JPH06235732A - Mechanical firing sensor - Google Patents

Abstract

PURPOSE:To obtain a downsized mechanical firing sensor in which erroneous function is prevented positively by blocking unnecessary movement of an inertial mass positively thereby sustaining operable state positively. CONSTITUTION:A lock lever 72 is disposed retractively in the track of an inertial mass 40. Engaging part 84 of the lock lever 72 corresponds to the engaging groove 41 in the inertial mass 40 and when they engage each other, rotation of the lock lever 72 is blocked thus blocking movement of the inertial mass 40. In other words, urging force of a return spring 86 does not substantially function to block movement of the inertial mass 40. Consequently, even a so- called tension type safety device can employ a small-sized return spring 86 having low urging force thus realizing total downsizing.

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, the webbing attached to an occupant is pulled back by a predetermined amount when the vehicle suddenly decelerates to forcibly remove the slack of the webbing for the occupant to tension the webbing. There is one provided with a so-called pretensioner with improved restraint property.

In this type of pretensioner, there are a pretensioner having a structure for tensioning the webbing by forcibly rotating the winding shaft of the webbing retractor and a structure for tensioning the webbing by forcibly pulling the buckle. However, for example, in a structure in which the webbing is tensioned by pulling the buckle, a gas generator equipped with a mechanical ignition sensor is provided. A cylinder is arranged in the gas generator and is connected to the buckle via a wire or the like.

When the vehicle suddenly decelerates, this is detected by a mechanical ignition type sensor, the gas generator is activated, gas is instantaneously generated and the cylinder is moved, and this moving force is transmitted to the buckle via the wire. The buckle is forcibly moved and the webbing is tensioned.

Here, the mechanical ignition type sensor used in such a pretensioner or the like must be equipped with a safety device because it must not malfunction before it is properly installed in the gas generator. That is, a lock member that can enter the movement trajectory of the inertial body is arranged, and when this lock member enters the movement trajectory of the inertial body, an unnecessary impact load acts (for example, a sudden fall. If the inertial body tries to move unnecessarily (in such a case), the locking member engages with the inertial body and prevents the movement.

After the gas generator is properly installed, the release knob is operated to disengage the lock member from the trajectory of the inertial body so that the inertial body can be moved. The ignition sensor is set.

[0007]

By the way, the above-mentioned lock member and the release knob for moving the lock member have a releasing operation moving direction which is the same as the moving direction of the inertial body, that is, a conventional machine equipped with a so-called tension type safety device. In the ignition type sensor, in order to reliably prevent unnecessary movement of the inertial body, the biasing force of the return spring that biases the lock member in the direction of the movement of the inertial body is sufficiently large (for example, It was necessary to be able to withstand even acceleration of several tens of times of the detected acceleration). For this reason, the return spring becomes large and heavy, and the sensor inevitably becomes large and heavy as a whole, and this is also a cause of high cost, and there is room for improvement in this respect.

In consideration of the above facts, the present invention surely blocks the unnecessary movement of the inertial mass body, reliably maintains the inoperable state, reliably prevents the malfunction, and realizes it with a small shape. The aim is to obtain a mechanical ignition sensor.

[0009]

A mechanical ignition sensor according to the present invention is always biased by a bias spring,
Inertia mass that moves against the biasing force of the bias spring due to inertial force when a predetermined load is applied, and the movable mass that is arranged correspondingly to the detonator, and is moved by the biasing force of the firing spring to ignite the detonator. In a mechanical ignition type sensor having a pin, the inertial mass body is positioned corresponding to the inertial mass body, and is rotatably supported and rotated by a support shaft so that the inertial mass body can move in and out of the inertial mass body. In a state of entering the inertial mass body in the movement path, it has an engaging portion that engages with the inertial mass body, and in the state where the engaging portion engages with the inertial mass body,
A lock lever that locks with the inertial mass body and is prevented from rotating in a direction in which the inertial mass body moves away from the trajectory of the inertial mass body, and that blocks the movement of the inertial mass body, and in the moving direction of the inertial mass body. It is arranged so that it can move along,
A release operation member that is connected to the lock lever and rotates to rotate the lock lever around a support shaft to disengage the engagement portion from the movement track of the inertial mass body;
And a return spring that constantly biases the release operation member in a direction in which the engagement portion of the lock lever enters the movement trajectory of the inertial mass body.

