WO2023182463A1 - Magnetic marker - Google Patents

Magnetic marker Download PDF

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Publication number
WO2023182463A1
WO2023182463A1 PCT/JP2023/011655 JP2023011655W WO2023182463A1 WO 2023182463 A1 WO2023182463 A1 WO 2023182463A1 JP 2023011655 W JP2023011655 W JP 2023011655W WO 2023182463 A1 WO2023182463 A1 WO 2023182463A1
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WO
WIPO (PCT)
Prior art keywords
magnetic marker
magnetic
hole
marker
stress
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Application number
PCT/JP2023/011655
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French (fr)
Japanese (ja)
Inventor
道治 山本
知彦 長尾
均 青山
Original Assignee
愛知製鋼株式会社
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Publication of WO2023182463A1 publication Critical patent/WO2023182463A1/en

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    • E—FIXED CONSTRUCTIONS
    • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
    • E01C1/00—Design or layout of roads, e.g. for noise abatement, for gas absorption
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D1/00—Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots
    • G05D1/02—Control of position or course in two dimensions
    • G05D1/03—Control of position or course in two dimensions using near-field transmission systems, e.g. inductive-loop type
    • G—PHYSICS
    • G08—SIGNALLING
    • G08G—TRAFFIC CONTROL SYSTEMS
    • G08G1/00—Traffic control systems for road vehicles
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F7/00—Magnets
    • H01F7/02—Permanent magnets [PM]

Definitions

  • the present invention relates to magnetic markers placed on roads to assist vehicle driving.
  • Patent Document 1 magnetic marker systems for vehicles that utilize magnetic markers placed on roads have been known (for example, see Patent Document 1). Such magnetic marker systems are intended for vehicles equipped with magnetic sensors. When a vehicle detects magnetic markers placed along the lane, various types of driving support, such as automatic steering control and lane departure warning, are realized.
  • the magnetic marker may fall off the road and the function of the magnetic marker may be lost all at once.
  • the present invention has been made in view of the above-mentioned conventional problems, and aims to provide a magnetic marker that has the possibility of maintaining its function even when pavement is damaged.
  • the present invention is a magnetic marker disposed on a road for use in driving support of a vehicle, comprising:
  • the magnetic marker is a columnar magnet having a shape where the uniformity of stress in response to an external force is impaired and a portion where stress is concentrated occurs.
  • the magnetic marker of the present invention is configured so that there are locations where stress is concentrated. This magnetic marker is more likely to break due to stress concentration than a magnetic marker, in which the stress is uniform when an external force is applied. When the magnetic marker of the present invention falls off the road, for example, the magnetic marker easily breaks and separates into a plurality of small pieces, reducing the possibility that the entire magnetic marker will immediately fall off the road.
  • the magnetic marker of the present invention has an excellent property that it is highly likely that it can maintain its magnetic performance to some extent even when it falls off the road.
  • FIG. 3 is an explanatory diagram showing magnetic markers placed on a road in Example 1.
  • FIG. 3 is a perspective view showing a first magnetic marker in Example 1.
  • FIG. 3 is a cross-sectional view of the first magnetic marker in Example 1 (a view taken along the line AA in FIG. 2).
  • FIG. 7 is an explanatory diagram showing a magnet sheet constituting another first magnetic marker in Example 1.
  • FIG. FIG. 3 is a perspective view of a second magnetic marker in Example 1.
  • a cross-sectional view of the second magnetic marker in Example 1 (a view taken along the line BB in FIG. 5).
  • FIG. 7 is an explanatory diagram showing another second magnetic marker in Example 1.
  • FIG. 3 is a perspective view showing a third magnetic marker in Example 1.
  • FIG. 7 is a perspective view showing another third magnetic marker in Example 1.
  • FIG. FIG. 7 is an explanatory diagram of a marker bar in Example 2.
  • FIG. 7 is an explanatory diagram showing how a magnetic marker is cut out from a marker rod in Example 2.
  • FIG. 7 is an explanatory diagram of the state in which the tip of the marker rod is inserted into the accommodation hole in Example 2.
  • FIG. 7 is an explanatory diagram of the first procedure for separating the magnetic marker at the tip of the marker rod in Example 2.
  • FIG. 7 is an explanatory diagram of the second procedure for separating the magnetic marker at the tip of the marker rod in Example 2.
  • FIG. 7 is an explanatory diagram of a procedure for separating the magnetic marker at the tip of the marker rod and placing it in the accommodation hole in Example 2.
  • Example 1 This example is installed on a road 3 so that it can be detected by a magnetic sensor (not shown) attached to the vehicle, and supports the driver's operation of the vehicle or realizes automatic driving that does not depend on the driver's operation.
  • a magnetic marker 1 for realizing control on the vehicle side. The contents will be explained with reference to FIGS. 1 to 9.
  • the magnetic marker 1 (FIG. 1) of this example is a buried type magnetic marker, and is installed (buried) in a state of being accommodated in a 30 mm deep accommodation hole 30 provided in the road surface 3S.
  • the magnetic marker 1 has a columnar shape with a diameter of 30 mm and a height of 20 mm. Since the height of the magnetic marker 1 is 20 mm with respect to the depth of the accommodation hole 30 mm, the upper surface of the magnetic marker 1 placed in the accommodation hole 30 is set back about 10 mm from the road surface.
  • the accommodating hole 30 is filled with a polymeric material such as asphalt or a resin material. As a result, a lid 31 made of asphalt, resin material, or the like is formed on the upper surface side of the magnetic marker 1.
  • the cross-sectional structure (not shown) of the road 3 paved with asphalt etc. roughly has a three-layer structure: a roadbed made of compacted soil, a roadbed made of granular materials such as crushed stone or crushed run, and a surface layer made of a heated asphalt mixture.
  • the heated asphalt mixture is an asphalt mixture in which coarse aggregate 331, fine aggregate 332, filler, and asphalt are mixed in a heated state.
  • the thickness of the surface layer is, for example, about 10 cm.
  • the coarse aggregate 331 is, for example, crushed stone with a particle size of 2.5 to 5 mm.
  • Fine aggregate 332 is, for example, aggregate that passes through a 2.36 mm sieve and remains on a 0.075 mm sieve.
  • the fine aggregate 332 is, for example, sand with a particle size of 0.075 to 2.36 mm.
  • the filler which is not shown, is a mineral powder that passes through a 0.075 mm sieve.
  • the filler is, for example, stone powder made from powdered limestone.
  • a pothole is a hole that occurs when a part of the surface layer made of the heated asphalt mixture peels off from the road surface 3S. Potholes occur, for example, when the connection structure between coarse aggregates 331 in the heated asphalt mixture forming the surface layer is damaged.
  • the magnetic marker 1 (FIG. 1) is a columnar permanent magnet with a diameter of 30 mm and a height of 20 mm.
  • the magnet forming the magnetic marker 1 is an isotropic ferrite plastic magnet in which iron oxide magnetic powder, which is a magnetic material, is dispersed in a polymeric material, which is a base material.
  • polymeric materials forming the magnet include asphalt, rubber, PPS (Poly Phenylene Sulfide), nylon 66, and nylon 12.
  • the magnetic marker 1 of this example may be a magnet itself. If necessary, a coating layer may be provided on the outer peripheral surface of the magnet. The magnetic marker 1 can be directly accommodated in the accommodation hole 30 provided in the road surface 3S.
  • the magnetic marker 1 of this example has magnetic properties such that the surface magnetic flux density is 45 mT (millitesla) and the magnetic flux density reaching a height of 250 mm is about 8 ⁇ T.
  • the height of 250 mm is an example of a height that corresponds to the upper limit of the expected range of mounting heights of the magnetic sensor in a vehicle.
  • the magnetic marker 1 of this example is characterized in that it is a permanent magnet with a shape in which the uniformity of stress in response to external forces is impaired, resulting in areas where stress is concentrated. In comparison with a magnetic marker that generates stress with high uniformity when an external force is applied, the magnetic marker 1 is more likely to break due to stress concentration and is more likely to separate into a plurality of small pieces.
  • stress concentration in an object tends to occur at locations where the cross-sectional area changes suddenly. If stress is concentrated when an external force is applied, excessive stress that exceeds the material strength of the constituent materials of the object is likely to occur. Naturally, compared to an object where there is no sudden change in cross-sectional area, stress is generated with high uniformity when an external force is applied, and the maximum value of stress is suppressed, an object with points where stress is concentrated is Breakage is likely to occur.
  • the magnetic marker 1 exposed on the road surface 3S remains in one piece, the magnetic marker 1 will fall off the road as a whole due to the occurrence of potholes, and the magnetic function of the magnetic marker 1 will be lost all at once. It turns out. If the magnetic marker 1 of this example has a structure that can be separated into a plurality of small pieces, it is possible to separate a part according to the enlargement of a pothole or the like, and the remaining part may remain on the road side. Therefore, there is a high possibility that the magnetic marker 1 can maintain its magnetic function to some extent.
  • the magnetic marker 1 of this example is a magnetic marker with excellent characteristics that reduces the risk of the magnetic marker losing its function of exerting magnetism on the surrounding area all at once.
  • a plurality of types of magnetic markers 1 having such characteristics are illustrated.
  • the first magnetic marker 1 is the magnetic marker shown in FIGS. 2 and 3.
  • FIG. 2 is a perspective view showing the appearance of the magnetic marker 1.
  • FIG. 3 is a cross-sectional view showing the structure of a cross section including the central axis of the columnar shape. The cross section in this figure is taken along line AA in FIG.
  • the first magnetic marker 1 is made by producing an intermediate product (not shown) in which an isotropic ferrite plastic magnet, which is a permanent magnet, is formed into a columnar shape, and then slitting the outer peripheral surface of the product.
  • a plurality of annular slits 101 orthogonal to the axial direction of the column are provided at regular intervals.
  • the width of the slit 101 which is an example of a groove, is as fine as, for example, 0.1 to 0.2 mm.
  • the inner diameter of the annular slit 101 is, for example, 5 mm.
  • the magnetic marker 1 has a structure in which a plurality of magnet sheets separated by annular slits 101 are stacked.
  • the slits 101 create areas where stress is concentrated, and cracks are likely to occur due to the slits 101.
