Tire testing device

Abstract

One embodiment of the tire testing apparatus of the present invention includes: a road surface; and a wheel carrier that rotatably holds a test tire mounted thereon, and is capable of traveling along the road surface when the test tire is in contact with the road surface. The wheel carrier includes: an axle portion that rotatably supports the test tire; and an alignment portion that adjusts the wheel alignment of the test tire by changing the direction of the axle portion. The alignment portion includes a load adjustment portion that adjusts the load applied to the test tire by changing the height of the axle portion. The load adjustment portion includes: a first movable frame that is vertically movable; a linear guide that guides the vertical movement of the first movable frame; and a first drive unit that drives the first movable frame vertically.

Description

[Technical Field]

[0001] This invention relates to a tire testing device. [Previous Technology]

[0002] Tests for evaluating tire performance include: road tests, which involve mounting test tires, for example, on the rims of a dedicated test vehicle and driving them on actual road surfaces; and indoor tests (bench tests) conducted using indoor testing equipment. Bench tests have better repeatability than road tests.

[0003] Japanese Patent Application Publication No. 2015-72215 (Patent Document 1) describes an example of a testing device used for testing tires on a test bench. The testing device described in Patent Document 1 includes a rotating drum with a simulated road surface on its outer circumference. When the test tire is in contact with the simulated road surface, the test tire and the drum are rotated to perform the test. [Summary of the Invention]

[0004] (The problem that the invention is intended to solve)

[0005] Tire performance is affected by road surface conditions, so it is necessary to evaluate road surfaces under various conditions. However, the testing equipment used in the past for bench testing made it difficult to test on roads covered by rain, snow, and gravel because it simulated high-speed driving on the road surface during testing.

[0006] This invention was made in view of the above circumstances, and its object is to provide a tire testing device capable of performing bench tests under various road surface conditions. (Means for solving the problem)

[0007] One embodiment of the present invention provides a tire testing device comprising: a road surface; and a wheel frame rotatably holding a test wheel on which a test tire is mounted, and capable of traveling along the road surface while the test tire is in contact with the road surface; the wheel frame comprises: an axle portion rotatably supporting the test wheel; and an alignment portion, which adjusts the wheel alignment of the test wheel by changing the direction of the axle portion; the alignment portion comprises a load adjustment portion, which adjusts the load applied to the test wheel by changing the height of the axle portion; the load adjustment portion comprises: a first movable frame movably supporting the test wheel; a linear guide rail guiding the first movable frame to move up and down; and a first drive unit driving the first movable frame up and down.

[0008] The above-mentioned tire testing device may also be configured as a linear guide rail comprising: a track; and a first traveling part, which can travel on the track; either the track or the first traveling part is fixed to a first movable frame.

[0009] In the above-mentioned tire testing device, the wheel frame may also be configured to have a main frame, which is a small house-shaped alignment mechanism support that houses the alignment part.

[0010] In the above-mentioned tire testing device, the other side of the track and the first traveling part may also be fixed to the alignment mechanism support.

[0011] The above-mentioned tire testing device may also be configured with an alignment part having a camber adjustment part, which can adjust the camber angle of the test wheel. The camber adjustment part includes: a second movable frame, which is rotatably supported around an Eϕ axis parallel to the driving direction of the wheel frame; and a ϕ drive unit, which drives the second movable frame to rotate around the Eϕ axis.

[0012] The above-mentioned tire testing device may also include an outward tilt adjustment part comprising: a cylindrical first pivot, which is coaxially arranged with the Eϕ axis; and a first bearing, which rotatably supports the first pivot; either the first pivot or the first bearing is fixed to a second movable frame.

[0013] In the above-mentioned tire testing device, the other part of the first pivot and the first bearing can also be fixed to the first movable frame.

[0014] In the above-mentioned tire testing device, the camber adjustment part may also be equipped with a curved guide rail, which guides the rotation of the second movable frame.

[0015] The above-mentioned tire testing device may also be configured with a curved guide rail comprising: an arc-shaped curved track, which is concentrically arranged with the Eϕ axis; and a second traveling part, which can travel on the track; either the curved track or the second traveling part is fixed to the second movable frame.

[0016] The above-mentioned tire testing device may also be configured with an alignment part having a slip angle adjustment part, which can adjust the slip angle of the test wheel. The slip angle adjustment part includes: a third movable frame, which is rotatably supported around an Eθ axis that is orthogonal to the Eλ axis and Eϕ axis of the rotation axis of the test wheel; and an θ drive unit, which is driven to rotate around the Eθ axis of the third movable frame.

[0017] The above-mentioned tire testing device may also include a slip angle adjustment section comprising: a cylindrical second pivot, which is coaxially arranged with the Eθ axis; and a second bearing, which rotatably supports the second pivot; either the second pivot or the second bearing is fixed to a third movable frame.

[0018] The above-mentioned tire testing device may also be configured with the following components: a main shaft; a third bearing that rotatably supports the main shaft; and a wheel hub that is coaxially mounted on the front end of the main shaft and on which a test wheel is mounted.

[0019] The above-described tire testing apparatus may also include a guiding mechanism that guides the movement of the wheel frame in the travel direction. The guiding mechanism includes: a track extending in the travel direction of the wheel frame; and a mover fixed to the wheel frame and capable of traveling on the track. The mover includes: a roller rotatable on the track; and a bearing rotatably supporting the roller. The bearing is a rolling bearing with a rotating body that rotates on the circular track. The above-described tire testing apparatus may also include a mover comprising a plurality of rollers, each comprising at least one of the following: a first roller rotatable above the head of the track; a second roller rotatable below the head of the track; and a third roller rotatable to the side of the head of the track. The above-described tire testing apparatus may also include a plurality of rollers grouped into a plurality of sets, with each set of rollers arranged side-by-side in the travel direction of the wheel frame, comprising: a first roller; and at least one of a second roller and a third roller. The aforementioned tire testing apparatus may also include a moving element comprising: a frame mounted on a wheel frame; a plurality of rods supported by the frame; and bearings comprising: an inner wheel fitted with a rod; an outer wheel fitted with the inner circumferential surface of a roller; and a plurality of rotating bodies positioned between the outer circumferential surface of the inner wheel and the inner circumferential surface of the outer wheel. The aforementioned tire testing apparatus may also include a plurality of guiding mechanisms, comprising a first guiding mechanism and a second guiding mechanism with parallel tracks, wherein at least one of the second and third rollers of each of the first and second guiding mechanisms is disposed between the tracks of the first and second guiding mechanisms. The aforementioned tire testing apparatus may also include a plurality of guiding mechanisms, comprising a first guiding mechanism and a second guiding mechanism with parallel tracks, wherein the tracks of the first and second guiding mechanisms are disposed between at least one of the second and third rollers of the first guiding mechanism and at least one of the second and third rollers of the second guiding mechanism. The tire testing apparatus described above may also include a road surface, which has a road surface, at least a portion of which is composed of replaceable road surface units. The road surface may also include a base and a paving section disposed on the base, with a road surface formed on its surface; at least a portion of the paving section is composed of at least one road surface unit. The tire testing apparatus may also include a body portion comprising a base and a paving section disposed on the base, with a road surface formed on its surface; at least a portion of the body portion is composed of at least one road surface unit. The tire testing apparatus may also include a frame portion forming a groove together with the base. The tire testing apparatus may also include a simulated road surface formed by a material different from the actual road surface. The tire testing apparatus may also include a drive system that drives the test wheel and wheel frame. The tire testing apparatus may also include a drive system with a wheel frame drive means that drives the subframe against the road surface at a specified speed.In the aforementioned tire testing apparatus, the drive system may also include a test wheel drive mechanism that drives the test wheel. Alternatively, the test wheel drive mechanism may drive the test wheel at a rotational speed corresponding to a specified speed. The aforementioned tire testing apparatus may also include a first power generation mechanism that generates power for use on the drive subframe and the test wheel. The aforementioned tire testing apparatus may also include a power distribution mechanism that distributes the power generated by the first power generation mechanism to the wheel frame drive mechanism and the test wheel drive mechanism. The aforementioned tire testing apparatus may also include a first flexible belt drive mechanism that transmits the power generated by the first power generation mechanism. The aforementioned tire testing apparatus may also include a first flexible belt drive mechanism comprising: a drive pulley connected to the output shaft of a first power generating means; a driven pulley held on a wheel frame and connected to a test wheel; and a first flexible belt mediator mounted on the drive pulley and the driven pulley. The first flexible belt mediator has a first portion and a second portion that are stretched in the traveling direction of the wheel frame and driven in opposite directions. The first portion is connected to the driven pulley, and the second portion is fixed to the wheel frame. The aforementioned tire testing apparatus may also include a drive system comprising a secondary power transmission unit connected to the first flexible belt drive mechanism and transmitting at least a portion of the power transmitted by the first flexible belt drive mechanism to the drive unit. The aforementioned tire testing apparatus may also include a driven pulley connected to the input shaft of the secondary power transmission unit. In the aforementioned tire testing apparatus, the drive system may also include a pair of first power generating means, and the first flexible belt drive mechanism may include a pair of drive pulleys, which are respectively connected to the output shafts of the pair of first power generating means. The first flexible belt mediator forms a loop and is mounted on the pair of drive pulleys and driven pulleys. In the aforementioned tire testing apparatus, the first flexible belt mediator may also be a toothed belt with a steel wire core. In the aforementioned tire testing apparatus, the first flexible belt mediator may also be a toothed belt with a carbon wire core. In the aforementioned tire testing apparatus, it may also include a base on which rails are mounted. In the aforementioned tire testing apparatus, the test wheel drive means may also include a second power generating means, which generates power to rotate and drive the test wheel. In the aforementioned tire testing apparatus, the test wheel drive means may also include a power combining means, which combines the power generated by the first power generating means and the second power generating means. In the aforementioned tire testing apparatus, the first power generating means may include a first motor mounted on a base, and the second power generating means may include a second motor mounted on a wheel carrier. The aforementioned tire testing apparatus may also include a test wheel driving means comprising: a rotational motion supply means that supplies rotational motion corresponding to the speed of the wheel carrier; and a torque imparting means that changes the phase of the rotational motion supplied from the rotational motion supply means and imparts a specified torque to the test wheel.In the aforementioned tire testing apparatus, the rotational motion supply means may include a first motor mounted on a base, and the torque imparting means may include a second motor mounted on a wheel frame. The aforementioned tire testing apparatus may also include a power coupling means for the torque imparting means, which combines the power generated by the first motor and the power generated by the second motor. The aforementioned tire testing apparatus may also include a torque imparting means comprising: a rotating frame mounted on the second motor and driven to rotate by the power generated by the first motor; and a shaft driven by the second motor; with the shaft and rotating frame concentrically arranged. In the aforementioned tire testing apparatus, the torque-applying means may also include a pair of bearing portions that rotatably support a rotating frame. The rotating frame is cylindrical and includes: a motor housing portion that houses a second motor; and a pair of shaft portions that are positioned on both sides of the motor housing portion in the axial direction and are smaller in diameter than the motor housing portion. The shaft portions are rotatably supported by the pair of bearing portions. One side of the shaft portion is cylindrical, with a shaft rod passing through its hollow portion, and a bearing rotatably supporting the shaft rod is provided on the inner circumference of the shaft portion. The aforementioned tire testing apparatus may also include a secondary power transmission unit comprising: a second shaft rod driven by the torque-applying means; a bearing that rotatably supports the second shaft rod; and a sliding constant velocity joint that connects the second shaft rod to the main shaft. The aforementioned tire testing apparatus may also include a test wheel drive mechanism comprising: a primary power transmission unit that transmits power supplied from a rotary motion supply unit; and a secondary power transmission unit that is mounted on a wheel frame and connected to the primary power transmission unit, transmitting the power transmitted by the primary power transmission unit to the test wheel; the primary power transmission unit includes a first flexible belt drive mechanism, which includes: a pair of fixed pulleys that are mounted on the wheel frame to enclose a travelable area; a movable pulley that is held on the wheel frame; and a first flexible belt mediator that is mounted on the pair of fixed pulleys and the movable pulley; at least one of the fixed pulleys is a drive pulley connected to the output shaft of the rotary motion supply unit, and the movable pulley is a driven pulley connected to the input shaft of the secondary power transmission unit. In the aforementioned tire testing apparatus, the secondary power transmission unit may also include a second flexible belt drive mechanism. This second flexible belt drive mechanism comprises: a drive pulley, which is connected to the movable pulley of the first flexible belt drive mechanism; a driven pulley, which is connected to the rotating frame of the torque-applying means; and a second flexible belt medium joint, which is mounted on the drive pulley and the driven pulley of the second flexible belt drive mechanism. The aforementioned tire testing apparatus may also include a secondary power transmission unit with a rotatably supported main shaft. The main shaft has a force sensor, which is coaxially and detachably configured as a test wheel at its front end, and can detect the force applied to the test wheel. The aforementioned tire testing apparatus may also include a wheel frame comprising: a main frame; a rotating frame capable of rotating around a vertical line perpendicular to the road surface; and a sliding frame capable of sliding around the main frame in a vertical direction perpendicular to the road surface. The main shaft is supported by the main frame via the rotating frame and the sliding frame.The aforementioned tire testing apparatus may also include a wheel carrier equipped with: a curved guide way that guides the rotation of the rotating frame around a vertical line; and a straight guide way that guides the sliding frame to move vertically. The aforementioned tire testing apparatus may also include a sliding frame that rotatably supports the main shaft around a horizontal axis perpendicular to both the centerline and the vertical line of the main shaft. The aforementioned tire testing apparatus may also include a wheel carrier equipped with a load adjustment unit that adjusts the load applied to the test wheel by moving the sliding frame vertically. The aforementioned tire testing apparatus may also include a slip angle adjustment unit that adjusts the slip angle of the test wheel relative to the road surface by rotating the rotating frame around a vertical line. The aforementioned tire testing apparatus may also include a camber angle adjustment unit that adjusts the camber angle of the test wheel relative to the road surface by rotating the main shaft around a horizontal axis. The aforementioned tire testing apparatus may also include a load detection unit on the road surface that detects the load distribution borne by the tire tread of the test wheel. In the aforementioned tire testing apparatus, the load detection unit may be configured to have a plurality of load detection modules, which are arranged in a grid pattern in the driving direction of the wheel frame and the axial direction of the test wheel. The aforementioned tire testing apparatus may also be configured to have each load detection module equipped with a three-component force sensor. The aforementioned tire testing apparatus may also be configured to have a measuring means that measures the load distribution based on the detection results of the load detection unit, and the measuring means calculates the radial force, tangential force, and lateral force borne by the tire tread based on the detection results of the three-component force sensors. The aforementioned tire testing apparatus may also be configured to have a memory means that stores the detected load distribution. The aforementioned tire testing apparatus may also be configured to have a means for obtaining the driving position of the test wheel in the driving direction of the wheel frame, and the memory means stores the detected load distribution in correspondence with the driving position of the test wheel when the load distribution is detected. The aforementioned tire testing apparatus may also be configured to have a means for obtaining the rotational position of the test wheel, and the memory means stores the detected load distribution in correspondence with the rotational position of the test wheel when the load distribution is detected. In the aforementioned tire testing apparatus, a memory mechanism can be configured to remember the load distribution detected at the same time and the force applied to the test wheel. The aforementioned tire testing apparatus can also be configured to include a calculation mechanism that calculates the relative position of the load detection module, using the test wheel's travel position as a reference, and calculates the measured value of the load distribution with respect to the relative position. The aforementioned tire testing apparatus can also be configured to allow the wheel carrier to travel and perform load distribution detection multiple times, calculating the measured value of the load distribution by averaging the results of multiple load distribution detections at each relative position. The aforementioned tire testing apparatus can also be configured to calculate the measured value of the load distribution using regression analysis. The aforementioned tire testing apparatus can also be configured to allow the wheel carrier to travel in one direction, measure one set of loads using the load detection unit, and calculate the measured value of the load distribution based on the measurement results of multiple sets of loads measured by the load detection unit.The aforementioned tire testing apparatus may also be configured to include means for changing the position of the load detection unit to the axial direction of the test wheel. The aforementioned tire testing apparatus may also be configured to include means for changing the position of the load detection unit to the direction of travel. (Effects of the invention).