[0010]

In the mechanical ignition type sensor having the above structure, in the operable state with the safety device released, the ignition pin is located away from the detonator against the biasing force of the firing spring, and the inertial mass body is bias spring. Is held in place by. Further, the lock lever is separated from the movement trajectory of the inertial mass body, and further, the release operation member holds the lock lever in this state against the biasing force of the return spring.

In this state, when a large acceleration acts on the mechanical ignition sensor, the inertial mass body moves inertially, and the ignition pin moves by the urging force of the firing spring to collide with the detonator and ignite the detonator.

Here, in the mechanical ignition type sensor, the safety device can be activated to make it inoperable.

That is, in this inoperable state,
The lock lever is released from the holding state by the release operating member and enters the movement trajectory of the inertial mass body, and the release operating member keeps the lock lever in this state by the urging force of the return spring.

In this state, when an unnecessary impact load is applied to the mechanical ignition type sensor, the inertial mass body engages with the engaging portion of the lock lever, and the lock lever and the inertial mass body are locked with each other. Become. As a result, the lock lever itself is blocked by the inertial mass from rotating in the direction in which the inertial mass moves away from the trajectory of the inertial mass, and remains in the trajectory of the inertial mass. The body is also prevented from moving itself. In this way, when the sensor is inoperable (the lock lever has entered the movement trajectory of the inertial mass body and the lock lever and the inertial mass body have locked each other), the force of the return spring does not , The inertial mass interacts with the lock lever and is blocked from moving. That is,
In other words, the urging force of the return spring that urges the lock lever in the direction of entering the movement path of the inertial mass body through the release operation member does not substantially act as the movement blocking force of the inertial mass body.

Therefore, even if the releasing operation moving direction of the lock lever or the releasing operation member for moving the locking lever is the same as the moving direction of the inertial mass body (even if the structure of the safety device is a so-called tension type structure), There is no need to increase the biasing force of the return spring. This makes it possible to prevent the inertial mass from moving even if the return spring is small and light, and the mechanical ignition sensor can be made compact and lightweight as a whole, and the cost can be reduced. You can also plan.

Further, since the urging force of the return spring can be reduced in this way, the release operation member is operated against the urging force of the return spring to disengage the lock lever from the locus of movement of the inertial mass body, and the mechanical ignition sensor. Even when is set to the operable state (the state in which the safety device is released), it can be operated with a small operation force, and the operability is also improved.

As described above, in the mechanical ignition type sensor, unnecessary movement of the inertial body is surely prevented, the inoperable state is surely maintained, and the malfunction can be surely prevented, and further, it is realized in a small shape. You can do it.

[0018]

1 is an exploded perspective view of a mechanical ignition type sensor 10 according to an embodiment of the present invention. Further, FIG. 2 shows a cross-sectional view of the mechanical ignition sensor 10.
3 and 4 are longitudinal sectional views of the mechanical ignition type sensor 10. Further, FIG. 5 shows a cross-sectional view of the mechanical ignition sensor 10 taken along the line 5-5 of FIGS. 3 and 4.
FIG. 6 shows a cross-sectional view of the mechanical ignition type sensor 10 taken along line 6-6 of FIGS. 3 and 4, and FIG. 7 shows 7-7 of FIG.
A cross-sectional view of the mechanical ignition sensor 10 along a line is shown.

The mechanical ignition type sensor 10 has a sensor cover 12. The sensor cover 12 has a bottom wall 1 at one end.
4 is formed in a substantially cylindrical shape, and a through hole 16 is formed in the bottom wall 14 on the axis. This sensor cover 1
In the inside of 2, the body block 18 and the lid block 2
0 is placed. The body block 18 is formed in a substantially cylindrical block shape, and the bottom wall 22 is connected and fixed to the bottom wall 14 of the sensor cover 12. The lid block 20 is formed in a disk shape, and is connected and fixed to the opening side end of the body block 18. That is,
The body block 18 and the lid block 20 are integrally fastened from the outside by the sensor cover 12, and thus,
A main body portion of the mechanical ignition type sensor 10 is configured. Further, an O-ring 24 is arranged between the sensor cover 12 and the lid block 20 to ensure hermetic sealing. The body block 18 may be divided into a plurality of parts for the convenience of manufacture or assembly.

A through hole 26 and a through hole 28 are formed in the bottom wall 22 of the body block 18 and correspond to an ignition pin 30 and a rod 42, which will be described later.

An ignition pin 30 is arranged inside the body block 18. As shown in FIG. 6, the ignition pin 3
0 is formed in a generally L-shaped cross section by bending a plate material and is slidably arranged in a guide groove 32 formed in the body block 18. In this case, the ignition pin 30 (that is, the guide groove 32)
Is located on one side in the radial direction of the body block 18 (the main body portion of the mechanical ignition sensor 10) and is movable along the axial direction of the body block 18.

