JP2020159115A - On-road laid object - Google Patents

Abstract

To provide an on-road laid object that is excellent in durability and can be used advantageously for sensing using a magnetic sensor.SOLUTION: An on-road laid object laid on a road, comprises: a magnetic marker containing a magnetic material; and a cover layer covering at least a part of the magnetic marker. Here, it is preferable that the on-road laid object is provided with a plurality of magnetic markers, and one cover layer covers the plurality of magnetic markers. The magnetic material is preferably a ferrite magnet.SELECTED DRAWING: Figure 1

Description

The present invention relates to a road laying material, and more particularly to a road laying material that can be advantageously utilized when performing sensing using a magnetic sensor in an automatic driving system or a driving support system.

In recent years, a driving support system that assists a driver's driving operation of an automobile and an automatic driving system that automatically drives an automobile without the driver performing the driving operation have been attracting attention.

As a technology for identifying the current position of a vehicle in an automatic driving system or a driving support system, a magnetic marker system that measures the current position by detecting a magnetic marker provided on the road surface with a magnetic sensor installed at the bottom of the vehicle or the like. , It is known as a technology that can be advantageously used even in places where GPS is difficult to use, such as in a tunnel, or in bad weather such as rainfall, snowfall, and fog generation (see, for example, Patent Documents 1 and 2).

International Publication No. 2017/069089 International Publication No. 2017/069091

However, in the conventional magnetic marker system in which the magnetic marker is directly installed on the road surface, the magnetic marker is repeatedly stressed when a traveling vehicle passes over the magnetic marker, so that the magnetic marker deteriorates at an early stage. There was a problem.

Therefore, an object of the present invention is to provide a road laying material which is excellent in durability and can be advantageously used for sensing using a magnetic sensor.

An object of the present invention is to solve the above problems advantageously, and according to the present invention, the following road laying structures <1> to <17> are provided.
<1> Road laying objects laid on the road
A road laying structure comprising a magnetic marker containing a magnetic material and a cover layer covering at least a part of the magnetic marker.
<2> In the magnetic marker, the thickness t and Young's modulus E at a temperature of 60 ° C. have the following relational expression (1):
E / t ≧ 3 × 10 ⁹ [Pa / m] ・ ・ ・ (1)
The road construction according to <1> above, which satisfies the above conditions.
<3> In the magnetic marker, the thickness t and Young's modulus E at a temperature of 60 ° C. have the following relational expression (2):
E × t ≦ 4 × 10 ⁶ [Pa ・ m] ・ ・ ・ (2)
The road construction according to <1> or <2> above, which satisfies the above conditions.
<4> The road laying object according to any one of <1> to <3> above, wherein the magnetic marker is chamfered on the cover layer side at the end.
<5> The above-mentioned <1> to <4>, wherein the edge of the cover layer is located on the edge of the magnetic marker or inside the edge of the magnetic marker in a plan view. Road laying.
<6> The Young's modulus of the cover layer is larger than the Young's modulus of the magnetic marker.
The road laying object according to any one of <1> to <5> above, wherein the magnetic marker has a thin portion having a thin thickness.
<7> The road laying object according to any one of <1> to <6> above, which has a thickness of 5 mm or less.
<8> The road laying material according to any one of <1> to <7> above, wherein the magnetic material is made of a magnetic field responsive material magnetized by applying a magnetic field.
<9> The road laying object according to any one of <1> to <8> above, wherein the magnetic material is a ferrite magnet.
<10> A plurality of the magnetic markers are provided.
The road laying object according to any one of <1> to <9> above, wherein a plurality of magnetic markers are covered with one cover layer.
<11> The road laying structure according to any one of <1> to <10> above, wherein the cover layer is a layer that hides the magnetic marker from at least one of visible light and infrared light.
<12> The road laying object according to any one of <1> to <10> above, wherein the diffuse reflectance is less than 70%.
<13> The road laying object according to any one of <1> to <12> above, which has a length of 2 m or less.
<14> The road laying object according to any one of <1> to <13> above, which has a part that is easily broken than other parts.
<15> The road laying structure according to <14>, wherein the easily broken portions are provided at intervals of 5 mm or more and 2 m or less in the longitudinal direction.
<16> The road construction according to any one of <1> to <15> above, wherein the magnetic marker reflects at least one of millimeter waves and quasi-millimeter waves.
<17> The road laying object according to any one of <1> to <16> above, wherein the polarities of the magnetic markers are reversed at a predetermined pitch.

