JPH11175792A - Surface shape detection sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the surface shape of an object body made of metal, etc. SOLUTION: A surface shape detection sensor 1 is constituted by arranging the tip 3a of a rod type core 3 so as to move while facing the surface of an uneven metallic body 10 to be measured and providing the rod type core 3 with a detecting means 4 for detecting magnetic flux varying owing to the uneven shape of the body 10 to be measured. In this case, the width (w) of the tip 3a regarding the relative movement direction of the rod type core 3 is made smaller than the width of the uneven shape to be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface shape detecting sensor capable of detecting the uneven shape of the surface of an object to be measured.
More specifically, the present invention relates to a non-contact type surface shape detection sensor.

[0002]

2. Description of the Related Art Conventionally, as a sensor for detecting the surface shape of an object to be measured, an apparatus for detecting irregularities by tracing the surface with a probe, for example, may be used. Further, there has been proposed a means for incorporating information on the uneven shape of the measured object using image data obtained by photographing an image of the measured object.

[0003] In addition, for example, in discriminating the counterfeit of a coin, it is preferable to determine the authenticity of the coin by detecting the pattern, unevenness or material of the surface of the coin. For this reason, more data on the surface shape can be collected by combining a plurality of sensors. For example, a large coin discriminator has a sensor (an eddy current type) that detects a difference in eddy current loss due to a difference in resistivity depending on a metal material in order to electrically determine the authenticity and type of the coin. Sensor) is used. Discrimination data of coins obtained using a conventional eddy current sensor includes material, diameter,
The thickness and the like are the main ones, and the authenticity / type of the coin is determined by combining these data.

As another sensor for obtaining data relating to the surface shape, for example, means for electrically detecting data relating to a material and the like so as to obtain data has been proposed. The electric detection means includes, for example, a sensor in which a coil is wound around a core and a change in magnetic flux can be detected through a change in current flowing through the coil. According to such an electrical detection means, data such as the material, length, and thickness of the object to be measured can be obtained by detecting a current change or the like caused by the uneven shape. The object to be measured is, for example, a coin, and from the data such as the material obtained in this way, or by combining these data, the material and the type of the object to be measured, and furthermore, the authenticity is determined. I have.

[0005]

However, since the probe traces the surface shape of the object to be measured while making contact with it, it is difficult to collect much data instantaneously, and it takes a certain amount of time to detect the surface unevenness. Resulting in. On the other hand, according to the imaging means, image data in which the unevenness of the surface of the object to be measured is captured in a plane can be obtained instantaneously, but since the data is flat, the presence or absence of the unevenness and its size are determined. There is a problem that information cannot be obtained.

Further, according to the eddy current sensor, although data such as the material, length, and thickness described above can be obtained, information on the surface shape and unevenness of the object to be measured can be obtained depending on these data. I can't take it. For this reason, for example, when measuring and determining a coin,
Even if it is possible to discriminate the types of ordinary six coins in Japan from their materials, there is a problem that it is difficult to see counterfeit coins having almost the same outer diameter, thickness and material. Even when a sensor that can detect information about the size, weight, thickness, etc. of a coin is used in combination with an image sensor, the pattern that the outer diameter, thickness, and material are almost the same and still the same in terms of image are elaborate. There is a problem that it is difficult to determine the transferred coin and the like.

Therefore, if there is data on the surface shape obtained by detecting irregularities on the surface of the object to be measured in order to solve such a problem, it can be used as information for performing more advanced discrimination. Conceivable.

An object of the present invention is to provide a surface shape detecting sensor capable of detecting the surface shape of an object to be measured.

[0009]

In order to achieve the above object, the surface shape detecting sensor according to the first aspect of the present invention comprises:
Along with the distal end of the rod-shaped core relatively movably facing the surface of the metal object to be measured having irregularities, a detecting means for detecting the magnetic flux that changes due to the irregular shape of the object to be measured is provided in the rod-shaped core, The width of the tip in the relative movement direction of the rod-shaped core is set to be smaller than the width of the uneven shape to be detected.

