Magnetic marker, magnetic marker embedding fixture, and magnetic marker embedding method

Abstract

The present invention discloses a magnetic marker, a magnetic marker embedding fixture, and a magnetic marker embedding method. The magnetic marker is embedded in a road and is configured to be detected by a magnetic sensor mounted on a vehicle. The magnetic marker comprises a housing that houses a magnet and a protective material covering the magnet; and an anchor protruding downward from the housing and configured to expand in diameter when embedded in the road.

Description

Technical Field

[0001] The present invention relates to a magnetic marker buried in a road for magnetic induction of a vehicle, a magnetic marker burying jig, and a magnetic marker burying method. Background Art

[0002] Magnetic markers are part of a magnetic vehicle position detection system (hereinafter referred to as the Global Magnetic Positioning System (GMPS)). GMPS uses magnetic sensors installed on vehicles to detect magnetic markers placed on the road, thereby estimating the vehicle's position and supporting advanced vehicle control such as automated driving.

[0003] Japanese Patent Application Laid-Open No. 2000-215391 discloses a magnetic marker embedded in a road. The process of embedding the magnetic marker in a road generally involves drilling a hole in the road, embedding the magnetic marker in the hole, and pouring a liquid protective material and allowing it to solidify to cover the embedded magnetic marker. Summary of the Invention

[0004] However, in the above-mentioned work of burying the magnetic marker in the road, since it takes time for the liquid protective material to dry and solidify, the work time is longer than necessary.

[0005] The present invention provides a magnetic marker, a magnetic marker embedding fixture, and a magnetic marker embedding method capable of shortening the operation time of embedding the magnetic marker.

[0006] A first aspect of the present invention relates to a magnetic marker embedded in a roadway and configured to be detected by a magnetic sensor mounted on a vehicle. The magnetic marker comprises a housing that houses a magnet and a protective material covering the magnet; and an anchor that protrudes downward from the housing and is configured to expand in diameter when embedded in the roadway.

[0007] In the magnetic marker of this aspect, the anchor may have: a sleeve, whose upper end portion is fixed to the shell; and an expansion member, which is configured to be movably fitted in the sleeve with clearance along the axial direction, and an axial cut is formed at the lower portion of the sleeve, and the lower portion of the expansion member has an expansion portion, which protrudes from the sleeve and expands downward, and the expansion member can be configured to be pushed upward by being buried, so that the lower portion of the sleeve expands.

[0008] The diameter of the housing and the diameter of the anchor may be substantially the same.

[0009] A second aspect of the present invention relates to a magnetic marker embedding jig for embedding a magnetic marker in a road. The embedding jig may include: a base disposed around a magnetic marker inserted into a hole formed in the road surface, the base accommodating the magnetic marker within its inner diameter; and a pusher having a larger diameter than the outer diameter of the housing and configured to be inserted into the inner diameter of the base.

[0010] A third aspect of the present invention relates to a method for embedding a magnetic marker in a road. The embedding method may include drilling a hole in the road, inserting the magnetic marker into the hole, and expanding the diameter of the anchor member by moving the diameter expander upward relative to the sleeve.

[0011] According to the magnetic marker, the magnetic marker embedding jig, and the magnetic marker embedding method of aspects of the present invention, it is possible to shorten the working time for embedding the magnetic marker. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Features, advantages, and technical and industrial significance of exemplary embodiments of the present invention are described below with reference to the accompanying drawings, in which like reference numerals refer to like elements.

[0013] Figure 1 Schematic diagram showing a magnetic vehicle position detection system according to an embodiment.

[0014] Figure 2A Schematic diagram showing a magnetic marker as an example of an embodiment.

[0015] Figure 2B Schematic diagram showing a magnetic marker as an example of an embodiment.

[0016] Figure 3 Schematic diagram showing a magnetic label as another example of the embodiment.

[0017] Figure 4 Schematic diagram showing a magnetic marker embedding jig as an example of an embodiment.

[0018] Figure 5 This is a flowchart showing the flow of a magnetic marker embedding step as an example of an embodiment.

[0019] Figure 6A This is a schematic diagram showing the flow of a magnetic mark embedding step as an example of an embodiment.

[0020] Figure 6B This is a schematic diagram showing the flow of a magnetic mark embedding step as an example of an embodiment.