According to the present invention, it is possible to provide a road laying material which is excellent in durability and can be advantageously used for sensing using a magnetic sensor.

It is a figure which shows the structure of an example of a road construction, (a) is a plan view, (b) is a sectional view. It is a figure which shows the structure of another example of a road construction, (a) is a plan view, (b) is a sectional view. It is a figure which shows the structure of another example of a road construction, (a) is a plan view, (b) is a sectional view. It is a top view which shows the structure of still another example of a road construction. It is sectional drawing which shows the structure of the end part of a road laying thing, (a) shows the end part of a road laying thing which the end part of a magnetic marker is not chamfered, (b) is the end part of a magnetic marker chamfered Indicates the end of a road laying structure. It is sectional drawing which shows the structure of the road laying structure provided with the magnetic marker which has a thin part. (A) to (c) are explanatory views which show the example of the arrangement shape of the thin part. (A) to (c) are explanatory views which show the pattern example of the polar arrangement of the magnetic marker. (A) to (d) are plan views which show the arrangement example of the easily broken part. (A) to (c) are plan views which show the arrangement example of the cut. (A) to (e) are plan views showing a shape example of a through hole. (A) and (b) are cross-sectional views showing the shape of an example of an easily broken portion. It is a top view which shows another example of the shape of the easily broken part.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Here, the road laying object of the present invention is installed on the road surface or the like, and for example, in an automatic driving system or a driving support system, sensing is performed using a magnetic sensor installed in a vehicle or the like. It is used advantageously when specifying the current position of the vehicle.

(Road laying)
The road laying object of the present invention is laid on a road and includes a magnetic marker containing a magnetic material and a cover layer covering at least a part of the magnetic marker.

Specifically, as an example of the road laying object of the present invention, for example, the plan view shape of the road laying object 100 is shown in FIG. 1 (a), and the structure of the cross section along the longitudinal direction is shown in FIG. 1 (b). A square columnar magnetic marker 1 provided on the road surface G via the undercoat layer 2 and a cover layer 3 covering at least a part (all in the illustrated example) of the magnetic marker 1 are provided. The undercoat layer 2 is a member arbitrarily provided for the purpose of, for example, smoothing unevenness and / or imparting adhesive force. Further, in the illustrated example, from the viewpoint of enhancing the visibility of the road laying object 100, the cover layer 3 is provided with glass beads 4 as a retroreflecting material of visible light.
Further, in another example of the road laying object of the present invention, for example, the plan view shape of the road laying object 100A is shown in FIG. 2A, and the structure of the cross section along the longitudinal direction is shown in FIG. 2B. A band-shaped magnetic marker 1A provided on the road surface G via the undercoat layer 2 and a cover layer 3 covering at least a part (all in the illustrated example) of the magnetic marker 1A are provided.
Further, in another example of the road laying object of the present invention, for example, the plan view shape of the road laying object 100B is shown in FIG. 3A, and the structure of the cross section along the longitudinal direction is shown in FIG. 3B. A sheet-shaped magnetic marker 1B provided on the road surface G via the undercoat layer 2 and a cover layer 3 covering at least a part (all in the illustrated example) of the magnetic marker 1B are provided. Although FIG. 3 shows a case where the magnetic marker has a rectangular sheet shape, the shape of the sheet-shaped magnetic marker is not limited to the rectangular shape, and the magnetic marker of the road laying object of the present invention is, for example, FIG. It may be a circular sheet-shaped magnetic marker 1C such as the road laying object 100C shown in 1.

