JP2697698B2 - 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. TECHNICAL FIELD The present invention relates to an actuation device for operating an airbag device to be protected from an airbag device, and more particularly to improvement of a malfunction prevention mechanism of the actuation 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.

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.

As a starting device for detecting a vehicle collision and activating the seat belt tightening device and the airbag device, for example, an operation of an inertial body which is displaced by an inertial force at the time of a collision of a vehicle is usually used for non-operation. There is a mechanical activation device that injects an ignition pin held in an operation position toward a primer, thereby igniting an igniter and activating the seat belt tightening device and the airbag device by the explosive force. .

[0005] By the way, the assembly (assembly) such as the seat belt tightening device and the airbag device provided with the mechanical activation device must not operate the activation device before being assembled to the vehicle. Therefore, it is necessary to provide a malfunction prevention mechanism in the starting device. Therefore, various mechanical activation devices having various malfunction prevention mechanisms have been proposed.

[0006] For example, a collision sensor (starting device) disclosed in Japanese Utility Model Laid-Open Publication No. 4-83862 and the like includes an ignition pin (ignition pin) urged toward a primer, an inertial body that is moved by a collision, and an inertial body. A rotating body (trigger means) having a lever for urging the inertial body in the anti-collision direction and locking the ignition pin, and further comprising an interference means for locking or releasing the inertial body or the lever. Equipment is provided. Therefore, the collision sensor is prevented from malfunctioning (exploding) by locking the movement of the inertial body by the interference member of the safety device which is brought to the lock or release position by the rotation of the rotation shaft.

However, in the case of the starting device in which the ignition pin collides with a primer provided on the ignition charge as described above, the ignition pin spring-biased by the coil spring and the inertial body are separate members. Therefore, even if the movement of the inertial body is restricted and the activation device is deactivated, the trigger pin is released due to some unexpected factor because the ignition pin maintains the collision energy for igniting the detonator. In some cases, the ignition pin may move and the starter may operate.

[0008] This is because the inertial body is arranged in a limited space, it is difficult to increase the energy for moving the trigger means, and the starting device from when the inertial body moves until the ignition charge is ignited. Since the response time of the ignition pin must be shortened, the amount of engagement at the contact portion between the trigger means for engaging the ignition pin and the ignition pin is generally reduced, and the ignition pin can be engaged even by a slight movement of the trigger means. This is because it is set to deviate. Therefore, there is a problem that if an impact such as a drop is given to an assembly provided with these activation devices or a case of the activation device is deformed or the like, the trigger means is easily released carelessly.

Therefore, the acceleration sensor disclosed in Japanese Patent Application Laid-Open No. 64-85856 has a resilient support in a direction opposite to the acceleration so as to be displaced by an inertial force when an acceleration of a predetermined value or more is applied. A part that interferes with the displacement of the sensor mass (inertial body) that has been moved, and a part that interferes with the displacement of the energy releasing means (ignition pin) that is always resiliently supported so as to be displaceable toward the operating position where energy is released. It has a safety device (malfunction prevention mechanism) including a set member that each has. That is, by setting the state in which the displacement of the inertial body and the ignition pin are both restrained by the position of the set member, the malfunction of the acceleration sensor is prevented. Even if the hook is released, it is possible to prevent the ignition pin from colliding with the primer.

[0010]

However, even in the case of the malfunction prevention mechanism for preventing the inertial body and the ignition pin from moving as described above to prevent the malfunction of the starting device, the set for restraining the displacement of the ignition pin is also provided. There is a gap between the member and the locking portion of the ignition pin, and the ignition pin is movable in the direction of the primer by the gap between the set member and the ignition pin. Therefore, if an inadvertent impact acts on the assembly provided with such an activation device, and the hooking of the ignition pin by the trigger means is released, the ignition pin will remain in the gap until the locking portion contacts the set member. Just move. And since the ignition pin that has been locked by the trigger means cannot return to its original state by itself, when the malfunction prevention mechanism is released, the ignition pin whose trigger means has already come off collides with the primer and ignites the primer Let me do it. Therefore, in such a starting device, a mechanism for separately pushing back the ignition pin to a predetermined position is further required, and the structure becomes complicated, so that the number of parts increases, assemblability is not good, and the manufacturing cost is high. There is a problem.