[0020] When one embodiment of the present invention is adopted, the road surface does not need to be moved during the test. By driving the test tire along the road surface, the tire can be tested on the bench under various road surface conditions.

Implementation Method

[0022] Hereinafter, one embodiment of the present invention will be described with reference to the drawings. Furthermore, in the following description, the same or corresponding symbols will be used to annotate the same or corresponding items, and repeated descriptions will be omitted. In addition, when multiple symbols are used to represent common items in the various figures, not all symbols used in these multiple representations will necessarily be used; instead, additional symbols may be appropriately omitted for a portion of these multiple representations. Furthermore, in each figure, for ease of explanation, some components may be omitted or shown in cross-section.

[0023] Figures 1 to 3 are, in sequence, a right side view, a top view, and a rear view of a tire testing device 1 according to an embodiment of the present invention. In addition, Figures 4 and 5 are, in sequence, enlarged right side views and top views of the main parts of the tire testing device 1.

[0024] In the top view (Figures 2 and 5), the direction from right to left is defined as the X-axis, the direction from top to bottom is defined as the Y-axis, and the direction perpendicular to the paper from the back to the surface is defined as the Z-axis. The X-axis and Y-axis are horizontal directions orthogonal to each other, and the Z-axis is a vertical direction. In addition, except in specific cases, the forward, backward, left, right, and up / down directions are defined as the directions when traveling towards the wheel frame 20 (positive X-axis direction). That is, the positive X-axis direction is called forward, the negative X-axis direction is called backward, the positive Y-axis direction is called left, the negative Y-axis direction is called right, the positive Z-axis direction is called up, and the negative Z-axis direction is called down. In addition, regarding the names of the figures, not limited to the above definitions, but following general practice, the side facing the right side (positive Y-axis direction) of the front is called the right side face, and the side facing the left side (negative Y-axis direction) is called the left side face.

[0025] The tire testing apparatus 1 includes: a track section 10 and a road surface 60 that are elongated in the X-axis direction; and a wheel frame 20 that can travel in the X-axis direction on the track section 10. As shown in FIG3, the road surface 60 is mounted on the left side of the base 11 (hereinafter referred to as "base 11") of the track section 10. A road surface 63a is provided on the road surface 60, which is in contact with the test tire T mounted on the wheel frame 20. In this embodiment, the road surface 60 is detachably mounted on the base 11 of the track section 10 so that the road surface 60 can be replaced according to the test conditions. In addition, the base 11 of the track section 10 and the frame 61 of the road surface 60 can also be integrated by means of welding, for example. Alternatively, the road surface 60 can be directly set on the base F (FIG. 3) and the road surface 60 can be completely separated from the track section 10.

[0026] As shown in FIG5, a pair of vehicle stops 13 are provided at the front end of the track section 10, adjacent to the drive sections 14LB and 14RB described later. The vehicle stops 13 are devices that collide with the wheel frame 20 when the wheel frame 20 is speeding, thereby forcibly stopping the wheel frame 20. Each vehicle stop 13 is equipped with a pair of hydraulic buffer devices to mitigate the impact generated when colliding with the wheel frame 20.

[0027] As shown in Figure 3, a test wheel W (that is, a rim Wr on which a test tire T is mounted) is installed on the wheel frame 20. During the test, the wheel frame 20 travels while the test wheel W is in contact with the road surface 63a, and the test wheel W rotates on the road surface 63a.

[0028] As shown in Figures 3 and 5, the track section 10 has a plurality of (three in the illustrated embodiment) guide mechanisms 12A, 12B and 12C that allow the guide wheel frame 20 to move in the X-axis direction. The guide mechanisms 12A, 12B and 12C are respectively located at the left end, the center of the width direction (i.e. the Y-axis direction) and the right end of the track section 10.

[0029] Figure 6 is a right side view of the guide mechanism 12A. Figures 7 and 8 are cross-sectional views of the guide mechanisms 12A and 12B, respectively. Since the guide mechanism 12C is symmetrical to the guide mechanism 12A, a detailed description of the guide mechanism 12C is omitted.

[0030] Each guide mechanism 12A, 12B, and 12C includes: a track 121 forming a track extending in the X-axis direction; and one or more (two in the illustrated embodiment) traveling parts 122A (Fig. 7), 122B (Fig. 8), or 122C (not shown. They are configured symmetrically with the traveling part 122A of the guide mechanism 12A.) As shown in Fig. 6, for the traveling parts 122A, 122B, and 122C, one of the two is mounted on the front end of the bottom surface of the wheel frame 20, and the other is mounted on the rear end.

[0031] As shown in Figures 7 and 8, the track 121 is laid on the base frame 11 of the track section 10. In addition, each of the traveling parts 122A, 122B and 122C is installed under the main frame 21 of the wheel frame 20.

[0032] Track 121 is a flat-bottomed track having a head 121h, a bottom 121f wider than the head 121h, and a belly 121w connecting the head 121h and the bottom 121f and having the narrowest width. Track 121 in this embodiment is, for example, a heat-treated track (e.g., heat-treated track 50N-HH340) according to Japanese Industrial Standard JIS E 1120:2007, on which additional processing is performed. A heat-treated track is a railway track whose wear resistance is improved by heat-treating the head.

[0033] As shown in FIG. 7, the traveling part 122A of the guiding mechanism 12A includes: a frame 123 extending in the X-axis direction and mounted below the main frame 21 of the wheel frame 20; and a plurality of roll units 128A mounted on the frame 123. Each roll unit 128A includes: three support rods 124a, 124b, and 124c mounted on the frame 123; and three roll assemblies 125a, 125b, and 125c respectively mounted on each of the support rods 124a, 124b, and 124c. The three roll assemblies 125a, 125b, and 125c of each roll unit 128A are arranged in the same position in the X-axis direction. Furthermore, as shown in FIG. 6, the plurality of roll units 128A are arranged at specified intervals in the X-axis direction.

[0034] Since roll assemblies 125b and 125c have the same structure as roll assembly 125a (however, roll assembly 125c is different in size from roll assembly 125a), only roll assembly 125a will be described to represent it, and repeated descriptions of roll assemblies 125b and 125c will be omitted.

[0035] As shown in FIG7, the roll assembly 125a includes: a roll 126a that rotates on a track 121; and a pair of bearings 127a that rotatably support the roll 126a. The bearings 127a are rolling bearings, and in the illustrated embodiment, ball bearings are used.

[0036] In this embodiment, the outer peripheral surface 126ap of the roll 126a is formed into a cylindrical surface, but it can also be a curved surface with curvature in the direction of the rotation axis (that is, in the longitudinal section containing the rotation axis shown in FIG7) (for example, a spherical surface with the center point 126ag of the roll 126a as the center).

[0037] The bearing 127a of the roll assembly 125a is, for example, a single-row radial bearing. The bearing 127a includes: an inner wheel 127a1 that engages with the rod 124a; an outer wheel 127a3 that engages with the inner circumferential surface of the roll 126a; and a plurality of balls 127a2 that are rotating bodies between the inner wheel 127a1 and the outer wheel 127a3. The balls 127a2 rotate on a circular track provided by a pair of annular grooves formed on the outer circumferential surface of the inner wheel 127a1 and the inner circumferential surface of the outer wheel 127a3.

[0038] The roll assembly 125a is configured such that its outer peripheral surface 126ap contacts the top surface (head surface) 121a of the track 121, and rotates on the top surface 121a as the wheel carrier 20 travels. The roll assembly 125b is configured such that its outer peripheral surface 126bp contacts one side of the bottom surface 121b of the track 121, and rotates on the bottom surface 121b. Furthermore, the roll assembly 125c is configured such that its outer peripheral surface 126cp contacts one side surface 121c of the track 121, and rotates on the side surface 121c.

[0039] The track 121, which contacts the head top 121a, head bottom 121b and head side 121c respectively with the roll assemblies 125a, 125b and 125c, changes its shape to a plane and performs additional processing (e.g., grinding and lapping) to improve the surface accuracy such as flatness and parallelism.

[0040] As described above, the guide mechanisms 12A and 12C, which are respectively installed at the left and right ends of the wheel frame 20, are configured symmetrically. That is, the guide mechanism 12C is configured in the opposite direction to the guide mechanism 12A (that is, rotated 180 degrees around the vertical axis).

[0041] As shown in FIG8, the traveling section 122B of the guide mechanism 12B includes: a frame 123 mounted below the main frame 21 of the wheel frame 20; and a plurality of roll units 128B mounted on the frame 123. Each roll unit 128B includes: two support rods 124a and 124b; and two roll assemblies 125a and 125b. Furthermore, the support rods 124b and roll assemblies 125b are positioned on the left side of the traveling section 122A of the guide mechanism 12A, while the traveling section 122B of the guide mechanism 12B is positioned on the right side of the track 121. That is, the traveling section 122B of the guide mechanism 12B is arranged in a reverse left-right configuration from the traveling section 122A of the guide mechanism 12A, omitting the roll assemblies 125c and the support rods 124c. Additionally, the traveling part 122B of the guiding mechanism 12B may include a roll assembly 125c and a rod 124c.

[0042] In this embodiment, the roller assemblies 125b and 125c of the guide mechanism 12A located on the left side of the track 121 prevent the wheel frame 20 from moving to the right (negative Y-axis direction) relative to the track 121. Furthermore, the roller assemblies 125b of the guide mechanism 12B and 125b and 125c of the guide mechanism 12C located on the right side of the track 121 prevent the wheel frame 20 from moving to the left (positive Y-axis direction) relative to the track 121. Therefore, the wheel frame 20 is prevented from moving relative to the track 121 in the Y-axis direction. Additionally, the roller assemblies 125b of the guide mechanisms 12A, 12B, and 12C prevent the wheel frame 20 from moving upwards (positive Z-axis direction) relative to the track 121. Thus, by preventing the wheel frame 20 from moving relative to the track 121 in both the Y-axis and positive Z-axis directions, the wheel frame 20 is prevented from derailing from the track 121.

[0043] In this embodiment, the traveling section 122B (Fig. 8) and the traveling section 122A (Fig. 7) are arranged in opposite left-right directions. However, the traveling section 122B and the traveling section 122A can also be arranged in the same left-right direction. Similarly, the traveling section 122C and the traveling section 122A can also be arranged in the same left-right direction. However, any two of the traveling sections 122A, 122B, and 122C are arranged in opposite left-right directions (that is, the roll assemblies 125b and 125c are arranged on opposite left-right sides of the track 121).

[0044] In order to prevent the wheel frame 20 from moving left and right (in the Y-axis direction), at least two traveling parts 122A, 122B or 122C arranged in opposite directions to each other may be equipped with a roll assembly 125c and a rod 124.

[0045] In order to prevent the wheel carrier 20 from moving upward (in the positive direction of the Z-axis), at least one traveling part 122A, 122B or 122C may be provided with a roll assembly 125b and a rod 124b.

[0046] When the angle at which the lower part 121b of the head of track 121 forms a horizontal plane is greater than a certain angle (e.g., 5°), roll assembly 125b can be used to replace roll assembly 125c.

[0047] The track 121 of the guide mechanism 12 may also be a connection of a plurality of short track components. In this case, as shown in FIG9, the joint 121j of the track 121 may not be perpendicular to the length direction (X-axis direction) of the track 121, but is formed at an angle when viewed from the plane (that is, the joint 121j is formed at an angle θ with respect to the ZX plane). By forming the joint 121j at an angle, even if the track 121 expands or contracts due to temperature changes, the strain of the track 121 is released by the sliding of each track component due to the joint 121j, thus preventing the track 121 from bending.