Since the road laying object of the present invention has a magnetic marker, it can be satisfactorily sensed by using a magnetic sensor. Further, since the road laying object of the present invention has a cover layer, even when the road laying object is repeatedly stressed due to a vehicle traveling on the road passing over the road laying object or the like. , It is possible to suppress the early deterioration of the magnetic marker. Therefore, the road laying object of the present invention has excellent durability and can be advantageously used for sensing using a magnetic sensor.

<Magnetic marker>
Here, as the magnetic marker containing a magnetic material, any magnetic marker can be used as long as it can generate a magnetic field of a desired magnitude at a desired position according to the purpose of sensing using a magnetic sensor. Markers can be used.
Above all, from the viewpoint of handleability, the magnetic marker is formed by molding a polymer composition containing a polymer component such as rubber or resin such as a bond magnet and a magnetic material, and optionally further containing an additive. It is preferable to use a molded product. The molded product may be further coated with a covering material such as resin.

[Magnetic material]
As the magnetic material, for example, a soft magnetic material and / or a hard magnetic material can be used. Among them, as the magnetic material, it is preferable to use a magnetic material made of a magnetic field responsive material magnetized by the application of a magnetic field, and it is more preferable to use a ferrite magnet having excellent rust resistance.

[shape]
The shape of the magnetic marker can be a shape according to the purpose of sensing using a magnetic sensor, and is not particularly limited, and is, for example, a particle shape, a rod shape, a columnar shape, a block shape, a sheet shape, a strip shape, or the like. can do.
Above all, from the viewpoint of ease of laying, the shape of the magnetic marker is preferably sheet-shaped or strip-shaped.

The plan-view shape of the magnetic marker has a width of preferably 3 mm or more, more preferably 30 mm or more, further preferably 100 mm or more, preferably 700 mm or less, and preferably 500 mm or less. It is more preferably present, and further preferably 300 mm or less. When the width is equal to or more than the above lower limit value, the magnetic field can be generated sufficiently far. Further, if the width is equal to or less than the above upper limit value, the position can be grasped with high accuracy when used for specifying the current position of the vehicle.
Further, the plan-view shape of the magnetic marker preferably has a longitudinal dimension of 3 mm or more, more preferably 30 mm or more, and further preferably 100 mm or more. When the dimension in the longitudinal direction is equal to or more than the above lower limit value, the magnetic field can be generated sufficiently far. The dimension in the longitudinal direction can be any length as long as it is equal to or less than the length of the road laying object.

Further, it is preferable that the end portion of the magnetic marker has a shape in which the cover layer 3 side is chamfered, as shown in FIG. 5B, for example. If the cover layer 3 side of the end 10 of the magnetic marker 1 is chamfered as shown in FIG. 5 (b), it is compared with the magnetic marker 1 having an unchamfered end as shown in FIG. 5 (a). Even when a vehicle traveling on the road passes over a road laying object, it is possible to prevent the cover layer 3 covering the end portion of the magnetic marker 1 from being deteriorated at an early stage.

From the viewpoint of suppressing the generation of stress even when a vehicle traveling on the road passes over the road laying material and suppressing the early deterioration of the cover layer covering the end of the magnetic marker. For example, as shown in FIG. 6, it is preferable that the magnetic marker 1D is provided with a thin thin portion 11 and the Young's modulus of the cover layer 3 is made larger than the Young's modulus of the magnetic marker 1D. The thin portion 11 is less likely to be deformed when an external force is applied from above as compared with the portion 12 located between the thin portions 11. However, if the Young's modulus of the cover layer 3 is made larger than that of the magnetic marker 1D, the cover layer 3 Supports the portion 12, and the entire deformation is suppressed. In addition, stress transmission can be suppressed even when an external force (shear force) is received from the side. Further, even if the cover layer 3 is cracked, the propagation of the crack can be suppressed at the portion where the thin portion 11 having a thick cover layer 3 is located.

Here, the arrangement shape of the thin portion 11 in a plan view is not particularly limited, and may be, for example, a grid pattern as shown in FIG. 7A, or as shown in FIG. 7B. It may be striped (vertical striped in the illustrated example) or dot-shaped as shown in FIG. 7 (c). Above all, the arrangement shape of the thin portion 11 in a plan view is preferably a shape extending linearly over the entire width of the magnetic marker 1D as shown in FIGS. 7A and 7B. .. If the thin portion 11 is formed linearly over the entire width of the magnetic marker 1D, the magnetic marker 1D is placed so that the extending direction of the thin portion 11 is the axial direction when the magnetic marker 1D is stored or transported. This is because it can be easily wound.

The arrangement pitch of the thin portion 11 is 2 mm or more from the viewpoint of supporting the portion 12 and satisfactorily suppressing the overall deformation when an external force is received from above while enabling good sensing by the magnetic sensor. It is preferably 4 mm or more, more preferably 5 mm or more, preferably 500 mm or less, more preferably 200 mm or less, and further preferably 100 mm or less.

Further, the width of the thin portion 11 (that is, the distance between the portions 12) supports the portion 12 when an external force is received from above while enabling good sensing by the magnetic sensor, and suppresses the overall deformation satisfactorily. From the viewpoint of the above, the arrangement pitch is preferably 5% or more, more preferably 10% or more, preferably 50% or less, and more preferably 30% or less.

Further, the thickness of the thin portion 11 is preferably 80% or less of the average thickness of the magnetic marker 1D from the viewpoint of supporting the portion 12 when receiving an external force from above and satisfactorily suppressing the overall deformation. , 50% or less, more preferably 30% or less. A part of the thin portion may penetrate. Further, when the thin portion is independent of each other as shown in FIG. 7 (c), the thin portion may be completely penetrated. The thickness of the thin portion 11 is usually 5% or more of the average thickness of the magnetic marker 1D.

[Characteristics]
The magnetic marker is not particularly limited and preferably has, for example, the following properties.

That is, the magnetic marker is preferably capable of reflecting millimeter and / or quasi-millimeter waves, and more preferably capable of reflecting millimeter and quasi-millimeter waves. This is because if the magnetic marker can reflect millimeter waves and / or quasi-millimeter waves, sensing using a millimeter-wave radar or a quasi-millimeter-wave radar can also be performed.
In the present invention, "reflection" includes reflections other than specular reflection such as diffuse reflection.

Further, in the magnetic marker, the thickness t and the Young's modulus E at a temperature of 60 ° C. preferably satisfy the following relational expression (1), more preferably the following relational expression (1'), and are described below. It is more preferable to satisfy the relational expression (1 ″).
E / t ≧ 3 × 10 ⁹ [Pa / m] ・ ・ ・ (1)
E / t ≧ 6 × 10 ⁹ [Pa / m] ・ ・ ・ (1')
E / t ≧ 10 × 10 ⁹ [Pa / m] ・ ・ ・ (1 ”)
If the thickness t and Young's modulus E at a temperature of 60 ° C. satisfy the above relational expression, deformation of the magnetic marker is suppressed even when a vehicle traveling on the road passes over a road laying object. Therefore, it is possible to prevent the cover layer from being deteriorated at an early stage. Here, the Young's modulus E at a temperature of 60 ° C. is adopted in consideration of the road surface temperature in summer.

Further, in the magnetic marker, the thickness t and the Young's modulus E at a temperature of 60 ° C. preferably satisfy the following relational expression (2), and more preferably the following relational expression (2'). It is more preferable to satisfy the relational expression (2 ").
E × t ≦ 4 × 10 ⁶ [Pa ・ m] ・ ・ ・ (2)
E × t ≦ 2 × 10 ⁶ [Pa ・ m] ・ ・ ・ (2')
E × t ≦ 1 × 10 ⁶ [Pa ・ m] ・ ・ ・ (2 ”)
If the thickness t and the Young's modulus E at a temperature of 60 ° C. satisfy the above relational expression, the handleability of the magnetic marker and the workability of the road laying material can be sufficiently improved.

