JP2003084071A - Equipment for detecting metal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow balance of induced voltages in bi-axial two-pairs of respective detecting heads to be regulated easily. SOLUTION: This metal detecting equipment having coaxial detection heads 30 and opposed type detection heads 40 for generating magnetic fluxes orthogonal each other is provided with the first regulation member 11 comprising a thin sheetlike magnetic substance moving with respect to the magnetic flux of the coaxial detection heads 30 in parallel to the magnetic flux generated by the coaxial detection heads 30, the second regulation member 12 comprising a thin sheetlike non-magnetic substance orthogonal to the magnetic flux generated by the coaxial detection heads 30, and moving with respect to the magnetic flux of the coaxial detection heads 30, the third regulation member 13 comprising a thin sheetlike magnetic substance parallel to the magnetic flux generated by the opposed type detection heads 40, and moving with respect to the magnetic flux of the opposed type detection heads 40, and the fourth regulation member 14 comprising a thin sheetlike non-magnetic substance orthogonal to the magnetic flux generated by the opposed type detection heads 40, and moving with respect to the magnetic flux of the opposed type detection heads 40.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal detector for detecting a metal substance mixed in an object to be inspected, and more particularly to a metal detector provided with an adjusting mechanism for adjusting the balance of magnetic flux.

[0002]

2. Description of the Related Art A metal detector determines whether or not a metal is mixed in an object to be inspected by detecting a change in the inspection magnetic field caused by the metal mixed in the object to be inspected. FIG. 3 is a diagram showing the detection principle of the detection head in the metal detector. As shown in FIG. 3, conventionally, for example, the receiving coils 32 and 33 are arranged before and after the central transmitting coil 31, and magnetic force lines parallel to the passing direction of the object W to be inspected (direction A in FIG. 3) are generated. A coaxial detection head 30 having a head coil arrangement for generation is used.

In the detection head 30, each coil 31,
In the inspection space S continuous inside 32 and 33, the induced voltages V1 having opposite phases to the receiving coils 32 and 33 that intersect with the magnetic flux due to the alternating magnetic field of the transmitting coil 31 in the center, respectively.
V2 is generated. The receiving coils 32 and 33 are arranged at the same distance with respect to the transmitting coil 31, and in the non-detection state in which the inspection object W is far from the inspection space S, the induced voltages V1 and V2 have the same magnitude and no difference. Becomes

For example, the object W to be inspected containing the metal M is
When it advances in the direction A in FIG. 3 and moves to the front receiving coil 32, the magnetic flux density in the receiving coil 32 increases, and conversely, the magnetic flux density in the receiving coil 33 decreases. Therefore, the induced voltage V1 of the receiving coil 32 becomes larger than the induced voltage V2 of the receiving coil 33. Then, when the inspected object W that has advanced to the inside of the receiving coil 33, the magnetic flux density inside the receiving coil 33 becomes larger than inside the receiving coil 32, so that the induced voltage V2 becomes larger than the induced voltage V1.
In this way, based on the change in the difference between the induced voltages V1 and V2 output from the detection head 30 (fluctuation of the magnetic field),
It is possible to determine whether or not the metal M is mixed in the inspection object W that has passed through the inspection space S.

In general, the detection head 30 is arranged so that a transfer conveyor (not shown) penetrates through the inspection space S, and is housed in a substantially box-shaped casing 35 shown in FIG. . The housing 35 is formed of a magnetic shield material such as metal (eg, aluminum alloy or stainless steel). Then, the object W to be inspected is conveyed by the conveyor to pass through the inspection space S.

In the above structure, the difference between the induced voltages V1 and V2 in the receiving coils 32 and 33 does not become 0 in the non-detection state due to an error in manufacturing / assembling, and the balance of the induced voltage may be disturbed. is there. Therefore, the metal M cannot be detected accurately. Therefore, balance adjustment is necessary. In the conventional balance adjustment, as shown in FIG. 4, a metal plate 36, which is a magnetic material or a non-magnetic material, is attached to a portion of the inspection space S of the housing 35, or a magnetic material or a non-magnetic material is provided on the outer side. The balance was adjusted by inserting the metal rod 37 (for example, a screw). The adjustment with the metal plate 36 is performed by changing the attachment position with respect to the housing 35 and fixing the position at which the induced voltage is balanced. For the adjustment with the metal rod 37, the insertion depth with respect to the housing 35 is changed and fixed at a position where the induced voltage is balanced.

