JP2697697B2 - Starter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seat belt tightening device for rotating a winding shaft of a retractor in a seat belt retracting direction at the time of a vehicle collision, or an impact at the time of collision of an occupant by an air bag rapidly inflated with gas. The present invention relates to an improvement of an activation device for operating an airbag device that protects the airbag device.

[0002]

2. Description of the Related Art In recent years, passive restraint devices such as seat belt tightening devices and airbag devices have been widely used for the purpose of protecting occupants in an emergency such as a vehicle collision.
For example, the seat belt tightening device is configured such that a piston is connected to one end of a cord that is wound around a pulley that is attached to a winding shaft (shaft) of a retractor, and the piston is slidably received in a cylinder. With the thrust by the expansion pressure of the acting gas, tension is applied to the cable body, and the cable body pulls the shaft of the retractor in the webbing winding direction, thereby driving the webbing in a state of being wrapped around the occupant. It is for emergency use. Therefore,
In the case of the seat belt tightening device, the seat belt tightening device includes a gas generator that acts on a piston in a cylinder to supply a gas pressure for exerting a tension on the cord, and the gas generator includes an ignition heater and an explosive. The ignition heater is energized by a signal from a collision sensor, and the explosive is ignited by the heat generated by the ignition heater to generate gas.

In the airbag device, a module composed of, for example, a center pad, a folded airbag, an inflator (gas generator) and the like is housed in a steering wheel. By instantly inflating the airbag with the rapidly burned gas, the inflated airbag receives the occupant's body and suppresses the impact force applied to the human body. Therefore, in the case of the airbag device, the airbag device has a gas generator for supplying an inflation gas for inflating the airbag, and the gas generator ignites an ignition charge to ignite a propellant. , The propellant burns rapidly to generate inflation gas.

Therefore, in each of the gas generators of the seat belt tightening device and the airbag device as described above, a starting device for igniting an igniter for operating these gas generators after detecting a vehicle collision is required. Becomes These starting devices include, for example, Japanese Patent Application Laid-Open Nos.
In general, an ignition device disclosed in, for example, JP-A-96456, energizes an ignition heater provided in an ignition charge by a signal from a collision sensor and ignites the ignition charge by the heat generated by the ignition heater. Was used.

However, these parts require a vehicle body acceleration detecting means such as an acceleration sensor for detecting a vehicle collision or the like and generating an ignition signal, and a control circuit for judging whether or not to energize the ignition heater based on the ignition signal. As the number of points increases, the structure becomes complicated, and furthermore, the reliability of the system must be assured by securely connecting the wires connecting the respective constituent means. There was a problem that it would.

Therefore, as in the starting device disclosed in Japanese Patent Application Laid-Open No. 4-108049, the ignition pin is caused to collide with a detonator provided on the igniter by the movement of a weight which also serves as an acceleration sensor of the vehicle body. There is a mechanical starter that ignites an igniter by an impact and eliminates the need for a complicated control circuit. The activation device swings the trigger shaft by movement of a weight that is an inertial body, and removes a stopper portion of the trigger shaft that is in contact with a flange portion of the ignition pin, thereby causing the ignition pin to jump out by the force of the compression spring. Is configured to strike a primer.

[0007]

However, in the case of the starting device in which the ignition pin collides with the primer provided on the ignition charge as described above, the contact portion between the stopper of the trigger shaft and the flange of the ignition pin is long. There is a possibility of rusting or sticking in between, and it is difficult to stabilize the friction coefficient of the contact portion. Also, in addition to the vibration at the time of collision, various vibrations such as vibrations when the door is closed or the body is hit are applied to the weight which is the body acceleration detection means. There is a problem that the possibility increases, the acceleration detection characteristic is hard to change, and the system has a small degree of freedom in design.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems, and to provide an inexpensive starting device which has a simple structure and is easy to assemble while preventing malfunction and improving reliability.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a gas generator including a detonator for operating the gas generator.
A starting device located adjacent to the center facing the primer
Moveable in the direction of the primer along the axis and engaged
Has a part, and the ignition pin can be ignited該雷tube by colliding with detonator consists columnar permanent magnet which can be moved into the detonator direction, the object to be engaged relates direction of movement of the ignition pin
Engagement that can engage with the engaged part from the side of the joint part far from the primer
An inertial body having one of the N and S poles formed on the side near the primer and the other pole formed on the other side, and an inner diameter through which the inertial body can pass. And the above ignition pin
An annular permanent magnet disposed between the inertial body and the primer in the moving direction, the one pole being formed on the side close to the inertial body, and the other pole being formed on the side near the primer. This is achieved by an activation device characterized in that:

