Tire testing device

Abstract

To provide a tire testing device which can detect the distribution of a force applied on the tread of a tire.SOLUTION: According to an embodiment, there is provided a tire testing device including: a road surface part (60) with a road surface (63a); and a carriage (20) for rotatably holding a test wheel (W) with a test tire (T), and travelling along the road surface, with the test wheel being grounded on the road surface; and a load detection unit (65) for detecting a distribution of a load applied on the wheel tread of the test wheel, on the upper surface of the road surface part.SELECTED DRAWING: Figure 17

Description

[Technical field]

[0001] The present invention relates to a tire testing apparatus. [Background technology]

[0002] Since tire performance is affected by road surface conditions, tire evaluation is required for various road surface conditions.

[0003] Tests to evaluate tire performance include road tests in which a test tire is mounted on the wheel rim of a dedicated test vehicle and driven on an actual road surface, and indoor tests in which a test device is installed indoors.

[0004] JP 2015-72215 A (Patent Document 1) describes an example of a testing device used for indoor tire testing. The testing device described in Patent Document 1 includes a rotating drum with a simulated road surface on its outer circumferential surface, and performs testing by rotating the test tire and the drum with the test tire in contact with the simulated road surface. Summary of the Invention [Problem to be solved by the invention]

[0005] Indoor testing has higher test accuracy and is more efficient than road testing, but conventional indoor testing equipment runs the vehicle over a simulated road surface at high speed during testing, making it difficult to conduct testing on road surfaces covered with rain, snow, gravel, etc.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a tire testing apparatus capable of performing indoor testing under various road surface conditions. [Means for solving the problem]

[0007] According to one embodiment of the present invention, there is provided a tire testing apparatus comprising a road surface portion having a road surface, and a carriage that rotatably holds a test wheel equipped with a test tire and can run along the road surface with the test wheel in contact with the road surface.

[0008] According to one aspect of an embodiment of the present invention, there is provided a tire testing apparatus comprising: a road surface portion having a road surface; a carriage that rotatably holds a test wheel equipped with a test tire and can run along the road surface with the test wheel in contact with the road surface, wherein at least a portion of the road surface portion is constituted by a replaceable road surface unit.

[0009] According to another aspect of an embodiment of the present invention, there is provided a tire testing apparatus comprising: a carriage that rotatably holds a test wheel equipped with a test tire and that can run along a road surface with the test wheel in contact with the road surface; and a drive system that drives the test wheel and the carriage, wherein the drive system comprises carriage drive means that drives the carriage at a predetermined speed relative to the road surface, test wheel drive means that drives the test wheel at a rotation speed corresponding to the predetermined speed, drive means that generates power used to drive the carriage and the test wheel, and power distribution means that distributes the power generated by the drive means to the carriage drive means and the test wheel drive means.

[0010] According to yet another aspect of an embodiment of the present invention, there is provided a tire testing apparatus comprising: a carriage that rotatably holds a test wheel having a test tire and that can run along a road surface with the test wheel in contact with the road surface; and a drive system that drives the test wheel and the carriage, wherein the drive system comprises a drive means that generates power used to drive the carriage and the test wheel, and a first wrapping transmission mechanism that transmits the power generated by the drive means, and the first wrapping transmission mechanism comprises a drive pulley connected to the output shaft of the drive means, a driven pulley held by the carriage and connected to the test wheel, and a first wrapping medium node that is stretched across the drive pulley and the driven pulley, and the first wrapping medium node has a first part and a second part that are stretched in the traveling direction of the carriage and driven in opposite directions to each other, the first part passes through the driven pulley, and the second part is fixed to the carriage.

[0011] According to yet another aspect of an embodiment of the present invention, there is provided a tire testing apparatus comprising: a carriage that rotatably holds a test wheel equipped with a test tire and that can run on a base along a road surface with the test wheel in contact with the road surface; and a drive system that drives the test wheel and the carriage, wherein the drive system comprises test wheel drive means that drives the test wheel, the test wheel drive means comprising rotational motion supply means that supplies rotational motion with a rotational speed corresponding to the speed of the carriage, and torque applying means that changes the phase of the rotational motion supplied from the rotational motion supply means to apply a predetermined torque to the test wheel.

[0012] According to yet another aspect of an embodiment of the present invention, there is provided a tire testing apparatus comprising: a carriage that rotatably holds a test wheel having a test tire and that can run on a base along a road surface with the test wheel in contact with the road surface; and a drive system that drives the test wheel and the carriage, wherein the drive system comprises a test wheel drive means that drives the test wheel, the test wheel drive means comprising two drive means that generate power to drive and rotate the test wheel, and a power combining means that combines the power generated by the two drive means, and the two drive means include a first motor mounted on the base and a second motor mounted on the carriage. Effect of the Invention

[0013] According to an embodiment of the present invention, it becomes possible to carry out indoor testing of various road surface conditions. [Brief description of the drawings]