<Cover layer>
The cover layer covers at least a part of the magnetic marker, and the cover layer is not particularly limited, and is, for example, a sheet having an adhesive layer or a paint containing a synthetic resin, a pigment, an extender, and a plasticizer. Examples include layers consisting of.

Here, from the viewpoint of protecting the magnetic marker, the cover layer is preferably provided so as to cover the entire magnetic marker.
On the other hand, from the viewpoint of suppressing the early deterioration of the cover layer even when a vehicle traveling on the road passes over the road laying, the cover layer completely covers the end of the magnetic marker. Is preferably not covered (ie, in plan view, the edge of the cover layer is located on the edge of the magnetic marker or inside the edge of the magnetic marker).

Further, the cover layer is preferably a layer that hides the magnetic marker with respect to at least one of visible light and infrared light. By hiding the magnetic marker against at least one of visible and infrared light, the driver and other sensors in the vehicle (eg, visible light camera, infrared camera, infrared laser radar, etc.) It is possible to prevent giving false recognition to the camera. The layer that hides the magnetic marker from at least one of visible light and infrared light can be formed by containing a dye, a pigment, or a material having light scattering properties.
Further, the cover layer is preferably a layer having a diffuse reflectance of less than 70%. If the diffuse reflectance is less than 70%, it prevents the driver and other sensors mounted on the vehicle (for example, a visible light camera, an infrared camera, an infrared laser radar, etc.) from giving false recognition. be able to. The layer having a diffuse reflectance of less than 70% can be formed by containing a dye or a pigment. The diffuse reflectance can be measured in accordance with JIS K5665.
Further, if the road laying material is to have a function as a road marking such as a lane marking, the cover layer should be a layer that hides the color of the road surface on which the road laying material is installed and exhibits a color different from the road surface. Is preferable.

<Structure and shape of road construction>
The road laying structure provided with the above-mentioned magnetic marker and cover layer is not particularly limited, and may have an arbitrary shape and structure according to the purpose of sensing.

Specifically, the plan view shape of the road laying object is not particularly limited, and may be, for example, a polygonal shape such as a quadrangular shape, a substantially polygonal shape with rounded corners, a circular shape, or a strip shape. it can. Above all, from the viewpoint of ease of formation, the plan view shape of the road laying material is preferably a strip shape, a square shape, or a square shape with rounded corners.

Further, the thickness of the road laying object is preferably 5 mm or less. When the thickness is 5 mm or less, it is possible to prevent the road laying object from hindering the traveling of automobiles and the like.

Further, the length of the road laying object is preferably 2 m or less, more preferably 1 m or less, and further preferably 50 cm or less. When the length of the road laying object is not more than the above upper limit value, it is possible to suppress erroneous recognition and hindering the running of automobiles and the like when the road laying object is peeled off from the road surface. From the viewpoint of enabling good sensing by the magnetic sensor, the length of the road laying object is preferably 10 mm or more. Further, when the length of the road laying object is longer than the above upper limit value, it is preferable that the road laying object is provided with an easily broken portion described later.

When a plurality of road laying objects are arranged intermittently, the distance between the road laying objects is preferably 50 m or less, preferably 20 m or less, from the viewpoint of enabling good sensing by the magnetic sensor. It is more preferable that it is 10 m or less.

Further, when the road laying material is provided with a plurality of magnetic markers, each magnetic marker may be individually covered with a cover layer, but from the viewpoint of ease of construction, the plurality of magnetic markers are covered by one cover layer. It is preferably covered.

Further, the road laying structure may have only one polarity, but the polarity of the magnetic marker may be reversed at a predetermined pitch toward an arbitrary direction such as the traveling direction of the vehicle. By reversing the polarity of the magnetic marker at a predetermined pitch, it is possible to give information according to the reversal pitch of the polarity when sensing with a magnetic sensor, and to easily identify the road laying object to be detected. Can be done. Specifically, it is possible to give digital information with the south pole set to "1" and the north pole set to "0", and to distinguish it from other magnetic markers having different polar inversion pitches.
The polarity may be reversed with a non-magnetized portion (non-magnetized portion) in between. Moreover, the polarity may be inverted within one magnetic marker, or may be inverted for each magnetic marker.