An object of the present invention is to solve the above-mentioned problems, and to provide an activation device having an inexpensive malfunction prevention mechanism capable of reliably and easily preventing a malfunction of the activation device. That is.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to provide a starting device for striking a primer in response to an acceleration exceeding a predetermined value and for operating a gas generator, wherein a central axis extending toward the primer is provided.
Can be moved in the primer direction along
A, a firing pin that can ignite the detonator by colliding with detonator, columnar permanent magnet which can be moved into the detonator direction
The engaged portion with respect to the moving direction of the ignition pin.
From the side farther from the primer, the engaging portion engageable with the engaged portion.
And one of N and S poles is formed on the side near the primer
Is, possess an inertia member on the far side to the detonator other pole is formed, an inner diameter larger than the outer diameter of the inertial body, the ignition pin
Is located between the inertial body and the primer in the moving direction of the
One of the above poles is formed on the side close to the
An annular permanent magnet in which the other pole is formed on the other side ,
The ignition pin, the inertial body, and the annular permanent magnet are internally provided.
To the direction of inertia movement of the trigger case
The bottom of the cutout of the shaft is inserted through the hole provided
Interferes with the primer end of the inertial body and moves the
And a predetermined angle from that position to interfere with the inertial body
The inertial body can be selectively turned between
Moveable shaft and the ignition pin on the side remote from the primer.
At the rear end of the inertial body, and
Contact makes the ignition pin relative to the inertial body
And a movement prevention unit for preventing movement in the direction of the primer . or,
An object of the present invention is to provide a detonator in response to an acceleration exceeding a predetermined value.
And actuating the gas generator,
It is possible to move in the direction of the primer along the center axis facing the primer
Has a part to be engaged and collides with a primer.
The ignition pin is capable of igniting the primer and can be moved in the direction of the primer.
Of the ignition pin
The engaged portion from the side farther from the primer in the engaged portion.
N / S pole near the primer
One pole is formed, and the other pole is
Is larger than the outer diameter of the inertial body
It has an inside diameter, and the inertial body and the lightning
Placed between the tube and the side close to the inertial body
A pole is formed, and the other pole is formed on the side closer to the primer.
An annular permanent magnet, the ignition pin and the inertial body
Inertia body of trigger case with internal ring permanent magnet
Penetrates a hole with a polygonal cross-section
The shaft interferes with the primer end of the inertial body and
And the position in which the
Moves and interferes with the inertial body due to the notch formed in the middle part
Selectable between the position where the inertial body can be moved without
A movable shaft and ignition farther from the primer
At the rear end of the pin, at the end of the inertia body far from the primer
The contact between the ignition pin and the inertial body
And a movement prevention unit for preventing movement in the direction of the primer.
This is achieved by an activation device characterized by having.

Preferably, the inertial body and the ignition pin
And the inertia body have an ignition pin
Is provided, and the movement preventing portion is
The ignition pin is provided at the rear end of the ignition pin that has passed through the through hole.
You. Also, preferably, the movement preventing portion is configured to penetrate an inertial body.
It is a nut attached to the rear end part which penetrated the hole. More preferably, the activation device is used in a seat belt tightening device that is driven by gas pressure to rotate a winding shaft of a retractor in a seat belt retracting direction at the time of a vehicle collision.

[0014]

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.
The impact member can directly apply the impact energy to the primer by engaging with the trigger member, and the biasing member for releasing the restriction of the movement of the ignition pin in accordance with the movement of the inertial body and the bias shaft for biasing the ignition pin toward the primer. And the ignition pin can be prevented from moving in the direction of the squib only by preventing the inertial body from moving in the squib direction, so that a malfunction of the starting device can be prevented with a simple structure.