[0007]

By the way, the coaxial type detection head 3 used in the above-mentioned conventional metal detector is used.
In 0, for example, with respect to the needle-shaped or thin-plate-shaped metal M, the magnetic body, which is the metal M having the above-described shape, is arranged substantially orthogonal to the magnetic flux,
Alternatively, when the non-magnetic material, which is the metal M having the above-described shape, is mixed in the object W to be inspected in an arrangement parallel to the magnetic flux, the change in the magnetic flux is small, so that the difference between the induced voltages V1 and V2 is small and the detection sensitivity decreases. I will end up. That is, the metal M mixed in the inspection object W may not be detected.

Therefore, as shown in FIG.
A biaxial two-set metal detector using a detection head 40 whose magnetic flux direction is orthogonal to 0 together with the detection head 30 can be considered. As shown in FIG. 5, the detection head 40 has, for example, a transmission coil 41 arranged above the detection head 30 and arranged side by side reception coils 42 and 43 below the detection head 30 facing the transmission coil 41. The head coil is arranged so as to generate magnetic lines of force perpendicular to the passing direction of the inspection object W (direction A in FIG. 3). The detection head 40 generates induced voltages V3 and V4 having opposite phases in the transmission coils 42 and 43 that intersect with the magnetic flux of the alternating magnetic field of the transmission coil 41 in the inspection space S. The receiving coils 42 and 43 are arranged at the same distance from the transmitting coil 41, and the induced voltages V3 and V4 have the same magnitude and no difference in the non-detection state.

In this metal detector, as shown in FIG.
The detection head 30 generates a horizontal magnetic flux, and the detection head 40 generates a vertical magnetic flux. Even if the magnetic body, which is a needle-shaped or thin-plate-shaped metal M, is arranged substantially perpendicular to the magnetic flux with respect to the magnetic flux of the detection head 30,
On the 0 side, since the arrangement is parallel to the magnetic flux, the change in the magnetic flux increases, the difference between the induced voltages V3 and V4 is large, and the detection sensitivity is good. Further, even if the needle-shaped or thin-plate-shaped metal M, which is a non-magnetic material, is arranged parallel to the magnetic flux with respect to the magnetic flux of the detection head 30, the detection head 40 side is arranged orthogonal to the magnetic flux. Therefore, the change of the magnetic flux increases, the difference between the induced voltages V3 and V4 is large, and the detection sensitivity becomes good. Thus, the detection head 40 is the detection head 3
The detection head 30 detects the metal M which is difficult to detect by 0, and the detection head 30 detects the metal M which is difficult to detect by the detection head 40.

However, in the above-described biaxial / two-pair metal detector, even if an attempt is made to balance the induced voltage of the detection head 30 by the above-mentioned balance adjustment, the influence of the induced voltage balance in the detection head 40 is obtained. It's gone. On the contrary, when the balance adjustment is attempted to obtain the balance of the induced voltage in the detection head 40, the influence of the balance adjustment makes it impossible to obtain the balance of the induced voltage in the detection head 30.
As described above, in the biaxial / two-pair metal detector, it is difficult to obtain the balance of the induced voltages of the detection heads 30 and 40.

In order to solve the above problems, the present invention provides a metal detector that forms two sets of two-axis detection heads, and can easily adjust the balance of the induced voltage of each detection head. The purpose is to provide a detector.

[0012]

In order to achieve the above object, the metal detector according to claim 1 of the present invention is an object to be inspected W.
Is a metal detector having both detection heads 30 and 40 for generating magnetic fields of two axes orthogonal to each other in an inspection space S in which is transported, and is made of a thin plate-shaped magnetic body, and the one detection head 30 is The first adjusting member 11 arranged parallel to the generated magnetic flux and movable with respect to the magnetic flux of the one detection head 30 and a thin plate-shaped non-magnetic material generate the one detection head 30. A second adjusting member 12 arranged so as to be orthogonal to the magnetic flux and movable with respect to the magnetic flux of the one detection head 30, and a thin plate-shaped magnetic body,
The third adjusting member 13 arranged parallel to the magnetic flux generated by the other detection head 40 and movable with respect to the magnetic flux of the other detection head 40, and a thin plate-shaped non-magnetic body, The fourth adjusting member 14 is disposed so as to be orthogonal to the magnetic flux generated by the detection head 40, and is movable with respect to the magnetic flux of the other detection head 40.