The ignition pin 30 has a pointed portion 34 projectingly formed on one end portion of the L-shape (end portion on the axial center of the body block 18) and on the side corresponding to the bottom wall 22 of the body block 18. . The pointed portion 34 projects to the outside from the above-described through hole 26 formed in the bottom wall 22 when the ignition pin 30 is moved to the side of the bottom wall 22 of the body block 18 most.

On the other hand, a holder 36 is integrally connected and fixed to the lower portion (lower side in FIG. 3) of the ignition pin 30. A firing spring 38 is arranged between the holder 36 and the lid block 20, and always urges the ignition pin 30 toward the bottom wall 22 (through hole 26).

On the other hand, as shown in FIG. 6, on the side of the ignition pin 30, that is, on the other side in the radial direction of the body block 18 (the main body portion of the mechanical ignition type sensor 10), the inertial mass body 4 is provided.
0 is placed. The inertial mass body 40 is formed in an arcuate shape in a front view and a rectangular shape in a side view, that is, a so-called gutter shape, and is fixed in a state of penetrating the through hole 28 of the bottom wall 22.
It is movably held by the body block 18 along the axial direction thereof. Further, a bias spring 44 is arranged between the inertial mass body 40 and the lid block 20, and always urges the inertial mass body 40 toward the bottom wall 22. The inertial mass body 40 can move against the biasing force of the bias spring 44 by the inertial force when a predetermined load is applied.

An arm portion 46 extends toward the opposite side of the rod 42 from the upper side portion (upper side in FIGS. 3, 4 and 6) of the inertial mass body 40, and a trigger lever 50 to be described later.
And the auxiliary roller 66. Furthermore, on the side wall of the inertial mass body 40 on the bias spring 44 side,
A single engagement groove 41 is formed and corresponds to a lock lever 72 described later.

A trigger lever 50 is arranged laterally of the inertial mass body 40 and directly above the ignition pin 30. The trigger lever 50 is formed in a U-shaped cross section by bending a plate material, and a spindle 52 is attached to one end in the longitudinal direction. The support shaft 52 is held in a shaft support hole 54 formed in the body block 18, and thereby the trigger lever 50 is rotatably supported in a direction in which the trigger lever 50 comes in contact with and separates from the ignition pin 30. An engagement portion 56 is formed so as to project on the back surface side of the trigger lever 50 (the side of the ignition pin 30). The engaging portion 56 engages with the end portion of the ignition pin 30 on the side of the pointed portion 34, so that the pointed portion 34 of the ignition pin 30 urged by the firing spring 38 is separated from the through hole 26. keeping.

The other side of the trigger lever 50 (the support shaft 52
A roller 58 is arranged at the tip end on the opposite side).
The roller 58 is located apart from the engaging portion 56 with respect to the rotation center of the trigger lever 50, that is, the support shaft 52, and the support shaft 60 is attached to the roller 58. The support shaft 60 is slidably inserted into a long hole 62 formed in the trigger lever 50, whereby the roller 58 is slidable along the long hole 62.

This roller 58 corresponds to the inertial mass body 40 described above.
It corresponds to the lower surface side of the arm portion 46 of the
When the engaging portion 56 separates from the ignition pin 30 by rotating to release the holding thereof, the roller 58 moves while rolling the lower surface side of the arm portion 46 to the side surface side.

Further, normally, the inertial mass body 40 is located at the position closest to the bottom wall 22 of the body block 18 by the bias spring 44. In this state, the lower surface side of the arm portion 46 of the inertial mass body 40 is the trigger lever 50. The roller 58 of the trigger lever 50 and the engaging portion 56 of the trigger lever 50.
Is engaged with the end portion of the ignition pin 30 and holds the ignition pin 30 at a position where its apex 34 is separated from the through hole 26.

On the other hand, an auxiliary roller 66 is arranged immediately above the arm portion 46 of the inertial mass body 40 so as to oppose the roller 58. A support shaft 68 is attached to the auxiliary roller 66, and the support shaft 68 is held in a shaft support hole 70 formed in the body block 18, whereby the auxiliary roller 66 is provided.
Is rotatable. The auxiliary roller 66 corresponds to the upper surface side of the arm portion 46 of the inertial mass body 40,
The arm portion 46 of the inertial mass body 40 is nipped and held in a rolling contact state with the roller 58. Therefore, when the trigger lever 50 rotates and the engaging portion 56 separates from the ignition pin 30 and releases its holding, the arm portion 46 moves on the upper and lower surfaces of the roller 58 and the auxiliary roller 66.