[0010] Preferably, the inertial body is provided with a through hole through which the ignition pin passes. Preferably, the ignition pin and the inertial body are provided coaxially with respect to a moving direction. Preferably, the ignition pin is made of a non-magnetic material. Preferably, the ignition pin, the inertial body, and the annular permanent magnet are provided in a trigger case. Preferably, the ignition pin is connected to a primer.
A firing pin for hitting the primer is formed at the front end, which is the near side, and the rear end, which is far from the primer , is attached to the trigger case.
It is slidably inserted, and the engaged portion is located between both ends.
All the flanges are formed . Also preferably, a trigger
A trigger for holding the case;
The case covers the trigger case and is fixed to the mounting member
Mounting member via cushioning material filled in the mounting cover
Is held . Also, preferably, the trigger case is housed.
Projected in the direction perpendicular to the direction of movement of the ignition pin
The flange has a flange facing the primer side.
And the other part of the flange is made of cushioning material.
It is covered . More preferably, the activation device is:
It is used in a seat belt tightening device that drives a retractor by rotating it in a seat belt retracting direction at the time of a vehicle collision by driving with gas pressure.

[0011]

According to the above construction of the present invention, the inertial body itself, which has undergone acceleration in the direction of the primer above a predetermined value at the time of a vehicle collision, becomes
In the direction of movement, and the engaging portion of the inertial body is engaged by the ignition pin.
Kinetic energy (impact energy) can be directly applied to the primer by engaging with it , so that the trigger shaft or ignition pin that releases the restriction on the movement of the ignition pin according to the movement of the inertial body is urged toward the primer. This eliminates the need for an urging member, thereby simplifying the structure and increasing the impact energy to the primer in accordance with the magnitude of the acceleration acting on the inertial body. Further, by holding the surroundings of the starting device except for the inertial body moving direction side with a cushioning material, a shock absorbing material, or the like, the sensitivity of the starting device to a pulse-like acceleration from a direction other than the front collision direction with the vehicle body can be reduced. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. The retractor 1 with a pretensioner shown in FIG. 1 includes a take-up reel 2 on which a webbing 16 is wound up or pulled out freely, and the take-up reel 2 is driven by a take-up spring connected to the take-up shaft. ,
The webbing 16 is constantly urged in the winding direction. In the event of a collision, the rotation of the take-up shaft is prevented by the emergency lock mechanism 13 so that the webbing 16 is not pulled out any further.

In the retractor 1 with a pretensioner, the winding shaft is mounted on one of the base side walls of the retractor base 18 as a substantially U-shaped mounting member at the time of vehicle collision so that the slack of the seat belt is removed. A pretensioner 3, which is a seat belt tightening device that rotates in the direction of rotation, is provided. The pretensioner 3
Exerts tension on a wire 7 which is a transmission member wound around a pulley (not shown) attached to one end of the winding shaft, and the wire 7 draws the winding shaft in the webbing winding direction to drive the occupant. The webbing 16 is pulled in an emergency and has a driving means 4 for applying tension to the wire 7.

The driving means 4 includes a piston 6 connected to one end of a wire 7, a cylinder 5 for slidably receiving the piston 6, a base end of the cylinder 5, and gas ejection from a gas generator 8. 15 for communicating and connecting the parts
And a starter 21 disposed adjacent to the gas generator 8 to operate the gas generator 8 in response to acceleration equal to or higher than a predetermined value.
Consisting of The housing 15 is a substantially L-shaped tube member bent at a substantially right angle. A base end portion of the cylinder 5 is fixed to one opening 19 of the housing 15. , A wire 7 connected to the piston 6 is inserted.

At the periphery of the hole 20 in the housing 15, a tubular protective wall 17 is provided so as to protrude toward the opening 19, and is located in the housing 15 below the lower end surface of the piston 6. The wire 7 is connected to the protective wall 1
7. The gas generator 8 includes the explosive 1
1 is a case in which a primer 10 is incorporated in a case 12 sealed to a frame while accommodating the same. Then, when the primer 10 is hit and the explosive 11 is ignited, the inflation gas is ejected from the gas ejection portion at the tip of the case 12. And the gas generator 8
The activating device 2 that strikes the primer 10 is located beside the primer 10
1 is arranged.