  • the magnetic marker 1 breaks due to the crack generated in the slit 101, that is, the gap widens, and is easily separated into a plurality of small pieces.
  • This magnetic marker 1 is easily broken due to the presence of the slit 101, and the force required to separate it into a plurality of small pieces is smaller than that of the intermediate product.
  • the inside of the slit 101 may be filled with soft magnetic material powder or the like.
  • the soft magnetic material include iron, silicon iron, permalloy, and the like. It is preferable that the soft magnetic material to be filled has a lower strength than the magnet forming the magnetic marker 1 and is easily broken.
  • a polymeric material such as a resin material may be filled. Since the soft magnetic material has high magnetic permeability, deterioration in magnetic performance due to the provision of the slit 101 can be suppressed. Note that, as in this example, if the gap is about 0.1 to 0.2 mm, deterioration in magnetic performance will not be a major problem. When the gap becomes larger and the deterioration of magnetic performance becomes greater, the effectiveness of the soft magnetic material filled in the slit 101 becomes significant. It is also possible to coat the outer peripheral surface where the slit 101 is provided with a resin material.
  • the opening of the slit 101 that opens on the outer peripheral surface of the magnetic marker 1 does not need to be covered.
  • the freezing of moisture or the like that has entered the slit 101 can promote breakage triggered by the slit 101. If the magnetic marker 1 is broken in advance, there is a high possibility that a portion can be immediately separated as the pothole expands.
  • an adhesive material or adhesive material that does not harden over time is used as the adhesive material or adhesive material for joining the magnet sheets 11 in FIG. 4, adjacent magnet sheets 11 can be separated via the joining layer. It becomes easier to do.
  • an adhesive material that hardens but easily causes the bonding layer to break If the bonding layer ruptures, cracks will occur between adjacent magnet sheets and the bonding layer will break, making it easy for the magnetic marker 1 to separate into a plurality of small pieces.
  • the adhesive material is an adhesive material in the narrow sense that is in a liquid state before use and becomes solid over time.
  • the adhesive material is a semi-solid and viscous adhesive material that has both liquid and solid properties. It can also be considered that the concept of adhesive material in a broad sense includes adhesive materials and adhesive materials in a narrow sense.
  • the adhesive material or adhesive material for example, it is also possible to use an adhesive material that has relatively high strength immediately after bonding, but whose bonding strength gradually decreases due to changes over time. Further, for example, it is also possible to employ a disassembly adhesive material or a disassembly adhesive material that has some kind of disassembly factor and has the property that the bonding force decreases or the adhesive material peels off due to a disassembly operation that activates the disassembly factor.
  • Ultraviolet release tape is a tape called dicing tape in semiconductor processes.
  • it may be a water-absorbing resin-containing adhesive material that has a disassembly factor such as expansion of the water-absorbing resin and whose bonding strength is reduced by a disassembly operation such as immersion in water.
  • it may be a thermally expandable microcapsule-containing adhesive material that has a disintegration factor of microcapsule expansion and whose bonding strength is reduced by heating.
  • it may be a thermosetting/thermoplastic adhesive material that has disassembly factors such as softening and melting, and whose bonding strength is reduced by the disassembly operation of heating.
  • it may be an adhesive material that has a disassembly factor of embrittlement of the adhesive material and whose bonding strength decreases due to the embrittlement caused by heating or ultraviolet irradiation.
  • it may be a hydrolyzable adhesive material or adhesive material that has a disassembly factor called hydrolysis and whose bonding strength is reduced by the disassembly operation of supplying moisture.
  • It may be a moisture-absorbing and peelable adhesive material that has disintegration factors such as moisture absorption and softening/melting of the adhesive material, and whose bonding strength decreases when immersed in hot water.
  • it may be an electromagnetic induction/thermoplastic adhesive material that has disintegration factors such as softening and melting, and whose bonding strength is reduced by electromagnetic induction heating.
  • it may be an easily peelable adhesive material that has a disassembly factor of mechanical fracture and whose bonding strength is reduced by a disassembly operation of applying a vertical load.
  • it may be an adhesive material that has a disassembly factor called mechanical destruction and whose bonding strength decreases due to the disassembly operation called action of shear load.
  • a biodegradable adhesive material or adhesive material By using a biodegradable adhesive material that decomposes in nature, the bonding force can be gradually reduced after the magnetic marker 1 is embedded. Furthermore, if the adhesive material is biodegradable, the magnetic marker 1 can be easily disposed of, and the cost required for disposing of the magnetic marker 1 can be reduced.
  • the magnetic marker 1 After accommodating the magnetic marker 1 in the accommodating hole 30 (see FIG. 1), if the accommodating hole 30 is filled with a polymeric material such as asphalt or a resin material, the shape of the magnetic marker 1 is maintained by the polymeric material. obtain. Therefore, even if the bonding force of the bonding layer is lost over time, as long as the magnetic marker 1 remains in the accommodation hole 30, the magnetic marker 1 will not separate into a plurality of small pieces and will remain in an integrated state.
  • a polymeric material such as asphalt or a resin material
  • the second magnetic marker 1 is the magnetic marker shown in FIGS. 5 and 6.
  • FIG. 5 is a perspective view showing the appearance of the magnetic marker 1.
  • FIG. 6 is a cross-sectional view of the magnetic marker 1 perpendicular to the axial direction. The cross section in this figure is a cross section taken along line BB in FIG.
  • a plurality of horizontal holes 102 are bored in the radial direction intersecting the central axis.
  • the magnetic marker 1 is, for example, a magnetic component in which a columnar intermediate product is manufactured and then provided with a large number of lateral holes 102 passing through it in the radial direction.
  • the horizontal hole 102 is a fine hole with a diameter of about 0.5 to 1.0 mm formed by laser processing, for example.
  • the horizontal hole 102 intersects with the central axis of the cylindrical magnetic marker 1 and penetrates in the radial direction.
  • the horizontal holes 102 are along nine cross sections (hereinafter referred to as the formation surfaces of the horizontal holes 102) at 2 mm intervals in the axial direction of the magnetic marker 1.
  • the forming surfaces at both ends are each located 1 mm away from the end surface of the magnetic marker 1 in the axial direction.
  • a plurality of horizontal holes 102 are bored, for example, at equal intervals of 16 divisions (equal intervals of 22.5 degrees) in the circumferential direction (see FIG. 6).
  • the number of formation surfaces may be greater than or equal to nine locations.
  • the formation surfaces may be irregularly spaced.
  • the circumferential interval of the horizontal holes 102 on the forming surface may be finer or coarser than 16 divisions.
  • the circumferential intervals of the horizontal holes 102 may be irregular.
  • the magnetic marker 1 shown in FIGS. 5 and 6 has a structure in which cracks are likely to occur on the surface where the horizontal hole 102, which is an example of a gap, is formed, and can be separated into a plurality of small pieces.
  • This magnetic marker 1 is a magnetic marker in which magnetic sheets are laminated through the surface in which the horizontal hole 102 is formed. In this magnetic marker 1, the strength is reduced due to the presence of the surface on which the horizontal hole 102 is formed. In the magnetic marker 1, adjacent small pieces are separated via the forming surface due to the enlargement of the horizontal hole 102, which is a gap. Due to the presence of the forming surface provided with the horizontal holes 102, this magnetic marker 1 is more easily broken and separated into small pieces than the above-mentioned intermediate product. In the magnetic marker 1 shown in FIGS. 5 and 6, the cross-sectional area perpendicular to the axial direction rapidly decreases at the formation surface in the axial direction, resulting in areas where stress is concentrated.
  • the inside of the horizontal hole 102 may also be filled with a soft magnetic material. It is preferable that the soft magnetic material has a lower strength than the magnet forming the magnetic marker 1 and is easily broken. Instead of the soft magnetic material, a polymeric material such as a resin material may be filled. It is also good to provide a coating with a resin material on the outer peripheral surface where the horizontal hole 102 opens.
  • a vertical hole 103 (an example of a hole) that penetrates in the axial direction may be provided.
  • a plurality of vertical holes 103 are formed along a plane including the central axis of the magnetic marker 1.
  • the planes along which the vertical holes 103 lie are arranged at equal intervals of 45 degrees in the circumferential direction.
  • openings of the vertical holes 103 are arranged radially.
  • a columnar region with a fan-shaped cross section is formed, which is partitioned by the surface (the above-mentioned plane) in which the vertical hole 103 is formed, which is an example of a gap.
  • a vertical hole 103 (FIG. 7) may also be provided.
  • through holes are illustrated as the horizontal holes 102 and the vertical holes 103, but they may be holes with bottoms that do not penetrate through them.
  • a magnetic marker provided with a hole which is an example of a gap, has a reduced strength due to the presence of the hole and is easily broken. This magnetic marker has a structure that can be separated into a plurality of small pieces by breaking. Note that handling of the opening portions of the horizontal hole 102 and the vertical hole 103 is the same as in the case of the slit 101. It may be left open to the outside.
  • the magnetic marker 1 in FIG. 8 is a magnetic marker provided with a radial slit 131 so as to be divided into a plurality of columnar magnet regions 13 having a sector-shaped cross section.
  • the slit 131 is formed along a plane defined by the radial direction and the axial direction, avoiding the center portion 1C of the magnetic marker 1 in the radial direction. Therefore, the plurality of magnet regions 13 having a sector-shaped cross section are interconnected through the central portion 1C, which resembles the core of a pineapple.
  • the magnet region 13 having a sector-shaped cross section is only connected to the center portion 1C, and the magnet regions 13 that are adjacent to each other in the circumferential direction are adjacent to each other via the slit 131 and are not connected to each other. do not have. That is, in the magnetic marker 1 of FIG. 8, due to the presence of the slit 131, there is a portion where the radial cross-sectional area including the central axis changes suddenly in the circumferential direction, and stress is concentrated at this portion.
  • a magnetic bar corresponding to the center portion 1C of the magnetic marker described above is prepared, and a magnet piece forming the magnet area 13 is joined to the magnetic bar to form a magnetic marker similar to the magnetic marker 1 in FIG. That's good too.