[0048] When forming the inclined joint 121j, roll assemblies 125b and 125c are arranged on the side of the track 121 that forms an obtuse angle with the joint 121j, in front of the joint 121j (that is, the left side in guide mechanism 12A, and the right side in guide mechanisms 12B and 12C) (Fig. 9). By arranging the roll assemblies 125b and 125c in this way, even if the joint 121j of the track 121 deviates, it can prevent the roll assemblies 125b and 125c from colliding with the acute angle end 121e of the joint 121j, thus preventing major impact or damage.

[0049] In addition, in the joint 121j, the end faces of the two connected track members can be in contact, or a specified gap can be provided between the end faces so that they are not in contact but tightly pressed together. Furthermore, in this embodiment, in the joint 121j of the track 121, the end faces of the two connected track members are only pressed together but not joined. However, the track members can also be joined in the joint 121j by welding or brazing.

[0050] Alternatively, a guide groove type circulating linear bearing (so-called linear guide) can be used to replace the guide mechanisms 12A, 12B, and 12C of this embodiment. The circulating linear bearing has an oblong track (i.e., the path for the rotation of the rotating body) connecting the adjacent ends of two parallel linear tracks with semi-circular tracks. When the linear bearing with this oblong track travels at high speed (e.g., speeds of 10 km / h or higher), when the rotating body moves from the linear track to the curved track, the rotating body rapidly generates centrifugal force (i.e., an impact load is applied to the rotating body and the rotating surface of the curved track), causing rapid wear or damage to the rotating body and the rotating surface. Therefore, when the wheel carrier 20 travels at high speed, there is a problem of shortened lifespan or damage to the linear bearing.

[0051] The bearings 127a-c used in the guide mechanisms 12A, 12B, and 12C of this embodiment do not experience sudden changes in centrifugal force (i.e., impact load) acting on the rotating body because the rotating body always travels on a circular track with a certain curvature. Therefore, even if the rolls 126a-c rotate at a high circumferential speed, for example, exceeding 60 km / h, the bearings 127a-c will not experience significant reduction in lifespan or breakage. Therefore, by using rolling bearings with a circular track having a certain curvature for the rotating body to construct the guide mechanisms 12A-C, the wheel frame 20 can travel at high speeds (e.g., speeds exceeding 10 km / h). The tire testing device 1 of this embodiment, by employing the above-described guide mechanisms 12A, 12B, and 12C, allows the wheel frame 20 to travel at speeds exceeding 85 km / h.

[0052] The tire testing apparatus 1 includes a drive subframe 20 and a drive system DS for the test wheel W. Figure 10 is a block diagram showing the general logical structure of the drive system DS. In addition, Figure 11 is a general mechanical structure diagram showing the main parts of the drive system DS. Furthermore, in Figure 10, the arrows indicate the transmission path of mechanical power (hereinafter referred to as "power").

[0053] As shown in Figure 10, the drive system DS includes: an engine AS that generates power; and a transmission TS that transmits the power generated by the engine AS to the wheel frame 20 and the test wheel W of the driven object. In addition, the drive system DS, together with the test wheel W and the road surface 60, constitutes a power circulation system.

[0054] The engine unit AS includes: two pairs of drive units 14 (first starting means) mounted on the left and right sides of the track unit 10; and a torque imparting device 30 (second starting means) mounted on the wheel frame 20. The drive units 14 are mainly used for controlling the travel speed of the wheel frame 20 and the rotation speed of the test wheel W, and the torque imparting device 30 is mainly used for controlling the torque imparted to the test wheel W.

[0055] The transmission unit TS includes: a first transmission unit TS1 that transmits the power generated by the drive unit 14 to the wheel frame 20; a second transmission unit TS2 that takes out a portion of the power transmitted by the first transmission unit TS1 and transmits it to the torque-applying device 30; and a third transmission unit TS3 that transmits the power output from the torque-applying device 30 to the test wheel W. In addition, the torque-applying device 30 also constitutes a part of the transmission unit TS.

[0056] As shown in Figures 4 and 5, two pairs of drive units 14 (one pair of drive units 14LA and 14LB on the left and one pair of drive units 14RA and 14RB on the right) are installed near the four corners of the base frame 11 of the track unit 10. Drive units 14LA and 14RA are located at the rear end of the track unit 10, and drive units 14LB and 14RB are located at the front end of the track unit 10.

[0057] As described later, the drive units 14RA and 14RB on the right side also function as a wheel frame drive means to drive the wheel frame 20 to travel; and as a test wheel drive means (rotation input means) to drive the test wheel W to rotate at a number of revolutions corresponding to the travel speed of the wheel frame 20. The drive units 14LA and 14LB on the left side function as wheel frame drive means.

[0058] The first transmission unit TS1 includes one pair each of belt mechanisms 15 (15L, 15R) and driven parts (first driven part 22 and second driven part 23). The left belt mechanism 15L is driven by a pair of drive parts 14LA and 14LB on the left side, and the right belt mechanism 15R is driven by a pair of drive parts 14RA and 14RB on the right side. The first driven part 22 and the second driven part 23 are mounted on the main frame 21 of the wheel frame 20. The first driven part 22 is connected to the right belt mechanism 15R, and the second driven part 23 is connected to the left belt mechanism 15L.

[0059] Figure 12 is a schematic structural diagram showing the drive pulley section 150 of the drive unit 14 and the belt mechanism 15. Figure 13 is a top view of the first driven unit 22. Figures 14, 15 and 16 are, in sequence, cross-sectional views A-A, B-B and C-C of Figure 13. In addition, Figure 17 is a cross-sectional view showing the schematic structure of the second driven unit 23.

[0060] Each belt mechanism 15 (15L, 15R) includes: a pair of drive pulley sections 150; belts 151 (151L, 151R); three driven pulleys 155A, 155C, and 156 (Fig. 14) held in the first driven section 22 or three driven pulleys 155A, 155B, and 155C (Fig. 17) held in the second driven section 23; and a pair of belt clamps 157 (Figs. 3, 5) that are respectively fixed to both ends of the belt 151 on the main frame 21 of the wheel frame 20. The drive pulley section 150 is mounted on the base frame 11 of the track section 10 and connected to the corresponding drive section 14.

[0061] Belt 151R is wound around a pair of drive pulleys (152A, 152B) of drive pulley section 150 and three driven pulleys 155A, 155C and 156. Belt 151L is wound around a pair of drive pulleys (152A, 152B) of drive pulley section 150 and three driven pulleys 155A, 155B and 155C.

[0062] The drive unit 14 includes a motor 141 (first motor) and a belt mechanism 142. The motor 141 is, for example, an ultra-low inertia, high-output AC servo motor with a rotational torque of 0.01 kg·m2 or less (more preferably 0.008 kg·m2 or less) and a rated output of 3 kW to 60 kW (more practically 7 kW to 37 kW). By using this ultra-low inertia and high-output motor 141, the wheel frame 20 can be accelerated to the maximum speed of the test tire T (e.g., 240 km / h) over a short travel distance (e.g., 20 to 50 m).

[0063] Alternatively, motor 141 may be a motor whose rotating part has a standard torque of inertia. In addition, motor 141 may also be another type of electric motor whose speed can be controlled, such as a so-called converter motor that uses a converter for drive control.

[0064] The belt mechanism 142 includes: a drive pulley 142a mounted on the shaft 141b of the motor 141; a driven pulley 142c; and a belt 142b wound around the drive pulley 142a and the driven pulley 142c. The belt 142b is, for example, a toothed belt with the same configuration as the belt 151 described later. The type of belt 142b may also be different from that of belt 151.

[0065] Because the pitch circle diameter of the driven pulley 142c is larger than that of the driving pulley 142a (i.e., more teeth), the belt mechanism 142 has a reduction ratio greater than 1. Therefore, the rotation output from the motor 141 is reduced in speed by the belt mechanism 142. In addition, the reduction ratio of the belt mechanism 142 can also be less than 1. Alternatively, a speed reducer can be installed in the drive unit 14 to replace the belt mechanism 142 (or added to it). Alternatively, the belt mechanism 142 and the speed reducer can be omitted, and the shaft 141b of the motor 141 can be directly connected to the shaft 153 of the belt mechanism 15 (described later).

[0066] A drive pulley section 150 is disposed adjacent to the drive unit 14, comprising a belt mechanism 15. The drive pulley section 150 includes: a pair of bearing sections 154; a shaft 153 rotatably supported by the pair of bearing sections 154; and a drive pulley 152 mounted on the shaft 153. The driven pulley 142c of the belt mechanism 142 is also mounted on the shaft 153, and the output of the drive unit 14 is transmitted to the belt 151 wound around the drive pulley 152 via the shaft 153 and the drive pulley 152.

[0067] The belt 151 is a toothed belt with a steel wire core. Alternatively, the belt 151 can also use a core made of, for example, so-called microfibers such as carbon fiber, aromatic polyamide fiber, or ultra-high molecular weight polyethylene fiber. By using a lightweight and high-strength core such as carbon fiber, a motor with relatively low output can be used to drive the subframe 20 with high acceleration (or to impart high driving / braking force to the test wheel W), thus miniaturizing the tire testing device 1. Furthermore, when using a motor with the same output, by using a lightweight belt 151 with a core made of so-called microfibers, the tire testing device 1 can achieve higher performance (specifically, improved acceleration performance).

[0068] As shown in Figures 3 to 5, both ends of each belt 151 are fixed to the main frame 21 of the wheel frame 20. Thus, each belt 151 forms a loop via the wheel frame 20. When each belt mechanism 15 is in operation, the wheel frame 20 travels in the X-axis direction by being stretched by each belt 151.

[0069] In this embodiment, the belt 151 is fixed to the wheel frame 20 via a belt clamp 157 on the lower side of the ring, and the belt mechanism 15 is connected to the first driven part 22 or the second driven part 23 on the upper side of the ring. By positioning the belt clamp 157, which has a lower height, below the first driven part 22 or the second driven part 23, the height of the belt mechanism 15 can be reduced. Alternatively, the belt 151 can be fixed to the wheel frame 20 on the upper side of the ring.

[0070] As shown in Figure 4, one pair of drive pulleys 152 (152A, 152B) of the belt mechanism 15 are fixed pulleys that clamp the travelable area in the middle and are mounted on the base frame 11 (that is, the center of gravity is fixed to the base frame 11). In addition, the driven pulleys 155 (155A, 155B, 155C) and 156 held in the first driven part 22 or the second driven part 23 are movable pulleys that can move in the X-axis direction together with the wheel frame 20.

[0071] In the following description, the configuration of a pair of left and right sides will be described in principle only for the left side. The configuration of the right side will be described together with the square brackets, and repeated descriptions will be omitted.

[0072] In this embodiment, the pair of drive units 14LA and 14LB (14RA and 14RB) are driven in the same phase. In addition, the drive units 14LA and 14LB on the left and the drive units 14RA and 14RB on the right are arranged in opposite directions and are driven in opposite phases.

[0073] The effective diameter (i.e., pitch circle diameter) or number of teeth of the drive pulley 152 (FIG. 12) and the driven pulley 155 (FIG. 14, FIG. 17) are the same. The pitch circle diameter or number of teeth of the driven pulley 156 (FIG. 14) held in the first driven part 22 is larger (e.g., twice) than that of the drive pulley 152 and the driven pulley 155.

[0074] As shown in FIG. 5, the wheel frame 20 includes: a main frame 21, a first driven part 22, a second driven part 23, a belt mechanism 24, a belt mechanism 25, a drive shaft part 26, a brake device 27, a brake device 28, a torque imparting device 30, an alignment part 40, and a main shaft part 50 (axle part). Furthermore, as shown in FIG. 10, the first driven part 22 and the belt mechanism 24 constitute a second transmission part TS2. In addition, the belt mechanism 25, the drive shaft part 26, and the main shaft part 50 constitute a third transmission part TS3.

[0075] As shown in Figure 11, the main shaft section 50 has a main shaft 52 that is rotatably supported. The main shaft 52 is an axle (i.e., axle) coaxially (i.e., sharing the centerline) with the test wheel W, and drives the test wheel W to rotate together with the main shaft 52 by the power output from the torque imparting device 30. The alignment section 40 is a mechanism that can adjust the wheel alignment (alignment adjustment) of the test wheel W by changing the direction of the main shaft section 50.

[0076] As shown in Figures 13 to 16, the first driven part 22 includes: a body part 221, a bearing part 222, a bearing part 223, a shaft 224, a drive gear 225, a shaft 226, and a driven gear 227.

[0077] As shown in FIG. 14, the main body 221 includes: two support rods 221b extending in the Y-axis direction; and a pair of bearings 221c whose inner wheels engage with each rod 221b. The driven pulleys 155A and 155C of the belt mechanism 15R are respectively engaged with the outer wheels of each bearing 221c. With this configuration, the driven pulleys 155A and 155C of the belt mechanism 15R are rotatably supported by the main body 221.

[0078] As shown in FIG16, the main body 221 includes a bearing 221a. The bearing part 222 includes a pair of bearings 222a and 222b arranged vertically side by side. In addition, the bearing part 223 includes a pair of bearings 223a and 223b arranged vertically side by side.

[0079] The shaft 224 is rotatably supported at one end along its length by a bearing 221a, at the other end by a bearing 223a, and in the middle by a bearing 222a. A driven pulley 156 and a drive gear 225 of a belt mechanism 15R are mounted in the shaft 224.

[0080] Shaft 226 is shorter than shaft 224, and is rotatably supported at one end of its length by bearing 222b and at the other end by bearing 223b. A driven gear 227 that meshes with drive gear 225 and a drive pulley 241 of belt mechanism 24 are mounted on shaft 226.

[0081] That is, the driven pulley 156 (belt mechanism 15R) and the drive pulley 241 (belt mechanism 24) are connected via the first driven part 22. A portion of the power transmitted by the belt mechanism 15R is transmitted to the shaft 224 via the driven pulley 156, then to the shaft 226 via the drive gear 225 and the driven gear 227, and further to the belt mechanism 24 via the drive pulley 241. The power transmitted to the belt mechanism 24 is used to drive the test wheel W.

