Load movement test device

Abstract

To provide a load movement test device that is compact, low-cost, and applicable even for preliminary tests before a main test.SOLUTION: A load movement test device 1 for performing quality tests of specimens by moving a test wheel with traveling load application means and applying a load by the test wheel to the specimen on a paved road surface, comprises: a rotating body 14 that rotates about an axis perpendicular to the road surface of the specimen T, an arm 15 that extends in a direction parallel to the road surface from the rotating body 14, a test wheel W that is rotatably attached to the arm 15, a drive body Wa that rotationally drives the test wheel W, and load application means 13 that relatively presses the test wheel W against the road surface.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a load transfer test device for performing a quality test on a test specimen by moving a test wheel with a traveling load applying means and applying a load from the test wheel to the test specimen of a paved road surface. [Background technology]

[0002] Load transfer test devices are known that use simulation tests to grasp and evaluate the state of wear, deformation, and damage of road pavement surfaces caused by the load (traveling wheel load) from the wheels of a vehicle traveling on a paved road, as well as the prediction of such wear, deformation, and damage (see, for example, Patent Documents 1 and 2). These conventional load transfer test devices are designed to inspect whether a test specimen meets predetermined standards by placing a test wheel on the surface of a test specimen which resembles a road surface, pressing the test wheel against the surface of the test specimen (road surface) with a load corresponding to the vehicle weight, and moving the test wheel back and forth on the road surface while applying a rotational driving force to the test wheel, and then observing the wear, deformation, and damage of the road surface after a certain period of time.

[0003] However, the above-mentioned conventional load transfer test apparatus has the following problems. (1) The test wheel moves linearly in the front-rear direction while being guided by a guide rail arranged parallel to the road surface above the test piece, but the guide rail protrudes significantly from both ends of the test piece, which causes a problem of the device becoming large. In addition, since the test wheel is subjected to a load equivalent to the weight of an actual vehicle, the guide rail is required to have high rigidity to withstand this load, which also causes a problem of the device becoming large and heavy. (2) As described above, conventional equipment is large and expensive, and requires a large installation area, which results in high testing costs. Therefore, if the test results do not meet the standards, the test specimen must be remade and the test must be repeated, which further increases the cost burden on the business operator. In particular, research and development of new pavement surfaces is inevitably subject to failure, and there is a problem in that repeated testing of newly developed pavement surface specimens using conventional load transfer test equipment would be extremely costly. (3) Furthermore, conventional equipment can only test one specimen per device, so if multiple types of specimens must be tested, the tester must wait until one specimen finishes testing, which results in a long test time. This problem can be solved by preparing multiple devices, but this increases the equipment costs, which in turn increases the test costs. (4) In addition, with conventional testing equipment, tests are conducted by moving the test wheels back and forth. However, on an actual paved road surface, the wheels only move in one direction. This means that a test in which the wheels repeatedly move forward and backward over a short distance is dissociated from the actual vehicle movement, making it difficult to obtain accurate test results that correspond to the actual vehicle movement. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-214102 A (see FIG. 5) [Patent Document 2] JP 2001-59805 A (see FIG. 1) DISCLOSURE OF THEINVENTION [Problem to be solved by the invention]

[0005] The present invention has been made in consideration of the above problems (1) to (4), and has an object to provide a load transfer test device that can solve all of these problems at once. [Means for solving the problem]

[0006] In order to solve the above problems, the load transfer test apparatus described in claim 1 is a load transfer test apparatus for moving a test wheel by a running loading means and applying a load from the test wheel to a specimen of a paved road surface to perform a quality test of the specimen, and is configured to include a rotating body that rotates around an axis perpendicular to the road surface of the specimen, the test wheel that is rotatably supported on this rotating body, a driving body that rotates the test wheel relative to the specimen, and a load applying means that presses the test wheel relative to the road surface. In addition, the above term "relatively" means applying a driving force for rotation or a load for pressing to either or both of the test wheel and the specimen, and is a concept that includes, for example, a case in which the load application means applies a load to the test wheel to press it against the road surface, a case in which a load is applied to the specimen to press the road surface against the test wheel, and a case in which a load is applied to both the test wheel and the specimen to press the test wheel and the road surface against each other.

