JP4805479B2 - Normally closed tilt vibration sensor - Google Patents

Description

[0001]
[Technical field to which the present invention pertains]
The present invention relates to a tilt / vibration sensor, in particular, a normally closed type that is incorporated in home appliances, precision machinery and other various industrial machinery and the like so as to detect the tilt or vibration state of those products and devices. The present invention relates to a tilt / vibration sensor.
[0002]
[Prior art]
Conventionally, there are various types of normally closed type tilt / vibration sensors of this type, and one of them is shown in FIG. 3, for example.
That is, as shown in FIG. 3, a pair of left and right container-like electrodes formed by forming an angular concave surface 20 having a substantially trapezoidal cross section inside and forming a gold plating layer 21 on the concave surface by gold plating treatment. 22 and 23 are mounted on a non-conductive case 24 in a manner in which a predetermined interval is provided in the left-right direction and the concave surfaces thereof are opposed to each other, and a surface 25 is gold-plated between the electrodes 22 23 and a gold-plated layer is formed on the surface. 26 is configured to accommodate a conductive ball 27 formed with 26.
In this known normally closed type tilt / vibration sensor or one having a shape / structure similar to this, when the sensor is in the horizontal position, the conductive sphere 27 has both electrodes as shown in FIG. 22 and 23 are in contact with the contact portions 29A and 30A of the inclined surfaces 29 and 30 that expand in the shape of a reverse C on both the left and right sides of the gap 28 between the electrodes, and are electrically connected. When it tilts in either the left or right direction and tilts beyond a predetermined tilt angle, for example, 20 °, the conductive ball 27 rolls on the tilted surfaces 29 and 30 in the tilt direction as shown in FIG. Becomes an open state, and the switch circuit is opened. This type of sensor can fully function as a tilt switch when vibrations do not occur frequently or are not intense.
[0003]
[Problems to be solved by the invention]
However, in this type of sensor, the following problems occur when vibrations occur frequently and severely. That is, in such a case, since the gold plating layer 21 formed on the square concave surface 20 of the electrodes 22 and 23 is a plating layer made of gold, which is a flexible metal, the conductive ball 27 jumps and jumps to the gold plating layer. If the vertical surface or inclined surface of the layer 21 is violently collided or if it jumps up and falls from above and collides with the inclined surfaces 29 and 30, the gold plating layer 21 collided by the impact is uneven as shown in FIG. In addition to the occurrence of 31, a large number of irregularities 32 may occur in the gold plating layer 26 on the conductive sphere 27 side and deform. When the contact portions 39A30A are deformed and deformed in the gold plating layer 21 on the electrodes 22 and 23 side, or when the gold plating layer 26 on the conductive ball 27 side is also uneven at the same time, It has been found that smooth rolling is hindered and contact failure occurs, which has a serious adverse effect on the function as a switch or sensor.
[0004]
The present invention has been made to solve the above-described problems, and is excellent in durability and wear resistance, and sufficiently exhibits not only a function as a tilt switch but also a function as a vibration sensor. The main object of the present invention is to provide a normally closed type tilt / vibration sensor that can perform the above.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the tilt / vibration sensor according to the present invention forms a substantially hemispherical concave surface on the inside and at least a pair of left and right container-like electrodes formed by gold plating the predetermined surface in the left-right direction. The conductive balls are mounted on a non-conductive case in such a manner that the concave surfaces thereof are opposed to each other, and a conductive ball formed by gold-plating the surface between the electrodes is slidably accommodated. Is.
[0006]
The tilt / vibration sensor according to the present invention is characterized in that, in the above, the entire surface of each container-like electrode is gold-plated.
[0007]
Furthermore, in any one of the above tilt / vibration sensors according to the present invention, the concave surface or the entire surface of each container-like electrode and the surface of the conductive sphere are nickel-plated as a pretreatment for gold plating. It is a feature.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
[0009]
FIG. 1 shows a state in which a normally closed type tilt / vibration sensor according to an embodiment of the present invention is in a horizontal position and a pair of electrodes are conducted through a conductive ball, and FIG. 2 shows the sensor to the right. FIG. 4 is a longitudinal front view showing a state in which the conductive sphere is inclined to the right and the electrode is switched off in accordance with the inclination, but hatching of each part is omitted. Also, the terminals for connecting the electrodes to the power source are not shown for the sake of simplicity.
[0010]
1 and 2, reference numerals 1 and 2 denote a pair of left and right formed by forming a substantially hemispherical concave surface 3 on the inner side, and gold-plating the entire surface including the concave surface to form gold plating layers 4 and 5 respectively on the surface. The electrodes 1 and 2 are mounted on a non-conductive case 6 integrally formed of a heat-resistant synthetic resin in a manner in which the electrodes 1 and 2 are spaced apart from each other in the left-right direction and the concave surfaces 3 are opposed to each other. In a substantially spherical void having a radius of about 1.27 to 1.22 cm formed between the electrodes 1 and 2, the surface 7 is gold-plated to form a gold-plated layer 8 on the surface. A ball 9 is housed so as to roll freely. When the sensor is placed in a horizontal position, the conductive ball 9 is brought into contact with the contact portions 3A 'and 3B' of the electrodes 1 and 2 at the bottoms of the electrodes 1 and 2.
