JPH10143703A - Metal discriminating sensor and coin discriminator using the sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal discriminating sensor which has its stable characteristic to the dimensional variance of a core by using a case which forms a detection surface, a coil which is fixed to the case and the core which pierces through the coil. SOLUTION: This sensor consists of a case 1 which forms a detection surface 1a, a coil 3 which is fixed to the case 1, and an E-shaped core 2 which is fitted to the case 1 to pierce through the coil 3. Then the sensor is attached to a side wall 10 which forms a path 9 of a detection object 8 and has its stable characteristic since the distance 7 has no change between the surface 1a and the coil 3 despite the change of thickness 6 of the core 2. Furthermore, the coil 3 can be produced in a mass and at a low cost by an automatic winding machine when an air core coil is used as the core 3. The coil 3 is also can be produced in a mass by the automatic winding machine when the coil 3 is used as a sensor that is wound round a bobbin. Both case 1 and bobbin can use the resin as their materials and accordingly high adhesive intensity is secured between the coil 3 and the case 1 owing to those resin materials.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal identification sensor for electrically identifying the material and shape of a metal such as a coin, and a coin identification device using the same.

[0002]

2. Description of the Related Art In recent years, vending machines have become widespread, and high identification performance is required for metal identification sensors for identifying coins and the like used therein.

Conventionally, this type of metal identification sensor has a structure as shown in FIG. That is, it has a case 1 constituting the detection surface 1a, a core 2 fixed to the case 1, and a coil 3 fixed to the core 2 so that the core 2 penetrates. FIG. 7 shows an example in which the case 1 and the core 2 and the core 2 and the coil 3 are fixed with the adhesives 4 and 5.

[0004]

However, in such a conventional configuration, when the depth dimension 6 of the core 2 fluctuates,
Accordingly, the coil 3 fixed to the core 2 with the adhesive 5 moves, and as a result, the distance 7 between the detection surface 1a and the coil 3 varies. Therefore, there is a problem that the characteristics of the sensor change due to the fluctuation of the distance 7.

The variation of the depth dimension 6 of the core 2 is based on the following reasons. That is, ferrite having good magnetic properties is generally used for the core, and the ferrite is produced by pressing a powder and then sintering the powder. 10 for sintering
Dimensional accuracy is low because shrinkage occurs by as much as 20%. When high precision is required, costly grinding is required.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a metal identification sensor having stable characteristics with respect to dimensional fluctuation of a core.

[0007]

In order to achieve this object, a metal identification sensor according to the present invention comprises a case forming a detection surface, a coil fixed to the case, and a coil penetrating the coil. And a core.

Thus, a metal identification sensor having stable characteristics can be obtained.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a metal having a case constituting a detection surface, a coil fixed to the case, and a core provided through the coil. This is an identification sensor. Even if the core depth changes due to shrinkage due to heat sintering or the like, the distance between the detection surface and the coil does not change, so that stable characteristics can be obtained.

According to a second aspect of the present invention, there is provided the metal identification sensor according to the first aspect, wherein the coil is an air-core coil, and the coil can be manufactured in large quantities at low cost by an automatic winding machine.

According to a third aspect of the present invention, there is provided the metal identification sensor according to the first aspect, wherein the coil is wound around a bobbin, and the coil can be mass-produced by an automatic winding machine. Further, both the case and the bobbin can be made of a resin, and the coil and the case are fixed to each other, so that a high adhesive strength can be obtained.

According to a fourth aspect of the present invention, there is provided the metal identification sensor according to the first aspect, wherein the coil is directly wound around the case. Since the operation of fixing the coil and the case is unnecessary, the cost of the fixing operation is reduced. Can be reduced.

According to a fifth aspect of the present invention, there is provided the metal identification sensor according to the first aspect of the present invention, wherein the path of the detection object is constituted by a case, and the distance between the sensor and the detection object is reduced by using the case and the path together. In addition, the sensitivity of the sensor can be increased.

According to a sixth aspect of the present invention, there is provided the metal identification sensor according to the first aspect, wherein a connection terminal is provided on a case, wherein a starting end and an end of a coil are wound around a conductive connection terminal by an automatic machine. The printed circuit board can be automatically dip-soldered for sensor wiring, and the efficiency of assembly can be increased.