The starting device 21 is made of a non-magnetic material such as stainless steel, and extends along a central axis facing the primer.
To the left (in the figure, left direction) and the engaged portion
It has a flange portion 22b serving as a ignitable ignition pin 22該雷tube 10 by colliding with the detonator 10, the detonator direction
And the through-hole 2 that passes through the ignition pin 22
3a is Ri Do a cylindrical permanent magnet provided along the central axis, the flange portion 2 relates to a mobile direction of the ignition pin 22
2b which can be engaged with the flange 22b from the side farther from the primer.
It has a primer side end 23b which is a joint part, and a side near the primer 10
An inertia body 23 having an S pole and an N pole on the other side has an inner diameter larger than the outer diameter of the inertia body 23.
The inertial body 23 and the lightning
S is disposed between the tube 10 and the side close to the inertial body 23.
A pole is formed, and an N pole is formed on the side near the primer 10.
An annular permanent magnet 24 and a trigger case 25 internally provided with the magnet and fixed to the retractor base 18. Therefore, the ignition pin 22 and the inertial body 23 are disposed coaxially in the moving direction.

The ignition pin 22 is located on the side near the primer 10.
With firing pin 22a to strike the detonator 10 to a distal end portion is formed, the rear end portion bets is the side remote from the detonator 10
Slidably fitted into the bottom wall 25c of the rigger case 25
The flange 22b is formed between both ends, and is provided inside the trigger case 25. At this time, the firing pin 22a
Penetrates through the opening 25b formed in the wall 25a of the trigger case 25 on the primer side, contacts the primer 10, and the flange 22b faces the inner wall surface of the wall 25a with a gap. Then, when the inertial body 23 collides with the flange portion 22b, the ignition pin 22 moves to the primer side, and the firing pin 22a strikes and ignites the primer 10.

The annular permanent magnet 24 is fitted in the primer side (the left side in the figure) of the trigger case 25, and the inertial body 23 loosely inserted into the ignition pin 22 is attached to the bottom of the trigger case 25. It is installed on the wall side (right side in the figure).
At this time, in the annular permanent magnet 24 and the inertial body 23 arranged so that adjacent magnetic poles are the same, the relative position H of the primer side end 23b to the bottom wall side end 24a (however, the primer side end 23b The relationship between the position of the magnetic field and the repulsion / attraction force of the magnetic force is as shown in the graph of FIG.

Therefore, the primer side end 23b has a distance h from the bottom wall side end 24a, and the adjacent magnetic poles have the same polarity (in the figure,
The inertial body 23 arranged so as to be (S pole-S pole) is urged toward the bottom wall away from the primer 10 by the repulsive force of the magnetic force. That is, the inertial body 23 is
Is slidable in the axial direction along the axis, but a force in the direction of the primer which is greater than the repulsive force of the magnetic force acting between the annular permanent magnet 24 and the inertial body 23 exerts a force on the inertial body 23. If it does not act, the inertial body 23 cannot move in the direction of the primer, so that the activation device 21 does not operate.

If the inertial force of the inertial body multiplied by the weight of the inertial body 23 and the acceleration in the primer direction becomes larger than the repulsive force of the magnetic force, the inertial body 23 moves in the primer direction as shown in FIG. . Further, when the inertial body 23 moves to a region where the magnetic attraction force acts on the inertial body 23, the inertial body 2
3 is accelerated in the direction of the primer by the attractive force of the magnetic force, is inserted into the opening of the annular permanent magnet 24, and collides with the flange 22b.

That is, at the time of vehicle collision, the direction of the primer
Inertial body 23 itself accelerates toward the primer
The primer end 23b of the inertial body 10 is a flange of the ignition pin 22.
Since the impact energy is directly applied to the primer 10 by colliding with the portion 22b , the starting device 21 has a simple structure and is easy to assemble, and the starting device 21 is applied to the primer 10 in accordance with the magnitude of the acceleration acting on the inertial body 23. Impact energy can be increased. In addition, since there is no member that presses against the ignition pin 22 or the inertial body 23, there is no fear that the press-contact portion rusts or sticks for a long time to cause malfunction of the activation device 21, and stable operation is ensured. can do. Further, by changing the strength of the magnetic force, the relative positional relationship between the annular permanent magnet 24 and the inertial body 23, and the like, the acceleration detection characteristics can be easily changed, so that the degree of freedom in designing the system is increased.