[0021] Figure 6C This is a schematic diagram showing the flow of a magnetic mark embedding step as an example of an embodiment. DETAILED DESCRIPTION

[0022] In the following description, specific shapes, materials, directions, numerical values, etc. are examples for facilitating understanding of the present invention and may be modified as appropriate depending on the application, purpose, specifications, etc.

[0023] use Figure 1 , a magnetic vehicle position detection system 10 according to an embodiment will be described. Figure 1 1 is a schematic diagram showing the magnetic vehicle position detection system 10 .

[0024] like Figure 1 As shown, the magnetic marker 20 of the present invention is a component that forms part of a magnetic vehicle position detection system 10 (hereinafter referred to as a GMPS (Global Magnetic Positioning System)). GMPS 10 uses a magnetic sensor installed on a vehicle 11 to detect magnetic markers 20 installed on a road 13, thereby estimating the position of the vehicle 11 and supporting advanced vehicle control such as automated driving.

[0025] use Figure 2A and 2B , a magnetic marker 20 as an example of an embodiment will be described. Figure 2A and 2B 2 is a schematic diagram showing the magnetic marker 20 .

[0026] The magnetic marker 20 is a component constituting a portion of the GMPS 10 , is buried in the road surface of the road 13 , and is detected by a magnetic sensor installed in the vehicle 11 .

[0027] like Figure 2A and 2B As shown, the magnetic marker 20 includes a housing 23 that houses a magnet 21 and a protective material 22 that covers the magnet 21 , and an anchor 24 that protrudes downward from the housing 23 and expands in diameter when buried in the road 13 .

[0028] Magnetic marker 20 is embedded in countersunk hole 14 formed in the road surface of road 13. Countersunk hole 14 consists of large diameter hole 14A for embedding housing 23 and small diameter hole 14B formed below large diameter hole 14A for inserting anchor 24. Countersunk hole 14 is bored by a countersunk drill.

[0029] The magnet 21 generates a magnetic force detectable by a magnetic sensor installed on the vehicle 11. As the magnet 21, an isotropic ferrite plastic magnet or ferrite rubber magnet formed into a cylindrical shape and having iron oxide magnetic powder as the magnetic material dispersed in a polymer material (non-conductive material) as a base material is preferably used.

[0030] Protective material 22 covers magnet 21, protecting it from direct sunlight, rain, pressure and vibration from passing vehicles, friction from braking, and wear from snowmelt spray and tire chains during winter. In this example, protective material 22 is preferably a cylindrical resin having a diameter substantially the same as that of magnet 21. Protective material 22 can be in a solid state and bonded and secured to magnet 21 and housing 23 using an adhesive. Alternatively, protective material 22 can be in a liquid state, poured into housing 23 housing magnet 21, and then solidified, thereby securing magnet 21.

[0031] The housing 23 houses the magnet 21 and the protective material 22. The housing 23 allows the magnet 21 to be covered with the protective material 22 before being buried in the road 13. Therefore, when using the liquid protective material 22 after solidification, the protective material 22 can be solidified in the housing 23 before the housing 23 is buried in the road 13. As a result, the time required to bury the magnetic marker 20 in the road 13 can be shortened.

[0032] Furthermore, since the protective material 22 can be filled into the housing 23 in a factory, the filling amount of the protective material 22 and the flatness of the upper surface of the protective material 22 can be managed all at once.

[0033] Furthermore, when using a solid protective material 22, since the protective material 22 can be fixed to the housing 23 in a factory or the like, it is possible to manage the gap between the protective material 22 and the housing 23, the adhesion between the protective material 22 and the housing 23, and the flatness of the upper surface of the protective material 22. This improves the quality of the protective material 22.

[0034] The shell 23 is formed into a cylindrical shape with a closed bottom and an open top. The shell 23 is preferably made of a non-magnetic body. An anchor 24 protruding downward is fixed to the bottom surface of the shell 23. The bottom portion of the shell 23 is provided with a recess 23A open at the bottom, which can accommodate the upper end of the expander 26 when the upper end of the expander 26 rises in the sleeve 25. The recess 23A is a portion for the expander 26 to be retracted when the sleeve 25 described later is expanded when the magnetic marker 20 is buried in the counterbore 14. The length of the shell 23 is the same as the length of the large diameter hole 14A of the counterbore 14. The outer diameter of the shell 23 is the same as the diameter of the large diameter hole 14A of the counterbore 14.

