JP3431344B2 - Mechanical ignition type sensor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical ignition sensor used for an occupant protection device such as an airbag device and a pretensioner device. 2. Description of the Related Art Conventionally, as one of occupant protection devices mounted on a vehicle, there is an airbag device for inflating a bag toward the occupant when the vehicle is suddenly decelerated. There are various types of airbag devices. For example, in a mechanical ignition type airbag device, an inflator having a gas generating agent or the like therein, a base plate on which the inflator is mounted, and a folded state mounted on the base plate. The bag comprises a bag, a pad which is stored between the bag and the base plate, and which breaks and expands when the vehicle is suddenly decelerated. Furthermore, in a mechanical ignition type airbag device, the sensor itself is arranged on the shaft core of the inflator. This mechanical ignition type sensor basically has an ignition pin for igniting a detonator, an inertial mass body that inertially moves by a large acceleration, and a movement of the ignition pin interposed between the ignition pin and the inertial mass body. When the vehicle suddenly decelerates, the inertial mass moves by inertia and the ignition pin is released from being held by the trigger lever, and the ignition pin pierces the primer with the biasing force, thereby generating gas. In this configuration, the agent burns. The mechanical ignition sensor as described above has a sensor operation sensitivity set so as to operate reliably when a predetermined acceleration is applied.
It is determined by various factors such as the mass of the inertial mass, the spring characteristics of the spring that biases the inertial mass and the ignition pin. In this case, of the various factors that determine the sensor operation sensitivity, in particular, a predetermined allowance (a so-called trigger stroke) between the inertial mass body that maintains the ignition pin holding state and the trigger lever depends on the inertial mass when a predetermined load is applied. This is the most important factor in the configuration in which the trigger lever is fitted into the trigger groove due to the inertial movement of the body beyond the hooking margin to release the ignition pin holding state and operate. For this reason, in a conventional mechanical ignition sensor,
In order to set the allowance (trigger stroke) between the inertial mass and the trigger lever to a predetermined dimension, each component of the sensor is manufactured with high precision, whereby the sensor operates reliably with a predetermined operation sensitivity. It is configured as follows. However, the mechanical ignition type sensor as described above is composed of an inertial mass, a trigger lever, or a large number of components such as a sensor main body (case) accommodating these components. The allowance (trigger stroke) is largely dependent on (affected by) the dimensions of many components. For this reason, in order to maintain the predetermined operation sensitivity, it is necessary to set strictly the dimensional tolerances of the components related to the hanging allowance, which is costly. SUMMARY OF THE INVENTION In view of the above facts, the present invention can set a large dimensional tolerance of each component while reliably maintaining a predetermined operation sensitivity, thereby reducing cost. The aim is to obtain a mechanically ignitable sensor that can be achieved. According to the first aspect of the present invention, there is provided a mechanical ignition type sensor which is always urged in a primer collision direction and ignites a primer by colliding with the ignition pin. A trigger lever which is supported and holds the ignition pin against the urging force, and a trigger groove in which the trigger lever can be fitted are formed, and the trigger lever is usually fixed to the trigger lever by a predetermined margin at the periphery of the trigger groove. While engaging to maintain the ignition pin holding state of the trigger lever,
An inertial mass that moves by an inertial force when a predetermined load is applied, and the inertial mass moves beyond the catch allowance when the predetermined load is applied, whereby the trigger lever rotates and the trigger groove is moved. In the mechanical ignition type sensor which is inserted into the ignition pin to release and operate the ignition pin holding state, it is always inserted into the trigger groove of the inertial mass body, and the trigger groove is held in the trigger lever holding state by the inertial mass body. A protrusion that is engaged with an inner peripheral edge of the trigger lever to maintain the predetermined allowance is provided on the trigger lever;