Next, the operation of the retractor 1 with a pretensioner will be described. In a normal running state of the vehicle, the pretensioner 3 is not engaged with the winding shaft, so that the winding shaft is freely rotatable. Therefore,
The webbing 16 can be wound by the biasing force of the winding spring, and the webbing 16 can be pulled out against the spring force.

When a certain degree of deceleration such as sudden braking occurs in the vehicle, the emergency locking mechanism 1 of the retractor
3 operates to lock the rotation of the winding shaft. Thus, the extension of the webbing is prevented, but the inertial body 23
Is smaller than the repulsive force of the magnetic force acting between the annular permanent magnet 24 and the inertial body 23, and the activation device 21 does not operate, so the driving means 4 of the pretensioner 3 does not operate. .

On the other hand, when an extremely large predetermined deceleration occurs at the time of a vehicle collision or the like, the inertial force acting on the inertial body 23 is reduced by the magnetic force acting between the annular permanent magnet 24 and the inertial body 23. Since the inertia body 23 moves in the direction of the primer and collides with the flange 22b, the ignition pin 22 strikes the primer 10 and ignites. The ignition of the primer 10 causes the gas generator 8 in the driving means 4 to ignite, and when the gas generator 8 generates combustion gas in the cylinder 5, the piston 6 rapidly moves upward (arrow) due to the pressure of the generated gas. X direction). Due to the driving force of the piston 6, the wire 7 is moved by a predetermined amount of force to the arrow X.
When the webbing is rapidly pulled in the direction, the take-up shaft is driven in the webbing take-up direction, so that the webbing 16 that has been stretched over the occupant is pulled in, and the play of the seat belt is eliminated.

Accordingly, there is no need for a vehicle body acceleration detecting means such as an acceleration sensor for detecting a vehicle collision or the like and generating an ignition signal, and a control circuit for judging whether to energize the ignition heater based on the ignition signal. Is simpler, and wiring for connecting the respective constituent means is not required. Therefore, the retractor 1 with the pretensioner can achieve a large cost reduction while having high reliability.

FIG. 4 is a partial sectional view of a driving means 33 of a retractor 30 with a pretensioner according to another embodiment of the present invention. The same reference numerals are given and the description is omitted. Starting device 31 in the present embodiment
Has an ignition pin 22, an inertial body 23, an annular permanent magnet 24, and a trigger case 25 in which these are provided, similarly to the starting device 21 in the above embodiment. Is not directly fixed to the retractor base 18, but through a cushioning material 34 such as urethane foam filled in a mounting cover 32 fixed to the retractor base 18 so as to cover the trigger case 25. Is held. That is, the activation device 31 is loosely fitted into the opening 18 a formed in the retractor base 18, and the ignition pin 22 in which the trigger case 25 is accommodated is moved.
It has a flange part 25d protruding in the direction perpendicular to the movement direction.
The surface of the flange portion 25d facing the primer 10 side is open.
18a and the other part of the flange portion 25d
Since it is covered with the cushioning material 34, it is in a so-called floating state in which it can move in a direction other than the primer side.
In addition, the trigger case 2 is provided on the inner peripheral wall of the mounting cover 32.
In order to prevent the firing pin 22a from hitting the primer 10 due to the lateral displacement of 5, a tubular projection 32a is provided to restrict the lateral displacement to a predetermined value or less.

Therefore, the impact in the forward collision direction (right direction in the figure) at the time of the vehicle collision is transmitted directly to the trigger case 25 via the contact portion of the flange portion 25d with the retractor base 18. Shocks in directions other than the above, the trigger case 2
5 so that it is attenuated. Therefore, the activation device 31
Is less sensitive to pulse-like acceleration in directions other than the frontal collision direction than in the frontal collision direction, preventing accidental operation due to inadvertent impacts such as vibration when closing the door or hitting the body As a result, the sensitivity in the frontal collision direction can be increased, and the acceleration detection characteristics can be easily changed.

In each of the above embodiments, the starting device of the present invention is applied as a starting device for operating the gas generator of the seat belt tightening device. However, the present invention is not limited to this. It can also be applied to an actuating activation device. In addition, each member constituting the activation device of the present invention is not limited to the shape in each of the above-described embodiments, but may take various forms based on the gist of the present invention.

