JPH10123170A - Collision detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize a collision detector. SOLUTION: Sheet-shaped terminal contacts 5 and 6 are subjected to resin insert formation into a seat part 10 of a base 1, fixed contact parts 51 and 61 are exposed in the base 1, both edges protrude toward the outside of the base 1. A disk-shaped spring 2 has a movable contact part 21 that is located at nearly a center, a peripheral edge part 24 that is located around the movable contact part 21, and leaf spring parts 22 and 23 for connecting them, has a specific gap between the movable contact part 21 and the fixed contact parts 51 and 61, and is arranged at a seat part 11 of the base 1. A weight 3 is housed slidably between the spring 2 and the lid 4 in the base 1 while its projecting part 31 is arranged at the side of the spring 2, and is elastically energized at the side of the lid 4 by the spring 2. A projecting part 13 is formed at four corners of the peripheral edge part of the opening 12 of the base 1, the projecting part 13 is inserted into a hole provided at the lid 4, and heat caulking is performed, thus fixing the lid 4 to the base 1 so that an opening 12 is covered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collision detecting device which mechanically conducts between contacts by a deceleration acting upon a collision and detects a collision based on a conduction state between the contacts.

[0002]

2. Description of the Related Art Conventionally, for example, a collision detection device for detecting a collision of a vehicle has a structure shown in FIG. 6 (Japanese Patent Application Laid-Open No. 3-27464). This collision detection device 81
The mass 82 moves toward the main spring 88 while the mass 82 slides against the inner peripheral surface of the case body 83a against the urging force of the main spring 88 due to the impact force when the vehicle collides.
When the moving amount of the mass 82 exceeds the gap S, the spring load of the spring 89 becomes a contact contact load,
The movable contact 86 comes into contact with the respective contact portions 84a, 85a of the fixed contact fixed to the contact case 83b, and the connection between the external connection terminal portions 84b, 85b becomes conductive, and the state changes between the terminal portions 84b, 85b. To detect a collision.

[0003]

However, in recent years,
As the components mounted on the substrate have been reduced in size and surface mounted, the collision detection device 81 has a problem that the thickness in the collision detection direction is large, and the market requirements for mounting on the substrate cannot be sufficiently satisfied.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to reduce the size of a collision detection device and to realize a collision detection device that can be easily mounted on a substrate in view of the above problems.

[0005]

According to the present invention, in order to solve the above-mentioned problems, a seat is provided on a housing.
A pair of contact members is provided, and a plate-shaped elastic member is provided with a predetermined gap provided between the pair of contact members.
The opening of the housing is covered with a lid member, and the weight body urged by the elastic member is in contact with the lid member in the housing. The collision detection device is configured in this manner, and when an acceleration equal to or more than a predetermined value acts, the weight body moves toward the pair of contact members against the urging force of the elastic member,
The pair of contact members and the elastic member are brought into contact with each other to establish conduction between the pair of contact members. A collision is detected by the conduction between the pair of contact members. Since this collision detection device has a plate-shaped elastic member, the thickness in the collision detection direction can be reduced, and the size of the collision detection device can be reduced. Conventionally, two springs were used.
By reducing the required number of elastic members by making the present invention, by having the elastic member also have a contact function,
The number of parts can be reduced, and an inexpensive collision detection device can be realized. Also, by contacting the weight with the lid member, the distance between the pair of contact members and the opening and the thickness in the moving direction of the weight can be used to easily make the pair of contact members elastic. The gap between the members can be determined.

According to the second aspect of the present invention, the elastic member is provided with the movable contact portion substantially at the center thereof, and the peripheral portion is provided around the movable contact portion. The peripheral portion is arranged at a predetermined position of the housing, and the movable contact portion and the peripheral portion are connected by a leaf spring portion that generates an urging force. With such a configuration of the elastic member, the weight body can be elastically urged toward the lid member with a small displacement, and the movable contact portion can be elastically displaced with the movement of the weight body toward the contact member. .

According to the third aspect of the present invention, the spring constant is adjusted by adjusting the width and length of the semi-arc by providing the semi-circular plate spring around the movable contact. It can be set arbitrarily.

According to the fourth aspect of the present invention, a pair of leaf springs are provided symmetrically around the movable contact in a semi-circular shape, and the biasing force of the leaf spring against the weight body is substantially reduced. In addition to acting uniformly, the surface of the movable contact portion can be displaced substantially perpendicularly to the moving direction.

