JP2590492Y2 - Mechanical ignition type sensor - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical ignition sensor for detecting a sudden deceleration state of a vehicle.

[0002]

2. Description of the Related Art For example, in a seat belt device mounted on a vehicle, a webbing mounted on an occupant is pulled back by a predetermined amount when the vehicle is suddenly decelerated, the slack of the webbing for the occupant is forcibly removed, and the webbing is tensioned to occupy the occupant. Some include a so-called pretensioner with improved restraint.

In this type of pretensioner, there is a pretensioner configured to forcibly rotate a winding shaft of a webbing take-up device to tension the webbing, or a configuration configured to forcibly pull a buckle to tension the webbing. However, in a configuration in which the webbing is tensioned by, for example, pulling a buckle, a gas generator provided with a mechanical ignition type sensor is provided. The gas generator is provided with a cylinder, which is connected to a buckle via a wire or the like.

When the vehicle reaches a sudden deceleration state, this is detected by a mechanical ignition type sensor and a gas generator is activated, gas is instantaneously generated and the cylinder is moved, and this moving force is transmitted to the buckle via a wire. Then, the buckle is forcibly moved to tension the webbing.

[0005]

The mechanical ignition type sensor used in such a conventional pretensioner basically includes an ignition pin for igniting a detonator, an inertial body which inertially moves by a large acceleration, and Although a trigger member such as a ball is interposed between the ignition pin and the inertial body to prevent the movement of the ignition pin (for example, Japanese Patent Publication No. 52-13104, etc.), the trigger member is merely an inertia member. In the normal state, the trigger pin was interposed between the body and the ignition pin to prevent the movement of the ignition pin. Therefore, the trigger member was once separated from between the inertial body and the ignition pin, and the movement stop state of the ignition pin was released. Later, it was extremely difficult to reset the ignition pin to a state in which the movement of the ignition pin was prevented again.

Therefore, for example, when the operation sensitivity of a mechanical ignition type sensor is checked and an operation test is performed to determine whether or not the operation is surely performed, even if the operation test itself can be performed, the gas test is thereafter performed properly. Since it cannot be put into an operable state (reset) by assembling it with a generator, a countermeasure for this has been desired. In this case, the operation inspection of the mechanical ignition sensor cannot be omitted.

In consideration of the above facts, the present invention is a mechanical ignition type which can be easily reset even after performing an operation test for confirming sensitivity and the like with a simple structure without hindering stable operation. The purpose is to get a sensor.

[0008]

A mechanical ignition type sensor according to the present invention is arranged so as to be movable in an axial direction, and is moved in an axial direction by an urging force of a firing spring to ignite a detonator. An ignition pin, an inertial mass that is always urged by a bias spring, and moves by an inertial force against an urging force of the bias spring when a predetermined load is applied, and the ignition by a spindle between the ignition pin and the inertial mass. An engaging portion rotatably supported in the direction of coming into contact with and separating from the pin and engaging with the ignition pin; and a pressing member formed on a side opposite to the engaging portion with respect to the support shaft and capable of engaging with the ignition pin. A projection, and the engaging portion is normally engaged with the ignition pin and is pressed by the inertial mass body so as to be prevented from rotating around the support shaft. Yo The ignition pin is held at a position separated from the detonator against the urging force of the firing spring while being pressed in a direction away from the ignition pin, and the inertial mass is moved when the inertial mass is moved. The rotation stop is released, and the rotation of the ignition pin is enabled by the rotation in the direction away from the ignition pin, and the pressing protrusion enters the movement locus of the ignition pin and can be engaged with the ignition pin. And a trigger lever.

[0009]

In the mechanical ignition sensor according to the first aspect of the present invention, the ignition pin is usually located at a position separated from the primer by resisting the urging force of the firing spring, and the inertial mass body is rotated by the bias spring by the trigger spring. When the trigger lever is rotated in the direction approaching the ignition pin, the engagement portion engages with and holds the ignition pin, and the rotation is prevented by the inertial mass body and the trigger lever is ignited. The pin holding state is maintained.

When a large acceleration acts on the mechanical ignition sensor, the inertial mass moves by inertia and separates from the rotation locus of the trigger lever. Thereby, the holding of the trigger lever by the inertial mass body is released, and the rotation of the trigger lever around the support shaft becomes possible. For this reason, the trigger lever pressed in the direction away from the ignition pin by the ignition pin urged by the firing spring rotates in the direction away from the ignition pin. As a result, the holding of the ignition pin by the engagement portion of the trigger lever is released, and the ignition pin moves in the axial direction by the urging force of the firing spring, and ignites the primer.