Therefore, as the rod-shaped core and the object to be measured move relative to each other, the uneven shape of the object to be measured facing the tip of the rod-shaped core changes, and as a result, the magnetic flux generated at the tip of the rod-shaped core also changes. . This change is detected by the detecting means and recognized as a pattern represented by a waveform. At this time, since the width of the tip of the rod-shaped core is formed smaller than the width of the detected unevenness of the measured object, the magnetic flux that changes due to the change in the unevenness can be detected. Therefore, the change pattern is composed of fine waveforms, and is grasped as data indicating a characteristic proportional to the surface shape of the measured object as a pattern graphic.

In the surface shape detecting sensor according to the present invention, the detecting means is a detection coil wound around the rod-shaped core or a magnetoresistive element attached to the rod-shaped core. Therefore, the magnetic flux that changes due to the uneven shape of the surface of the object to be measured can be detected by changing the current of the detection coil or by changing the internal resistance of the magnetoresistive element.

In the surface shape detecting sensor according to the third aspect of the present invention, an auxiliary core for forming a magnetic flux path is disposed on both sides of the rod-shaped core, and an exciting coil is wound around the rod-shaped core or the auxiliary core. Like that. Therefore, the path of the magnetic flux generated from the tip of the core is secured, the accuracy is improved, and the sensitivity as the surface shape detecting sensor is improved.

[0013] In the surface shape detecting sensor according to the fourth aspect, an exciting coil is wound around the rod-shaped core.
A high frequency signal is applied to the exciting coil. Therefore, the rod-shaped core is excited by the high-frequency signal, and a magnetic flux is generated at the tip of the rod-shaped core facing the surface of the measured object.
Then, the magnetic flux that changes due to the uneven shape when the measured object relatively moves is detected.

[0014] In the surface shape detection sensor according to the fifth aspect, the auxiliary core is formed of a core body integrally formed with the rod-shaped core. Therefore, the path of the magnetic flux generated from the tip of the core is secured, the accuracy is improved, and the sensitivity as the surface shape detecting sensor is improved.

In the surface shape detecting sensor according to the present invention, the object to be measured is a coin, and the width of the tip in the moving direction of the rod-shaped core is 2 mm or less. Therefore, a change in the uneven shape of the coin surface, particularly a change in the uneven shape larger than 2 mm, is finely detected.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail based on an example of an embodiment shown in the drawings.

FIG. 1 shows an embodiment of the surface shape detecting sensor according to the present invention. The surface shape detection sensor 1 includes a sensor formed with a detection coil 5 and an excitation coil 6, and uses the change in magnetic flux due to the difference in material and shape to determine the material, length, It is formed so that data such as thickness can be obtained. The tip 3a of the rod-shaped core 3 forming the surface shape detecting sensor 1 is formed smaller than the width of the uneven shape so that the uneven shape of the surface of the measured object 10 can be detected.

The surface shape detecting sensor 1 is provided with a detecting means 4 for detecting a magnetic flux that changes due to the uneven shape of the measured object 10 on the rod-shaped core 3 and obtains data on the measured object 10. It is formed so that it can be. The surface shape detecting sensor 1 is arranged such that the tip 3a of the rod-shaped core 3 faces the surface of the object 10 having irregularities, and moves relative to the object 10 to be measured.

The rod-shaped core 3 in this embodiment is formed so as to have a prismatic I shape as shown in FIG. 1, and a detection coil 5 and an exciting coil 6 are wound therearound.
The I-shaped rod-shaped core 3 has a left-right direction a shown by an arrow in FIG.
Is set to be the direction of relative movement, the width w of the tip 3a in the moving direction is formed to be smaller than the width of the uneven shape to be detected. In other words, of the four sides of the tip 3a of the rod-shaped core 3, two
The length of the side is the width w and is formed small so as to improve the resolution. As a result, the uneven shape of the surface of the device under test 10 can be detected. Further, it is preferable that the width x in the direction perpendicular to the relative movement direction is formed as small as possible. That is, the tip of the rod-shaped core 3 is preferably in a pointed shape, and the resolution can be further improved as the width w is further reduced.

