JPH04320989A - Magnetic body proximity sensor - Google Patents

Abstract

PURPOSE:To obtain a high sensitivity magnetic body proximity sensor having mechanical electric contacts at low cost. CONSTITUTION:On one end a movable plate 4 supported free of swing like a seesaw, a permanent magnet 7 is fixed, and on the other end, a weight 8 in balance with the permanent magnet 7 is provided. The movable plate 4 is pressed to lean on one side with a week spring 9 and electric contacts 11, 12 which switch on when the movable plate leans on one side, are provided.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic material proximity sensor that detects the proximity of a magnetic material as an electrical signal.

0002

[Prior Art] Magnetic proximity sensors conventionally used in pachinko gaming machines and the like to electrically detect the proximity of pachinko balls are equipped with an oscillation circuit using a high-frequency coil. A common method was to extract changes in the oscillation frequency and disturbances in the oscillation conditions that occur when a ferromagnetic material such as a pachinko ball approaches and output it as an electrical signal.

However, the above oscillation type sensor has the disadvantage that increasing the detection sensitivity requires a very complicated circuit, which increases manufacturing costs, and there are also restrictions on the material of the coil mounting part. there were. For this reason, optical sensors consisting of a light emitter and a receiver have traditionally been used under limited conditions.Although optical sensors have the advantage of being able to extend the detection distance with a relatively simple circuit, There was a problem in that there were restrictions on environmental conditions, such as there must not be anything between the sensors that could block light. Furthermore, the biggest problem with the conventional systems is that in any of the above cases, a signal amplification circuit is required, resulting in high manufacturing costs, and a constant power source is required for its operation, which imposes restrictions on usage conditions.

0004

[Means for Solving the Problems] The magnetic substance proximity sensor of the present invention is intended to solve the above problems, and has a permanent magnet fixed to one end of a movable plate that is swingably supported in a seesaw shape, and another. A weight is provided at the end to balance the weight of the permanent magnet, the movable plate is urged to fall in one direction by a weak spring, and an electric contact is provided that turns on when the movable plate falls in one direction. It is characterized in that it is provided.

[0005]

[Operation] The permanent magnet is attracted to the approaching magnetic body and the movable plate is tilted, so that the electric contact is activated and the approach can be detected as an electric signal.

[0006]

[Embodiment] Next, an embodiment of the invention will be described with reference to the drawings. 1
is a rectangular insulating substrate, and a pair of conductive terminals 2 and 3 are printed on one end of the substrate 1. Reference numeral 4 denotes a movable plate made of a rectangular conductive plate, and the movable plate 4 has fulcrums 5, 5 protruding from both sides of the central portion, and the fulcrums 5, 5 protruding from both sides of the substrate 1. It is pivotally supported by bearing pieces 6, 6, and supports the movable plate 4 so as to be swingable in a seesaw shape. A permanent magnet 7 is fixed to the lower surface of one end of the movable plate 4, and a weight 8 that balances the weight of the permanent magnet 7 is fixed to the other end.

[0007] Reference numeral 9 is a conductive elastic member having one end fixed to the conductive terminal 2 and the L-shaped bent portion 10 at the other end engaged closer to the weight 8 than the fulcrums 5, 5 on the upper surface of the movable plate 4. A spring made of wire rod 9 biases the movable plate 4 so that the permanent magnet 7 side is lifted up. Further, 11 is an electric contact provided on the end of the movable plate 4 on the side of the permanent magnet 7, 12 is an electric contact printed on the substrate 1 so as to face the electric contact 11, and the electric contact 12 and the conductive terminal 3 and is electrically connected to each other through a conductive wire 13 on the substrate 1. 14 is a resin case that is placed over the substrate 1.

An example of the use of this magnetic proximity sensor is shown in FIGS. 3 and 4, in which 15 is a pachinko machine game board, 16 is a ball winning opening provided on the front side of the game board, and 1
7 is a plastic case plate 1 on the back side of the prize opening 16.
This is a winning ball path surrounded by 8. The magnetic substance proximity sensor of the present invention is fixed to the case plate 18 so that the permanent magnet 7 faces the winning ball passage 17, and the winning hole 1
When the pachinko ball 19 that has entered 6 reaches the winning ball path 17, the permanent magnet 7 is magnetically attracted to the pachinko ball 19, tilting the movable plate 4, turning the electric contact 11 on to the electric contact 12, and connecting the conductive terminals 2 and 3. conduction is established.

Although the contacts of this magnetic proximity sensor are opened and closed by mechanical movement, since the permanent magnet 7 and the weight 8 are balanced, it is unlikely to malfunction due to external vibrations. There is little risk of this happening, and there are no restrictions on the mounting position during use. Since it can be operated using the slight attractive force of a permanent magnet, it can detect the approach of magnetic objects with high sensitivity. In addition, regarding chatter, which is a drawback of the mechanical contact method, in the present invention, since the electric contact is closed by magnetic attraction, a hysteresis effect (click action) occurs in the movement, and half-hearted chatter is prevented. Moreover, the magnetic substance proximity sensor of the present invention
Since this is a mechanical contact system, it can be easily used without the need for electronic circuits such as oscillators and amplifiers. Even if this magnetic material proximity sensor is attached to each of the machines, the number of winning pachinko balls in each winning opening can be counted and stored in the computer 19 at low cost, which is effective for grasping the winning rate, etc.

In short, although the present invention is a highly sensitive sensor, it can significantly reduce costs, and when used as a pachinko ball passage sensor for evaluating pachinko machine game boards, detection from a glass surface more than 10 mm away is possible. Detection from outside the ball path is easy, and stable detection is possible because it is completely unaffected by the nails hammered into the game board. In addition, since it is a contact output, it is easy to connect on the measurement side, and although there is a restriction that the object to be detected is only a magnetic material, it has the advantage that there are fewer restrictions on the mounting part and conditions of the sensor, making it easier to handle.

[0011]

As described above, the present invention has the advantageous effect of providing a magnetic proximity sensor that is low in cost and highly sensitive.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of the magnetic material proximity sensor of the present invention.

FIG. 2 is a plan view of the main parts of FIG. 1;

FIG. 3 is a vertical cross-sectional view showing the state of use.

FIG. 4 is a system diagram showing usage conditions.

[Explanation of symbols]

1　　　　　　　　　　　　Substrate 4 Movable plate 7 Permanent magnet 8 Weight 9 Spring 11, 12 Electrical contacts

Claims (1)

[Claims] Claim 1: A permanent magnet is fixed to one end of a movable plate supported swingably in a seesaw shape, and a weight is provided at the other end to balance the weight of the permanent magnet, and the movable plate is supported by a weak spring. A magnetic substance proximity sensor characterized in that the movable plate is biased to fall in one direction and is further provided with an electric contact that turns on when the movable plate falls in one direction.