Further, in the moving state of the ignition pin, the pressing projection of the trigger lever has entered the movement locus of the ignition pin, and is in a state capable of engaging with the ignition pin.

Next, when the mechanical ignition type sensor which has been operated once is brought into an operable state again (reset), the ignition pin is moved in the axial direction against the urging force of the firing spring.

Here, when the trigger lever is moved in the axial direction, the pressing projection of the trigger lever which has entered the movement locus of the ignition pin is pressed by the ignition pin. As a result, the trigger lever rotates in a direction approaching the ignition pin, and when the ignition pin reaches the initial position, the engaging portion is engaged with the ignition pin again, and at the initial position where the ignition pin is separated from the primer. Hold. Further, with the rotation of the trigger lever, the inertial mass body enters the rotation trajectory of the trigger lever again by the bias spring and the rotation of the trigger lever is prevented, and the ignition pin is held.

Thus, the trigger lever can be rotated to return to the initial state of holding the ignition pin simply by moving the ignition pin to the initial position along the axis. Therefore, for example, after performing the operation inspection of the mechanical ignition type sensor, it is also possible to easily assemble it into the gas generator and bring it into an operable state (reset).

[0015]

1 and 2 are sectional views of a mechanical ignition type sensor 10 according to an embodiment of the present invention.

The mechanical ignition type sensor 10 has a case 12. The case 12 is formed in a cylindrical shape having a bottom wall 14 at one end, and a plate 16 is fixed and sealed on the opening side. A through hole 18 is formed on the bottom wall 14 of the case 12 on the axis, and a substantially cylindrical guide 20 is formed on the bottom wall 14 coaxially and protruding inward of the case 12. .

An ignition pin 22 is arranged inside the case 12. The ignition pin 22 includes a substantially cylindrical main body 24 and a projection 26 integrally formed from a bottom wall 24A of the main body 24. Body 2
The outer diameter of the main body 4 corresponds to the inner diameter of the guide 20, and the main body 2 is slid in the case 12 along the axis.
4 can enter the guide 20. On the other hand, convex part 2
6 projects outward from the through hole 18 formed in the bottom wall 14 in a state where the ignition pin 22 (main body 24) is moved to the bottom wall 14 side of the case 12 most.

A firing spring 28 is disposed between the ignition pin 22 and the plate 16 and always urges the ignition pin 22 toward the through hole 18.

On the other hand, around the guide 20, an inertial mass body 30 is arranged. The inertial mass body 30 is formed in a substantially cylindrical shape, and is movably housed between the peripheral wall of the case 12 and the guide 20. A bias spring 32 is disposed between the inertial mass 30 and the plate 16, and always biases the inertial mass 30 toward the bottom wall 14.

A pair of trigger levers 34 is disposed between the inertial mass 30 and the ignition pin 22. One end of the trigger lever 34 is rotatably supported by a shaft 36. Further, the tip of the trigger lever 34 is bent toward the ignition pin 22 to form an engaging portion 38,
It can be engaged with the ignition pin 22. That is, when the trigger lever 34 rotates around the shaft 36, the engagement portion 38
Can approach or separate from the ignition pin 22. When the engagement portion 38 of the trigger lever 34 is engaged with the main body 24 of the ignition pin 22, the ignition pin 22 urged by the firing spring 28 is moved to a position where the projection 26 is pulled out of the through hole 18. keeping.

A slide holding portion 40 is formed so as to protrude toward the inertial mass body 30 on the opposite side of the ignition pin 22 at the longitudinal middle portion of the trigger lever 34. The slide holding section 40 corresponds to the slide section 31 formed on the inertial mass body 30 and is configured to linearly contact the slide section 31. That is, usually, the inertial mass 3
Reference numeral 0 denotes a position closest to the bottom wall 14 of the case 12 by the bias spring 32. In this state, the slide portion 31 of the inertial mass body 30 is in contact with the slide holding portion 40 of the trigger lever 34, and the trigger lever 34 Are engaged with the main body 24 of the ignition pin 22, and the ignition pin 22 is held at a position where the projection 26 is pulled out of the through hole 18. Further, when the inertial mass 30 moves in a direction away from the bottom wall 14, the inertial mass 3
The zero slide portion 31 is configured to relatively move while linearly contacting the slide holding portion 40 of the trigger lever 34.