Further, when the inertial body is prevented from moving by the shaft , the inertia is limited by a gap generated between the shaft for restricting the movement of the inertial body due to an inadvertent impact and the engaging portion of the inertial body. Even if the body moves in the direction of the primer, the inertial body is pushed back to a predetermined position by the repulsive force of the magnetic force on the ring-shaped permanent magnet, and as soon as the shaft is released in order to make the inertial body movable, the ignition pin is turned on. Never ignite.

[0016]

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

The retractor 1 with a pretensioner has a retractor base 18 formed in a substantially U-shape on one side wall of the retractor base 18 so that the take-up shaft can be moved in the direction in which the slack of the seat belt is removed in the event of a vehicle collision. A pretensioner 3, which is a seat belt tightening device to be rotated, is provided. The retractor 1 with a pretensioner is mounted on a vehicle body panel as an assembly in which the pretensioner 3 is previously assembled integrally with the retractor.

The pretensioner 3 applies a tension to a wire 7 which is a transmission member wound around a pulley (not shown) which is attached to one end of a winding shaft, for example.
Draws and drives the take-up shaft in the webbing take-up direction to draw in the emergency state of the webbing 16 that has been hung over the occupant. The drive means 4 for applying tension to the wire 7 and the vehicle collision And a starter 21 for operating the drive means 4 by detecting the

The driving means 4 includes a piston 6 connected to one end of a wire 7, a cylinder 5 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 an activation device 21 that activates the gas generator 8 in response to a predetermined acceleration or more. The housing 15 is
It is a substantially L-shaped tube member bent at a substantially right angle, and the base end of the cylinder 5 is fixed to one opening 19 thereof.
The hole 6 provided opposite the opening 19 has a piston 6
Is inserted through the wire 7.

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. 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. Therefore, the gas generator 8
An activation device 21 for striking the primer 10 is fixed to the side of the primer 10 with the side wall of the retractor base 18 interposed therebetween.

The starting device 21 is, as shown in FIG.
Center made of non-magnetic material such as stainless steel and facing the primer
It can be moved along the axis in the direction of the primer (leftward in the figure).
And a flange portion 22b as an engaged portion.
The ignition pin 22 is capable of igniting the primer 10 by colliding with the ignition pin 10 and the ignition pin 22 is movable in the direction of the primer.
The Ri Do a cylindrical permanent magnet provided with a through hole 23a which loosely fitted is along the central axis, the moving direction of said ignition pin 22
The flange 2b from the side of the flange 22b farther from the primer.
2b, which has a primer-side end 23b which is an engagement portion engageable with the
An N pole is formed on the side close to the primer 10, and an S pole is formed on the other side.
An inertial body 23 formed to have a larger inner diameter than the outer diameter of the inertial body 23, regarding the movement direction of the ignition pin 22
The inertial body 23 is disposed between the inertial body 23 and the primer 10.
The N pole is formed on the side close to
An annular permanent magnet 24 having poles formed therein, a trigger case 25 internally provided with the magnet and fixed to a side wall of the retractor base 18, and a malfunction of the activation device 21 provided in the trigger case 25. And a malfunction prevention mechanism 9 for preventing the malfunction. Therefore, the inertial body 23 and the ignition pin 22
It is configured coaxially.

The ignition pin 22 is located on the side near the primer 10.
A firing pin 22a for hitting the primer 10 is formed at a certain tip , and a rear end remote from the primer 10 is a trigger.
-Inserted slidably into the bottom wall 25c of the case 25,
The flange portion 22 b is formed between the end portions, and is provided inside the trigger case 25. At this time, the ignition pin 22
A nut 22c as a movement preventing portion attached to a rear end portion of the inertial body 23 penetrating the through hole 23a abuts on a bottom wall side end of the inertial body 23 (an end of the inertial body far from the primer) . Movement in the direction of the primer relative to the inertial body 23 is prevented, and in the initial state, movement to the primer side is restricted. Note that a caulking member or the like may be permanently fixed to the ignition pin 22 instead of the nut 22c.

