JPH0650776Y2 - Acceleration detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an acceleration detector using a mercury switch mounted to control a moving body such as an automobile.

[Prior Art] As a method for detecting acceleration, an acceleration detector main body 21 using a mercury switch 20 as shown in FIG. 4 has been generally used conventionally. Reference numeral 1 is a case of a conventional acceleration detector body having a rectangular parallelepiped shape and having a bottomed concave portion 1a. Reference numeral 2 is a mercury switch body having a hollow hollow cylindrical shape and both ends thereof having a hemispherical shape and having a sealed inside. At one end 2a of the mercury switch body 2, wire rod-shaped terminals 2b, 2c inserted into the mercury switch body 2 with a proper length are insulated from each other and extend in a protruding manner. Terminal protruding from the mercury switch body 2
The ends of 2b and 2c are connected to the harness 22 in the recess 1a of the case 1. The harness 22 penetrates the case 1 from the inner surface 1b of the recess 1a of the case 1 and is guided to the outside of the case 1 to form the connector 23.
Connected to. The connector 23 is connected to a terminal (not shown) of the control circuit.

The mercury switch body 2 contains a mercury ball 2d in such an amount that it comes into contact with the above-mentioned two inserted terminals 2b and 2c. A mercury switch 20 is formed by the above-described mercury switch body 2, the terminals 2b and 2c, and the mercury ball 2d. In such a mercury switch 20, the end 2e of the mercury switch body 2 is attached to the case 1
In the vicinity of the inner surface 1b of the concave portion 1a of the
2a is located near the opening of the recess 1a of the case 1 and is provided with an appropriate inclination in the vertical direction. Thereafter, the recess 1a of the case 1 is filled with the mold resin 4 so as to fix the mercury switch 20 and a part of the harness 22. The acceleration detector main body 21 formed as described above is attached to a screw 24 penetrating the mounting portion 1d of the case 1 in a state where the bottom surface 1c of the case 1 of the acceleration detector main body 21 is in contact with an appropriate place such as an automobile. Fixed.

In the acceleration detector main body 21 installed as described above, when acceleration is not acting on the acceleration detector main body 21, the mercury ball 2d in the mercury switch 20 is on the end 2a side of the mercury switch main body 2 and Two terminals 2b, 2c extending inside the body 2
Is in contact with. Therefore, the terminals 2b and 2c are in a conductive state via the mercury bulb 2d, and the mercury switch 20 is in an on state. Fourth
When acceleration is applied in the direction of arrow B in the figure, the mercury ball 2d moves from the end 2a side of the switch body 2 toward the end 2e against the inclination, but the mercury ball 2d contacts both terminals 2b, 2c. During this time, the mercury switch 20 is in the on state. When the acceleration is further applied in the B direction, the mercury ball 2d moves further to the end 2c side, and comes out of contact with the terminals 2b, 2c. Therefore, the terminals 2b and 2c are brought out of conduction, and the mercury switch 20 is turned off. When the acceleration acting on the acceleration detector main body 21 decreases, the mercury ball 2d moves toward the end 2a by gravity and contacts the terminals 2b and 2c again, so that the mercury switch 20 is turned on.

By detecting the on / off state of the mercury switch in this way, the acceleration detector detects whether or not an acceleration of a certain level or more acts.

[Problems to be Solved by the Invention] However, in the conventional acceleration detector body as described above, the mercury switch has a high reliability and the failure rate is low, while the mercury switch and the control provided outside the acceleration detector body. There has been a problem that the failure rate of the harness and the connector section for connecting to the circuit is high.

The present invention has been made to solve the above-described problems, and by not using a harness and a connector that connect the acceleration detector body and the control circuit, the acceleration detector has a low failure rate and a reduced cost. Intended to provide the body.

[Means for Solving the Problems] The present invention is an acceleration detector that is provided in a moving body and is affected by vibration caused by movement of the moving body. The acceleration detector includes a plurality of mercury switches for detecting acceleration of the moving body, and the mercury. An electric circuit board for electrically and mechanically connecting terminals extending from the switch, and an acceleration detector main body covering the mercury switch and the terminal on the electric circuit board. One of the two extending terminals is connected to each other inside the acceleration detector main body.

[Operation] The mercury switch provided in the acceleration detector main body detects an acceleration of a certain level or more and changes the output electric signal. Since the terminal extending from the mercury switch main body from which the electric signal is output is directly connected to the electric circuit on the electric circuit board, there is no moving part of the conductive wire and the reliability is high.