Further, a pressing projection 41 is formed at the rear end of the trigger lever 34 (the end opposite to the engagement portion 38) so as to project toward the ignition pin 22. This pressing projection 41
In the state where the trigger lever 34 is rotated and the holding of the ignition pin 22 by the engagement portion 38 is released, the ignition pin 22
Are set in such a manner as to enter into the movement locus of the ignition pin 22 and to be engaged with the rear end of the ignition pin 22. Thus, the pressing projection 41 can be pressed by the rear end of the ignition pin 22 by sliding the ignition pin 22 away from the through hole 18.

The mechanical ignition sensor 10 having the above configuration
Is mounted on a gas generator (not shown) for a pretensioner, for example. The gas generator contains a gas generating agent, and further includes a squib 42 for igniting and burning the gas generating agent. Detonator 42
Are located on the axis of the mechanical ignition sensor 10 when the mechanical ignition sensor 10 is assembled. Therefore, in this assembled state, the through hole 18 of the case 12 faces the primer 42, and the projection 26 of the ignition pin 22 that can protrude from the through hole 18 can collide with the primer 42.

Next, the operation of this embodiment will be described. In the mechanical ignition sensor 10 of the present embodiment configured as described above,
Normally, as shown in FIG. 1, the ignition pin 22 is located at a position separated from the primer 42 (a position pulled out from the through hole 18 of the case 12) against the urging force of the firing spring 28, and the trigger lever 34 is The engaging portion 38 is engaged with the main body 24 of the ignition pin 22 and holds the ignition pin 22. Further, the inertial mass body 30 is moved to the position closest to the bottom wall 14 by the bias spring 32, that is, the trigger lever 34.
The slide portion 31 abuts the slide holding portion 40 of the trigger lever 34 to prevent the rotation of the trigger lever 34 and maintain the ignition pin holding state.

Here, when a large acceleration acts on the mechanical ignition type sensor 10, the inertial mass body 30 inertially moves in the direction of arrow A in FIG. 1 and separates from the rotation locus of the trigger lever 34.

In this case, the inertial mass body 30 (slide portion 3
1) moves while being in linear contact with the slide holding portion 40 of the trigger lever 34. When the slide holding portion 40 of the trigger lever 34 is separated from the slide portion 31 of the inertial mass body 30 and the holding thereof is released, the shaft 3 of the trigger lever 34 is released.
The rotation around 6 becomes possible. Therefore, the trigger lever 34 pressed by the ignition pin 22 urged by the firing spring 28 in the direction away from the ignition pin 22 is rotated in the direction away from the ignition pin 22. As a result, the engaging portion 38 of the trigger lever 34 is separated from the main body 24 of the ignition pin 22 to release the holding of the ignition pin 22, so that the ignition pin 22 moves in the axial direction by the urging force of the firing spring 28. Then, the protrusion 26 protrudes outward from the through hole 18 (the state shown in FIG. 2).

As a result, the projection 26 of the ignition pin 22 collides with the primer 42 and the primer 42 is ignited. When the primer 42 is ignited, the gas generating agent of the gas generator is ignited and burned, and, for example, a pretensioner is operated.

Here, when the mechanical ignition type sensor 10 operates, that is, when the inertial mass body 30 moves, the slide portion 31 moves while being in linear contact with the slide holding portion 40 of the trigger lever 34. , The trigger lever 34 (slide holding section 40) and the inertial mass body 30 (slide section 3).
The friction force between 1) is constant and does not fluctuate. In other words, the direction in which the ignition pin 22 presses the trigger lever 34 and the direction in which the trigger lever 34 presses the inertial mass 30 do not change or change as in the related art as the inertial mass 30 moves. Therefore, the trigger lever 34
The frictional force between the (slide holding section 40) and the inertial mass body 30 (slide section 31) does not greatly change with the movement of the inertial mass body 30, and the operation sensitivity of the mechanical ignition sensor 10 is stable. I do.

Further, the trigger lever 34 has its shaft 36
If the lever ratio between the shaft 36 and the engaging portion 38 is suitably set between the trigger lever 34 (slide holding portion 40) and the inertial mass body 30 (slide portion 31). It is also possible to easily reduce the frictional force acting between them, which is more effective.