It is characterized by: In the mechanical ignition type sensor according to the first aspect, in a normal state where no load is applied, the ignition pin is located at a position separated from the detonator against the urging force, and the trigger lever is located at the ignition pin. And holds the ignition pin. In addition, the inertial mass enters the rotation locus of the trigger lever, and engages with the trigger lever by a predetermined engagement margin (trigger stroke) at the peripheral edge of the trigger groove to prevent the rotation of the trigger lever and cause the ignition pin to rotate. The holding state is maintained. Further, the protrusion provided on the trigger lever is fitted into the trigger groove of the inertial mass body, and is engaged with the inner peripheral edge of the trigger groove to maintain the predetermined allowance. On the other hand, when a large acceleration acts on the mechanical ignition sensor, the inertial mass moves by inertia. At the time when the inertial mass body moves by inertia beyond the hook margin, the trigger lever faces the trigger groove. For this reason, the trigger lever rotates to fit into the trigger groove, and is separated from the ignition pin to release the holding of the ignition pin. As a result, the ignition pin moves due to the urging force, collides with the primer, and the primer is ignited. Here, in this mechanical ignition type sensor, the projection provided on the trigger lever is engaged with the inner peripheral edge of the trigger groove as described above, whereby the predetermined engagement between the inertial mass and the trigger lever is achieved. Have maintained their teens. That is, the predetermined allowance between the inertial mass body and the trigger lever is determined by the position at which the protrusion of the trigger lever is formed, and does not depend on the dimensions of each component of the sensor. Unaffected). Therefore, by setting only the formation position (dimension) of the protrusion of the trigger lever with high accuracy, the predetermined operation sensitivity of the sensor can be reliably maintained. In other words, even if the dimensional tolerance of each component of the sensor is not strictly set, the predetermined operation sensitivity can be maintained, and the cost can be reduced. Furthermore, in this mechanical ignition type sensor,
Since the protrusion provided on the trigger lever is always fitted into the trigger groove of the inertial mass body, the trigger lever is quickly fitted into the trigger groove during acceleration. As described above, the mechanical ignition type sensor according to the present invention can set the dimensional tolerance of each component large while reliably maintaining the predetermined operation sensitivity, and can reduce the cost. FIG. 1 is a sectional view showing the entire configuration 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 constituting a sensor main body. The case 12 is formed in a cylindrical shape having a bottom wall 14 at one end, and a plate 16 similarly constituting a sensor main body portion is fixed and sealed by a cover 18 on the opening side. Case 1
A through hole 20 is formed on the bottom wall 14 of the second member 14 on the axis thereof.
The case 12 has a cylindrical guide hole 22 formed therein. An ignition pin 24 is arranged inside the case 12. The ignition pin 24 is composed of a substantially cylindrical main body 26 and a projection 28 integrally formed from a bottom wall 26A of the main body 26, and slides in the case 12 along the axis. By moving, the convex portion 28 can enter the through hole 20 formed in the bottom wall 14. The projection 28 projects outside from the through hole 20 in a state where the ignition pin 24 (the main body 26) has moved to the side of the bottom wall 14 of the case 12 most. A firing spring 30 is arranged between the plate 16 fixed to the opening side of the case 12 and the ignition pin 24, and the ignition pin 24 is always inserted through the through hole 20.
In the direction of. An inertial mass body 32 is disposed in the guide hole 22 of the case 12. The inertial mass body 32 is formed in a substantially cylindrical shape, and is accommodated in the guide hole 22 so as to be movable in the axial direction. A bias spring 34 is disposed between the inertial mass body 32 and the plate 16 and always biases the inertial mass body 32 toward the bottom wall 14. A trigger lever 36 is arranged between the inertial mass body 32 and the ignition pin 24. As shown in detail in FIG. 2, the trigger lever 36 has one end in the longitudinal direction having the shaft 3.