Specifically, the polarity of the magnetic marker is such that the N pole 1N and the S pole 1S are adjacent to each other and alternately located, as shown in FIG. 8A, for example, when the band-shaped magnetic marker 1A is magnetized. It may be inverted as follows.
Further, as for the polarity of the magnetic marker, as shown in FIG. 8B, for example, when the band-shaped magnetic marker 1A is magnetized, the N pole 1N and the S pole 1S alternate with each other via the non-magnetized portion NM. It may be inverted so that it is positioned.
Further, the polarities of the magnetic markers alternate between the N pole 1N and the S pole 1S between adjacent magnetic markers 1B, as shown in FIG. 8C, for example, when the sheet-shaped magnetic marker 1B is magnetized. It may be inverted so as to be replaced with.

If two poles having different polarities are close to each other, the magnetic field lines may not reach far and the magnetic field may be weakened. Therefore, the polarity is reversed with a non-magnetized portion (non-magnetized portion) in between, or the length per pole is lengthened (for example, preferably 1.5 times the width of the magnetic marker). Above, more preferably, it is doubled or more).

Further, it is preferable that the road laying structure has a part that is easily broken than other parts. If the road laying material deteriorates and part or all of the road laying material is peeled off from the road surface, the peeled road laying material may cause misrecognition or hinder the running of automobiles or the like. However, if the road laying material has an easily broken part, the road laying material may be peeled off as a broken piece, or the peeled road laying material may be easily broken into a small piece. It is possible to suppress the hindrance to the running of a car or the like.

The road laying object preferably has a plurality of easily broken portions, and the plurality of easily broken portions are more preferably provided at predetermined intervals in the longitudinal direction of the road laying object. Further, the arrangement interval of the easily broken portions of the road laying material is preferably 1 mm or more, more preferably 5 mm or more, preferably 2 m or less, more preferably 1 m or less, and 50 cm. The following is more preferable. When the arrangement interval of the easily broken portions is equal to or more than the above lower limit value, it is possible to suppress an excessive decrease in the strength of the road laying material. Further, if the arrangement interval of the easily broken portions is equal to or less than the above upper limit value, the road laying material can be broken into small pieces having sufficiently small dimensions.

The arrangement position of the easily broken portion is not particularly limited, and may be a position that does not overlap with the arrangement position of the magnetic marker, or may be a position that overlaps with the arrangement position of the magnetic marker. Further, the easily broken portion may be formed by providing a structure that is easily broken only in the cover layer, or may be formed by providing a structure that is easily broken only in the magnetic marker, or the cover layer and the magnetic marker. It may be formed by providing a structure that is easily broken. Here, when the above-mentioned thin portion is provided on the magnetic marker, the thin portion can be used as the structure that is easily broken.

The shape of the easily broken portion is not particularly limited, and may be any shape. Specifically, the arrangement shape of the easily broken portion can be, for example, a shape as shown in FIGS. 9A to 9D. In FIGS. 9 (a) to 9 (d), the magnetic markers are not shown for the sake of simplicity.

Here, in FIG. 9A, easily broken portions 50 are formed at predetermined intervals in the longitudinal direction of the road laying object 100, and the easily broken portions 50 are less likely to break than the easily broken portions 50. The other part 60 is located.
Further, in FIG. 9B, the easily broken portion 50 is formed in a grid pattern on the road laying object 100, and the portion surrounded by the easily broken portion 50 is a portion that is more difficult to break than the easily broken portion 50. 60 is located.
Further, in FIG. 9C, the easy-breaking portion 50 is formed in a rhombic lattice pattern on the road laying object 100, and the portion surrounded by the easy-breaking portion 50 is another portion that is harder to break than the easy-breaking portion 50. 60 is located.
Further, in FIG. 9D, a curved easy-breaking portion 50 intersecting in a substantially rhombic lattice shape is formed in the road laying structure 100, and the portion surrounded by the easy-breaking portion 50 is larger than the easy-breaking portion 50. The other portion 60, which is difficult to break, is located.