The detecting means 4 of the surface shape detecting sensor 1 comprises:
It is formed by a detection coil 5 wound around the rod-shaped core 3. The detection coil 5 wound around the rod-shaped core 3 is:
Further, as shown in FIG. 6, the conducting wire is connected to the amplifier circuit 11, the detection circuit 12, and the like to constitute a part of the detection circuit. The detection circuit detects the magnetic flux in the surface shape detecting sensor 1, that is, the magnetic flux that changes due to the uneven shape of the device under test 10, from the change in the current flowing through the detection coil 5, and amplifies and detects this to detect it. It is intended to be taken out as a signal. More specifically, when the device under test 10 relatively moves in the vicinity of the tip 3a of the rod-shaped core 3, the magnetic flux changes due to the uneven shape, and the current flowing through the detection coil 5 is accordingly changed. Because small changes occur in
This is amplified by the amplifying circuit 11 and then detected by the detecting circuit 12. Detection circuit 12
A peak hold circuit 13 is provided at the subsequent stage,
It is used to extract each peak of the detection signal and obtain a waveform chart in which only the extreme values are continued. The obtained waveform diagram can be used as a pattern diagram showing characteristics in proportion to the uneven shape of the surface of the device under test 10.

The exciting coil 6 is wound around the rod-shaped core 3 and excites the rod-shaped core 3 to generate a magnetic flux at its tip 3a. The exciting coil 6 in the present embodiment is the same as that shown in FIG.
As shown in FIG. 1, the surface shape detection sensor 1 is formed by being wound around the rod-shaped core 3 together with the detection coil 5. in this case,
Although the exciting coil 6 is wound coaxially outside the detection coil 5 as shown in the figure, the manner of winding is not particularly limited. However, the sensitivity increases as the distance between the detection coil 5 and the exciting coil 6 increases.
It is preferred that they are spaced apart. The exciting coil 6 is connected to the exciting circuit side as shown in FIG.
The excitation signal 14 is applied to excite the rod-shaped core 3.
The excitation signal 14 in this case is, for example, a rectangular high frequency signal as shown in the figure, and is applied so that the magnetic flux generated at the tip 3a is maintained at a constant level. As an example of the circuit used in the present embodiment, a circuit as shown in FIG. 6, that is, a circuit configured by a circuit for transmitting the excitation signal 14, a circuit for amplifying and detecting the detection signal, and the like are described.
It is needless to say that the present invention is not particularly limited to this circuit, and other exciting circuits and the like can be used.

Next, another embodiment in which the core body 2 forming the surface shape detecting sensor 1 is formed in a different shape will be described.

In the embodiment shown in FIG. 2, the rod-shaped core 3 is formed to have a cylindrical or cylindrical shape. In this case, the outer diameter d of the tip 3a of the rod-shaped core 3 is formed to be smaller than the width of the uneven shape of the measured object 10 to be detected, as in the case described above. Here, this outer diameter d
The size of (or the width w) will be described with reference to an example in which the surface unevenness of a one-yen coin shown in FIG. 7 is detected. The edge of the one-yen coin surface has the smallest width. Therefore, if the outer diameter d (or width w) of the tip 3a of the rod-shaped core 3 is made smaller than this width, all surface irregularities can be detected. However, when it is sufficient to detect the uneven shape of the pattern portion without detecting the shape of the edge portion, the tip 3a of the rod-shaped core 3 is smaller than the smallest width of the uneven shape of the pattern portion to be detected. May be reduced in outer diameter d (or width w). For example, in the case of FIG. 7B, the width of the uneven shape to be detected is
For example, the outer diameter d (or width w) may be set to a smaller value than W1 and W2. That is, the outer diameter d (width w) may be determined within a certain range of the uneven shape to be detected. Alternatively, it is only necessary to determine the width of the concave / convex shape to be detected to be detected and make the width smaller than the width. In this case, it is possible to clearly detect irregularities having a width of a size desired to be detected, but it is also possible to roughly understand shapes of irregularities having a small width which need not be detected.
The detection coil 5 is wound around the rod-shaped core 3 in an annular shape, and the exciting coil 6 is further wound therearound.

