JPH09156459A - Shock sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shock sensor capable of accurately detecting the acceleration generating a danger regardless of direction angle and capable of being simply formed at a low cost. SOLUTION: A shock sensor main body 200 is constituted of a nonconductive base 24 having a boss 24b protruded in one axis direction at the center portion, the first conductive contact piece section 31 having an insertion hole 31b inserted with the boss 24b in no contact, a hanging bell-like conductive cap section 23 covered on the apex of the boss 24b inserted into the insertion hole 31b, a spring 25 fitted to the apex side periphery of the conductive cap section 23 on one end side of the spring 25 as a conductive excitation section, and the second conductive contact piece section 32 fixed on the other end side of the spring 25 to press it. When a local section of the conductive cap section 23 receives a shock capable of generating the prescribed acceleration or above in an optional direction on the plane perpendicular to one axial direction, it is displaced against the exciting force of the spring 25 and brought into contact with the conductive contact piece section 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact sensor used for an occupant protection device mounted on a moving body such as an automobile, and more particularly, it is based on acceleration generated when an impact such as a collision is received. The present invention relates to an impact sensor having a detection mechanism portion in which a conductive contact medium disposed between a pair of conductive contact piece portions is brought into contact with each conductive contact piece portion via a conductive biasing portion.

[0002]

2. Description of the Related Art In recent years, a moving body such as an automobile is equipped with an occupant protection device such as an air bag system for protecting the occupant in the event of a collision. An impact sensor is used as a detection unit for detecting acceleration that sometimes occurs.

FIG. 4 is an exploded perspective view showing an example of the basic structure of the impact sensor body (detection mechanism portion) 100. This shock sensor body 100
Is a diameter of a conductive steel ball B as a conductive contact medium between a base 12 having a non-through storage hole 12a for storing a magnet (rare earth permanent magnet) M and one conductive contact piece 21. A spacer 11 having a through hole 11a opened with a larger diameter and a conductive contact piece 22 having a hemispherical shell-shaped concave portion 22b for accommodating the conductive steel ball B are arranged. It is configured by combining each part of.

That is, in the main body of the shock sensor 100, the locking projections 12b provided at the four corners of the base 12 in the state where the magnet M is housed in the non-through hole 12a are provided at the four corners of the other parts, respectively. By passing through the locking through hole and caulking the exposed portion of the locking convex portion 12b protruding from the surface of the conductive contact piece portion 21 to fix each portion, as shown in the cross-sectional side view of FIG. Steel ball B is attracted by the magnetic force of magnet M, and through hole 11 of spacer 11
The concave portion 22b (the magnet M
On the side, it is assembled so that it is in contact with the convex portion).

In this shock sensor body 100, the conductive steel ball B is in contact with the concave portion 22b of the other conductive contact piece 22 in the steady state (when no shock is detected), but when a collision is received. When such an impact is detected, if the acceleration generated at that time becomes equal to or higher than a predetermined value (equal to or higher than a value at which safety of the occupant is regarded as dangerous), the conductive steel ball B as shown by a dotted line in FIG.
Are released from being restrained by the magnetic force of the magnet M, and each conductive contact piece 2 in the through hole 11a of the spacer 11 is released.
1 and 22, each conductive contact piece 21,
Touch 22. Circuit connecting terminal portions 21a, 2 provided at one ends of the conductive contact piece portions 21, 22 respectively.
Reference numeral 2a is connected to a detection circuit, and when the conductive steel ball B is brought into contact with the detection circuit, the detection circuit is brought into a conductive state, so that the detection circuit detects acceleration that is dangerous to an occupant. That is,
The connection between the conductive steel ball B and the magnet M here is designed to be released by a load of a predetermined acceleration or more, and the mass (weight) of the conductive steel ball B related to the bonding force.
And the magnetic force of the magnet M are set to predetermined values.

FIG. 6 shows a schematic structure of a detection circuit (a sensor circuit including the shock sensor main body 100) of a detecting section when the shock sensor main body 100 is used as a shock sensor. This detection circuit is configured by connecting the shock sensor body 100 and the capacitor C in parallel to the controller 101 via the reset switch R-SW. Here, the reset switch R-SW is immediately returned to the original position after the conductive steel ball B in the shock sensor body 100 receives a load of a predetermined acceleration or more and is momentarily contacted with the conductive contact piece portions 21 and 22. Since it is configured to return, it is provided to receive electric charge from the capacitor C and self-maintain electrical continuity according to a setting instruction from the controller 101 once a predetermined acceleration is detected.

Incidentally, here, an impact sensor having a detection structure in which a conductive steel ball is brought into conductive contact with a conductive contact piece has been described, but as a well-known technique related to this, there is known a Japanese Utility Model Laid-Open No. 4-2439. Impact detection device disclosed in Japanese Patent Laid-Open No. 6-80059, vehicle sensitive mechanical contactor disclosed in Japanese Patent Laid-Open No. 6-80059, inertial sensor for activating a vehicle passenger restraint device disclosed in Japanese Patent Laid-Open No. 6-1865010, and the like Is mentioned.