According to the fifth aspect of the present invention, one end is connected to the movable contact portion, and the other end is a free end provided on the elastic member. When the elastic member comes into contact with the pair of contact members while being elastically urged to the seat portion, energy is absorbed by the elastic deformation of the elastic member. As a result, the contact between the elastic member and the pair of contact members is brought about. The reaction force at the time can be reduced, the holding time at the time of contact with the contact can be lengthened, and a stable output can be obtained.

According to the sixth aspect of the present invention, the buffer portion is provided in a semicircular shape around the movable contact portion,
By adjusting the width and length of the semicircular arc, the spring constant of the buffer can be arbitrarily set.

According to the seventh aspect of the present invention, a pair of buffer portions are provided in a semicircular arc symmetrically around the movable contact portion so that the biasing force of the buffer portion to the seat portion can be substantially uniform. This allows the energy to be absorbed almost uniformly at the time of contact with the seat portion, so that the parallelism of the movable contact portion can be improved.

According to the eighth aspect of the present invention, in the lid member, the height of the dimension adjusting section is adjusted by providing the convex dimension adjusting section on the inner surface in contact with the weight body. Thereby, the gap between the pair of contact members and the elastic member can be adjusted more accurately.

According to the ninth aspect of the present invention, the pair of contact members are elastically deformed at the time of contact with the elastic member, thereby reducing the reaction force at the time of contact between the elastic member and the pair of contact members. In addition, the holding time at the time of contact with the contact can be lengthened, and a stable output can be obtained.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on specific embodiments. FIG. 1 is a schematic diagram showing a configuration of a collision detection device 100 according to a specific embodiment of the present invention. The collision detection device 100 is used to activate an occupant protection device such as an airbag device of a vehicle. FIG.
FIG. 1C shows a front view of the collision detection device 100, and FIG.
1B shows a left side view thereof, and FIG. 1D shows a bottom view thereof. 1A shows a sectional view taken along the line AA in FIG. 1C, and FIG. 1E shows a sectional view taken along the line BB in FIG. 1C. FIG. 2 is an assembled sectional view of the collision detection device 100, and FIG.
0 shows an assembled state and a state at the time of deceleration operation.

As shown in FIG. 1, a base (housing) 1 made of a resin material is formed in a box shape, and seats 10 and 11 are provided on the bottom surface.
, And convex portions 13 (see FIG. 2) are provided at four corners of the peripheral end surface of the opening. Copper-made plate-shaped terminal contacts (contact members) 5, 6 are resin-insert molded into the seat 10, and both ends of the terminal protrude outside the base 1. The terminal contacts 5 and 6 have fixed contact portions 51 and 61 at the centers thereof, respectively.
1 has a gold-plated contact surface with the spring 2,
It is narrower than both ends, is formed in a convex shape toward the inside of the base 1, and is exposed. The fixed contact portions 51 and 61 are X
It is oriented in a direction substantially perpendicular to the direction.

The spring (elastic member) 2 is a disc-shaped leaf spring as shown in FIG. 2, and its material is made of copper. The spring 2 has a circular movable contact portion 21 at the center, and two semicircular plate spring portions 22 and 23 are provided symmetrically between the peripheral edge portion 24 and the movable contact portion 21. ing. Fixed contact portions 51 and 6 of movable contact portion 21
1 is gold-plated. This spring 2
Is arranged on the seat 11 of the base 1.

The weight (weight body) 3 is formed in a substantially prismatic shape by machining a copper material, has a convex portion 31 on one surface, and the convex portion 31 is disposed on the spring 2 side, and It is slidably housed inside. Convex part 3 of weight 3
1 is in contact with the movable contact portion 21 of the spring 2 and is elastically biased toward the lid 4. The lid (lid member) 4 is made of a metal material and is formed in a square plate shape.
3, holes 41 are provided. This lid 4
Is fixed to the base 1 by the heat staking of the convex portion 13 fitted in the hole 41, covers the opening 12 of the base 1,
Weight 3 urged toward lid 4 by spring 2
Holding.