As shown in FIG. 3, auxiliary cores 7 for forming a magnetic flux path are disposed on both sides of the rod-shaped core 3 therebetween.
The exciting coil 6 may be wound around the rod-shaped core 3 or the auxiliary core 7. In this embodiment, the auxiliary cores 7 are formed on both sides of the rectangular rod-shaped core 3 so as to have an E-shape as a whole, and are formed integrally with the rod-shaped core 3 to form the core body 2.
Is composed. A detection coil 5 is wound around a central portion of the central rod-shaped core 3 to form a detection unit 4, and an excitation coil 6 is wound around the outside thereof so as to be coaxial. The size of the rod-shaped core 3 is as small as possible similarly to the rod-shaped core 3 in the above-described embodiment, and more specifically, it is, of course, smaller than the width of the uneven shape of the measured object 10 to be detected. .

Further, as a modification of the embodiment shown in FIG.
The core body 2 of the surface shape detecting sensor 1 can be formed as shown in FIG. That is, the core body 2 in this case is a cylindrical rod-shaped core 3 and a cylinder provided concentrically with the rod-shaped core 3, which can be obtained as a trajectory when the core 2 shown in FIG. 3 rotates about the rod-shaped core 3. Shaped auxiliary core 7
And is formed by. The exciting coil 6 is wound around the rod-shaped core 3 or the auxiliary core 7 as in the above-described embodiment.

In addition to the provision of the detecting coil 5 and the exciting coil 6 as described above, the detecting coil 5 and the exciting coil 6 may be wound around two grooves, for example. In the surface shape detecting sensor 1 in the embodiment shown in FIG. 5, return path cores 8 and 8 are provided further outside the E-shaped detection coil 5 and the excitation coil 6, and the detection coil 5
Is wound around the rod-shaped core 3, and the exciting coil 6 is further wound around the rod-shaped core 3 and the auxiliary cores 7, 7.

A series of operations in the case of detecting the surface shape of the object to be measured 10 made of, for example, metal using the surface shape detecting sensor 1 configured as described above will be described below. First, the rod-shaped core 3 is excited by applying a high-frequency excitation signal 14 to the detection coil 5 to generate a magnetic flux. At this time, the magnetic flux is maintained at a constant level by adjusting the excitation signal 14 or the like. Thereafter, the device under test 10 is relatively moved while facing the surface shape detecting sensor 1, and the tip 3 is moved.
When passing through the magnetic flux in a, the magnetic flux penetrates the DUT 10. When the measured object 10 further moves relatively, the magnetic flux at the tip 3a shows a change due to the uneven shape of the measured object 10, and thus such a change in the magnetic flux is detected by the detecting means 4. That is, since the current flowing through the detection coil 5 changes as the magnetic flux changes, the change in the magnetic flux is detected by detecting this.

In this case, a change in current in the detection coil 5 is first amplified by the amplifier circuit 11, and then a detection signal is obtained by the detection circuit 12. Here, since a waveform diagram whose amplitude changes with time is obtained, each peak of the waveform diagram is extracted by further passing through a peak hold circuit 13, and only the extreme values as shown in FIG. Get. The waveform diagram thus obtained can be grasped as a pattern figure proportional to the uneven shape of the measured object. In the waveform diagrams shown in FIG. 8 and the like, the vertical axis represents the output signal, and the horizontal axis represents the DUT 1 relative to the surface shape detection sensor 1.
0 indicates a relative position.

According to the surface shape detecting sensor 1 configured as described above, the width of the tip 3a of the rod-shaped core 3 is reduced to improve the resolution. The changing magnetic flux can be detected finely. Therefore, since data composed of finer waveforms can be obtained, the surface shape of the device under test 10 can be detected. Here, when the rod-shaped core 3 of the surface shape detecting sensor 1 is I-shaped, the width w of the tip 3a in the moving direction is formed so as to be smaller than the width of the uneven shape of the measured object 10. And its width w
The resolution of the surface shape detecting sensor 1 can be improved as the value of is reduced.