[0007] As described in claim 2, a plurality of the test specimens may be arranged on the moving path of the test wheel. In this case, as described in claim 3, the height of the road surface of at least a part of each of the plurality of test specimens may be made different from that of the other test specimens. By making the road surface height different in this manner, even if the load applying means is a single driving body such as a cylinder, the load acting between the test wheel and the test specimen can be made different for each test specimen, and tests with different test loads can be performed simultaneously on the plurality of test specimens.

[0008] In the testing device having the above configuration, if there is a space in front of or behind the specimen, the load of the test wheel will suddenly disappear in the space, which may cause noise, breakdowns, and shortened life of the device. Therefore, as described in claim 4, a guide may be provided that is arranged adjacent to the specimen and on the moving path of the test wheel, has a guide surface on which the test wheel rolls, and transfers the test wheel from the guide surface to the road surface while rolling. In this case, by making the guide surface continuous with the road surface of the test specimen, it is possible to eliminate a sudden change in load when the test wheel is transferred from the guide surface to the road surface of the test specimen. By providing a slight step between the guide surface and the road surface, it becomes possible to perform road surface tests on parts with steps, such as bridge joints.

[0009] As described in claim 5, the guide may be another of the test specimens. In this way, by moving the test wheel while always applying a constant load, it becomes possible to test more test specimens continuously and simultaneously.

[0010] As described in claim 6, a plurality of the test wheels may be supported by the rotating body. For example, a plurality of arms may be provided extending radially from the rotating body, and the test wheels may be rotatably attached to each of the arms. In this case, the plurality of test wheels may be arranged corresponding to the plurality of test specimens. In this way, the test time can be further reduced.

[0011] The load applying means may apply a load to each of the test wheels via the rotating body by applying a load with a cylinder, weight, or the like to the rotating body, or may apply a pressing force to the specimen with a cylinder or the like, thereby applying a load to the test wheel. Furthermore, as described in claim 7, the load applying means may be provided for each of the test wheels. In this way, different loads can be applied to each of the test wheels, making it possible to perform tests according to the usage conditions of an actual road surface on which vehicles of different weights pass, for example. Effect of the Invention

[0012] According to the present invention, the test wheel rotates in one direction while testing the specimen, so that the test can be performed according to the actual running of the vehicle. In addition, by appropriately switching the driving direction of the driving body and moving the test wheel in the opposite direction, it is possible to perform the test not only for forward running but also for reverse running. Furthermore, by providing multiple test wheels, it is possible to pass the rotating wheels over a single test specimen one after another at short intervals, enabling the test to be completed in a shorter time than with conventional linear motion type testing equipment.

[0013] Furthermore, by making the running direction of the test wheels the rotational direction instead of the linear direction, highly rigid guide rails that protrude significantly from both ends of the test specimen are no longer necessary, making it possible to make the test equipment smaller and lighter, and reducing test costs. This makes it easier to conduct preliminary tests before main tests using conventional test equipment, and by preventing non-compliance with standards in advance, it is possible to reduce test costs and test times. Furthermore, multiple test pieces can be tested simultaneously, which also contributes to reducing the testing cost and time. It will also be possible to vary conditions such as load for multiple test specimens, or to apply impacts due to bumps, making it possible to conduct tests that correspond to the actual usage conditions of road surfaces. BEST MODE FOR CARRYING OUT THEINVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a load transfer testing device (hereinafter referred to as a testing device) of the present invention will be described in detail with reference to the drawings. [First embodiment] FIG. 1 shows a first embodiment of a testing device according to the present invention, and is a schematic plan view illustrating the configuration thereof. FIG. 2 is a schematic front view illustrating the configuration thereof. The testing apparatus 1 of this embodiment has a base 11 on which the test specimen T is placed, a rotating body 14 supported on the base 11 so as to be freely rotatable about a vertical axis and so as to be freely raised and lowered along the vertical axis, and a number of arms 15 (four arms at 90 degree intervals in this embodiment) extending radially from the side surface of the rotating body 14 at equal angular intervals.

[0015] A cylinder 13 is provided on the base 11 as a load applying means, and a rotor 14 is attached to the tip of a piston rod 13a that moves up and down in the vertical direction by driving the cylinder 13. Each of the four arms 15 of the rotor 14 extends in a horizontal direction parallel to the surface (road surface) of the test specimen T, and a test wheel W that contacts the surface (road surface) of the test specimen T is attached to the tip of the arm 15. A driver Wa such as a motor that rotates the test wheel W forward and backward is provided on the arm 15. The driver Wa may be provided on one or two of the four test wheels W, or the driver Wa may be provided on all of the test wheels W. When the driver Wa is provided on more than one of the four arms 15, the drive of the driver Wa is synchronized so that the peripheral speed of each test wheel W is the same.