Next, a method of assembling the collision detection device 100 will be described. First, as shown in FIG. 3 (a), the spring 2 is arranged on the seat 11 of the base 1 on which the terminal contacts 5 and 6 are resin-inserted so that the gold plating surface is on the terminal contacts 5 and 6 side. Is done. Thereby, the surface of the spring 2 is substantially orthogonal to the X direction. Then, the weight 3 is stored in the base 1 with the convex portion 31 first. Thereafter, as shown in FIG. 3B, the protrusions 13 of the base 1 are fitted into the holes 41 of the lid 4, and the protrusions 13 are heat caulked to form the opening 1 of the base 1.
The lid 4 is fixed to the base 1 so as to cover the base 2. Thus, the collision detection device 100 is assembled.

At this time, the convex portion 31 of the weight 3 displaces the movable contact portion 21 of the spring 2 toward the fixed contact portions 51, 61 by a predetermined amount, and the movable contact portion 21 and the fixed contact portion 51,
61 is a predetermined gap between contacts, for example, 0.2 to 0.5 m
m Set to ± 0.05mm. Depending on the amount of displacement of the movable contact portion 21 toward the fixed contact portions 51 and 61, the leaf spring portion 22,
The weight 3 becomes the lid 4
Elastically biased to the side. The load of this elastic bias is a set load, and when the load acting on the spring 2 from the weight 3 is equal to or less than the set load, the movement of the weight 3 is prevented. Therefore, the movable contact portion 21 and the fixed contact portions 51 and 61 are prevented from coming into contact with each other due to the deceleration caused by a collision other than the vibration. The set load can be set to an arbitrary value by adjusting the amount of displacement of the movable contact portion 21 at this time. Further, the spring constant of the spring 2 can be arbitrarily set by adjusting the width and length of the leaf spring portions 22 and 23. When a load exceeding the set load acts on the spring 2 from the weight 3, the movable contact 21
Is displaced toward the fixed contact portions 51 and 61, and when a predetermined load value is reached, the movable contact portion 21 and the fixed contact portions 51 and 61 come into contact with each other. It becomes conductive (see FIG. 3C).

Next, the operation of the collision detection device 100 will be described. If a collision occurs while the vehicle is moving in the X direction, the deceleration acts, and the weight 3 receives acceleration in the X direction and attempts to move in the X direction. When the load acting on the spring 2 from the weight 3 exceeds the set load, the weight 3 resists the urging force of the spring 2 and
It is displaced to the terminal contacts 5 and 6 side. Due to the displacement of the weight 3, the movable contact portion 21 bends in the X direction,
When the distance between the movable contact portion 21 and the fixed contact portions 51, 61 is reduced and the load acting on the spring 2 from the weight 3 reaches a predetermined value, the movable contact portion 21 and the fixed contact portions 51, 61
Is in contact with The level of the deceleration acting at this time is the collision detection level, and the collision is determined by adjusting the maximum displacement of the movable contact portion 21 in FIG. 3C, that is, the maximum deflection amount of the leaf spring portions 22 and 23. The detection level can be set arbitrarily. As a result, the terminal contacts 5 and 6 conduct through the movable contact portion 21, and the conduction state of the terminal contacts 5 and 6 is output to the outside as a collision detection signal. Then, the occupant protection device is activated based on the collision detection signal. The occupant protection device includes an airbag device corresponding to a collision from the front, a side airbag device corresponding to a collision from the left and right, and a seat belt pretensioner.
0 is used for a safing sensor, a crash sensor, and the like for activating these occupant protection devices.

In addition, at the time of deceleration other than the collision, for example, at the time of sudden braking or vibration, the weight 3 does not act on the spring 2 beyond the set load. Without this, the movable contact part 21 does not contact the fixed contact parts 51, 61. Therefore, the conductive state is not established between the fixed contact portions 51 and 61, so that no collision is detected. As described above, the activation of the occupant protection device can be prevented except at the time of the collision, and the reliability of the collision detection device 100 can be ensured.

In the above collision detection device 100, since the elastic member is provided with the plate-shaped spring 2, the thickness of the collision detection device 100 can be reduced and its size can be reduced. In the present embodiment, the physique of the collision detection device 100 is 8 mm ×
8mm x 5mm, approx. 1/10 of conventional physique
I was able to achieve the physique. Therefore, the collision detection device 100 can be easily mounted on a printed circuit board. Further, the number of springs to be used can be reduced, the number of parts can be reduced, and the collision detection device 100 which is less expensive can be used.
Has become possible. The gap between the contacts between the movable contact portion 21 and the fixed contact portions 51 and 61 is the fixed contact portion 5.
Since it can be determined by the size between the first and the 61 and the opening 12 and the thickness of the weight 3 in the sliding direction, the gap between the contacts can be easily set.

