JPH07117622A - Sensor for occupant protection device - Google Patents

Abstract

PURPOSE:To provide a sensor for an occupant protection device which can detect a load properly by the sure action of the load to two or more among the sensors arranged pulurally and realize this situation by a simple thin structure. CONSTITUTION:A projection 52 is formed on a holding bracket 44, in a primary sensor 34 and the free end 46B of a sheet spring 46 is in contact therewith. After the elastic deformation of the sheet spring 46 and the conduction of a membrane switch 48, a substantial spring constant of the sheet spring 46 is reduced by coming off of the free end 46B from the projection 52 and the sheet spring 46 can make much larger elastic deformation by a small load. Therefore, two or more primary sensors 34 can detect the load properly and further a moving stroke after the conduction can be largely secured while largely setting the spring constant of the sheet spring 46 and the sensor can be made thin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an occupant protection device sensor which is pressed by a body panel after deformation to operate an occupant protection device provided in a vehicle.

[0002]

2. Description of the Related Art Conventionally, a vehicle equipped with an occupant protection device at the time of a collision, for example, an air bag device for detecting the deceleration of the vehicle at the time of a collision and inflating the back toward the occupant side has been used. . This type of airbag device is generally disposed near the steering wheel of the vehicle or the upper part of the glove box, but in recent years it has been proposed to provide the airbag device on the vehicle door. . Along with this, a sensor for operating the airbag device disposed inside the vehicle door is required.

A sensor using a leaf spring has been proposed as such a sensor. That is, one end of a leaf spring in which the middle portion of a rectangular flat plate is bulged in an arcuate shape is fixed to a plate member by spot welding, and a switch is fixed to the back surface of the middle portion of the leaf spring (for example, configured. , Actual Kaihei 5-5
64).

According to the sensor of this structure, when a predetermined load acts on the outer panel of the vehicle door, the outer panel is deformed and the intermediate portion of the leaf spring is pressed. Therefore, the leaf spring is elastically deformed, and the switch is pressed to conduct electricity.

Here, the sensor having such a configuration is
In order to prevent erroneous operation of the airbag device (erroneous detection of the sensor), a plurality of rows are arranged in a row at a predetermined interval in the vehicle door, and two or more of them are activated (load is detected). The airbag device is configured to be activated.

However, in the sensor of the conventional structure as described above, after the leaf spring is elastically deformed and the switch is pressed to conduct electricity, the leaf spring cannot be further elastically deformed and the switch cannot move. Therefore, only one sensor that detects the load by first pressing the leaf spring will receive the load, and the load will not act on the other adjacent sensor (in other words, two or more sensors will not work). Sensor cannot detect the load), which may make it difficult to properly operate the airbag device.

In this case, even if the leaf spring can be elastically deformed to some extent or the switch can be moved (the stroke of the leaf spring can be secured) even after the switch is pressed and brought into conduction, the sensor In order to reduce the thickness dimension of the plate spring and reduce the thickness of the plate spring, it is necessary to increase the spring constant of the plate spring and set the moving stroke of the plate spring small until the switch becomes conductive. However,
A very large load is required to further elastically deform the leaf spring after the switch is turned on.As a result, only one sensor that detects the load when the leaf spring is pressed first receives the load. Become. On the other hand, it is inevitable that the spring constant of the leaf spring is set low in order to eliminate the above-mentioned inconvenience so that the leaf spring can be largely elastically deformed with a small load even after the switch is turned on. In addition, the moving stroke of the leaf spring until the switch is electrically connected becomes large, and the thickness dimension of the sensor becomes large, so that it is not possible to make the sensor thinner. As described above, securing a large moving stroke of the leaf spring so that only one sensor does not receive the load and reducing the thickness of the sensor are incompatible with each other.

[0008]

SUMMARY OF THE INVENTION In consideration of the above facts, the present invention can reliably detect a load by reliably applying a load to two or more of a plurality of a plurality arranged at a predetermined interval. It is an object of the present invention to obtain a sensor for an occupant protection device that can realize this with a simple and thin structure.

[0009]

According to the present invention, a plurality of a plurality of columns are arranged adjacent to each other at a predetermined distance at positions separated from a body panel by a predetermined distance, and are pressed against the body panel after deformation. A sensor for an occupant protection device that conducts and operates an occupant protection device provided in a vehicle, the pressure receiving portion being elastically deformed by being pressed by the body panel after the deformation, a base portion to which the pressure receiving portion is attached, and the base portion. And a pressure receiving portion, the switch portion being pressed by the elastically deformed pressure receiving portion to conduct the occupant protection device so that the occupant protection device operates, and the pressure receiving portion provided on the base portion so as to project toward the pressure receiving portion. And an elastic characteristic changing protrusion that changes the elastic deformation characteristic of the pressure receiving portion after the switch portion is brought into conduction while keeping the switch portion in the conductive state.