[0014] [Figure 1] 1 is a front view of a tire testing device according to an embodiment of the present invention. [Diagram 2] 1 is a left side view of a tire testing device according to an embodiment of the present invention. [Diagram 3] 1 is a plan view of a tire testing device according to an embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing a carriage and its surrounding structure. [Diagram 5] FIG. 2 is a diagram showing a carriage and its surrounding structure. [Figure 6] FIG. 2 is a diagram showing a carriage and its surrounding structure. [Figure 7] FIG. [Figure 8] FIG. 2 is a side cross-sectional view of a torque generating device. [Figure 9] FIG. 2 is a diagram showing the structure of a spindle and its surroundings. [Figure 10] FIG. 2 is a block diagram showing a schematic configuration of a control system. [Figure 11] FIG. [Figure 12] A cross-sectional view of a first modified example of the road surface portion. [Figure 13] A cross-sectional view of a second modified example of the road surface portion. [Figure 14] FIG. 11 is a cross-sectional view of the road surface portion near the load detection portion in the second modified example. [Figure 15] FIG. 11 is a plan view of the vicinity of a load detection portion of a road surface portion in a second modified example. [Figure 16] FIG. 13 is a plan view of the vicinity of a load detection portion of a road surface portion in a third modified example. [Figure 17] FIG. 13 is a side view of the vicinity of the load detection portion of the road surface portion in the third modified example. [Figure 18] FIG. 13 is a front view of a load detection section in a third modified example. [Figure 19] FIG. 13 is a side view of a load detection section in a third modified example. [Figure 20] FIG. 13 is a plan view of a load detection section in a third modified example. [Figure 21] FIG. 13 is a plan view showing a state in which a movable part of a load detector in a third modified example is removed. [Figure 22] FIG. 19 is an enlarged view of region E in FIG. [Figure 23] 10 is a flowchart showing a procedure for acquiring the distribution of loads applied to a tire tread in a third modified example. [Figure 24] 13 is a flowchart showing a procedure for load profile calculation in a third modified example. [Diagram 25]FIG. 13 is a plan view showing the arrangement relationship between the load detection module and the rotation shaft of the test wheel in the third modified example. [Figure 26] 13 is a display example of a load profile in the third modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same or corresponding items are denoted by the same or corresponding reference numerals, and duplicated description will be omitted.

[0016] Figures 1 to 3 are respectively a front view, a left side view, and a plan view of a tire testing device 1 according to one embodiment of the present invention. Figures 4 to 6 are respectively a front view, a left side view, and a plan view showing a carriage 20 and its surrounding structure, which will be described later. Note that in Figures 4 to 6, for the sake of convenience of explanation, some of the configuration is omitted or shown in cross section.

[0017] 2 and 5, the direction from right to left is defined as the X-axis direction, the direction perpendicular to the paper from back to front is defined as the Y-axis direction, and the direction from bottom to top is defined as the Z-axis direction. The X-axis and Y-axis directions are horizontal directions that are perpendicular to each other, and the Z-axis direction is vertical. Additionally, the front-back, up-down, and left-right directions are defined as directions when facing the carriage travel direction (X-axis positive direction). In other words, the X-axis positive direction is the front, the X-axis negative direction is the back, the Y-axis positive direction is the left, the Y-axis negative direction is the right, the Z-axis positive direction is the up, and the Z-axis negative direction is the down.

[0018] The tire testing device 1 includes a track section 10 and a road surface section 60 that are elongated in the X-axis direction, and a carriage 20 that can run on the track section 10 in the X-axis direction. As shown in FIG. 3, a long and narrow space Sp1 is provided on the left part of the track section 10, extending over substantially the entire length of the track section 10 in the X-axis direction. The road surface section 60 is accommodated in this space Sp1. A road surface 63a (pavement section 63) on which a test tire T mounted on the carriage 20 comes into contact is provided on the upper surface of the road surface section 60. In this embodiment, the track section 10 and the road surface section 60 are separated so that the road surface section 60 can be replaced depending on the test conditions. Note that a base frame 11 (hereinafter abbreviated as "base 11") of the track section 10 and a frame 61 of the road surface section 60 may be integrally formed.

[0019] A test wheel W (a wheel rim Wr on which a test tire T is mounted) is attached to the carriage 20. During testing, the carriage 20 runs with the test wheel W in contact with the road surface 63a, and the test tire T rolls on the road surface 63a.

[0020] The track section 10 includes a plurality of (three in this embodiment) linear guideways (hereinafter abbreviated as "linear guides") 13 that guide the movement of the carriage 20 in the X-axis direction, and one or more drive units 14 that generate mechanical power to drive the carriage 20. In this embodiment, two pairs of drive units 14 (a pair of drive units 14LA, 14LB on the left side and a pair of drive units 14RA, 14RB on the right side) are installed near the four corners on the base 11 of the track section 10. The drive units 14LA and 14RA are disposed at the rear end of the track section 10, and the drive units 14LB and 14RB are disposed at the front end of the track section 10.

[0021] 6, each drive unit 14 includes a servo motor 141 and an optional reducer 142 that reduces the rotational speed of the output of the servo motor 141. The right drive units 14RA and 14RB serve both as a carriage drive means for driving the carriage 20 to travel, and as a rotational motion supply means for supplying the test wheel W with a rotational motion having a rotational speed corresponding to the travel speed of the carriage. The left drive units 14LA and 14LB serve as a carriage drive means.

[0022] In this embodiment, the servo motor 141 has a moment of inertia of 0.01 kg m 2 Less than or equal to 0.008 kg m 2 An ultra-low inertia, high-power AC servo motor with a rated output of 3 kW to 60 kW (more practically, 7 kW to 37 kW) is used.

[0023] The tire testing apparatus 1 also includes a pair of belt mechanisms 50 (50L, 50R) on the left and right sides. The belt mechanisms 50 transmit power generated by the drive unit 14 to the carriage 20 to drive the carriage 20 in the X-axis direction. Each belt mechanism 50 includes a toothed belt 51, a pair of drive pulleys 52 (52A, 52B), and three driven pulleys 53 (53A, 53B, 53C). The drive pulley 52 and the driven pulley 53 are all toothed pulleys that mesh with the toothed belt 51.

[0024] The toothed belt 51 has a core wire of steel wire. The toothed belt 51 may have a core wire made of so-called super fibers such as carbon fibers, aramid fibers, and ultra-high molecular weight polyethylene fibers. By using a lightweight and high-strength core wire such as a carbon core wire, it becomes possible to drive the carriage 20 at high acceleration (or apply high driving force / braking force to the test wheels W) using a motor with a relatively low output, and the tire testing apparatus 1 can be made smaller (or have a larger capacity).

[0025] The right belt mechanism 50R serves as a carriage drive means for driving the carriage 20 to run, and also serves as a primary power transmission unit for transmitting the power supplied from the rotational power supply means (drive units 14RA and 14RB) to a secondary power transmission unit to be described later. The left belt mechanism 50L serves as a carriage drive means.

[0026] In the following description, in the case of a pair of configurations provided on the left and right sides, the configuration on the left side will be described as a general rule, and the configuration on the right side will be described in brackets as well, and duplicate descriptions will be omitted.