8 rotatably supported. The distal end of the trigger lever 36 is bent toward the ignition pin 24 to form an engagement portion 40, which can be engaged with the ignition pin 24. That is, the rotation of the trigger lever 36 about the axis 38 allows the engagement portion 40 to approach or separate from the ignition pin 24. In a state where the engaging portion 40 of the trigger lever 36 is engaged with the main body 26 of the ignition pin 24, the ignition pin 24 urged by the firing spring 30 is moved to a position where the convex portion 28 is pulled out of the through hole 20. keeping. As shown in detail in FIG. 2, a slide holding portion 42 is formed on the side opposite to the ignition pin 24 near the distal end of the trigger lever 36 so as to protrude toward the inertial mass body 32. And the slide holding section 42
A protruding portion 43 is further formed to project from the tip of. The slide holding portion 42 has a length f and corresponds to the trigger groove 44 formed in the inertial mass body 32, and can enter the trigger groove 44 when the inertial mass body 32 moves. It is configured as follows. On the other hand, the protrusion 43
Is formed so as to protrude continuously from the tip of the slide holding portion 42, and is always fitted into the trigger groove 44 of the inertial mass body 32, and when the trigger lever 36 is held by the inertial mass body 32. The slide holding portion 42 is kept in contact with the inertial mass body 32 by engaging with the inner peripheral edge of the trigger groove 44. As a result, the inertial mass body 32 is normally moved most by the bias spring 34 to the bottom wall 1 of the case 12.
4 and in this state, the inertial mass 3
2 comes into contact with the slide holding portion 42 of the trigger lever 36, the inner peripheral edge of the trigger groove 44 is engaged with the projection 43 of the trigger lever 36, and the engagement portion 40 of the trigger lever 36 is The ignition pin 2 is engaged with the main body 26.
4 is held at a position where the convex portion 28 is pulled out from the through hole 20. Further, the inertial mass body 32 is
When moving in the direction away from 4, the inertial mass body 32
Moves relative to the slide holding portion 42 of the trigger lever 36 while linearly contacting the slide holding portion 42, and the slide holding portion 42
4. On the other hand, a safety lever 45 is disposed at the center of the plate 16 (between the ignition pin 24 and the cover 18). The safety lever 45 includes a disc-shaped main body 46,
And a shaft portion 47 integrally fixed to the main body portion 46, and supported by the plate 16 and the cover 18 so as to be movable along the axis. The arm portion 48 is formed on the safety lever 45. The arm 48 is the plate 1
6 and extends toward the inertial mass body 32, and a locking portion 50 is formed at the tip. The locking portion 50 is inserted into an engagement groove 52 formed along the axial direction at the end of the inertial mass body 32. Thus, in a state in which the locking portion 50 approaches one end 52A of the engagement groove 52 (a state shown in FIG. 1), the inertial mass body 32
(The arm portion 48), the movement of the inertial mass body 32 is prevented in the axial direction when the locking portion 50 is separated from the one end 52 </ b> A of the engagement groove 52 (the state shown in FIG. 3). This is a configuration that enables movement. Further, as shown in FIG. 3, when the locking portion 50 of the safety lever 45 is separated from one end 52A of the engaging groove 52 (close to the other end 52B of the engaging groove 52), the safety is further improved. When the lever 45 moves in the axial direction, the locking portion 50 is engaged with the other end 52 </ b> B of the engagement groove 52, and the inertial mass body 32 is forcibly moved together with the safety lever 45. A compression coil spring 54 is disposed between the safety lever 45 and the cover 18, and a locking portion 50 is provided.
Always biases the safety lever 45 in a direction approaching one end 52A of the engagement groove 52. The shaft portion 47 of the safety lever 45 projects outside through a through hole 19 formed in the cover 18, and an operation plate 58 is attached thereto. The operation plate 58 can be operated from the outside by a release device (not shown), and the release device can be fitted between the operation plate 58 and the cover 18. That is, the release device is operated by the operation plate 58 and the cover 1
8, the engaging portion 50 is normally engaged with the engaging groove 52 by the urging force of the compression coil spring 54.
