JPS6042350Y2 - Shock detection sensor - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an impact detection sensor that emits an electrical signal to activate an external safety device when a vehicle or building receives a dangerous impact. do.

Fig. 1 shows the basic embodiment of the present invention, in which 1 is a high-temperature electrode made by dispersing piezoelectric ceramic powder in rubber or plastic coated around a core wire 1a of a fine metal wire that serves as one electrode. A piezoelectric layer 1b made of a molecular composite piezoelectric material, an aluminum foil tape serving as the other electrode, a thin metal layer such as a mesh of thin metal wires (in this case, a mesh of thin metal wires) 1c1, a protective layer 1d of rubber or plastic provided as necessary 2 is a metal case; The piezoelectric pickup 1 is fitted into a small hole 2a' formed in the bottom surface, here a bottom surface 2a having a large-diameter flange for mounting at a desired location, by means of a thin metal layer 1c at one end 1' of the piezoelectric pickup 1, which is protruded from the small hole 2a'. At the same time, the tip of the protruding portion 1a' of the core wire extending forward from the other end 1'' of the piezoelectric pickup is placed on the other bottom surface of the case 2, the upper end surface 2b in this case, and a small hole 2b' provided in the upper end surface.
It is fixed under tension through the insulating cylinder 3 fitted to the.

Reference numeral 4 denotes a metal weight attached to a protruding portion la' of a core wire extending from the other end 1'' of the piezoelectric pickup and fixed to the upper end surface 2b of the case.

Further, 5a and 5b are a pair connected to the case 2 which is electrically connected to the end of the core wire 1a extending from the piezoelectric pickup 1 downward to the bottom surface 2a of the case and the thin metal layer 1c of the piezoelectric pickup, and connected to an external shock detection circuit. However, by grounding the case 2 side as a negative electrode, the latter lead wire 5b can be omitted.

Next, FIG. 2 shows another embodiment, in which 1 is a piezoelectric pickup, 2 is a metal case, 3 is an insulating tube, and 4 is a metal weight, as in FIG. 1. In this example, the piezoelectric layer is picked up. 1 is implanted on one inner bottom surface of the case 2 through its outermost protective layer 1d, and the protrusion la' of the core wire 1a, which becomes one electrode, is further extended to penetrate the insulating cylinder 3, The end of the metal thin layer 1c, which becomes the other electrode, is connected to the inner bottom surface 2a of the metal case by crossing the lower end surface of the protective layer 1d of the piezoelectric pickup in the outer diameter direction, and this metal thin layer 1c and the metal case It takes some effort to connect the inner bottom surface 2a of the piezoelectric pickup 1 coated with the protective layer 1d.
is advantageous in terms of durability because of its increased elasticity.

In the drawings, the lower end of the core wire 1a of the piezoelectric pickup is shown as being flush with the lower end of the inner bottom surface 2a of the metal case, but the lower end of the core wire 1a is positioned near the upper end surface of the inner bottom surface 2a of the metal case, and It is electrically preferable to provide an insulating space between the two.

As described above, the shock sensor of the present invention has one end of a flexible piezoelectric pickup, which is made of a core wire at the center and whose outer periphery is coated with at least a piezoelectric layer and a thin metal layer, implanted in one inner bottom surface of the case. A weight is attached to the protruding part of the core wire that extends forward from the other end of the piezoelectric pickup and is fixed under tension to the other bottom of the case, and when the case receives a radial impact, the inertia of the weight as a mass is increased. This method is extremely simple because it bends the piezoelectric pickup to induce an electrical signal consisting of a pulse voltage and activates an external shock detection circuit (not shown) connected to the core wire and thin metal layer of the piezoelectric pickup. Despite its structure, mechanical shock from any direction can be extracted as an accurate electrical signal by placing it upright or horizontally at the desired location, and the position of the weight attached to the core wire Also, by selecting the mass, the strength of the safety device that responds to impact can be controlled over a wide range.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing one embodiment of the impact detection sensor of the present invention, and FIG. 2 is a longitudinal sectional view showing another embodiment. 1... Piezoelectric pickup, 1'... One end of the pickup at pressure', 1''... Same other end, 1a... Core wire, la'... ...protrusion,
1b...piezoelectric layer, 1c...metal thin layer,
1d... Insulating protective layer, 2... Case, 2a... One inner bottom surface, 2b... Other bottom surface, 4...... - Weight.

Claims (1)

[Scope of utility model registration request] One end of a flexible piezoelectric pickup having a core wire as the center and the outer periphery of which is coated with at least a piezoelectric layer and a thin metal layer is planted in one inner bottom surface of the case, and extends forward from the other end of the piezoelectric pickup as described above. A weight is attached to the protrusion of the core wire, which is fixed under tension to the other bottom of the case, to bend the piezoelectric pickup and induce an electrical signal when the case receives a radial impact. An impact detection sensor characterized in that the core wire and thin metal layer of the piezoelectric pickup are connected to an impact detection circuit as output terminals.