Therefore, the firing pin 22a passes through the opening 25b formed in the wall 25a of the trigger case 25 on the primer side to face the primer 10 with a gap, and the flange 22b
Are opposed to the inner wall surface of the wall 25a with a gap. Therefore, when the inertial body 23 collides with the flange 22b,
The ignition pin 22 moves to the primer side, and the firing pin 22a
To strike and ignite.

The annular permanent magnet 24 is fitted inside the primer case of the trigger case 25, and the inertial body 23 penetrated by the ignition pin 22 is mounted on the bottom wall side of the trigger case 25. ing. Therefore, the primer side end 23b is spaced from the bottom wall side end 24a of the annular permanent magnet 24, and the adjacent magnetic poles are arranged so as to have the same pole (N pole-N pole in the figure). The inertial body 23 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 slidable in the axial direction along the ignition pin 22, but has a primer size larger than the repulsive force of the magnetic force acting between the annular permanent magnet 24 and the inertial body 23. If no directional force acts on the inertial body 23, the inertial body 2
Since 3 cannot move in the direction of the primer, the activation device 21 does not operate.

When the malfunction prevention mechanism 9 to be described later is released and the shaft 31 does not interfere with the inertial body 23, the inertial force of the inertial body obtained by multiplying the weight of the inertial body 23 and the acceleration in the priming direction becomes a magnetic force. Is greater than the repulsion of
As shown in FIG. 5A, the inertial body 23 moves in the direction of the primer (leftward in the figure). Further, when the inertial body 23 moves to a region where a magnetic attraction force acts on the inertial body 23, the inertial body 23
Is accelerated in the direction of the primer by the magnetic attraction, and Fig. 5 (b)
As shown in (1), it is inserted into the opening of the annular permanent magnet 24 and collides with the flange 22b. As described above, the inertial body 23 has a function as an acceleration sensor by utilizing the fact that the magnetic force changes to repulsion-attraction, and a function as a trigger means for starting the supply of impact energy to the ignition pin 22. In general, the ignition pin 22 itself also starts moving due to acceleration in the primer direction, so that the inertial body 23 and the flange 22b do not always come into contact with each other at the position shown in FIG.

Further, the inertial body 23 accelerated in the direction of the primer by the attraction of the magnetic force moves the ignition pin 22 in the direction of the primer as shown in FIG.
Hit and fire with a. In general, the priming device 10 is not moved until the flange 22b of the ignition pin 22 comes into contact with the inner wall surface of the wall portion 25a.
Is set to fire. Starting device 21
Is provided with a malfunction prevention mechanism 9 for preventing the activation device 21 from malfunctioning before the retractor 1 with the pretensioner is assembled to the vehicle as an assembly.

The malfunction prevention mechanism 9 includes a bottom wall side end 24a of the annular permanent magnet 24 and a primer side end 23b of the inertial body 23.
And a shaft which is inserted through a hole 25d provided so as to cross the upper part of the guide hole of the trigger case 25, and selectively brings the inertial body 23 into the movement preventing state and the movable state. Has a shaft 31 made of a non-magnetic material. As shown in FIG. 3, one end of the shaft 31 is expanded so that the shaft 31 is prevented from falling out of the trigger case 25, a compression coil spring 32 is wound around the shaft 31, and a spring pin 33 is fixed to the other end by press-fitting. Yes,
By operating the spring pin 33 as described later, it is possible to rotate within a predetermined range. The intermediate portion of the shaft 31 corresponding to the guide hole of the trigger case 25 has a substantially semicircular cross section,
Notch 31a that can take a rotational phase that does not interfere with the configuration.

As shown in FIG.
At the peripheral end of the hole 25d on the side opposite to the third side, recesses 25e are formed at equal intervals in a pair so as to fit the spring pins 33 and arranged orthogonally to each other. The spring pin 33 is held in the desired pair of recesses 25e by the urging force of the spring 32. Therefore,
The shaft 31 is moved in the axial direction against the urging force of the compression coil spring 32, and once disengaged from the recess 25e, the spring pin 33 is rotated to rotate the other pair of recesses 25e.
, The shaft 31 can be held with a rotation phase difference of about 90 degrees. The means for fixing the rotation direction of the shaft 31 is not limited to the spring pin 33 and the concave portion 25e as described above, but may be, for example, a rotation limiter and a snap action spring.