[0027] The toothed belt 51 of the left [right] belt mechanism 50L [50R] is wound around a pair of drive pulleys 52 (52A, 52B) and three driven pulleys 53 (53A, 53B, 53C). The pair of drive pulleys 52A, 52B are respectively coupled to the output shafts of a pair of drive units 14LA, 14LB [14RA, 14RB] on the left [right] side. The three driven pulleys 53A, 53B, 53C are attached to the left [right] side driven unit 22L [22R] described later.

[0028] 5, both ends of each toothed belt 51 are fixed to the main frame 21 of the carriage 20 by belt clamps 54 (54A, 54B), and each toothed belt 51 forms a loop through the carriage 20. A pair of drive pulleys 52A, 52B (FIG. 2) of the belt mechanism 50 are disposed with an area in which the carriage 20 can run sandwiched therebetween, and are held on the base 11 (i.e., are fixed pulleys whose center of gravity is fixed relative to the base 11). The driven pulley 53 (FIG. 5) is a movable pulley that is held by the carriage and can move together with the carriage.

[0029] In this embodiment, the pair of drive units 14LA, 14LB [14RA, 14RB] are driven in the same phase. The drive pulley 52 and the driven pulley 53 have the same effective diameter (i.e., pitch circle diameter) or the same number of teeth. The left drive units 14LA, 14LB and the right drive units 14RA, 14RB are installed in opposite directions and are driven in opposite phases. When the toothed belt 51L [51R] is driven by the drive units 14LA and 14LB [14RA and 14RB], the carriage 20 is pulled by the toothed belt 51L [51R] and driven in the X-axis direction.

[0030] The track section 10 includes a plurality of (three in this embodiment) linear guides 13 (13A, 13B, 13C). Each linear guide 13 includes one rail 131 that forms a track extending in the X-axis direction, and one or more (three in this embodiment) carriages (hereinafter referred to as "runners 132") that can run on the rail 131. Each rail 131 is laid on the upper surface of the base 11 of the track section 10. The rails 131 of the two linear guides 13A and 13B are arranged along both the left and right ends of the space Sp1 (i.e.), and the rail 131 of the remaining linear guide 13C is arranged along the right end of the base 11 and is attached to the base 11, respectively. In addition, each runner 132 is attached to the lower surface of the carriage 20.

[0031] 6, the carriage 20 includes a main frame 21, driven parts 22L and 22R which respectively hold driven pulleys 53 of the belt mechanisms 50L and 50R, a spindle part 28 (FIG. 4) which rotatably holds a test wheel W on which a test tire T is mounted, an alignment part 40 which can adjust the alignment and load of the test wheel W with respect to a road surface 63a, and a spindle drive mechanism 20D which rotationally drives a spindle 280 of the spindle part 28. The spindle 280 is an axle on which the test wheel W is attached.

[0032] 7 is a cross-sectional view showing a schematic structure of the right driven part 22R. The driven part 22R includes a frame 221, three sets of bearings 222, and three shafts 223A-C. The frame 221 has three through holes extending in the Y-axis direction, and the shafts 223A-C are rotatably supported by a set of bearings 222 fitted into each of the through holes. In this embodiment, each of the shafts 223A-C is supported by a pair of bearings 222, but the shafts 223A-C may be supported by one or three or more bearings 222. The driven pulleys 53A-C of the belt mechanism 50R are attached to one end of the shafts 223A-C protruding from one surface of the frame 221, respectively.

[0033] In the right-side driven part 22R, only the central shaft 223B in the X-axis direction is longer than the other two shafts (223A, 223C), and the other end of the shaft 223B protrudes from the other surface of the frame 221. A drive pulley 231 of the belt mechanism 23, which will be described later, is attached to the other end of the shaft 223B. That is, the right-side belt mechanism 50R and the belt mechanism 23 are connected via the shaft 223B.

[0034] The left-side driven part 22L is configured in the same manner as the right-side driven part 22R described above, but differs from the right-side driven part 22R in that it is arranged in the opposite left-right direction, that the three shafts 223A-C are all short, and that the drive pulley 231 is not attached to the other end of the shaft 223B.

[0035] As shown in Fig. 6, the spindle drive mechanism 20D includes a belt mechanism 23, a torque applying device 30, a belt mechanism 24, and a sliding constant velocity joint 25. Power transmitted from the right belt mechanism 50R to the belt mechanism 23 via the shaft 223B (Fig. 7) of the right driven part 22R is transmitted to the spindle part 28 (Fig. 4) via the torque applying device 30, the belt mechanism 24, and the sliding constant velocity joint 25, and drives and rotates the test wheel W attached to the spindle part 28. In other words, part of the power generated by the right drive parts 14RA, 14RB is used to drive the carriage 20, and another part is used to drive and rotate the test wheel W. In other words, the right-side belt mechanism 50R serves as a means for driving the carriage 20 (carriage driving means), a means for driving the test wheel W (test wheel driving means), and a means for distributing the power generated by the driving units 14RA and 14RB into power used to drive the carriage 20 and power used to drive the test wheel W (power distribution means).

[0036] The toothed belt 51 of the belt mechanism 50 has an upper part 51a and a lower part 51b stretched in the running direction of the carriage 20 and driven in opposite directions. Specifically, the lower part 51b of the toothed belt 51 fixed to the carriage 20 is driven together with the carriage 20 in the running direction of the carriage, and the upper part 51a is driven in the opposite direction to the carriage 20 and the lower part 51b. The driven pulley 53 attached to the carriage 20 is wrapped around the upper part 51a of the toothed belt 51 running in the opposite direction to the carriage 20, and is driven by the upper part 51a. The power given to the driven pulley 53B is transmitted to the test wheel W by a secondary power transmission unit composed of the belt mechanism 23, the torque applying device 30, the belt mechanism 24, the sliding constant velocity joint, and the spindle unit 28, and is used to drive the test wheel W. Such a configuration of the belt mechanism 50 enables both the carriage 20 and the test wheel W to be driven by the toothed belt 51.

