JPH05281195A - Material sensor - Google Patents

Abstract

PURPOSE:To obtain a material sensor which improves material detection capacity, at the same time obtains a constantly stable performance, and can be constituted inexpensively. CONSTITUTION:The title sensor is provided with an opening 11 at the central and upper part of a transport path 2 which transports a coin 1 and consists of an air frame part 12 which is provided while surrounding the transport path 2, a first core 13 which is raised and formed from a part corresponding to the lower part of the transport path 2 of the air frame part 12 toward the side of the transport path 2, and second cores 14 and 15 which are raised and formed from both edges of the opening 11 of the air frame part 12 toward the side of the transport path 2. A first coil 16 and a first secondary coil 17 which is electromagnetically induced by the primary coil 16 are wound around the first core 13 and secondary coils 18 and 19 which are electromagnetically induced are wound around the second cores 14 and 15. The material of the coil 1 which is carried on the transport path 2 between the first core 13 and the second cores 14 and 15 is detected according to each output of the secondary coils 17, 18, and 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention discriminates the denomination and authenticity of coins in, for example, a coin processing machine for processing coins, particularly in a coin classifier or coin depositing machine having a forced transfer means for coins. The present invention relates to a material sensor suitable for.

[0002]

2. Description of the Related Art Conventionally, for example, in a coin processing machine for sorting coins by type, coins are dispensed one by one from a hopper that stores coins of mixed denominations to be sorted, and the dispensed coins are dispensed. The coin is conveyed by a forced conveyer such as a conveyer belt, and in the middle of the convey, the denomination, authenticity, etc. of the conveyed coin are discriminated by a discriminating unit including an optical sensor and a material sensor, and the convey is performed based on the discrimination result. The selected coins are sorted and stored in the stacker of the corresponding denomination.

In such a coin processing machine, a magnetic flux transmission type magnetic sensor is used as a material sensor for discriminating the denomination and authenticity of a coin. FIG. 7 shows a schematic structure of a conventional material sensor. The material sensor is wholly molded by resin or the like to be integrated, and the sensor case 51
However, the central part (detection part) 52 for the coin as the object to be detected to pass through and the upper central part 53 are open. A wide first portion is provided under the detection unit 52.
Core 54 is disposed, and a primary coil 55 for excitation and a first secondary coil 56 are wound around the first core 54.
The upper part of the detection part 52 is separated into two parts by the central part 53.
Two second cores 57, 58 are arranged, and the two second cores 57, 58 are arranged.
The cores 57 and 58 of the second secondary coil 59,
60 is wound.

As described above, in the conventional material sensor, the first core 54 below the detecting portion 52 and the second cores 57 and 58 above the detecting portion 52 are magnetically completely opened. FIG. 8 shows how the magnetic flux generated from the primary coil 55 flows in this case. As is clear from this figure, in this state, the loss of the magnetic flux is large, and only a part of the magnetic flux generated by the primary coil 55 is chained to the air gap portion between the first core 54 and the second cores 57 and 58. Don't cross

Therefore, it is necessary to bring the magnetic paths other than the air gap of the detection section (coin transfer section) 52 as close as possible to the closed state, and the first and second cores 54, 57,
A magnetic shield plate 61 made of a magnetic material having high magnetic permeability was attached to the surface of the sensor case 51 in which 58 was housed. Since the magnetic shield plate 61 does not completely close the magnetic path, magnetic shield plates having different shapes are attached to the respective surfaces of the sensor case 51. The magnetic shield plate 61 is thin and is made of a material having a high magnetic permeability, for example, an expensive material such as iron-nickel alloy, and is positioned and fixed to the sensor case 51.

[0006]

As described above, the first
Since the core and the second core are magnetically completely opened, it is necessary to close the magnetic path other than the detection unit (coin transfer unit) as much as possible due to the characteristics, and the surface of the sensor case is thin. A magnetic shield plate was attached. Due to the characteristics, this magnetic shield plate uses an expensive material having a high magnetic permeability, such as an iron-nickel alloy. Further, in order to close the magnetic path as much as possible, the number of the magnetic shield plates is not one, but the magnetic shield plates having the shapes corresponding to the case surfaces are attached to the respective surfaces of the sensor case. That is, a plurality of expensive magnetic shield plates are required. Moreover, the magnetic shield plates need to be positioned and fixed, respectively, which increases the manufacturing process and the number of parts, resulting in an increase in cost.

Further, in the conventional material sensor, since the cores are positioned by the sensor case made of resin, the position between the cores and the air gap cannot be obtained with sufficient accuracy and are varied. There has been a problem that an attempt to make a sensor case satisfying this dimensional accuracy becomes expensive.

[0008] Therefore, an object of the present invention is to provide a material sensor which can improve the material detection ability, can always obtain stable detection performance, and can be constructed at low cost.

