Road surface condition testing machine, road surface condition testing method

Abstract

This invention provides a road surface condition testing machine and road surface condition testing method that can evaluate aggregate scattering resistance while reflecting actual driving conditions. [Solution] The system comprises a frame 3 placed on a test road surface S, an arm 17 supported by the frame 3 and rotating in a plane parallel to the test road surface S, and a tire holder 21 supported by the arm 17. The tire holder 21 supports a tire 73, and the tire 73 is supported at an angle by the tire holder 21 so that its side surface 73B is in contact with the test road surface S and it rotates.

Description

Technical Field

[0001] The present invention relates to a road surface property tester and a road surface property test method.

Background Art

[0002] Generally, for road surfaces such as those of auto race tracks, construction is carried out using a porous asphalt mixture. When constructing a road surface, in advance in a laboratory, an indoor mix design of the porous asphalt mixture and a road surface property test are carried out. The road surface property test is performed by the Cantabro test. The Cantabro test is a test for evaluating the aggregate scattering resistance of an asphalt mixture. A test specimen for the test is placed in a Los Angeles tester, the drum is rotated a certain number of times, and the loss amount after the test is measured (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, at an auto race track or the like, with the motorcycle tilted, the side surface of the tire is brought into contact with the running road surface, and the running road surface of the auto race track is traveled and circled at high speed. In a conventional test for evaluating the aggregate scattering resistance using a Los Angeles tester, there is a problem that such an actual running state is not reflected. An object of the present invention is to provide a road surface property tester and a road surface property test method capable of evaluating the aggregate scattering resistance in a state reflecting the actual running state.

Means for Solving the Problems

[0005] One aspect of the apparatus of the present invention comprises a frame placed on a test road surface, an arm supported by the frame and rotating in a plane parallel to the test road surface, and a tire holder supported by the arm, wherein the tire holder supports a tire, and the tire is supported at an angle by the tire holder so that its side surface is in contact with the test road surface and it rotates.

[0006] One aspect of the method of the present invention comprises the steps of: constructing a test road surface; placing a road surface condition testing machine on the test road surface; rotating a tire supported at an angle to the road surface condition testing machine with its side surface in contact with the test road surface; and checking the amount of aggregate scattered from the test road surface and evaluating the aggregate scattering resistance and road surface condition. [Effects of the Invention]

[0007] According to the present invention, aggregate scattering resistance can be evaluated while reflecting actual driving conditions. [Brief explanation of the drawing]

[0008] [Figure 1] A schematic side view showing a road surface condition testing machine. [Figure 2] This is also a floor plan. [Figure 3] Flowchart for road surface condition testing. [Modes for carrying out the invention]

[0009] [1. Configuration of Embodiment 1] Figure 1 is a schematic side view of the road surface condition testing machine 1, and Figure 2 is a plan view of the same. In Figures 1 and 2, the symbol S indicates the test road surface. The test surface S is constructed at a test site, for example, for construction testing of a track at an auto racing track. The test surface S is constructed using a porous asphalt mixture, and polymer-modified asphalt type H is used as the binder. Note that the test surface S is not limited to a test track at an auto racing track.

[0010] As shown in Figures 1 and 2, the road surface condition testing machine 1 includes a frame-shaped stand 3 that is placed on the test road surface S. The stand 3 is formed by welding steel materials into a frame shape, and a motor 9 with a reduction gear is mounted on the top of the stand 3. A circular guide fence 91 is arranged around the stand 3. The guide fence 91 is installed in two stages, upper and lower, and includes an upper guide fence 91A and a lower guide fence 91B.

[0011] The frame 3 comprises a pair of frames 4 and 5 extending parallel to the test surface S. Flat connecting plates 10 are attached to the frames 4 and 5, and a rotating shaft 13 is supported by the connecting plates 10. The rotating shaft 13 rotates about an axis extending in the vertical direction. A large-diameter gear 14 is attached to the lower end of the rotating shaft 13. The large-diameter gear 14 is connected to the small-diameter gear 16 via a power transmission chain 15. The small-diameter gear 16 is connected to the output shaft 9A of the motor 9 with a reduction gear. The motor 9 with a reduction gear is connected to the commercial power supply.

[0012] When the motor 9 with a reduction gear is driven, the rotating shaft 13 rotates clockwise (in the direction of arrow B) via the small-diameter gear 16, the power transmission chain 15, and the large-diameter gear 14. Alternatively, an engine may be installed instead of the motor 9 with a reduction gear, and the rotating shaft 13 may be rotated by the engine.

[0013] The lower end of the rotating shaft 13 is rotatably supported by a bearing 50, which is supported by a support frame 51. The support frame 51 is fixed to the frame 3 and extends parallel to a pair of frames 4 and 5.