Therefore, when the malfunction preventing mechanism 9 is set, the spring pin 33 is at a position as shown in FIG. 4, and the bottom of the notch 31a of the shaft 31 is It faces the upper part of the side end 23b. Then, the inertial body 23 and the shaft 31 interfere with each other, so that the inertial body 23 is prevented from moving in the direction of the squib, and the nut 22c attached to the rear end portion of the inertial body 23 is on the bottom wall side of the inertial body 23. Ignition pin 22 in contact with the end
Also, the starting device 21 cannot operate (see FIGS. 2 and 3) because it cannot move in the direction of the primer relative to the inertial body 23.

That is, at the time of a vehicle collision,
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 trigger shaft for releasing the movement restriction of the ignition pin 22 according to the movement of the inertial body 23 and the biasing of the ignition pin 22 toward the primer are provided. Since the biasing member is not required and the ignition pin 22 is also prevented from moving in the direction of the primer by simply preventing the inertial body 23 from moving in the direction of the primer, the malfunction of the activation device 21 can be prevented with a simple structure. .

Next, when the retractor 1 with the pretensioner is mounted on the vehicle and the malfunction preventing mechanism 9 is released, the shaft 31 is moved in the axial direction against the urging force of the compression coil spring 32. After that, the spring pin 33 is rotated about 90 degrees in the direction of arrow Y, and fitted into the other pair of recesses 25e as indicated by the imaginary line. Then, the shaft 31 is also rotated about 90 degrees in the direction of arrow Y, and the notch 31a is located at a position where it does not interfere with the inertial body 23 as shown in FIG. The starting device 21 is in an operable state.

When the malfunction prevention mechanism 9 is set and the activation device 21 is inoperable, the gap between the bottom surface of the notch 31a and the primer end 23b due to dimensional tolerance is provided. However, even if the inertial body 23 is moved in the direction of the primer by the gap due to an inadvertent impact, the inertial body 23 is moved toward the bottom wall away from the primer 10 by the repulsive force of the magnetic force on the annular permanent magnet 24. Since it is pushed back, the ignition pin 22 does not move in the direction of the primer 10 and ignite the primer 10 as soon as the malfunction prevention mechanism 9 is released to make the inertial body 23 movable. . Therefore, the malfunction prevention mechanism 9 can reliably prevent the malfunction of the activation device 21 in any situation, and does not require a mechanism for pushing the ignition pin 22 back to a predetermined position.

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 becomes 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.

FIG. 6 is a longitudinal sectional view of an activation device 41 according to another embodiment of the present invention, and FIG. 7 is a sectional view taken along the line BB in FIG. Note that the same components as those of the activation device 21 of the above embodiment are denoted by the same reference numerals, and description thereof will be omitted. Malfunction prevention mechanism 4 of activation device 41 in the present embodiment
An octagonal cross section 2 is provided between the bottom wall side end 24a of the annular permanent magnet 24 and the primer side end 23b of the inertial body 23 so as to cross the upper part of the guide hole of the trigger case 25. It has a shaft 43 having an octagonal cross section, which is a shaft inserted through the hole 45 and selectively bringing the inertial body 23 into the movement preventing state and the movable state.

The shaft 43 is, as shown in FIG.
One end is enlarged to prevent the trigger case 25 from coming off, and the other end is provided with a snap action spring 44 having both ends supported, and is movable in a predetermined range in the axial direction. . In addition, a contact surface 43b facing the inertial body 23 is formed at an intermediate portion of the shaft 43 corresponding to the guide hole of the trigger case 25, and a circle for preventing interference with the inertial body 23. An arc-shaped notch 43a is formed.