The side of the trigger lever 50 (the lid block 20
A lock lever 72 is arranged on the side of (). The lock lever 72 is formed in a block shape, and is rotatably supported by a shaft 73. The shaft 73 is positioned orthogonal to the support shaft 52 that supports the trigger lever 50 described above. Therefore, the lock lever 72 rotates in a direction orthogonal to the rotation direction of the trigger lever 50, and the inertial mass body is rotated. It is configured to enter and leave the movement trajectory of 40.

An engaging portion 84 is formed on the side wall of the lock lever 72 on the side of the inertial mass body 40 so as to project therefrom. The engagement portion 84 corresponds to the engagement groove 41 formed in the inertial mass body 40, and when the lock lever 72 rotates around the shaft 73 and enters the movement track of the inertial mass body 40. ,
It can be fitted into the engaging groove 41. In the state where the engaging portion 84 is fitted in the engaging groove 41, the lock lever 72 and the inertial mass body 40 are in a state of being locked with each other, whereby the lock lever 72 itself is in the inertial mass body 40.
Thus, the inertial mass body 4 is prevented from rotating in the direction (direction of arrow A in FIG. 2) away from the locus of movement of the inertial mass body 40.
The inertial mass body 40 remains in the movement locus of 0 and the inertial mass body 40 is prevented from moving by the lock lever 72 regardless of the action of a predetermined load.

A U-shaped guide groove 82 is formed at the end of the lock lever 72 opposite to the shaft 73. The guide groove 82 corresponds to the spring pin 80 of the shaft 74 described later.

On the other hand, on the side of the lock lever 72, a shaft 74 which constitutes a release operation member is arranged. The shaft 74 has a support hole 76 formed in the lid block 20.
And is supported via a cap 77 and an O-ring 78. As shown in FIG. 5, a spring pin 80 is fixed to one end of the shaft 74. The spring pin 80 can be fitted into the guide groove 82 formed in the lock lever 72. That is, when the shaft 74 moves in the axial direction, the spring pin 80 is fitted into the guide groove 82 and the moving force of the shaft 74 is transmitted to the lock lever 72, and the lock lever 72 is rotated along with the movement of the shaft 74. Can be made.

As shown in FIG. 7, the tip of the shaft 74 protruding from the support hole 76 of the lid block 20 to the outside is
The operation knob 88 is attached via the split pin 87, and the shaft 74 can be moved from the outside in the axial direction.

A return spring 86 is arranged between the operation knob 88 and the lid block 20 so as to connect them. The return spring 86 is of a tension type, and one end thereof is locked to the split pin 87 and the other end thereof is locked to the lid block 20. As a result, the operation knob 88, that is, the shaft 74, moves inward in the lid block 20, that is, the engaging portion 8 of the lock lever 72.
4 is always urged in a direction in which the inertial mass body 40 enters the movement trajectory. Therefore, in this state, as shown in FIG. 2, the spring pin 80 of the shaft 74 is at the position most pulled out from the guide groove 82 of the lock lever 72,
Furthermore, the engaging portion 84 of the lock lever 72 is
It enters into the movement locus of 0 and faces the engaging groove 41.

The mechanical ignition type sensor 10 having the above structure.
Is assembled in, for example, a gas generator for a pretensioner (detailed structure is not shown).

The gas generator contains a gas generating agent, and a detonator 90 for igniting and burning the gas generating agent is arranged. The detonator 90 is the detonator piece 9
2 is provided in the second block 2 and faces the through hole 26 formed in the bottom wall 22 of the body block 18 in the state where the mechanical ignition sensor 10 is assembled. The mechanical ignition sensor 10 is fixed by the support ring 94 in this state. Therefore, when the mechanical ignition sensor 10 is assembled to the gas generator, the pointed portion 34 of the ignition pin 30 that can project from the through hole 26 formed in the bottom wall 22 of the body block 18 can collide with the detonator 90. Has become. An O-ring 96 is arranged between the sensor cover 12 and the mounting portion of the gas generator to ensure hermetic sealing.