[0029]

According to the starting device of the present invention, when a vehicle collides,
The inertial body itself that has accelerated in the direction of the primer over a predetermined
Moves toward the primer, and the engaging portion of the inertial body is
Since the impact energy to the primer is directly applied by engaging with the engaging portion , the structure is simple and easy to assemble, and the impact energy to the primer can be increased according to the magnitude of the acceleration acting on the inertial body. . In addition, since there is no member that presses against the ignition pin or the inertial body, there is no fear that the press-contact portion is rusted or adhered for a long time and the starting device malfunctions, and stable operation can be ensured. Furthermore, by holding the surroundings of the starting device other than the inertial body moving direction side with a shock absorbing material or a shock absorbing material, the sensitivity of the starting device to a pulse-like acceleration from a direction other than the frontal collision direction with the vehicle body can be reduced. Also, malfunction due to inadvertent impact such as vibration when the door is closed or the body is hit is prevented.

Therefore, it is possible to provide an inexpensive starting device that has a simple structure and is easy to assemble, while preventing malfunction and improving reliability.

[Brief description of the drawings]

FIG. 1 is a sectional front view of a main part of a retractor with a pretensioner according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the retractor with a pretensioner shown in FIG.

3 is a graph showing a relationship between a relative position H between an annular permanent magnet and an inertial body in FIG. 1 and a repulsion / attractive force of a magnetic force.

FIG. 4 is a sectional front view of a main part of a retractor with a pretensioner according to another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 retractor with pretensioner 2 take-up reel 3 pretensioner 4 drive means 5 cylinder 6 piston 7 wire 8 gas generator 10 detonator 11 gunpowder 12 case 13 emergency lock mechanism 15 housing 16 webbing 17 protective wall 18 retractor base 19 opening 20 Hole 21 Starting device 22 Ignition pin 23 Inertia body 24 Ring permanent magnet 25 Trigger case

Claims (9)

(57) [Claims] 1. To operate a gas generator including a primer.
A starter arranged adjacent to the gas generator, the starter being movable in the direction of the primer along a central axis facing the direction of the primer.
It has an engaged portion and comprises a firing pin capable of igniting the squib by colliding with the squib, and a columnar permanent magnet made movable in the squib direction ,
With respect to the moving direction of the ignition pin, from the primer of the engaged portion
A detonator having an engagement portion engageable with the engaged portion from a distant side;
An inertial body in which one of the N and S poles is formed on the side closer to and the other side is formed with the other pole; and an inner diameter that allows the inertial body to pass through . Move
An annular permanent magnet disposed between the inertial body and the primer in the direction, the one pole being formed on the side close to the inertial body, and the other pole being formed on the side near the primer. An activation device, characterized in that: 2. The starting device according to claim 1, wherein the inertial body is provided with a through hole through which the ignition pin passes. 3. The starting device according to claim 2, wherein the ignition pin and the inertial body are provided coaxially in a moving direction. 4. The ignition pin according to claim 1, wherein the ignition pin is made of a non-magnetic material.
An activation device as described. 5. The starting device according to claim 1, wherein the ignition pin, the inertial body, and the annular permanent magnet are provided inside the trigger case. 6. A firing pin for hitting the priming is formed at the tip of the ignition pin which is closer to the priming, and is far from the priming.
The rear end, which is the side, is slidably fitted into the trigger case.
And a flange portion as the engaged portion is formed between both end portions.
Activation device according to claim 5, wherein that. 7. A mounting for holding a trigger case.
The trigger case covers the trigger case.
Looseness filled in the mounting cover fixed to the mounting member
6. The activation device according to claim 5, wherein the activation device is held by the mounting member via an impact material . 8. A trigger case is provided for the ignition pin to be accommodated.
It has a flange protruding in the direction perpendicular to the moving direction,
The surface of the flange facing the detonator contacts the mounting member
Other parts of the flange are covered with cushioning material.
Activation device according to claim 7 that. 9. used in the seat belt tightening device for rotating the seat belt retraction direction during a vehicle collision the winding shaft of the retractor by driving gas pressure, the gas in order to actuate the gas generator including a detonator Adjacent to generator
A starting device that is arranged and can move in the direction of the primer along the central axis that faces the direction of the primer.
It has an engaged portion and comprises a firing pin capable of igniting the squib by colliding with the squib, and a columnar permanent magnet made movable in the squib direction ,
In the moving direction of the ignition pin, it is far from the primer of the engaged portion.
From the side to be engaged with the engaged portion.
Is one of the pole formation of N · S pole on the side close, the inertial body on the other side of the other pole is formed, has an inner diameter of the inertial body can pass, the movement of the ignition pin
An annular permanent magnet disposed between the inertial body and the primer in the direction, the one pole being formed on the side close to the inertial body, and the other pole being formed on the side near the primer. An activation device, characterized in that: