JPH0374438B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a coin inspection device used in a coin sorting device such as a vending machine or a money changer.

Conventional technology Conventionally, coin inspection devices using an oscillating coil and a receiving coil are disclosed in, for example, Japanese Patent Publication No. 57-35510, Japanese Patent Publication No. 57-35511, Japanese Patent Publication No. 55-17998,
It is already known in Japanese Patent Publication No. 54-26200, Japanese Patent Publication No. 55-15756, Japanese Patent Publication No. 57-557, Japanese Utility Model Publication No. 17257-1984, etc. However, in these conventional techniques, even if it is possible to detect differences in the material and diameter of the coin, it is very difficult to detect the difference in the uneven pattern between the center of the coin and its periphery. Figures 2-a and 2-b show an example of such a conventionally known coin detection device. Two receiving coils 2b and 2c are arranged facing each other between the coin passages formed between the side plates P1 and P2, and the center point of the oscillating coil 2a is placed at a position where the center of the coin to be inspected passes, and
The center line of the oscillating coil 2a was arranged to coincide with the midpoint between the two receiving coils 2b and 2c. Further, Fig. 2-b shows the coin inspection device 3 for detecting the diameter of coins, in which an oscillating coil 3a and two receiving coils 3b, 3c are installed on both sides of the coin passage 1.
are placed facing each other, and the two receiving coils 3
The center point of the oscillation coil 3a was made to coincide with the midpoint between the coils 3c and 3c, and was placed at a position through which the periphery of the coin to be inspected passed. And Figure 2-a, Figure 2-
Coin inspection devices 2 and 3 shown in figure b are arranged upstream and downstream of the coin passage 1, and a low frequency of about 25KHz is applied to the oscillation coil 2a of the coin inspection device 2 for inspecting the material, and a coin inspection device for diameter inspection is applied to the oscillation coil 2a of the coin inspection device 2 for inspecting the material A high frequency of about 100 KHz is applied to the oscillating coil 3a of the inspection device 3, and when the coin passes, each of the receiving coils 2b, 2c,
The authenticity and type of coins were determined by inspecting and determining the material and diameter of the coins based on the peak values of the voltage waveforms obtained from 3b and 3c. However, when sorting two or more coins that have almost the same diameter and are made of almost the same material, and the only difference is the uneven pattern on the coin surface or the presence or absence of holes, this is especially true when the coins are thick and When the distance between the oscillating coils 2a, 3a and the receiving coils 2b, 2c, 3b, 3c becomes large, it becomes very difficult to use the above conventional method, and the voltage waveforms obtained from the receiving coils 2b, 2c, 3b, 3c are almost the same. I couldn't sort it out. For example, as shown in FIG. 5, the magnetic flux from the oscillating coil 2a is diffused and the receiving coil 2a
This is because the amount reaching b and 2c decreases, and the output level of the receiving coil decreases, making it impossible to detect the uneven pattern on the surface of the coin or subtle differences in the presence or absence of holes. Therefore, as a method for detecting and sorting out the uneven patterns and holes on the surface of coins, two coils connected in series with opposite phases are used as the receiving coil, and the midpoint between the oscillating coil and the receiving coil is A method was developed by the applicant for a patent to select the presence or absence of uneven patterns and holes by arranging them in a staggered manner (see Japanese Patent Publication No. 63-57835).

Problems to be Solved by the Invention The present invention improves the above-mentioned drawbacks of the prior art, and solves the problem of the uneven pattern and holes even for two or more coins in which the only difference is the uneven pattern on the surface of the coin or the presence or absence of holes. This system allows coins to be sorted based on their presence or absence, and this problem is solved by means different from the invention described in Japanese Patent Publication No. 63-57835.

Means for Solving the Problems An oscillation coil whose winding axis direction is parallel to the coin passage surface is disposed on one side of the coin passage,
On the other side, a receiving coil is disposed, the winding axis of which is perpendicular to the coin passage surface, and the receiving coil is composed of two coils connected in reverse phase in series, and the intermediate point between the two receiving coils is connected to the oscillating coil. The midpoints of the two are arranged so that they almost coincide.