[0035] The anchor 24 is expanded while the magnetic marker 20 is embedded in the counterbore 14. More specifically, the magnetic marker 20 is inserted into the counterbore 14, and the expander 26 reaches the bottom of the small-diameter hole 14B of the counterbore 14. Further insertion of the magnetic marker 20 causes the expander 26 to move upward relative to the sleeve 25, expanding the lower portion of the sleeve 25 and thereby preventing the anchor 24 from falling out of the counterbore 14.

[0036] The anchors 24 can securely fix the magnetic markers 20 by driving them into the countersunk holes 14 formed on the road 13, as will be described later. This allows operators with ordinary anchor driving skills to easily embed the magnetic markers 20 in the road 13.

[0037] The anchor 24 is formed in a substantially cylindrical shape having a diameter smaller than that of the housing 23. The anchor 24 includes a cylindrical sleeve 25 and an elongated diameter-enlarging member 26 loosely fitted in the sleeve 25 so as to be movable in the axial direction.

[0038] The upper end of sleeve 25 is fixed to the bottom surface of housing 23. An axial cutout 25A is formed in the lower portion of sleeve 25. The length of sleeve 25 is the same as the length of small-diameter hole 14B of counterbore 14. Furthermore, the outer diameter of sleeve 25 is the same as the diameter of small-diameter hole 14B.

[0039] The enlarged diameter portion 26A that is enlarged downward is provided at the lower portion of the enlarged diameter member 26. Figure 2A The expanded portion 26A protrudes from the sleeve 25 before being embedded. The maximum diameter of the expanded portion 26A is the same as the outer diameter of the sleeve 25 and the diameter of the small-diameter hole 14B. Therefore, when the sleeve 25 is inserted into the small-diameter hole 14B, the expanded portion 26A does not interfere with the insertion. The expanded member 26 moves upward relative to the sleeve 25 and retracts into the recessed portion 23A of the housing 23, thereby increasing the sleeve 25 by the cylindrical thickness of the sleeve 25.

[0040] use Figure 3 , a magnetic marker 30 as another example of an embodiment will be described. Figure 3 3 is a schematic diagram showing the magnetic marker 30 .

[0041] The magnetic marker 30 is configured such that the diameter of the cylindrical housing 33 is substantially the same as the diameter of the cylindrical anchor 34. In this example, the diameters of the magnet 31, the protective material 32, and the housing 33 of the magnetic marker 30 are smaller than those of the magnetic marker 20.

[0042] According to the magnetic marker 30, in the method for embedding the magnetic marker 30 described below, the magnetic marker 30 can be embedded using only a conventional drill without using a countersink drill to drill the countersink 14 in the road surface 13. This improves the efficiency of embedding the magnetic marker 30.

[0043] use Figure 4 , a jig 40 for embedding the magnetic marker 20 as an example of an embodiment will be described. Figure 4 Schematic diagram showing the embedding jig 40 .

[0044] In the embedding process of the magnetic marker 20, which will be described in detail later, the embedding jig 40 is used to drive the magnetic marker 20 into the countersunk hole 14 drilled in the road 13. The embedding jig 40 enables the upper surface of the magnetic marker 20 (the upper surface of the protective material 22) to be flush with the surface of the road 13, as will be described in detail later.

[0045] The embedding jig 40 includes a pusher 41 having a diameter larger than the inner diameter of the housing 23 of the magnetic marker 20 , and a base 42 through which the pusher 41 passes.

[0046] The pusher 41 includes a metal cylindrical body 41A having a diameter slightly larger than the outer diameter of the housing 23 of the magnetic marker 20 and a metal disc-shaped flange 41B having a larger diameter than the outer diameter of the body 41A. The body 41A may be cylindrical and thicker than the housing 23 of the magnetic marker 20.

[0047] According to the pusher 41 , when the magnetic marker 20 is driven into the counterbore 14 by a hammer, for example, the protective material 22 of the magnetic marker 20 is not damaged because the pusher 41 acts as a buffer between the hammer and the magnetic marker 20 .

[0048] The base 42 is formed into a metal annular shape having an inner diameter slightly larger than the diameter of the main body 41A of the pusher 41. The height of the base 42 is preferably substantially the same as the height of the main body 41A of the pusher 41.

