JPH06124380A - Coin sensor of coin deciding device - Google Patents

Abstract

PURPOSE:To detect magnetic field variation with high precision by the coin sensor of the coin deciding device which detects the magnetic field vairation due to an eddy current generated in a coil by a receiving coil when the coin moves in a magnetic field produced by a transmitting coil. CONSTITUTION:The transmitting coil 25 is fixed to the inner peripheral wall 21b of a magnetic core 21 in contact with the outer periphery, and a spacer 26 made of a nonmagnetic body is fixed inside the transmitting coil 25 inflush surface with the transmitting coil 25. The receiving coil 30 has a magnetic core 31 in the center and is fixed in a support hole 27 formed in the top surface of the spacer 26 at the same height with the transmitting coil 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coin sensor of a coin discriminating apparatus provided in a device such as a public telephone or a vending machine which is used for coin insertion.

[0002]

2. Description of the Related Art In various types of coin utilization equipment, as shown in FIG. 13, a coin C inserted from a coin slot 1 is rolled and dropped along an inclined coin orbit 10 and is provided along this coin orbit. The material of the coin, depending on the signal from the coin sensor,
A coin discriminating device for discriminating an inserted coin by detecting the thickness and the diameter and discriminating the trueness and type of the coin is provided.

The cross-sectional structure of the coin track 10 of the conventional coin discriminating apparatus is, as shown in FIG. 14 (a), a substrate 15 inclined with respect to the vertical plane, and a constant space from the substrate 15. The flapper 16 and the rail 11 are attached so as to be inclined with respect to the horizontal line of the lower end of the flapper 16. The coin C dropped from the slot to the coin track 10 is inclined with the peripheral end face C contacting the rail 11 and the belly face C ″ contacting the substrate 15.
It rolls down along 1 and passes through a coin sensor S composed of a transmitting coil 12 and a receiving coil 13 mounted so as to face the substrate 15 and the flapper 16, respectively, across the coin orbit. The transmission coil 12 generates an alternating magnetic field in the coin orbit 10, an eddy current is generated in the coin that receives this magnetic field, and the magnetic field due to the eddy current changes the magnetic field of the transmission coil. A signal whose phase and amplitude change in response to the change in the magnetic field is induced in the receiving coil 13.

The coin discriminating apparatus discriminates the type of coin and its trueness by obtaining the material, passage timing, thickness, etc. of the coin from the magnitude and timing of the change of the induced voltage signal of the receiving coil 13, Available coins are distributed to routes according to their type, and unusable coins are sent to the return route.

When the coins are jammed on the coin orbit, or the coin-equipped device cannot be used because the safe is full or the like, the flapper 16 is opened as shown in FIG. It is discharged from 10 and returned via a return route (not shown).

[0006]

However, in the coin sensor having the structure in which the receiving coil 13 moves together with the flapper 16 with respect to the transmitting coil 12 as described above, a slight deviation of the return position of the flapper 16 and vibration of the flapper 16 occur. As a result, the distance between the transmitting coil 12 and the receiving coil 13 changes, and the distance between the receiving coil 13 and the coin also changes. For this reason, even if the same coin is thrown in, a large variation occurs in the induced voltage signal of the receiving coil 13, and the coin cannot be discriminated with high accuracy.

An object of the present invention is to provide a coin sensor for a coin discriminating apparatus which solves this problem.

[0008]

In order to solve the above-mentioned problems, in a coin sensor of the present invention, a coin coil discriminating apparatus is provided with a transmission coil for generating a magnetic field in the coin, and a transmission coil of the transmission coil. In a coin sensor of a coin discriminating apparatus having a receiving coil that detects a magnetic field change due to an eddy current generated in a coin that receives a magnetic field, the transmitting coil is formed in an annular shape, and the opening side of a cylindrical magnetic core whose one surface is closed. The receiving coil is fixed concentrically inside the magnetic core so that the outer peripheral portion is in contact with the inner peripheral wall, and the receiving coil is fixed inside the transmitting coil in the same direction and substantially flush with the non-magnetic body. Has been done.

[0009]

As described above, in the coin sensor of the present invention, the annular transmission coil is fixed along the inner peripheral wall of the cylindrical magnetic core on the opening side, and the reception coil is substantially flush with the inside of the transmission coil in the same direction. Since the non-magnetic material is fixed at the position where the magnetic flux is integrated, the magnetic flux generated from the opening side end surface of the magnetic core is concentrated near the opening surface due to the excitation of the transmitter coil. A strong magnetic field is applied to the coin moving along the coin orbit, the relative position of the receiving coil and the transmitting coil does not change, and both coils are almost flush, so this coin sensor is If fixed so as to be flush with the inner wall of the substrate, the gap between both coils will be constant at the shortest distance, and changes in the magnetic field can be detected stably and with high sensitivity.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show an example coin sensor 20.