The safety lever 45 approaching the one end 52A is moved in the axial direction by a predetermined amount so that the locking portion 50 is separated from the one end 52A of the engagement groove 52. The mechanical ignition type sensor 10 having the above configuration
Is mounted on a plate 56 of a gas generator (not shown) of an airbag device or a pretensioner device, for example. The gas generator contains a gas generating agent, and a plate 56 is provided with a primer 60 for igniting and burning the gas generating agent. Detonator 60
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 20 of the case 12 faces the primer 60, and the projection 28 of the ignition pin 24 that can protrude from the through hole 20 can collide with the primer 60. Next, the operation of this embodiment will be described. In the mechanical ignition type sensor 10 configured as described above, the ignition pin 24 is normally separated from the primer 60 against the urging force of the firing spring 30 as shown in FIG. 20), the trigger lever 36 holds the ignition pin 24 with the engagement portion 40 engaged with the main body 26 of the ignition pin 24. Further, the inertial mass body 32 is biased to the bottom wall 14 by the bias spring 34.
, That is, into the rotation locus of the trigger lever 36, and the inner peripheral wall abuts the slide holding portion 42 of the trigger lever 36 to prevent the rotation of the trigger lever 36 and maintain the ignition pin holding state. ing. Further, the protrusion 43 provided on the trigger lever 36 is fitted into the trigger groove 44 of the inertial mass body 32 and is engaged with the inner peripheral edge of the trigger groove 44 so that the slide holding portion 42 is moved by the inertial mass body. 32
(A predetermined margin f). Further, in the safety device operating state (sensor inoperable state), the locking portion 50 of the safety lever 45 approaches one end 52A of the engaging groove 52 of the inertial mass body 32 and this state is changed to the compression coil spring 54. Is maintained by the urging force. Therefore, in this state, even if a large acceleration acts on the mechanical ignition type sensor 10, the inertial mass body 32 connects the one end 52 </ b> A of the engagement groove 52 to the safety lever 4.
5 does not move (the slide holding portion 42 of the trigger lever 36 does not enter the trigger groove 44), and therefore, the trigger lever 36 does not rotate. The ignition pin holding state is not released. On the other hand, when releasing the safety device, the release lever is inserted between the operation plate 58 and the cover 18 so that the safety lever 45 is moved in the axial direction against the urging force of the compression coil spring 54. Moved, as shown in FIG.
When the locking portion 50 is separated from the one end 52A of the engagement groove 52, the inertial mass body 32 can be moved in the axial direction, and the safety device is inoperative (sensor operable). Here, when a large acceleration acts on the mechanical ignition type sensor 10, the inertial mass body 32 inertially moves in the direction of the plate 16, and the trigger groove 44 corresponds to the rotation locus of the trigger lever 36. When the slide holding portion 42 of the trigger lever 36 faces the trigger groove 44 of the inertial mass body 32 and is released from holding, the direction in which the ignition pin 24 urged by the firing spring 30 separates from the ignition pin 24. The trigger lever 36 pressed toward is rotated in a direction away from the ignition pin 24. This allows
The engaging portion 40 of the trigger lever 36 is connected to the main body 2 of the ignition pin 24.
6 to release the holding of the ignition pin 24, whereby the ignition pin 24 moves in the axial direction by the urging force of the firing spring 30, and the projection 28 projects outward from the through hole 20 (FIG. 4 state). As a result, the projection 28 of the ignition pin 24 collides with the primer 60, and the primer 60 is ignited. When the primer 60 is ignited, the gas generating agent of the gas generator is ignited and burned, and, for example, an air bag device or a pretensioner device is operated. On the other hand, when the mechanical ignition type sensor 10 is forcibly activated at the time of disposal of a vehicle or the like, when the release device is further operated to fit between the operation plate 58 and the cover 18, the compression coil The safety lever 45 is further moved in the axial direction against the urging force of the spring 54. For this reason, FIG.