According to a seventh aspect of the present invention, there is provided a detection object passage, a first coil fixed to one side surface of the passage, a first core provided through the coil, A metal identification sensor having a second coil fixed to the other side of the passage so as to face the first coil, and a second core provided through the coil. And the second coil, the outputs of the first coil and the second coil can be added by a method such as connecting these two coils in series. Can be measured from both sides. Further, the output of each coil is affected by the position of the detected object in the passage and causes a decrease in measurement accuracy. However, when measurement is performed from both sides, this effect is canceled out, and high measurement accuracy is obtained.

According to an eighth aspect of the present invention, there is provided the metal identification sensor according to the seventh aspect, wherein the passage is constituted by the first side wall and the second side wall, and the side surface of the passage can be separated. , Repairs, etc. are facilitated.

According to a ninth aspect of the present invention, there is provided the metal identification sensor according to the seventh aspect, further comprising means for opening and closing the side wall. Can be opened and closed.

According to a tenth aspect of the present invention, a coin insertion slot, a coin passage connected to the coin insertion slot, a coin identification sensor disposed on a side wall of the coin passage, and an output of the coin identification sensor. Detecting means for detecting the characteristics of the inserted coin, a storage circuit for storing in advance data serving as a reference for authenticity and type of the coin, and a comparison for comparing the output of the detecting means with reference data of the storage circuit A coin discriminating apparatus comprising: a circuit; and a judging circuit for judging the authenticity and type of a coin based on a comparison result of the comparing circuit, wherein the coin discriminating sensor uses the metal discriminating sensor according to claim 1. Even if the depth dimension of the core changes, the distance between the detection surface and the coil does not change, so that the sensor has stable characteristics and can achieve high coin discrimination performance.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is a sectional view of a metal identification sensor according to Embodiment 1 of the present invention. In FIG. 1, a metal identification sensor according to the present embodiment includes a case 1 constituting a detection surface 1a, a coil 3 fixed to the case 1, and an E-type provided on the case 1 through the coil 3. Side wall 1, which comprises a core 2 having a shape,
It is attached to 0. In this embodiment, an example in which the case 1 and the coil 3, the case 1 and the core 2, and the case 1 and the side wall 10 are fixed with the adhesives 11, 12, and 13 is fixed. Other methods are also possible.

With the above configuration, even if the depth dimension 6 of the core varies, the distance 7 between the sensing surface 1a and the coil 3 is reduced.
Has stable characteristics because it does not change. Experiments were conducted with four types of cores having different depth dimensions from 3.2 mm to 5.2 mm and a coil having a width of 2 mm. As a result, when the coil is fixed to the bottom of the core as in the conventional configuration,
Inductance change due to difference in core depth dimension is 5
In contrast to 0%, when the coil is fixed to the case as in the present embodiment, the change in inductance is 1%.
Met.

As described above, according to the present embodiment, stable sensor characteristics can be obtained with respect to dimensional variations of the core. This eliminates the need for a grinding step, which requires a high manufacturing cost, and can reduce the cost of the sensor.

(Embodiment 2) FIG. 2A is a plan view showing the vicinity of a metal identification sensor according to Embodiment 2 of the present invention, and FIG. 2B is a sectional view taken along the line AA of FIG. 2A. It is. In FIG. 2, the metal identification sensor according to the present embodiment includes a case 14, which forms a detection surface 14 a and also serves as a side wall forming a passage 9 of the detection object 8, and a coil 3 fixed to the case 14. An E-shaped core 2 provided in a case 14 through the coil 3 and two mounting portions 14b of the case 14 (one is denoted by reference numeral 14b and the other is not shown,
(Same below).

The mounting portion 14b is provided with the core 2 of the case 14.
It is formed in a cylindrical shape on the same side as the mounting of, and a mounting hole is provided in the center of the top of the cylinder,
On the side surface of the cylinder, the start end 3a or the end 3 of the coil 3
A guide portion 14c for guiding b is provided. The case 14 has a winding shaft 14d serving as a shaft when the coil 3 is wound.
And a thread path portion 14 for pulling out the starting end 3a of the coil 3.
e is formed. The start and end portions 3a and 3b of the coil 3 are wound around the two connection terminals 15 and 16, respectively, and the connection terminals 15 and 16 are connected to a printed board 17 for sensor wiring by solders 18 and 19, respectively. ing.

