JP2578949B2 - Magnetic information reading method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel information reading method which can be preferably used in, for example, a factory automatic production line such as nuclear power, steel industry, and ceramic industry.

[Conventional technology]

FIG. 4 is a block diagram showing a conventional magnetic information reading device described in, for example, Japanese Utility Model Application Laid-Open No. 58-10151, in which (10) is a steel plate, (11) is a Hall element, and (12) is The Hall element mounting plate, (13) is a protective film.

[Problems to be solved by the invention]

A conventional information reading device is configured as described above, for example, and writes magnetic information written on a steel plate member surface into a Hall element (1).
The reading head composed of 1) and the Hall element mounting plate (12) was read down by lowering it on the steel plate (10) via the protective film (13). Since a semiconductor such as Ge, Si, InSb, InAs, and GaAs is used for the Hall element, the operating temperature is limited to about 100 ° C. Therefore, such a reading method has a drawback that information cannot be read unless the environment is 100 ° C. or less because the heat resistance of the Hall element is limited.

The present invention has been made in order to solve the above-mentioned problems.For example, in the nuclear power, steel and ceramic industries, ceramic industry, etc.
It is an object of the present invention to provide a magnetic information reading method capable of reading information even in an environment of not less than ° C.

[Means for solving the problem]

The magnetic information reading method according to the present invention uses a heat-resistant magnetic sensor with a magnetic marker in which information is magnetically written on a part of a base material at predetermined intervals by beam irradiation from a high energy density heat source. The magnetic sensor is composed of an excitation source and a magnetic detection unit, and the excitation source is coated with a permanent magnet having a Curie point of 200 ° C or higher or an insulator having a continuous usable temperature of 200 ° C or higher. It consists of windings, and the continuous detection temperature is 200
It consists of a winding covered with an insulator at a temperature of at least ° C.

[Action]

In the information reading method according to the present invention, information is magnetically written on the base material of the magnetic marker by beam irradiation from a high energy density heat source, and the magnetic sensors each have heat resistance of 200 ° C. or more. Since it is composed of the excitation source and the magnetic detection unit, information can be read even in an environment of 100 ° C. or higher.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view illustrating a magnetic marker reading method as a magnetic information reading method according to an embodiment of the present invention. In the figure, (1) is a heat-resistant steel plate as a base material, for example, an austenitic stainless steel plate (for example, JIS G 4305 SUS304). (2) is an information element formed by irradiating a high energy density heat source, and is formed on the base material (1) at predetermined intervals. (3) is a magnetic sensor composed of an excitation source and a magnetic detection unit. As the excitation source, a rare earth element such as an alnico-based permanent magnet mainly composed of Fe, Al, Ni, and Co, or Sm, Nd, etc. And a permanent magnet having a Curie point of 200 ° C. or higher. The magnetic detection unit is a detection winding coated with an insulator having a maximum continuous use temperature of 200 ° C. or more, such as a silicon resin, a Teflon resin, a polyiside resin, and a ceramic.

FIG. 2 is a block diagram showing a circuit of the magnetic information reading apparatus according to the present invention. (4) is an amplifier circuit,
(5) is a pulse shaping circuit, (6) is a pulse counting circuit, (7) is a computer, (8) is a terminal, and (9) is a sensor driving circuit.

FIG. 3 is a diagram showing magnetic information detected by the method of FIG. 1. The vertical axis represents the output voltage of the amplifier circuit (4) in FIG.
The displacement is on the horizontal axis.

Next, the operation of the magnetic information reading method of this embodiment will be described. In FIG. 1, although the base material (1) is essentially austenitic stainless steel and thus has essentially no magnetism, the base material is irradiated with, for example, a laser beam from a high energy density heat source to melt a part of the base material, thereby forming a ferrite structure. This portion is used as an information element (2) because it precipitates and produces magnetism. Various types of information are obtained by arbitrarily combining information elements magnetically written by irradiating a laser beam. The magnetic marker thus obtained has a Curie point of 100 ° C. or higher and has heat resistance. When the heat-resistant magnetic sensor (3) moves the information element portion of the marker, the magnetic flux generated from the permanent magnet changes, and a voltage is generated in the detection winding.
As shown in FIG. 3, the relationship between the output voltage and the amount of displacement corresponding to the position of the information bit is obtained as shown in FIG. Read information by computer (7)
To process the information and output the information to the outside at the terminal (8),
Alternatively, the sensor is driven by the sensor drive circuit (9).

In this way, the portion of the base material not irradiated with the laser beam has almost no magnetism, and the portion irradiated with the laser beam has magnetism, so it can be used as an information element,
Arbitrary information can be recorded by arbitrarily selecting the presence or absence of laser beam irradiation, necessary information is written in a symbolized pattern, and the written information is stored in a permanent magnet as shown in FIG. A heat-resistant magnetic sensor in which a detection winding arranged to detect a magnetic flux from a permanent magnet is combined, and can be detected based on a relationship between an output voltage and a displacement amount, for example, as shown in FIG. Can be read.