[0009]

The material sensor of the present invention comprises:
It has an opening in the upper center of the transport path for transporting the object to be detected,
A core frame portion provided so as to surround the transport path, a first core formed by being bulged toward a side of the transport path from a portion of the core frame portion corresponding to a lower portion of the transport path, and the first core. An excitation primary coil wound around each core, a first secondary coil electromagnetically induced by the primary coil, and a protrusion extending from both ends of the opening of the core frame portion toward the transport path. Two second cores, and a second secondary coil that is respectively wound around the two second cores and electromagnetically induced by the primary coil. Next coil and second 2
The material of the object to be detected passing between the first core and the second core is detected by the output of the next coil.

[0010]

With the above construction, the magnetic flux generated from the primary coil for excitation by the core frame portion forms a closed magnetic path except for the air gap portion between the first core and the second core. The magnetic flux generated in the primary coil is reduced in the air gap so as to interlink the air gap portion. Therefore, the material change in the air gap portion can be accurately detected, and the material detection capability can be improved.

Further, according to the above construction, since an expensive magnetic shield plate as in the prior art is not required, an expensive material is not required, and further, the structure is simple, the number of parts is small, and it can be manufactured at low cost.

Further, with the above configuration, the accuracy of the position (air gap distance, etc.) between the first core and the second core can be improved, so that stable detection performance can always be expected.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 5 shows the construction of a coin material detecting section for detecting the material of coins, which is provided, for example, in the conveying path of a coin processing machine. That is, the coins 1 fed out one by one from the coin feeding portion (not shown) are guided to the conveying path 2, and the central portion of the coins 1 is pressed onto the conveying path 2 by the conveying belt 3 so as to be conveyed in the arrow direction shown in the figure. ing.
A material sensor (magnetic sensor) 4 for detecting the material of the coin 1 to be conveyed is provided in the middle portion of the conveying path 2 in the widthwise center thereof.

FIG. 1 shows the structure of a material sensor 4 according to this embodiment. That is, the core frame portion 12 that has the opening 11 in the upper center of the transport path 2 and is provided so as to surround the transport path 2, and the portion of the core frame portion 12 corresponding to the lower portion of the transport path 2 from the transport path 2 The first core 13 having a wide width is formed to be bulged to the side, and the two second cores 14 and 15 are formed to be bulged from the both ends of the opening 11 of the core frame portion 12 toward the transport path 2 respectively. It consists of

The first core 13 is provided with an exciting coil 1
The secondary coil 16 and the first secondary coil 17 that is electromagnetically induced by the primary coil 16 are wound, and the two second cores 14 and 15 are respectively wound by the primary coil 16. The electromagnetically induced second secondary coils 18 and 19 are wound, and the respective outputs of the first secondary coil 17 and the second secondary coils 18 and 19 cause the first core 13 and The material of the coin 1 conveyed on the conveying path 2 between the two cores 14 and 15 is detected. A sine wave signal having a predetermined frequency is input from the oscillator 20 to the primary coil 16.

Further, the material sensor 4 thus constructed
Is a sensor case 21 that is entirely molded and molded with resin or the like to form a sensor case 21, but a central portion (detection portion) 22 through which the coin 1 conveyed on the conveyance path 2 passes,
The upper central portion 23 corresponding to the opening 11 of the core frame portion 12 is open.

The first secondary coil 17 is assumed to be wound around the primary coil 16. Further, the core portion is formed integrally, for example,
It is composed of a plurality of silicon steel plates laminated.

FIG. 2 shows how the magnetic flux generated by the material sensor 4 constructed as described above flows. FIG. 8 shows how the generated magnetic flux flows in the conventional configuration without the magnetic shield plate. As shown in FIG. 8, the first core 5
In the case where the magnetic path between the fourth core 57 and the second core 57 and 58 is completely open, a part of the magnetic flux generated by the primary coil 55 that is linked to the coin transport portion is large, and the loss is very large. On the other hand, as in the present embodiment of FIG. 2, by completely closing the magnetic paths other than the coin transport unit (detection unit 22), most of the magnetic flux generated by the primary coil 16 is generated in the air gap unit of the coin transport unit. It is possible to accurately detect a change in material of the coin 1 in the coin transporting section, that is, the detecting section 22.

FIG. 6 shows the structure of a processing circuit for processing the output signal of the material sensor 4. In the figure, the output signals of the secondary coils 17, 18 and 19 are amplified by amplifier circuits 31, 32 and 33, respectively. Amplifier circuit 3
The gains of 1, 32, and 33 can be adjusted by variable resistors (not shown). Amplifier circuits 31, 3
The output signals of 2 and 33 are rectified by the rectifier circuits 34 and 3 respectively.
5, 36 and low-pass filter (LPF) 37, 3
Is converted to a DC voltage through 8, 39, and the addition / subtraction circuit 40
Are input respectively. The adder / subtractor circuit 40 is: Vout = amp3 * {amp1 * V21-amp2 *
(V22 + V23)}

The following calculation is performed. Here, V21 is the output of the first secondary coil 17, V22 is the output of the second secondary coil 18, V23 is the output of the second secondary coil 19, amp1 is the amplification factor of the amplifier circuit 31, and amp2 is The amplification factor of the amplification circuit 33, amp3 is the amplification factor of the amplification circuit 33, and Vout is the operation output of the addition / subtraction circuit 40.

