JPH06144151A - Shock sensing device - Google Patents

Abstract

PURPOSE:To prevent the fixing of a weight caused by the friction force generated on the contact portion at the initial position by providing a stopper section applying the exciting force of a spring in the vertical direction to hold the weight at the initial position on the outer face of the weight in the shock sensing device of an anti-shock safety system. CONSTITUTION:The rotating action of a firing lever 4 is restricted by a weight 3 against the exciting force of a spring 5 by the coupling between a cam section 3a and a coupling section 4a in the initial state in this rocking starting device. The rocking action of the weight 3 is blocked by the exciting force of the spring 5 via the coupling between the cam section 3a and the coupling section 4a, and a contact face 2a and a stopper section 3b are kept in contact at the initial position. When a large shock G is applied in this state, the weight 3 is rocked around a pin 6 against the spring 5, the cam section 3a is rotated, the coupling of the firing lever 4 is released, the lever 4 is rotated by the spring 5, and a pin 4b collides with a detonator 8.

Description

Detailed Description of the Invention

[0001]

[Object of the Invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact sensing device and is used as a starting sensor for an impact safety system such as an air bag.

[0003]

2. Description of the Related Art Conventionally, as this type of shock sensing device,
As disclosed in Japanese Utility Model Laid-Open No. 3-121945, a housing, a circular weight swingably supported by the housing, an output member rotatably supported by the housing and engaged with the weight, the housing and the output. A spring having a spring disposed between the outer member and the member for rotating the output member by an urging force and for holding the weight at the initial position where the outer surface and the housing abut against the swinging motion. Are known. In this conventional device, when an impact of a predetermined value or more is input, the weight swings against the biasing force of the spring, and the swinging movement of the weight releases the engagement between the output member and the weight. As a result, the output member is rotated by the biasing force of the spring, and as a result, the impact safety system is activated.

Further, as shown in Japanese Patent Application No. 2400177 of the prior application of the present invention, a frame, a weight rotatably supported by the frame, and an output member rotatably supported by the frame and engaged with the weight. And the output member is disposed between the frame and the output member to rotate the output member by an urging force, and the weight is opposed to the stopper pin standing on the side surface of the weight against the rotational sliding action of the weight. It is also known to have a spring that holds the initial position in contact. In this conventional device, when an impact of a predetermined value or more is input, the weight rotates and slides against the biasing force of the spring, and the rotation and sliding operation of the weight releases the engagement between the output member and the weight. ,
As a result, the output member is rotated by the urging force of the spring, and as a result, the impact safety system is activated.

[0005]

However, the above-mentioned first problem
In the conventional apparatus, the swinging motion of the weight is resisted by the biasing force of the spring, and the weight is held in the initial position by the contact between the outer surface of the circular weight and the housing. The outer surface of the spring comes into contact with the swing center of the weight, and the biasing force of the spring acts substantially parallel to the housing at the contact portion. For this reason, the frictional force between the weight and the contact portion is increased due to the slight biting deformation of the housing due to the contact of the weight with the housing, and the weight is fixed to the housing. Even if the above-mentioned impact is input, the weight may not swing, which may lead to malfunction.

Further, in the above-mentioned second conventional device, the rotational sliding movement of the weight is resisted by the urging force of the spring, and the weight is set by the abutment of the stopper pin erected on the side surface of the weight with the frame. Since it is held at the initial position, the position accuracy with respect to the weight of the separate stopper pin and the deformation of the stopper pin due to the torsional stress generated by the offset against the stopper pin weight at the contact area between the stopper pin and the frame, etc. Therefore, the initial position of the weight is not stable, and there is a possibility that the weight and the output member are not properly engaged.

Therefore, it is a technical object of the present invention to reduce the frictional force generated at the contact position at the initial position and to stabilize the initial position.

[0008]

[Constitution of the invention]

[0009]

In order to solve the above technical problems, the technical measures taken in the present invention are as follows. The biasing force of the spring is formed on the outer surface of the weight away from the swing center of the weight with respect to the frame. It has a stopper portion that abuts on the frame so as to act in a substantially vertical direction and holds the weight at the initial position before the swinging operation by the impact.

[0010]

According to the above technical means, the swing motion of the weight is resisted by the urging force of the spring, and the stopper portion and the frame apart from the swing center of the weight come into contact with each other. It will be held at the initial position before the rocking motion due to impact. As a result, the urging force of the spring acts on the abutting portion substantially perpendicularly to the frame, so that the weight is prevented from sticking due to the frictional force generated at the abutting portion at the initial position.
Further, since the stopper portion is formed on the outer surface of the weight, the offset between the weight and the stopper portion is eliminated and the positional accuracy with respect to the weight is improved. Yotsutte
The initial position is stabilized.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, the sensing mechanism 1 is composed of a frame 2, a weight 3, a firing lever 4 and a spring 5.

The weight 3 has a rectangular shape having flat surfaces 3c and 3d, and is swingably supported by a pin 6 at a position offset from the center of gravity thereof. The weight 3 is formed with a semi-circular cam portion 3 a that engages and disengages with the firing lever 4. In addition, the weight 3 has a stopper portion 3 which will be described later and comes into contact with the smooth surface 2a of the frame 2.
b is integrally formed. Fire lever 4
Is rotatably supported on the frame 2 by a pin 7 in a cantilever state, and its tip is an engaging portion 4a that engages with and disengages from the cam portion 3a. Further, the fire lever 4 has a shock-proof safety system (not shown) due to its pivoting operation.
A firing pin 4b that collides with the detonator 8 is formed. The engagement and disengagement between the cam portion 3a and the engaging portion 4a is performed by the swing motion of the weight 3, and the cam portion 3a and the engaging portion 4a are engaged and disengaged.
Due to the engagement with a, the rotation of the firing lever 4 in the direction in which the firing pin is projected, that is, the rotation in the operating direction is restricted. The spring 5 is wound around the pin 7 and has one end 5a locked to the frame 2 and the other end 5b locked to the firing lever 4. Thus, the urging force of the spring 5 acts to rotate the firing lever 4 in the direction in which the firing pin 4b is projected, and the weight 3 is engaged through the engagement between the engagement portion 4a and the cam portion 3b. Will act to resist the swinging motion of the.