Next, the operation of this embodiment will be described. In the mechanical ignition sensor 10 of this embodiment configured as described above,
Normally, as shown in FIGS. 2 to 4, the ignition pin 30 resists the biasing force of the firing spring 38 and detonates 90.
The trigger lever 50 is located at a position separated from (the through hole 26 of the body block 18), and the engagement portion 56 of the trigger lever 50 is the ignition pin 30.
Holds the ignition pin 30 by engaging with the end of the ignition pin 30. Further, the inertial mass body 40 is located at a position closest to the bottom wall 22 by the bias spring 44, that is, the arm portion 46 enters the rotation locus of the trigger lever 50.
Is held and held in a rolling contact state between the roller 58 of the trigger lever 50 and the auxiliary roller 66. Therefore, the arm 46 prevents the trigger lever 50 from rotating and maintains the ignition pin holding state.

Further, the lock lever 72 is released from the holding of the shaft 74 by the spring pin 80 (at the position where the spring pin 80 is most pulled out from the guide groove 82), and the engaging portion 84 moves the inertial mass body 40. It enters the locus and faces the engaging groove 41 of the inertial mass body 40.
Further, the shaft 74 maintains the lock lever 72 in this state by the urging force of the return spring 86.

Here, by using the release arm X, the operation knob 88 is operated to bring the mechanical ignition type sensor 10 into an operable state.

That is, as shown in FIGS. 8 and 9, the release arm X is inserted between the operation knob 88 and the lid block 20, and the shaft 74 is removed from the lid block 20 against the urging force of the return spring 86. Move in the direction to get out. As a result, the shaft 74 moves in the axial direction together with the spring pin 80, and the spring pin 80 moves in the guide groove 8
2 into the lock lever 72 by moving the shaft 74 into the moving force.
And the lock lever 72 is rotated along with the movement of the shaft 74. As a result, the spring pin 80 of the shaft 74 enters the guide groove 82 of the lock lever 72 as far as possible, and the lock lever 72 moves toward the shaft 7
The engagement portion 84 is rotated around 3 and is in a state of being disengaged from the movement trajectory of the inertial mass body 40. As a result, the mechanical ignition sensor 10 is set in an operable state.

When a large acceleration acts on the mechanical ignition type sensor 10 in such a state, the inertial mass body 40 inertially moves in the direction of arrow B in FIGS. In this case, the inertial mass body 40 moves while the upper surface of the arm portion 46 is in rolling contact with the auxiliary roller 66 and the lower surface of the arm portion 46 is in rolling contact with the roller 58 of the trigger lever 50. When the roller 58 reaches the lower end of the arm 46, the arm 46
Is separated from the rotation locus of the trigger lever 50, and the trigger lever 50 can be rotated around the support shaft 52. Therefore, the trigger lever 50 pressed by the firing pin 30 urged by the firing spring 38 in the direction away from the ignition pin 30 is rotated in the direction away from the ignition pin 30.

As a result, the engaging portion 5 of the trigger lever 50 is
6 is separated from the ignition pin 30 to release the holding of the ignition pin 30, and thus the ignition pin 30 is moved toward the bottom wall 22 by the urging force of the firing spring 38, and the point 34 is removed from the through hole 26. It projects and collides with the detonator 90 of the gas generator, and the detonator 90 is ignited (the state shown in FIGS. 8 and 9). As a result, the gas generating agent of the gas generator is ignited and combusted, and, for example, the pretensioner is operated.

Here, in this mechanical ignition type sensor 10,
An inertial mass body 40 is arranged on one side in the radial direction of a main body portion formed in a cylindrical shape by the body block 18, the lid block 20, and the sensor cover 12, and the ignition mass 30 and the trigger lever 50 move up and down on the other side in the radial direction. Since the parts are arranged, the parts do not erode each other's arrangement space, and thus no wasted space is produced as a whole.

Therefore, unlike the conventional mechanical ignition type sensor, the overall shape does not become large in order to secure the space for disposing one component, and the size can be extremely reduced.

When the inertial mass body 40 inertially moves and the trigger lever 50 rotates about the support shaft 52, the roller 58 of the trigger lever 50 rolls and comes into contact with the arm portion 46 of the inertial mass body 40. To rotate, trigger lever 50
The frictional force between the (roller 58) and the inertial mass body 40 is reduced, and the operation sensitivity of the mechanical ignition sensor 10 is stabilized. Thus, without increasing the mass of the inertial mass body 40, the adverse effect of the frictional force between the trigger lever 50 and the inertial mass body 40 can be reduced and stable operability can be ensured.