  • the slit 131 may also be filled with a soft magnetic material. It is preferable that the soft magnetic material has a lower strength than the magnet forming the magnetic marker 1 and is easily broken. Instead of the soft magnetic material, a polymeric material such as a resin material may be filled. It is also good to provide a coating with a resin material on the outer peripheral surface where the slit 131 opens.
  • the slit 132 has an annular shape except for the center portion 1C.
  • a fan-shaped magnet region 135 like a piece of pizza is connected to and held at the center portion 1C.
  • the magnetic marker 1 of this example is a columnar permanent magnet that has a shape in which the uniformity of stress in response to external forces is impaired, resulting in areas where stress is concentrated.
  • This magnetic marker 1 is provided with locations where stress is concentrated so that it is less brittle than the pavement material that makes up the pavement to be constructed.
  • the coarse aggregate 331 forming the surface layer of the pavement has a particle size of, for example, 2.5 to 5 mm, while the magnetic marker 1 has a diameter of 30 mm and a height of 20 mm. If the magnetic marker is integral, there is a possibility that when a pothole occurs, the magnetic marker larger than the coarse aggregate 331 may roll out onto the road surface. On the other hand, if the magnetic marker 1 of this example has a structure that can be separated into a plurality of small pieces, there is little risk of it rolling out onto the road surface while remaining as one piece. Since this magnetic marker 1 can be separated into a plurality of small pieces, it only rolls out onto the road surface as small pieces that are the same size or smaller than the coarse aggregate 331.
  • a columnar magnetic marker with a circular cross section is illustrated.
  • the cross-sectional shape is not limited to a circular shape.
  • a columnar magnetic marker having a cross-sectional shape such as a triangular, square, or pentagonal shape may be used.
  • Example 2 This example is an example of an embodiment in which a plurality of magnetic markers can be handled integrally by utilizing a structure that can be separated into a plurality of small pieces. This example relates to a marker rod 1R in which a plurality of magnetic markers 1 of Example 1 are connected. This content will be explained using FIGS. 10 to 12(d).
  • the marker rod 1R (FIG. 10) has a connecting surface 100C that connects two magnetic markers 1 in the axial direction, and is composed of a plurality of magnetic markers 1 as a whole.
  • the connection strength between the two magnetic markers 1 on the connection surface 100C is set to be smaller than the strength required to separate each magnetic marker 1 into small pieces.
  • the connecting surface 100C becomes a cutting surface and the marker rod 1R
  • the magnetic marker 1 can be cut out from. If the amount of protrusion of the tip from the edge of the worktable 105 is set to slightly exceed the height (total length) of the magnetic marker 1, the magnetic markers 1 can be efficiently cut out one by one.
  • the marker rod 1R it is also possible to use the marker rod 1R to accommodate the magnetic markers 1 one by one in the accommodation holes 30, for example, as shown in FIGS. 12(a) to 12(d).
  • the tip of the marker rod 1R is inserted, for example, about 13 to 18 mm (less than the height of the magnetic marker 1) into the accommodation hole 30 with a diameter of 38 mm and a depth of 30 mm (Fig. 12(a))
  • the marker rod 1R is By rotating the rear end side (FIG. 12(b)), one magnetic marker 1 can be easily separated (FIG. 12(c)).
  • the magnetic marker 1 separated from the marker rod 1R in this manner falls to the bottom of the accommodation hole 30 due to its own weight and is accommodated (FIG. 12(d)).
  • a horizontal hole similar to the horizontal hole may be bored in the connecting surface 100C. While the horizontal hole in this magnetic marker 1 is formed into 16 divisions in the circumferential direction, it is preferable to form the horizontal hole in a larger number of divisions, such as 32 divisions in the circumferential direction, on the connecting surface 100C. In this case, the strength of the connecting surface 100C can be made smaller than the surface of the magnetic marker 1 on which the horizontal holes are formed.
  • Magnetic marker 1R Marker rod 100C Connecting surface 101 Slit (groove, gap) 102 Horizontal hole (hole, gap) 103 Vertical hole (hole, gap) 11 Magnet sheet 13, 135 Magnet area 131, 132 Slit (groove) 3 Road 3S Road surface 30 Accommodation hole 331 Coarse aggregate 332 Fine aggregate

Abstract

A magnetic marker (1) is disposed on a road (3) so that the magnetic marker can used for vehicular driving assistance. The magnetic marker is a columnar magnet having a shape such that stress from a force acting from the outside is caused to be non-uniform, thereby causing the generation of locations where the stress is concentrated. The magnetic marker (1) tends to split into a plurality of small pieces after being broken due to the concentration of stress. When pavement damage occurs in the periphery of the magnetic marker (1), it is possible that some of the small pieces being separated will cause the remaining small pieces to remain at the side of the road and the magnetic performance thereof will be maintained, increasing the probability that the functionality of the magnetic marker (1) can be maintained even when the pavement is damaged.

Description

磁気マーカmagnetic marker
　本発明は、車両の運転を支援するために道路に配設される磁気マーカに関する。 The present invention relates to magnetic markers placed on roads to assist vehicle driving.
　従来、道路に配設された磁気マーカを利用する車両用の磁気マーカシステムが知られている（例えば、特許文献１参照。）。このような磁気マーカシステムは、磁気センサが取り付けられた車両を対象としている。車線に沿って配設された磁気マーカを車両が検出することにより、自動操舵制御や車線逸脱警報等、各種の運転支援が実現される。 Conventionally, magnetic marker systems for vehicles that utilize magnetic markers placed on roads have been known (for example, see Patent Document 1). Such magnetic marker systems are intended for vehicles equipped with magnetic sensors. When a vehicle detects magnetic markers placed along the lane, various types of driving support, such as automatic steering control and lane departure warning, are realized.
特開２０１９－２１４８４４号公報JP2019-214844A
　しかしながら、道路の舗装の劣化が生じたときに磁気マーカが道路から脱落し、磁気マーカの機能が一気に失われるおそれがある。 However, when the road pavement deteriorates, the magnetic marker may fall off the road and the function of the magnetic marker may be lost all at once.
　本発明は、前記従来の問題点に鑑みてなされたものであり、舗装が傷んだ際にも磁気マーカの機能を維持できる可能性を有する磁気マーカを提供しようとするものである。 The present invention has been made in view of the above-mentioned conventional problems, and aims to provide a magnetic marker that has the possibility of maintaining its function even when pavement is damaged.
　本発明は、車両の運転支援に利用するために道路に配設される磁気マーカであって、
　該磁気マーカは、外部から作用する力に応じた応力の均一性が損なわれて応力が集中する箇所が生じる形状を有する柱状の磁石である磁気マーカにある。 The present invention is a magnetic marker disposed on a road for use in driving support of a vehicle, comprising:
The magnetic marker is a columnar magnet having a shape where the uniformity of stress in response to an external force is impaired and a portion where stress is concentrated occurs.
　本発明の磁気マーカは、応力が集中する箇所が生じるように構成されている。この磁気マーカは、外部から力が作用したときの応力が均一である磁気マーカと比べて、応力集中により破断し易くなっている。本発明の磁気マーカは、例えば道路からの脱落の際には、磁気マーカが破断して複数の小片に分離し易く、直ちに全体が道路から脱落するおそれが少なくなっている。本発明の磁気マーカは、道路から脱落するような状況が発生したときでも、磁気的な性能をある程度、維持できる可能性が高いという優れた特性を有する。 The magnetic marker of the present invention is configured so that there are locations where stress is concentrated. This magnetic marker is more likely to break due to stress concentration than a magnetic marker, in which the stress is uniform when an external force is applied. When the magnetic marker of the present invention falls off the road, for example, the magnetic marker easily breaks and separates into a plurality of small pieces, reducing the possibility that the entire magnetic marker will immediately fall off the road. The magnetic marker of the present invention has an excellent property that it is highly likely that it can maintain its magnetic performance to some extent even when it falls off the road.
実施例１における、道路に配設された磁気マーカを示す説明図。FIG. 3 is an explanatory diagram showing magnetic markers placed on a road in Example 1. FIG. 実施例１における、第１の磁気マーカを示す斜視図。3 is a perspective view showing a first magnetic marker in Example 1. FIG. 実施例１における、第１の磁気マーカの断面図（図２中のＡ－Ａ線矢視図）。FIG. 3 is a cross-sectional view of the first magnetic marker in Example 1 (a view taken along the line AA in FIG. 2). 実施例１における、他の第１の磁気マーカを構成する磁石シートを示す説明図。FIG. 7 is an explanatory diagram showing a magnet sheet constituting another first magnetic marker in Example 1. FIG. 実施例１における、第２の磁気マーカの斜視図。FIG. 3 is a perspective view of a second magnetic marker in Example 1. 実施例１における、第２の磁気マーカの断面図（図５中のＢ－Ｂ線矢視図。）A cross-sectional view of the second magnetic marker in Example 1 (a view taken along the line BB in FIG. 5). 実施例１における、他の第２の磁気マーカを示す説明図。FIG. 7 is an explanatory diagram showing another second magnetic marker in Example 1. 実施例１における、第３の磁気マーカを示す斜視図。FIG. 3 is a perspective view showing a third magnetic marker in Example 1. 実施例１における、他の第３の磁気マーカを示す斜視図。FIG. 7 is a perspective view showing another third magnetic marker in Example 1. FIG. 実施例２における、マーカ棒の説明図。FIG. 7 is an explanatory diagram of a marker bar in Example 2. 実施例２における、マーカ棒から磁気マーカを切り出す様子の説明図。FIG. 7 is an explanatory diagram showing how a magnetic marker is cut out from a marker rod in Example 2. 実施例２における、マーカ棒の先端を収容孔に差し入れた状態の説明図。FIG. 7 is an explanatory diagram of the state in which the tip of the marker rod is inserted into the accommodation hole in Example 2. 実施例２における、マーカ棒の先端の磁気マーカを分離する手順その１の説明図。FIG. 7 is an explanatory diagram of the first procedure for separating the magnetic marker at the tip of the marker rod in Example 2. 実施例２における、マーカ棒の先端の磁気マーカを分離する手順その２の説明図。FIG. 7 is an explanatory diagram of the second procedure for separating the magnetic marker at the tip of the marker rod in Example 2. 実施例２における、マーカ棒の先端の磁気マーカを切り離して収容孔に配置する手順の説明図。FIG. 7 is an explanatory diagram of a procedure for separating the magnetic marker at the tip of the marker rod and placing it in the accommodation hole in Example 2.