The assembling method of the metal identification sensor having the above-described configuration will be described below. First, the connection terminals 15 and 16 are press-fitted into the mounting portion 14b of the case 14. The connection terminals 15 and 16 were made of inexpensive mild steel wire with good solderability, and were formed in a prismatic shape. This is because the end of the coil 3 wound around the connection terminals 15 and 16 can be easily cut or shaped by adopting the prismatic shape.

Next, in order to fix the winding itself, the coil 3 uses a polyurethane fusion-bonded copper wire, and melts the fusion coating with methyl alcohol, and then performs the winding. The winding is first wound around the connection terminal 15 and then the case 14
And then wound around the winding shaft 14d. Then, after being guided to a guide portion (not shown), the terminal end portion 3b is wound around the connection terminal 16, and finally the winding is cut.

The guide portion 14c is provided below the lower surface of the coil 3 (the one closer to the detection surface 14a). This is to ensure that the starting end 3a of the coil 3 escapes from the moving range of the nozzle 20 that supplies the winding (the portion above the lower surface of the coil 3). Further, since the winding state of the coil 3 wound around the winding shaft 14d affects the characteristics of the sensor, it is necessary to perform stable aligned winding so as to avoid occurrence of winding disturbance. For this reason, the case 14 is designed to prevent a step from occurring between adjacent windings due to the start end 3 a of the coil 3.
The yarn path portion 14e is provided at the front side to release the wire diameter width of one winding in advance. Further, at the time of winding, the winding wall 21 is applied to the winding shaft 14d to further stabilize the winding state.

After winding, the printed circuit board 17 is mounted,
The connection terminals 15 and 16 are soldered, and the core is attached to complete the assembly. In such an assembly, the winding is performed by an automatic winding machine, and the soldering is performed by using the coil 3 and the connection terminals 15.
16 and the printed circuit board 17 are collectively automated by a solder dipping bath, thereby enabling a series of automation. In dip soldering, it is necessary to select a material having high heat resistance for the case 14 in order to prevent thermal deformation when passing through the solder dip layer. Specific examples include polyphenylene sulfide, polypropylene, polybutylene phthalate, and polycarbonate.

As described above, according to the present embodiment, since the coil 3 is directly wound around the case 14, the work of fixing the coil 3 and the case 14 becomes unnecessary, and the cost can be reduced. In addition, by forming the passage 9 of the detection object 8 by the case 14, the distance between the sensor and the detection object 8 can be reduced, and the sensitivity of the sensor can be increased. Further, since the connection terminals 15 and 16 are provided on the case 14, the conductive connection terminals 1 are provided.
The starting end 3a and the ending end 3b of the coil 3 can be wound around the coils 5 and 16 by an automatic machine, and the printed circuit board 17 can be automatically dip-soldered for the wiring of the sensors.

In the embodiment of the present invention, the coil 3
Is wound directly on the case 14, but the coil 3 may be fixed to the case 14 as an air-core coil. The same effect that the sensitivity of the sensor can be increased and the assembly can be made more efficient can be obtained, and the air-core coil can be manufactured in large quantities at low cost by an automatic winding machine.

Further, even if the coil 3 is wound around a bobbin and fixed to the case 14, the same effect that the efficiency of assembly can be improved can be obtained. By molding the case 14 and the bobbin with a resin, the coil 3 and the case 14 can be fixed to each other by resin, and the reliability of the fixing can be improved.

(Embodiment 3) FIG. 3 is a sectional view showing the vicinity of a metal identification sensor according to Embodiment 3 of the present invention. In FIG. 3, the metal identification sensor of the present embodiment
, A first coil 23 fixed to one side surface 22 a of the cylindrical body 22, and an E-shaped first core 24 provided through the coil 23.
And the first coil 2 on the other side surface 22 b of the cylindrical body 22.
3 and a second core 26 having an E-shape provided through the coil 25.
It is composed of

With the above configuration, the first coil 23 and the second coil 25 are connected in series, the outputs of the first coil 23 and the second coil 25 are added, and the detection object 8 is formed. Can be measured from both sides. The output of each of the coils 23 and 25 is affected by the position of the detection object 8 in the passage 9 and causes a decrease in measurement accuracy. However, when the measurement is performed from both sides, this effect is canceled out, and the measurement accuracy is high.

As described above, according to the present embodiment, a high identification accuracy can be obtained without being affected by the position of the detection object 8 in the passage 9.

