pressure gas for driving and can realize a compact gas pressure container and can smoothly and efficiently rotate a winding shaft of a seat belt.

[0002]

2. Description of the Related Art In recent years, seat belt devices equipped on vehicles such as automobiles have been increasingly equipped with a pretensioner. This pretensioner urgently rotates a reel (winding shaft) for winding a seat belt in a winding direction at the time of a vehicle collision. A device for driving the pretensioner generally ignites explosives based on a detection signal transmitted at the time of a vehicle collision, and drives the reel rotating mechanism by the gas pressure generated thereby.

[0003] Such a pretensioner is disclosed in, for example, Japanese Patent Publication No. 2-10743 and Japanese Patent Application Laid-Open No. 10-8679.
No. 1 is known.

[0004] The pretensioner disclosed in Japanese Patent Publication No. Hei 2-10743 is equipped with an animal power device (drive device) such as an air cylinder that operates when a vehicle collides. This animal powerer is connected to a bobbin-shaped roller through a pulling member such as a flexible rope. This roller is connected to a belt shaft that winds the belt via a clutch. Then, when the animal power is activated at the time of the collision of the vehicle, the animal energy puller pulls the pulling member. As a result, the roller rotates, the clutch engages, and the roller and the belt shaft are connected. further,
When the pulling force of the animal power device acts on the pulling member and the roller rotates, the rotation of the roller is transmitted to the belt shaft. Thereby, the belt is wound in the winding direction.

On the other hand, the pretensioner disclosed in Japanese Patent Application Laid-Open No. 10-86791 has a driven shaft protruding from a reel around which a belt is wound. A rotating ring is coaxially arranged on the driven shaft via a clutch mechanism. A steel tape is attached around the rotating ring. The tape is stored in a storage chamber, and gas is supplied to the storage chamber by a gas generator. Then, when the gas generator is ignited at the time of collision of the vehicle, gas pressure is supplied into the storage chamber, and the pressing force of this gas acts to press the tape. Then, the rotating ring rotates via the tape, the clutch engages, and the rotating ring and the driven shaft are connected. When the pressing force of the gas acts on the tape and the rotating ring rotates, the rotation of the ring is transmitted to the driven shaft, and the belt is wound in the winding direction.

[0006] Apart from the pretensioners disclosed in these publications, there is also known a clutch using a rack and pinion as a clutch. In this method, the rack and the pinion are not engaged with each other in a normal state of the vehicle, and the rack is moved by the gas pressure only at the time of collision of the vehicle. When the rack moves and meshes with the pinion, the reel engaged with the pinion rotates in the belt winding direction.

[0007]

In recent years, the size and weight of seat belt devices have been reduced. For this reason, there is a strong desire to reduce the size and weight of the gas pressure vessel that is the source of the gas pressure. For that purpose, gas pressure must be efficiently used with a small amount of gas. However, in the structure of each of the above pretensioners, the obtained force is smaller than the amount of gas used, and the utilization efficiency is low. Further, in the above-mentioned tape type (JP-A-10-86691),
Since gas pressure is supplied to almost the entire area inside the pretensioner (tape storage chamber), sealing measures must be strictly performed over a wide range.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a gas seal can be easily performed and a compact gas pressure container can be realized, and the winding shaft of the seat belt can be smoothly and efficiently rotated. It is an object of the present invention to provide a pretensioner capable of causing the pretensioner to operate.

[0009]

In order to solve the above-mentioned problems, a pretensioner according to a first aspect of the present invention provides a pretensioner that applies a pretension to a belt by rotating a winding shaft of a seat belt in a winding direction in an emergency. A tensioner;
A driving member that drives the winding shaft and has a plurality of driving points around it; and an accelerator that injects a solid to push one or more of the driving points. Are provided at substantially equal angular intervals around the driving member. Since only torque acts on the winding shaft, no lateral load is applied to the winding shaft. Therefore, the rotation of the winding shaft becomes smoother.