[0037] In this embodiment, a configuration is adopted in which the carriage 20 and the test wheel W are driven using rotational motion transmitted by a common power transmission device (i.e., the belt mechanism 50R). This configuration makes it possible to always rotate the test wheel W at a peripheral speed (number of rotations) corresponding to the running speed of the carriage 20, regardless of the running speed of the carriage 20. Furthermore, in this embodiment, in order to reduce the amount of operation of the torque applying device 30 (i.e., power consumption), the test wheel W is configured to rotate at approximately the same peripheral speed as the running speed of the carriage 20 when the torque applying device 30 is not operating.

[0038] 8 is a side cross-sectional view of the torque applying device 30. The torque applying device 30 generates a torque to be applied to the test wheel W, and outputs the torque by superimposing it on the rotational motion transmitted by the belt mechanism 23. In other words, the torque applying device 30 can apply a torque to the test wheel W (i.e., apply a driving force or a 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 23.

[0039] By incorporating the torque applying device 30 into the spindle drive mechanism 20D, it becomes possible to share the roles of the power source for controlling the rotation speed (drive units 14RA, 14RB) and the power source for controlling the torque (servo motor 32 described later). This makes it possible to use a power source with a smaller capacity and to control the rotation speed and torque applied to the test wheel W with higher accuracy. Furthermore, by incorporating the torque applying device 30 into the carriage 20, the torque applied to the belt mechanism 50L is reduced, making it possible to make the belt mechanism 50L smaller (for example, by reducing the number of toothed belts used) and to use members with a lower load capacity.

[0040] The torque applying device 30 includes a housing 31, a servo motor 32, a reducer 33, and a shaft 34 installed in the housing 31, two bearings 35 and 36 that rotatably support the housing 31, a slip ring unit 37, a support 38 that supports the slip ring unit 37, and a rotary encoder 39. The number of rotations of the housing 31 is detected by the rotary encoder 39.

[0041] In this embodiment, the servo motor 32 has a moment of inertia of 0.01 kg m 2 Below, ultra-low inertia, high-output AC servo motors with rated output of 7kW to 37kW are used.

[0042] The housing 31 has a motor accommodating portion 311 and a cap portion 312 that are substantially cylindrical and have a large diameter, and a pair of substantially cylindrical shaft portions 313 and 314 that are smaller in diameter than the motor accommodating portion 311. The shaft portion 313 is coaxially coupled (i.e., so as to share a center line) to one end (the left end in FIG. 8) of the motor accommodating portion 311. The shaft portion 314 is coaxially coupled to the other end (the right end in FIG. 8) of the motor accommodating portion 311 via the cap portion 312. The shaft portion 313 is rotatably supported by a bearing portion 36, and the shaft portion 314 is rotatably supported by a bearing portion 35.

[0043] A flange 314a is formed at the tip of the shaft portion 314, and a driven pulley 232 of the belt mechanism 23 is coaxially coupled to this flange 314a. In addition, a toothed belt 233 of the belt mechanism 23 is wound around the driven pulley 232 and a driving pulley 231 (FIG. 7). The housing 31 is rotationally driven by the belt mechanism 23.

[0044] A bearing 315 is provided on the inner periphery of the shaft portion 314. The shaft 34 is passed through the hollow portion of the shaft portion 314 and rotatably supported by the bearing 315. The shaft 34 passes through the shaft portion 314 and the driven pulley 232, and one end of the shaft 34 protrudes into the cap portion 312. The other end of the shaft 34 passes through the hole 232a of the driven pulley 232 and is coaxially coupled to the driving pulley 241 of the belt mechanism 24. A toothed belt 243 is wound around the driving pulley 241.

[0045] A servo motor 32 is housed in the hollow portion of the motor housing portion 311. The servo motor 32 has a shaft 321 arranged coaxially with the motor housing portion 311, and a motor case 320 (i.e., a stator) fixed to the motor housing portion 311 by a plurality of stud bolts 323. A flange 322 of the servo motor 32 is connected to a gear case 331 of the reducer 33 via a connecting tube 324. In addition, the gear case 331 of the reducer 33 is fixed to an inner flange 312a of the cap portion 312.

[0046] The shaft 321 of the servo motor 32 is connected to an input shaft 332 of the reducer 33. In addition, a shaft 34 is connected to an output shaft 333 of the reducer 33. The torque output from the servo 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 24 is obtained by superimposing the torque generated by the servo motor 32 and the reducer 33 on the rotation of the housing 31 driven by the belt mechanism 23. That is, the shaft portion 314 of the housing 31 is the input shaft of the torque applying device 30, and the shaft 34 is the output shaft of the torque applying device 30. The torque applying device 30 superimposes the torque generated by the torque applying device 30 on the rotational motion transmitted to the input shaft and outputs the superimposed torque from the output shaft.

[0047] The slip ring unit 37 includes a plurality of pairs of slip rings 37a, brushes 37b, a support frame 37c, and a connecting pipe 37d. The plurality of slip rings 37a are spaced apart from each other and fitted around the outer periphery of the connecting pipe 37d.

[0048] The connecting pipe 37d is coaxially coupled to the shaft portion 313 of the housing 31. The brushes 37b, which come into contact with the outer circumferential surface of the corresponding slip ring 37a, are supported by a support frame 37c attached to a support 38. The cable 325 of the servo motor 32 is passed through the hollow portion of the shaft portion 313 and connected to the slip ring 37a. The brushes 37b are connected to the servo amplifier 32a (FIG. 10). That is, the servo motor 32 and the servo amplifier 32a are connected via the slip ring portion 37.

[0049] 4 and 6, the driven pulley 242 around which the toothed belt 243 of the belt mechanism 24 is wound is coaxially coupled to one end of a shaft 261 rotatably supported by a bearing portion 262. The other end of the shaft 261 is connected to one end of the sliding type constant velocity joint 25. The other end of the sliding type constant velocity joint 25 is coupled to a spindle 280 via a shaft 263 or the like. The sliding type constant velocity joint 25 is configured to be able to transmit rotation smoothly without rotation fluctuation, regardless of the operating angle (the angle between the input shaft and the output shaft). The length of the sliding type constant velocity joint 25 is also variable.