[0082] That is, the first driven part 22 on the right side and the driven pulley 156 (and driven pulleys 155A and 155C) that are rotatably supported by the first driven part 22 have the function of taking a portion of the power from the belt mechanism 15R and supplying it to the belt mechanism 24.

[0083] The remaining portion of the power transmitted by the belt mechanism 15R is transmitted to the main frame 21 of the wheel frame 20, which is fixed with the belt 151, via the belt clamp 157, and is used to drive the sub-frame 20.

[0084] That is, the belt mechanism 15R on the right side constitutes part of the means of driving the wheel frame 20 (wheel frame drive means), and also constitutes part of the means of driving the test wheel W (test wheel drive means). In addition, the belt mechanism 15R on the right side, together with the first driven part 22 on the right side, functions as a means of distributing the power generated by the drive parts 14RA and 14RB into power used for driving the wheel frame 20 and power used for driving the test wheel W (power distribution means).

[0085] In this embodiment, the belt mechanism 15R has a reduction ratio greater than 1 because the pitch circle diameter of the driven pulley 156 on the output side is larger than that of the driving pulley 152 on the input side. However, the present invention is not limited to this configuration; the pitch circle diameter of the driven pulley 156 can also be made larger than that of the driving pulley 152, resulting in a reduction ratio of less than 1 for the belt mechanism 15R.

[0086] Furthermore, the first driven part reverses the rotation direction of the power by including the drive gear 225 and the driven gear 227.

[0087] As shown in FIG17, the second driven part 23 (body part 231) includes: three support rods 231b extending in the Y-axis direction; and three bearings 231c that engage with each rod 231b via an inner wheel. The three support rods 231b are arranged at equal intervals in the X-axis direction. In this embodiment, the central rod 231b is positioned higher than the remaining two support rods 231b; however, all rods 231b may also be positioned at the same height.

[0088] Each bearing 231c has three driven pulleys 155 of the belt mechanism 15L (from front to back, they are driven pulleys 155A, 155B and 155C) fitted onto its outer wheel. With this configuration, the driven pulleys 155A, 155B and 155C of the belt mechanism 15L are rotatably supported by the second driven part 23.

[0089] As shown in Figure 4, the belt 151 of the belt mechanism 15 is divided into an upper portion 151a and a lower portion 151b by the drive pulleys 152A and 152B folding back. The upper portion 151a and the lower portion 151b extend in the traveling direction of the wheel frame 20 and drive each other in opposite directions. Specifically, the lower portion 151b of the belt 151 fixed to the wheel frame 20 is driven together with the wheel frame 20 in the traveling direction of the wheel frame, while the upper portion 151a drives in the opposite direction to both the wheel frame 20 and the lower portion 151b. In addition, the driven pulleys 155 and 156 mounted on the wheel frame 20 are wound around the upper portion 151a of the belt 151, which travels in the opposite direction to the wheel frame 20, and are driven by the upper portion 151a.

[0090] As shown in Figures 10 and 11, a portion of the power transmitted by the belt mechanism 15R on the right side is transmitted to the torque-applying device 30 via the second transmission unit TS2, and further transmitted to the test wheel W via the third transmission unit TS3, thereby driving the test wheel W. The second transmission unit TS2 includes a first driven part 22 and a belt mechanism 24, while the third transmission unit TS3 includes a belt mechanism 25, a drive shaft part 26, and a main shaft part 50. As described above, the remaining portion of the power transmitted by the belt mechanism 15R on the right side is transmitted to the main frame 21 of the wheel frame 20, which is fixed at the front end of the belt 151, via the belt clamp 157, thereby driving the wheel frame 20. With the belt mechanism 15R and the first driven part 22 configured as described above, both the wheel frame 20 and the test wheel W can be driven by the belt 151.

[0091] Furthermore, the difference between the second driven part 23 on the left and the first driven part 22 on the right is that it does not have a structure for extracting a portion of the power transmitted via the belt mechanism 15L and transmitting it to the second transmission part TS2 provided on the wheel frame 20 (specifically, bearings 222, 223, shafts 224, 226, drive gear 225, and driven gear 227). In addition, the second driven part 23 on the left is not a necessary component; however, by providing the second driven part 23 on the left, the force received by the wheel frame 20 from the left and right belt mechanisms 15L and 15R is balanced, and the driving stability of the wheel frame 20 is improved.

[0092] As described above, this embodiment uses power transmitted by a common power transmission device (i.e., belt mechanism 15R) to drive the wheel frame 20 and the test wheel W. With this configuration, regardless of the travel speed of the wheel frame 20, the test wheel W can always be driven to rotate at a circumferential speed (number of revolutions) corresponding to the travel speed of the wheel frame 20. Furthermore, in order to reduce the workload (in other words, power consumption) of the torque-applying device 30, this embodiment drives the test wheel W to rotate at a circumferential speed approximately equal to the travel speed of the wheel frame 20 when the torque-applying device 30 is not operating.

[0093] The belt mechanism 24 includes: a drive pulley 241 mounted on the shaft 226 (Fig. 16) of the first driven part 22 described above; a driven pulley 242 mounted on the shaft 314 (Fig. 18) of the torque applying device 30 described later; and a belt 243 wound around the drive pulley 241 and the driven pulley 242. The belt 243 is, for example, a toothed belt with the same configuration as the belt 151 described above. The type of belt 243 may also be different from that of belt 151.

[0094] Figure 18 is a structural diagram showing the torque applying device 30. The torque applying device 30 generates a torque that is applied to the test wheel W and outputs the torque by applying it to the rotational motion transmitted by the belt mechanism 24. In other words, the torque applying device 30 can apply torque to the test wheel W (that is, apply driving or braking force between the road surface 63a and the test wheel W) by changing the phase of the rotational motion transmitted by the belt mechanism 24.

[0095] The torque imparting device 30 functions as a second starting means to generate power to drive the test wheel W, and also functions as a power combining means to combine the power generated by the motor 141 (first motor) of the drive unit 14 (first starting means) with the power generated by the motor 32 (second motor) of the torque imparting device 30 described later.

[0096] By inserting the torque-applying device 30 into the drive system DS, the power source (drive units 14RA, 14RB) for controlling the rotation speed of the test wheel W and the power source for controlling the torque (motor 32 described later) can share the same role. This allows for the use of a smaller capacity power source and enables more precise control of the rotation speed and torque applied to the test wheel W. Furthermore, by inserting the torque-applying device 30 into the wheel frame 20, the load applied to the belt mechanism 15R is reduced, thus enabling miniaturization of the belt mechanism 15R (e.g., reducing the number of toothed belts used) and the use of components with lower load-bearing capacity.

[0097] The torque imparting device 30 includes: a rotating frame 31; a motor 32 (second motor) installed in the rotating frame 31; a reducer 33 and a shaft 34; three bearings 351, 352 and 353 that rotatably support the rotating frame 31; a sliding ring 37; and a rotary encoder 38 for detecting the rotation of the rotating frame 31.

[0098] In this embodiment, the motor 32 uses an ultra-low inertia high-output AC servo motor with a rotating part inertial torque of 0.01 kg‧m2 or less (more preferably 0.008 kg‧m2 or less) and a rated output of 3 kW to 60 kW (more practically 7 kW to 37 kW).

[0099] The rotating frame 31 includes: a first cylindrical portion 311 (motor housing) with a large diameter, roughly cylindrical in shape; a second cylindrical portion 312 (connecting cylinder) and a third cylindrical portion 313; and shaft portions 314 and 315 with diameters smaller than the first cylindrical portion 311. One end of the first cylindrical portion 311 (the right end in FIG. 18) is coaxially connected to the shaft portion 314 via the second cylindrical portion 312 and the third cylindrical portion 313. Furthermore, the other end of the first cylindrical portion 311 (the left end in FIG. 18) is coaxially connected to the shaft portion 315. The shaft portion 314 is rotatably supported by bearing portions 351 and 353, and the shaft portion 315 is rotatably supported by bearing portion 352.

[0100] A motor 32 is housed in the hollow portion of the first cylindrical section 311. The motor 32 and the rotating frame 31 are coaxially mounted on a shaft 321, and the motor housing 320 (i.e., the stator) is fixed to the first cylindrical section 311 by a plurality of double-headed bolts 323.

[0101] A speed reducer 33 is disposed in the hollow portion of the second cylindrical section 312 and the third cylindrical section 313. The input shaft 332 of the speed reducer 33 is connected to the shaft 321 of the motor 32, and the output shaft 333 is connected to the shaft 34.

[0102] A flange 312a protruding outward is formed at one end of the second cylindrical portion 312 (the right end in FIG18). A flange 312b protruding outward and an inner flange 312c protruding inward are formed at the other end of the second cylindrical portion 312 (the left end in FIG18).

[0103] The flange 320a of the motor 32 is fixed to the inner flange 312c of the second cylindrical portion 312. The gearbox 331 of the reducer 33 is fixed to one end of the second cylindrical portion 312 (i.e., the root of the flange 312a). That is, the motor housing 320 of the motor 32 and the gearbox 331 of the reducer 33 are connected with high rigidity via the second cylindrical portion 312 of a single short cylindrical member. In this way, almost no bending moment is applied to the shaft 321 of the motor 32 and the input shaft 332 of the reducer 33, which ensures smooth (i.e., low-friction) rotation of the shaft 321 and the input shaft 332, and improves the control accuracy of the torque of the test wheel W.

[0104] A flange 315a of the same diameter as the first cylindrical portion 311 is formed at the root of the shaft portion 315, and one end of the first cylindrical portion 311 is fixed to the outer periphery of the flange 315a. Furthermore, the flange 320b of the motor 32 is fixed to the flange 315a of the first cylindrical portion 311. Because the motor 32 is supported with high rigidity at both ends and the center of the motor housing 320 along its length direction, the rotating frame 31 is fixed to it.

[0105] A flange 314a of the same diameter as the third cylindrical portion 313 is formed at the root of the shaft portion 314. One end of the third cylindrical portion 313 is fixed to the outer periphery of the flange 314a. In addition, the other end of the third cylindrical portion 313 is fixed to the outer periphery of the flange 312a of the second cylindrical portion 312.

[0106] The shaft portion 314 is rotatably supported near the flange 314a on the base side by bearing portion 351, and the front end portion is rotatably supported by bearing portion 353. A driven pulley 242 of the belt mechanism 24 is disposed between bearing portion 351 and bearing portion 353 and is coaxially mounted on the outer periphery of the shaft portion 314. The rotation of the torque-generating device 30 is driven by the power transmitted by the belt mechanism 24. That is, the shaft portion 314 (rotating frame 31) becomes the input shaft of the torque-generating device 30.

[0107] A pair of bearings 314b are provided on the inner circumference of both ends of the shaft portion 314 (i.e., the portions supported by bearing portions 351 or 353). The shaft 34 is rotatably supported by the pair of bearings 314b through the hollow portion of the shaft portion 314. The front end of the shaft 34 protrudes outward from the front end of the shaft portion 314. A drive pulley 251 of the belt mechanism 25 is coaxially mounted on the front end of the shaft 34 protruding from the shaft portion 314, and the belt mechanism 25 is driven by the power output from the shaft 34. That is, the shaft 34 becomes the output shaft of the torque imparting device 30.

[0108] The torque output from the motor 32 is amplified by the reducer 33 and transmitted to the shaft 34. The rotation output from the shaft 34 to the belt mechanism 25 becomes a torque superimposed on the rotation of the rotating frame 31 driven by the belt mechanism 24 by the torque generated by the motor 32 and the reducer 33. The torque imparting device 30 adds the torque generated by the torque imparting device 30 to the rotational motion of the shaft portion 315 of the rotating frame 31 transmitted to the input shaft, and outputs it from the shaft 34 of the output shaft.

[0109] The sliding ring portion 37 includes: a plurality of sliding rings 371 and brushes 372, a support tube 373, a bearing portion 374, a support column 375, and a support arm 376. The support tube 373 is coaxially connected to the shaft portion 315 of the rotating frame 31. The front end of the support tube 373 is rotatably supported by the bearing portion 374. The support arm 376 is arranged parallel to the support tube 373, with one end fixed to the support column 375 arranged on the side of the rotating frame 31, and the other end fixed to the frame of the bearing portion 374.

[0110] A plurality of sliding rings 371 are arranged at certain intervals in the axial direction and are mounted on the outer periphery of the support tube 373. A plurality of brushes 372 are arranged to contact the outer peripheral surfaces of their respective corresponding sliding rings 371 and are mounted on the support arm 376.

[0111] Each sliding ring 371 is connected to a wire (not shown). The wire is pulled out through the hollow part of the support tube 373 to the hollow part of the shaft 315 of the rotating frame 31. The cable 325 of the motor 32 passes through the hollow part of the shaft 315, and the plurality of steel wires contained in the cable 325 are connected to the wires of the corresponding sliding rings 371. In addition, the brush 372 is connected to the drive wheel 32a (Fig. 38). That is, the motor 32 and the drive wheel 32a are connected via the sliding ring 37.

[0112] The rotary encoder 38 is mounted on the bearing portion 374 of the sliding ring portion 37. In addition, a support tube 373 that rotates integrally with the rotating frame 31 is connected to the input shaft of the rotary encoder 38.

[0113] As shown in Figure 11, the belt mechanism 25 includes: a drive pulley 251 mounted on the output shaft (shaft 34) of the torque-applying device 30; a driven pulley 252 mounted on the input shaft (drive shaft 261) of the drive shaft section 26; and a belt 253 wound around the drive pulley 251 and the driven pulley 252; and transmits the power output from the torque-applying device 30 to the drive shaft section 26. The belt 253 is, for example, a toothed belt with the same configuration as the belt 151 described above. The type of belt 253 may also be different from that of the belt 151.

[0114] The drive shaft section 26 includes: a drive shaft 261, a pair of bearing sections 262 that rotatably support the drive shaft 261, a disc brake 263, a sliding constant velocity joint 265, a drive shaft 266, and a bearing 267 that rotatably supports the drive shaft 266. The disc brake 263 includes: a disc rotor 263a mounted on the drive shaft 261; and a clip 263b that applies friction to the disc rotor 263a for braking.

