JPH079115Y2 - Metal detector - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal detecting device, and more particularly to a metal detecting device used for detecting a metal piece when an unnecessary metal piece is mixed in a raw material, material or product. Regarding

[0002]

2. Description of the Related Art Conventionally, as a device for detecting unnecessarily mixed metal pieces in raw materials, materials or products, it is practical
There is one disclosed in Japanese Patent No. 36632 (see FIG. 2). The metal detection device 116 includes a magnetic field generator 118 that generates a magnetic field on the sample conveyor 110 and a plurality of rectangular receiving coils 120a and 120b. The receiving coils 120a and 120b are the magnetic field generator 118. The sample conveyors 110 are arranged side by side in the generated magnetic field. In this way, the width direction of the sample conveyor 110 is divided into several regions, and the receiving coils 120a, 1
It is possible to identify which region in the width direction of the sample conveyor 110 the metal piece 114 has passed by arranging 20b and observing which receiving coil 120a, 120b detects when the sample 112 has passed. .

[0003]

However, the above-mentioned conventional metal detecting device 116 has the following problems.
Since the receiving coils 120a and 120b arranged in parallel are formed in a rectangular shape, two adjacent sides of the receiving coils 120a and 120b are parallel to the moving direction of the sample conveyor 110. In addition, a gap of 2 to 3 mm is always formed between the two sides of the adjacent receiving coils 120a and 120b parallel to the transport direction of the sample conveyor 110. As a result, the sample 11
When the metal pieces 114 mixed in 2 are at positions corresponding to the gap 122 in the width direction of the sample conveyor 110,
If the size of the metal piece 114 is larger than the gap 122, at least one of the adjacent receiving coils 120a and 120b can be detected, but the small metal piece 114 of less than 2 to 3 mm has the adjacent receiving coils 120a and 120b.
There is a problem that it passes through the region of the gap 122 without being detected by either of the above. Therefore, the present invention
An object of the present invention is to provide a metal detection device capable of surely detecting a metal piece unnecessarily mixed in a raw material, a material, or a product.

[0004]

In order to solve the above problems, the present invention has the following configuration. That is, in the middle of the moving path in which the sample moves, metal pieces that are provided side by side in the same plane in the width direction of the moving path and mixed in the sample that passes within a predetermined region in the width direction of the corresponding moving path are mixed. In a metal detecting device comprising a plurality of receiving coils for detecting a plurality of receiving coils and a magnetic field generator for generating a magnetic field including the plurality of receiving coils in the same magnetic field, two adjacent receiving coils have one receiving coil. It is characterized in that a virtual straight line passing through a point located on the outer circumference of the coil and closest to the other receiving coil and parallel to the moving direction of the sample is arranged so as to cross the other receiving coil. .

[0005]

[Operation] The operation will be described. Two adjacent receiving coils pass through a point located on the outer circumference of one receiving coil and closest to the other receiving coil, and a virtual straight line parallel to the moving direction of the sample crosses the other receiving coil. Since it is arranged as such, even if it is a small metal piece less than the width of the gap that occurs between the plurality of receiving coils that are arranged side by side in the width direction of the sample conveyor, the area corresponding to the receiving coil adjacent to the gap Since it always passes through at least one side, it becomes possible to reliably detect a metal piece unnecessarily mixed in the raw material, material, or product as a sample.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic plan view showing an embodiment of the present invention. First, the configuration will be described with reference to FIG. Reference numeral 10 is a sample conveyor that moves a sample 12 which is an example of a moving path. As a moving passage, other than the conveyor,
The sample 12 may be passed through a duct-shaped passage. A well-known belt conveyor is used as the sample conveyor 10, and the sample 12 placed on the belt is moved in the direction of arrow A (moving direction). Reference numeral 14 is a metal piece mixed in the specimen 12. Reference numeral 16 is a metal detection device provided in the middle of movement of the sample conveyor 10, and is provided with one magnetic field generator 18 that generates a magnetic field and is arranged in the magnetic field and in the same plane. Two receiving coils 20a,
20b, the magnetic field generator 18 is provided above the sample conveyor 10, and the receiving coils 20a, 20
b is provided below the sample conveyor 10. The shapes of the receiving coils 20a and 20b are the same as those of the adjacent receiving coils 20.
Two adjacent sides 21a and 21b of a and 20b are formed in a parallelogram which is not parallel to the moving direction of the sample conveyor, and in two adjacent receiving coils 20a and 20b, four of the receiving coils 20a and 20b are provided. Of the two vertices, virtual straight lines 26a, 26b that pass through the vertices 24a, 24b located closest to the receiving coil 20b or 20a of the other party and are parallel to the moving direction A of the sample conveyor 10 move the receiving coil 20b or 20a of the other party It is arranged to cross. 22 is a gap generated between the two receiving coils 20a and 20b arranged. The distance of the gap 22 is about 2 to 3 mm as in the conventional case.