A pretensioner according to a second aspect of the present invention is a pretensioner that applies pretension to a belt by rotating a winding shaft of a seat belt in a winding direction in an emergency; and driving the winding shaft. A driving member having a plurality of driving points around it, and an accelerator for injecting a solid so as to press one or more of the driving points,
Some of the driving points are directly pushed by the solid ejected from the accelerator, and others are indirectly pushed by the solid via a substantially incompressible interposition. It is characterized by the following. A small number of accelerators (in particular, one accelerator) can drive a plurality of portions of the drive member at the same time. Further, since the winding shaft is rotated at a plurality of driving points, the rotation efficiency can be improved.

Further, a pretensioner according to a third aspect of the present invention is a pretensioner for applying a pretension to a belt by rotating a winding shaft of a seat belt in a winding direction in an emergency; A driving member having a plurality of driving points around it, and an accelerator for injecting solids so as to press the driving points, wherein the peripheral speed of the driving points is faster than the speed of the injected solids. And a speed increasing mechanism. The speed increasing mechanism can speed up the winding of the winding shaft. This allows
A wide range of specifications of the acceleration means of the accelerator can be selected, and the degree of freedom in design is increased.

In the present invention, the driving member is formed of a tape having one end attached to a take-up shaft side and the other end fixed to a casing or the like of a pretensioner. By pushing, the driving member can be driven. According to such a driving member, the solid matter ejected from the accelerator rotates the winding shaft via the tape. Therefore, the gas pressure can be used more efficiently than when the tape is directly driven by the gas pressure. Further, since the gas seal only needs to be performed on the accelerator part, the sealing measure is facilitated.

In the present invention, a plurality of the tapes are provided around the winding shaft at substantially equal angular intervals, and an intervening body is arranged between the plurality of band-shaped members. I can do it. The solid matter injected from the accelerator first comes into contact with a tape (a belt-shaped member) closest to the accelerator. Then, the driving member pushes the second driving member via the intervening body. As described above, since the winding shaft is rotated at a plurality of driving points, the rotation efficiency is improved, and the rotation of the winding shaft becomes smoother.

Further, according to the present invention, there is provided a guide groove for guiding the solid matter, wherein the guide groove is circularly curved so as to surround the winding shaft, and the solid matter is formed from a plurality of granular materials. Can be. On the other hand, the guide groove may be formed in a straight line, and the solid may be formed in a rod shape. Solid matter ejected from the accelerator moves along the guide groove. A solid material composed of a plurality of granular materials can move satisfactorily in a circularly curved guide groove. On the other hand, since the rod-shaped solid moves linearly along the linear guide groove, the energy loss is smaller.

In the present invention, the driving member may include a hollow cylinder fitted to the winding shaft, and a clutch mechanism may be provided between the hollow cylinder and the winding shaft. . Thus, when the pretensioner is operated (at the time of collision of the vehicle), the winding shaft and the hollow cylindrical body can transmit torque reliably and rapidly.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIGS. 1 to 3 show a first embodiment of the present invention. FIG. 1 is a front sectional view showing a state before operation of a pretensioner according to the present invention. FIG. 2 is a front sectional view showing a state after the operation of the pretensioner. FIG. 3 is a sectional view of a groove of the pretensioner.

The pretensioner 1 shown in FIGS. 1 to 3 is incorporated in a seat belt retractor. The seat belt retractor includes a reel around which the belt 5 is wound, a frame that rotatably supports the reel, a return spring that urges the reel in a winding direction, and a belt withdrawal direction in a case where the vehicle suddenly decelerates. An emergency lock mechanism or the like for preventing rotation of the motor is provided. Although not shown, the components of the seat belt retractor are conventionally known.

A winding shaft 3 fixed to the reel passes through the inside of the casing 11 of the pretensioner 1.
The winding shaft 3 is provided along the axis of the reel, and rotates synchronously with the reel. Casing 1
1 is made of an aluminum die-cast member or the like. The casing 11 includes a board 11a (see FIGS. 1 and 2) directly attached to the frame, and a lid plate 11b (see FIG. 3) arranged to face the board 11a.