When the rod-shaped core 3 is formed in a columnar (cylindrical) shape as shown in FIG. 2, the direction of the surface shape detecting sensor 1 is lost. There is an advantage that a similar change in magnetic flux can be detected regardless of the direction in which the object 1 and the DUT 10 move relative to each other.

Further, in the case where auxiliary cores 7 for forming a magnetic flux path are arranged on both sides of the rod-shaped core 3 such that the rod-shaped core 3 and the auxiliary core 7 are E-shaped (FIG. 3). 4), since the path of the changing magnetic flux is secured, the accuracy as the surface shape detecting sensor 1 is improved, and the sensitivity is improved.

The detection coil 5 and the exciting coil 6 are
In the case of winding around each of the three grooves (FIG. 5), the sensitivity is improved because the detection coil 5 and the exciting coil 6 are provided at a distance.

Hereinafter, the surface shape detecting sensor 1 of the present invention will be described.
Will be described with reference to specific examples. Here, a case in which the surface shape detection sensor 1 is used to determine the type and authenticity of a coin will be described. At this time, when the rod-shaped core 3 of the surface shape detecting sensor 1 is I-shaped, the width w of the tip 3a in the moving direction is 2 mm or less and the width x in the vertical direction is 3 mm or less. If it is formed, it is possible to detect the characteristic pattern of the pattern and surface shape (irregularity) of coins that are usually distributed in Japan, but preferably a narrower core width can perform more precise detection. . Here, in the present embodiment, the width w in the moving direction is set to 0.5 mm. With such a shape, the rod-shaped core 3 can obtain data contributing to more detailed discrimination by finely detecting the shape of the edge of the coin or the like.

According to the surface shape detecting sensor 1 of the present invention, the surface shape of the measured object 10 can be sufficiently detected. However, the surface shape detecting sensor 1 of this embodiment for detecting coins is an auxiliary. Means acting as sensors, eg CIS
That is, an image processing device (not shown) is combined and complemented. That is, even if the data relating to the surface shape of the coin is captured by the surface shape detection sensor 1, FIG.
Since the surface unevenness is different between the method of cutting by the P line and the method of cutting by the Q line shown in (A), it may not be possible to specify the direction of the cut of the coin with respect to the coin. The device is installed in front of the surface shape detecting sensor 1 to obtain a pattern or other image data on the surface of the coin and refer to the data to obtain the surface shape detecting sensor 1.
Specifies the cut surface of the coin from which the concave / convex shape data is obtained. The means for obtaining the image data described here is not particularly limited to this. It is needless to say that such an auxiliary sensor is unnecessary if the cut can be made constant by another means, for example, a means for turning each coin in a certain direction.

In the surface shape detecting sensor 1 for detecting coins, although not shown, means for storing and holding legitimate data on the surface shape of the coin is provided, for example, at the subsequent stage of the detecting circuit. . Here, a plurality of patterns of data relating to the irregular shape of various legal coins are prepared in advance, and data corresponding to data obtained by the surface shape detecting sensor 1 is appropriately selected from these regular data and compared. . Here, a case has been described in which the waveform representing the surface unevenness is recognized as one pattern and compared with a regular shape pattern. However, the discrimination method is not particularly limited to this, and the thickness data of the central portion and the edge portion of the coin are used. It can also be used for comparison and discrimination. For example, FIG. 8 shows data representing a waveform when a surface irregularity shape of a one-yen coin is detected. From this data, information 21 relating to the difference between the height of the coin edge and the center, information 22 relating to the width of the edge, Information 23 about the diameter, information 24 about the material and thickness, etc. are obtained.

When discriminating the type of coin or the like using the surface shape detecting sensor 1, first, the pattern of the surface shape or the like is detected by CIS while relatively moving the coin, and image data used to specify the cut end of the coin. Prepare
By using this image data, it is specified which cut of the coin the data obtained by the surface shape detecting sensor 1 is. In other words, when the coin is circular, it is not known in which direction the coin has passed near the surface shape detecting sensor 1, so the coin in the image data is confirmed and the direction is specified. . When the cut direction is specified in this manner, the data corresponding to the cut or the vicinity thereof is selected from the regular data of the irregular shape of the regular coin prepared in advance, and this and the above-described waveform diagram are compared. Compare. If they match, the measured coin is recognized as being of the same type or regular as the comparison object, while if they do not match, it is recognized as being of a different type or forgery, etc. This data is used for detailed discrimination, and is used for performing coin type / authentication discrimination in more detail.