[0011]
Each main body portion of the container-like electrodes 1 and 2 is formed by integrally molding a brass block by pressing, and the entire surface thereof is nickel-plated as a pretreatment of the gold-plating process, and the gold-plated layers 4 and 5 Nickel plating layers 4A and 5A are formed below. The gold plating layers 4 and 5 and the nickel plating layers 4A and 5A forming the plating layer of this laminated structure have solid solubility between each other, and the nickel plating layers 4A and 5A reinforce the gold plating layers 4 and 5, respectively. Therefore, it is possible to reduce the cost required for the gold plating process using an expensive gold plating material by thinning the gold plating layer. The conductive ball 9 is made of a material having a large specific gravity, for example, stainless steel, carbon steel, etc. in order to make the contact with the electrodes 1 and 2 good. A nickel plating layer 8 A is formed under the gold plating layer 8. Incidentally, in the illustrated example, the thickness of the nickel plating layers 4A and 5A of the electrodes 1 and 2 is 3 microns, and the thickness of the gold plating layers 4 and 5 is 0.3 microns. On the other hand, the thickness of the nickel plating layer 8 of the conductive sphere 9 is 3 microns, and the thickness of the gold plating layer 8A is 1 micron.
[0012]
In the inclination / vibration sensor configured as described above, the concave surface 3 of each of the electrodes 1 and 2 is substantially hemispherical including the contact portions 3A ′ and 3B ′, and is not angular as in the conventional example. When the sensor tilts from the horizontal position in FIG. 1 to either the left or right direction as shown in FIG. 2 and tilts beyond a predetermined tilt angle, for example, 20 °, the conductive ball 9 tilts on the receiving surfaces 3A and 3B. As a result of smoothly rolling in the direction, the electrodes 1 and 2 are opened, and the switch circuit is opened, so that the inclination of the sensor can be detected. Next, even if the conductive sphere 9 receives vibration and jumps or falls to collide, it immediately rolls along the hemispherical concave surface 3, so the impact due to the collision is extremely weak, and the gold plating on the electrode side and the conductive sphere side is also applied. Since all the layers are reinforced by the nickel plating layer, the contact portions 3A ′, 3B ′ of the concave surface 3 and the conductive spheres contacting the concave portions 3 are not easily deformed. Therefore, it is possible to prevent contact failure in a short time. By the way, when the conventional example and the sensor according to the present invention were repeatedly vibrated to try to compare the durability or wear resistance, the conventional example showed contact failure in about 24 hours. However, in the sensor according to the present invention, it took about 200 hours until the contact failure occurred. In view of this, the latter has a remarkable durability or wear resistance against vibrations that are more than eight times higher than the former. In view of the structure, it will not require many words that the latter is sufficiently useful as a sensor that can detect a vibration state based on a switch on / off operation by vibration.
[0013]
In this way, according to the present invention, it has excellent durability and wear resistance, and can be used not only as a tilt switch but also as a vibration sensor in a wide range of applications. It is possible to obtain a normally closed tilt / vibration sensor that can be used.
[Brief description of the drawings]
FIG. 1 is a longitudinal front view showing a state where a sensor according to an embodiment of the present invention is in a horizontal position and an electrode is conducted through a conductive ball.
FIG. 2 is a longitudinal front view showing a state in which the sensor is tilted to the right and the conductive ball rolls to the right and the electrodes are switched off.
FIG. 3 is a longitudinal front view of a conventional example corresponding to FIG. 1;
FIG. 4 is a longitudinal front view showing a state where a conductive ball is jumped up due to vibration applied from the outside in the conventional example.
5 is an enlarged longitudinal sectional front view of a portion Z in FIG. 4 that shows a slightly exaggerated state of unevenness in the contact portion of the gold plating layer of the electrode and the gold plating layer of the conductive sphere in the conventional example.
[Explanation of symbols]
1, 2 Electrode 3 Hemispherical concave surface 3A, 3B Receiving surface 3A ', 3B' Contact portion 4, 5 Gold-plated layer 4A on electrode side 5B Nickel-plated layer 6 on electrode side Non-conductive case 8 Gold-plated layer 8A on conductive ball side Conductive Nickel plating layer 9 on the sphere side Conductive sphere

Claims (3)

A non-conductive case in which a substantially hemispherical concave surface is formed on the inside, and at least a pair of left and right container-like electrodes formed by gold-plating the concave surface are arranged at predetermined intervals in the left-right direction and the concave surfaces face each other. A normally closed type inclination / vibration sensor, wherein a conductive ball having a surface plated with gold is movably accommodated between the electrodes. 2. The tilt / vibration sensor according to claim 1, wherein the entire surface of each container-like electrode is gold-plated. The tilt / vibration sensor according to claim 1 or 2, wherein the concave surface or the entire surface of each container-like electrode and the surface of the conductive sphere are nickel-plated as a pretreatment for gold plating. Sensor.

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