（実施例１）
　本例は、車両に取り付けられた磁気センサ（図示略）で検出できるように道路３に配設され、運転者による車両の運転操作の支援、あるいは運転者の操作に依らない自動運転を実現するための車両側の制御を実現するための磁気マーカ１の例である。この内容について、図１～図９を参照して説明する。 (Example 1)
This example is installed on a road 3 so that it can be detected by a magnetic sensor (not shown) attached to the vehicle, and supports the driver's operation of the vehicle or realizes automatic driving that does not depend on the driver's operation. This is an example of a magnetic marker 1 for realizing control on the vehicle side. The contents will be explained with reference to FIGS. 1 to 9.
　本例の磁気マーカ１（図１）は、埋設型の磁気マーカであり、路面３Ｓに設けられた深さ３０ｍｍの収容孔３０に収容された状態で配設（埋設）される。磁気マーカ１は、直径３０ｍｍ、高さ２０ｍｍの柱状を呈する。収容孔の深さ３０ｍｍに対して、磁気マーカ１の高さが２０ｍｍであるので、収容孔３０に配置された磁気マーカ１の上面は、路面から１０ｍｍほど奥まった位置となる。収容孔３０には、磁気マーカ１を収容した後、アスファルトや樹脂材料等の高分子材料が充填される。これにより、磁気マーカ１の上面側には、アスファルトや樹脂材料等によりなる蓋３１が形成される。 The magnetic marker 1 (FIG. 1) of this example is a buried type magnetic marker, and is installed (buried) in a state of being accommodated in a 30 mm deep accommodation hole 30 provided in the road surface 3S. The magnetic marker 1 has a columnar shape with a diameter of 30 mm and a height of 20 mm. Since the height of the magnetic marker 1 is 20 mm with respect to the depth of the accommodation hole 30 mm, the upper surface of the magnetic marker 1 placed in the accommodation hole 30 is set back about 10 mm from the road surface. After accommodating the magnetic marker 1, the accommodating hole 30 is filled with a polymeric material such as asphalt or a resin material. As a result, a lid 31 made of asphalt, resin material, or the like is formed on the upper surface side of the magnetic marker 1.
　アスファルト等で舗装された道路３の断面構造（図示略）は、大まかに、土を押し固めた路床、砕石やクラッシャランなどの粒状材料による路盤、加熱アスファルト混合物よりなる表層、という三層構造を有する。加熱アスファルト混合物は、粗骨材３３１、細骨材３３２、フィラーおよびアスファルトが、加熱状態で混合されたアスファルト混合物である。表層の層厚は、例えば１０ｃｍ程度である。 The cross-sectional structure (not shown) of the road 3 paved with asphalt etc. roughly has a three-layer structure: a roadbed made of compacted soil, a roadbed made of granular materials such as crushed stone or crushed run, and a surface layer made of a heated asphalt mixture. have The heated asphalt mixture is an asphalt mixture in which coarse aggregate 331, fine aggregate 332, filler, and asphalt are mixed in a heated state. The thickness of the surface layer is, for example, about 10 cm.
　粗骨材３３１は、例えば、粒径２．５～５ｍｍの砕石である。細骨材３３２は、例えば、２．３６ｍｍのふるいを通過し、０．０７５ｍｍのふるいに留まる骨材である。細骨材３３２は、例えば、０．０７５～２．３６ｍｍの粒径の砂である。図示を省略するフィラーは、０．０７５ｍｍのふるいを通過する鉱物質粉末である。フィラーは、例えば、石灰岩を粉末にした石粉である。 The coarse aggregate 331 is, for example, crushed stone with a particle size of 2.5 to 5 mm. Fine aggregate 332 is, for example, aggregate that passes through a 2.36 mm sieve and remains on a 0.075 mm sieve. The fine aggregate 332 is, for example, sand with a particle size of 0.075 to 2.36 mm. The filler, which is not shown, is a mineral powder that passes through a 0.075 mm sieve. The filler is, for example, stone powder made from powdered limestone.
　道路３の舗装は、経年に応じて、ポットホールなどの傷みが不可避である。ポットホールは、加熱アスファルト混合物からなる表層の一部が路面３Ｓから剥離して起こる穴である。ポットホールは、例えば、表層をなす加熱アスファルト混合物中の粗骨材３３１同士の連結構造が損なわれて生じる。 The pavement of Road 3 inevitably suffers damage such as potholes as it ages. A pothole is a hole that occurs when a part of the surface layer made of the heated asphalt mixture peels off from the road surface 3S. Potholes occur, for example, when the connection structure between coarse aggregates 331 in the heated asphalt mixture forming the surface layer is damaged.
　磁気マーカ１（図１）は、直径３０ｍｍ、高さ２０ｍｍの柱状の永久磁石である。磁気マーカ１をなす磁石は、磁性材料である酸化鉄の磁粉を基材である高分子材料中に分散させた等方性フェライトプラスチックマグネットである。この磁石は、最大エネルギー積（ＢＨｍａｘ）＝１２ｋＪ／立方ｍという磁気的な特性を備えている。なお、磁石をなす高分子材料としては、例えば、アスファルト、ゴム、ＰＰＳ（Poly Phenylene Sulfide）、ナイロン６６、ナイロン１２等を例示できる。 The magnetic marker 1 (FIG. 1) is a columnar permanent magnet with a diameter of 30 mm and a height of 20 mm. The magnet forming the magnetic marker 1 is an isotropic ferrite plastic magnet in which iron oxide magnetic powder, which is a magnetic material, is dispersed in a polymeric material, which is a base material. This magnet has a magnetic property of maximum energy product (BHmax)=12 kJ/m3. Note that examples of polymeric materials forming the magnet include asphalt, rubber, PPS (Poly Phenylene Sulfide), nylon 66, and nylon 12.
　等方性フェライトプラスチックマグネットは、磁性材料が酸化鉄であるため腐食に強く、金属製のケース等に収容する必要がない。それ故、本例の磁気マーカ１は、磁石そのものであっても良い。必要に応じて磁石の外周面に適宜、コーティング層を設けても良い。磁気マーカ１は、路面３Ｓに設けた収容孔３０に直接、収容可能である。 Because the magnetic material of isotropic ferrite plastic magnets is iron oxide, they are resistant to corrosion and do not need to be housed in a metal case. Therefore, the magnetic marker 1 of this example may be a magnet itself. If necessary, a coating layer may be provided on the outer peripheral surface of the magnet. The magnetic marker 1 can be directly accommodated in the accommodation hole 30 provided in the road surface 3S.
　本例の磁気マーカ１は、表面の磁束密度が４５ｍＴ（ミリテスラ）であって、高さ２５０ｍｍに到達する磁束密度が８μＴ程度という磁気的な特性を有する。なお、高さ２５０ｍｍは、車両における磁気センサの取付高さの想定範囲のうちの上限に当たる高さの一例である。 The magnetic marker 1 of this example has magnetic properties such that the surface magnetic flux density is 45 mT (millitesla) and the magnetic flux density reaching a height of 250 mm is about 8 μT. Note that the height of 250 mm is an example of a height that corresponds to the upper limit of the expected range of mounting heights of the magnetic sensor in a vehicle.
　本例の磁気マーカ１は、外部から作用する力に応じた応力の均一性が損なわれて応力が集中する箇所が生じる形状の永久磁石である点に特徴を有する。外部から力が作用したときの応力が均一性高く生じる磁気マーカとの比較において、磁気マーカ１は、応力集中により破断し易く、複数の小片に分離し易くなっている。 The magnetic marker 1 of this example is characterized in that it is a permanent magnet with a shape in which the uniformity of stress in response to external forces is impaired, resulting in areas where stress is concentrated. In comparison with a magnetic marker that generates stress with high uniformity when an external force is applied, the magnetic marker 1 is more likely to break due to stress concentration and is more likely to separate into a plurality of small pieces.
　一般に、物体における応力集中は、断面積が急変する箇所で生じる傾向にある。外部から力が作用したときに応力が集中すれば、物体の構成材料の材料的な強度を超える過大な応力が発生し易くなる。当然ながら、断面積が急変する箇所がなく、外部から力が作用したときに均一性高く応力が発生し、応力の最大値が抑制される物体と比べて、応力が集中する箇所を有する物体は破断が生じ易い。 In general, stress concentration in an object tends to occur at locations where the cross-sectional area changes suddenly. If stress is concentrated when an external force is applied, excessive stress that exceeds the material strength of the constituent materials of the object is likely to occur. Naturally, compared to an object where there is no sudden change in cross-sectional area, stress is generated with high uniformity when an external force is applied, and the maximum value of stress is suppressed, an object with points where stress is concentrated is Breakage is likely to occur.
　仮に、路面３Ｓに露出した磁気マーカ１が一体のままであると、ポットホール等の発生に応じて磁気マーカ１が一体的に道路から脱落し、磁気マーカ１の磁気的な機能が一気に失われることになる。複数の小片に分離可能な構造を備える本例の磁気マーカ１であれば、ポットホール等の拡大に応じて一部を分離でき、残りの一部が道路側に残存できる可能性がある。そのため、磁気マーカ１は、その磁気的な機能をある程度、維持できる可能性が高い。 If the magnetic marker 1 exposed on the road surface 3S remains in one piece, the magnetic marker 1 will fall off the road as a whole due to the occurrence of potholes, and the magnetic function of the magnetic marker 1 will be lost all at once. It turns out. If the magnetic marker 1 of this example has a structure that can be separated into a plurality of small pieces, it is possible to separate a part according to the enlargement of a pothole or the like, and the remaining part may remain on the road side. Therefore, there is a high possibility that the magnetic marker 1 can maintain its magnetic function to some extent.
　このように本例の磁気マーカ１は、周囲に磁気を作用するという磁気マーカの機能が一気に失われるおそれが低減された優れた特性の磁気マーカである。本実施例では、このような特性を備える磁気マーカ１を複数種類、例示する。 As described above, the magnetic marker 1 of this example is a magnetic marker with excellent characteristics that reduces the risk of the magnetic marker losing its function of exerting magnetism on the surrounding area all at once. In this embodiment, a plurality of types of magnetic markers 1 having such characteristics are illustrated.