[0050] Spindle 280 is supported by alignment unit 40 so that its angle and input shaft position are variable. By connecting spindle 280 and shaft 261 held by bearing unit 262 via sliding constant velocity joint 25, even if the angle or position of spindle 280 changes, sliding constant velocity joint 25 flexibly follows this change. Therefore, no significant strain is applied to spindle 280 or shafts 261 and 263, and rotation is transmitted smoothly to spindle 280 without changing the speed.

[0051] As shown in FIG. 5, the alignment section 40 includes a pair of swivel frames 41, a pair of curved guideways 42 (hereinafter abbreviated as “curved guides”), a slide frame 44, and two pairs of linear guides 43.

[0052] Each of the swivel frames 41 is placed on the main frame 21 of the carriage 20 via a curved guide 42. The curved guide 42 includes an arc-shaped rail 421 attached to the upper surface of the main frame 21, and a plurality of carriages 422 (hereinafter referred to as "runners 422") (two in this embodiment) that can run on the rail 421. The runners 422 are attached to the bottom surface of the swivel frame 41. The pair of curved guides 42 and the pair of swivel frames 41 are disposed facing each other in the front and rear, sandwiching a vertical line V that passes through the center C of the test wheel W. The center of curvature of each of the curved guides 42 is on the vertical line V. That is, each of the swivel frames 41 is supported by the curved guide 42 so as to be rotatable about the vertical line V.

[0053] 4, the slide frame 44 has, in order from the top, a pillar portion 441, a connecting portion 442, and a fork 443. The pillar portion 441 (i.e., the upper portion of the slide frame 44) is vertically disposed so that its center line coincides with the vertical line V. The fork 443 (i.e., the lower portion of the slide frame 44) is recessed to the right (in the direction of the rotation axis Ay) from the vertical line V so as not to come into contact with the test wheel W. The connecting portion 442 extends in the Y-axis direction and connects the lower end of the pillar portion 441 and the upper end of the fork 443. Therefore, the slide frame 44 is formed in a substantially crank shape when viewed from the X-axis direction.

[0054] 5, the lower portion of fork 443 is branched into a front portion and a rear portion. Bearings 443a are provided coaxially on the two branched lower ends of fork 443.

[0055] 9 is a diagram showing the spindle portion 28 and its surrounding structure. The spindle portion 28 is disposed between a pair of bearings 443a (FIG. 5) provided at the lower end of the fork 443, with the central axis (rotation axis Ay) of the spindle 280 facing left and right. The spindle portion 28 is supported by the pair of bearings 443a so as to be rotatable about a rotation axis Cx extending forward and backward. Note that the directions of the rotation axis Ay of the spindle 280 and the rotation axis Cx of the spindle case 284 change depending on the alignment of the spindle 280, and do not necessarily coincide with the Y-axis direction or the X-axis direction.

[0056] The spindle section 28 includes a spindle 280 and a spindle case 284 that rotatably supports the spindle 280. The spindle 280 includes a body 281, a six-component force sensor 282, and a hub 283. The body 281 is a cylindrical shaft. The six-component force sensor 282 is a substantially cylindrical member that is coaxially attached to the tip of the body 281, and is a piezoelectric force sensor that can detect six-component forces (forces in three orthogonal axial directions and torques around each axis). The hub 283 is a member for attaching the test wheel W, and is coaxially attached to the tip of the six-component force sensor 282. The body 281, the six-component force sensor 282, and the hub 283 are integrally joined to form the spindle 280. The spindle 280 is an axle to which the test wheel W is attached and which rotates integrally with the test wheel. The test wheel W is attached integrally to the six-component force sensor 282 via a hub 283, so that the six-component force sensor 282 detects the six-component force acting on the test wheel W.

[0057] The spindle case 284 is a substantially cylindrical member that houses and rotatably holds the spindle 280. A bearing 285 and a pair of bearings 286 are attached to the inner periphery of the spindle case 284. The spindle 280 is rotatably supported by the bearings 285 and 286.

[0058] A pair of pivot shafts 287 rotatably fitted into a pair of bearings 443a (FIG. 5) of the fork 443 are attached to the front and rear side surfaces of the spindle case 284. That is, the spindle portion 28 is supported by the pair of bearings 443a to be rotatable about the rotation axis Cx.

[0059] As shown in Fig. 4, the alignment section 40 includes a load adjustment section 45, a slip angle adjustment section 46, and a camber adjustment section 47. The load adjustment section 45 is a unit that adjusts the load applied to the test wheel W. The slip angle adjustment section 46 is a unit that adjusts the slip angle of the test wheel W by rotating the alignment section 40 (directly, the rotating frame 41) about the vertical line V. The camber adjustment section 47 is a unit that adjusts the camber angle of the test wheel W by rotating the spindle section 28 about the rotation axis Cx (Fig. 9).

[0060] The load adjustment unit 45 includes a servo motor 451, a motion converter 452, and a bracket 453. The above-mentioned linear guide 43 can also be included in the load adjustment unit 45. The servo motor 451 is attached to the main frame 21 of the carriage 20. The motion converter 452 is a device that converts the rotational motion of the servo motor 451 into the vertical linear motion of a mover 452a that is vertically erected. For example, a rack and pinion mechanism, a mechanism that combines a cross shaft such as a bevel gear with a feed screw, or a mechanism that combines a misaligned shaft such as a worm gear or a screw gear with a feed screw, is used for the motion converter 452. The bracket 453 is disposed directly below the mover 452a of the motion converter 452, and is attached to the side of the column part 441 of the slide frame 44 with the seat surface 453a facing upward.