A cylindrical pressure vessel (accelerator) 13 is attached to an upper portion of the casing 11. The middle part of the pressure vessel 13 projects in a flange shape. This overhang is fixed to the upper part of the casing 11. The gas generator 1 is located at the upper end opening 13a of the pressure vessel 13.
5 is equipped. The gas generator 15 ignites an explosive based on a detection signal transmitted at the time of a vehicle collision and supplies gas pressure to the inside of the pressure vessel 13.

Inside the pressure vessel 13, solids (balls) 20-1 to 20-4 arranged in the axial direction are accommodated. Each of these solids 20 is made of a resin or metal spherical body. The solid material 20 is provided at the lower end opening 13 b of the pressure vessel 13.
Due to the lid 16 fixed to the cover, it cannot be dropped or protruded in normal times. The lower end opening 13b of the pressure vessel 13 has a lid 1
A guide groove 21 is provided continuously through the reference numeral 6. This guide groove 2
Reference numeral 1 is circularly curved so as to surround the winding shaft 3 in the casing 11. The guide groove 21 is shown in FIG.
, As best shown in FIG. The groove 22 is formed on the substrate 11a side,
Reference numeral 3 is formed on the lid plate 11b side. The groove width and interval of each groove 22 and 23 are sized so that the solid 20 can move smoothly.

On the other hand, a hollow cylindrical sleeve 25 having a clutch mechanism 30 is attached to the winding shaft 3. The clutch mechanism 30 transmits the rotational driving force of the sleeve 25 to the winding shaft 3 only at the time of a vehicle collision, and has a conventionally known structure (Japanese Patent Application Laid-Open No. 10-86791, Japanese Patent Publication No. Hei 2-10743). Etc.)
Can be adopted. On the outer peripheral surface of the sleeve 25, two shallow grooves 25a and 25b are formed. These grooves 25a, 2
5b are formed at positions that are parallel to the axis of the sleeve 25 and that are 180 ° apart from each other in the circumferential direction and face each other. In these grooves 25a and 25b, a steel tape 3
The inner ends of 6, 37 are fixed respectively. These tapes 36 and 37 are wound around the outer periphery of the sleeve 25.

The center portions of the tapes 36 and 37 are rotating wings 26 and 27, respectively. The rotating wings 26 and 27
It is located between the base plate 11a of the casing 11 and the lid plate 11b, and is positioned one to the left and right (left and right in FIGS.
It extends toward the position facing 80 °. Therefore,
As with the tapes 36 and 37, the two rotating wings 26 and 27 are arranged at equal angular intervals. The outer ends of the rotary wings 26 and 27 reach the outer peripheral portion of the guide groove 21, respectively, and are fixed at that position. The position of one rotary wing 26 in the guide groove 21 is the first drive point A, and the position of the other rotary wing 27 is the second drive point B.

Driving point A and driving point B of both rotating wings 26 and 27
Between the guide grooves 21, an intervening body 40 is held. The intervening body 40 is made of resin or metal. As shown best in FIG. 3, the intervening body 40 is composed of a small disk-shaped base 41 and projections 4 formed at the centers of both end faces of the base 41.
Consists of two. Each intervening body 40 is formed by a projection
3 and can be moved along the guide groove 21.

Next, the operation of the pretensioner 1 having the above configuration will be described. When the collision state of the vehicle is detected, a detection signal is transmitted to the gas generator 15.
By this detection signal, the gas generator 15 is ignited,
A gas pressure is supplied into the pressure vessel 13. The solid pressure is pushed by the gas pressure, and the lid 16 is broken. Lid 16
Is broken, the inside of the pressure vessel 13 is
The solids 20 are simultaneously ejected.