[0115] One end of the drive shaft 261 is fitted with the driven pulley 252 of the belt mechanism 25, and the other end is connected to one end of the sliding constant velocity joint 265 via a disc rotor 263a. The other end of the sliding constant velocity joint 265 is connected to the main shaft 52 via the drive shaft 266. The sliding constant velocity joint 265 is configured to smoothly transmit rotation without changing the rotation angle (i.e., the angle formed by the input shaft and the output shaft) regardless of the working angle. Furthermore, the length (transmission distance) of the sliding constant velocity joint 265 in the axial direction is also variable.

[0116] The main shaft 52, on which the test wheel W is mounted, is variably supported in terms of angle and position by the alignment part 40. The drive shaft 261 and the main shaft 52 are connected via a sliding constant velocity joint 265, which adapts to changes in the angle and position of the main shaft 52. Therefore, power can be smoothly transmitted without applying large strain to the main shaft 52 and the drive shaft 261.

[0117] Figure 19 is a schematic structural diagram showing the alignment part 40. In addition, Figures 20, 21, 22 and 23 are, in order, views in the direction of arrow A-A, arrow B-B, arrow C-C and arrow D-D of Figure 19.

[0118] The alignment part 40 includes: a load adjustment part 42, an outward tilt adjustment part 44 and a slip angle adjustment part 46.

[0119] The load adjustment unit 42 adjusts the load (vertical load borne from the road surface 63a) applied to the test wheel W by changing the height of the main shaft 52 and the test wheel W mounted on the main shaft 52 (more specifically, the distance from the road surface 63a to the center C of the test wheel W). The load adjustment unit 42 includes: a lifting frame 421 (first movable frame) that can move up and down (in the Z-axis direction) to the base frame 11; a plurality of linear guide rails 422 (two pairs in the illustrated embodiment) that guide the lifting frame 421 to move up and down; and one or more Z-axis drive units 43 (one pair in the illustrated embodiment) that drive the lifting frame 421 up and down.

[0120] A small house-shaped (or pavilion-shaped) alignment mechanism support 214 for housing the alignment part 40 is provided on the left side of the main frame 21 of the wheel frame 20. The lifting frame 421 is housed within the alignment mechanism support 214. The linear guide rail 422 includes: a vertically extending track 422a; and one or more (two in the illustrated embodiment) traveling parts 422b that can travel on the track 422a. One of the track 422a and the traveling part 422b of each linear guide rail 422 is mounted on the alignment mechanism support 214, and the other is mounted on the lifting frame 421.

[0121] The Z-axis drive unit 43 (first drive unit) includes: a motor 431; and a ball screw 432 (motion converter) that converts the rotational motion of the motor 431 into linear motion in the Z-axis direction. The ball screw 432 includes: a helical shaft 432a connected to the shaft of the motor 431; a nut 432b engaging with the helical shaft 432a; and bearings 432c and 432d that rotatably support the helical shaft 432a. The motor 431 and the two bearings 432c and 432d are mounted on the alignment mechanism support 214, and the nut 432b is mounted on the lifting frame 421.

[0122] When the ball screw 432 is driven by the motor 431, the lifting frame 421 and the nut 432b move up and down together. Subsequently, the test wheel W is raised and lowered via the outward tilt adjustment part 44, the slip angle adjustment part 46 and the main shaft part 50 supported on the lifting frame 421, and a load is applied to the test wheel W according to the driving amount of the ball screw 432 (that is, the height of the test wheel W).

[0123] In this embodiment, the motor 431 is directly connected to the screw shaft 432a. However, it can also be configured to connect the motor 431 and the screw shaft 432a via a reducer or a gear device that reduces the rotation of a worm gear.

[0124] In this embodiment, a feed screw mechanism is used as a motion converter. However, other types of motion converters that can convert rotary motion into linear motion can be used.

[0125] The motor 431 in this embodiment is a servo motor. However, other types of motors with controllable workload can also be used as motor 431.

[0126] The camber adjustment unit 44 is a mechanism that adjusts the camber angle of the test wheel W relative to the road surface by rotating the main shaft 52 around the Eφ axis (an axis extending forward and backward through the center C of the test wheel W). The camber adjustment unit 44 includes: a ϕ rotating frame 441 (second movable frame) that can rotate around the Eφ axis; a pair of bearings 442 that rotatably support the ϕ rotating frame 441; a pair of curved guide rails 443 that guide the rotation of the ϕ rotating frame 441; and a pair of ϕ drive units 45 (second drive units) that drive the ϕ rotating frame 441 to rotate left and right.

[0127] As shown in Figure 19, the ϕ-rotating frame 441 and the lifting frame 421 of this embodiment have a gate-shaped (∩-shaped) shape when viewed in the Y-axis direction. The ϕ-rotating frame 441 is housed in the hollow portion of the ∩-shaped lifting frame 421. Cylindrical pivots 441a are provided on the front and back of the ϕ-rotating frame 441, respectively protruding outwards (i.e., from the direction away from the test wheel W) coaxially with the Eφ axis. Each pivot 441a is rotatably supported by a pair of bearings 442 mounted on the lifting frame 421. The ϕ-rotating frame 441 is rotatably supported around the Eφ axis, using the pivots 441a as support shafts. Alternatively, the bearings 442 can be mounted on the ϕ-rotating frame 441, and the pivots 441a can be mounted on the lifting frame 421. Furthermore, the shapes of the rotating frame 441 and the lifting frame 421 are not limited to the shape of this embodiment, as long as they have a hollow portion that can accommodate the main shaft portion 50, etc.

[0128] The curved guide rail 443 includes: an arc-shaped curved track 443a arranged concentrically with the Eφ axis; and one or more (two in the illustrated embodiment) traveling parts 443b that can travel on the curved track 443a. One of the curved track 443a and the traveling parts 443b is mounted on the lifting frame 421, and the other is mounted on the ϕ rotating frame 441.

[0129] The ϕ drive unit 45 includes: a pair of spur gears 453 respectively mounted on the front and back of the ϕ rotating frame 441; a pair of pinions 452 respectively meshing with each spur gear 453; and a pair of motors 451 driving each pinion 452. Alternatively, the spur gears 453 can be mounted on the lifting frame 421, and the motors 451 can be mounted on the ϕ rotating frame 441. The spur gears 453 are sector gears formed in an arc shape with the Eφ axis as the center (i.e., coaxial with the Eφ axis). In the illustrated embodiment, the spur gears 453 are internal gears, but they can also be external gears.

[0130] The motor 451 is mounted on the lifting frame 421, and the pinion 452 is engaged with the shaft 451s of the motor 451. In addition, the motor 451 in this embodiment is a servo motor, but other types of motors that can control the workload can also be used as motor 451.

[0131] When the motor 451 drives the pinion 452 to rotate, the spur gear 453 meshing with the pinion 452 together causes the ϕ rotating frame 441 to rotate around the lifting frame 421 around the Eφ axis. Subsequently, the test wheel W supported by the ϕ rotating frame 441 rotates around the Eφ axis via the slip angle adjustment part 46 and the main shaft part 50, and the outward tilt angle changes.

[0132] The slip angle adjustment unit 46 is a mechanism that adjusts the slip angle of the test wheel W (more specifically, the wheel center plane perpendicular to the axle) relative to the travel direction (X-axis direction) of the wheel carrier 20 by changing the direction around the Eθ axis of the main shaft 52 (an axis extending vertically through the center C of the test wheel W). As shown in FIG19, the slip angle adjustment unit 46 includes: an θ rotating frame 461 (third movable frame) that can rotate with the Eθ axis as the center; a bearing 462 that rotatably supports the θ rotating frame 461; and an θ drive unit 47 that drives the θ rotating frame 461 to rotate.

[0133] The θ-rotating frame 461 is housed in a hollow portion of the ϕ-rotating frame 441, which forms a gate-shaped (∩-shaped) configuration when viewed in the Y-axis direction. A pivot 461a protrudes coaxially from the Eθ-axis on the top of the θ-rotating frame 461. The pivot 461a is rotatably supported by a bearing 462 mounted on the top plate of the ϕ-rotating frame 441. The θ-rotating frame 461 is rotatably supported about the Eθ-axis, with the pivot 461a serving as a support shaft.

[0134] The θ drive unit 47 includes: a spur gear 473 mounted on the θ rotating frame 461; one or more pinions 452 (a pair in the illustrated embodiment) meshing with the spur gear 473; and one or more motors 471 (a pair in the illustrated embodiment) that drive each pinion 452 to rotate. The spur gear 473 is coaxially coupled to the pivot 461a. The motor 471 is mounted on the θ rotating frame 441, and the pinions 452 are mounted on the shaft of the motor 471.

[0135] Figure 24 is a schematic structural diagram showing the main shaft portion 50 (wheel support portion). The main shaft portion 50 is mounted on the lower end of the θ rotating frame 461. The main shaft portion 50 includes: a frame 51 fixed to the θ rotating frame 461; a plurality of bearings 53 (a pair in the illustrated embodiment) mounted on the frame 51; a main shaft 52 rotatably supported on the bearings 53; a six-component force sensor 54 for detecting the force applied to the test wheel W; and a wheel hub 55 coaxially mounted to the front end of the main shaft 52 via the six-component force sensor 54. The six-component force sensor 54 includes a plurality of piezoelectric elements (not shown). The rim Wr of the test wheel W is mounted in the wheel hub 55 (Figure 1).

[0136] A drive shaft 266 is connected to the end of the main shaft 52 via a drive shaft section 26. The drive shaft 266 is rotatably supported by a bearing 267 mounted on the frame 51 of the main shaft section 50.

[0137] The alignment part 40 is configured such that even if the outward tilt angle (ϕ angle) and the slip angle (θ angle) are changed, the position of the test wheel W does not move, and the three axes of Eθ axis, Eϕ axis and Eλ axis intersect at a point C at the center of the test wheel W.

[0138] Figure 25 is a cross-sectional view of the pavement surface 60. The pavement surface 60 includes: a frame 61; and a body portion 60a supported on the frame 61. The body portion 60a includes: a base 62; and a laying portion 63 held on the base 62. A recess 621 extending in the extension direction of the pavement surface 60 (i.e., the X-axis direction of the travel direction of the wheel frame 20) is formed on the upper surface of the base 62. The laying portion 63 is formed, for example, by filling the recess 621 with a simulated paving material described later and allowing it to harden. A pavement surface 63a in contact with the test wheel W is formed on the upper surface of the laying portion 63.

[0139] The main body 60a of this embodiment is composed of a main body unit 600a of a pavement unit (a replaceable structure including at least a portion of the pavement 63a), and is detachably mounted on the frame 61. Furthermore, the pavement unit is not limited to the form in which the main body 60a is unitized as in this embodiment (referred to as "main body unit"). It can also be a form in which only the paving section 63 is unitized (referred to as "paving section unit") or a form in which the entire pavement surface 60, including the frame 61, is unitized (referred to as "pavement surface unit").

[0140] The main body 60a of this embodiment is composed of a plurality of main body units 600a that are divided in the extension direction of the pavement surface 60, and the main body units 600a can be replaced individually. Alternatively, the entire main body 60a can be formed as a single replaceable pavement surface unit.

[0141] As in this embodiment, the road surface 60 is formed from road surface units such as the main body unit 600a, and at least a portion of the road surface 63a can be replaced by replacing the road surface unit.

[0142] For example, only the body unit 600a in the central part of the road surface 60 along the extension direction (X-axis direction) can be replaced, and the type of the paving part 63 (e.g., material, structure, surface shape, etc.) can be changed only in the central part. In addition, the type of paving part 63 can be changed for each body unit 600a, for example, the friction coefficient of the road surface 63a can be changed in the extension direction of the road surface 60.

[0143] A recess 622 is provided below the base 62, which engages with the protrusion 612 provided on the frame 61. The main body unit 600a is mounted on the frame 61 by engaging the protrusion 612 and the recess 622, and the two are fixed by bolts and cam linkages (not shown), so that the main body unit 600a is detachably mounted on the frame 61.

[0144] Furthermore, the frame 61 of this embodiment is also formed by a plurality of frame units 610 that divide the frame 61 in the extension direction of the road surface 60, and can be replaced by the units of the frame units 610.

[0145] Furthermore, in this embodiment, the frame unit 610 and the main body unit 600a are of the same length, and the frame unit 610 can also be replaced with the face unit 600 of the main body unit 600a.

[0146] Furthermore, in this embodiment, the paving section 63 is integrally formed with the base 62. However, the paving section 63 can also be configured to be detachable from the base 62. For example, the paving section 63 can be formed by dividing the paving section 63 into a plurality of paving section units 630 in the extension direction of the pavement surface 60, thus creating a paving section 63 that can be replaced unit by unit. In this case, the paving section units 630 and the base unit 620 can be made to the same length, and a composite unit (in other words, a detachable body unit 600a of the paving section 63) can be installed on the base unit 620 for replacement. In addition, a pavement surface unit 600 can be made by assembling the frame unit 610, the base unit 620, and the paving section units 630, and the pavement surface unit 600 can be replaced unit by unit.

[0147] Furthermore, as described above, in this embodiment, a plurality of pavement surface units 600 are connected to form a pavement surface 60. With this configuration, the pavement surface 60 can be lengthened or shortened by adding or removing pavement surface units 600. In addition, by using the same structure for a plurality of pavement surface units, the pavement surface 60 can be manufactured effectively.

[0148] Furthermore, in this embodiment, similar to the pavement surface 60, the track section 10 is also divided into a plurality of track section units 100 in the extension direction. The track section 10 can be lengthened or shortened by adding or deleting track section units 100. The track section units 100 are formed to the same length as the pavement surface 60. Therefore, the length of the track section 10 and the pavement surface 60 can be made the same. In addition, the pavement surface 60 and the track section 10 can also be lengthened, shortened, or partially replaced by a composite unit that integrates the track section units 100 and the pavement surface unit 600.

