JP2002365050A - Normally closed gradient vibration sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a normally closed gradient vibration sensor which has a large durability and an ample wear resistance and which can not only perform a function as a gradient switch but also sufficiently perform a function as a vibration sensor. SOLUTION: The normally closed gradient vibration sensor comprises a pair of container-like electrodes 1 and 2 having a substantially semispherical recess 3 formed at an inside and gold-plated on at least the recess 3, installed at a predetermined interval in a lateral direction and mounted at a non- conductive case 6 in a state in which the opposite recess surfaces 3 are opposed, and a conductive sphere 9 gold-plated on its front surface and rotatably contained between the electrodes 1 and 2.

Description

Detailed description of the invention.

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tilt / vibration sensor, and more particularly, to a tilt / vibration sensor incorporated in a home appliance, a precision instrument, and various other industrial machines to detect the tilt or the vibration state of the product / apparatus. The present invention relates to a normally closed type inclination / vibration sensor obtained.

[0002]

2. Description of the Related Art Conventionally, as this type of normally closed type tilt / vibration sensor, there are various structures, one of which is shown in FIG. 3, for example. That is,
As shown in FIG. 3, a pair of left and right container-shaped electrodes 22 formed by forming a square concave surface 20 having a substantially trapezoidal cross section on the inner side and forming a gold plating layer 21 on the concave surface 20 by performing gold plating on the concave surface 20. 23 are disposed at predetermined intervals in the left-right direction, and the concave surfaces thereof face each other.
And a conductive ball 27 formed by gold plating the surface 25 between the electrodes 22 and 23 to form a gold plated layer 26 on the surface is housed. In the known normally closed type inclination / vibration sensor or a sensor having a similar shape / structure, when the sensor is in the horizontal position, the conductive ball 27 is connected to both electrodes as shown in FIG. At the bottoms of 22, 23, the contact surfaces 29A, 30A of the inclined surfaces 29, 30 expanding in an inverted C-shape on both the left and right sides of the gap 28 between the two electrodes are made conductive. When it is tilted in any of the left and right directions and tilts beyond a predetermined tilt angle, for example, 20 °, as shown in FIG.
The conductive sphere 27 rolls on the inclined surfaces 29 and 30 in the inclined direction, so that the electrodes are in an open state, and the switch circuit is opened. This type of sensor can sufficiently exhibit its function as a tilt switch when vibration does not occur frequently or is not severe.

[0003]

However, in the case of this type of sensor, the following problems occur when the vibrations occur frequently and repeatedly or intensely. . That is, in such a case, the electrodes 22, 2
The gold plating layer 21 formed on the square concave surface 20 is a plating layer made of gold, which is a highly flexible metal.
When the conductive ball 27 jumps and collides violently with the vertical surface or the inclined surface of the gold plating layer 21 or jumps up and falls from above and collides with the inclined surfaces 29 and 30, as shown in FIG. Not only are the irregularities 31 generated on the collided gold plating layer 21, but also the gold plating layer 26 on the conductive ball 27 side may be deformed due to a large number of irregularities 32. When the contact portions 39A30A are deformed due to irregularities in the gold plating layer 21 on the electrodes 22 and 23 side, and when the gold plating layers 26 on the conductive ball 27 side are also irregularly formed 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.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has high durability and abrasion resistance.
Further, it is a main object of the present invention to provide a normally closed type tilt / vibration sensor capable of sufficiently exerting not only a function as a tilt switch but also a function as a vibration sensor.

[0005]

In order to achieve the above object, an inclination / vibration sensor according to the present invention has a substantially hemispherical concave surface formed inside and a pair of right and left sides formed by subjecting at least the concave surface to gold plating. The container-like electrodes are mounted on the non-conductive case at predetermined intervals in the left-right direction and the concave surfaces thereof are opposed to each other, and the conductive balls whose surfaces are plated with gold are rollably stored between the electrodes. It is characterized by having a configuration as described above.

Further, the tilt / vibration sensor according to the present invention comprises:
In the above, the entire surface of each container-shaped electrode is gold-plated.

Further, in the tilt / vibration sensor according to the present invention, in any one of the above, the concave surface or the entire surface of each container-like electrode and the surface of the conductive sphere are each subjected to nickel plating as a pretreatment for gold plating. It is characterized by having.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
2 will be described.

FIG. 1 shows a state in which a normally closed type tilt / vibration sensor as one embodiment of the present invention is in a horizontal position, and a pair of electrodes are conductive through a conductive sphere. FIG. It is a vertical front view showing a state in which the conductive sphere is tilted to the right, the conductive sphere is moved to the right and the electrode is switched off, and hatching of each part is omitted. Also, terminals for connecting the electrodes to a power source are not shown in the figure for simplicity.

In FIGS. 1 and 2, 1 and 2 each have a substantially hemispherical concave surface 3 formed therein, and gold plating on the entire surface including the concave surface to form gold plating layers 4 and 5 on the surface. The electrodes 1 and 2 are spaced apart from each other by a predetermined distance in the left-right direction and have a concave surface 3.
Are mounted on a non-conductive case 6 integrally molded of a heat-resistant synthetic resin in a state where the electrodes 1 and 2 are opposed to each other.
A conductive ball 9 having a surface 7 coated with gold and a gold plated layer 8 formed on the surface is rollably housed in a substantially spherical space having a radius of about 1.27 to 1.22 cm formed between the conductive balls 9. Have been. When the sensor is placed in a horizontal position, the conductive sphere 9 is located at the bottom of both electrodes 1 and 2.
The contact portions 3A 'and 3B' are electrically connected to each other.