[0061] When the servo motor 451 is driven to lower the mover 452a of the motion converter 452, the lower end of the mover 452a comes into contact with the seat surface 453a of the bracket 453. When the servo motor 451 is further driven, the mover 452a presses the slide frame 44 vertically downward via the bracket 453. As a result, the test wheel W held by the alignment unit 40 is pressed against the road surface 63a, and a load according to the height of the mover 452a (i.e., the position in the Z-axis direction) is applied between the test tire T and the road surface 63a. The load applied to the test wheel W is detected by the six-component force sensor 282 (FIG. 8) of the spindle unit 28. Then, the drive of the servo motor 451 is controlled so that the detected load matches the set load value.

[0062] 6, a portion of the load adjustment section 45 is disposed in a space Sp2 surrounded by the pair of revolving frames 41 and the pillar section 441 of the slide frame 44. This configuration makes effective use of the space and achieves a compact carriage.

[0063] The slip angle adjustment unit 46 includes a servo motor 461 attached to the main frame 21 of the carriage 20, a reducer 462, a drive gear 463 coupled to the output shaft of the reducer 462, and a driven gear 464 meshing with the drive gear 463. For example, a spur gear or a sector gear is used for the drive gear 463. The driven gear 464 is a sector gear. Note that a worm gear, a bevel gear, a screw gear, or the like may be used for the gear mechanism (drive gear 463, driven gear 464) of the slip angle adjustment unit 46. The servo motor 461, the reducer 462, and the drive gear 463 are attached to the main frame 21 of the carriage 20. The driven gear 464 is attached to a side surface of the pillar portion 441 of the slide frame 44 so that its rotation axis coincides with the vertical line V.

[0064] The rotation of the servo motor 461 is decelerated by the reducer 462 and transmitted to the driven gear 464 via the drive gear 463. Then, the driven gear 464 and the slide frame 44 rotate about the vertical line V. As a result, the test wheel W supported by the slide frame 44 via the spindle portion 28 also rotates about the vertical line V, and the slip angle of the test wheel W changes.

[0065] As shown in Fig. 6, a part of the slip angle adjustment unit 46 is disposed in a space Sp3 surrounded by the pair of revolving frames 41 and the pillar portion 441 of the slide frame 44. This configuration makes effective use of the space and realizes a compact carriage. Note that the space Sp2 in which the load adjustment unit 45 is disposed and the space Sp3 in which the slip angle adjustment unit 46 is disposed are spaces provided on the left and right opposite sides of the pillar portion 441. By disposing the load adjustment unit 45 and the slip angle adjustment unit 46 in different spaces, the efficiency of assembly and maintenance is improved.

[0066] 9, the camber adjustment portion 47 includes an upper arm 471 attached to the right end of the connecting portion 442, a joint 472 rotatably supported by the upper arm 471, a fully threaded bolt 475 (hereinafter referred to as "stud 475") to which the joint 472 is attached, a rod end 476 attached to one end of the stud 475, and a lower arm 478 rotatably connected to the rod end 476 by a pin 477. The lower arm 478 has an end portion fixed to the spindle case 284. The upper arm 471 may be attached to the fork 443 of the slide frame 44.

[0067] The upper arm 471 is a flat plate extending parallel to the rotation axis Ay (i.e., in a direction away from the vertical line V) and is disposed perpendicular to the rotation axis Cx of the spindle case 284. A pivot shaft 471a parallel to the rotation axis Cx is provided at the tip of the upper arm 471.

[0068] The joint 472 is a substantially rectangular parallelepiped member having a through hole formed therein, into which the stud 475 is inserted. The joint 472 is provided with a bearing 473 that rotatably engages with the pivot 471a of the upper arm 471. That is, the joint 472 is supported rotatably about the pivot 471a that is parallel to the rotation axis Cx of the spindle case 284. The joint 472 is fixed to the stud 475 by being sandwiched between a pair of nuts 474 that are fitted onto the stud 475.

[0069] The tip end of the lower arm 478 is connected to the lower end of the rod end 476 by a pin 477. The pin 477 connecting the rod end 476 and the lower arm 478 is also a pivot axis parallel to the rotation axis Cx of the spindle case 284. That is, the slide frame 44 and the upper arm 471 (first link), the stud 475 and the rod end 476 (second link), and the lower arm 478 and the spindle case 284 (third link) are connected in an annular shape via three pivot axes [pivot axis 471a (first joint), pin 477 (second joint), and pivot axis 287 (third joint)] parallel to the rotation axis Cx so as to be rotatable about each pivot axis, thereby constituting a link mechanism.

[0070] By changing the position of the nut 474 on the stud 475, the length of the variable length link 47L connecting the two joints (the pivot 471a and the pin 477) changes. At this time, the lower arm 478 and the spindle case 284 rotate about the pivot 287 (rotation axis Cx), changing the inclination of the spindle 280 and the rotation axis Ay of the test wheel W with respect to the road surface 63a. Therefore, the camber can be adjusted by changing the position of the nut 474 on the stud 475 to expand or contract the variable length link 47L. Expanding the variable length link 47L changes the camber to the negative side, and contracting the variable length link 47L changes the camber to the positive side.

[0071] The tire testing apparatus 1 is equipped with a brake system 27 (hereinafter abbreviated as "brake 27") capable of decelerating the rotation of a spindle 280. The brake 27 is equipped with a disc rotor 271 attached to the spindle 280, a caliper 272 attached to a lower arm 478, and a hydraulic pressure supply device 276 (FIG. 10) that supplies hydraulic pressure to the caliper 272.

[0072] The spindle 280 is connected to the sliding constant velocity joint 25 of the spindle drive mechanism 20D (FIG. 6) via an attachment 273, a disc rotor 271, and a shaft 263.

[0073] The lower arm 478 is formed in a crank shape with its middle part retreated upward (i.e., in the direction away from the spindle 280). The caliper 272 of the brake 27 is attached via an attachment 275 to the middle part of the lower arm 478 away from the spindle 280.