The lowermost solid 20-1 of the solids 20 injected into the guide groove 21 corresponds to the driving point A of the rotary blade 26. At this time, at the driving point A, the pressing force of all the solids 20 acts simultaneously. This pressing force is applied to the rotating wing 2
By acting on 6, the tape 36 is pulled out.
When the tape 36 is pulled out, the sleeve 25 to which the inner end of the tape is fixed rotates. By the rotation of the sleeve 25, the clutch mechanism 30 is engaged, and the sleeve 25
Is transmitted to the winding shaft 3, and the belt 5 starts rotating in the winding direction.

At the driving point A, at the same time as the pressing force of the solid 20 acts, the pressing force also acts on the intervening bodies 40, and these intervening bodies 40 move along the guide grooves 21.
Due to the movement of the intervening body 40, a pressing force (a pressing force from the intervening body 40) also acts on the driving point B, and the tape 37 is pulled out. Therefore, an event similar to that at the driving point A also occurs at the driving point B.

As described above, by pushing at the two driving points A and B and realizing a pulley mechanism using tape, the number of rotations of the winding shaft 3 is increased, the rotation efficiency is improved, and the power transmission efficiency is improved. Is enhanced. In particular, by providing two rotating blades 26 and 27 and pressing them at two symmetrical points, the rotational balance of the sleeve 25 and the winding shaft 3 is also ensured. In addition, the only necessary part of the gas seal is the pressure vessel 13 and the guide groove 2
No. 1 does not require a gas seal. Therefore, no gasket is required, and the casing 11 can be made thin.

[Second Embodiment] FIG. 4 is a front sectional view showing a state before operation of another pretensioner according to the present invention. FIG. 5 is a front sectional view showing a state after the operation of the pretensioner of FIG.

The pretensioner 50 shown in these figures is
As with the pretensioner 1 of FIGS.
, A pressure vessel 53, and a gas generator 55. A straight guide groove 61 is formed in the casing 51. The pressure vessel 53 and the guide groove 61 communicate with each other through a gas passage 52 formed in the casing 51. The guide groove 61 accommodates a bar-shaped solid 60. The solid material 60 is formed flat on the side near the pressure vessel 53 (rear end side), and is formed hemispherically on the opposite side (front end side).

The winding shaft 3 extends through the casing 51. In a region including the winding shaft 3, the casing 51
Are provided with recesses 58 and 59 communicating with the guide groove 61. A crescent-shaped spacer 66 is fixed to the recess 58 by two pins 62 and 63. Also, the recess 59
Has a single pin 64 implanted therein. The spacer 66 may be formed integrally with the casing 51 without using the pins 62 and 63. Further, the spacer 66 does not necessarily need to be provided, and may be simply the concave portion 58.

Further, the take-up shaft 3 has a clutch mechanism 70
A hollow cylindrical sleeve 65 provided with There is a gap between the sleeve 65 and the spacer 66. On the outer peripheral surface of the sleeve 65, two shallow grooves 65
a, 65b are formed. The ends of a steel tape 67 are fixed to the grooves 65a and 65b, respectively. The tape 67 is wound around the outer periphery of the sleeve 65 a plurality of times and fixed to the pins 64. Further, the middle of the tape 67 is wound around the outer periphery of the spacer 66 in a double loop and locked. The front end of the solid 60 contacts the tape 67 in the guide groove 61.

Next, the pretensioner 5 having the above configuration
The operation of 0 will be described. By transmitting the detection signal accompanying the collision state of the vehicle, the gas generator 55 fires and gas pressure is supplied into the pressure vessel 53. This gas pressure is supplied from the pressure vessel 53 to the guide groove 61 via the gas passage 52. Then, the solid object 60 is pushed upward in the drawing by the gas pressure supplied to the guide groove 61.

The solid 60 is formed into a guide groove 61 by gas pressure.
Go straight inside. As the solid 60 moves, the tape 67 is pulled out while being pressed. At this time, the inside of the loop portion of the tape 67 is tightened, and the outside of the loop portion is pulled out. As a result, the sleeve 65 rotates, the clutch mechanism 70 meshes, the rotation of the sleeve 65 is transmitted to the winding shaft 3, and the belt 5 starts rotating in the winding direction.