[0014] An arm 17 is attached to the lower end of the rotating shaft 13. The arm 17 extends parallel to the test road surface S. A tire holder 21 is connected to the free end 17A of the arm 17 via a tire angle adjustment mechanism 53.

[0015] The tire angle adjustment mechanism 53 is fixed to the free end 17A of the arm 17 and includes a fixed piece 55 that extends vertically and a cylindrical body 56 that is connected to the lower end of the fixed piece 55 and extends parallel to the arm 17. A slide body 57 fits on the inner circumference of the cylindrical body 56. The fixed piece 55 is swingably supported in the direction Y on a shaft 17B inserted through the free end 17A.

[0016] A tire holder 21 is connected to the tip of the slide body 57 via a link mechanism 60. The link mechanism 60 connects between the tip of the slide body 57 and a bracket 61 of the tire holder 21. A connecting piece 62 is fixed to the bracket 61, and the connecting piece 62 and the tip of the slide body 57 are pin-connected by a pin 63. A support piece 65 is fixed to the bracket 61, a protruding piece 66 is fixed to the lower part of the cylindrical body 56, and the protruding piece 66 and the support piece 65 are connected by a telescopic connecting body 67.

[0017] A pushing body 70 is connected to the rear end of the slide body 57. When the pushing body 70 is pushed, the slide body 57 protrudes, the connecting body 67 contracts by the link mechanism 60, and the tire holder 21 rises. When the pushing body 70 is pulled, the slide body 57 retreats, the connecting body 67 extends by the link mechanism 60, and the tire holder 21 lies down. With these mechanisms, the inclination of the tire holder 21 can be freely changed.

[0018] A wheel 72 is supported on the tire holder 21 by an axle 71, and a tire 73 is mounted on the wheel 72.

[0019] In Embodiment 1, when the rotating shaft 13 rotates in the direction of arrow B, the tire 73 rotates in the direction of arrow B in a plane parallel to the test road surface S via the arm 17. The tire 73 revolves around the rotating shaft 13 along a revolution orbit K (see FIG. 1) and rotates around the axle 71 along a rotation orbit J (see FIG. 1).

[0020] Tire 73 is a tire for an auto racing motorcycle and has a substantially triangular cross section. The tire for an auto racing motorcycle has not only high running performance but also high grip force, enabling stable running while preventing skidding such as slipping. However, tire 73 is not limited to the tire for an auto racing motorcycle.

[0021] Tire 73 includes a side surface 73B located on the inner side and a side surface 73C located on the outer side in the rotational direction of arm 17. Tire 73 is obliquely supported so that the inner side surface 73B contacts the test road surface S.

[0022] Although not shown in the figure, a balance weight 90 may be installed on the rotating part. The tire contact pressure can be adjusted by weight adjustment. Balance weight 90 is a single-pipe weight. Balance weight 90 is provided by hooking it on the pressing body 70. By lifting tire 73 around shaft 17B due to the load of balance weight 90, the contact load, that is, the tire contact pressure is adjusted.

[0023] For test road surface S, a porous asphalt mixture containing asphalt and coarse aggregate is used. Test road surface S has an uneven shape, and the coarse aggregate is exposed on the convex part. In Embodiment 1, with tire 73 having its inner side surface 73B contacting test road surface S, as tire 73 rotates on test road surface S, the aggregate on the convex part scatters. In Embodiment 1, it is only necessary to visually confirm the scattering of the aggregate, and the aggregate scattering resistance can be easily evaluated in a state reflecting the actual running state.

[0024] In Embodiment 1, a tire holder 21 is connected to the free end 17A of arm 17 via a tire angle adjustment mechanism 53. Thereby, the angles of tire holder 21 and tire 73 can be adjusted, and the lateral slip of the tire is adjusted.

[0025] At auto racing tracks, auto racing motorcycles are tilted, with the sides of the tires in contact with the track surface, and they travel at high speeds and complete laps. Embodiment 1 allows for testing that more accurately reflects actual driving conditions.

[0026] [2. Challenges and Solutions] The inventors discovered the following problems when conducting road surface condition tests. (1-1) If the load on the road surface condition testing machine 1 is too large, a large amount of aggregate will be scattered due to damage to the test road surface S, making accurate evaluation impossible. (2-1) If the rotation speed of the road surface condition testing machine 1 is too slow, the tearing of the tire cannot be accurately evaluated. (3-1) Accurate evaluation is not possible unless conditions such as road surface temperature, tire temperature, and sunlight exposure are standardized. (4-1) The weight of the tires cannot be measured accurately (for example, the weight of the tires may increase when it should decrease).