The coin sensor 20 has a cylindrical magnetic core 21 having a closed bottom and a high magnetic permeability, and small-diameter lead holes 22 and 23 penetrate through the bottom 21a. A ring-shaped transmission coil 25 is adhered and fixed to the inner peripheral wall 21b of the magnetic core 21 so that the outer periphery thereof is in contact. The lead wires L1 and L2 of the transmission coil 25 are drawn out from the lead hole 22 of the bottom portion 21a of the magnetic core 21.
The height of the transmitter coil 25 is equal to the inner peripheral wall 21b of the magnetic core 21.
The upper surface 22a of the transmitter coil 22 and the upper end surface 21c of the magnetic core 21 are flush with each other.

Inside the transmission coil 25, a columnar spacer 26 made of a non-magnetic material (such as plastic) is adhesively fixed. The outer circumference of the spacer 26 is in contact with the inner circumference of the transmission coil 25, and the height of the spacer 26 is the same as that of the transmission coil 25.
At the center of a, a cylindrical support hole 27 is formed with a predetermined depth.

Between the bottom of the support hole 27 and the bottom surface of the spacer 26, a small-diameter lead hole 28 continuous with the lead hole 23 of the magnetic core 21 penetrates. Inside the support hole 27,
The receiving coil 30 is bonded and fixed in the same direction as the transmitting coil 25. Lead wires L3, L4 of the receiving coil 30
Are drawn out through the lead holes 28 of the spacer 26 and the lead holes 23 of the magnetic core 21.

At the center of the receiving coil 30, a magnetic core 31 having a high magnetic susceptibility is attached. The outer circumference of the receiving coil 30 is in contact with the inner circumference of the support hole 27, and the heights of the receiving coil 30 and the magnetic core 31 match the depth of the support hole 27.

Therefore, the receiving coil 30 is fixed to the transmitting coil 25 and the magnetic core 21 in a concentric and flush position with the spacer 26.

FIG. 4 shows a magnetic field distribution when the transmitter coil 25 of the coin sensor 20 is excited at a predetermined frequency (for example, 40 KHz), and the magnetic force lines from the upper end surface 21c of the magnetic core 21 outside the transmitter coil 25 are shown. But the receiving coil 3
It is confirmed that a high density is generated in the vicinity of 0, and as a result of an experiment, a magnetic force having a density several times higher than that of the state without the magnetic core 21 is applied to coins close to the transmission coil 25 and the reception coil 30. Was done.

Also, in an experimental comparison with a coin sensor in which a magnetic substance is present in the gap between the transmitting coil 25 and the receiving coil 30, this coin sensor 20 has a magnetic flux density almost twice that of the receiving coil 30 (magnetic field). It was confirmed that it was 2.4 times higher (when the core 31 was not provided) than when the magnetic core 31 was provided.

FIG. 5 is a view showing a state in which the coin sensor 20 is attached to the substrate 15 'of the coin orbit 10. The coin sensor 20 is inserted in the circular sensor hole 18. The coil surface of the coin sensor 20 is fixed inside the sensor hole 18 so as to be substantially flush with the inner wall surface 15a 'of the substrate 15'.

As shown in FIG. 6, the transmission coil 25 is excited and driven at a predetermined frequency by an AC signal from the oscillator 40 ((a) of FIG. 7) to generate an alternating magnetic field on the coin orbit 10 and the reception coil. The AC signal induced in 30 ((b) of FIG. 7) is output to the sample hold circuit 42 via the buffer amplifier 41.

The sampling pulse generating circuit 43 receives the AC signal of the oscillator 40 and generates a sampling pulse ((c) in FIG. 7) whose phase is delayed by 180 degrees with respect to the induction signal of the receiving coil 30 when there is no coin. To do.

Therefore, from the sample-hold circuit 42, when there is no coin, when the coin passes, when the phase and amplitude of the induced signal of the receiving coil 30 change due to the magnetic field generated by the eddy current, the phase and amplitude change. A detection signal ((d) in FIG. 7) corresponding to the above is held and output.

The waveform and peak position of this detection signal depend on the excitation frequency, the diameter, material and thickness of the coin. For example, as shown in FIG. 8A, when a small-sized coin C1 and a large-sized coin C2 made of the same material at the same excitation frequency are compared, the waveform of the detection signal due to the passage of the small-sized coin C1 shows that the eddy current Since only the outer circumference of the large-sized coin passes through the receiving coil 30, the single-peaked shape has a narrow width as shown by A in FIG. Since the outer peripheral portion having a large current and the central portion having a small eddy current pass through the portion of the receiving coil 30, the width is bimodal and wide as shown in B. Further, if the material and the thickness are different, the magnitude of the eddy current also changes, and the peak value of the waveform also changes.

The coin discriminating circuit 45 discriminates any or all of the specific information (material, diameter, thickness) of the coin from the detected waveform and the detected waveform of another coin sensor (not shown) and the like to determine the type and trueness of the coin. Determine false.

Upon receipt of this determination result, the coin sorting circuit 46 drives a sorting mechanism (not shown) to send the coin to a path corresponding to the determination result.