[Embodiment] First Embodiment In FIG. 1, reference numeral 1 is a case of an acceleration detector main body of the present invention, which is a three-dimensional shape and has a bottomed recessed portion 1a, and 2 and 3 are hollow cylinders. The mercury switch body has a shape and both ends are hemispherical and the inside is sealed.
Wire-shaped terminals 2b, 2c and 3b, 3c inserted into the mercury switch bodies 2 and 3 with appropriate lengths project and extend from the one ends 2a and 3a of the mercury switch bodies 2 and 3, respectively. In addition, terminal 2b
And 2c are electrically isolated. The same applies to terminals 3b and 3c. The portions of the terminals 2b, 2c and 3b, 3c inserted into the mercury switch bodies 2 and 3 are in an airtight state. Further, the mercury switch bodies 2 and 3 include mercury balls 2d and 3d in such an amount that they come into contact with the above-mentioned two inserted terminals. Mercury switch bodies 2 and 3 as described above
So that one ends 2a and 3a thereof are located near the opening side in the recess 1a of the case 1 and the other ends 2e and 3e of the mercury switch bodies 2 and 3 are located on the bottom surface 1b side of the recess 1a. It is provided in the concave portion 1a of the case 1 having a proper inclination in the vertical direction. The mercury switch bodies 2 and 3 have the same inclination, but the inclination directions are opposite to each other by 180 °. The recess 1a of the case 1 provided with the mercury switch bodies 2 and 3 is filled with a non-conductive mold resin 4 and the mercury switch bodies 2 and 3 and the terminals 2b, 2c and 3b, 3c are fixed. .

The acceleration detector main body 6 is configured by the above-described components 1, 2, 3, and 4. The acceleration detector body 6 is installed by contacting the upper surface of the electric circuit board 7 with the surface 1c of the case 1.
The case 1 of the acceleration detector main body 6 and the electric circuit board 7 are fixed by screws 8 from the opposite surface 7a on which the acceleration detector main body 6 is installed. The terminals 2b, 2c and 3b, 3c extending from the mercury switches 2 and 3 penetrate the electric circuit board 7 and are soldered to the surface 7a of the electric circuit board 7 to be electrically connected.

The acceleration detector main body 6 as described above is installed at an appropriate place of a moving body such as an automobile in a form in which the acceleration detector main body 6 is provided on the electric circuit board 7 as shown in FIG. When no acceleration acts on the acceleration detector body 6, the mercury balls 2d and 3d in the mercury switch bodies 2 and 3 are
Terminals 2b, 2c and 3b, 3c located on the ends 2a and 3a inside the mercury switch body and extending inside the mercury switch bodies 2 and 3.
Is in contact with. Therefore, the terminals 2b, 2c and 3b, 3c are electrically connected through the mercury balls 2d and 3d, and the mercury composed of the mercury switch bodies 2 and 3 and the terminals 2b, 2c and 3b, 3c. The switch is in the on state.

For example, when acceleration acts on the acceleration detector body 6 in the direction A shown in FIG.
To the end 2e side of the mercury switch body 2
Move against the inclination of. However, the mercury ball 2d is connected to the terminals 2b, 2
While touching both c, the mercury switch is on.

When the acceleration is further applied in the A direction, the mercury ball 2d moves further to the end 2e side and comes out of contact with the terminals 2b and 2c extending inside the mercury switch body 2. Therefore terminal 2b
There is no continuity between and 2c, and the mercury switch is turned off.

When the acceleration becomes small or stops working, the mercury ball 2d moves toward the end 2a side of the mercury switch body 2 by gravity, so that the mercury ball 2d again contacts the terminals 2b and 2c and the mercury switch is turned off. It returns to the ON state again.

When acceleration acts in the B direction shown in FIG. 1,
With respect to the mercury switch body 3, the same action as in the case of the mercury switch body 2 described above works.

As described above, in the acceleration detector according to the first embodiment, the switch is activated when a positive or negative acceleration of a certain level or more acts on the acceleration detector body.

Second Embodiment This embodiment has the same structure as the acceleration detector main body shown in the first embodiment, but changes the method of fixing the acceleration detector main body and the electric circuit board. . In Fig. 2, the same components as those in Fig. 1 are designated by the same reference numerals. Reference numeral 1 is a case of the acceleration detector body, 2 and 3 are mercury switch bodies, and 2b, 2c and 3b and 3c are wire rod-shaped terminals extending from the mercury switch bodies 2 and 3. The terminals 2c and 3b extending from the mercury switch bodies 2 and 3 are close to each other in the recess 1a of the case 1 and are connected by the contact 10. Further, the terminals 2b and 3c are cut in the recess 1a of the case 1 and connected to the wire-shaped second terminals 11 and 12 having higher mechanical strength than the terminals 2b and 3c by the contacts 11a and 12a, respectively. Molded resin 4 is filled in the concave portion 1a of the case having the above-described structure, and the mercury switch bodies 2 and 3 and the terminal are fixed. The above-mentioned second terminal 11
And 12 extend from the surface 1c of the case 1 with an appropriate length. Such an acceleration detector main body 6 is installed so that the second terminals 11 and 12 penetrate the electric circuit board 7 and the surface 1c of the case 1 is in contact with the upper surface of the electric circuit board 7. Further, the second terminals 11 and 12 are soldered to the back surface 7a of the electric circuit board 7, and the acceleration detector body 6 and the electric circuit board 7 are fixed and electrically connected.