Further, in the mechanical ignition sensor 10, the roller 58 is slidably supported in the elongated hole 62 formed in the trigger lever 50, so that the arm portion 46 of the inertial mass body 40 is in the initial position (that is, As shown in FIG. 3, the lower surface of the roller 58 is in contact with the roller 58.
After reaching the switching position (that is, the edge of the lower surface wall), the roller 58 slides along the long hole 62 and rolls to the side surface of the arm portion 46 only by moving extremely minutely.
Therefore, the inertial mass body 40 inertially moves, the trigger lever 50 rotates, and the engaging portion 56 releases the holding of the ignition pin 30 with certainty, and more reliably and stably operates.

Furthermore, in the mechanical ignition type sensor 10,
The arm portion 46 of the inertial mass body 40 is nipped and held in a rolling contact state by the roller 58 of the trigger lever 50 and the auxiliary roller 66 arranged so as to face the roller 58, so that the trigger lever 50 is pushed. Pressure (Ignition pin 30
Even if a force (pressing the trigger lever 50) acts on the inertial mass body 40, it is received by the auxiliary roller 66, and as a result, the inertial mass body 40 does not generate a moment around the rod 42.

Therefore, when the inertial mass body 40 inertially moves, the inertial mass body 40 and the rod 42 holding the inertial mass body 40 are held.
The frictional force between and becomes smaller, and the inertial mass body 40 needs to move only against the rolling resistance with the auxiliary roller 66. Therefore, when a large acceleration acts on the mechanical ignition type sensor 10, the inertial mass body 40 moves smoothly and operates more reliably and stably.

Here, in the mechanical ignition type sensor 10,
A safety device can be activated to disable it.

That is, by setting the release arm X so that it is pulled out from between the operation knob 88 and the lid block 20, the shaft 74 moves in the direction to enter the lid block 20 by the urging force of the return spring 86. The spring pin 80 moves in the axial direction together with the shaft 74. As a result, the spring pin 80 gradually moves out of the guide groove 82, transmits the moving force of the shaft 74 to the lock lever 72, and the lock lever 72 is rotated as the shaft 74 moves. As a result, the spring pin 80 of the shaft 74 comes out of the guide groove 82 of the lock lever 72 most, and the lock lever 72 is rotated around the shaft 73 so that the engaging portion 84 moves along the locus of the inertial mass body 40. It enters into the inside and faces the engagement groove 41. As a result, the mechanical ignition sensor 10 is set in the inoperable state (that is, the above-described state shown in FIGS. 2 to 4).

That is, in this inoperable state,
The lock lever 72 is a spring pin 80 of the shaft 74.
Has been released and has entered the movement path of the inertial mass body 40, and the shaft 74 maintains the lock lever 72 in this state by the urging force of the return spring 86.

In this state, the mechanical ignition type sensor 10
When an unnecessary impact load is applied to the lock lever 72, the engagement groove 41 of the inertial mass body 40 is engaged with the engagement portion 84 of the lock lever 72, and the lock lever 72 and the inertial mass body 40 are locked to each other (see FIG. 2 is indicated by a chain double-dashed line). As a result, the lock lever 72 itself has the inertial mass body 40.
Thus, the inertial mass body 4 is prevented from rotating in the direction (direction of arrow A in FIG. 2) away from the locus of movement of the inertial mass body 40.
0 remains in the movement locus, and the lock lever 72
The inertial mass body 40 is also prevented from moving by itself.

As described above, the mechanical ignition sensor 10 is in the inoperable state (the lock lever 72 enters the movement locus of the inertial mass body 40, and the engaging portion 84 of the lock lever 72 and the engagement groove of the inertial mass body 40 are engaged. In the state where 41 are locked to each other), the inertial mass body 40 interacts with the lock lever 72 and is prevented from moving regardless of the biasing force of the return spring 86. That is, in other words, the urging force of the return spring 86 that urges the lock lever 72 in the direction of entering the movement trajectory of the inertial mass body 40 via the shaft 74 (spring pin 80) is the movement of the inertial mass body 40. It does not substantially act as a blocking force.

Therefore, even if the releasing operation moving direction of the lock lever 72 or the shaft 74 for moving the same is the same as the moving direction of the inertial mass body 40 (even if the structure of the safety device is a so-called tension type structure). , Return spring 86
There is no need to increase the urging force of. As a result, even if the return spring 86 is small and light, the movement of the inertial mass body 40 can be prevented, and the mechanical ignition sensor 10 can be made small and light as a whole. It is also possible to reduce the cost.

Further, in this way, the return spring 8
Since the biasing force of 6 can be reduced, the return spring 8
6 operates the operation knob 88 and the shaft 74 against the biasing force of the lock lever 6 to disengage the lock lever 72 from the movement path of the inertial mass body 40, and the mechanical ignition sensor 10 is operable (the safety device is released). Even when doing, it can be operated with a small operation force, and operability is also improved.