[0034]

As is apparent from the above description, the present invention has the following effects. (1) The rotation of the winding shaft becomes smoother and more efficient. (2) Since the winding shaft is rotated at a plurality of driving points, the rotation efficiency can be improved. (3) The specification of the acceleration means of the accelerator can be selected widely. Therefore, the degree of freedom in design increases. (4) A small-capacity and compact gas pressure-resistant container can be realized. (5) Countermeasures against gas leakage are facilitated.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a state before an operation of a pretensioner described in a first embodiment.

FIG. 2 is a front sectional view showing a state after the operation of the pretensioner.

FIG. 3 is a sectional view of a groove of the pretensioner.

FIG. 4 is a front sectional view showing a state before an operation of a pretensioner described in a second embodiment.

FIG. 5 is a front sectional view showing a state after the operation of the pretensioner.

[Explanation of symbols]

1, 50 Pretensioner 3 Winding shaft 5 Belt 15, 55 Gas generator 20, 60 Solid 21, 61 Guide groove 22, 23 Groove 25, 65 Sleeve 26, 27 Rotary wing 30, 70 Clutch mechanism 36, 37, 67 Tape 40 Intermediate A, B Drive point

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hikaru Kameyoshi 1-4-30 Roppongi, Minato-ku, Tokyo Inside Takata Corporation (72) Inventor Hiroki Takehara 1-4-30 Roppongi, Minato-ku, Tokyo Takata Stock In-house (72) Inventor Masahiro Shioya 1-4-30 Roppongi, Minato-ku, Tokyo Inside Takata Corporation (72) Inventor Hiromasa Tanji 1-4-30 Roppongi, Minato-ku, Tokyo F-term (reference) ) 3D018 MA02

Claims (8)

[Claims] 1. A pretensioner for applying pretension to a belt by rotating a winding shaft of a seat belt in a winding direction in an emergency; having a plurality of driving points around the driving point for driving the winding shaft. A driving member, and an accelerator for injecting a solid material to press one or more of the driving points, wherein the plurality of driving points are provided at substantially equal angular intervals around the driving member. A pretensioner characterized in that: 2. A pretensioner for rotating a winding shaft of a seat belt in a winding direction to apply pretension to a belt in an emergency; having a plurality of driving points around the driving shaft for driving the winding shaft. A driving member, and an accelerator for injecting a solid matter so as to push one or more of the driving points, wherein some of the driving points are directly pushed by the solid matter ejected from the accelerator. A pretensioner wherein the other is indirectly pushed by the solid through a substantially incompressible interposer. 3. A pretensioner for rotating a winding shaft of a seat belt in a winding direction in an emergency to apply pretension to a belt; having a plurality of driving points around the driving shaft for driving the winding shaft. A driving member, and an accelerator for injecting a solid to push the driving point, and a speed increasing mechanism for increasing the peripheral speed of the driving point to be higher than the speed of the injected solid. Pretensioner. 4. The driving member comprises a tape having one end attached to a take-up shaft side and the other end fixed to a casing or the like of a pretensioner, wherein the solid material pushes a central portion of the tape. The pretensioner according to any one of claims 1 to 3, wherein the driving member is driven. 5. A plurality of tapes are provided around the winding shaft at substantially equal angular intervals, and an intervening body is arranged between the plurality of strip-shaped members. The pretensioner according to claim 4. 6. The apparatus according to claim 1, further comprising a guide groove for guiding the solid material, wherein the guide groove is circularly curved so as to surround the winding shaft, and the solid material comprises a plurality of granular materials. The pretensioner according to any one of claims 1 to 5, wherein 7. The apparatus according to claim 1, further comprising a guide groove for guiding said solid material, wherein said guide groove is formed linearly, and said solid material is formed in a rod shape.
A pretensioner according to any one of the preceding claims. 8. The apparatus according to claim 1, wherein the driving member includes a hollow cylindrical body fitted to the winding shaft, and a clutch mechanism between the hollow cylindrical body and the winding shaft. The pretensioner according to any one of claims 1 to 7.