(Embodiment 4) FIGS. 4 (a) and 4 (b) are perspective views of essential parts for explaining the operation of a metal identification sensor according to Embodiment 4 of the present invention. In FIG. 4, the metal identification sensor according to the present embodiment includes a shaft 27 and a spring 28.
, And constitutes a passage with the input port 29 for the detection object.
And second side walls 30 and 31, a first coil (not shown) fixed to the first side wall 30, a first core (not shown) provided through the coil, A second coil (not shown) fixed to the second side surface 31 so as to face the first coil, a second core (not shown) provided through the coil, and a spring. First side wall 3 with 33
And an opening / closing lever 32 attached to the rotating shaft 30a of the first side wall 31. When the opening / closing lever 32 is depressed, the pressing surface 32 contacts a sliding surface 31a formed at the end of the second side wall 31.
a.

With the above structure, the opening / closing lever 32 is normally operated by the spring 33 as shown in FIG.
The pressing surface 32a does not contact the sliding surface 31a of the second side wall 31. Therefore, the second side wall 31 is pressed by the spring 28 and fitted to the first side wall 30. Then, when the opening / closing lever 32 is pushed down, as shown in FIG. 4B, the pressing surface 32a of the opening / closing lever 32 is
The first side wall 30 is opened from the first side wall 30 by contact with the first sliding surface 31a.

As described above, according to the present embodiment, since the passage is formed by the first side wall 30 and the second side wall 31, the side surface of the passage can be separated at the time of repair or the like. . Further, since the side wall is provided with opening / closing means, the passage can be easily opened / closed when a detection object or the like is clogged in the passage or when cleaning the passage.

The metal identification sensors of the first to fourth embodiments described above are particularly effective for identifying coins requiring high identification performance.

(Embodiment 5) FIG. 5 is a configuration diagram showing an outline of a coin identifying apparatus according to Embodiment 5 of the present invention. A coin insertion slot 29 is provided at the upper part of the coin identification device main body 34.
The coin passage 9 is connected downward from the insertion port 29. An E-shaped material sensor 35 and a thickness sensor 36 and a pot-shaped outer diameter sensor 37 are arranged on the side wall of the passage 9. The passage 9 is provided with a coin outlet 38 located at the lower part of the coin discriminating device main body 34.
It is connected to.

FIG. 6 is a block diagram showing a configuration of a control circuit of the coin discriminating apparatus according to the present embodiment. 6, the material sensor 35 is composed of two coils (not shown) arranged facing the side wall of the passage 9 and a core (not shown) provided through these coils. These coils are connected in series and in phase so that mutual inductance becomes positive, and constitute a first oscillation circuit 39. The thickness sensor 36 has the same configuration as the material sensor 35, except that two opposing coils (not shown) are connected in series and anti-phase so that mutual inductance becomes negative.
0. The outer diameter sensor 37 has the same configuration as that of the material sensor 35, and two opposing coils (not shown) are connected in series and in phase to form a third oscillation circuit 41.

The oscillating circuits 39 to 41 are connected to rectifying circuits 42 to 44 for converting an oscillating waveform from a sine wave to a signal indicating an oscillating level, respectively. The outputs of the rectifier circuits 42 to 44 enter a material detecting unit 45, a thickness detecting unit 46, and an outer diameter detecting unit 47 for detecting the maximum value of the change amount of the oscillation level when the coin passes. The detection means 45 to 47 enter the comparison circuits 48 to 50, respectively. The comparison circuits 48 to 50 are also connected to the storage circuit 51. Comparison circuits 48 to 50
Are input to a judgment circuit 52, and the judgment circuit 52 outputs a judgment signal 53.

The operation of the coin identification device configured as described above will be described. When the coin inserted from the insertion slot 29 approaches the sensors 35 to 37, the impedance of the coil changes, and accordingly, the oscillation level of the oscillation circuits 39 to 41 changes. The amount of change is formed so as to have a characteristic output mainly by the material of the coin in the material sensor 35, mainly by the thickness of the coin in the thickness sensor 36, and mainly by the outer diameter of the coin in the outer diameter sensor 37. .

