JPS6229928Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a coin material sorting device that sorts test items by utilizing the transient phenomenon of current flowing through a detection coil.

Conventionally, coin sorting methods include mechanical sorting methods based on weight, outer diameter, or thickness, magnetic sorting methods based on whether or not they are magnetic, and electrical sorting methods in which coins are brought into a magnetic field. Methods that utilize eddy currents generated in coins are well known.

The theoretical basis of the sorting method using eddy currents is described in the paper by F. F. Förster on pages 163 to 171 of the 1952 edition of "Zuaitoschriftführmetalkunde", and the content of this paper is as follows: This is a detection coil method that uses a coil as a magnetic field source, and the impedance value of the detection coil changes individually according to the electrical conductivity value of the coin due to the reaction caused by the eddy current generated in the coin. This method is based on the physical absolute measurement of the electrical conductivity of a coin based on the fact that it exhibits a value of 1. Proposed.

Specifically, as shown in U.S. Pat. An oscillation method is disclosed in which a change in the impedance of a detection coil is converted into a change in the oscillation frequency by incorporating the LC oscillation circuit as L in the LC oscillation circuit. However, in the oscillation method, the deviation of the oscillation frequency due to the material is minute, so it is difficult to implement a filter circuit to detect the deviation, and in the bridge method, it is difficult to set the reference impedance accurately. Deviations due to material are also minute, making it difficult to sort many types of coins with one device.Currently, detection is performed by balancing a specific coin with a reference frequency or reference impedance. Therefore, this system has drawbacks such as the need to switch the reference frequency or reference impedance using a switching device when sorting many types of coins.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide a coin material sorting device that eliminates the above-mentioned drawbacks and is capable of sorting many types of coins with a simple device.

In order to achieve this purpose, the present invention runs a coin in the magnetic field region of the detection coil, and
This detection coil is excited by a step voltage, the time until the voltage due to the excitation current flowing through the detection coil becomes equal to the reference voltage is digitally counted, and coins are sorted based on the counted value. , Examples will be described in detail.

FIG. 1 is a block diagram showing an embodiment of the coin material sorting device according to the present invention.
is an oscillator equipped with a high-frequency crystal oscillator for generating a reference clock pulse; GO is a gate section that allows the clock pulse to pass through in response to a start signal and blocks the clock pulse in response to a coincidence signal, which will be described later; and W counts the clock pulses that have passed through the gate section GO. F is a coin determination unit equipped with a digital comparator that compares the counted value with a preset unique value depending on the material of each coin; When the reference point is reached, a start signal generating device A includes a light emitting diode and a phototransistor for generating the start signal, and A includes a detection coil excited by the start signal. The detection coil excitation device shown in Fig. 2, CO is a comparison unit which compares the voltage generated by the excitation of the detection coil with a preset reference voltage and generates a matching signal as shown in Fig. 2, and Ma is the coin determination unit mentioned above. W
This is a coin storage/ejection mechanism that is activated by an output signal to store or remove coins.

FIG. 2 is a detailed circuit diagram of a part of the block diagram shown in FIG.
is a detection coil that consists of an inductance component L _x and a resistance component R _x and is placed on the coin travel track.
AL, a digital switch SW whose opening/closing operation is controlled depending on the presence or absence of the start signal, and
Comparison voltage proportional to the current flowing through the detection coil AL
It consists of a resistor _R1 for generating Vin. Further, the comparison unit CO includes a comparator C that compares the reference voltage V _ref obtained by the resistors R ₂ and R ₃ with the comparison voltage V _io .

The digital switch SW is one whose opening/closing operation is controlled by logic and other "0" and "1" signals, and as the gate part GO,
A NAND gate G is used.

Next, the operation of the above configuration will be explained with reference to FIGS. 3a to 3d.

First, a coin is inserted, and after running, the detection coil
When reaching the magnetic field region of AL, the light from the light emitting diode (not shown) provided in the magnetic field region by the detection coil AL is blocked, and the phototransistor (not shown) is activated.
The start signal shown in Figure a is sent out. This start signal is applied to the gate section GO and the detection coil exciter A, the gate section GO is opened by this start signal, and the clock pulse sent out from the oscillator O passes through this gate section GO, and the coin judgment section W is opened. The pulse is applied to a counter as a count pulse shown in FIG. 3d, and is counted by the counter.