As shown in FIG. 7, the engaging portion 50 is engaged with the other end portion 52B of the engaging groove 52, the inertial mass body 32 is forcibly moved in the axial direction, and the slide holding portion 42 of the trigger lever 36 is moved to the inertial mass body 32. The holding thereof is released in opposition to the trigger groove 44 of FIG. Thereafter, as in the case of the above-described large acceleration action, the ignition pin 24 moves by the urging force of the firing spring 30, the projection 28 collides with the primer 60, and the primer 60 is ignited. Is ignited and burned. Here, in this mechanical ignition type sensor 10,
In the normal state (the state shown in FIGS. 1 and 2), the convex portion 43 provided on the trigger lever 36 is engaged with the inner peripheral edge of the trigger groove 44 as described above, so that the slide holding portion 42 has an inertia. The state in which it is in contact with the mass body 32 (in other words, the predetermined allowance f between the inertial mass body 32 and the trigger lever 36) is maintained. That is, the predetermined engagement allowance f between the inertial mass body 32 and the trigger lever 36 (slide holding portion 42) is determined by the formation position of the protrusion 43 of the trigger lever 36, and depends on the dimensions of each component of the sensor. No (not affected by variations in dimensions of each component). Therefore, the protrusion 43 of the trigger lever 36
By setting only the formation position (dimension) of the sensor with high accuracy, the predetermined operation sensitivity of the mechanical ignition type sensor 10 can be reliably maintained. In other words, even if the dimensional tolerance of each component of the mechanical ignition type sensor 10 is not strictly set, the predetermined operation sensitivity can be maintained, and the cost can be reduced. Further, in the mechanical ignition type sensor 10, the convex portion 43 provided on the trigger lever 36 is always fitted into the trigger groove 44 of the inertial mass body 32.
At the time of acceleration, the slide holding portion 42 is quickly fitted into the trigger groove 44. As described above, in the mechanical ignition type sensor 10 according to the present embodiment, the dimensional tolerance of each component can be set large while reliably maintaining the predetermined operation sensitivity, and the cost can be reduced. it can. As described above, the mechanical ignition type sensor according to the present invention can set a large dimensional tolerance of each component while reliably maintaining a predetermined operation sensitivity, and can reduce the cost. This has an excellent effect that it can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view showing an overall configuration of a mechanical ignition type sensor according to an embodiment of the present invention in a safety device operating state. FIG. 2 is a cross-sectional view illustrating a correspondence relationship between a slide holding portion and a protrusion provided on a trigger lever of the mechanical ignition sensor according to the embodiment of the present invention and a trigger groove of an inertial mass body. FIG. 3 is a cross-sectional view showing the entire configuration of the mechanical ignition type sensor according to the embodiment of the present invention, in a state where the safety device is released. FIG. 4 is a cross-sectional view illustrating an entire configuration of a mechanical ignition type sensor according to an embodiment of the present invention in a sensor operating state. FIG. 5 is a cross-sectional view showing a general configuration of a mechanical ignition sensor according to an embodiment of the present invention, in a forced ignition state. [Description of Signs] 10 Mechanical ignition sensor 24 Ignition pin 32 Inertial mass body 36 Trigger lever 42 Slide holding part 43 Convex part 44 Trigger groove

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-108898 (JP, A) JP-A-7-108897 (JP, A) JP-A-7-108893 (JP, A) JP-A-7-10888 108895 (JP, A) JP-A-7-69170 (JP, A) JP-A-7-108896 (JP, A) JP-A-6-2222069 (JP, A) JP-A-2-92757 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B60R 21/16-21/32 B60R 22/00-22/48

Claims (1)

(57) [Claim 1] An ignition pin which is always urged in the direction of a primer collision and ignites a primer by colliding, and is rotatably supported, and is provided with the ignition pin in response to the urging force. A trigger lever for holding against the trigger lever; and a trigger groove into which the trigger lever can be fitted. The trigger pin of the trigger lever is normally engaged with the trigger lever by a predetermined margin at the periphery of the trigger groove. An inertial mass body that moves by an inertial force when a predetermined load is applied, while maintaining the holding state, and the trigger lever is moved by the inertial mass beyond the hook allowance when the predetermined load is applied. In a mechanical ignition type sensor which rotates and is inserted into the trigger groove to release the ignition pin holding state and operates, the sensor is always inserted into the trigger groove of the inertial mass body. In the trigger lever holding state by the inertial mass body, a protrusion that engages with an inner peripheral edge of the trigger groove to maintain the predetermined allowance is provided on the trigger lever. Type sensor.