（第１の磁気マーカ）
　第１の磁気マーカ１は、図２及び図３に示す磁気マーカである。図２は、磁気マーカ１の外観を示す斜視図である。図３は、柱状の中心軸を含む断面の構造を示す断面図である。同図の断面は、図２中のＡ－Ａ線の断面である。第１の磁気マーカ１は、永久磁石である等方性フェライトプラスチックマグネットを柱状に成形した中間加工品（図示略）を作製した後、その外周面にスリット加工を施したものである。 (first magnetic marker)
The first magnetic marker 1 is the magnetic marker shown in FIGS. 2 and 3. FIG. 2 is a perspective view showing the appearance of the magnetic marker 1. FIG. 3 is a cross-sectional view showing the structure of a cross section including the central axis of the columnar shape. The cross section in this figure is taken along line AA in FIG. The first magnetic marker 1 is made by producing an intermediate product (not shown) in which an isotropic ferrite plastic magnet, which is a permanent magnet, is formed into a columnar shape, and then slitting the outer peripheral surface of the product.
　このスリット加工では、例えばレーザー加工によって、柱状の軸方向に直交する円環状のスリット１０１が複数、一定の間隔を空けて設けられる。溝の一例をなすスリット１０１の幅は、例えば０．１～０．２ｍｍという微細なものである。円環状のスリット１０１の内径は例えば５ｍｍである。この磁気マーカ１では、スリット１０１の存在により、軸方向に直交する断面積が軸方向において急変する箇所が生じ、この箇所が応力が集中する箇所になっている。 In this slit processing, for example, by laser processing, a plurality of annular slits 101 orthogonal to the axial direction of the column are provided at regular intervals. The width of the slit 101, which is an example of a groove, is as fine as, for example, 0.1 to 0.2 mm. The inner diameter of the annular slit 101 is, for example, 5 mm. In this magnetic marker 1, due to the presence of the slit 101, there is a location where the cross-sectional area perpendicular to the axial direction changes suddenly in the axial direction, and this location is a location where stress is concentrated.
　磁気マーカ１は、図３のごとく、円環状のスリット１０１により区画された磁石シートが複数、積層されたような構造を有している。この磁気マーカ１では、スリット１０１によって応力が集中する箇所が生じており、スリット１０１が契機となって亀裂が生じやすい。磁気マーカ１は、スリット１０１で生じた亀裂、すなわち隙間の拡大により破断し、複数の小片に分離し易くなっている。この磁気マーカ１は、スリット１０１の存在により破断し易くなっており、前記中間加工品との比較において、複数の小片に分離するために要する力が小さくなっている。 As shown in FIG. 3, the magnetic marker 1 has a structure in which a plurality of magnet sheets separated by annular slits 101 are stacked. In this magnetic marker 1, the slits 101 create areas where stress is concentrated, and cracks are likely to occur due to the slits 101. The magnetic marker 1 breaks due to the crack generated in the slit 101, that is, the gap widens, and is easily separated into a plurality of small pieces. This magnetic marker 1 is easily broken due to the presence of the slit 101, and the force required to separate it into a plurality of small pieces is smaller than that of the intermediate product.
　なお、スリット１０１（図３）の内部に、軟磁性材料の粉末等を充填することも良い。軟磁性材料としては、例えば、鉄、けい素鉄、パーマロイ等を例示できる。充填する軟磁性材料の態様は、磁気マーカ１をなす磁石よりも強度が低く、破断し易い態様であると良い。軟磁性材料に代えて、樹脂材料などの高分子材料を充填しても良い。軟磁性材料は、透磁率が高いため、スリット１０１を設けたことによる磁気的性能の低下を抑制できる。なお、本例のごとく、０．１～０．２ｍｍ程度の隙間であれば、磁気的性能の低下は大きな問題とはならない。隙間がより大きくなり、磁気的性能の低下が大きくなったような場合、スリット１０１に充填された軟磁性材料の有効性が顕著になる。スリット１０１が設けられた外周面に、樹脂材料によるコーティングを施すことも良い。 Incidentally, the inside of the slit 101 (FIG. 3) may be filled with soft magnetic material powder or the like. Examples of the soft magnetic material include iron, silicon iron, permalloy, and the like. It is preferable that the soft magnetic material to be filled has a lower strength than the magnet forming the magnetic marker 1 and is easily broken. Instead of the soft magnetic material, a polymeric material such as a resin material may be filled. Since the soft magnetic material has high magnetic permeability, deterioration in magnetic performance due to the provision of the slit 101 can be suppressed. Note that, as in this example, if the gap is about 0.1 to 0.2 mm, deterioration in magnetic performance will not be a major problem. When the gap becomes larger and the deterioration of magnetic performance becomes greater, the effectiveness of the soft magnetic material filled in the slit 101 becomes significant. It is also possible to coat the outer peripheral surface where the slit 101 is provided with a resin material.
　磁気マーカ１の外周面において開口するスリット１０１の開口部は、覆わなくても良い。この場合には、スリット１０１内に浸入した水分等の氷結により、スリット１０１を契機とした破断を促進できる。磁気マーカ１が予め破断していれば、ポットホールの拡大に応じて直ちに一部を分離できる可能性が高い。さらに、発泡樹脂等の多孔性の材料をスリット１０１に充填することも良い。この場合には、毛細管現象によってスリット１０１内に水分を吸い上げることで、水分の浸入を促進できる。 The opening of the slit 101 that opens on the outer peripheral surface of the magnetic marker 1 does not need to be covered. In this case, the freezing of moisture or the like that has entered the slit 101 can promote breakage triggered by the slit 101. If the magnetic marker 1 is broken in advance, there is a high possibility that a portion can be immediately separated as the pothole expands. Furthermore, it is also good to fill the slit 101 with a porous material such as foamed resin. In this case, the infiltration of moisture can be promoted by sucking up the moisture into the slit 101 by capillary action.
　なお、例えば、円板状をなすと共に、外周部よりも内周部が厚い図４の磁石シート１１を、軸方向に積層して相互に接合することで、図２及び図３と同様の磁気マーカ１を得ることも良い。あるいは、図示は省略するが、一定の厚さの円板と小径の円板とを交互に積層して接合すれば、図２及び図３の磁気マーカ１と同じ形状の磁気マーカを得ることができる。 For example, by laminating the magnetic sheets 11 shown in FIG. 4, which are disk-shaped and have a thicker inner circumference than the outer circumference, in the axial direction and bonding them to each other, a magnetic field similar to that shown in FIGS. 2 and 3 can be obtained. It is also good to get marker 1. Alternatively, although not shown, if disks of a certain thickness and disks of a small diameter are alternately stacked and joined, a magnetic marker having the same shape as the magnetic marker 1 in FIGS. 2 and 3 can be obtained. can.
　図４の磁石シート１１を接合するための接着材料あるいは粘着材料として、例えば、時間が経過しても硬化しない接着材料あるいは粘着材料を採用すれば、接合層を介して隣り合う磁石シート１１が分離し易くなる。あるいは硬化する一方、接合層の破断が生じやすい接着材料等を採用することも良い。接合層が破断すれば、隣り合う磁石シートの間で亀裂が生じて破断し、磁気マーカ１が複数の小片に分離し易くなる。 For example, if an adhesive material or adhesive material that does not harden over time is used as the adhesive material or adhesive material for joining the magnet sheets 11 in FIG. 4, adjacent magnet sheets 11 can be separated via the joining layer. It becomes easier to do. Alternatively, it is also possible to use an adhesive material that hardens but easily causes the bonding layer to break. If the bonding layer ruptures, cracks will occur between adjacent magnet sheets and the bonding layer will break, making it easy for the magnetic marker 1 to separate into a plurality of small pieces.
　なお、接着材料は、使用前は液体の状態にあって、経時変化により個体となる狭義の接着材料である。粘着材料は、液体と固体の両方の性質を有し、半固形で粘性を持つ粘着材料である。広義の接着材料の概念に、狭義の接着材料および粘着材料が含まれると考えることもできる。 Note that the adhesive material is an adhesive material in the narrow sense that is in a liquid state before use and becomes solid over time. The adhesive material is a semi-solid and viscous adhesive material that has both liquid and solid properties. It can also be considered that the concept of adhesive material in a broad sense includes adhesive materials and adhesive materials in a narrow sense.
　接着材料あるいは粘着材料としては、例えば、接合直後には比較的強度が高い一方、経時変化等により、接合強度が次第に低下する接着材料等を採用することも良い。また、例えば、何らかの解体因子を有し、解体因子を活性化させる解体操作により接合力が低下したり剥離したりする特性を有する解体性接着材料あるいは解体性粘着材料を採用することも良い。 As the adhesive material or adhesive material, for example, it is also possible to use an adhesive material that has relatively high strength immediately after bonding, but whose bonding strength gradually decreases due to changes over time. Further, for example, it is also possible to employ a disassembly adhesive material or a disassembly adhesive material that has some kind of disassembly factor and has the property that the bonding force decreases or the adhesive material peels off due to a disassembly operation that activates the disassembly factor.