[0149] In this embodiment, the road surface 60 and the paving section 63 form a simulated asphalt road (i.e., the effect of tire wear on the tire is the same as that of an actual asphalt road). The simulated paving is formed, for example, by adding a binder (adhesive) such as urethane resin or epoxy resin to aggregates containing crushed (if necessary, further processed by grinding or etching) ceramics with excellent wear resistance, such as silicon carbide or alumina, and then hardening it. By using this simulated paving material, a simulated road surface with excellent durability and stable road conditions (i.e., stable wear of the tested tire T) can be obtained. Tire wear can be adjusted, for example, by adjusting the particle size of the aggregate and the amount of binder added.

[0150] The simulated paving in this embodiment is a single-layer structure. However, for example, it is also possible to use multiple layers formed by different materials stacked in the thickness direction for simulated paving. In addition, for example, it is possible to use adjustments to the type and particle size of the aggregate, the type and amount of adhesive, etc., to simulate paving such as stone paving, brick paving, or concrete paving.

[0151] In addition, a road surface 63a with greater (or less) damage to the tires than the actual road surface can be formed. By using a road surface 63a with a greater impact on the tires than the actual road surface, accelerated aging tests of the tires can be conducted.

[0152] In addition, the paving section 63 may also be formed from actual paving materials (e.g., asphalt mixture used for asphalt paving surface layer). Furthermore, not only the outermost layer of the road surface may be formed, but the paving section 63 may also be used to reproduce or imitate the actual paving to the underlying structure.

[0153] Because the road surface 63a does not move during the test, the tire testing device 1 of this embodiment can be tested while foreign objects that affect tire performance (e.g., water, snow, mud, soil, sand, gravel, oil, or simulations thereof) are sprinkled on the road surface 63a. For example, a wet braking test can be performed by testing while water is sprinkled on the road surface 63a.

[0154] Here, a modification of the pavement surface 60 is described. Figure 26 is a cross-sectional view of pavement surface 60A of the modified pavement surface 60. Pavement surface 60A has a frame portion 67 mounted on a base 62. The frame portion 67 is joined to the base 62 in a waterproof manner by means of a joint or the like. It forms a groove 68 together with the base 62 and the paving portion 63. Foreign objects that may affect tire performance (e.g., water, gravel, soil, fallen leaves, etc.) are placed in the groove 68 in a manner that covers the pavement surface 63a. By using the groove 68, foreign objects can be thickly accumulated on the pavement surface 63a. In addition, in this modified example, the frame portion 67 is mounted on the top of the base 62; however, the frame portion 67 may also be mounted on the side of the base 62. Furthermore, the frame portion 67 may also be mounted on the top of the paving portion 63.

[0155] Furthermore, the pavement surface 60A is equipped with a temperature adjustment means 64 for adjusting the temperature of the pavement surface 63a. The temperature adjustment means 64 of this modified example includes: a flow path 64a embedded in a base 62; a temperature sensor 64b for detecting the temperature of the pavement surface 63a; and a temperature adjustment device 64c (FIG. 38). The temperature sensor 64b is, for example, a contact temperature sensor such as a thermocouple or a thermistor, or a non-contact temperature sensor such as an infrared sensor. The temperature adjustment device 64c is connected to a control unit 72 and adjusts the temperature of the pavement surface 63a to a set temperature according to instructions from the control unit 72. Specifically, the temperature adjustment device 64c adjusts the temperature of a heat transfer medium (e.g., oil or water containing antifreeze) based on the detection result of the temperature sensor 64b and sends the heat transfer medium to the flow path 64a. By allowing the heat transfer medium, whose temperature has been adjusted by the temperature adjustment device, to flow into the flow path 64a, the pavement surface 63a can be adjusted to a specified temperature. In addition, in order to stabilize the temperature of the road surface 63a and improve the heat utilization efficiency, the surface of the base 62 is covered by heat insulation material 69.

[0156] The temperature adjustment means 64 can adjust the temperature of the road surface 63a over a wide range from low temperature (e.g., -40°C) to high temperature (e.g., 80°C). By accumulating water in the trough 68, the set temperature of the road surface 63a can be set below the freezing point to form a frozen road surface. That is, by using the road surface 60A of this modified example, an ice braking test can be performed. In addition, a snow braking test can be performed with snow poured into the trough 68.

[0157] The flow path 64a is formed parallel to the road surface 63a and meanders within the base 62 at equal intervals. Furthermore, the base 62 is divided into a plurality of blocks (base units 620) in its extending direction, each block having an individual flow path 64a. This configuration allows for a more uniform temperature across the entire road surface 63a.

[0158] Next, the load detection unit 165 will be explained. The load detection unit 165 is a component that can detect the load distribution applied to the tire tread.

[0159] Figures 27 and 28 are top and right side views of the load detection unit 165 of the road surface 60 and its surrounding area, respectively. In addition, Figures 29-31 are front, right and top views of the load detection unit 165, respectively.

[0160] As shown in Figures 27 and 28, a recess 60p that is elongated in the Y-axis direction is formed on the upper surface of the main body 60a of the pavement surface 60. The load detection unit 165 is housed in the recess 60p and fixed to the bottom surface of the recess 60p.

[0161] As shown in Figures 29-31, the load detection unit 165 includes: a fixed frame 1658, a movable frame 1659, a pair of linear guide rails 1654, a sensor array unit 1650, a moving unit 1655, and a sensor position detection unit 1656. In Figure 29, the track support portion 1658b of the linear guide rails 1654 and the fixed frame 1658 is omitted. The movable frame 1659 is movable in the Y-axis direction (i.e., the width direction of the pavement surface 60) by means of the pair of linear guide rails 1654. The sensor array unit 1650 is mounted on the movable frame 1659. Details of the sensor array unit 1650 will be described later.

[0162] Figure 32 is a top view showing the state of the movable part (i.e., the movable frame 1659 and the sensor array unit 1650) of the disassembled load detection unit 165.

[0163] As shown in Figures 30 and 32, the mounting bracket 1658 includes: a generally rectangular base plate 1658a; and a pair of track support portions 1658b fixed to the base plate 1658a. The pair of track support portions 1658b face the Y-axis direction and are arranged in the length direction at intervals in the X-axis direction.

[0164] The linear guide 1654 includes: a track 1654a extending in the Y-axis direction; and a plurality of wheel carriers 1654b (hereinafter referred to as "movers 1654b") capable of traveling on the track 1654a. The track 1654a is mounted on top of the track support 1658b. Furthermore, the movers 1654b are mounted on the bottom of the movable frame 1659. The movable frame 1659 is guided to move in the Y-axis direction by the linear guide 1654.

[0165] The moving unit 1655 is disposed between a pair of track support portions 1658b and a linear guide rail 1654. The moving unit 1655 includes a motor 1655m and a ball screw 1655b. The ball screw 1655b includes a screw shaft 1655ba, a nut 1655bb, a bearing portion 1655bc, and a bearing portion 1655bd. In this embodiment, the motor 1655m is a servo motor; however, other types of motors with controllable workload can also be used as the motor 1655m.

[0166] The helical shaft 1655ba is rotatably supported at both ends by a pair of bearings 1655bc and 1655bd. Furthermore, one end of the helical shaft 1655ba is connected to the shaft of the motor 1655m. A nut 1655bb, which engages with the helical shaft 1655ba, is mounted below the movable frame 1659. When the helical shaft 1655ba is rotated by the motor 1655m, the movable frame 1659 and the sensor array unit 1650 move together with the nut 1655bb in the Y-axis direction. That is, the position of the sensor array unit 1650 in the Y-axis direction can be changed by the rotational drive of the motor 1655m.

[0167] As shown in FIG32, the sensor position detection unit 1656 includes: a movable arm 1656a, a plurality of proximity sensors 1656c (three in this embodiment), and a sensor mounting part 1656b. The end portion of the movable arm 1656a is fixed to a movable frame 1659 and can move together with the movable frame 1659 in the Y-axis direction. The sensor mounting part 1656b is mounted on a fixed frame 1658.

[0168] A plurality of proximity sensors 1656c have their detection surfaces 1656cf facing the positive X-axis direction and are arranged at intervals (e.g., equal intervals) in the Y-axis direction, and are mounted on the sensor mounting portion 1656b.

[0169] A proximity portion 1656ap, adjacent to the proximity sensor 1656c, is formed at the front end of the movable arm 1656a. In this embodiment, the proximity portion 1656ap is formed by bending the front end of the movable arm 1656a into a crank shape. The proximity portion 1656ap is positioned at the same height as the detection surfaces 1656cf of the plurality of proximity sensors 1656c. Furthermore, the detection surfaces 1656cf of the plurality of proximity sensors 1656c are spaced apart within the range of motion of the proximity portion 1656ap in the Y-axis direction.

[0170] Figure 33 is an enlarged view of the region E enclosed by the two-point chain line in Figure 29. As shown in Figures 29 and 33, the sensor array unit 1650 includes: a frame 1650a and a plurality of (150 in this embodiment) load detection modules 1650m. A recess 1650ap, which is elongated in the Y-axis direction, is formed in the center of the upper part of the frame 1650a. The plurality of load detection modules 1650m are housed in the recess 1650ap and fixed to the bottom surface of the recess 1650ap.

[0171] A plurality of load detection modules 1650m are arranged in a grid pattern at equal intervals (e.g., without gaps) in both the X-axis and Y-axis directions. In this embodiment, 150 load detection modules 1650m are arranged in 5 columns in the X-axis direction and 30 columns in the Y-axis direction.

[0172] The load detection module 1650m includes: a three-component force sensor 1651, a laying section 1652, and a bolt 1653. The three-component force sensor 1651 is a cylindrical piezoelectric element with its central axis pointing towards the Z-axis. The laying section 1652 is, for example, a cubic member formed from the same simulated laying material or laying material as the laying section 63, with equal lengths in the X-axis and Y-axis directions. Furthermore, the shapes of the three-component force sensor 1651 and the laying section 1652 are not limited to these shapes. For example, the shape of the three-component force sensor 1651 may also be cubic, and the shape of the laying section 1652 may also be cylindrical.

[0173] A through hole 1651b in the Z-axis direction is formed in the center of the cylindrical three-component force sensor 1651. Furthermore, a bolt hole 1652b extending in the Z-axis direction is formed in the center of the laying section 1652. The load detection module 1650m is integrated and fixed to the frame 1650a by bolts 1653 that are screwed into the bolt hole 1652b of the laying section 1652 through the hole 1651b of the three-component force sensor 1651. A road surface 1652a is formed on the top of the laying section 1652 by horizontally arranging the load detection modules 1650m at the same height. The areas in the X and Y axes where the load detection modules 1650m are arranged become the detection area of ​​the sensor array unit 1650. In addition, the width (i.e., the length in the Y-axis direction) Ly (Figure 31) of the detection area of ​​the sensor array unit 1650 is much wider than the tread of the test tire T, and the full width of the tire tread of the test tire T can contact the road surface 1652a.

[0174] The following three forces, fR, fT, and fL, applied to the road surface 1652a (i.e., the tire tread) by each load detection module 1650m are detected by the three-component force sensor 1651: a) Radial force fR b) Tangential force fT c) Lateral force fL

[0175] The load detection unit 165 can be used to detect the distribution and time variation of the force received by the road surface from the tire tread of the test tire T (that is, the force applied to the tire tread).

[0176] Figure 38 is a schematic block diagram showing the configuration of the control system 1a of the tire testing device 1. The control system 1a includes: a control unit 72 that controls the operation of the entire device; a measuring unit 74 that performs various measurements; and an interface 76 that exchanges inputs and outputs with the outside.

[0177] The control unit 72 is connected to the motors 141 of each drive unit 14, the motor 32 of the torque imparting device 30, the motor 431 of the load adjustment unit 42, the motor 451 of the tilt adjustment unit, the motor 471 of the slip angle adjustment unit 46, and the motor 1655m of the moving unit 1655 via drive wheels 141a, 32a, 431a, 451a, 471a, and 1655a. Furthermore, the control unit 72 is connected to the temperature adjustment device 64c.

[0178] The control unit 72 is communicatively connected to each of the drive wheels 141a, 32a, 431a, 451a and 471a via optical fiber, enabling high-speed feedback control between the control unit 72 and each drive wheel. This allows for more precise (high resolution and high accuracy on the time axis) synchronous control.

[0179] The measurement unit 74 is connected to the six-component force sensor 54 of the spindle unit 50, the three-component force sensor 1651 of the load detection unit 165, and the proximity sensor 1656c of the sensor position detection unit 1656 via amplifiers 54a, 1651a, and 1656ca, respectively. Signals from the six-component force sensor 54, the three-component force sensor 1651, and the proximity sensor 1656c are amplified by amplifiers 54a, 1651a, and 1656ca, respectively, and then converted into digital signals in the measurement unit 74 to generate measurement data. The measurement data is input to the control unit 72. Furthermore, in Figure 38, only one of each of the three-component force sensor 1651, amplifier 1651a, proximity sensor 1656c, and amplifier 1656ca is shown.

[0180] The phase information of the rotary encoder RE built into each motor 141, 32, 431, 451, 471 and 1655m is detected and input to the control unit 72 via each drive wheel 141a, 32a, 451a, 471a and 1655a respectively.

[0181] Interface 76 includes, for example, one or more user interfaces for input / output with the user, network interfaces for connecting to various networks such as LAN (Local Area Network), and communication interfaces such as USB (Universal Serial Bus) and GPIB (General Purpose Interface Bus) for connecting to external devices. Furthermore, the user interface may include, for example, one or more input / output devices such as various operation switches, displays, LCD (Liquid Crystal Display) and other display devices, various indicator devices such as mice and touch panels, touch screens, cameras, printers, scanners, buzzers, speakers, microphones, and memory card readers / writers.

[0182] The control unit 72 synchronously controls the motors 141 of each drive unit 14 based on the speed setting data input through the interface 76, so that the wheel frame 20 can travel at a specified speed. In addition, in this embodiment, all four drive units 14 are driven in the same phase (more precisely, the drive units 14LA and 14LB on the left side are driven in opposite phase [opposite rotation] to the drive units 14RA and 14RB on the right side).