[0008]

In the case of the impact sensor described above, when it is used as an air bag system (also called a G sensor in this case), a normal automobile normally operates at a speed of 22.
It is designed to detect the acceleration generated at the time of a head-on collision within an angle range of ± 15 degrees with respect to the traveling direction under the condition that the vehicle is traveling at a distance of more than 10 km, so that it is possible to detect other accelerations such as side and back surfaces. The impact (acceleration that causes danger) received from the direction cannot be accurately detected, and there is a problem that the safety as an occupant protection device is not sufficiently ensured.

Further, in the case of the above-mentioned impact sensor main body, since the rare earth permanent magnet (magnet), which has a large number of parts and is high in cost, is used, the assembly and management of the parts are complicated, and the sensor itself becomes a single unit. There is also the problem that the product price will become expensive.

The present invention has been made to solve such a problem, and its technical problem is to be able to accurately detect a dangerous acceleration without restricting a direction angle and to be simple and inexpensive. Another object of the present invention is to provide a shock sensor that can be configured as described above.

[0011]

According to the present invention, a non-conductive base having a boss projecting uniaxially in a central portion and a first conductive hole having an insertion hole for inserting the boss in a non-contact manner. Conductive contact piece, a bell-shaped conductive cap that covers the top of the boss inserted in the insertion hole, a conductive urging part that is attached to one end around the top of the conductive cap, and A detecting mechanism portion including a second conductive contact piece portion mounted and fixed to the other end side of the conductive biasing portion while the conductive biasing portion is being pressed; The first conductive contact piece is not in contact with the first conductive contact piece by being biased by the biasing portion, and the local part is brought into contact with the first conductive contact piece when an impact capable of causing a predetermined acceleration or more is received. A shock sensor is obtained.

In the vehicle impact sensor in which the detection mechanism section is provided in the vehicle, it is preferable that the detection mechanism section is provided at the center of gravity of the vehicle.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The impact sensor of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an exploded perspective view showing the basic structure of an impact sensor body 200 according to an embodiment of the present invention. The impact sensor main body 200 (detection mechanism portion) has a non-conductive base 24 having a boss 24b protruding in a uniaxial direction at a central portion thereof, and a first insertion hole 31b for inserting the boss 24b in a non-contact manner. The conductive contact piece portion 31 and the boss 24 in a state of being inserted into the insertion hole 31b.
Bell-shaped conductive cap portion 23 that is placed on the top of b
A spring 25 as a conductive urging portion, one end side of which is attached around the top side of the conductive cap portion 23, and a second spring 25 which is attached and fixed to the other end side of the spring 25 while pressing the spring 25. And the conductive contact piece portion 32 of FIG.

In this impact sensor body 200, the circuit connecting terminal portion 31a of the first conductive contact piece portion 31 and the circuit connecting terminal portion 32a of the second conductive contact piece portion 32 are not shown in the drawing. It is designed to be connected to.

The main body of the shock sensor 200 is a base 24.
The locking projections 24a provided at the four corners of the base 24 are passed through the locking through holes provided at the four corners of the respective parts, and the boss 24b of the base 24 is inserted into the insertion hole 31b of the first conductive contact piece 31. Then, the first conductive contact piece portion 31 is placed on the base 24, the top of the boss 24b protruding from the insertion hole 31b is covered with the conductive cap portion 23, and one end of the spring 25 is attached to the conductive cap portion 23. After the other end side of the spring 25 is pressed by the second conductive contact piece portion 32 after being mounted on the periphery of the top side of the above, the locking convex portion 24a protruding from the surface of the second conductive contact piece portion 32 It is assembled by caulking the exposed part of and fixing each part.

In this shock sensor body 200, in a steady state (when no shock is detected), the conductive cap portion 23 is urged by the spring 25 with the top of the boss 24b as a fulcrum, as shown in FIG. 2 (a). It is held and is in a non-contact state with the first conductive contact piece portion 31, but at the time of impact detection such as when a collision occurs, the acceleration generated at that time is equal to or more than a predetermined value (safety of the occupant is dangerous. 2B), the conductive cap portion 23 springs due to acceleration (due to the inertial force received by the conductive cap portion 23) generated in the illustrated α direction, for example, as shown in FIG. 2B. Displaced by overcoming the urging force of 25,
The local portion contacts the first conductive contact piece portion 31. At this time, the spring 25 is elastically deformed, but in each of the conductive contact piece portions 31 and 32, the circuit connecting terminal portion 31 is formed.
a and 32a are connected to the detection circuit, and when the conductive contact piece portions 31 and 32 are brought into contact with each other, the detection circuit becomes conductive, so that the detection circuit detects acceleration that is dangerous to the occupant.

By the way, the shock sensor main body 200 here is used.
In the steady state, the bottom portion of the conductive cap portion 23 is disposed at a substantially predetermined distance from the first conductive contact piece portion 31, so that the boss 24b extends in the uniaxial direction. When, for example, a shock greater than a predetermined acceleration is applied in an arbitrary direction on a vertical surface, the conductive cap portion 2
The local part of 3 is brought into contact with the first conductive contact piece part 31. That is, the holding of the conductive cap portion 23 by the top portion of the boss 24b and the spring 25 is released by a load of a predetermined acceleration or more, and the conductive steel ball B related to the holding force is released. The mass (weight) and the biasing force (spring constant) of the spring 25 are set to predetermined values.