In the mechanical ignition type sensor 10, each pressing force acting on the trigger lever 34 is applied to the inertial mass 30.
Does not balance during the movement of the inertia mass body 30 and the trigger lever 3 if a predetermined inertia force acts.
4 is also prevented from stopping halfway.

Once the mechanical ignition sensor 10 has been activated and the ignition pin 22 has moved, the pressing projection 41 of the trigger lever 34 has entered the movement locus of the ignition pin 22;
The rear end portion of the ignition pin 22 can be engaged with the rear end portion.

Next, the mechanical ignition type sensor 1 once activated
In the case where 0 is made operable again (reset), it can be reset by moving the ignition pin 22 in the axial direction against the urging force of the firing spring 28.

That is, the ignition pin 22 in a state where the projection 26 protrudes from the through hole 18 is pressed from the outside of the case 12 using a jig or the like, and is moved toward the plate 16.

Here, the trigger lever 34 is
, The pressing projection 41 of the trigger lever 34 that has entered the movement locus of the ignition pin 22 is pressed by the ignition pin 22. As a result, the trigger lever 34
The engaging portion 38 is rotated around the shaft 36 in a direction approaching the ignition pin 22, and when the ignition pin 22 reaches the initial position, the engaging portion 38 is again turned on the ignition pin 22 (the bottom wall 24 </ b> A of the main body 24).
And holds the ignition pin 22 in the initial position separated from the primer 42. Further, with the rotation of the trigger lever 34, the inertial mass body 30 again enters the rotation locus of the trigger lever 34 by the bias spring 32, and the trigger lever 3
4 is prevented from rotating, and the ignition pin is held.

As described above, in the mechanical ignition type sensor 10,
Not only is it possible to reduce the adverse effect of the frictional force between the trigger lever 34 and the inertial mass body 30 to ensure stable operability, but also to simply press the ignition pin 22 from the outside to move it to the initial position. The lever 34 can be rotated to return to the initial state in which the ignition pin 22 is held. Therefore, for example, even if the operation test is performed before the mechanical ignition type sensor 10 is mounted on the gas generator, it is also easy to properly mount the sensor on the gas generator to make it operable (reset) thereafter. it can.

In the mechanical ignition sensor 10 in the above embodiment, the ignition pin 22 is held by the pair of trigger levers 34. However, the number of the trigger levers 34 is not limited to this. Three or more may be provided.

The mechanical ignition sensor 10 in the above embodiment is used for a gas generator for a pretensioner. However, the present invention is not limited to this. It is possible.

[0038]

As described above, the mechanical ignition type sensor according to the present invention has a simple structure without impairing the stable operability and can be easily operated even after performing the operation inspection for confirming the sensitivity and the like. It has an excellent effect that resetting is possible.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an initial state of a mechanical ignition sensor according to the present invention.

FIG. 2 is a cross-sectional view showing a state after the mechanical ignition sensor according to the present invention is operated.

[Explanation of symbols]

 Reference Signs List 10 mechanical ignition type sensor 22 ignition pin 28 firing spring 30 inertial mass body 32 bias spring 34 trigger lever 38 engaging portion 41 pressing projection 42 detonator

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-8701 (JP, A) JP-A-3-45354 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01P 15/00 B60R 22/46

Claims (1)

(57) [Scope of request for utility model registration] Claims: 1. An axially movable arrangement, wherein:
An ignition pin that moves in the axial direction by the biasing force of the firing spring to ignite the detonator; And an engaging portion rotatably supported by a support shaft between the ignition pin and the inertial mass body in a direction approaching and separating from the ignition pin, and engaging with the ignition pin; A pressing projection formed on the opposite side to the mating portion and capable of engaging with the ignition pin; usually, the engagement portion engages with the ignition pin and is pressed by the inertial mass body so that the support shaft is The rotation of the surroundings is stopped, and the urging force of the firing spring is applied to the ignition pin while being pressed by the ignition pin in a direction away from the ignition pin. The inertial mass body is held at a position away from the primer, and when the inertial mass body is moved, the rotation inhibition by the inertial mass body is released, and the inertial mass body is rotated in a direction away from the ignition pin to be able to move the ignition pin. And a trigger lever, wherein the pressing protrusion enters the movement locus of the ignition pin and is brought into a state capable of engaging with the ignition pin.