[0016] Four test specimens T are prepared corresponding to the four test wheels W arranged at equal intervals, and are placed and fixed at equal intervals on the base 11. The surfaces (road surfaces) of the four test specimens T are set to be located on the same plane, so that the pressing force from the test wheels W is the same. Furthermore, by varying the surface height of the test specimen T, the magnitude of the load applied by the test wheel W can be changed for each test specimen T, making it possible to conduct tests that are appropriate to the road environment in which each test specimen T is used.

[0017] The driving of the cylinder 13 and the driver Wa is controlled by commands from a control device (not shown). That is, in response to a command to start a test, the cylinder 13 is driven to retract the piston rod 13a, and the test wheel W is pressed against the road surface of the test specimen T with a preset test load via the rotor 14 and the arm 15. After this, the control device drives the driver Wa to rotate the test wheel W. As a result, the test wheel W runs in one direction on the road surface of the test specimen T along a trajectory indicated by symbol I in FIG. 1, centered on the rotation axis of the rotor 14. According to the test device of the present invention, the rotating wheels W pass one test specimen T one after another at short intervals, which is an advantage in that the test can be completed in a short time. Depending on the test conditions, it is also possible to reverse drive the driver Wa as appropriate to rotate the test wheel W in the opposite direction.

[0018] [Second embodiment] FIG. 3 is a schematic plan view illustrating the configuration of a second embodiment of a testing device according to the present invention, and FIG. 4 is a schematic front view illustrating the configuration. When four test specimens T are arranged in four directions as shown in Fig. 1, gaps are formed between adjacent test specimens T, T. A load is always applied to the test wheel W by a load application means (cylinder 13 in this embodiment) in a downward direction, that is, in a direction pressing the test wheel W against the road surface of the test specimen T. Therefore, when the test wheel W moves from the test specimen T to the gap, the load suddenly disappears, and a large load fluctuation acts on the arm 15, the rotor 14, the piston rod 13a, and the cylinder 13. This load fluctuation is a source of noise and may be a factor that reduces the life of the device and the test accuracy.

[0019] In order to solve such a problem, the shapes of the test specimens T, T may be selected so that no gap is formed between adjacent test specimens T, T. Also, as shown in the second embodiment, a guide C may be provided in the gap between adjacent test specimens T, T. In this way, when the test wheel W moves from one test specimen T to the other adjacent test specimen T, a sudden load change acting on the arm 15, etc. can be suppressed, and the test wheel W can move smoothly between the adjacent test specimens T, T. In order to enable smooth movement between specimens T and T and to eliminate sudden load changes, the surface of guide C should be made the same height as the surfaces of the adjacent specimens T and T.

[0020] As described in the previous embodiment, if the height of the surface of one specimen T is to be different from the height of other specimens T, the surface of the guide C can be made into an inclined surface that continues from the surface (road surface) of one specimen T at a different height to the surface (road surface) of the other specimen T. In addition, by providing a step between the surface of the guide C and the test specimen T, it is possible to reproduce the step of a road joint on a bridge or the like, and to test the test specimen T having such a step. In this way, the test device of the present invention has the advantage that a variety of tests can be carried out in a short time. Furthermore, the guide C can be another specimen T. In this way, it becomes possible to simultaneously test even more specimens T. In this embodiment, it becomes possible to simultaneously test a maximum of eight specimens T.

[0021] [Third embodiment] FIG. 5 is a schematic plan view illustrating the configuration of a third embodiment of a testing device according to the present invention, and FIG. 6 is a schematic front view illustrating the configuration. The test apparatus 1 shown in Figures 5 and 6 is based on the test apparatus 1 of the second embodiment, but the same parts and members as those of the test apparatus of the second embodiment are given the same symbols and detailed descriptions are omitted. In the first and second embodiments described above, the cylinder 13 is used as the load applying means, and the load is applied to the four test wheels W via the rotor 14 and the arm 15. The advantage of such a load applying means (cylinder 13) is that a single cylinder 13 can apply a load to the four test wheels W simultaneously, If the road surface heights of the four test specimens T are the same, a uniform load can be applied to the four test wheels W.