[0183] Furthermore, the control unit 72 controls the drive of the motor 32 of the torque application device 30 by using the setting data of the front and rear forces (braking force or driving force) to be applied to the test tire T obtained through the interface 76, thereby applying a specified front and rear force to the test tire T. In addition, the control unit 72 can also apply a specified torque to the test wheel W by using the torque setting data (or acceleration setting data) instead of the front and rear force setting data to control the torque application device 30.

[0184] The control unit 72 can control the drive unit 14 that drives the wheel frame 20 at a specified driving speed (while the test tire T rotates at a speed approximately the same as the driving speed) in sync with the synchronization signal; and control the torque applicator 30 that applies front and rear force (or torque) to the test tire T.

[0185] In addition to basic waveforms such as sine wave, half sine wave, sawtooth wave, triangular wave, and trapezoidal wave, the waveform of the torque generated in the torque imparting device 30 may also use the waveform of the front and rear force (or torque) measured in the road test, the waveform of the front and rear force (or torque) obtained by simulation calculation, or other arbitrary synthetic waveforms (e.g., waveforms generated by function generator, etc.).

[0186] In addition to the basic waveform, the control of the travel speed of the wheel frame 20 (or the number of revolutions of the test wheel W) can also use the waveform of the number of revolutions of the wheel measured in the road test, the waveform of the speed change obtained by simulation calculation, or other arbitrary synthetic waveforms (e.g., waveforms generated by function generator).

[0187] Next, the steps for changing the position of the sensor array unit 1650 in the Y-axis direction by means of the moving unit 1655 will be explained. In the initial state shown in FIG32, the sensor array unit 1650 has the approach portion 1656ap of the movable arm 1656a positioned opposite the detection surface 1656cf of the central proximity sensor 1656c. For example, when a user operates the touch screen and instructs the sensor array unit 1650 to move to the left (positive Y-axis direction), the control unit 72 sends a counterclockwise rotation command to the drive wheel 1655a, causing the sensor array unit 1650 to move in the positive Y-axis direction. The drive wheel 1655a, having received the counterclockwise rotation command, supplies the motor 1655m with a drive current for counterclockwise rotation. Then, when the motor 1655m is driven counterclockwise by the drive current, the helical shaft 1655ba rotates counterclockwise together with the shaft of the motor 1655m, and the sensor array unit 1650 moves together with the nut 1655bb and the movable bracket 1659 in the positive Y-axis direction.

[0188] When the sensor array unit 1650 moves in the positive Y-axis direction, the approach portion 1656ap of the movable arm 1656a moves away from the detection surface 1656cf of the central proximity sensor 1656c, and the central proximity sensor 1656c cannot detect the approach. Soon after, the approach portion 1656ap of the movable arm 1656a reaches a position opposite to the detection surface 1656cf of the left (positive Y-axis direction side) proximity sensor 1656c. At this time, the left proximity sensor 1656c detects the approach and outputs a proximity signal indicating that the approach has been detected. The measuring unit 74, which receives the proximity signal via the amplifier 1656ca, notifies the control unit 72 that the sensor array unit 1650 has reached the designated position on the left. Upon receiving the notification from the measuring unit 74, the control unit 72 sends a drive stop command to the drive wheel 1655a. Upon receiving the drive stop command, the drive wheel 1655a stops supplying drive current to the motor 1655m. In this way, the shaft of motor 1655m and screw shaft 1655ba stop rotating, the nut 1655bb and sensor array unit 1650 also stop, and the movement of sensor array unit 1650 is completed.

[0189] By using the moving unit 1655, the length Ly (Fig. 31) of the detection area of ​​the sensor array unit 1650 in the Y-axis direction is shortened, which can reduce the number of load detection modules 1650m required for measuring load distribution and reduce the cost of manufacturing and maintaining the sensor array unit 1650.

[0190] Next, a method for obtaining the load distribution applied to the tire tread using the load detection unit 165 will be explained. Figure 34 is a flowchart showing the steps of the method for obtaining the load distribution applied to the tire tread.

[0191] When the power switch of the tire testing device 1 is turned on, the control unit 72 first performs an initialization process S1. As shown in FIG1, in the initial state, the wheel carrier 20 is positioned at an initial position (initial driving position) PX0 near the end of the negative X-axis direction of its range of motion. In addition, the lifting frame 421 (FIG. 19) is positioned at an initial position PZ0 near, for example, the upper end of its range of motion. At the initial position PZ0, the test wheel W is lifted from the road surface 63a, and the test wheel W can be loaded, unloaded, and aligned. Furthermore, the camber adjustment unit 44 and the slip angle adjustment unit 46 are adjusted to values ​​set for camber and slip angle, respectively.

[0192] With the test wheel W floating off the road surface 63a, the motor 32 of the drive torque application device 30 moves the rotational position θW of the test wheel W to the initial rotational position θW0, and the initialization process S1 is completed. Furthermore, the rotational position θH of the torque application device 30 itself (i.e., the rotating frame 31) is determined by the travel position PX of the wheel frame 20. In the initial state, the torque application device 30 is always positioned at the initial rotational position θH0.

[0193] After the initialization process S1 is completed, for example, when the user operates the touch screen to give an instruction to start the test (S2: YES), the measurement setting (Set) number k of the counter is reset to 1 (S3). Then, the test wheel W is lowered by the load adjustment unit 42 and contacts the road surface 63a, and the set load is applied (S4).

[0194] Next, the first measurement setting S5 is performed. Measurement setting S5 involves driving the motors 141 of each drive unit 14, causing the wheel frame 20 to travel at a set travel speed, and the test wheel W to rotate at a circumferential speed approximately the same as the travel speed of the wheel frame 20. In addition, the motor 32 of the drive torque application device 30 is driven, and the set torque is applied to the test wheel W.

[0195] In the measurement setting S5, the forces applied to the road surface 1652a and the test wheel W are detected at specified time intervals (e.g., 5 millisecond intervals) by the 3-component force sensor 1651 of the load detection unit 165 and the 6-component force sensor 54 of the main shaft unit 50, respectively. In addition, the time interval detected by the 3-component force sensor 1651 and the 6-component force sensor 54 must be appropriately set according to the test conditions (e.g., the travel speed of the wheel frame 20 and the necessary test accuracy).

[0196] Furthermore, in the measurement setting S5, the travel position PX of the wheel frame 20 and the rotational position θW of the test wheel W are calculated at a specified time interval (for example, the same time interval as the detection by the three-component force sensor 1651). The travel position PX of the wheel frame 20 is calculated from the detection result of the rotary encoder RE (FIG. 38) of the motor 141 built into the drive unit 14, the reduction ratio of the belt mechanism 142, and the pitch circle diameter of the drive pulley 152 of the belt mechanism 15. In addition, in the description of this embodiment, the travel position PX of the wheel frame 20 is defined as the position of the rotation axis AY of the test wheel W in the travel direction (X-axis direction).

[0197] The rotational position θW of the test wheel W is calculated based on the detection results of the rotary encoder 38 of the torque-applying device 30 and the rotary encoder RE built into the motor 32. Specifically, the rotational position θW of the test wheel W is calculated by multiplying the rotational position θM of the shaft 321 of the motor 32 detected by the rotary encoder RE of the motor 32 (however, the initial rotational position θM0 is 0 [rad] in the initial state) by the reduction ratio of the reducer 33 (that is, the rotational position θS of the shaft 34 relative to the rotating frame 31), and adding the rotational position θH of the rotating frame 31 of the torque-applying device 30 detected by the rotary encoder 38.

[0198] Alternatively, a detection means such as a rotary encoder may be configured to detect the rotational position θT output from the torque imparting device 30 (e.g., the rotational device of the main shaft 52 or the drive shaft 261, 266), and the rotational position θW of the test wheel W may be directly detected by the detection means.

[0199] The detection results of the three-component force sensors 1651 and 6-component force sensors 54, which are detected at the same time by the rotary encoder RE built into the motor 141 of the drive unit 14 (i.e., the travel position PX of the wheel frame 20) and the rotational position θW of the test wheel W, are stored in the memory device 721 of the control unit 72 (or, for example, a memory means accessible by the control unit 72 such as a server 77 connected to the control unit 72 via LAN). Furthermore, the detection results of the three-component force sensors 1651 can also be configured to record only the period during which the test wheel W passes through the sensor array unit 1650 and a specified period before and after it. This reduces the amount of data stored.

[0200] When the wheel carrier 20 reaches the end of the travel section and stops, the test wheel W is raised by the load adjustment unit 42 to the height above the road surface 63a (for example, the same height as the initial state) (S6). Then, the drive unit 14 is driven, and the wheel carrier 20 moves to the initial position PX0.

[0201] Before the set number k reaches the specified number of times n, the above processes S4 to S9 (S8) are repeated. When the set number k has not reached the specified number of times n (S8: No), the motor 32 of the drive torque imparting device 30 moves the rotation position θW of the test wheel W to the rotation position θW0 + k * ΔθW (S9), and the counter k increases (S12). That is, for each increase of the set number k, the rotation position θW of the test wheel W at the initial position PX0 changes by an angle width ΔθW.

[0202] The angle width ΔθW is, for example, set to a value below the center angle θC1 (i.e., the rotation angle θC1 when the test wheel W rotates a distance LX) of the detection area of ​​the sensor array unit 1650 in the X-axis direction (Fig. 30). For example, the angle width ΔθW is set to the same value as or slightly smaller than the center angle θC2 of the test wheel W corresponding to the configuration interval δ (Fig. 30) of the load detection module 1650m.

[0203] In addition, the angle width ΔθW can also be set to, for example, 2π divided by a specified number of times n. In this case, the entire circumference of the test wheel W is measured by setting n measurements.

[0204] When the measurement setting of the specified number of times n is completed (S8: Yes), the load profile calculation is then performed S10.

[0205] Figure 35 is a flowchart showing the steps of load profile calculation S10. Load profile calculation S10 is the processing of load profile data based on the measurement results obtained by setting S5 through n measurements.

[0206] Load profile data is data that corresponds to the values ​​of the three forces applied to the tire (i.e., radial force fR, tangential force fT and lateral force fL) and the plane coordinates on the road surface.

[0207] In the load profile calculation S10, firstly, the coordinates of each load detection module 1650m are calculated (S101). In addition, in this embodiment, the coordinates of the central point on the load detection module 1650m are defined as the coordinates of the load detection module 1650m.

[0208] Figure 36 shows the positional relationship between the load detection module 1650m and the rotation axis AY of the test wheel W. As described above, in this embodiment, 150 load detection modules 1650m are arranged in 5 columns in the X-axis direction and 30 columns in the Y-axis direction. In the following description, the column number of the load detection module 1650m in the X-axis direction is designated as p, and the column number in the Y-axis direction is designated as q. The configuration of the load detection module 1650m is represented by a pair of positive integers [p, q] (hereinafter referred to as "number [p, q]").

[0209] Furthermore, the (x, y) coordinate system is used in the load profile calculation S10. The (x, y) coordinate system is a two-dimensional orthogonal coordinate system with the center of the load detection module 1650m located at number [3, 1] as the origin and parallel to the (x, y) coordinate system. That is, the xy plane is the plane of road surfaces 63a and 1652a of the road surface 60. In addition, in this embodiment, the origin of the (x, y) coordinate system (that is, the position of the load detection module 1650m at number [3, 1]) is defined as the position of the sensor array unit 1650. In addition, in the following description, the coordinates with a fixed point as the origin are called absolute coordinates, and the coordinates with a moving point as the origin are called relative coordinates. In the load profile calculation S10, the absolute coordinates of each load detection module 1650m are calculated.

[0210] In this embodiment, the load detection modules 1650m are arranged at equal intervals δ in the x-axis and y-axis directions, respectively. Therefore, the xy coordinates of the numbers [p, q] are calculated by the following formulas: x = (p - 3) * δ y = (q - 1) * δ

[0211] Next, calculate the x-coordinate (hereinafter referred to as "coordinate xAY") of the rotation axis AY of the test wheel W. (S102) The coordinate xAY is calculated by the following formula: xAY = PX - SX Where, PX: X-coordinate of the travel position PX (rotation axis AY) of the test wheel W; SX: X-coordinate of the origin of the (x, y) coordinate system.

[0212] That is, in step S102, the coordinates of the rotation axis AY of the test wheel W are transformed from the XY coordinate system to the xy coordinate system.

[0213] Next, the relative position (relative coordinates) of the load detection module 1650m is calculated using the travel position PX (rotation axis AY) of the test wheel W as a reference (S103). The relative coordinates (xr, yr) of the load detection module 1650m are calculated using the following formulas. In this embodiment, load profile data with respect to the relative coordinates of the rotation axis AY are obtained. xr = x - xAY yr = y

[0214] Next, by averaging all the measured results at each relative coordinate (xr, yr) (that is, by measuring the radial force fR, tangential force fT, and transverse force fL measured by each load detection module 1650m), load profile data for the three forces fR, fT, and fL are calculated (S104). In processing S104, the load profile data can also be calculated as an approximate surface obtained by regression analysis (e.g., surface fitting using the least quadratic method).

[0215] In processing S104, the rotational position θW of the test wheel W (i.e., each rotational position θW) can also be considered to calculate the load profile data. Furthermore, the symmetry of the tire tread pattern of the test tire T around the rotation axis AY can also be included to calculate the load profile data. Specifically, the load profile data can also be calculated for each rotational position θW that is in phase in the circumferential period of the tire tread pattern.

[0216] Furthermore, in this embodiment, the measurement is performed only on one revolution of the test wheel W through n measurement settings. However, the measurement settings can be further increased to perform measurements on multiple revolutions. In addition, because this embodiment changes the rotation position θW of the test wheel W at the initial position PX0 by changing the center angle θC2 of each test wheel W corresponding to the arrangement interval δ of the load detection module 1650m, and performs multiple measurement settings, the resolution of the load profile data in the x-axis direction becomes the level of the arrangement interval δ of the load detection module 1650m. Furthermore, by changing the rotation position θW by small angles (e.g., 1 / 10 of the center angle θC2) and repeatedly performing measurement settings, the actual resolution in the x-axis direction can be finer than the arrangement interval δ of the load detection module 1650m. For example, when changing the rotation position θW by 1 / m of each center angle θC2 (however, m is a natural number) and repeatedly performing measurement settings, the actual resolution in the x-axis direction can be reduced to the level of δ / m.