[0010]

According to the occupant protection device sensor having the above structure, when a load of a predetermined value or more is applied to the body panel, the body panel is deformed. Then, the pressure receiving portion is pressed by the deformed body panel, and the pressure receiving portion is elastically deformed. This allows
The switch portion arranged between the pressure receiving portion and the base portion to which the pressure receiving portion is attached is pressed by the pressure receiving portion to be electrically connected.

According to the present invention, after the pressure receiving portion is elastically deformed by the body panel and the switch portion is electrically connected, the elastic characteristic changing protrusion causes the elastic deformation characteristic of the pressure receiving portion to remain in the conductive state of the switch portion. Will be changed in. As a result, the reaction force of the pressure receiving portion decreases (substantially the spring constant decreases), and the pressure receiving portion is further elastically deformed while the switch portion remains in the conductive state. Therefore, among the plurality of sensors arranged at a predetermined interval, only one sensor that detects the load by first pressing the pressure receiving portion does not receive the load, and the load also acts on other adjacent sensors ( In other words, two or more sensors can detect the load properly). Therefore, the occupant protection device provided in the vehicle operates reliably.

As described above, in the occupant protection device sensor according to the present invention, the load is reliably applied to two or more adjacent sensors of the plurality of sensors arranged at a predetermined interval, and the load is detected properly. can do. Even if the spring constant of the pressure receiving part is increased and the moving stroke of the pressure receiving part until the switch part becomes conductive is set small, the substantial spring constant decreases after the switch part becomes conductive, and Since the force is reduced, the pressure receiving portion can be largely elastically deformed with a small load. Therefore, it is possible to secure a large movement stroke of the pressure receiving portion after the conduction while keeping the movement stroke of the pressure receiving portion small until the switch portion is made conductive. It is possible to secure a large movement stroke of the part,
It is possible to solve a problem that was previously a trade-off.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A passenger protection device sensor according to an embodiment of the present invention will be described below with reference to FIGS. Note that FIG.
-In FIG. 6, an arrow FR, which is appropriately shown, indicates the front side of the vehicle,
The arrow UP indicates the vehicle upper side, and the arrow IN indicates the vehicle interior side.

FIG. 4 shows a front door 10 of a vehicle. The front door 10 includes an outer panel 12 as a body panel and an inner panel 14 (see FIGS. 5 and 6). A space 16 inside the door is formed by the outer panel 12 and the inner panel 14.

As shown in FIGS. 5 and 6, a side impact bar 28 and a sensor 30 are provided in the interior space 16 of the door. The side impact bar 28 has an elongated shape, and includes a rectangular flat plate-shaped base portion 28A and a pair of support walls 28B integrally formed at an intermediate portion in the width direction of the base portion 28A. The side impact bar 28 is arranged inside the front door 10 along the vehicle front-rear direction, and both longitudinal ends of the support wall 28B are attached to the shelves 32 provided at both vehicle longitudinal directions of the inner panel 14. . The side impact bar 28 is formed of a high-tensile steel plate, an aluminum alloy, or the like, and when a high load in the direction of arrow A in FIG. 5 acts on the front door 10, the outer panel 12 and the inner panel 14 of the front door 10 will be described.
The deformation amount of is limited.

As shown in FIG. 3, the sensor 30 has an elongated shape and is fixed to a surface of the side impact bar 28 on the outer side of the vehicle compartment by a fixing bracket 70 (see FIG. 6).
The sensor 30 includes a primary sensor 34 for detecting a low load operating state and a secondary sensor 36 for detecting a high load operating state configured by applying the present invention.

The secondary sensor 36 is provided with a rectangular flat plate-shaped base 38 formed of an aluminum alloy plate, and one side surface of this base 38 has a side impact bar 2.
It is in close contact with the outer surface of the vehicle compartment of No. 8. Also, the base 38
On the other side surface (the surface on the outer side of the vehicle compartment), load sensing parts 39 made of aluminum and having low elasticity and low yield strength are arranged at both ends in the width direction thereof. A rectangular flat plate-shaped stay 40 is provided on the surface of the load sensing portion 39 on the outer side of the vehicle compartment.
Is provided. The stay 40 is made of, for example, a steel plate and has high elasticity and high yield strength, and when a predetermined high load acts on the front door 10 from the direction of arrow A in FIG. In case of collision)
Further, the stay 40 is pressed by the deformation of the outer panel 12 and the high load is transmitted to the load sensing portion 39, whereby the load sensing portion 39 is crushed (compressive plastically deforms). A membrane switch 41 is arranged between the base 38 and the stay 40.
In the secondary sensor 36 described above, the load sensing unit 39
By deforming the stay 40 by a predetermined amount while crushing,
The surface of the stay 40 on the side impact bar 28 side presses the membrane switch 41 to turn it on.