[0049] By driving the pusher 41 into the base 42 until the flange 41B of the pusher 41 contacts the upper surface of the base 42, the upper surface of the magnetic marker 20 (the upper surface of the protective material 22) can be flush with the surface of the road 13. Furthermore, since the pusher 41 is guided vertically by the base 42, the magnetic marker 20 can be driven vertically into the countersunk hole 14.

[0050] use Figure 5 and Figures 6A to 6C , a description will be given of a process for embedding the magnetic marker 20 as an example of an embodiment.

[0051] In the step of embedding the magnetic markers 20 as a method of embedding the magnetic markers 20 , the magnetic markers 20 are embedded using the embedding jig 40 .

[0052] In step S11, a countersink 14 consisting of a large diameter hole 14A and a small diameter hole 14B is drilled in the road 13 at the location where the magnetic marker 20 is buried (see FIG. Figure 6A It should be noted that, as described above, if the diameter of the housing 33 of the magnetic marker 30 is substantially the same as the diameter of the anchor 34, then drilling can be performed using only an ordinary drill.

[0053] In step S12, dust is removed from countersunk hole 14 using a vacuum cleaner or dust removal pump. In step S13, magnetic marker 20 is inserted into countersunk hole 14. In step S14, base 42 of embedding fixture 40 is positioned around countersunk hole 14 and magnetic marker 20, and pusher 41 of embedding fixture 40 is inserted into base 42.

[0054] In step S15, the pusher 41 of the embedding jig 40 is struck with a hammer or the like until the lower end of the enlarged diameter member 26 of the anchor member 24 of the magnetic marker 20 reaches the bottom of the small diameter hole 14B (see FIG. Figure 6B ).

[0055] In step S16, the pusher 41 is further struck with a hammer or the like, so that the upper end of the diameter-enlarging member 26 of the anchor 24 is retracted into the recess 23A of the housing 23. The diameter-enlarging portion 26A of the diameter-enlarging member 26 enlarges the diameter of the lower portion of the sleeve 25 of the anchor 24, and the anchor 24 is firmly fixed to the small-diameter hole 14B (see FIG. Figure 6C ).

[0056] In addition, it should be noted that the present invention is not limited to the above-described embodiment and its modified examples, and various changes and improvements can be made within the scope of the matters described in the claims of the present application.

Claims

1. A magnetic marker which is embedded in a road by being struck on its upper surface and is configured to be detected by a magnetic sensor installed in a vehicle, characterized in that: The magnetic marker has: a housing that houses the magnet and a protective material covering the magnet and is formed into a cylindrical shape with a closed bottom and an open top; and An anchor is provided to protrude downward from the housing and is configured to expand in diameter when buried in the road. The anchoring member comprises: a sleeve, an upper end portion of which is fixed to the housing; and an expanding member configured to be loosely fitted in the sleeve and movable in the axial direction. A cutout is formed in the lower portion of the sleeve along the axial direction. The lower portion of the diameter expander has a diameter expansion portion, which protrudes from the sleeve and expands in diameter downward. The diameter-expanding member is configured to be buried in the road by the magnetic marker being driven in and pushed upward, thereby expanding the diameter of the lower portion of the sleeve. The bottom surface of the housing is provided with a recessed portion with a downward opening, and the recessed portion accommodates the upper end of the diameter expander when the upper end of the diameter expander rises in the sleeve. The protective material is in liquid form before being poured into the shell, and solidifies into a solid form after being poured into the shell, thereby fixing the magnet.

2. The magnetic label according to claim 1, wherein The diameter of the housing is the same as the diameter of the anchor.

3. A magnetic marker embedding jig configured to embed the magnetic marker according to claim 1 or 2 in the road, characterized in that: The embedding fixture of the magnetic marker comprises: a base configured to be disposed around the magnetic marker inserted into a hole provided in a pavement of the road and to accommodate the magnetic marker within an inner diameter thereof; as well as A pusher has a diameter larger than an outer diameter of the housing and is configured to be inserted into an inner diameter of the base.

4. A method for burying a magnetic marker, comprising burying the magnetic marker according to claim 1 in the road, characterized in that: In the embedding method, Punching holes in the road, Punching the magnetic label into the hole, The diameter of the anchor is expanded by the upward movement of the diameter expansion member relative to the sleeve.

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