　例えば、粘着界面でのガス発生という解体因子を備えており、紫外線照射という解体操作により接合力を喪失する粘着材料であっても良い。この粘着材料は、例えば、紫外線剥離テープの粘着材料として利用される。紫外線剥離テープは、半導体プロセスにおいてダイシングテープと呼ばれるテープである。例えば、吸水性樹脂の膨張という解体因子を備え、水浸漬といった解体操作により接合力が低下する吸水性樹脂混入接着材料であっても良い。例えば、マイクロカプセルの膨張という解体因子を備え、加熱によって接合力が低下する熱膨張性マイクロカプセル混入粘着材料であっても良い。例えば、軟化・溶融という解体因子を備えており、加熱という解体操作によって接合力が低下する熱硬化・熱可塑性接着材料であっても良い。例えば、粘着材料の脆性化という解体因子を備えており、加熱、紫外性照射によって脆性化し接合力が低下する粘着材料であっても良い。例えば、加水分解という解体因子を備えており、水分の供給という解体操作により接合力が低下する加水分解性の接着材料あるいは粘着材料であっても良い。接着材料の吸湿及び軟化・溶融という解体因子を備えており、温水浸漬によって接合力が低下する吸湿剥離接着材料であっても良い。例えば、軟化・溶融という解体因子を備えており、電磁誘導加熱によって接合力が低下する電磁誘導・熱可塑性接着材料であっても良い。例えば、力学的破壊という解体因子を備えており、垂直負荷を作用するという解体操作により接合力が低下する易剥離接着材料であっても良い。例えば、力学的破壊という解体因子を備えており、せん断負荷の作用という解体操作により接合力が低下する粘着材料であっても良い。 For example, it may be an adhesive material that has a disassembly factor such as gas generation at the adhesive interface and loses its bonding strength by the disassembly operation of ultraviolet irradiation. This adhesive material is used, for example, as an adhesive material for ultraviolet release tape. Ultraviolet release tape is a tape called dicing tape in semiconductor processes. For example, it may be a water-absorbing resin-containing adhesive material that has a disassembly factor such as expansion of the water-absorbing resin and whose bonding strength is reduced by a disassembly operation such as immersion in water. For example, it may be a thermally expandable microcapsule-containing adhesive material that has a disintegration factor of microcapsule expansion and whose bonding strength is reduced by heating. For example, it may be a thermosetting/thermoplastic adhesive material that has disassembly factors such as softening and melting, and whose bonding strength is reduced by the disassembly operation of heating. For example, it may be an adhesive material that has a disassembly factor of embrittlement of the adhesive material and whose bonding strength decreases due to the embrittlement caused by heating or ultraviolet irradiation. For example, it may be a hydrolyzable adhesive material or adhesive material that has a disassembly factor called hydrolysis and whose bonding strength is reduced by the disassembly operation of supplying moisture. It may be a moisture-absorbing and peelable adhesive material that has disintegration factors such as moisture absorption and softening/melting of the adhesive material, and whose bonding strength decreases when immersed in hot water. For example, it may be an electromagnetic induction/thermoplastic adhesive material that has disintegration factors such as softening and melting, and whose bonding strength is reduced by electromagnetic induction heating. For example, it may be an easily peelable adhesive material that has a disassembly factor of mechanical fracture and whose bonding strength is reduced by a disassembly operation of applying a vertical load. For example, it may be an adhesive material that has a disassembly factor called mechanical destruction and whose bonding strength decreases due to the disassembly operation called action of shear load.
　また、例えば、生分解性の接着材料あるいは粘着材料を採用することも良い。自然界の中で分解する生分解性の接着材料等を利用すれば、磁気マーカ１の埋設後に接合力を次第に低下させることができる。さらに、生分解性の接着材料等であれば、磁気マーカ１の廃棄が容易になり、磁気マーカ１の廃棄に要するコストを低減できる。 Furthermore, for example, it is also possible to use a biodegradable adhesive material or adhesive material. By using a biodegradable adhesive material that decomposes in nature, the bonding force can be gradually reduced after the magnetic marker 1 is embedded. Furthermore, if the adhesive material is biodegradable, the magnetic marker 1 can be easily disposed of, and the cost required for disposing of the magnetic marker 1 can be reduced.
　収容孔３０（図１参照。）に磁気マーカ１を収容した後、アスファルト等や樹脂材料等の高分子材料を収容孔３０に充填すれば、その高分子材料によって磁気マーカ１の形状が保持され得る。そのため、経時的に接合層の接合力が失われても、収容孔３０に磁気マーカ１が留まる限り、磁気マーカ１が複数の小片に分離することなく、一体の状態が保持され得る。 After accommodating the magnetic marker 1 in the accommodating hole 30 (see FIG. 1), if the accommodating hole 30 is filled with a polymeric material such as asphalt or a resin material, the shape of the magnetic marker 1 is maintained by the polymeric material. obtain. Therefore, even if the bonding force of the bonding layer is lost over time, as long as the magnetic marker 1 remains in the accommodation hole 30, the magnetic marker 1 will not separate into a plurality of small pieces and will remain in an integrated state.
（第２の磁気マーカ）
　第２の磁気マーカ１は、図５及び図６に示す磁気マーカである。図５は、磁気マーカ１の外観を示す斜視図である。図６は、磁気マーカ１の軸方向に直交する断面図である。同図の断面は、図５におけるＢ－Ｂ線による輪切りの断面である。この磁気マーカ１では、中心軸と交差する径方向の横孔１０２（孔の一例。）が複数、穿設されている。この磁気マーカ１は、例えば、柱状の中間加工品を作製した後、径方向に貫通する横孔１０２を多数、設けた磁性部品である。 (Second magnetic marker)
The second magnetic marker 1 is the magnetic marker shown in FIGS. 5 and 6. FIG. 5 is a perspective view showing the appearance of the magnetic marker 1. FIG. 6 is a cross-sectional view of the magnetic marker 1 perpendicular to the axial direction. The cross section in this figure is a cross section taken along line BB in FIG. In this magnetic marker 1, a plurality of horizontal holes 102 (an example of a hole) are bored in the radial direction intersecting the central axis. The magnetic marker 1 is, for example, a magnetic component in which a columnar intermediate product is manufactured and then provided with a large number of lateral holes 102 passing through it in the radial direction.
　横孔１０２は、例えばレーザー加工による直径０．５～１．０ｍｍ程度の微細な孔である。横孔１０２は、円柱状の磁気マーカ１の中心軸と交差し、径方向に貫通している。横孔１０２は、磁気マーカ１の軸方向における２ｍｍおきの９か所の断面（以下、横孔１０２の形成面という。）に沿っている。両端の形成面は、それぞれ、磁気マーカ１の端面から軸方向に１ｍｍ離れて位置している。磁気マーカ１における各形成面では、例えば周方向、１６分割の等間隔（角度２２．５度の等間隔）で複数の横孔１０２が穿設されている（図６参照。）。 The horizontal hole 102 is a fine hole with a diameter of about 0.5 to 1.0 mm formed by laser processing, for example. The horizontal hole 102 intersects with the central axis of the cylindrical magnetic marker 1 and penetrates in the radial direction. The horizontal holes 102 are along nine cross sections (hereinafter referred to as the formation surfaces of the horizontal holes 102) at 2 mm intervals in the axial direction of the magnetic marker 1. The forming surfaces at both ends are each located 1 mm away from the end surface of the magnetic marker 1 in the axial direction. In each formation surface of the magnetic marker 1, a plurality of horizontal holes 102 are bored, for example, at equal intervals of 16 divisions (equal intervals of 22.5 degrees) in the circumferential direction (see FIG. 6).
　なお、形成面は、９か所よりも多い箇所であっても良く、少なくても良い。形成面は、不等間隔であっても良い。また、形成面における横孔１０２の周方向の間隔についても、１６分割よりも細かくても良く、粗くても良い。横孔１０２の周方向の間隔は不等間隔であっても良い。 Note that the number of formation surfaces may be greater than or equal to nine locations. The formation surfaces may be irregularly spaced. Further, the circumferential interval of the horizontal holes 102 on the forming surface may be finer or coarser than 16 divisions. The circumferential intervals of the horizontal holes 102 may be irregular.
　図５及び図６の磁気マーカ１は、隙間の一例をなす横孔１０２の形成面において亀裂が生じ易く、複数の小片に分離可能な構造を有する。この磁気マーカ１は、横孔１０２の形成面を介して磁石シートが積層されたごとき磁気マーカである。この磁気マーカ１では、横孔１０２の形成面の存在により強度が低下している。磁気マーカ１は、隙間である横孔１０２の拡大により形成面を介して隣り合う小片が分離する。この磁気マーカ１は、横孔１０２が設けられた形成面の存在により、上記の中間加工品よりも破断し易く小片に分離し易くなっている。図５及び図６の磁気マーカ１では、軸方向における前記形成面のところで、軸方向に直交する断面積が急激に減少しており、応力が集中する箇所が生じている。 The magnetic marker 1 shown in FIGS. 5 and 6 has a structure in which cracks are likely to occur on the surface where the horizontal hole 102, which is an example of a gap, is formed, and can be separated into a plurality of small pieces. This magnetic marker 1 is a magnetic marker in which magnetic sheets are laminated through the surface in which the horizontal hole 102 is formed. In this magnetic marker 1, the strength is reduced due to the presence of the surface on which the horizontal hole 102 is formed. In the magnetic marker 1, adjacent small pieces are separated via the forming surface due to the enlargement of the horizontal hole 102, which is a gap. Due to the presence of the forming surface provided with the horizontal holes 102, this magnetic marker 1 is more easily broken and separated into small pieces than the above-mentioned intermediate product. In the magnetic marker 1 shown in FIGS. 5 and 6, the cross-sectional area perpendicular to the axial direction rapidly decreases at the formation surface in the axial direction, resulting in areas where stress is concentrated.
　なお、横孔１０２の内部に、軟磁性材料を充填することも良い。軟磁性材料の態様は、磁気マーカ１をなす磁石よりも強度が低く、破断し易い態様であると良い。軟磁性材料に代えて、樹脂材料などの高分子材料を充填しても良い。横孔１０２が開口する外周面に、樹脂材料によるコーティングを設けることも良い。 Note that the inside of the horizontal hole 102 may also be filled with a soft magnetic material. It is preferable that the soft magnetic material has a lower strength than the magnet forming the magnetic marker 1 and is easily broken. Instead of the soft magnetic material, a polymeric material such as a resin material may be filled. It is also good to provide a coating with a resin material on the outer peripheral surface where the horizontal hole 102 opens.