In the above embodiment, the two leaf springs 2 are located between the movable contact 21 and the peripheral edge 24 of the spring 2.
2 and 23 are provided so as to be elastically urged by the leaf spring portions 22 and 23 in accordance with the displacement of the movable contact portion 21. However, as shown in FIG. May be connected by a single semi-circular plate-like leaf spring portion 26, and a semi-circular buffer portion 25 having a free end may be provided on the movable contact portion 21 so as to face this leaf spring portion 26. With the configuration shown in FIG. 4, since the movable contact portion 21 is fixed to the peripheral portion 24 at one place by the leaf spring portion 26, when the movable contact portion 21 contacts the weight 3, A portion excluding the peripheral portion 24 is arranged to be inclined with respect to the peripheral portion 24. When the weight 3 is displaced toward the fixed contact portions 51 and 61 by the action of the deceleration, the buffer portion 25 comes into contact with the seat portion 10 of the base 1 and is elastically deformed, and the contact gap is narrowed. And the fixed contact portions 51 and 61 come into contact with each other. Due to the energy absorbing action of the buffer 25, the movable contact 21 and the fixed contact 51,
The reaction force at the time of contact with the contact member 61 is weakened, the contact holding time is lengthened, and a more stable detection signal can be obtained. or,
By adjusting the width and length of the leaf spring portion 26, the spring constant of the spring 201 can be arbitrarily set, and the set load and the collision detection level can be arbitrarily set. In addition, by adjusting the width and length of the buffer 25, the spring constant of the buffer 25 can be set arbitrarily, the amount of energy absorption at the time of contact with the seat 10 is made variable, and the contact holding time is adjusted. be able to.

In the spring 201 shown in FIG. 4, the movable contact portion 21 is provided with one leaf spring portion 26 and one buffer portion 25. However, as shown in FIG. A pair of buffer portions 27a, 2
7b and leaf spring portions 28a and 28b are provided.
2 may be configured. Thus, when the movable contact portion 21 is displaced toward the fixed contact portions 51 and 61 with the displacement of the weight 3, the buffer portions 27a and 27b are moved to the seat portion 10 of the base 1.
4, elastically deforms and absorbs energy, so that the reaction force at the time of contact between the movable contact portion 21 and the fixed contact portions 51 and 61 is weakened, the contact holding time becomes longer, and the spring 201 shown in FIG. The same effect can be obtained. Further, in the spring 202, since the shock-absorbing portions 27a and 27b are provided in a rotationally symmetric manner, the biasing force to the seat portion 10 is made to act almost uniformly, the energy absorption can be made almost uniform, and the parallelism of the movable contact portion 21 can be improved. It is possible to secure. Also in this spring 202, by adjusting the width and length of the leaf spring portions 28a and 28b, their spring constants can be arbitrarily set, and the set load and the collision detection level can be easily adjusted. Further, by adjusting the width and length of each of the buffer portions 27a and 27b, their spring constants can be arbitrarily set, and the amount of energy absorption by the buffer portions 27a and 27b can be easily adjusted.

In FIGS. 4 and 5, when the movable contact portion 21 and the fixed contact portions 51 and 61 are in contact with each other, the buffer portion contacts the seat portion 10 of the base 1 and is elastically deformed to absorb energy. Thus, the contact holding time may be lengthened, but the contact holding time may be lengthened by elastically deforming the fixed contact portions 51 and 61 at the time of contact with the movable contact portion 21. Further, in the above-described embodiment, the plate spring is used as the elastic member. However, a disc spring or a membrane spring may be used as the elastic member.