Thus, in the mechanical ignition type sensor 10,
It is possible to reliably prevent unnecessary movement of the inertial mass body 40, reliably maintain the inoperable state, and reliably prevent malfunction.
This can be realized with a small shape.

Next, another embodiment of the present invention will be described. The same components as those in the above-described embodiment are designated by the same reference numerals as those in the above-described embodiment and the description thereof is omitted.

FIG. 10 shows a cross-sectional view of a mechanical ignition type sensor 100 according to another embodiment.

In this mechanical ignition type sensor 100, the trigger lever 50 in the mechanical ignition type sensor 10 is omitted. That is, the ignition pin 102 is arranged so as to be movable in a direction orthogonal to the moving direction of the inertial mass body 40, and the collar portion 104 thereof is directly locked by the inertial mass body 40 and held. There is. The engagement margin L ₁ between the inertial mass body 40 and the brim portion 104 of the ignition pin 102 is a value until the engagement groove 41 of the inertial mass body 40 engages with the engagement portion 84 of the lock lever 72. It is set larger than the combined stroke L ₂ .

Also in this mechanical ignition type sensor 100,
In the sensor operable state, the ignition pin 102 is located at a position separated from the detonator 90 against the biasing force of the firing spring 38, and the inertial mass 40 is located at a position closest to the bottom wall 22 by the bias spring 44. At the same time, it engages with the collar portion 104 of the ignition pin 102 and holds the ignition pin 102.

Further, the lock lever 72 is held by the spring pin 80 of the shaft 74, and the engagement portion 84 is in a state of being disengaged from the movement trajectory of the inertial mass body 40.

In such a state, the mechanical ignition type sensor 100
When a large acceleration acts on the inertial mass body 40,
Inertia moves in the direction of arrow B. When the inertial mass body 40 moves and the engagement between the inertial mass body 40 and the flange portion 104 of the ignition pin 102 is released, the ignition pin 102 can be moved, and the ignition pin 102 biases the firing spring 38. The cusp 106 collides with the detonator 90 of the gas generator to ignite the detonator 90. As a result, the gas generating agent of the gas generator is ignited and combusted, and, for example, the pretensioner is operated.

Here, also in the mechanical ignition type sensor 100, the safety device can be operated to make it inoperable.

That is, similarly to the above-described embodiment, the return spring 86 is set by setting the release arm X to be in a state of being removed from between the operation knob 88 and the lid block 20.
Due to the urging force of the shaft 74, the shaft 74 moves in the direction to enter the lid block 20, and the spring pin 80 moves in the axial direction together with the shaft 74. As a result, the spring pin 80 gradually moves out of the guide groove 82, transmits the moving force of the shaft 74 to the lock lever 72, and the lock lever 72 is rotated as the shaft 74 moves. As a result, the spring pin 80 of the shaft 74 comes out of the guide groove 82 of the lock lever 72 most, and the lock lever 72 is rotated around the shaft 73 so that the engaging portion 84 moves along the locus of the inertial mass body 40. It enters into the inside and faces the engagement groove 41. As a result, the mechanical ignition sensor 100 is set in the inoperable state (state shown in FIG. 10).

That is, in this inoperable state,
The lock lever 72 is a spring pin 80 of the shaft 74.
Has been released and has entered the movement path of the inertial mass body 40, and the shaft 74 maintains the lock lever 72 in this state by the urging force of the return spring 86.

In this state, the mechanical ignition type sensor 10
When an unnecessary impact load acts on 0, the engagement groove 41 of the inertial mass body 40 engages with the engagement portion 84 of the lock lever 72, and the lock lever 72 and the inertial mass body 40 are locked to each other ( This is the state shown by the chain double-dashed line in FIG. 10. As a result, the lock lever 72 itself has the inertial mass body 4
The rotation of the inertial mass body 40 is prevented from rotating in the direction (the direction of arrow A in FIG. 10) that deviates from the movement path of the inertial mass body 40, and remains in the movement path of the inertial mass body 40. It is prevented from moving itself. Further, at this time, as described above, the engagement margin L between the inertial mass body 40 and the collar portion 104 of the ignition pin 102 is L.
₁ indicates that the engaging groove 41 of the inertial mass body 40 is the lock lever 72.
Engaging stroke L ₂ until engaging with the engaging portion 84 of
Since the ignition pin 102 is set larger than the above, the ignition pin 102 is still held by the inertial mass body 40, and unnecessary movement is prevented.