On the other hand, the detection coil excitation device A generates a step voltage because the digital switch SW is closed by this start signal, and the detection coil is excited.
Therefore, the comparison voltage V _io shown in FIG. 3b is applied to the comparator C.

Note that this comparison voltage V _io exhibits a transient response characteristic shown in equation (1).

On the other hand, the reference voltage V _ref is expressed by equation (2).

V _ref = V _cc / R ₂ + R ₃ · R ₃ ...(2) Therefore, the comparator C compares this comparison voltage V _io and the reference voltage V _ref , and the comparison voltage V _io is equal to the reference voltage V _ref When the two voltages match, the comparator C sends a matching signal shown in FIG. stop.

Also, the inductance component L _x of the detection coil AL
The state of the resistance component _R Since it can be assumed that there is no change in the state of the inductance component L _x and the resistance component R _x of the detection coil AL due to the running of the coin, for all coins, the detection occurs at the moment when the coin blocks the light from the light emitting diode. The status of coil AL can be detected.

On the other hand, the digital switch SW closes only while the traveling coin is operating the photo transistor, and continues to excite the detection coil AL.
The count value unique to the traveling coin given to the coin determining section W is evaluated by a digital comparator (not shown), and an output signal corresponding to the material of the coin is sent to the coin receiving and discharging mechanism M _a . Then, as the coin continues to run and no longer blocks the light from the light emitting diode, the start signal disappears and the digital switch switches on.
In order to open the SW, the comparison voltage V _io begins to decrease excessively, and when it becomes below the reference voltage V _ref , the stop signal disappears, each signal state returns to its initial state, and the next coin can be sorted. .

Furthermore, the device that sorts coins according to their material-specific values mainly uses coins that cannot be sorted by well-known mechanical sorting devices because their size, shape, and weight are similar to those of officially circulating coins. It is used for the purpose of sorting out fraudulent currency and counterfeit currency, and the device of the present invention is extremely suitable for these sorting purposes.

Figure 4 also shows the currently circulating coins, including the 5 yen brass coin (perforated), the 10 yen bronze coin, the 100 yen cupronickel coin, and the stainless steel (SUS) coin with a diameter of 22.0 mm and a thickness of 1.6 mm. , brass (BSP), aluminum (AL), and copper (Cu) discs, the values of the inductance component L _x and resistance component R _x of the detection coil AL are shown in Fig. 5 as a clock pulse.
The number of counts for each material is shown when 2MHz is used, 5V is added as the excitation voltage, and 0.5V is used as the reference voltage.

As explained in detail above, according to the coin material sorting device according to the present invention, the detection coil is excited by a step voltage and the transient phenomenon of the current value flowing through the detection coil is used to determine the time characteristic specific to the coin. numerical value,
In other words, since it detects the difference in L _x /R _x of each material, it is possible to discriminate based on the number of digital counts, and it is possible to sort many types of coins with high precision and instantaneously in a short time. be able to. Furthermore, it is possible to perform processing using a configuration using relatively inexpensive digital elements, resulting in significant effects such as the ability to reduce the cost and size of the device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the coin material sorting device according to the present invention, FIG. 2 is a circuit diagram showing a part of the block diagram shown in FIG. 1 in detail, and FIGS.
d is a diagram showing the waveform of each part in FIG. 2, and FIG. 4 is a diagram showing the inductance component L _x and resistance component R _x of the detection coil when each material having a similar shape acts on the magnetic field region of the detection coil. , FIG. 5 is a diagram showing the count number specific to each material counted by the counter of the coin determining section. O...Oscillator, GO...Gate section, W...Coin determination section, F...Start signal generator, A...Detection coil excitation device, CO...Comparison section, Ma...Coin receiving and discharging mechanism, AL... ...detection coil, SW...digital switch, _R1 to _R3 ...resistance.

Claims (1)

[Scope of utility model registration request] An oscillator that sends out a reference clock pulse, a detection coil that is placed on the trajectory of the coin and is excited by a step voltage when the coin reaches the magnetic field region, and a voltage generated by a transient current flowing through the detection coil. A comparator unit that compares the reference voltage with a reference voltage and sends out a match signal when the two voltages match; and a comparator unit that counts and calculates the reference clock pulses from the time the detection coil is excited until the match output of the comparator unit is sent out. A coin material sorter comprising: a coin determining section that determines the material of a coin based on a numerical value and sends an output signal according to the material of the coin; and a coin receiving and discharging mechanism operated by the output signal of the coin determining section. Device.