Next, the operation will be described. The metal piece 14 mixed in the moving specimen 12 is the receiving coil 2
When the area corresponding to 0a is crossed, the metal piece 14 crosses the magnetic field received by the receiving coil 20a from the magnetic field generator 18, so that the magnetic field changes and an induced current is generated in the receiving coil 20a. When the metal piece 14 crosses the region corresponding to the receiving coil 20b, an induced current is similarly generated in the receiving coil 20b. By detecting this induced current, it is detected whether or not the metal piece 14 is mixed in the sample 12. As described above, the shape of the two receiving coils 20a and 20b arranged side by side in the width direction of the sample conveyor 10 is such that the two adjacent sides 21a and 21b of the receiving coils 20a and 20b are not parallel to the moving direction of the sample conveyor 10. In the two adjacent receiving coils 20a and 20b, which are parallelograms of the following, among the four vertices of the receiving coil 20a or 20b, the vertices 24a and 24b located closest to the receiving coil 20b or 20a of the other party are passed and By arranging the virtual straight lines 26a, 26b parallel to the moving direction A of the sample conveyor 10 so as to cross the receiving coil 20b or 20a of the partner, the metal piece 14 initially enters the area corresponding to the gap 22. Even if the metal piece 14 is moved by the sample conveyor 10 and passes through the receiving coils 20a and 20b, it is inevitable that a small amount. And also it can be made to traverse an area corresponding to one of the receiving coils. Therefore, even if the size of the metal piece 14 is smaller than the space of the gap 22, the receiving coils 20a and 20b can always detect. In the above-mentioned embodiment, the shape of the receiving coil is formed in a parallelogram shape. However, in addition to the above-mentioned embodiment, circular receiving coils may be arranged in a zigzag pattern in the width direction of the sample conveyor 10. Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and for example, the magnetic field generator and the receiving coil may be arranged on the same plane. In contrast to the embodiment, a magnetic field generator is provided below the sample conveyor,
It goes without saying that many modifications can be made without departing from the spirit of the invention, for example, the receiving coil may be provided above the sample conveyor.

[0008]

[Effect of the Invention] With the metal detecting device according to the present invention,
Two adjacent receiving coils pass through a point located on the outer circumference of one receiving coil and closest to the other receiving coil, and a virtual straight line parallel to the moving direction of the sample crosses the other receiving coil. Since it is arranged as such, even if it is a small metal piece less than the width of the gap that occurs between the plurality of receiving coils that are arranged side by side in the width direction of the sample conveyor, the area corresponding to the receiving coil adjacent to the gap Since at least one of them passes through without fail, it is possible to reliably detect a metal piece that is unnecessarily mixed in the raw material, material, or product as a sample.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing an embodiment of a metal detection device according to the present invention.

FIG. 2 is a schematic plan view of a conventional metal detection device.

[Explanation of symbols]

 10 sample conveyer 12 sample 14 metal piece 16 metal detector 18 magnetic field generator 20a, 20b receiving coil 24a, 24b vertex 26a, 26b virtual straight line A moving direction of sample conveyer

Claims (1)

[Scope of utility model registration request] 1. A sample is provided in the same plane in the width direction of the moving path in the middle of the moving path where the sample moves, and is mixed in the sample passing through a predetermined area in the width direction of the corresponding moving path. In a metal detection device including a plurality of receiving coils for detecting metal pieces present and a magnetic field generator for generating a magnetic field including the plurality of receiving coils in the same magnetic field, two adjacent receiving coils are An imaginary straight line that is parallel to the moving direction of the sample and that passes through a point located closest to the other receiving coil on the outer circumference of one receiving coil is arranged so as to cross the other receiving coil. Characteristic metal detection device.