A metal detector according to a second aspect is the metal detector according to the first aspect, wherein the first adjusting member 11, the second adjusting member 12, the third adjusting member 13 and the fourth adjusting member 14 are provided. Is a rectangular support member 2 that does not affect the magnetic field that is movable in the moving direction.
It is characterized in that it is attached to 0.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a schematic view showing a detection head of a metal detector of the present invention, and FIG. 2 is a perspective view showing a balance adjusting mechanism. In the embodiments described below, parts that are the same as or equivalent to those of the conventional technique described above will be assigned the same reference numerals.

As shown in FIG. 1, the metal detector has two sets of respective detection heads 30 and 40 for generating magnetic fields of two axes orthogonal to each other in an inspection space S in which an object to be inspected W is transported. ing. In the present embodiment, one detection head 30 is configured as the coaxial detection head 30, and the other detection head 40
Are configured as the facing detection head 40.

The coaxial type detection head 30 has the reversely wound receiving coils 32 and 33 arranged coaxially in front of and behind the transmitting coil 31 in the center thereof, and the receiving coil 32 passes in the passing direction (see FIG. 1).
The head coil is arranged to generate magnetic lines of force parallel to the middle A direction). The coaxial detection head 30 includes the coils 3
A continuous inspection space S is formed inside 1, 32, and 33. The coaxial detection head 30 generates a magnetic flux in the left-right direction in FIG. 1 (see FIG. 5) by the alternating magnetic field of the transmission coil 31 in the inspection space S, so that the phase of each of the transmission coils 32 and 33 intersecting with this magnetic flux. Generate opposite induced voltages V1 and V2. Each receiving coil 32, 33 has
They are arranged at the same distance with respect to the transmission coil 31, and in the non-detection state, the magnitudes of the induced voltages V1 and V2 are equal and the difference is 0.

The opposed type detection head 40 has a transmission coil 41 arranged on one side (upper side) of the coaxial type detection head 30, and the coaxial type detection head 30 is opposed to the transmission coil 41.
Receiving coils 42 and 43 are arranged side by side on the other side (lower side) to form a head coil arrangement for generating magnetic force lines orthogonal to the passing direction of the object W to be inspected (direction A in FIG. 3). .
The opposed detection head 40 forms the inspection space S between the transmission coil 41 and the reception coils 42 and 43. The opposed detection head 40 generates a magnetic flux in the vertical direction (see FIG. 5) in FIG. 1 by the alternating magnetic field of the transmission coil 41 in the inspection space S, so that the transmission coils 42 and 43 that intersect the magnetic flux are phased with each other. Is the reverse induced voltage V3, V
4 is generated. The receiving coils 42 and 43 are arranged at the same distance from the transmitting coil 41, and the induced voltages V3 and V4 have the same magnitude and no difference in the non-detection state. In the inspection space S, the opposed detection head 40 generates a magnetic flux that is orthogonal to the magnetic flux of the coaxial detection head 30.

Each of the detection heads 30 and 40 is arranged so that a transporting means such as a transporting conveyor (not shown) penetrates through the inspection space S, and is housed in a substantially square V-shaped casing 35 shown in FIG. To be done. The housing 35 is formed of a magnetic shield material such as metal (eg, aluminum alloy or stainless steel). Then, the object W to be inspected is conveyed by the conveyor to pass through the inspection space S.

In the metal detector of the above construction, in the coaxial type detection head 30, when the object W to be inspected containing the metal M advances in the direction A in FIG. 1 by the conveying means and moves into the front receiving coil 32, The magnetic flux density in the receiving coil 32 increases, and conversely, the magnetic flux density in the receiving coil 33 decreases. Therefore, the induced voltage V1 of the receiving coil 32 is
3 is larger than the induced voltage V2. Then, when the inspected object W that has advanced to the inside of the receiving coil 33, the magnetic flux density inside the receiving coil 33 becomes larger than inside the receiving coil 32, so that the induced voltage V2 becomes larger than the induced voltage V1. In this way, the metal M is mixed into the object to be inspected W that has passed through the inspection space S based on the change in the difference between the induced voltages V1 and V2 output from the coaxial detection head 30 (fluctuation of the magnetic field). It is possible to determine whether or not there is.