On the other hand, the primary sensor 34 as a sensor for an occupant protection device to which the present invention is applied is provided at both longitudinal end portions and longitudinal intermediate portion of the secondary sensor 36, respectively.

As shown in FIGS. 1 and 2, the primary sensor 34 includes a holding bracket 44 as a base. The holding bracket 44 has a support portion 44 that is rectangular in plan view.
A and a pair of leg portions 44B extending in the direction of the side impact bar 28 from both ends of the support portion 44A respectively form a substantially rectangular frame shape as a whole. On the surface of the support portion 44A of the holding bracket 44 on the outer side of the vehicle compartment, a projection 52 as an elastic characteristic changing projection is formed to project.
It can be engaged with a leaf spring 46 described later.

The support portion 44A of the holding bracket 44 is also provided.
A plate spring 46, which has a rectangular shape in plan view and serves as a pressure receiving portion, is disposed on the surface of the vehicle exterior side. The leaf spring 46 has a flat plate-shaped end portion on the side orthogonal to the leg portions 44B of the holding bracket 44, and a shape in which a middle portion is bulged in an arc shape, and the flat plate-shaped one end 46A has a support portion 44A. It is spot welded to the fixed end. Further, the flat plate-shaped other end 46B of the leaf spring 46 is a free end and is in contact with the upper surface of the above-mentioned projection 52, and is held outside the projection 52 when the leaf spring 46 is elastically deformed. Is configured. The elastic force of the leaf spring 46 sets the load to be sensed by the primary sensor 34 to a predetermined value.

An elastic member 62 is attached inside the leaf spring 46 and on the base portion 44A of the holding bracket 44. The elastic member 62 is formed of rubber, urethane, or the like in a block shape, and is elastically deformable in a direction in which the elastic member 62 comes into contact with or separates from the support portion 44A. Further, a membrane switch 48 as a switch portion is arranged on the upper surface (between the leaf spring 46) of the elastic member 62. The membrane switch 48 is arranged in a state of being slightly separated from the leaf spring 46, and when the leaf spring 46 is elastically deformed, the leaf spring 4 is moved.
It is configured to be turned on by being pressed by the intermediate portion 46C of No. 6. From the membrane switch 48, terminals 50 on the plus side and the minus side extend toward the upper side of the vehicle.

In the above-mentioned primary sensor 34, when a predetermined low load acts on the front door 10 from the direction of arrow A in FIG. 5 (for example, when another vehicle collides with the vehicle at a predetermined speed), the outer panel 12 is removed. The intermediate portion 46C of the leaf spring 46 is pressed by this deformation so that the membrane switch 48 is turned on. However, in order to properly operate the airbag device described later, a plurality of primary sensors 34 (2 The airbag operating circuit is configured to close only when it is turned on.

Further, an electric ignition type air bag device as an occupant protection device (not shown) is disposed on the front door 10, and when a plurality of the membrane switches 48 of the primary sensor 34 described above are turned on, or by a secondary device. The membrane switch 41 of the sensor 36 is O
By turning on N, the air bag device operating circuit is closed to operate the air bag device.

Next, the operation of this embodiment will be described. According to the sensor 30 having the above-described configuration, when the sensor 30 is attached to the side impact bar 28, one end 46B of the leaf spring 46 has the holding bracket 4 as shown in FIG. 7 (A).
4 is in contact with the upper surface of the protrusion 52, and the intermediate portion 46C
Is slightly separated from the membrane switch 48.

When a predetermined low load is applied to the front door 10 of the vehicle in the direction of arrow A in FIG. 5, the outer panel 12 of the front door 10 is deformed and the intermediate portion 46C of the leaf spring 46 of the primary sensor 34 is pressed. As a result, as shown in FIG. 7B, the leaf spring 46 is elastically deformed, and the membrane switch 48 is pressed by the intermediate portion 46C to turn on. In addition, the airbag device operating circuit
Only when two or more primary sensors 34 are simultaneously turned on, the circuit is closed and the airbag device is activated.
As a result, a bag body (not shown) of the airbag device bulges from the front door 10.