[0074] The attachment 273 and the shaft 263 are replaceable small members manufactured to match the shape of the disc rotor 271. Moreover, the attachment 275 is a relatively easy-to-replace and inexpensive small part manufactured to match the shape of the caliper 272. By using the attachments 273, 275 and the shaft 263, it becomes possible to change the type of the brake 27 at a lower cost because it is not necessary to replace the spindle 280 or the sliding constant velocity joint 25, which are relatively expensive to replace, when changing the type of the brake 27 (disc rotor 271, caliper 272).

[0075] 10 is a block diagram showing a schematic configuration of a control system 1a of the tire testing apparatus 1. The control system 1a includes a control unit 72 that controls the operation of the entire apparatus, a measurement unit 74 that performs various measurements, and an interface unit 76 that performs input and output with the outside.

[0076] The control unit 72 is connected to the servo motors 141 of the drive units 14, the servo motor 32 of the torque applying device 30, the servo motor 451 of the load adjustment unit 45, and the servo motor 461 of the slip angle adjustment unit 46 via servo amplifiers 141a, 32a, 451a, and 461a, respectively.

[0077] In addition, a hydraulic pressure supply device 276 of the brake 27 is connected to the control unit 72. The hydraulic pressure supply device 276 generates a predetermined hydraulic pressure based on a command from the control unit 72 and supplies the hydraulic pressure to the caliper 272. The hydraulic pressure supply device 276 includes a servo motor 276b, a motion converter 276c that converts the rotational motion output by the servo motor 276b into linear motion, a brake master cylinder 276d that is driven by the linear motion output by the motion converter 276c, and a servo amplifier 276a that generates a drive current to be supplied to the servo motor 276b based on a command from the control unit 72.

[0078] The control unit 72 and each of the servo amplifiers 141a, 276a, 32a, 451a, and 461a are communicatively connected by optical fibers, enabling high-speed feedback control between the control unit 72 and each of the servo amplifiers. This enables synchronous control with higher precision (high resolution and high accuracy on the time axis).

[0079] A six-component force sensor 282 is connected to the measurement unit 74 via a preamplifier 282a. A signal from the six-component force sensor 282 is amplified by the preamplifier 282a and then converted into a digital signal in the measurement unit 74 to generate measurement data. The measurement data is input to the control unit 72. In addition, phase information detected by rotary encoders RE built into the servo motors 141, 276b, 32, 451, and 461 is input to the control unit 72 via the servo amplifiers 141a, 276a, 32a, 451a, and 461a, respectively.

[0080] The interface unit 76 includes, for example, one or more of a user interface for inputting and outputting data with a user, a network interface for connecting to various networks such as a LAN (Local Area Network), and various communication interfaces such as a Universal Serial Bus (USB) and a General Purpose Interface Bus (GPIB) for connecting to external devices. The user interface also includes, for example, one or more of various input / output devices such as various operation switches, a display, various display devices such as an LCD (Liquid Crystal Display), various pointing devices such as a mouse and a touch pad, a touch screen, a video camera, a printer, a scanner, a buzzer, a speaker, a microphone, a memory card reader / writer, and the like.

[0081] The control unit 72 can make the carriage 20 travel at a predetermined speed by synchronously controlling the driving of the servo motors 141 of the drive units 14 based on the speed data input via the interface unit 76. In this embodiment, all four drive units 14 are driven in the same phase (strictly speaking, the drive units 14LA, 14LB on the left side and the drive units 14RA, 14RB on the right side are driven in opposite phases [reverse rotation]).

[0082] The control unit 72 can also apply a predetermined longitudinal force to the test tire T by controlling the drive of the servo motor 32 of the torque applying device 30 based on data of the longitudinal force (braking force or driving force) to be applied to the test tire T acquired via the interface unit 76. The control unit 72 can also apply a predetermined torque to the test wheel W by controlling the torque applying device 30 based on torque data (or acceleration data) instead of the longitudinal force data.

[0083] The control unit 72 can synchronize the control of the drive unit 14, which causes the carriage 20 to run at a predetermined running speed (and at the same time rotates the test tire T at a peripheral speed approximately the same as the running speed), and the control of the torque imparting device 30, which applies longitudinal force (or torque) to the test tire T, based on a synchronization signal.

[0084] The torque waveform generated by the torque applying device 30 may be a basic waveform such as a sine wave, a half sine wave, a sawtooth wave, a triangular wave, a trapezoidal wave, etc., or a longitudinal force (or torque) waveform measured in a road test, a longitudinal force (or torque) waveform obtained by a simulation calculation, or any other composite waveform (for example, a waveform generated by a function generator, etc.).

[0085] Similarly, for controlling the running speed of the carriage 20 (or the rotation speed of the test wheel W), in addition to the basic waveform, a waveform of the wheel rotation speed measured in a road test, a waveform of speed change obtained by simulation calculation, or any other composite waveform (for example, a waveform generated by a function generator, etc.) can be used.

[0086] 11 is a cross-sectional view of the road surface portion 60. The road surface portion 60 comprises a frame 61 and a main body portion 60a supported by the frame 61. The main body portion 60a comprises a base 62 and a pavement portion 63 held on the base 62. A recess 621 is formed on the upper surface of the base 62, extending in the extension direction of the road surface portion 60 (i.e., the X-axis direction which is the running direction of the carriage 20). The pavement portion 63 is formed, for example, by filling the recess 621 with a simulated pavement material described later and allowing it to harden. A road surface 63a on which the test wheel W comes into contact is formed on the upper surface of the pavement portion 63.

[0087] In this embodiment, the main body 60a is composed of a main body unit 600a, which is a road surface unit (a replaceable structure including at least a part of the road surface 63a), and is detachably attached to the frame 61. The road surface unit is not limited to the form in which the main body 60a is unitized as in this embodiment (referred to as the "main body unit"), but can also be a form in which only the pavement portion 63 is unitized (referred to as the "pavement portion unit") or a form in which the entire road surface portion 60 including the frame 61 is unitized (referred to as the "road surface portion unit").

[0088] The main body 60a of this embodiment is composed of a plurality of main body units 600a obtained by dividing the main body 60a in the extension direction, and each main body unit 600a can be replaced. The entire main body 60a may be formed as a single replaceable road surface unit.

