JPH0612539Y2 - Sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a so-called G sensor, and in particular, from the outside according to the rolling amount of a rolling element that rolls against the biasing force of a wound strip. The present invention relates to a sensor that detects the magnitude of impact.

[Prior art]

As this kind of sensor, there is a G sensor 21 shown in FIGS. 3 to 4. That is, this is used by being incorporated in a so-called airbag provided in a car seat. The sensor 21 has a cylindrical mass 23 rotatably mounted on a flat surface portion 22 of a base. A steel belt 24, one end of which is fixed, is wound around the mass 23 and is urged in the fixing direction. Steel belt 2
Gold foil 25 is attached at an appropriate position in the winding direction of No. 4.
This gold foil 25 is a steel belt 2 due to rolling of the mass 23.
Due to the unwinding of No. 4 due to the unwinding, it comes into contact with the contact 26 provided so as to project from the flat surface portion 22. Reference numerals 27 and 28 denote fixed-side stoppers and rolling-side stoppers, which are located on both sides of the mass 23 in the rolling direction and are respectively provided at both ends of the plane portion 22.

The sensor 21 is arranged in the circuit of the airbag system. The airbag system includes a squib that is a heater, an explosive provided around the squib, and an airbag provided around the explosive.

When an impact G is applied from the direction of the arrow in the figure, that is, from the rolling stopper 28 side, the mass 23 resists the biasing force of the steel belt 24 and moves from the fixed stopper 27 side to the rolling stopper 28 side. Roll around. With the rolling of the mass 23, the steel belt 24 is unwound and extends, and the extension causes the gold foil 25 to come into contact with the contact 26 and short-circuit.
When the contact 26 is short-circuited, the circuit of the airbag system is closed, the squib is energized to ignite the explosive, and the airbag inflates due to the explosion of the explosive.

[Problems to be solved by the device]

By the way, when the impact G is applied, the mass 27
When the steel belt 24 is extended by rolling of the steel belt 24, the gold foil 25 provided on the steel belt 24 comes into contact with the contacts 26 to operate the airbag system. However, it is not possible to determine that an impact equal to or less than the impact G, that is, a weak impact G of about 0.5 to 1.5 G applied during normal traveling is applied.

Therefore, whether the mass 27 is defective, the contact 26 is defective, or the circuit is defective, whether the device is in a normally operable state or not until the airbag system is activated. There was a problem that it could not be confirmed.

The present invention has been made in view of the above circumstances to solve the problem, and an object of the present invention is to provide a sensor capable of confirming the state of the device in advance.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention places a rolling element on a flat surface and winds an elastic strip that urges in one direction around the peripheral surface of the rolling element. The sensor for detecting the magnitude of impact by rolling against the urging force of the body is provided with means capable of detecting a plurality of rolling amounts without contact in the rolling direction of the rolling body.

[Action]

According to the configuration of the present invention, when an impact is applied from the outside, the rolling element rolls against the biasing force of the elastic strip that is wound around the peripheral surface and biases in one direction. Depending on the rolling amount, a plurality of rolling amounts are detected without contact, and the magnitude of impact is detected.

〔Example〕

 The present invention will be described based on an embodiment shown in the drawings.

FIG. 1 is a front view and FIG. 2 is a side view.

A rolling element that constitutes the G sensor 1, for example, a columnar mass 2 is rotatably mounted on a flat surface portion 3 of a base. One end side of this mass 3 is fixed and attached to the fixed side. A biasing elastic strip, for example, a steel belt 4 is wound. A disk 5 having a plurality of slits 5a in the circumferential direction is provided on the end side of the mass 3 so as to rotate integrally. Further, a sensor 6 is provided in the rolling direction of the mass 2 with the upper and lower surfaces of the disk 5 sandwiched therebetween, and can detect the presence or absence of passage of the slit 5a without contact by a plurality of photointerrupters or MR sensors. . This sensor 6 outputs a plurality of detection signals according to the rolling amount of the mass 3, and when the slit 5a passes through the position of the sensor 6 which is the farthest from the fixed portion of the steel belt 4 ( (State of two-dot chain line in FIG. 1), that is, 0.5 to 1.5 added during normal running
The air bag system is not energized until a large impact G of G or more, for example, an impact of about 2.5 G is applied. Reference numerals 7 and 8 are a fixed side stopper and a rolling side stopper, respectively.

The operation of the above arrangement when arranged in the circuit of the vehicle airbag system will be described. Now, when an impact G is applied from the outside, the mass 2 rolls on the flat surface portion 3 against the urging force of the steel belt 4, but the slit 5a of the disc 5
A plurality of detection outputs are output to the outside in a non-contact manner every time the sensor passes the position of each sensor 6. Then, the sensor 6 at the position farthest from the fixed position of the steel belt 4 is slit 5
When “a” passes, that is, when a shock larger than the shock applied during normal running is applied, the detected output energizes the air bag system to drive the air bag system, but the previous output causes a shock during normal running. Depending on, you can check whether the device is in a state where it can operate normally.

Moreover, the detection output is detected without contact, and the reliability can be improved as compared with the case of detecting with contact.

In addition, in the above-described embodiment, the case where the detection output is obtained without contact has been shown, but both contact and contact may be provided.

[Effect of device]

As is apparent from the above description, according to the present invention, it is possible to detect a plurality of masses according to the rolling amount of the mass, and it is possible to detect a plurality of impacts having different sizes.
Since it is possible to constantly monitor whether or not the device is in a state in which it can normally operate and to detect it without contact, it is possible to improve the reliability of the device.

[Brief description of drawings]

The drawings show one embodiment of the sensor according to the present invention. Fig. 1 is a front view, Fig. 2 is a side view, Figs. 3 and 4 are conventional examples, and Fig. 3 is a plan view and Fig. 4. Is a side view. (Explanation of reference numerals in drawings showing main parts) 1 ... G sensor, 2 ... mass 3 ... flat surface portion, 4 ... steel belt 5 ... disk, 5a ... slit 6 ... sensor

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A rolling element is placed on a flat surface, and an elastic strip for urging in one direction is wound around a peripheral surface of the rolling element, and the rolling element resists the urging force of the strip due to an external impact. In the sensor for detecting the magnitude of impact by rolling, a sensor is provided which is capable of detecting a plurality of rolling amounts without contact in the rolling direction of the rolling element.