By the way, in the above embodiment, the case where the heat-resistant magnetic sensor in which the permanent magnet and the detection winding are combined is used is described. A winding coated with an insulator having a use temperature of 200 ° C. or more may be used.

The information to be recorded is, of course, arbitrary. If this magnetic marker is attached to a product in the course of manufacture and the information is read by a heat-resistant magnetic sensor, the coded name of the article, the color and size of the paint to be painted in the next process Various types such as shape, lot number, date of manufacture, and the like can be given.

In addition, the magnetic information reading method according to the present invention enables high-sensitivity detection using magnetism, so that the surface of the base material (1) is coated, for example, after the surface of the base material (1) is structurally connected to the detection element. The information can be read even when the information cannot be brought into close contact.

In this embodiment, the information is written by a combination of elements. However, by selecting the beam width of the laser beam to a desired value, the information can be arbitrarily changed within a range of, for example, several tens μm to several cm. The molten portion formed by the beam irradiation may be formed in a bar shape, and may have the same code system as an existing bar code. Further, the element may be formed in a circular shape and used as information bits to obtain binary information.

Further, in this embodiment, a nonmagnetic austenitic stainless steel (SUS3) is used as the base material (1) of the magnetic marker.
04), but ferromagnetic materials and ceramics composed of other iron-based steels, alloys such as zinc, chromium, nickel, manganese, and aluminum may be used. Any material can be used as long as the magnetic properties of a part of the base material are changed by the beam irradiation. Further, a part of the base material does not have to be melted by the beam irradiation, and the magnetic properties of a part of the base material may be changed by heating by the beam irradiation and cooling after the beam irradiation.

Furthermore, information may be directly magnetically written on the product by using the product itself during manufacture as a magnetic marker.

〔The invention's effect〕

As described above, according to the present invention, a part of the base material of the magnetic marker is magnetically written by changing the magnetic characteristics at predetermined intervals by beam irradiation from a high energy density heat source, and information is magnetically written. Information is read by a heat-resistant magnetic sensor composed of an excitation source and a magnetic detection unit, each of which has a heat resistance of 200 ° C or more. However, there is an effect that information can be read with high sensitivity and reading accuracy is high.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a magnetic information reading method according to an embodiment of the present invention. FIG. 2 is a block diagram showing a circuit of a magnetic information reading apparatus according to an embodiment of the present invention.
FIG. 4 is a characteristic diagram showing the relationship between the output voltage and the displacement of the heat-resistant magnetic sensor according to one embodiment of the present invention, and FIG. 4 is a configuration diagram showing a conventional magnetic information reading device. (1) ... substrate, (2) ... information element, (3) ...
... heat-resistant magnetic sensor. In the drawings, the same reference numerals indicate the same or corresponding parts.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideo Ikeda 8-1-1 Tsukaguchi Honcho, Amagasaki City, Hyogo Prefecture Inside the Materials Research Laboratory, Mitsubishi Electric Corporation (72) Inventor Shunji Omura 8-1-1 Tsukaguchi Honcho, Amagasaki City, Hyogo Prefecture No. 1 Inside Mitsubishi Electric Corporation Materials Research Laboratory (72) Inventor Yoshihiro Sugiyama 8-1-1, Tsukaguchi Honcho, Amagasaki City, Hyogo Prefecture Inside Mitsubishi Electric Corporation Materials Research Laboratory (72) Inventor Masaharu Moriyasu 8-chome Honcho, Amagasaki City, Hyogo Prefecture No. 1-1 Inside Mitsubishi Electric Corporation Production Technology Research Laboratory (72) Inventor Masayuki Kaneko 8-1-1 Tsukaguchi Honcho, Amagasaki City, Hyogo Prefecture Inside Mitsubishi Electric Corporation Production Technology Research Laboratory (72) Inventor Seigo Hiramoto Amagasaki, Hyogo Prefecture Ichizukaguchi Honcho 8-1-1 Mitsubishi Electric Corporation Production Technology Laboratory

Claims (1)

(57) [Claims] 1. A magnetic information reading method for reading magnetic information of a magnetic marker formed by changing a magnetic property of a part of a base material at a desired interval from a high energy density heat source by a magnetic sensor, wherein the magnetic sensor is excited. The excitation source is composed of a permanent magnet having a Curie point of 200 ° C. or higher or a winding covered with an insulator having a continuous usable temperature of 200 ° C. or higher. A magnetic information reading method comprising a winding covered with an insulator having a continuous usable temperature of 200 ° C. or higher.