Among the above, from the viewpoint of high degree of freedom in arranging the magnetic marker, the arrangement shape of the easily broken portion is preferably the arrangement shape shown in FIG. 9A.

The easily broken portion is not particularly limited, and is, for example, (1) formation of a through hole, (2) formation of a thin portion, (3) formation of a low-strength material portion, and (4) a short road laying structure. It can be formed by a method such as joining each other. Above all, the method (1) above is preferable from the viewpoint of the timing of forming the easily broken portion and the high degree of freedom in design.
In the following, the method of forming the easily broken portion will be described as an example of a case where the easily broken portion is formed by providing a structure that easily breaks in the cover layer, but as described above, the easily broken portion is only a magnetic marker. Alternatively, the cover layer and the magnetic marker may be formed by providing a structure that is easily broken by the following method.

Here, the through hole of (1) may be a notch as shown in FIG. 10, for example, or a small hole which is continuously arranged at short intervals in a perforation pattern as shown in FIG. 11, for example. You may.

In the road laying structure 100 shown in FIG. 10A, notches 51 extending in the width direction are formed at both ends of the cover layer 3 in the width direction, and a portion located between the notches 51 facing each other in the width direction is an easily broken portion. It has become.
Further, in the road laying structure 100 shown in FIG. 10B, a notch 51 extending in the width direction is formed in the center of the cover layer 3 in the width direction, and the portion where the notch 51 is formed is an easily broken portion. ..
Further, in the road laying structure 100 shown in FIG. 10C, notches 51 extending in a direction inclined with respect to the width direction are formed at both ends in the width direction of the cover layer 3, and between the notches 51 facing each other in the width direction. The part located at is the easily broken part.
In addition, in FIGS. 10A and 10C, the cuts 51 are provided at both ends in the width direction of the cover layer 3, but the cuts may be provided only on one side in the width direction of the cover layer. Further, the shape of the notch may be curved or polygonal. Further, the notch may be provided so as to extend in the longitudinal direction of the road laying.

In the road laying structure 100 shown in FIGS. 11A to 11E, small holes 52A to 52E are formed at short intervals in a perforated manner in the width direction, and small holes 52A to 52E are formed. Is an easily broken part. Here, the small hole 52A is a linear hole, the small hole 52B is a diamond-shaped hole, the small hole 52C is a circular hole, and the small hole 52D is a curved hole arranged in two rows. The small holes 52E are bent linear holes arranged in two rows.
The small holes may be provided at short intervals in a perforated manner in the longitudinal direction of the road laying structure.

Further, the thin portion of the above (2) can have a structure such that, for example, FIGS. 12 (a) and 12 (b) show a cross section along the longitudinal direction.

Here, the thin portion 53A shown in FIG. 12A has a recess formed on one surface of the cover layer 3. Further, the thin portion 53B shown in FIG. 12B has recesses formed on both surfaces of the cover layer 3. Then, in the road laying structure shown in FIG. 12, the portion provided with the thin portions 53A and 53B becomes an easily broken portion, and the cover layer 3 located between the thin portions 53A and 53B and thicker than the thin portions 53A and 53B 3 The part becomes another part that is harder to break than the easily broken part.
The thin portion may be provided only in a part of the road laying material in the width direction, or may be provided in the entire part. Further, the thin portion may be provided so as to extend in the longitudinal direction of the road construction.

Further, the low-strength material portion of the above (3) can be formed by using a material having a smaller amount of reinforcing material than other portions or containing no reinforcing material, for example. In a road laying structure having a low-strength material part, the low-strength material part becomes an easily broken part, and other parts (a part made of a material having a higher strength than the low-strength material part) are less likely to break than the easily broken part. It will be the other part.
The low-strength material portion may be provided only in a part of the road laying material in the width direction, or may be provided in the whole part. Further, the low-strength material portion may be provided so as to extend in the longitudinal direction of the road construction.