Therefore, such an impact sensor body 200
When used in an airbag system or the like, which is an occupant protection device for a vehicle, can not only detect a shock (acceleration causing danger) in a frontal collision or the like in the traveling direction, but also other side or back surfaces. It is possible to accurately detect the impact received from the direction.

FIG. 3 shows a preferred example in which the impact sensor body 200 is installed in a vehicle. The impact sensor main body 200 does not detect an impact in the uniaxial direction described above, that is, in the extending direction of the boss 24b (corresponding to the height direction of the vehicle) in FIGS. 2A and 2B,
Since it is a highly sensitive object that can detect an impact in an arbitrary direction on a plane perpendicular to this, when it is installed in a vehicle, as shown in FIG. The detection mechanism section may be provided in the CG.

Incidentally, also in this shock sensor main body 200, the local portion of the conductive cap portion 23 is immediately returned to its original position after being contacted with the first conductive contact piece portion 31 for a moment due to a load greater than a predetermined acceleration. Because it is supposed to return,
When the detection unit is configured as an impact sensor, it is desirable that the detection circuit (sensor circuit) described in FIG.

[0022]

As described above, according to the present invention, the conductive cap portion as a medium for conductive contact is provided between the first and second conductive contact piece portions and the top portion of the boss from the base and the conductive cap portion. When it is held by a conductive urging portion attached to the conductive contact piece portion of 2, and is subjected to a shock of a predetermined acceleration or more in an arbitrary direction on a plane perpendicular to the uniaxial direction, which is the extending direction of the boss. Since the main part (detection mechanism part) of the shock sensor main body is configured so that the local part of the conductive cap part is brought into contact with the first conductive contact piece, The detection can be performed in a free direction and with high sensitivity, unlike the conventional case. In addition, in the case of this shock sensor body, since the number of parts is small and expensive rare earth permanent magnets are not used, the parts can be easily assembled and managed, and the product price of the sensor alone can be cheap. There is. Furthermore, if this detection mechanism is used as a vehicle impact sensor by arranging it at the center of gravity where the vibration of the vehicle is the smallest, in addition to detecting impacts (acceleration causing danger) from a frontal collision, etc. Since it is possible to accurately and highly accurately detect the impact received from other directions, the safety as an occupant protection device can be sufficiently ensured as never before. As a result,
For example, in the case of a passenger protection device, when detecting impacts in various directions, it is possible to improve safety by using other visual functions such as hazard lighting, lock release, seat belt release, and an emergency drive function together. Become.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a basic structure of an impact sensor body according to an embodiment of the present invention.

2A and 2B are shown for explaining the operation of the main part of the shock sensor body shown in FIG. 1, in which FIG. 2A is for a steady state (when no shock is detected), and FIG. 2B is for shock detection. Is.

FIG. 3 is a perspective view of a vehicle shown for explaining a preferred arrangement when the impact sensor main body shown in FIG. 1 is used in the vehicle.

FIG. 4 is a perspective view showing an exploded basic configuration of an example of a conventional impact sensor body.

5 is a cross-sectional side view of the shock sensor body shown in FIG. 4 in an assembled state.

FIG. 6 shows a schematic configuration of a detection circuit (sensor circuit) of a detection unit including the impact sensor main body described in FIGS. 4 and 5.

[Explanation of symbols]

 11 Spacer 11a Through hole 12,24 Base 12a Non-through storage hole 12b, 24a Locking convex part 21, 22, 31, 32 Conductive contact piece part 21a, 22a, 31a, 32a Circuit connecting terminal part 22b Recess 23 Conductive Cap part 24b Boss 25 Spring 31b Insertion hole 100,200 Impact sensor body 101 Controller B Conductive steel ball C Capacitor M Magnet R-SW Reset switch

Claims (2)

[Claims] 1. A non-conductive base having a boss projecting uniaxially in a central portion, a first conductive contact piece portion having an insertion hole for inserting the boss in a non-contact manner, and the insertion hole. A bell-shaped conductive cap portion that covers the top portion of the boss in a state of being inserted into the boss, a conductive biasing portion having one end side mounted around the top portion of the conductive cap portion, and a conductive biasing portion of the conductive biasing portion. A detection mechanism portion including a second conductive contact piece portion mounted and fixed to the other end side in a state of pressing the conductive biasing portion, wherein the conductive cap portion is formed by the conductive biasing portion. It is urged to be in non-contact with the first conductive contact piece, and to be brought into contact with the first conductive contact piece when the local portion receives a shock that can generate a predetermined acceleration or more. Characteristic impact sensor. 2. A vehicle impact sensor comprising the detection mechanism section according to claim 1 disposed in a vehicle, wherein the detection mechanism section is disposed at a center of gravity of the vehicle. Impact sensor.