The rectifier circuits 42 to 44 convert the oscillating waveforms of the oscillating circuits 39 to 41 from sine waves to signals indicating the oscillating levels. Each of the detecting means 45 to 47 detects the maximum change amount of the oscillation level during the passage of the coin. Each of the detection means 45 to 47 outputs the detected value to the corresponding comparison circuit 48 to 50, respectively. The storage circuit 51 stores a reference value for each type of genuine coin. Comparison circuit 48-
At 50, the input from each of the detection means 45 to 47 is compared with the reference of the storage circuit 51, and if they match within the allowable range, the signal indicating the type of the genuine coin is not matched with any type of reference value. Outputs a signal indicating that it is a fake coin. The determination circuit 52 outputs a signal indicating the type of genuine coin only when the signals from the comparison circuits 48 to 50 all indicate the same type of genuine coin, and otherwise determines a signal indicating a false coin. Output as signal 53.

As described above, according to the present embodiment, since the coil is fixed to the side wall of the passage, even if the depth dimension of the core changes, the distance between the detection surface and the coil does not change. Therefore, since the sensor has stable characteristics, high coin discrimination performance can be achieved.

In this embodiment, an example in which the change in the oscillation level at the time of passing a coin is used for discrimination is shown.
Changes in inductance, frequency, phase, etc. can also be used.

Also, in the first to fifth embodiments, the core is provided completely through the coil.
The core does not have to completely penetrate deep into the hollow of the coil. If at least a part of the core is inserted into the hollow of the coil, a stable sensor characteristic with respect to dimensional fluctuation of the core can be obtained as in the case where the core is completely penetrated.

Further, although examples of the core shape of the E type and the pot type have been described, the present invention is not limited to these shapes, and other shapes such as a drum type and a U type can also be used.

[0047]

As described above, according to the present invention, a case constituting a detection surface, a coil fixed to the case,
Since it has a core provided through the coil,
Even if the depth dimension of the core changes, the distance between the detection surface and the coil does not change because the coil is fixed to the case.
Therefore, stable sensor characteristics can be obtained with respect to the dimensional variation of the core.

Further, since an inexpensive core which does not require a grinding step which requires a production cost can be used, the cost of the sensor can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view near a metal identification sensor according to a first embodiment of the present invention.

2A is a plan view showing the vicinity of a metal identification sensor according to a second embodiment of the present invention, and FIG. 2B is a cross-sectional view taken along line AA in FIG. 2A.

FIG. 3 is a cross-sectional view near a metal identification sensor according to a third embodiment of the present invention.

FIG. 4A is a perspective view of a main part for describing an operation when a side wall of a coin passage of the metal identification sensor according to Embodiment 4 of the present invention is closed, and FIG. 4B is a coin passage of the metal identification sensor. Perspective view for explaining the operation when the side wall of the device is opened

FIG. 5 is a configuration diagram showing an outline of a coin identification device according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a control circuit of the coin identification device.

FIG. 7 is a cross-sectional view of a conventional metal identification sensor.

[Description of Signs] 1 Case 1a Detection surface 2 Core 3 Coil 8 Detected object 9 Passage

Claims (10)

[Claims] 1. A metal identification sensor having a case constituting a detection surface, a coil fixed to the case, and a core provided through the coil. 2. The metal identification sensor according to claim 1, wherein the coil is an air-core coil. 3. The metal identification sensor according to claim 1, wherein the coil is wound around a bobbin. 4. A coil is directly wound around a case.
2. The metal identification sensor according to 1. 5. The metal identification sensor according to claim 1, wherein a passage for a detection object is constituted by a case. 6. The metal identification sensor according to claim 1, wherein a connection terminal is provided on the case. 7. A passage for a detection object, a first coil fixed to one side surface of the passage, a first core penetrating the coil, and a first core provided on the other side surface of the passage. A metal identification sensor having a second coil fixed to face the first coil and a second core provided through the coil. 8. The metal identification sensor according to claim 7, wherein the passage includes a first side wall and a second side wall. 9. The metal identification sensor according to claim 8, further comprising means for opening and closing the side wall. 10. A coin insertion slot, a coin passage connected to the coin insertion slot, a coin identification sensor disposed on a side wall of the coin passage, and characteristics of the coin inserted by an output of the coin identification sensor. Detection circuit, a storage circuit for storing in advance data serving as a reference for authenticity and type of coins, a comparison circuit for comparing the output of the detection means with reference data of the storage circuit, and this comparison circuit And a determination circuit for determining the authenticity and type of the coin based on the comparison result of
A coin identification device using the metal identification sensor according to any one of claims 1 to 9 as the coin identification sensor.