The stopper portion 3b is a flat surface 3c of the weight 3.
The smooth surface 2a of the frame 2 is a smooth surface integrally formed apart from the swing center (pin 6) as much as possible.
It is possible to contact with. The contact between the stopper portion 3b and the smooth surface 2a is caused by the spring 5 as shown in FIG.
The urging force F of is applied to this contact portion in a state of being substantially perpendicular to the smooth surface 2a and the stopper portion 3b. Therefore, it becomes difficult for the urging force F to act in the direction of fixing the weight 3 (the component force F1 of the urging force F in the horizontal direction).
That is, the smooth surface 2a between the smooth surface 2a and the stopper portion 3b
The frictional force generated by the slight biting deformation of the smooth surface 2a due to the contact between the flat surface 2a and the stopper portion 3b is small.

The sensing mechanism 1 thus constructed is housed in the case 9. The cam mechanism 10 provided on the bottom wall of the case 9 comes into contact with the flat surface 3d of the weight 3 to restrict the swinging movement of the weight 3 to prevent malfunctions during assembly to a structure such as a vehicle. It is a safety mechanism to prevent.

Next, the operation will be described.

FIG. 1 shows an initial state in which the turning lever 4 is restricted by the weight 3 against the biasing force of the spring 5 by the engagement of the cam portion 3a and the engaging portion 4a. The weight 3 has a cam portion 3a and an engaging portion 4a.
The oscillating motion is resisted by the biasing force of the spring 5 through the engagement with and the smooth surface 2a and the stopper portion 3b are in contact with each other and held at the initial position.

In this state, an impact G of a predetermined value or more
(Impact G that exceeds the urging force of the spring 5)
Is input, the weight 3 swings around the pin 6 against the biasing force of the spring 5 as shown in FIG.
At this time, since the swing center of the weight 3 is offset from the center of gravity, the moment of inertia of the weight 3 acts on the swing motion of the weight 3, so that the weight 3 has an instantaneous impact G of a predetermined value or more. In this case, the swinging operation is not performed, and the swinging operation is performed only by the impact G having a predetermined value or more that is continued for a certain time. Therefore, the shock sensing performance of the device is improved. The swinging movement of the weight 3 causes the cam portion 3a to move.
Rotates, the engagement between the cam portion 3a and the engagement portion 4a is released, and the firing lever 4 rotates about the pin 7 by the urging force of the spring 5. As a result, the firing pin 4b is projected and collides with the detonator 8, and as a result, the shock resistance sensing system is activated.

As described above, the weight 4 has a smooth surface and a stopper portion 3b which is separated from the swing center (pin 6) of the weight 4 by the swinging movement of the weight 4 being resisted by the biasing force of the spring 5. By contacting with 2a, it is held at the initial position. As a result, the biasing force of the spring 5 acts on the contact portion in a state of being substantially vertical to the stopper portion 3b and the smooth surface 2a, and the weight 3 due to the frictional force generated at the contact portion at the initial position. Of the weight 3 to the frame 2 is avoided.
The reliable operation of is guaranteed. Further, since the stopper portion 3b is formed integrally with the flat surface 3c which is the outer surface of the weight 3,
The offset between the weight 3 and the stopper portion 3b is eliminated, and the positional accuracy with respect to the weight 3 is improved. Therefore, the initial position of the weight 3 is stabilized, and reliable engagement between the cam portion 3a and the engaging portion 4a is guaranteed.

[0020]

According to the present invention, the weight is oscillated by the urging force of the spring, and the stop portion of the weight distant from the oscillating center of the weight comes into contact with the frame. It will be held at the initial position before the rocking motion due to impact.

Therefore, the urging force of the spring acts on the abutting portion in a direction substantially perpendicular to the frame,
It is possible to prevent the weight from being fixed to the frame due to the frictional force generated at the contact portion at the initial position. Thereby, the weight can be reliably operated by the impact.
Further, since the stopper part is formed on the outer surface of the weight, the offset between the weight and the stopper part is eliminated, the deformation of the stopper part due to the torsional stress can be prevented, and the stopper part is not attached to the weight and the position relative to the weight is eliminated. The accuracy can be improved. Therefore, the initial position of the weight 2 is stabilized, the weight and the output member can be reliably engaged with each other at the initial position, and the performance of the device can be improved.

[Brief description of drawings]

FIG. 1 is a plan view of an impact sensing device according to the present invention before operation.

FIG. 2 is a plan view after the operation of the impact sensing device according to the present invention.

FIG. 3 is a detailed explanatory view of a main part of the impact sensing device according to the present invention.

[Explanation of symbols]

 2 frame 3 weight 4 output member (firing ring lever) 5 spring 3b stopper part

Claims (1)

[Claims] 1. A frame, a weight swingably supported by the frame and swinging by an impact of a predetermined value or more, and a weight rotatably supported by the frame and engaged with the weight. An output member, which is disengaged from the weight to be rotated by a swinging motion, and the output member, which is disposed between the frame and the output member, is rotated by its biasing force. In an impact sensing device having both a spring for resisting the swinging motion of the weight, an urging force of the spring formed on an outer surface of the weight distant from the swinging center acts in a direction substantially perpendicular to the frame. An impact sensing device having a stopper portion that abuts on the frame and holds the weight at an initial position before the swinging motion by impact.