[0027] The following measures were taken to address these issues. (1-2) A balance weight was installed on the rotating part, and the installation load was adjusted to approximately 15 kg. With this setup, the aggregate scattering resistance could be accurately evaluated without being affected by the load of the road surface condition testing machine 1. (2-2) The rotation speed of the road surface condition testing machine 1 was increased to approximately 16 km / h. This allowed for accurate evaluation of tire tearing. (3-2) Before measurement, the road surface was covered with a blue sheet to suppress the rise in road surface temperature due to sunlight, and during rapid determination, the road surface condition testing machine 1 was covered with a blue sheet to standardize the sunlight conditions. Since the temperature of the tires rises due to friction, this was addressed by covering them with the blue sheet mentioned above. (4-2) For tire measurements, rubber was removed from every detail using a scraper, and scattered rubber material was also collected and measured.

[0028] [3. Road surface condition test] Figure 3 is a flowchart showing the procedure for road surface condition testing. In Step S1, a test road surface (hereinafter referred to as the first test road surface) S is constructed at the test site using porous asphalt pavement according to a predetermined mix design. Porous asphalt pavement is a type of pavement that uses porous asphalt mixture in the surface layer or surface / base layer, and has a high void ratio, allowing rainwater to quickly penetrate beneath the road surface and reducing noise generated between the tires and the road surface. Step S1 may include a step in which, after constructing the first test road surface S, the first test road surface S is covered with a blue sheet (not shown in the illustration). This is to suppress the rise in road surface temperature due to sunlight.

[0029] In step S2, although not shown in the diagram, the road surface condition testing machine 1 is placed on the first test road surface S using, for example, a forklift. If the first test road surface S was covered with a blue sheet in step S1, the blue sheet is removed and then the road surface condition testing machine 1 is placed on the first test road surface S.

[0030] In step S3, the motor 9 with a reduction gear is driven. Step S3 may include a step in which the road surface condition testing machine 1 is covered with a blue sheet (not shown in the illustration) to standardize the sunlight conditions. When the motor 9 with a reduction gear is driven, the rotating shaft 13 rotates via the small-diameter gear 16, the power transmission chain 15, and the large-diameter gear 14. The rotational speed of the rotating shaft 13 can be increased to 16 km / h or more by changing the pulley or the like. Step S3 may include a step of increasing the rotational speed of the rotating shaft 13 to 16 km / h or more.

[0031] As the rotation axis 13 rotates, the arm 17 rotates in a plane parallel to the first test road surface S, and the tire holder 21, which is supported at the free end 17A of the arm 17 via the tire angle adjustment mechanism 53, rotates in conjunction with the arm 17. As a result, the tire 73 supported by the tire holder 21 rotates around the axle 71. In other words, when the motor 9 with a reduction gear is driven and the rotating shaft 13 rotates, the tire 73, which is supported at an angle by the road surface condition testing machine 1, revolves around the rotating shaft 13 via the arm 17, and the tire 73 rotates on its axis around the axle 71 with its side surface 73B in contact with the test road surface S.

[0032] Numerous aggregates are exposed on the surface of the first test road surface S, and when the tire 73 is rolled over it, the aggregates are scattered into the surrounding area due to friction with the tire 73.

[0033] In step S4, the aggregate scattering resistance and road surface condition of the first test road surface S are evaluated as "good (Yes)" or "bad (No)" by visually checking the condition of the aggregate scattering from the first test road surface S at this time.

[0034] If the aggregate scattering resistance is "good," in step S5, the actual auto race track is constructed according to the mix design of the first test track surface S. Test surface S was constructed using a porous asphalt mixture, with polymer-modified asphalt type H used as the binder.

[0035] If the aggregate scattering resistance is "poor," in step S6, the mix design of the first test surface S is revised, and another test surface (hereinafter referred to as the second test surface) S is constructed with the revised new mix design. Then, in step S2, the road surface condition testing machine 1 is placed again on the second test road surface S, and steps S3 to S4 are repeated. If the evaluation of the second test surface S is "poor" in step S4, then in step S6, the compound design of the second test surface S is revised, and a different test surface (third test surface) S is constructed with the revised new compound design. Note that the road surface evaluation for the third test road surface S and subsequent tests is carried out using the same steps as the evaluation for the second test road surface S, so the explanation will be omitted.

[0036] According to Embodiment 1, by simply placing the road surface condition testing machine 1 on the first test road surface S and operating the road surface condition testing machine 1 to rotate the tire 73, the aggregate scattering resistance and road surface condition can be easily evaluated by visually checking the state of aggregate scattering from the first test road surface S.

[0037] If the aggregate scattering resistance is "poor," the mix design of the first test road surface S can be revised, a second test road surface S can be constructed with the new mix design, the road surface condition testing machine 1 can be placed on the second test road surface S, and the tires 73 can be driven. In this way, the road surface condition of the second test road surface S can be easily evaluated by visually checking the state of the aggregate scattering from the second test road surface S with the new mix design.