Further, in the opposed type detection head 40, the object W to which the metal M is mixed is conveyed by the conveying means A in FIG.
And the receiving coil 42 in front of the transmitting coil 41.
When moving between and, the transmitting coil 41 and the receiving coil 42
The magnetic flux density between them increases, and conversely the magnetic flux density between the transmitting coil 41 and the receiving coil 43 decreases. Therefore, the receiving coil 4
The induced voltage V3 of 2 is larger than the induced voltage V4 of the receiving coil 43. Next, when the advanced inspection object W moves between the transmission coil 41 and the reception coil 43, the transmission coil 41
Since the magnetic flux density between the receiving coils 43 is larger, the induced voltage V4 is larger than the induced voltage V3. In this way, based on the change in the difference between the induced voltages V3 and V4 (fluctuation of the magnetic field) output from the coaxial detection head 40,
It is possible to determine whether or not the metal M is mixed in the inspection object W that has passed through the inspection space S.

That is, in the metal detector of this embodiment, when the metal M mixed in the object W to be inspected has a needle shape or a thin plate shape and is a magnetic material, the magnetic flux generated in the coaxial detection head 30 When the arrangement is substantially orthogonal, the arrangement is parallel to the magnetic flux generated in the opposed detection head 40. As a result, in the coaxial detection head 30, since the change in magnetic flux is small and the difference between the induced voltages V1 and V2 is small, the detection sensitivity of the metal M is lowered, but in the opposed detection head 40, the change in magnetic flux is large and the induced voltages V3 and V4. Since the difference is large, the detection sensitivity of the metal M becomes good. On the contrary, when the metal M of the magnetic material is also arranged in parallel with the magnetic flux generated in the coaxial detection head 30 in the shape of a needle or a thin plate, the opposed detection head 40 is used.
The arrangement is substantially orthogonal to the magnetic flux generated in. As a result, in the opposed detection head 40, since the change in the magnetic flux is small and the difference between the induced voltages V3 and V4 is small, the detection sensitivity of the metal M is lowered, but in the coaxial detection head 30, the magnetic flux is changed largely and the induced voltages V1 and V2 are reduced. Since the difference is large, the detection sensitivity of the metal M becomes good.

Further, in the metal detector of this embodiment,
When the metal M mixed in the object W to be inspected has a needle shape or a thin plate shape and is a non-magnetic material and is arranged parallel to the magnetic flux generated in the coaxial detection head 30, the opposed detection head 40 is used.
The arrangement is substantially orthogonal to the magnetic flux generated in. As a result, in the coaxial detection head 30, since the change in magnetic flux is small and the difference between the induced voltages V1 and V2 is small, the detection sensitivity of the metal M is lowered, but in the opposed detection head 40, the change in magnetic flux is large and the induced voltages V3 and V4. Since the difference is large, the detection sensitivity of the metal M becomes good. Conversely, it is also needle-shaped or thin-plate shaped, and
When the non-magnetic metal M is arranged substantially orthogonal to the magnetic flux generated in the coaxial detection head 30, the opposed detection head 4
The arrangement is parallel to the magnetic flux generated at 0. As a result, in the opposed detection head 40, since the change in the magnetic flux is small and the difference between the induced voltages V3 and V4 is small, the detection sensitivity of the metal M is lowered, but in the coaxial detection head 30, the magnetic flux is changed largely and the induced voltages V1 and V2 are reduced. Since the difference is large, the detection sensitivity of the metal M becomes good.

As described above, the metal detector described above uses both the coaxial type detection head 30 and the opposed type detection head 40 whose magnetic fluxes are orthogonal to each other, so that the metal M ( Even if it is a magnetic substance or a non-magnetic substance, it is detected by the other detection head, and the metal M mixed in the inspection object W is detected without exception.

In the metal detector having the above-mentioned structure, the difference between the induced voltages V1 and V2 in the receiving coils 32 and 33 does not become zero in the coaxial detection head 30 in a non-detection state due to an error in manufacturing and assembly. , In the opposite detection head 40, the induced voltages V3 and V4 in the receiving coils 42 and 43
May not be 0, and the balance of the induced voltage may be out of balance. As a result, the metal M cannot be detected accurately, and balance adjustment is required.