The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, in each of the above-described embodiments, the rod-shaped core 3
Instead of using the detection coil 5 wound as the detection means 4 as the detection means 4, it is possible to use the one in which a magnetoresistive effect element (MR element) is attached to the rod-shaped core 3. In this case, since the internal resistance of the magnetoresistive element changes due to the magnetic flux that changes due to the uneven shape of the surface of the device under test 10, a change in the magnetic flux can be finely detected by detecting this.

Although the surface shape detecting sensor 1 in each of the above-described embodiments has the detecting coil 5 and the exciting coil 6, a sensor provided with only one coil may be used instead. It is possible. In this case, excitation may be performed by a single coil, and a change in magnetic flux may be detected by detecting a change in inductance in the coil.

Further, in the description of the above-described embodiment, a case where a coin is used as the object to be measured 10 and irregularities or the like on the surface thereof are detected has been described.
It is needless to say that is not particularly limited to this. According to the surface shape detection sensor 1 of the present invention, it is naturally possible to detect a metal surface shape other than coins, and for example, it can also be used to detect fine scratches on the metal surface. it can. In this case, the shape of the core tip 3a
Needless to say, the size is appropriately changed and formed so as to correspond to the shape and size of a scratch or the like to be measured, and is particularly limited to those exemplified in the above-described embodiments. Never.

Further, the object to be measured is not limited to such a metal object. For example, according to the surface shape detecting sensor 1 of the present invention, a magnetic substance can also be an object. In this case, the magnetic flux generated from the core is also changed by the movement of the magnetic body (however, the change is in the direction in which the magnetic flux increases). Therefore, the change in the magnetic flux is captured to detect the uneven shape of the magnetic body. be able to. (Embodiment) FIG. 8 shows the waveform of a signal obtained by detecting the surface shape of a single coin using the surface shape detection sensor 1 of the present invention, and FIG. 9 shows the surface shape of a 500 yen coin. The waveforms of the signals obtained as described above are shown. In both examples, detection was performed using the rod-shaped core 3 formed so that the width w in the moving direction was 0.5 mm. As can be seen from these figures, the resolution of the surface shape detecting sensor 1 is improved by forming the width w of the tip 3a small, and the magnetic flux that changes due to the unevenness of the surface shape can be displayed by a fine waveform. did it. (Comparative Example) The surface shape of a 500-yen coin was detected using the rod-shaped core 3 having the same configuration as that of the above-mentioned embodiment except that the width of the tip 3a was 3 mm (FIG. 10).
As can be seen from the figure, the resolution of the surface shape detecting sensor 1 is low, so that the shape of the coin surface cannot be detected finely, and the signal shape is simply a flat signal waveform. Therefore, the characteristics of the surface shape of the coin could not be grasped in detail from this data.

[0041]

As is apparent from the above description, in the surface shape detecting sensor according to the first aspect of the present invention, the tip of the rod-shaped core is movably opposed to the surface of the metal object having irregularities. Along with, the rod-shaped core is provided with a detecting means for detecting a magnetic flux that changes due to the uneven shape of the object to be measured, and is smaller than the width of the uneven shape to detect the width of the tip in the relative movement direction of the rod-shaped core. Therefore, a change in magnetic flux can be finely detected.
This makes it possible to detect the uneven shape of the surface of the object without contact.

In the surface shape detecting sensor according to the second aspect of the present invention, since the detecting means is a detection coil wound on a rod-shaped core or a magnetoresistive element attached to the rod-shaped core, By changing the detection coil current, the magnetic flux that changes due to the surface irregularity shape,
Alternatively, fine detection can be made by changing the internal resistance of the magnetoresistance effect element. Therefore, it is possible to detect the surface unevenness of the measured object.