Each of the main body portions of the container-like electrodes 1 and 2 is formed by integrally forming a brass block by press working, and the entire surface thereof is nickel-plated as a pretreatment for gold plating. 5, nickel plating layers 4A, 5A are formed respectively.
The gold plating layers 4 and 5 and the nickel plating layers 4A and 5A forming the plating layers of the laminated structure have solid solubility between them, 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. Also,
The conductive sphere 9 is made of a material having a large specific gravity, for example, stainless steel, carbon steel, or the like, in order to improve the contact property with the electrodes 1 and 2. Under the gold plating layer 8, a nickel plating layer 8A is formed. Incidentally, in the illustrated example, the thickness of the nickel plating layers 4A and 5A of the electrodes 1 and 2 is 3 μm, and the thickness of the gold plating layers 4 and 5 is 0.3 μm. On the other hand, the thickness of the nickel plating layer 8 of the conductive sphere 9 is 3 μm, and the thickness of the gold plating layer 8A is 1 μm.

In the tilt / vibration sensor configured as described above, the concave surface 3 of each of the electrodes 1 and 2 has contact points 3A ', 3A'
Since the sensor has a substantially hemispherical shape including B ′ and is not angular as in the conventional example, the sensor is inclined from the horizontal position in FIG. 1 in one of the right and left directions as shown in FIG. For example, if the conductive sphere 9 is tilted beyond 20 °, the conductive spheres 9 roll smoothly on the receiving surfaces 3A, 3B in the tilt direction, and the electrodes 1, 2,
As a result, the inclination of the sensor can be detected. Next, even if the conductive sphere 9 receives vibration and jumps or falls and collides, it immediately rolls along the hemispherical concave surface 3, so that the impact due to the collision is extremely weak, and furthermore, gold plating on the electrode side and the conductive sphere side is performed. Since all the layers are reinforced by the nickel plating layer, the contact portions 3A 'and 3B' of the concave surface 3 and the conductive spheres contacting the contact portions 3A 'and 3B' do not easily cause uneven deformation. Therefore, it is possible to prevent the occurrence of a contact failure in a short time. By the way, a comparison was made between durability and abrasion resistance of the conventional example and the sensor according to the present invention by repeatedly applying vibration. As a result, in the conventional example, contact failure was found in about 24 hours. However, in the sensor according to the present invention, about 200
It took time. According to this, the latter is 8 more than the former.
Significant durability or wear resistance to vibrations more than doubled. The latter is switched on by vibration.
It is not necessary to say much in terms of its structure that it is sufficiently useful as a sensor capable of detecting the vibration state based on the OFF operation.

As described above, according to the present invention, a wide range of materials having excellent durability and abrasion resistance and capable of sufficiently exerting not only a function as a tilt switch but also a function as a vibration sensor. It is possible to obtain a normally closed type inclination / vibration sensor which can be used for various applications.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view showing a state in which a sensor according to an embodiment of the present invention is in a horizontal position and electrodes are conductive through conductive balls.

FIG. 2 is a vertical cross-sectional front view showing a state where the sensor is tilted to the right and the conductive sphere rolls to the right with this, and the electrodes are switched off.

FIG. 3 is a longitudinal sectional front view of a conventional example corresponding to FIG.

FIG. 4 is a longitudinal sectional front view showing a state in which a conductive ball is jumping up due to vibration applied from the outside in the conventional example.

FIG. 5 is an enlarged vertical sectional front view of a portion Z in FIG. 4 showing a state in which concavo-convex deformation occurs in a contact portion of a gold plating layer of an electrode and a gold plating layer of a conductive ball in a conventional example.

[Explanation of symbols]

 1, 2 electrode 3 hemispherical concave surface 3A, 3B receiving surface 3A ', 3B' contact part 4, 5 electrode side gold plating layer 4A, 5B electrode side nickel plating layer 6 non-conductive case 8 conductive ball side gold plating layer 8A conductive Nickel plated layer on ball side 9 Conductive ball

Claims (3)

[Claims] 1. A substantially hemispherical concave surface is formed on the inner side, and a pair of left and right container-shaped electrodes formed by plating at least the concave surface are spaced apart by a predetermined distance in the left-right direction, and the concave surfaces are opposed to each other. Attached to the non-conductive case in a manner,
A normally closed tilt / vibration sensor, characterized in that a conductive ball whose surface is gold-plated is rollably accommodated between the electrodes. 2. The tilt / vibration sensor according to claim 1, wherein the entire surface of each of the container-shaped electrodes is gold-plated. 3. The tilt / vibration sensor according to claim 1, wherein the concave or entire surface of each of the container-like electrodes and the surfaces of the conductive spheres are nickel-plated as a pretreatment for gold plating. Tilt / vibration sensor.