As described above, even in the mechanical ignition type sensor 100 of this embodiment, when the sensor is inoperable,
The inertial mass body 40 interacts with the lock lever 72 to prevent movement thereof regardless of the urging force of the return spring 86, and the urging force of the return spring 86 is substantially a movement prevention force of the inertial mass body 40. Does not work.

Therefore, even if the releasing operation moving direction of the lock lever 72 or the shaft 74 for moving the same is the same as the moving direction of the inertial mass body 40 (even if the structure of the safety device is a so-called tension type structure). , Return spring 86
There is no need to increase the urging force of. This makes it possible to prevent movement of the inertial mass body 40 even if the return spring 86 has a small shape and is light, and the mechanical ignition sensor 100 can be made small and light as a whole. It is also possible to reduce the cost.

In each of the above-described embodiments, the mechanical ignition type sensors 10, 100 are used to operate the pretensioner, but the present invention is not limited to this, and other devices that operate when a sudden acceleration is applied. Of course, it can be used for an airbag device, for example.

[0072]

As described above, the mechanical ignition type sensor according to the present invention can surely prevent the unwanted movement of the inertial mass body, maintain the inoperable state, and prevent the malfunction. It has an excellent effect that it can be realized in a small shape.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a mechanical ignition type sensor according to an embodiment of the present invention.

FIG. 2 is a transverse cross-sectional view showing the correspondence relationship between the lock lever and the inertial mass body of the mechanical ignition type sensor according to the embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view showing an arrangement relationship between a lock lever and a trigger lever of the mechanical ignition sensor according to the embodiment of the present invention.

FIG. 4 is a vertical cross-sectional view showing the positional relationship between the lock lever and the inertial mass body of the mechanical ignition sensor according to the embodiment of the present invention.

FIG. 5 is a cross-sectional view taken along line 5-5 of FIGS. 3 and 4 showing the positional relationship between the lock lever and the inertial mass body of the mechanical ignition sensor according to the embodiment of the present invention.

FIG. 6 is a cross-sectional view taken along line 6-6 of FIGS. 3 and 4 showing the positional relationship between the ignition pin, the inertial mass body and the trigger lever of the mechanical ignition type sensor according to the embodiment of the invention.

FIG. 7 is a view showing the connecting relationship between the shaft and the return spring of the mechanical ignition type sensor according to the embodiment of the present invention;
It is sectional drawing which followed the -7 line.

FIG. 8 is a cross-sectional view corresponding to FIG. 2, showing a state after the mechanical ignition sensor according to the embodiment of the present invention is activated.

FIG. 9 is a cross-sectional view corresponding to FIG. 3, showing a state after the mechanical ignition type sensor according to the embodiment of the present invention is activated.

FIG. 10 is a transverse cross-sectional view showing a correspondence relationship between a lock lever, an inertial mass body and an ignition pin of a mechanical ignition type sensor according to another embodiment of the present invention.

[Explanation of symbols]

 10 Mechanical Ignition Type Sensor 30 Ignition Pin 34 Tip 38 Spring Ring 40 Inertia Mass 41 Engagement Groove 44 Bias Spring 50 Trigger Lever 72 Lock Lever 74 Shaft (Release Operation Member) 82 Guide Groove 80 Spring Pin (Release Operation Member) 84 engagement part 86 return spring 88 operation knob (release operation member)

Claims (1)

[Claims] 1. An inertial mass body that is constantly biased by a bias spring and moves by an inertial force against the biasing force of the bias spring when a predetermined load is applied; In a mechanical ignition sensor including an ignition pin that moves by a biasing force of a spring to ignite a detonator, and the inertial mass is positioned corresponding to the inertial mass body and is rotatably supported by a support shaft to rotate. It has an engaging portion that is capable of entering and leaving the movement track of the body and that engages with the inertial mass body in a state of entering the movement track of the inertial mass body, and the engagement portion is provided on the inertial mass body. In the engaged state, they are mutually locked with the inertial mass body, are prevented from rotating in the direction of separating from the movement track of the inertial mass body, and move the inertial mass body. A lock lever for blocking, and a lock lever arranged to be movable along the moving direction of the inertial mass body, coupled to the lock lever, and by moving the lock lever, the lock lever is rotated around a support shaft to engage the engaging portion. A release operation member that disengages from the movement track of the inertial mass body, and a return spring that constantly urges the release operation member in a direction in which the engagement portion of the lock lever enters the movement path of the inertial mass body, A mechanical ignition sensor characterized by being provided with.