When a predetermined high load is applied to the front door 10 in the direction of arrow A in FIG. 5, the outer panel 12 of the front door 10 is similarly deformed and the stay 40 of the secondary sensor 36 is pressed. As a result, the load sensing portion 39 is crushed and compressively plastically deformed to cause the secondary sensor 36.
Membrane switch 41 is turned on. Therefore, the air bag device operating circuit is closed and the air bag device operates in the same manner as described above.

Here, in the conventional primary sensor which does not have the protrusion 52 of the holding bracket 44, in order to reduce the thickness of the sensor and make it thinner, the spring constant of the leaf spring 46 is increased to make the membrane switch. It is necessary to set the movement stroke of the leaf spring 46 until 48 becomes conductive to be small. However, as shown by line B in FIG.
After the membrane switch 48 becomes conductive, the leaf spring 46 is further added.
In order to largely elastically deform and secure the moving stroke a, a very large load F ₁ is required, and the overall stroke S ₁ is small, so that thinning can be achieved. Only one sensor, which detects the load by pressing the spring 46, receives the load. On the other hand, if the spring constant of the leaf spring 46 is set to be low in order to solve the above-mentioned problem, as shown by the line C in FIG.
Even after the membrane switch 48 is conducted, the leaf spring 46 can be largely elastically deformed with a small load F ₂ to secure the moving stroke a, but the leaf spring 46 is inevitably kept until the membrane switch 48 is conducted. The movement stroke becomes large, and as a result, the overall stroke S
_{As 2} becomes larger, the thickness of the sensor becomes larger and it is impossible to make it thinner.

As described above, a large movement stroke a of the leaf spring 46 after the membrane switch 48 is conducted so that only one sensor does not receive the load and a thickness of the sensor is reduced. That means
They were antinomy to each other and could not satisfy both.

On the other hand, in the primary sensor 34 of the sensor 30 according to the present embodiment, after the outer panel 12 is deformed, the leaf spring 46 is elastically deformed, and the membrane switch 48 becomes conductive, as shown in FIG. 7 (C). The other flat plate-shaped one end 46B of the leaf spring 46 is held outside of the protrusion 52 by the elastic deformation of the leaf spring 46. Therefore,
The elastic deformation characteristic of the leaf spring 46 is changed while the membrane switch 48 remains conductive. That is, since the length of the beam portion of the leaf spring 46 increases, the substantial spring constant decreases and the reaction force of the leaf spring 46 decreases.

Therefore, as indicated by the line A in FIG. 8, the load does not increase rapidly even after the membrane switch 48 is turned on, and after the membrane switch 48 is turned on, the plate remains in this conducting state. The spring 46 is further elastically deformed, and the movement stroke a of the leaf spring 46 can be secured with a small load F. Therefore, among the plurality of (three in this embodiment) primary sensors 34 arranged at a predetermined interval, only one primary sensor 34, which first detects the load by pressing the leaf spring 46, does not receive the load. , Another adjacent primary sensor 3
The load also acts on 4 (in other words, two or more primary sensors 34 can properly detect the load). Therefore, the airbag device operates reliably.

Further, in the primary sensor 34, after the leaf spring 46 is elastically deformed and the membrane switch 48 is pressed and becomes conductive, the elastic member 62 can bend while the membrane switch 48 remains conductive. Since the elastic member 62 bends as a load acts on the leaf spring 46, the leaf spring 46 can be further elastically deformed even after the membrane switch 48 is turned on. Therefore, the load does not suddenly increase even after the membrane switch 48 is turned on, and even by this, only one primary sensor 34 does not receive the load, and the two or more primary sensors 34 properly load. Can be detected, which is more effective.

As described above, in the primary sensor 34 according to the present embodiment, the load is reliably applied to two or more adjacent primary sensors 34 among the primary sensors 34 arranged at a predetermined interval, and the primary sensor 34 is properly operated. The load can be detected. Further, even if the spring constant of the leaf spring 46 is increased and the movement stroke of the leaf spring 46 until the membrane switch 48 becomes conductive is set to be small, one end 46 of the leaf spring 46 is not made after the membrane switch 48 becomes conductive.
Since B is held apart from the protrusion 52, the substantial spring constant is reduced and the reaction force of the leaf spring 46 is reduced,
The leaf spring 46 can be largely elastically deformed by a small load F. Therefore, the movement stroke a of the leaf spring 46 after conduction can be ensured while keeping the movement stroke of the leaf spring 46 until the membrane switch 48 is conducted, and as a result, the overall stroke S becomes smaller. It is possible to reduce the thickness of the primary sensor 34 to make it thinner, and it is possible to solve a problem that is a trade-off in the past.