When the malfunction preventing mechanism 42 is set, the shaft 43 is held in the position shown in FIG. 7 by the urging force of the snap action spring 44, and the contact surface 43b of the shaft 43 is
Faces the upper portion of the primer side end 23b of the inertial body 23.
Then, the inertial body 23 and the shaft 43 interfere with each other, so that the inertial body 23 is prevented from moving in the direction of the squib, and the nut 22c mounted on the rear end portion is moved toward the bottom wall of the inertial body 23. The ignition pin 22 abutting on the end is also connected to the inertia body 2.
The starting device 21 cannot be operated because it cannot move in the direction of the primer relative to 3.

Next, when releasing the malfunction prevention mechanism 42, the shaft 43 is moved in the axial direction (left direction in the figure) against the urging force of the snap action spring 44. Then, the biasing direction of the snap action spring 44 is reversed, and the shaft 43 is biased leftward in the drawing, and the enlarged diameter portion is held at a position where it contacts the trigger case 25. At this time, since the notch 43a corresponds to the guide hole of the trigger case 25 and is located at a position where it does not interfere with the inertial body 23, the inertial body 23 is in a movable state capable of moving in the direction of the primer, and the starting device 21 is in an operable state. The shaft 43 and the hole 45 are formed to have an octagonal cross section. However, since the shaft 43 and the hole 45 only need to have a cross section that cannot rotate around the axis, other shapes such as a polygon and a semicircle may be used. Can be adopted.

The members constituting the starting device according to the present invention are not limited to the shapes in the above embodiments.
It goes without saying that various forms can be adopted on the basis of the gist of the present invention, and the respective structures of the activation device and the pretensioner can be appropriately changed. For example, in the above embodiments, although the movement preventing state and a movable state inertial body by manipulating the sheet Yafuto malfunction preventing mechanism directly connecting the interlocking means such as a link mechanism or wire operating member it makes it possible to perform these switching Te to the operation member installed in easy location spear operation.

In each of the above embodiments, the inertial body 2
The inertial body 23 that moves in the direction of the primer faster than the ignition pin 22 collides against the flange 22b of the ignition pin 22 that is prevented from moving in the direction of the primer relative to the primer 3.
By firing, the amount of movement of the inertial body 23 is increased and a speed sufficient to ignite the detonator 10 is obtained in a space-saving manner. However, the ignition pin may be fixed to the inertial body and integrated. It is possible.

Further, 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. The same applies to actuating actuating devices.

[0043]

According to the starting device of the present invention, when an inertial body composed of a columnar permanent magnet is subjected to a predetermined acceleration or more in the direction of the primer, the inertial body reduces the repulsive force of the magnetic force on the annular permanent magnet. The inertial body itself directly imparts impact energy to the primer since the ignition pin moves in the direction of the primer in the opening of the annular permanent magnet in opposition, and furthermore, the ignition pin is moved in the direction of the primer with the attraction of magnetic force. Therefore, there is no need for a trigger shaft for releasing the restriction on the movement of the ignition pin in accordance with the movement of the inertial body, and an urging member for urging the ignition pin toward the primer.

Further, when the inertial body is prevented from moving by the shaft , the inertia is limited by a gap generated between the shaft for restricting the movement of the inertial body due to an inadvertent impact and the engaging portion of the inertial body. Even if the body moves in the direction of the primer, the inertial body is pushed back to a predetermined position by the repulsive force of the magnetic force on the ring-shaped permanent magnet, and as soon as the shaft is released in order to make the inertial body movable, the ignition pin is turned on. Never ignite. So, in any situation,
A malfunction of the activation device can be reliably prevented, and a mechanism for pushing the ignition pin back to a predetermined position is not required, and the structure is not complicated.

Accordingly, it is possible to provide a starting device having an inexpensive malfunction preventing mechanism capable of reliably and easily preventing a malfunction of the starting device.

[Brief description of the drawings]

FIG. 1 is a partial front view of a retractor with a pretensioner provided with a starting device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of the activation device shown in FIG.