[0217] In this embodiment, the length LX (Fig. 30) of the detection area of ​​the sensor array unit 1650 in the X-axis direction is shorter than the length of the tire tread in the X-axis direction. Therefore, by only rotating the test wheel W once on the sensor array unit 1650, it is impossible to obtain the load distribution of the entire tire tread.

[0218] Therefore, this embodiment employs a method that staggers the rotational position θW of the test wheel W when it rotates on the sensor array unit 1650, and measures the load distribution on the tire tread multiple times. This shortens the length of the detection area of ​​the sensor array unit 1650 in the X-axis direction, reduces the number of load detection modules 1650m required for load distribution measurement, and also reduces the manufacturing and maintenance costs of the sensor array unit 1650.

[0219] Furthermore, by changing the Y-axis position of the sensor array unit 1650 at specified intervals and repeatedly performing measurement settings by the motion unit 1655, the actual resolution in the Y-axis direction can be reduced. At this time, the motor 1655m of the motion unit 1655 uses a position-controllable motor (e.g., a servo motor or a stepper motor). For example, by changing the Y-axis position of the sensor array unit 1650 every 1 mm and repeatedly performing measurement settings, the actual resolution in the Y-axis direction can be reduced to about 1 mm.

[0220] Next, the load profile image, created based on the calculated load profile data, is displayed on the display device of the interface 76, thereby visualizing the load distribution applied to the tire tread (S11). Figure 37 shows an example of the load profile image display. Figure 37(a) shows the load profile image of the tangential force fT, Figure 37(b) shows the lateral force fL, and Figure 37(c) shows the load profile image of the radial force fR. The load profile image shown in Figure 37 is a conversion of the force values ​​at each position (xr, yr) into brightness. In addition, the form of the load profile image is not limited to this embodiment; for example, it can also be another form such as a stereoscopic CG image.

[0221] The above is a description of the embodiments of the present invention. The embodiments of the present invention are not limited to those described above, and various modifications can be made. For example, the structure of the embodiments illustrated in this specification and / or the description in this specification, and the structure of the embodiments that will be apparent to those skilled in the art, are also included in the embodiments of this application.

[0222] The tire testing device 1 is configured in the above embodiment to have two belt mechanisms 15, but it may also have one or more belt mechanisms 15.

[0223] The belt mechanism 15 is driven by the power generated by a pair of drive units 14 in the above embodiment, but it can also be driven by one or more drive units 14.

[0224] In the above embodiments, toothed belts and toothed pulleys are used in each of the belt mechanisms 15, 24, and 25. However, for one or more belt mechanisms, flat belts, V-belts, or V-rib belts with a plurality of V-shaped ribs arranged in the width direction may be used instead of toothed belts. In addition, general-purpose belts with twisted glass fiber cores may also be used. Furthermore, other types of winding transmission mechanisms such as chain drive mechanisms or wire drive mechanisms, or other types of power transmission mechanisms such as ball screw mechanisms, gear drive mechanisms, or hydraulic mechanisms may be used instead of each belt mechanism.

[0225] In the above embodiment, the power to drive the wheel frame 20 and the power to drive the test wheel W (main shaft 52) ​​are supplied by a common drive unit 14 and transmitted by a common belt mechanism 15. However, the present invention is not limited to this configuration. For example, it is also possible to generate the power to drive the wheel frame 20 and the power to drive the test wheel W by separate drive units and transmit them by separate power transmission means (e.g., separate belt mechanisms). In this case, in order to adjust the travel speed of the wheel frame 20 and the circumferential speed of the test wheel W, it is necessary to synchronously control the drive units for driving the wheel frame and the drive units for driving the test wheel.

[0226] In the above embodiment, a simple drive system and control system are achieved by combining a portion (drive unit 14 and belt mechanism 15) of the mechanism for driving the wheel frame 20 (wheel frame drive means) and the mechanism for driving the test wheel W (test wheel drive mechanism). The combination of the wheel frame drive means and the test wheel drive means (especially the combination of drive unit 14) reduces the load on drive unit 14 by introducing torque imparting device 30, which separates the power sources for speed control and torque control of test wheel W.

[0227] The above embodiment uses the right-side drive units 14RA and 14RB as both wheel frame drive means and rotational motion supply means, while the left-side drive units 14LA and 14LB function as wheel frame drive means. However, the present invention is not limited to this configuration. For example, the left-side drive units 14LA and 14LB can also be configured to function as both wheel frame drive means and rotational motion supply means, while the right-side drive units 14RA and 14RB function as wheel frame drive means. Furthermore, both the left-side drive units 14LA and 14LB and the right-side drive units 14RA and 14RB can be configured to function as both wheel frame drive means and rotational motion supply means. This configuration can be achieved, for example, by using a total of two shafts 223B connecting the first driven units 22 and 22L (in other words, replacing them with a single long shaft 223B connecting the left and right first driven units 22 and 22L).

[0228] The third modification described above can measure the load profile of a tire tread longer than the length LX of the detection area of ​​the sensor array unit 1650 in the X-axis direction by changing the rotational position θW of each test wheel W set at the initial position PZ0. However, by setting a means to change the position of the sensor array unit 1650 in the X-axis direction, the load profile of a tire tread longer than the length LX cannot be measured by changing the rotational position θW of each test wheel W set at the initial position PZ0. The means to change the position of the sensor array unit 1650 in the X-axis direction can be configured, for example, similar to the moving unit 1655, by a position-controllable motor and a feed screw mechanism (e.g., a ball screw mechanism).

[0229] In the above embodiment, the guide mechanism 12 of the track section 10 is supported by a pair of single-row bearings 127a and other support rods 124a, etc. However, the present invention is not limited to this configuration. For example, it may also be supported by one or more rows or a single row of bearings.

[0230] In the above embodiment, a heat-treated rail is used in the guide mechanism 12 of the rail section 10. However, the present invention is not limited to this configuration. For example, ordinary rails (JIS E 1101:2001) or lightweight rails (JIS E 1103:1993) may also be used. Furthermore, it is not limited to flat-bottomed rails; other shapes of rails such as double-headed rails, bull-headed rails, and bridge-shaped rails may also be used.

[0231] In the above embodiment, the drive unit 14 uses a motor 141 (AC servo motor). However, the present invention is not limited to this configuration. Instead of the AC servo motor, other types of motors that can be speed-controlled or position-controlled (e.g., DC servo motors, so-called converter motors that combine converter circuits with AC motors or brushless motors) can also be used.

[0232] In the above embodiment, the torque imparting device 30, the load adjustment unit 42, and the slip angle adjustment unit 46 are respectively equipped with AC servo motors 32, 451, and 461. However, the present invention is not limited to this configuration. Alternatively, other types of motors capable of position control (e.g., DC servo motors or stepper motors) may be used instead of AC servo motors. [Simplified Explanation of the Diagram]

[0021] Figure 1 is a right side view of a tire testing device according to an embodiment of the present invention. Figure 2 is a top view of a tire testing device according to an embodiment of the present invention. Figure 3 is a rear view of a tire testing device according to an embodiment of the present invention. Figure 4 is an enlarged view (right side view) of a tire testing device according to an embodiment of the present invention. Figure 5 is an enlarged view (top view) of a tire testing device according to an embodiment of the present invention. Figure 6 shows the configuration of the guide mechanism. Figure 7 is a cross-sectional view of the guide mechanism (Type A). Figure 8 is a cross-sectional view of the guide mechanism (Type B). Figure 9 shows the connection part of the track component. Figure 10 is a block diagram showing the schematic logic structure of the drive system. Figure 11 is a schematic mechanical structure diagram showing the main parts of the drive system. Figure 12 is a schematic structural diagram showing the drive part and the drive pulley part. Figure 13 is a top view of the first driven part. Figure 14 is a cross-sectional view along line A-A of Figure 13. Figure 15 is a cross-sectional view along line B-B of Figure 13. Figure 16 is a cross-sectional view along line C-C of Figure 13. Figure 17 is a cross-sectional view of the second driven part. Figure 18 is a cross-sectional view of the torque-imparting part. Figure 19 is a schematic structural diagram showing the alignment part 40. Figure 20 is a view in the direction of arrow A-A in Figure 19. Figure 21 is a view in the direction of arrow B-B in Figure 19. Figure 22 is a view in the direction of arrow C-C in Figure 19. Figure 23 is a view in the direction of arrow D-D in Figure 19. Figure 24 is a schematic structural diagram showing the main shaft part. Figure 25 is a cross-sectional view of the road surface. Figure 26 is a cross-sectional view of a modified example of the road surface. Figure 27 is a top view near the load detection part of the road surface. Figure 28 is a side view near the load detection part of the road surface. Figure 29 is a front view of the load detection part. Figure 30 is a side view of the load detection part. Figure 31 is a top view of the load detection part. Figure 32 is a top view showing the state of the movable part of the load detection part being disassembled. Figure 33 is an enlarged view of area E in Figure 18. Figure 34 is a flowchart illustrating the steps for obtaining the load distribution applied to the tire tread. Figure 35 is a flowchart illustrating the steps for calculating the load profile. Figure 36 is a top view showing the configuration of the load detection module and the rotation axis of the test wheel. Figure 37 is an example of a load profile. Figure 38 is a block diagram showing the general structure of the control system.

Claims

1. A tire testing apparatus comprising: a road surface; and a wheel frame rotatably holding a test wheel on which a test tire is mounted, and capable of traveling along the road surface while the test tire is in contact with the road surface; the wheel frame comprising: an axle portion rotatably supporting the test wheel; and an alignment portion for adjusting the wheel alignment of the test wheel by changing the direction of the axle portion; the alignment portion comprising a load adjustment portion for adjusting the load applied to the test wheel by changing the height of the axle portion; the load adjustment portion comprising: a first movable frame for vertically movable support; a linear guide rail for guiding the vertical movement of the first movable frame; and a first drive unit for vertically driving the first movable frame, wherein the alignment portion comprises a camber adjustment portion for adjusting the camber angle of the test wheel, the camber adjustment portion comprising: The second movable frame is rotatably supported around an Eϕ axis parallel to the travel direction of the aforementioned wheel frame; and the ϕ drive unit rotates and drives the aforementioned second movable frame around the aforementioned Eϕ axis, wherein the aforementioned tilt adjustment part has a curved guide rail, which guides the rotation of the aforementioned second movable frame.

2. The tire testing apparatus of claim 1, wherein the aforementioned linear guide rail comprises: a track; and a first traveling part that can travel on the aforementioned track; either the aforementioned track or the aforementioned first traveling part is fixed to the aforementioned first movable frame.

3. The tire testing apparatus of claim 1, wherein the aforementioned wheel frame has a main frame, which is a small house-shaped alignment mechanism support that houses the aforementioned alignment part.

4. The tire testing device of claim 1, wherein the other side of the aforementioned track and the aforementioned first traveling unit is fixed to the aforementioned alignment mechanism support.

5. The tire testing apparatus of claim 1, wherein the cross-section of the first movable frame and the second movable frame cut off on a plane orthogonal to the rotation axis of the test wheel is slightly inverted U-shaped, and the curved guide rail is disposed between the inner sides of the slightly inverted U-shape of the first movable frame and the outer sides of the slightly inverted U-shape of the second movable frame.

6. The tire testing apparatus of claim 3 or 4, wherein the cross-section of the aforementioned alignment mechanism support portion cut in a plane orthogonal to the rotation axis of the aforementioned test wheel is slightly inverted U-shaped, and the aforementioned linear guide rail is disposed between the inner sides of the two sides of the slightly inverted U-shape of the aforementioned alignment mechanism support portion and the outer sides of the two sides of the slightly inverted U-shape of the aforementioned first movable frame.

7. The tire testing apparatus of claim 1, wherein the aforementioned camber adjustment part comprises: a cylindrical first pivot, which is coaxially arranged with the aforementioned Eϕ axis; and a first bearing, which rotatably supports the aforementioned first pivot; either the aforementioned first pivot or the aforementioned first bearing is fixed to the aforementioned second movable frame.

8. The tire testing apparatus of claim 5, wherein the other side of the aforementioned first pivot and the aforementioned first bearing is fixed to the aforementioned first movable frame.

9. The tire testing apparatus of claim 1, wherein the aforementioned curved guide rail comprises: an arc-shaped curved track, which is concentrically arranged with the aforementioned Eϕ axis; and a second traveling part, which can travel on the aforementioned curved track; either the aforementioned curved track or the aforementioned second traveling part is fixed to the aforementioned second movable frame.

10. The tire testing apparatus of claim 1, wherein the aforementioned alignment part includes a slip angle adjustment part, which is capable of adjusting the slip angle of the aforementioned test wheel, the aforementioned slip angle adjustment part including: a third movable frame, which is rotatably supported around an Eθ axis that is orthogonal to the Eλ axis and the Eϕ axis of the aforementioned test wheel rotation axis respectively; and an θ drive unit, which is driven to rotate around the aforementioned Eθ axis of the aforementioned third movable frame.

11. The tire testing apparatus of claim 8, wherein the aforementioned slip angle adjustment unit comprises: a cylindrical second pivot arranged coaxially with the aforementioned Eθ axis; and a second bearing rotatably supporting the aforementioned second pivot; either the aforementioned second pivot or the aforementioned second bearing is fixed to the aforementioned third movable frame.

12. The tire testing apparatus of claim 1, wherein the aforementioned axle portion comprises: a main shaft; a third bearing rotatably supporting the aforementioned main shaft; and a hub coaxially mounted on the front end of the aforementioned main shaft and on which the aforementioned test wheel is mounted.

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