In the surface shape detecting sensor according to the third aspect of the present invention, auxiliary cores for forming a magnetic flux path are disposed on both sides of the rod-shaped core, and an exciting coil is wound around the rod-shaped core or the auxiliary core. Since it is rotated, a path for magnetic flux generated from the tip of the core is secured. Therefore, the sensitivity and accuracy of the surface shape detection sensor can be improved.

In the surface shape detecting sensor according to the fourth aspect of the present invention, an exciting coil is wound around the rod-shaped core, and a high-frequency signal is applied to the exciting coil. The rod-shaped core can be excited. Thus, a magnetic flux is generated, and the magnetic flux that changes due to the uneven shape of the surface of the measured object can be detected.

In the surface shape detecting sensor according to the fifth aspect of the present invention, since the auxiliary core is formed of a core body integrally formed with the rod-shaped core, the path of the magnetic flux generated from the tip of the core is secured and the accuracy is improved. And the sensitivity as a surface shape detection sensor is improved.

In the surface shape detecting sensor according to the present invention, the object to be measured is a coin, and the width of the tip in the moving direction of the rod-shaped core is 2 mm or less. Can be detected. As a result, it is possible to obtain information that can determine the type of the coin or the authenticity.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a surface shape detection sensor according to the present invention, in which a rod-shaped core is formed in a rectangular shape.

FIG. 2 is a perspective view showing another embodiment of the present invention, showing a case where a rod-shaped core is formed in a cylindrical / cylindrical shape.

FIG. 3 is a perspective view showing another embodiment of the present invention, showing a case where auxiliary cores are disposed on both sides of a rod-shaped core and the core body is formed in an E shape.

FIG. 4 is a perspective view showing another embodiment of the present invention, showing a case where auxiliary cores are provided on both sides of a rod-shaped core.

FIG. 5 is a perspective view showing another embodiment of the present invention, showing a case where a detection coil 5 and an exciting coil 6 are wound around two grooves, respectively.

FIG. 6 is a diagram showing a circuit for detecting a surface shape.

FIG. 7A is a plan view showing a difference in a cut direction when detecting a surface irregularity shape of an object to be measured (one yen coin);
(B) is a diagram showing an example of the cross section of the object to be measured and the width of the surface irregularities by the P line in (A).

FIG. 8 is a diagram showing a detection signal obtained by detecting the surface shape of a one-yen coin using the surface shape detection sensor of the present invention.

FIG. 9 is a diagram showing a detection signal obtained by detecting the surface shape of a 500 yen coin using the surface shape detection sensor of the present invention.

FIG. 10 shows a case where a conventional surface shape detection sensor is used.
It is a figure which shows the detection signal obtained by detecting the surface shape of the 0 yen coin.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface shape detection sensor 2 Core body 3 Rod core 3a Tip of rod core 4 Detecting means 5 Detection coil 6 Exciting coil 7 Auxiliary core 10 Object to be measured w Width of tip with respect to relative movement direction of rod core

Claims (6)

[Claims] 1. A tip of a rod-shaped core is relatively movably opposed to a surface of a metal object to be measured having irregularities, and a magnetic flux that changes in the rod-shaped core due to the irregular shape of the object to be measured is detected. A surface shape detection sensor provided with detection means for detecting the width of the tip of the rod-shaped core in the relative movement direction, the width being smaller than the width of the uneven shape to be detected. Detection sensor. 2. The surface shape detection sensor according to claim 1, wherein said detection means is a detection coil wound around said rod-shaped core or a magnetoresistive element attached to said rod-shaped core. 3. An auxiliary core for forming a magnetic flux passage is disposed on both sides of the rod-shaped core, and an exciting coil is wound around the rod-shaped core or the auxiliary core. 3. The sensor for detecting a surface shape according to 1 or 2. 4. The surface shape detecting sensor according to claim 1, wherein an excitation coil is wound around the rod-shaped core, and a high-frequency signal is applied to the excitation coil. . 5. The surface shape detecting sensor according to claim 3, wherein the auxiliary core is formed of a core body integrally formed with the rod-shaped core. 6. The surface shape detecting sensor according to claim 1, wherein the object to be measured is a coin, and a width of a tip of the rod-shaped core in the moving direction is 2 mm or less.