　なお、図７に示すように、横孔１０２に代えて、軸方向に貫通する縦孔１０３（孔の一例。）を設けることも良い。例えば、縦孔１０３は、磁気マーカ１の中心軸を含む平面に沿って複数、形成されている。磁気マーカ１では、このように縦孔１０３が沿う平面が、周方向における４５度の等間隔で設けられている。磁気マーカ１の端面では、縦孔１０３の開口が放射状に配置されている。同図の磁気マーカ１では、隙間の一例をなす縦孔１０３の形成面（上記の平面。）により区画された断面扇形状の柱状領域が形成されている。図７の磁気マーカ１では、周方向における前記縦孔１０３が形成された平面のところで、中心軸を含む平面の断面積が急激に減少する箇所が生じており、これにより応力が集中する箇所が生じている。 Note that, as shown in FIG. 7, instead of the horizontal hole 102, a vertical hole 103 (an example of a hole) that penetrates in the axial direction may be provided. For example, a plurality of vertical holes 103 are formed along a plane including the central axis of the magnetic marker 1. In the magnetic marker 1, the planes along which the vertical holes 103 lie are arranged at equal intervals of 45 degrees in the circumferential direction. On the end surface of the magnetic marker 1, openings of the vertical holes 103 are arranged radially. In the magnetic marker 1 shown in the figure, a columnar region with a fan-shaped cross section is formed, which is partitioned by the surface (the above-mentioned plane) in which the vertical hole 103 is formed, which is an example of a gap. In the magnetic marker 1 shown in FIG. 7, there is a point where the cross-sectional area of the plane including the central axis sharply decreases at the plane where the vertical hole 103 is formed in the circumferential direction, and this causes a point where stress is concentrated. It is occurring.
　なお、横孔１０２（図５及び図６）に加えて縦孔１０３（図７）を設けることも良い。本例では、横孔１０２及び縦孔１０３として、貫通孔を例示しているが、貫通していない有底の孔であっても良い。隙間の一例をなす孔を設けた磁気マーカは、孔の存在により強度が低下しており破断し易くなっている。この磁気マーカは、破断によって複数の小片に分離可能な構造を有する。
　なお、横孔１０２及び縦孔１０３の開口部分の取り扱いについては、スリット１０１の場合と同様である。外部に開口したままとしても良い。 Note that in addition to the horizontal hole 102 (FIGS. 5 and 6), a vertical hole 103 (FIG. 7) may also be provided. In this example, through holes are illustrated as the horizontal holes 102 and the vertical holes 103, but they may be holes with bottoms that do not penetrate through them. A magnetic marker provided with a hole, which is an example of a gap, has a reduced strength due to the presence of the hole and is easily broken. This magnetic marker has a structure that can be separated into a plurality of small pieces by breaking.
Note that handling of the opening portions of the horizontal hole 102 and the vertical hole 103 is the same as in the case of the slit 101. It may be left open to the outside.
（第３の磁気マーカ）
　図８の磁気マーカ１は、断面扇形状の柱状の複数の磁石領域１３に区分されるよう、径方向のスリット１３１を設けた磁気マーカである。スリット１３１は、径方向及び軸方向により規定される平面に沿うように形成され、径方向における磁気マーカ１の中心部１Ｃを避けて形成されている。それ故、断面扇形状の複数の磁石領域１３は、パイナップルの芯のような中心部１Ｃを介して相互に連結されている。 (Third magnetic marker)
The magnetic marker 1 in FIG. 8 is a magnetic marker provided with a radial slit 131 so as to be divided into a plurality of columnar magnet regions 13 having a sector-shaped cross section. The slit 131 is formed along a plane defined by the radial direction and the axial direction, avoiding the center portion 1C of the magnetic marker 1 in the radial direction. Therefore, the plurality of magnet regions 13 having a sector-shaped cross section are interconnected through the central portion 1C, which resembles the core of a pineapple.
　この磁気マーカ１では、断面扇形状の磁石領域１３が中心部１Ｃに接続されているのみであり、周方向において隣り合う磁石領域１３はスリット１３１を介して隣り合っており、相互に接続されていない。すなわち、図８の磁気マーカ１では、スリット１３１の存在により、中心軸を含む径方向の断面積が周方向において急変する箇所があり、この箇所において応力が集中する。 In this magnetic marker 1, the magnet region 13 having a sector-shaped cross section is only connected to the center portion 1C, and the magnet regions 13 that are adjacent to each other in the circumferential direction are adjacent to each other via the slit 131 and are not connected to each other. do not have. That is, in the magnetic marker 1 of FIG. 8, due to the presence of the slit 131, there is a portion where the radial cross-sectional area including the central axis changes suddenly in the circumferential direction, and stress is concentrated at this portion.
　なお、前記の磁気マーカの中心部１Ｃに相当する磁石棒を用意し、磁石棒に対して磁石領域１３をなす磁石片を接合して、図８の磁気マーカ１と同様の磁気マーカを形成することも良い。
　スリット１３１には、軟磁性材料を充填することも良い。軟磁性材料の態様は、磁気マーカ１をなす磁石よりも強度が低く、破断し易い態様であると良い。軟磁性材料に代えて、樹脂材料などの高分子材料を充填しても良い。スリット１３１が開口する外周面に、樹脂材料によるコーティングを設けることも良い。 A magnetic bar corresponding to the center portion 1C of the magnetic marker described above is prepared, and a magnet piece forming the magnet area 13 is joined to the magnetic bar to form a magnetic marker similar to the magnetic marker 1 in FIG. That's good too.
The slit 131 may also be filled with a soft magnetic material. It is preferable that the soft magnetic material has a lower strength than the magnet forming the magnetic marker 1 and is easily broken. Instead of the soft magnetic material, a polymeric material such as a resin material may be filled. It is also good to provide a coating with a resin material on the outer peripheral surface where the slit 131 opens.
　さらに、図９のごとく、図８の磁石領域１３と同様の形状の領域を複数のスリット１３２により輪切りし、複数の磁石領域１３５に分割することも良い。柱状の磁気マーカ１全体では、スリット１３２が中心部１Ｃを残して円環状をなしている。ピザの一片のような扇形状をなす磁石領域１３５は、中心部１Ｃに連結して保持されている。 Furthermore, as shown in FIG. 9, a region having the same shape as the magnet region 13 in FIG. In the entire columnar magnetic marker 1, the slit 132 has an annular shape except for the center portion 1C. A fan-shaped magnet region 135 like a piece of pizza is connected to and held at the center portion 1C.
　以上のように、本例の磁気マーカ１は、外部から作用する力に応じた応力の均一性が損なわれて応力が集中する箇所が生じる形状を有する柱状の永久磁石である。この磁気マーカ１では、施工対象の舗装をなす舗装材料よりも低脆性となるように応力が集中する箇所が設けられている。 As described above, the magnetic marker 1 of this example is a columnar permanent magnet that has a shape in which the uniformity of stress in response to external forces is impaired, resulting in areas where stress is concentrated. This magnetic marker 1 is provided with locations where stress is concentrated so that it is less brittle than the pavement material that makes up the pavement to be constructed.
　このような磁気マーカ１であれば、舗装が傷んでポットホールが生じたとき、ポットホールの拡がりに応じて応力集中が生じて破断し易く、一部を分離できる可能性がある。それ故、ポットホールが近くで生じた場合であっても、磁気マーカ１の一部が道路側に残存できる可能性が高くなっており、磁気マーカ１の磁気的な機能をある程度、維持できる可能性がある。 With such a magnetic marker 1, when the pavement is damaged and a pothole is generated, stress concentration occurs as the pothole spreads and it is likely to break, making it possible to separate a portion. Therefore, even if a pothole occurs nearby, there is a high possibility that a part of the magnetic marker 1 will remain on the road side, and it is possible to maintain the magnetic function of the magnetic marker 1 to some extent. There is sex.
　また、舗装の表層をなす粗骨材３３１が、例えば、粒径２．５～５ｍｍである一方、磁気マーカ１の大きさは直径３０ｍｍ高さ２０ｍｍである。仮に磁気マーカが一体的であると、ポットホールが生じたとき、粗骨材３３１よりも大きなサイズの磁気マーカが路面に転がり出る可能性がある。一方、複数の小片に分離可能な構造を有する本例の磁気マーカ１であれば、一体のままで路面に転がり出るおそれが少ない。この磁気マーカ１は、複数の小片に分離可能であるため、粗骨材３３１とサイズ的に同等、あるいはサイズ的により小さな小片となって路面に転がり出るのみである。 Further, the coarse aggregate 331 forming the surface layer of the pavement has a particle size of, for example, 2.5 to 5 mm, while the magnetic marker 1 has a diameter of 30 mm and a height of 20 mm. If the magnetic marker is integral, there is a possibility that when a pothole occurs, the magnetic marker larger than the coarse aggregate 331 may roll out onto the road surface. On the other hand, if the magnetic marker 1 of this example has a structure that can be separated into a plurality of small pieces, there is little risk of it rolling out onto the road surface while remaining as one piece. Since this magnetic marker 1 can be separated into a plurality of small pieces, it only rolls out onto the road surface as small pieces that are the same size or smaller than the coarse aggregate 331.
　本例では、断面円形状の柱状の磁気マーカを例示している。断面形状は、円形状に限定されない。三角形状、四角形状、五角形状等の断面形状を有する柱状の磁気マーカであっても良い。 In this example, a columnar magnetic marker with a circular cross section is illustrated. The cross-sectional shape is not limited to a circular shape. A columnar magnetic marker having a cross-sectional shape such as a triangular, square, or pentagonal shape may be used.
（実施例２）
　本例は、複数の小片に分離可能な構造を活用し、複数の磁気マーカを一体的に取り扱い可能とした態様の例である。本例は、実施例１の磁気マーカ１が複数、連結されたマーカ棒１Ｒに関する。この内容について、図１０～図１２（ｄ）を用いて説明する。 (Example 2)
This example is an example of an embodiment in which a plurality of magnetic markers can be handled integrally by utilizing a structure that can be separated into a plurality of small pieces. This example relates to a marker rod 1R in which a plurality of magnetic markers 1 of Example 1 are connected. This content will be explained using FIGS. 10 to 12(d).
　マーカ棒１Ｒ（図１０）は、２つの磁気マーカ１を軸方向に連結する連結面１００Ｃを有し、全体として、複数の磁気マーカ１により構成されている。連結面１００Ｃにおける２つの磁気マーカ１の連結強度は、個々の磁気マーカ１を小片に分離するのに要する強度よりもさらに小さく設定されている。 The marker rod 1R (FIG. 10) has a connecting surface 100C that connects two magnetic markers 1 in the axial direction, and is composed of a plurality of magnetic markers 1 as a whole. The connection strength between the two magnetic markers 1 on the connection surface 100C is set to be smaller than the strength required to separate each magnetic marker 1 into small pieces.