Then, as shown in FIG. 13, for example, the joining of the short road laying objects in (4) above is performed by sewing the cover layers 3 of the short road laying objects together with the thread 54 at the joining portion 21. Can be done. The joining method is not limited to suturing, and short road laying objects may be entangled with each other, meshed with each other, or bonded together.
The joints may be provided only in a part of the short road laying structure in the width direction, or may be provided in all of them. Further, the joint portion may be provided so as to extend in the longitudinal direction of the short road construction.

<Construction method>
The road laying material is not particularly limited, for example, (1) a method of installing a magnetic marker on the road surface and then covering it with a cover layer, or (2) a laminated body of the magnetic marker and the cover layer in advance. It can be prepared and installed on the road surface by using a method of installing the laminated body on the road surface or the like. Specifically, in the method (1) above, for example, a sheet-shaped magnetic marker is laid on the road surface, and then a cover layer made of paint is applied to install the road laying object on the road surface. Can be done.
The place where the road laying object of the present invention is laid on the road is not limited to the road surface, but may be on the surface of a road accessory such as a guardrail, a curb, or a utility pole.

According to the present invention, it is possible to provide a road laying material which is excellent in durability and can be advantageously used for sensing using a magnetic sensor.

1,1A, 1B, 1C, 1D Magnetic marker 1N N pole 1S S pole 2 Undercoat layer 3 Cover layer 4 Glass beads 10 End 11 Thin part 12 Part 50 Easy break part 51 Cut 52A to 52E Small holes 53A, 53B Thin part 60 Other parts 100, 100A, 100B, 100C Road laying material G Road surface NM Non-magnetized part

Claims (17)

It is a road laying thing laid on the road,
A road laying structure comprising a magnetic marker containing a magnetic material and a cover layer covering at least a part of the magnetic marker. In the magnetic marker, the thickness t and Young's modulus E at a temperature of 60 ° C. have the following relational expression (1):
E / t ≧ 3 × 10 ⁹ [Pa / m] ・ ・ ・ (1)
The road laying object according to claim 1, which satisfies the above conditions. In the magnetic marker, the thickness t and Young's modulus E at a temperature of 60 ° C. have the following relational expression (2):
E × t ≦ 4 × 10 ⁶ [Pa ・ m] ・ ・ ・ (2)
The road laying according to claim 1 or 2, which satisfies the above conditions. The road laying object according to any one of claims 1 to 3, wherein the magnetic marker is chamfered on the cover layer side of the end portion. The road laying according to any one of claims 1 to 4, wherein the edge of the cover layer is located on the edge of the magnetic marker or inside the edge of the magnetic marker in a plan view. The Young's modulus of the cover layer is larger than the Young's modulus of the magnetic marker.
The road construction according to any one of claims 1 to 5, wherein the magnetic marker has a thin and thin portion. The road laying object according to any one of claims 1 to 6, which has a thickness of 5 mm or less. The road construction according to any one of claims 1 to 7, wherein the magnetic material is made of a magnetic field responsive material magnetized by applying a magnetic field. The road laying object according to any one of claims 1 to 8, wherein the magnetic material is a ferrite magnet. With a plurality of the magnetic markers
The road laying according to any one of claims 1 to 9, wherein a plurality of magnetic markers are covered with one cover layer. The road construction according to any one of claims 1 to 10, wherein the cover layer is a layer that conceals the magnetic marker from at least one of visible light and infrared light. The road laying according to any one of claims 1 to 10, wherein the diffuse reflectance is less than 70%. The road laying object according to any one of claims 1 to 12, which has a length of 2 m or less. The road laying object according to any one of claims 1 to 13, further comprising an easily broken portion that is more easily broken than the other portion. The road laying object according to claim 14, wherein the easily broken portions are provided at intervals of 5 mm or more and 2 m or less in the longitudinal direction. The road construction according to any one of claims 1 to 15, wherein the magnetic marker reflects at least one of millimeter wave and quasi-millimeter wave. The road laying object according to any one of claims 1 to 16, wherein the polarities of the magnetic markers are reversed at a predetermined pitch.

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