Effect When a low frequency is applied to the above oscillation coil and a coin is caused to flow down the coin path, voltage waveforms with different peak voltages are generated in the above two receiving coils depending on the coin's material, uneven pattern, and presence or absence of holes. From this voltage waveform, it is possible to determine the type of coin and whether it is genuine or false.

Embodiment FIG. 1 is a sectional view showing an embodiment of the present invention.
is a coin passage, and the coin passage 1 is formed by side plates P1, P2 and bottom plate P3, and these side plates P1,
P2 and the bottom plate P3 are formed of a non-magnetic material, and the coin passage 1 is inclined so that coins fall down the coin passage according to the inclined bottom plate P3 (in Fig. 1, the bottom plate The coin falls while rolling on P3). Reference numeral 4a denotes an oscillation coil arranged on one side of the inclined coin passage 1, and the winding axis direction of the coil is arranged parallel to the surface of the coin passage 1, and the oscillation coil 4a They are arranged so that their midpoints almost coincide. 4b and 4c are receiving coils disposed on the other side of the coin passage 1, and the winding axes of the receiving coils 4b and 4c are arranged perpendicular to the surface of the coin passage 1, and The midpoint between 4b and 4c and the midpoint of the oscillation coil 4a are arranged to substantially coincide with each other. The receiving coils 4b and 4c are substantially the same coils connected in series with opposite phases. In this embodiment, coins are selected based on the coin's material and surface pattern, and the center of the falling coin is made to match the midpoint of the oscillation coil 4a. If coins are to be sorted based on their differences, the oscillation coil 4a may be placed around the falling coins.

The oscillating coil 4a and the receiving coil 4 as described above
As shown in FIG. 3, the oscillating coil 4a is connected to an oscillator, and the receiving coils 4b, 4c are connected to a discrimination circuit 7 via an amplifier circuit 6, as in the conventional example. The discrimination circuit 7 detects the voltage level of the waveform detected by the receiving coils 4b and 4c and discriminates the test coil as in the conventional example.

When the oscillator 5 oscillates at a frequency of about 25KHz and the oscillating coil 4a is excited, the receiving coils 4b and 4c
A current is generated by the magnetic flux generated by the oscillating coil 4a, but the direction of the magnetic flux passing through the receiving coils 4b and 4c is opposite, and the direction of the magnetic flux passing through the receiving coils 4b and 4c is opposite.
c is connected in reverse phase, so the receiving coils 4b,
The output from 4c is normally at a constant level. However, when a coin that has fallen down the coin path 1 passes through the coin inspection device, the above-mentioned constant level state is broken, and the voltage generated at the output ends of the receiving coils 4b and 4c is amplified by the amplifier circuit 6, and the coin is discriminated. It is input to the circuit 7, but the receiving coils 4b, 4
The measured voltage generated at the output terminal of c varies depending on the magnetic permeability, shape, and pattern of the material of the passing coin, and this is determined by the discrimination circuit 7.
to distinguish between genuine coins, counterfeit coins, and types of coins. Compared to conventional coin testing devices of this type, the coin testing device of the present invention not only measures voltage levels that vary depending on the material of the coin, but also has larger coin thickness and a larger distance between the oscillating coil and the receiving coil. It has become easier to detect uneven patterns on the coin surface and differences in the presence or absence of holes, which were difficult to detect with conventional coin inspection devices. This is because, as shown in Fig. 4, the amount of magnetic flux output from the oscillating coil 4a reaches the receiving coils 4b and 4c increases, and the detection level on the receiving side increases, resulting in a large change in the detected voltage. It is possible to distinguish between the uneven patterns on the surface of Nari coins and the presence or absence of holes. In particular, compared to the invention described in Japanese Patent Publication No. 63-57835, which detects uneven patterns on the surface of coins and differences in the presence or absence of holes, the difference in detection output is larger, allowing more accurate sorting.

Figures 6-a and 6-b are diagrams showing the experimental results of the present invention and the conventional example, and the coins used in the experiment were a 50 yen coin and a 25 centimos coin (Philippines cupronickel coin without a hole).