The metal detector of the present embodiment has the following balance adjusting mechanism. As shown in FIGS. 1 and 2, the balance adjusting mechanism includes a first adjusting member 11, a second adjusting member 12, a third adjusting member 13, and a fourth adjusting member 1.
4 and.

First adjusting member 11 and third adjusting member 13
Is a thin plate-shaped magnetic metal body (for example, iron). The second adjusting member 12 and the fourth adjusting member 14 are made of a thin plate-shaped nonmagnetic metal body (for example, aluminum alloy or stainless steel). Each adjustment member 11, 12, 13, 14 is attached to each support member 20. Each support member 20
Is formed by molding a transparent body, such as a synthetic resin material, which is a transparent body against electromagnetic fields that does not affect the magnetic field into a rectangular shape.

The first adjusting member 11 is the coaxial type detecting head 3
It is attached to the upper surface of the support member 20 so as to be parallel to the magnetic flux in the left-right direction in FIG. 1 (see FIG. 5) in which 0 is generated. Further, the second adjusting member 12 includes the coaxial detection head 30.
1 is attached to the side surface of the support member 20 so as to be orthogonal to the magnetic flux in the left-right direction (see FIG. 5) in FIG.
The third adjusting member 13 is attached to the side surface of the support member 20 so as to be parallel to the magnetic flux generated by the opposed detection head 30 in the vertical direction in FIG. 1 (see FIG. 5). The fourth adjustment member 14 is attached to the upper surface of the support member 20 so as to be orthogonal to the magnetic flux generated by the opposed detection head 30 in the vertical direction in FIG. 1 (see FIG. 5). This makes it possible to easily obtain the above-mentioned arrangement of the adjusting members 11, 12, 13, 14 with respect to the magnetic flux of the detection heads 30, 40.

The supporting members 20 to which the adjusting members 11, 12, 13 and 14 are attached are arranged on a base 21 which is housed and fixed in a recess 35a on the bottom surface of the housing 35. As shown in FIG. 2, each support member 20 has a base 2
When the adjusting screws 22 rotatably provided are screwed into the fixed piece 21a that is erected at 1, the adjusting screws 22 move on the base 21 when the adjusting screws 22 rotate. That is, the adjustment members 11 and 12 are movable with respect to the magnetic flux of the coaxial detection head 30 by the rotation of the adjustment screws 22, and the adjustment members 13 and 14 are detected by the rotation of the adjustment screws 22 in the opposed type. It is movable with respect to the magnetic flux of the head 40. The base 21, the fixing piece 21a, and the adjusting screw 22 are made of, for example, a synthetic resin material that is a transparent body against electromagnetic fields that does not affect the magnetic field, like the support member 20.

In adjusting the balance, for example, the adjustment member 11, 12 is first applied to the coaxial type detection head 30.
To move. Next, it is applied to the opposed detection head 40,
The adjustment members 13 and 14 are moved.

The first adjusting member 11, which is a magnetic metal body parallel to the magnetic flux of the coaxial type detection head 30, changes the magnetic flux of the coaxial type detection head 30 by its movement, but the magnetic flux of the opposed type detection head 40 is changed. Since it is orthogonal to, it does not change much. Further, the second adjusting member 12 which is a non-magnetic metal body orthogonal to the magnetic flux of the coaxial type detecting head 30 changes the magnetic flux of the coaxial type detecting head 30 by its movement, but the magnetic flux of the opposing type detecting head 40 is changed. Since it is parallel to, it does not give a big change. Thereby, each adjustment member 11, 12
Is moved, the balance adjustment of only the coaxial detection head 30 is performed, and the induced voltage of the coaxial detection head 30 can be balanced without affecting the magnetic flux of the opposed detection head 40. is there.

The third adjusting member 13, which is a magnetic metal body parallel to the magnetic flux of the opposed detection head 40, changes the magnetic flux of the opposed detection head 40 by its movement, but the coaxial detection head 30 Since it is orthogonal to the magnetic flux of, it does not give a large change. Further, although the fourth adjusting member 14 which is a non-magnetic metal body orthogonal to the magnetic flux of the opposed detection head 40 changes the magnetic flux of the opposed detection head 40 due to its movement, the magnetic flux of the coaxial detection head 30 changes. Since it is parallel to, it does not give a big change. Thereby, each adjusting member 1
When moving 3 and 14, the opposed detection head 40
It is possible to balance the induced voltage of the opposing detection head 40 without affecting the magnetic flux of the coaxial detection head 30 by performing only the balance adjustment.