In the above-described embodiment, the elastic member 62 is attached to the holding bracket 44 of the primary sensor 34.
The membrane switch 4 is provided on the upper surface of the elastic member 62.
However, the holding bracket 44 is provided with an auxiliary leaf spring similar to the leaf spring 46 at the top portion (between the intermediate portion 46C of the leaf spring 46) of the auxiliary leaf spring. The membrane switch 48 may be provided.

Even in this case, after the leaf spring 46 is elastically deformed and the membrane switch 48 is pressed and becomes conductive, the leaf spring 46 presses the membrane switch 48 and assists while maintaining the conductive state. Since the leaf spring can bend, the leaf spring 46 is further elastically deformed while the auxiliary leaf spring bends as the load acts on the leaf spring 46, and the load abruptly increases after the membrane switch 48 is turned on. There is no. Therefore, the two or more primary sensors can properly detect the load.

In the above embodiment, the leaf spring 46 of the primary sensor 34 has one end 46A fixed to the holding bracket 44. However, the present invention is not limited to this.
Instead of the holding bracket 44, the leaf spring 46 may be directly and integrally fixed to the stay 40 of the secondary sensor 36.

Further, in the above-mentioned embodiment, the primary sensor 34 is provided at three places, but the present invention is not limited to this, and it may be provided at four or more places.

Further, in the above embodiment, the front door 1
Although it is configured to be pressed by the outer panel 12 after being deformed by 0 to press the intermediate portion 46C of the leaf spring 46 of the primary sensor 34, the invention is not limited to this, and the intermediate portion 46C is disposed on the outer peripheral portion of the vehicle and The present invention can be applied to any body panel (for example, an outer panel of a back door of a wagon vehicle or the like) in which a vehicle or the like may collide.

Furthermore, in the above-mentioned embodiment, the airbag device provided on the front door 10 is used as the occupant protection device, and the configuration for operating the airbag device has been described. However, the invention is not limited to this, and other airbags are used. It is applied to devices (for driver's seat, passenger's seat, etc.) and webbing take-up device, which is applied to a so-called pre-load device that rapidly rotates the take-up shaft in the take-up direction using a wire etc. in the event of a vehicle collision, and operates these May be.

[0039]

As described above, in the sensor for an occupant protection device according to the present invention, the load is reliably applied to two or more of the plurality of sensors arranged at a predetermined interval to detect the load properly. It has an excellent effect that it can be realized by a simple and thin structure.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a primary sensor according to an embodiment of the present invention.

2 is a cross-sectional view of the primary sensor of FIG.

FIG. 3 is a perspective view showing a sensor in which the primary sensor of FIG. 1 is used.

4 is a perspective view showing a front door provided with the sensor of FIG. 1. FIG.

5 is a sectional view taken along line 5-5 of FIG.

6 is a sectional view taken along line 6-6 of FIG.

FIG. 7 shows an operating state of the primary sensor of FIG.
(A) is a cross-sectional view showing an initial state, (B) is a cross-sectional view showing a state in which a membrane switch is conductive due to a load, and (C) is a further load after the membrane switch is conductive. It is sectional drawing which shows a state.

FIG. 8 is a diagram showing operating characteristics of the primary sensor of FIG.

FIG. 9 is a diagram showing operating characteristics of a conventional primary sensor.

[Explanation of symbols]

 12 Outer panel (body panel) 34 Primary sensor (sensor for passenger protection device) 44 Holding bracket (base) 46 Leaf spring (pressure receiving part) 48 Membrane switch (switch part) 52 Protrusion (elastic property changing projection)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ho Ho Ho Aichi Noguchi, Oguchi-cho, Niwa-gun, No. 1 Noda, Tokai Rika Electric Co., Ltd. (72) Inventor Takuya Otsuka No. 1, Toyota-cho, Aichi Prefecture Toyota Auto Car Co., Ltd. (72) Inventor Tomoyuki Fukatsu 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd.

Claims (1)

[Claims] 1. An occupant mounted on a vehicle, wherein a plurality of members are arranged adjacent to each other at a predetermined distance from a body panel at a predetermined distance so that the body panel is pressed against the deformed body panel to conduct electricity. A sensor for an occupant protection device that operates a protection device, the pressure receiving portion being elastically deformed by being pressed by the body panel after the deformation, a base portion to which the pressure receiving portion is attached, and arranged between the base portion and the pressure receiving portion. And a switch portion that is pressed by the elastically deformed pressure receiving portion to conduct the occupant protection device and conducts the occupant protection device, and the base portion is provided so as to project toward the pressure receiving portion and engages with the pressure receiving portion. And an elastic characteristic changing projection for changing the elastic deformation characteristic of the pressure receiving portion after the conduction of the switch while the switch portion remains in the conductive state.