　例えば図１１に示すごとく、縁から先端が突き出すようにマーカ棒１Ｒを作業台１０５に載置し、その先端に直交方向の力を作用すれば、連結面１００Ｃが切断面となってマーカ棒１Ｒから磁気マーカ１を切り出しできる。作業台１０５の縁からの先端の突き出し量を、磁気マーカ１の高さ（全長）を若干超える程度に設定しておけば、磁気マーカ１を１個ずつ効率的に切り出しできる。 For example, as shown in FIG. 11, if the marker rod 1R is placed on the workbench 105 so that the tip protrudes from the edge and a force in the orthogonal direction is applied to the tip, the connecting surface 100C becomes a cutting surface and the marker rod 1R The magnetic marker 1 can be cut out from. If the amount of protrusion of the tip from the edge of the worktable 105 is set to slightly exceed the height (total length) of the magnetic marker 1, the magnetic markers 1 can be efficiently cut out one by one.
　マーカ棒１Ｒを利用し、例えば図１２（ａ）～（ｄ）に示すごとく、収容孔３０に磁気マーカ１を１個ずつ収容することも良い。直径３８ｍｍ深さ３０ｍｍの収容孔３０に、マーカ棒１Ｒの先端を例えば１３～１８ｍｍ程度（磁気マーカ１の高さ寸法以下。）、差し入れた状態で（図１２（ａ））、マーカ棒１Ｒの後端側を回動させれば（図１２（ｂ））、１個の磁気マーカ１を容易に分離できる（図１２（ｃ））。このようにしてマーカ棒１Ｒから分離された磁気マーカ１は、自重により収容孔３０の底に落下して収容される（図１２（ｄ））。 It is also possible to use the marker rod 1R to accommodate the magnetic markers 1 one by one in the accommodation holes 30, for example, as shown in FIGS. 12(a) to 12(d). When the tip of the marker rod 1R is inserted, for example, about 13 to 18 mm (less than the height of the magnetic marker 1) into the accommodation hole 30 with a diameter of 38 mm and a depth of 30 mm (Fig. 12(a)), the marker rod 1R is By rotating the rear end side (FIG. 12(b)), one magnetic marker 1 can be easily separated (FIG. 12(c)). The magnetic marker 1 separated from the marker rod 1R in this manner falls to the bottom of the accommodation hole 30 due to its own weight and is accommodated (FIG. 12(d)).
　例えば、実施例１の第２の磁気マーカ１であれば、横孔（図５中の符号１０２）と同様の横孔を連結面１００Ｃに穿設すると良い。この磁気マーカ１における横孔が周方向１６分割で形成されているのに対して、連結面１００Ｃでは、周方向３２分割等、より多い分割数で横孔を形成すると良い。この場合には、磁気マーカ１における横孔の形成面よりも連結面１００Ｃの強度を小さくできる。 For example, in the case of the second magnetic marker 1 of Example 1, a horizontal hole similar to the horizontal hole (numeral 102 in FIG. 5) may be bored in the connecting surface 100C. While the horizontal hole in this magnetic marker 1 is formed into 16 divisions in the circumferential direction, it is preferable to form the horizontal hole in a larger number of divisions, such as 32 divisions in the circumferential direction, on the connecting surface 100C. In this case, the strength of the connecting surface 100C can be made smaller than the surface of the magnetic marker 1 on which the horizontal holes are formed.
　なお、連結面１００Ｃの強度を抑制することは、必須の構成ではない。マーカ棒１Ｒから磁気マーカ１を１個ずつ切り出すための治具等を利用すると良い。治具等を利用すれば、軸方向における破断強度が略一定であるマーカ棒１Ｒから効率良く磁気マーカ１を切り出しできる。
　なお、他の構成及び作用効果については実施例１と同様である。 Note that it is not an essential configuration to suppress the strength of the connecting surface 100C. It is preferable to use a jig or the like to cut out the magnetic markers 1 one by one from the marker rod 1R. By using a jig or the like, the magnetic marker 1 can be efficiently cut out from the marker rod 1R whose breaking strength in the axial direction is substantially constant.
Note that the other configurations and effects are the same as in the first embodiment.
　以上、実施例のごとく本発明の具体例を詳細に説明したが、これらの具体例は、特許請求の範囲に包含される技術の一例を開示しているにすぎない。言うまでもなく、具体例の構成や数値等によって、特許請求の範囲が限定的に解釈されるべきではない。特許請求の範囲は、公知技術や当業者の知識等を利用して前記具体例を多様に変形、変更あるいは適宜組み合わせた技術を包含している。 Although specific examples of the present invention have been described above in detail as in the embodiments, these specific examples merely disclose an example of technology included in the scope of the claims. Needless to say, the scope of the claims should not be interpreted to be limited by the configurations, numerical values, etc. of the specific examples. The scope of the claims includes techniques in which the specific examples described above are variously modified, changed, or appropriately combined using known techniques and the knowledge of those skilled in the art.
　１　磁気マーカ
　１Ｒ　マーカ棒
　１００Ｃ　連結面
　１０１　スリット（溝、隙間）
　１０２　横孔（孔、隙間）
　１０３　縦孔（孔、隙間）
　１１　磁石シート
　１３、１３５　磁石領域
　１３１、１３２　スリット（溝）
　３　道路
　３Ｓ　路面
　３０　収容孔
　３３１　粗骨材
　３３２　細骨材 1 Magnetic marker 1R Marker rod 100C Connecting surface 101 Slit (groove, gap)
102 Horizontal hole (hole, gap)
103 Vertical hole (hole, gap)
11 Magnet sheet 13, 135 Magnet area 131, 132 Slit (groove)
3 Road 3S Road surface 30 Accommodation hole 331 Coarse aggregate 332 Fine aggregate

Claims (9)

  1. 　車両の運転支援に利用するために道路に配設される磁気マーカであって、
    　該磁気マーカは、外部から作用する力に応じた応力の均一性が損なわれて応力が集中する箇所が生じる形状を有する柱状の磁石である磁気マーカ。     A magnetic marker placed on a road for use in vehicle driving support,
    The magnetic marker is a columnar magnet having a shape where the uniformity of stress in response to an external force is impaired, resulting in areas where stress is concentrated.
  2. 　請求項１において、前記応力が集中する箇所は、前記柱状の磁石の外表面にスリット状の溝あるいは孔を穿設することにより設けられる磁気マーカ。 2. The magnetic marker according to claim 1, wherein the stress concentration area is provided by forming a slit-like groove or hole on the outer surface of the columnar magnet.
  3. 　請求項２において、前記溝あるいは孔は、前記柱状の磁石の軸方向に直交する断面に沿って形成され、前記応力が集中する箇所は、前記溝あるいは孔によって前記軸方向に直交する断面の面積が減少する箇所に形成されている磁気マーカ。 In claim 2, the groove or hole is formed along a cross section perpendicular to the axial direction of the columnar magnet, and the stress concentration area is an area of the cross section perpendicular to the axial direction due to the groove or hole. A magnetic marker is formed at a location where the amount of energy decreases.
  4. 　請求項３において、前記溝は、中心を取り囲む環状をなしており、前記軸方向に沿って複数、並列して設けられている磁気マーカ。 4. The magnetic marker according to claim 3, wherein the groove has an annular shape surrounding the center, and a plurality of grooves are provided in parallel along the axial direction.
  5. 　請求項２～４のいずれか１項において、前記溝あるいは孔は、前記柱状の磁石の軸方向に沿う断面に沿って形成され、前記応力が集中する箇所は、前記溝あるいは孔によって前記軸方向に沿う断面の面積が減少する箇所に形成されている磁気マーカ。 In any one of claims 2 to 4, the groove or hole is formed along a cross section along the axial direction of the columnar magnet, and the location where the stress is concentrated is defined by the groove or hole in the axial direction. A magnetic marker formed at a location where the area of the cross section along the line decreases.
  6. 　請求項５において、前記断面は、前記柱状の磁石の中心軸を含む面であって、当該断面が、前記中心軸で交差するように周方向に複数、設けられており、各断面に形成された溝によって前記柱状の磁石が分割されないよう、前記溝が前記中心軸を含む中心部を避けて形成されている磁気マーカ。 In claim 5, the cross section is a plane including the central axis of the columnar magnet, and a plurality of cross sections are provided in the circumferential direction so as to intersect at the central axis, and each cross section is formed. In order to prevent the columnar magnet from being divided by the groove, the groove is formed so as to avoid a central portion including the central axis.
  7. 　請求項１～６のいずれか１項において、前記応力が集中する箇所は、前記柱状の磁石の外表面に、切り欠き、溝、有底の孔、及び貫通孔、のうちの少なくともいずれかを穿設することにより設けられる磁気マーカ。 In any one of claims 1 to 6, the stress concentration area is formed by forming at least one of a notch, a groove, a hole with a bottom, and a through hole on the outer surface of the columnar magnet. A magnetic marker provided by drilling.
  8. 　請求項１～７のいずれか１項において、前記磁気マーカは、道路の舗装に埋設されるものであり、施工対象の舗装をなす舗装材料よりも低脆性となるように前記応力が集中する箇所が設けられている磁気マーカ。 According to any one of claims 1 to 7, the magnetic marker is embedded in the pavement of a road, and is located at a location where the stress is concentrated so as to have lower brittleness than the pavement material forming the pavement to be constructed. A magnetic marker with a
  9. 　請求項１～８のいずれか１項において、前記柱状の磁石は、高分子材料よりなる基材中に酸化鉄の磁性粉が分散された永久磁石である磁気マーカ。 The magnetic marker according to any one of claims 1 to 8, wherein the columnar magnet is a permanent magnet in which iron oxide magnetic powder is dispersed in a base material made of a polymeric material.
PCT/JP2023/011655 2022-03-25 2023-03-23 Magnetic marker WO2023182463A1 (en)

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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021106878A1 (en) * 2019-11-26 2021-06-03 愛知製鋼株式会社 Magnetic marker
JP2021095841A (en) * 2016-06-17 2021-06-24 愛知製鋼株式会社 Marker system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2021095841A (en) * 2016-06-17 2021-06-24 愛知製鋼株式会社 Marker system
WO2021106878A1 (en) * 2019-11-26 2021-06-03 愛知製鋼株式会社 Magnetic marker

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