[0022] The difference between this third embodiment and the first and second embodiments is that each of the four test wheels W is provided with a weight 13' as a load-applying means, and each test wheel W is pressed against the road surface of the test specimen T by this weight 13'. 5, the weight 13' is shown by hatching, and is supported by the arm 15. For example, a frame surrounding the test wheel W within a range not contacting the test wheel W, the specimen T, and the guide C may be attached to the arm 15, and the weight 13' may be placed on the frame. In this way, it becomes easy to apply different loads to each of the four test wheels W. By making the loads of the test wheels W that pass over one specimen T different, it becomes possible to perform a road load test that is close to an actual road surface on which vehicles of different weights repeatedly run.

[0023] Although the preferred embodiments of the present invention have been described, the present invention is not limited to the above description. For example, in the first to third embodiments, the number of test pieces is four, but it is also possible to set the number to four or more or less than four. In the second or third embodiment, it is possible to perform testing on four or more specimens (up to eight specimens in the illustrated example) by arranging a specimen T instead of the guide C. Furthermore, in the first to third embodiments, the specimen T may be used as the guide C.

[0024] Furthermore, in the first and second embodiments, a driver (cylinder 13 and piston rod 13a) that presses the test wheel W against the road surface of the specimen T is provided on the base 11, and a load is applied to the test wheel W via the rotating body 14 and the arm 15. However, a driver such as a cylinder may be provided on the base 11 or the specimen T side, and a load may be applied to the test wheel W by lifting the base 11 or the specimen T. In addition, in the above embodiment, four arms 15 are radially arranged on the rotating body 14, and the test wheels W are rotatably attached to the tips of the arms 15. However, if the rotating body is ring-shaped, for example, it will be possible to directly support the test wheels on the rotating body in a rotatable manner, and therefore the arms 15 are not necessarily required for such a rotating body. [Industrial Applicability]

[0025] The present invention can be widely applied to quality testing of specimens, and by using it in preliminary testing prior to quality testing, it is possible to prevent the need to retest quality testing, which is costly. [Brief description of the drawings]

[0026] [Figure 1] 1 is a schematic plan view illustrating a configuration of a test device according to a first embodiment of the present invention; [Diagram 2] 1 is a schematic front view illustrating a configuration of a testing device according to a first embodiment of the present invention. FIG. [Diagram 3] FIG. 11 is a schematic plan view illustrating the configuration of a test device according to a second embodiment of the present invention. [Figure 4] FIG. 4 is a schematic front view illustrating the configuration of a test device according to a second embodiment of the present invention. [Diagram 5] FIG. 11 is a schematic plan view illustrating the configuration of a test device according to a third embodiment of the present invention. [Figure 6] FIG. 11 is a schematic front view illustrating the configuration of a test device according to a third embodiment of the present invention. [Explanation of symbols]

[0027] 1: Load transfer test device (test device) 11: Bass 13: Cylinder 13a: Piston rod 13′: Weight 14: Rotating body 15: Arm C: Guide T: Specimen W: Test wheel Wa: Drive body

Claims

1. A load transfer test device for performing a quality test of a pavement surface specimen by moving a test wheel using a traveling load applying means and applying a load from the test wheel to the pavement surface specimen, A rotating body that rotates around an axis perpendicular to the road surface of the test specimen; The test wheel is rotatably supported on the rotating body; and A drive unit that rotates the test wheel relative to the specimen; A load applying means for pressing the test wheel relatively against the road surface; A load transfer test device comprising:

2. 2. The load transfer test device according to claim 1, wherein a plurality of the test specimens are arranged on the moving path of the test wheel.

3. 3. The load transfer test apparatus according to claim 2, wherein the height of the road surface of at least a part of each of the plurality of pre-test specimens is made different from that of the other pre-test specimens.

4. 3. A load transfer test device as described in claim 1 or 2, characterized in that it is arranged adjacent to the specimen on the movement path of the test wheel, has a guide surface on which the test wheel rolls, and is provided with a guide along which the test wheel is transferred from the guide surface to the road surface while rolling.

5. 5. The load transfer test apparatus of claim 4, wherein said guide is another of said test specimens.

6. 4. The load transfer test device according to claim 1, wherein a plurality of the test wheels are supported on the rotating body.

7. 7. The load transfer test device according to claim 6, wherein the load applying means is provided for each of the test wheels.

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