In the above embodiment, the terminal contacts 5 and 6 are fixed to the base 1 by resin insert molding. However, even if the terminal contacts 5 and 6 are fixed to the base 1 by another method such as bonding or screwing. Good.
In the above-described embodiment, the lid 4 and the base 1 are fixed by heat caulking of the convex portion 13 provided on the base 1. However, the lid 4 and the base 1 are fixed by another method such as adhesion or welding.
And may be fixed. Further, in the above embodiment, the material of the lid 4 is metal, but the material of the lid 4 may be a resin material. Further, although the material of the spring 2 and the terminal contacts 5 and 6 is copper, other materials may be used as long as they are metal materials. Further, although the material of the weight 3 is copper, another metal may be used, and a nonmetallic material may be used as long as a necessary inertial force can be obtained. In the above embodiment, the weight 3 is urged toward the lid 4 by the spring 2,
Although the weight 3 is held to obtain a desired gap between the contacts, it is difficult to keep the gap between the contacts within a desired allowable range (± 0.05 mm) due to the dimensional variation of the base 1. May be configured such that a convex dimension adjusting portion is formed on the inner side surface. By finely adjusting the height of the dimension adjusting portion, it is possible to change the position of the tip of the convex portion 31 of the weight 3, to eliminate the influence of the dimensional variation of the base 1, and to obtain the desired contact gap (0.2 to 0.5mm
± 0.05mm).

As indicated above, according to the present invention,
By providing the plate-shaped elastic member, it is possible to promote the miniaturization of the collision detection device, reduce the number of components, and reduce the cost. Further, a buffer portion is provided on the elastic member, and the buffer portion is elastically deformed when the movable contact portion and the fixed contact portion come into contact with each other, so that the movable contact portion and the fixed contact portion are brought into contact with each other, so that the contact holding time can be lengthened. A stable collision detection signal can be obtained.

[Brief description of the drawings]

FIG. 1 is a structural diagram showing a configuration of a collision detection device according to a specific embodiment of the present invention.

FIG. 2 is an assembly development view showing a configuration of a collision detection device according to a specific embodiment of the present invention.

FIG. 3 is a schematic diagram showing a state change of a collision detection device according to a specific embodiment of the present invention.

FIG. 4 is a perspective view of a collision detection device according to a specific embodiment of the present invention.
The schematic diagram which showed the structure provided one by one.

FIG. 5 is a perspective view of a collision detecting device according to a specific embodiment of the present invention.
FIG. 3 is a schematic diagram showing a configuration provided for each pair.

FIG. 6 is a schematic sectional view showing a configuration of a conventional collision detection device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Base 2,201,202 Spring 3 Weight 4 Lid 5,6 Terminal contact 10,11 Seat part 12 Opening 21 Movable contact part 22,23,26,28a, 28b Leaf spring part 24 Peripheral part 25,27a, 27b Buffer Unit 51, 61 Fixed contact unit 100 Collision detection device

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Seiichi Narita 1-1-1, Showa-cho, Kariya-shi, Aichi Pref.

Claims (9)

[Claims] 1. A collision detection device for detecting an acceleration equal to or higher than a predetermined value by conducting a mechanical contact according to an acceleration received, comprising: a housing having an opening at one end and a seat at the other end; A pair of contact members provided on the seat portion of the housing; a plate-like elastic member provided with a predetermined gap between the pair of contact members; and the opening of the housing A lid member that covers the cover member, and is brought into contact with the lid member by the urging force of the elastic member, and moves toward the pair of contact members against the urging force of the elastic member by the action of an acceleration of a predetermined value or more. A collision detection device, comprising: a weight body that brings the pair of contact members into contact with the elastic member to conduct between the pair of contact members. 2. The movable member, wherein the elastic member is located substantially at the center, is displaced with the movement of the weight body, and is in contact with the pair of contact members. 2. A peripheral part arranged at a predetermined position of a housing, and a leaf spring part for connecting the movable contact part and the peripheral part to generate the urging force.
3. The collision detection device according to claim 1. 3. The device according to claim 1, wherein the leaf spring portion is provided in a semicircular shape around the movable contact portion.
Or the collision detection device according to claim 2. 4. The collision detecting device according to claim 3, wherein a pair of the leaf spring portions are provided symmetrically about a center. 5. The elastic member has a buffer portion having one end connected to the movable contact portion and the other end being a free end, and the buffer portion moves with the movement of the weight body. 5. The pair of contact members and the elastic member come into contact with each other while being elastically biased against the seat portion. 6.
The collision detection device according to any one of the above. 6. The collision detecting device according to claim 5, wherein the buffer portion is provided in a semicircular shape around the movable contact portion. 7. The collision detecting device according to claim 6, wherein a pair of the buffer portions are provided symmetrically about the center. 8. The collision detection device according to claim 1, wherein a convex dimension adjusting portion is provided on the inner surface of the lid member that comes into contact with the weight body. 9. The device according to claim 1, wherein the pair of contact members are elastically deformable when contacting the elastic member.
Or the collision detection device according to claim 2.