[0038] According to Embodiment 1, aggregate scattering resistance and road surface characteristics can be evaluated without using a Los Angeles testing machine or the like, and road surface characteristic tests different from the Cantablo test can be performed, enabling tests that better reflect actual driving conditions.

[0039] According to Embodiment 1, the method includes: step S1 of constructing a first test road surface S; step S2 of placing a road surface condition testing machine on the first test road surface S; step S3 of rotating a tire 73, which is supported diagonally with respect to the road surface condition testing machine 1, with the inner side surface 73B of the tire 73 in contact with the first test road surface S; and step S4 of checking the amount of aggregate scattered from the first test road surface S and evaluating the aggregate scattering resistance and road surface condition. According to this method, the aggregate scattering resistance and road surface properties can be easily evaluated by visually checking the amount of aggregate scattered from the first test road surface S.

[0040] If the aggregate scattering resistance is "poor," in step S6, the mix design of the first test road surface S is reviewed, and a second test road surface S is constructed with the new mix design. In step S2, the road surface condition testing machine 1 is placed on the second test road surface S, the tires 73 are driven, and steps S3 to S4 are repeated. This allows for easy evaluation of the road surface condition of the second test road surface S by visually checking the state of aggregate scattering from the second test road surface S with the new mix design.

[0041] [3. Embodiment 2] Although not shown in the figures, Embodiment 2 differs from Embodiment 1 in that the lower end of the rotating shaft has multiple arms instead of one. For the sake of clarity, the same parts as in Embodiment 1 will be denoted by the same reference numerals below. Multiple arms 17 are attached radially to the lower end of the rotation axis 13, and a tire holder 21 is connected to the free end 17A of each arm 17 via a tire angle adjustment mechanism 53. A tire 73 is supported by each tire holder 21. The configuration of the rotating shaft 13, arm 17, tire angle adjustment mechanism 53, tire holder 21, and tire 73 is substantially the same as in Embodiment 1.

[0042] According to Embodiment 2, when the rotating shaft 13 is rotated, the multiple tires 73 revolve around the rotating shaft 13 via their respective arms 17, and are supported by the axle 71, causing the multiple tires 73 to rotate on the axle 71.

[0043] In Embodiment 2, the aggregate scattering resistance can be easily evaluated simply by visually checking the state of the aggregate scattered from the test road surface S. Furthermore, in Embodiment 2, compared to Embodiment 1, multiple tires roll along the trajectory of a single tire 73, allowing for rapid confirmation of aggregate scattering resistance.

[0044] Although the present invention has been described above based on one embodiment, the present invention is not limited thereto, and various modifications are possible, such as the form of the frame 3.

[0045] The road surface condition testing machine 1 of this embodiment is suitable for testing the properties of a motorcycle tire 73 with a roughly triangular cross-section, but it is not limited to this and can be applied to testing the properties of any tire. [Explanation of Symbols]

[0046] 1. Road surface condition testing machine 3. Stand 4, 5 frames 9. Motor with reduction gear 13 Rotation axis 17 Arms 21 Tire Holder 53 Tire angle adjustment mechanism 55 Fixed piece 56 Cylinder 57 Slide body 60 Link Mechanism 73 Tires S Test surface

Claims

1. A platform placed on the test track surface, An arm supported by the aforementioned frame and rotating in a plane parallel to the test surface, A tire holder supported by the aforementioned arm, Equipped with, US tire holders support tires, The tire is supported at an angle by the tire holder so that its side surface is in contact with the test road surface and it can rotate. Road surface condition testing machine.

2. The tire holder is supported by the arm so as to be able to adjust its tilt. The road surface condition testing machine according to claim 1.

3. A tire tilt adjustment mechanism is provided between the tire holder and the arm. The road surface condition testing machine according to claim 2.

4. The aforementioned tire is a tire for an auto racing motorcycle, and the tire, which has a roughly triangular cross-section, is rotated with its side surface in contact with the test road surface. The road surface condition testing machine according to claim 1.

5. Steps for constructing the test road surface, The steps include: placing a road surface condition testing machine on the aforementioned test road surface; The steps include: rotating a tire that is supported at an angle to the road surface condition testing machine with the side surface of the tire in contact with the test road surface; The steps include confirming the amount of aggregate scattered from the aforementioned test road surface and evaluating the aggregate scattering resistance and road surface properties, Equipped with Road surface condition testing method.

6. The aforementioned step of rotating is This includes a step of adjusting the installation load with a balance weight installed on the rotating part. The road surface condition test method according to claim 5.

7. The aforementioned step of rotating is This includes a step to increase the rotational speed to 16 km / h or more. The road surface condition test method according to claim 5.

8. Before the aforementioned step of placing, The steps include covering the aforementioned test surface with a blue tarp, During the aforementioned rotation step, The steps include covering the road surface condition testing machine with a blue tarp, including, The road surface condition test method according to claim 5.

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