The outputs of the low-pass filters 37, 38, 39 and the output of the adder / subtractor circuit 40 are input to an A / D converter 41 and converted into digital signals, and the CPU 4
Sent to 2. The CPU 42 samples the data output from the A / D converter 41 at regular time intervals and stores it in a RAM (random access memory) 4 which is a storage device.
Store in 3. The firmware for operating the CPU 42 is a ROM (Read Only Memory) 44.
Are stored in the memory and are read at regular intervals so that the software operates.

The data read by the CPU 42 as described above is successively compared by the CPU 42, and the maximum value is stored in the RAM.
It is stored in 43. The reference value table for discriminating the coins is stored in advance, for example, in the reference value storage means provided in the ROM 44, and the CPU 42 refers to the reference value table to determine which coin has the maximum value obtained above. The material of the coin is detected by comparing whether it belongs to the level.

The low-pass filters 37, 38, 39
It is assumed that each output of the above is adjusted to a predetermined level in advance, and the output of the adder / subtractor circuit 40 is adjusted to zero in advance.

FIG. 3 shows the output waveform of the material sensor 4 (output of the addition / subtraction circuit 40) for each coin, and FIG. 4 shows the relationship between the output of the material sensor 4 and each coin. In FIG. 4, the upper and lower sides of the square indicate the upper and lower limits of the variation.

With the structure as described above, the magnetic flux generated from the primary coil 16 for excitation by the core frame portion 12 causes an air gap between the first core 13 and the second cores 14 and 15. Since it forms a closed magnetic path except the part,
As the magnetic flux flows as shown in FIG. 2, the magnetic flux generated in the primary coil 16 interlinks the air gap portion with little loss. Therefore, the material change in the air gap portion (detection portion 22) is accurately detected. The material detection ability can be improved.

Further, since an expensive magnetic shield plate as in the prior art is unnecessary, an expensive material is not required, and moreover,
The structure is simple, the number of parts is small, and it can be manufactured at low cost. Furthermore, since the accuracy of the position (air gap distance, etc.) between the first core 13 and the second cores 14 and 15 can be improved, stable detection performance can always be expected.

In the above embodiment, the case of detecting the material of coins has been described, but the present invention is not limited to this. For example, when detecting the material of medals or other metals. Can be similarly applied.

[0029]

As described in detail above, according to the present invention, it is possible to provide a material sensor which can improve the material detection ability, can always obtain stable detection performance, and can be constructed at low cost.

[Brief description of drawings]

1A and 1B show a configuration of a material sensor according to an embodiment of the present invention, FIG. 1A is an external perspective view, and FIG. 1B is a configuration diagram of a core and a coil.

FIG. 2 is a diagram showing a flow of magnetic flux generated by a material sensor.

FIG. 3 is an output waveform diagram of a material sensor for each coin.

FIG. 4 is a diagram showing the relationship between the coins of the output of the material sensor.

5A and 5B show a structure of a coin material detection unit in a coin processing machine, wherein FIG. 5A is a top view and FIG. 5B is a side view.

FIG. 6 is a block diagram showing a configuration of a processing circuit that processes an output signal of a material sensor.

FIG. 7 shows a structure of a conventional material sensor, (a)
The figure is an external perspective view, and (b) is a configuration diagram of a core and a coil.

FIG. 8 is a diagram showing a flow of magnetic flux generated by a conventional material sensor.

[Explanation of symbols]

1 ... Coins, 2 ... Transport path, 3 ... Transport belt, 4 ...
Material sensor, 11 ... Opening part, 12 ... Core frame part, 13 ... First core, 14, 15 ... Second core,
16 ... Primary coil, 17 ... First secondary coil, 1
8, 19 ... Secondary secondary coil, 20 ... Oscillator, 21
…… Sensor case, 22 …… Center part (detection part), 23 ……
… Upper central part.

Claims (1)

[Claims] 1. A core frame portion having an opening at the center upper part of a conveyance path for conveying an object to be detected and provided in a state of surrounding the conveyance path, and a core frame portion corresponding to a lower part of the conveyance path. A first core that is formed so as to bulge from the portion to the conveyance path side, a primary coil for excitation that is respectively wound around the first core, and a first coil that is electromagnetically induced by the primary coil. The secondary coil, the two second cores that are formed so as to bulge from the both ends of the opening of the core frame portion toward the transport path, and the two second cores are wound around the two second cores. A second secondary coil that is electromagnetically induced by a secondary coil, and outputs between the first secondary coil and the second secondary coil between the first core and the second core. Detecting the material of the passing object Material sensor characterized.