FIG. 3 is a sectional view of the activation device shown in FIG.

FIG. 4 is a front view of the activation device shown in FIG. 2;

FIG. 5 is a longitudinal sectional view for explaining an operation state of the activation device shown in FIG. 1;

FIG. 6 is a longitudinal sectional view of an activation device according to another embodiment of the present invention.

FIG. 7 is a sectional view of the activation device shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Retractor with pretensioner 3 Pretensioner 4 Driving means 5 Cylinder 9 Malfunction prevention mechanism 13 Emergency lock mechanism 16 Webbing 18 Retractor base 21 Starting device 22 Ignition pin 22a Shooting pin 22b Flange 22c Nut 23 Inertia body 24 Toroidal permanent magnet 25 Trigger case 31 Shaft

Claims (5)

(57) [Claims] 1. A starting device for striking a primer in response to a predetermined acceleration or more and operating a gas generator, wherein the starting device is movable in the direction of the primer along a central axis line facing the primer.
Is has the engaged portion with which the ignition pin can be ignited the detonator by colliding with detonator consists columnar permanent magnet which can be moved into the detonator 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;
One of the N and S poles is formed on the side closer to
An inertial body other pole is formed on the far side, the have a larger inner diameter than the outer diameter of the inertial body, the ignition pin
The inertial body is located between the inertial body and the primer in the direction of movement.
One of the above poles is formed on the side close to
An annular permanent magnet having the other pole formed therein , the ignition pin, the inertial body, and the annular permanent magnet being internally provided.
To the direction of inertia movement of the trigger case
The bottom of the cutout of the shaft is inserted through the hole provided
Interferes with the primer end of the inertial body and moves the
And a predetermined angle from that position to interfere with the inertial body
The inertial body can be selectively turned between
A movable shaft and a rear end of the ignition pin far from the primer,
Ignited by contacting the end of the body farther from the primer
The pin moves toward the primer relative to the inertial body.
An activation device , comprising: a movement blocking unit that blocks movement . 2. A primer is struck in response to an acceleration exceeding a predetermined value.
And a starter for actuating the gas generator, which can be moved in the direction of the primer along the central axis facing the direction of the primer.
Has a part to be engaged and collides with a primer.
An ignition pin capable of igniting the primer, and a columnar permanent magnet movable toward the primer.
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;
One of the N and S poles is formed on the side closer to
An inertial body in which the other pole is formed on the far side, and an inner diameter larger than the outer diameter of the inertial body,
The inertial body is located between the inertial body and the primer in the direction of movement.
One of the above poles is formed on the side close to
An annular permanent magnet having the other pole formed therein, the ignition pin, the inertial body, and the annular permanent magnet being internally provided.
To the direction of inertia movement of the trigger case
The shaft is inertial through the provided polygonal cross section hole
The position where the inertial body is prevented from moving by interfering with the primer end of the body
And moved in the axial direction from the position, formed in the middle part
Notch allows the inertial body to move without interfering with the inertial body
Shaft that can be selectively moved between and
At the rear end of the ignition pin far from the primer,
Ignited by contacting the end of the body farther from the primer
The pin moves toward the primer relative to the inertial body.
An activation device , comprising: a movement blocking unit that blocks movement . 3. The apparatus according to claim 2, wherein said inertia body and said ignition pin are coaxial.
In addition to the configuration, the inertia body has a penetration through the ignition pin
A hole is provided, and the movement preventing portion penetrates the through hole.
The ignition pin is provided at the rear end of the ignition pin.
An activation device as described. 4. The movement preventing portion penetrates a through hole of an inertial body.
The nut according to claim 3, wherein the nut is a nut attached to a rear end portion through which the nut passes.
Motion device. 5. A retractor driven by gas pressure.
The take-up shaft in the seat belt retracting direction in the event of a vehicle collision.
Used for a seat belt tightening device that rotates
In response to the acceleration of the gas, the primer was struck and the gas generator was activated.
The activation device according to claim 1 or 2, wherein the activation device is activated.