The 50 yen coin and the 25 centimos coin have the following characteristics.

50 yen coin External size: 21.0 mm (with hole) Thickness: 1.75 mm Material: Cupronickel 25 centimos coin External size: 21.0 mm (without hole) Thickness: 1.75 mm Material: Cupronickel As mentioned above, 50 yen coins and 25 centimos coins have holes. They have very similar shape characteristics depending on whether they exist or not.

The arrangement of the oscillating coil and the receiving coil was as shown in FIG. 2-a in the conventional example, and an experiment was conducted and compared with the arrangement of the present invention shown in FIG. In this case, the center position of the oscillating coil is placed 10.5 mm from the bottom of the coin passage, and two receiving coils are placed on the opposite side of the coin passage at positions 3.5 mm apart in opposite directions from the center line of the oscillating coil. The two receiver coils were placed so that their center lines were aligned. That is, the second
The difference between the conventional arrangement shown in FIG. 1 and the arrangement of the present invention shown in FIG. 1 is that the direction of the oscillation coil is changed by 90 degrees. The experiment was conducted under the same operating conditions as follows.

Oscillation frequency: 25KHz Oscillation coil: 1000μH Receiving coil: 1000μH x 2 Oscillation level: 15Vp-p Coil external shape: Diameter 6.2mm, length 3.6mm Coil material: Ferrite In the conventional example, two receiving coils are connected in series in normal phase. , the present invention connects in series with opposite phases.

As described above, by using the same oscillating coil and receiving coil, under the same electrical conditions, and simply changing the direction of the oscillating coil and the connection of the receiving coil, you can exchange 50 yen coins and 25 yen coins.
Figures 6-a and 6-b show the results of an experiment using centimos coins.

Figure 6-a shows the case of the conventional example shown in Figure 2-a, where the detected output waveforms are almost the same for both the 50 yen coin and the 25 centimos coin, and no difference can be detected.

On the other hand, FIG. 6-b is a diagram showing the detection output waveform when the present invention is implemented, and shows that there is a clear difference in the detection output waveform, and that two coins can be distinguished.

As described above, the present invention shows that it is possible to easily detect two coins that differ by the presence or absence of holes, which could not be detected conventionally, and to identify the two coins.

Effects of the Invention In the conventional oscillating coil and receiving coil for inspecting the material of coins, the winding axis direction of the oscillating coil is parallel to the coin passage surface, and the winding axis direction of the two receiving coils is parallel to the coin passage surface. By arranging the receiving coil vertically so that the midpoint between the two coils and the midpoint of the oscillating coil almost match, the amount of magnetic flux output from the oscillating coil crossing the receiving coil is increased, and the detection level is increased. Since we have made the coins higher, not only coins made of different materials, but also
With the same outer diameter, it is possible to distinguish between uneven patterns on the surface of coins and the presence or absence of holes, and with a simple configuration, it is possible to easily distinguish between the coins, which was previously impossible. be.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the arrangement of an oscillating coil and a receiving coil of a coin inspection device according to an embodiment of the present invention, Fig. 2-a
2-b is a diagram showing a conventional coin inspection device for inspecting material and outer diameter, FIG. 3 is a block diagram of an embodiment of the present invention, and FIG. 4 is an embodiment of the present invention. Figure 5 is a diagram explaining the magnetic flux distribution of the conventional example, Figure 6-a, Figure 6-b
The figure is a diagram showing detected output waveforms of a conventional example and an embodiment of the present invention. 1... Coin passage, 4a... Oscillation coil, 4b,
4c... Receiving coil, P1, P2... Side plate, P3
……Bottom plate.

Claims (1)

[Claims] 1. In a coin inspection device comprising an oscillating coil on one side of a coin passage and a receiving coil facing the oscillating coil on the other side, the oscillating coil has a winding axis direction parallel to the coin passage surface. The receiving coil is arranged in parallel, and the receiving coil is composed of two coils connected in series and in reverse phase, with the winding axis direction of the coil perpendicular to the coin passage surface, and the middle point of the two coils and the middle point of the oscillating coil. A coin inspection device characterized by having dots arranged almost in agreement.