It should be noted that it is not necessary to move all the adjusting members 11, 12, 13, 14 in order to adjust the balance of the detecting heads 30, 40.
2, 13, 14 may be selected and moved.

Further, in the above-described embodiment, the structure for moving the respective support members 20 to which the respective adjustment members 11, 12, 13, 14 are attached is not limited to the above-mentioned structure. Various configurations are conceivable, such as fixing the member 20 with a screw through an elongated hole or a large hole provided in the base 21 and moving the screw by loosening the screw.

[0034]

As described above, the metal detector according to the present invention is the first adjusting member which is a magnetic body parallel to the magnetic flux of one detection head, and the non-magnetic body which is orthogonal to the magnetic flux of one detection head. By the movement of the second adjusting member, balance adjustment of only one detection head is performed without affecting the magnetic flux of the other detection head. In addition, the movement of the third adjustment member, which is a magnetic body parallel to the magnetic flux of the other detection head, and the fourth adjustment member, which is a non-magnetic body orthogonal to the magnetic flux of the other detection head, affects the magnetic flux of one detection head. The balance adjustment of only the other detection head is performed without giving the above. This makes it possible to easily adjust the balance of the induced voltages of the two detection heads of the two biaxial axes.

If the first adjusting member, the second adjusting member, the third adjusting member and the fourth adjusting member are attached to the respective supporting members that do not affect the movable magnetic field,
The above arrangement for the magnetic flux of each detection head of each adjustment member can be easily obtained.

[Brief description of drawings]

FIG. 1 is a schematic view showing a detection head of a metal detector of the present invention.

FIG. 2 is a perspective view showing a balance adjusting mechanism.

FIG. 3 is a schematic view showing a detection head of a conventional metal detector.

FIG. 4 is a perspective view showing a conventional balance adjusting mechanism.

FIG. 5 is a schematic view showing two sets of two-axis detection heads.

[Explanation of symbols]

11 ... 1st adjusting member, 12 ... 2nd adjusting member, 13 ... 3rd adjusting member, 14 ... 4th adjusting member, 20 ... Supporting member, 30
... coaxial type detection head (one detection head), 31 ... transmission coil, 32 ... reception coil, 33 ... reception coil, 40 ...
Opposed detection head (the other detection head), 41 ... Transmission coil, 42 ... Reception coil, 43 ... Reception coil.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoshi Mitani             5-10-10 Minamiazabu, Minato-ku, Tokyo Henri             Tsu Co., Ltd. (72) Inventor Shigeru Kuboji             5-10-10 Minamiazabu, Minato-ku, Tokyo Henri             Tsu Co., Ltd. F-term (reference) 2G005 CA03                 2G017 AA04 AB07 AD04                 2G053 AB01 BB03 BB11 BC02 BC11                       CA03 CA18 DB11

Claims (2)

[Claims] 1. A metal detector having both detection heads (30, 40) for generating magnetic fields of two axes orthogonal to each other in an inspection space (S) in which an object to be inspected (W) is transported, A first adjusting member (11) made of a thin plate-shaped magnetic body, arranged parallel to the magnetic flux generated by the one detection head and movable with respect to the magnetic flux of the one detection head; A second adjusting member (12) made of a non-magnetic material, arranged so as to be orthogonal to the magnetic flux generated by the one detection head and movable with respect to the magnetic flux of the one detection head; A third adjusting member (13) made of a magnetic material, arranged parallel to the magnetic flux generated by the other detection head and movable with respect to the magnetic flux of the other detection head, and a thin plate-shaped non-magnetic material And the magnetic flux generated by the other detection head Metal detector according to be arranged orthogonally to the fourth adjusting member which is movable relative to the magnetic flux of the other detection head (14), comprising the. 2. The first adjusting member (11), the second adjusting member (12), the third adjusting member (13) and the fourth adjusting member (14) are each movable in the moving direction. Each support member (2 that does not affect the generated magnetic field)
0) The metal detector according to claim 1, characterized in that it is attached to 0).