The operation of the acceleration detector main body in the second embodiment as described above is the same as that of the first embodiment. That is, when no acceleration is applied to the acceleration detector body 6, the mercury balls 2d and 3d in the mercury switch bodies 2 and 3 come into contact with the terminals 2b, 2c and 3b, 3c in the mercury switch bodies 2 and 3, respectively. Therefore, the second terminals 11 and 12 are in a conductive state, and the mercury switch is in an on state. When an acceleration exceeding a certain level acts on the acceleration detector main body 6, the mercury ball 2d or 3d of either the mercury switch main body 2 or 3 is connected to the terminals 2b, 2c or 3
Since they are not in contact with b and 3c, the second terminals 11 and 12 are in a non-conducting state, and one of the mercury switches is in an off state. When the acceleration stops, the mercury ball 2d or 3d contacts the terminals 2b, 2c or 3b, 3c, and the mercury switch returns to the ON state.

As described above, since the acceleration detector main body according to the second embodiment is fixed to the electric circuit board by the terminal having high mechanical strength, the acceleration detection is performed on the electric circuit board as shown in the first embodiment. Screws or the like for fixing the body of the acceleration sensor are not required, and the acceleration sensor body can be easily connected to the electric circuit board.

Third Embodiment In this embodiment, a plurality of mercury switches are configured inside the acceleration detector main body so that the magnitude of acceleration acting on the acceleration detector main body can be discriminated. In FIG. 3, the same components as those in FIG. 1 are designated by the same reference numerals. Reference numeral 1 is a case of the acceleration detector main body, and 15, 16 and 17 are, for example, the above-mentioned mercury switch main body 2, terminals 2b and 2c, and a mercury ball 2d.
It is the same mercury switch that was formed in. Among them, the mercury switches 15, 16 and 17 have the same inclination in the concave portion 1a of the case 1, but the inclination angles are different from each other, that is, the inclination angle of the mercury switch 15 is the smallest and the inclination angles are large in sequence. Therefore, the tilt angle of the mercury switch 17 is the largest. Thus, the recess 1a of the case 1 provided with the mercury switches 15, 16 and 17 is filled with the mold resin 4 to form the acceleration detector main body 6. The acceleration detector body 6 is fixed on the electric circuit board 7 by the method shown in the first embodiment.

The acceleration detector body as described above operates in the same manner as in the first and second embodiments described above, but since it has three mercury switches with different tilt angles, it has three levels. Acceleration can be detected. That is, when no acceleration acts on the acceleration detector body 6, the mercury switches 15, 16 and 17 are all in the ON state. When a certain acceleration or more in the B direction shown in FIG. 3 is applied, the mercury switch 15 is turned off, but the mercury switches 16 and 17 are turned on. When acceleration is further applied, the mercury switches 15 and 16 are turned off,
The mercury switch 17 is turned on. When acceleration is further applied, all mercury switches 15, 16 and 17 are turned off. If the acceleration continues to decrease from the acceleration at which all of the mercury switches 15, 16 and 17 are turned off, the mercury switches 17, 16 and 15 are turned on in this order from the off state. Return to.

As described above, in this embodiment, three levels of acceleration can be detected.

As is clear from the above-described first to third embodiments, since the output terminal of the mercury switch for detecting acceleration is directly connected to the electric circuit board, the lead wire of the electric signal output from the mercury switch has a force from the outside. It will not be twisted or pulled by. Therefore, the failure rate in the conductor portion is drastically reduced as in the conventional example, and the reliability of the acceleration detector body is improved. Furthermore, since parts such as a harness and a connector are not required, the product cost is reduced. Further, since the acceleration detector main body is provided on the electric circuit board, the space can be saved more than the conventional example.

[Advantage of the Invention] As described in detail above, according to the present invention, the acceleration detector body is installed on the electric circuit board, and the terminal extending from the mercury switch body protruding from the acceleration detector body is directly connected to the electric circuit board. The electric signal output from the mercury switch is directly output to the circuit on the electric circuit board by being attached to. Therefore, the electric signal conducting wire for signal transmission, which has a high probability of failure in the related art, can be eliminated, and a highly reliable acceleration detector with further reduced cost can be provided. In addition, by connecting each one of the two terminals extending from each of the mercury switches to each other inside the acceleration detector main body, the number of connection points between the electric circuit board and the terminals is reduced, and the reliability is further improved. Can be improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an acceleration detector body showing a first embodiment of the present invention, FIG. 2 is a vertical sectional view of an acceleration detector body showing a second embodiment of the present invention, and FIG. FIG. 4 is a vertical sectional view of an acceleration detector main body showing a third embodiment of the present invention, and FIG. 4 is a vertical sectional view showing a conventional acceleration detector main body. 1 ... Case, 2, 3 ... Mercury switch main body, 7 ... Electric circuit board.

Claims (2)

[Scope of utility model registration request] 1. An acceleration detector provided on a moving body and affected by vibration caused by movement of the moving body, comprising: a plurality of mercury switches for detecting acceleration of the moving body; and a terminal extending from the mercury switch. An electric circuit board electrically and mechanically connected, and an acceleration detector main body covering the mercury switch and the terminal on the electric circuit board. Two pieces each extending from each of the plurality of mercury switches. One of each of the terminals is connected to each other inside the acceleration detector body. 2. The terminal extending from the mercury switch in the acceleration detector body is electrically and mechanically connected to the electric circuit board via a second terminal.
The described acceleration detector.