In addition, if the coin is jammed on the coin orbit 10,
Flapper 1 if the device cannot be used with coins
6'opens as shown in FIG. 9 (a), and the coin C is discharged to a return route (not shown). After this discharge, even if the flapper 16 'does not completely return as shown in FIG. 9B,
Since the transmission coil 25 and the reception coil 30 are integrated and the distance between the coin sensor 20 and the coin C does not change, the discrimination of coins is not affected. Further, as shown in FIG. 4, the coin sensor 20 has a magnetic flux that leaks toward the outer periphery in the magnetic core 2.
Since it is suppressed to a very small value by 1, there is no adverse effect even if other magnetic sensors are placed in the vicinity,
Since the shape of the coin sensor 20 itself is also small, the coin trajectory can be shortened and the size of the entire coin discriminating apparatus can be reduced.

In this embodiment, the transmitting coil 25 and the receiving coil 30 are fixed inside the cylindrical magnetic core 21, but like the coin sensor 20 'shown in FIG. Transmitter coil 25 'and spacer 2 in core 21'
6 ', the receiving coil 30' may be fixed, or the position of the receiving coil may be fixed at a position deviated from the center of the transmitting coil, and the fixing method of each coil is not limited to the above-described embodiment, and various methods may be used. Deformation is possible.

Further, as shown in FIG. 11, the magnetic core 21
The magnetic core 50 having substantially the same shape as the above may be fixed so as to face the flapper 16 '. Such a magnetic core 5
When 0 is used, compared with the case where only the coin sensor 20 is used,
Although the magnitude of the signal induced in the receiving coil 30 'hardly changes, a stronger magnetic field can be applied to the outer peripheral side of the coin and the entire coin sensor is magnetically closed except for the coin orbital portion. However, there is an advantage that stable detection can be performed without being affected by the magnetism from the outside, moreover, no magnetic adverse effect is given to the outside, and another magnetic sensor can be arranged in proximity.

In the above embodiment, the plastic spacer 26 for supporting the receiving coil is used as the non-magnetic material between the transmitting coil and the receiving coil. You may make it a space | gap part (air is made into a nonmagnetic material) and support a receiving coil with a small supporting member.

Further, as in the coin sensor 60 shown in FIG. 12, a plurality of coils (4 in FIG. 13) are provided inside one transmitting coil 25.
The individual receiving coils 30 may be arranged in a line. In this case, if the coin sensor 60 is attached in such a direction that each receiving coil 30 has a different height position with respect to the trajectory, it is possible to select a receiving coil according to the size of the coin and perform coin discrimination.

[0030]

As described above, in the coin sensor of the coin discriminating apparatus of the present invention, the annular transmitting coil is attached along the inner peripheral wall of the cylindrical magnetic core whose one surface is closed, and the receiving coil is attached to the transmitting coil. Since the non-magnetic material is sandwiched inside and fixed in the same direction and flush so as to form an integrated structure, the relative position of the transmitter coil and receiver coil does not change, and there is a positional shift due to the opening and closing of the flapper. However, stable detection can be performed. Further, since it can be mounted flush with the inner wall of the coin orbit, it is possible to give a strong magnetic field to the coin that is generated by the excitation drive of the transmission coil so as to concentrate in the vicinity of the opening surface from the end surface on the opening side of the magnetic core, Stable and highly sensitive detection of coins is possible.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an embodiment of the present invention.

FIG. 2 is a plan view of an example.

FIG. 3 is a sectional view taken along line AA of the embodiment.

FIG. 4 is a magnetic field distribution diagram of an example.

FIG. 5 is a cross-sectional view of a coin track showing a state in which a coin sensor of one embodiment is attached.

FIG. 6 is a block diagram showing a circuit configuration of a coin discriminating apparatus using the coin sensor of the embodiment.

FIG. 7 is a signal diagram of each part of the circuit of FIG.

FIG. 8 is a diagram showing an example of the difference in the detected waveform depending on the size of the coin diameter.

FIG. 9 is a diagram showing an opening / closing operation of a flapper.

FIG. 10 is a perspective view showing another embodiment of the present invention.

FIG. 11 is a sectional view showing another embodiment of the present invention.

FIG. 12 is a layout view of a transmission coil and a reception coil according to another embodiment of the present invention.

FIG. 13 is a schematic diagram of a coin trajectory of a coin discriminating apparatus.

FIG. 14 is a cross-sectional view of a coin track on which a conventional coin sensor is attached.

[Explanation of symbols]

 10 coin track 11 rail 15 'substrate 16' flapper 20 coin sensor 21 magnetic core 25 transmission coil 26 spacer 27 support hole 30 receiving coil 31 magnetic core

Claims (1)

[Claims] 1. A coin discriminator, which is arranged beside a coin orbit,
In a coin sensor of a coin discriminating apparatus having a transmission coil that generates a magnetic field in the coin and a reception coil that detects a magnetic field change due to an eddy current generated in the coin that receives the magnetic field of the transmission coil, the transmission coil is formed in an annular shape. And is concentrically fixed inside the magnetic core so that the outer peripheral portion is in contact with the opening-side inner peripheral wall of the cylindrical magnetic core whose one surface is closed, and the receiving coil is a non-magnetic material inside the transmitting coil. A coin sensor for a coin discriminating apparatus, wherein the coin sensor is fixed in a position that is in the same direction as the transmission coil and is substantially flush with the transmission coil.