[0089] As in this embodiment, by configuring the road surface portion 60 from road surface units such as the main body unit 600a, it becomes possible to replace at least a part of the road surface 63a by replacing the road surface unit.

[0090] For example, it is possible to change the type (e.g., material, structure, surface shape, etc.) of the pavement section 63 only in the center portion by replacing only the main body unit 600a in the extension direction (X-axis direction) of the road surface section 60. Also, the type of the pavement section 63 may be changed for each main body unit 600a so that, for example, the friction coefficient in the extension direction of the road surface section 60 varies.

[0091] A recess 622 that fits into a protrusion 612 provided on the upper surface of the frame 61 is provided on the lower surface of the base 62. The main body unit 600a is placed on the frame 61 so that the protrusion 612 fits into the recess 622, and the two are fixed together by a fixing means (not shown) such as a bolt or a cam lever, whereby the main body unit 600a is detachably attached to the frame 61.

[0092] In this embodiment, the frame 61 is also formed of a plurality of frame units 610 obtained by dividing the frame 61 in the extension direction, and each frame unit 610 can be replaced.

[0093] In this embodiment, the frame unit 610 and the main body unit 600a are formed to have the same length, and the road surface unit 600, which is the frame unit 610 to which the main body unit 600a is attached, can be replaced as a unit.

[0094] In addition, in this embodiment, the paving section 63 is formed integrally with the base 62, but the paving section 63 may be configured to be detachable from the base 62. For example, the paving section 63 may be configured from a plurality of paving section units 630 obtained by dividing the paving section 63 in the extension direction, and the paving section 63 may be configured to be replaceable in units of the paving section units 630. In this case, the paving section units 630 and the base unit 620 may be formed to have the same length, and the combined unit in which the paving section unit 630 is attached to the base unit 620 (in other words, the main body unit 600a in which the paving section 63 is detachable) may be replaceable. Also, the frame unit 610, the base unit 620, and the paving section unit 630 are assembled to produce the road surface unit 600, and the road surface unit 600 may be replaceable in units of the road surface unit 600.

[0095] As described above, in this embodiment, a plurality of road surface unit 600 are connected to form the road surface portion 60. With this configuration, it is possible to extend or shorten the road surface portion 60 by adding or removing road surface unit 600. Also, by making the plurality of road surface units have the same structure, it becomes possible to efficiently manufacture the road surface portion 60.

[0096] In this embodiment, like the road surface section 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 extended or shortened by adding or deleting the track section units 100. The track section units 100 are formed to have the same length as the road surface section units 600. Therefore, the lengths of the track section 10 and the road surface section 60 can be made the same. Also, the track section 60 and the track section 10 may be configured to be extended, shortened or partially replaced in units of a composite unit in which the track section units 100 and the road surface section units 600 are integrated.

[0097] In the road surface portion 60 of this embodiment, a simulated pavement that simulates an asphalt-paved road (i.e., the impact on the tire, such as the amount of wear of the tire, is the same as that of an actual asphalt-paved road) is formed as the pavement portion 63. The simulated pavement is formed by molding and hardening a simulated pavement material in which a binder, such as urethane resin or epoxy resin, is added to aggregate, such as ceramics with excellent wear resistance, such as silicon carbide or alumina, which is crushed (and further processed, such as polished or etched, if necessary). By using such a simulated pavement material, a simulated road surface with excellent durability and stable road surface conditions (i.e., the amount of wear of the test tire T is stable) can be obtained. The amount of wear of the tire can be adjusted, for example, by the particle size of the aggregate or the amount of binder added.

[0098] Although the simulated pavement in this embodiment has a single layer structure, it is also possible to use a simulated pavement in which, for example, multiple layers made of different materials are laminated in the thickness direction. Also, it is also possible to use a simulated pavement that simulates a paving stone pavement, a brick pavement, a concrete pavement, or the like, by adjusting, for example, the type and granularity of the aggregate, the type and amount of the binder, or the like.

[0099] In addition, the road surface 63a may be formed so as to cause more (or less) damage to the tires than an actual road surface. By using the road surface 63a that has a greater effect on the tires than an actual road surface, accelerated tire deterioration testing can be performed.

[0100] The pavement 63 may be formed from an actual pavement material (for example, an asphalt mixture used for the surface layer of an asphalt pavement). The pavement 63 may be a reproduction or imitation of an actual pavement, not only for the outermost layer that forms the road surface, but also for the sub-layer structure.

[0101] In the tire testing device 1 of the present embodiment, since the road surface 63a does not move during testing, the test can be performed in a state where foreign matter that affects tire performance (for example, water, snow, muddy water, soil, sand, gravel, oil, or simulants thereof) is scattered on the road surface 63a. For example, a wet braking test can be performed by performing the test in a state where water is scattered on the road surface 63a.

[0102] (First Modification) FIG. 12 is a cross-sectional view of a first modified example (road surface portion 60A) of the road surface portion 60. The road surface portion 60A has a frame portion 67 attached to a base 62. The frame portion 67 is watertightly joined to the base 62 by caulking or the like, and forms a tank 68 together with the base 62. Foreign matter that affects tire performance (e.g., water, gravel, soil, fallen leaves, etc.) is placed in the tank 68 so as to cover the road surface 63a. By using the tank 68, it is possible to deposit a thick layer of foreign matter on the road surface 63a. Note that the frame portion 67 of this modified example is attached to the upper surface of the base 62, but the frame portion 67 may be attached to the side of the base 62. The frame portion 67 may also be attached to the upper surface of the pavement portion 63.

[0103] The road surface portion 60A is also provided with a temperature adjustment means 64 capable of adjusting the temperature of the road surface 63a. The temperature adjustment means 64 of this modified example has a flow path 64a embedded in the base 62, a temperature sensor 64b for detecting the temperature of the road surface 63a, and a temperature adjustment device 64c (FIG. 10). The temperature sensor 64b is, for example, a contact type temperature sensor using a thermocouple or a thermistor, or a non-contact type temperature sensor such as an infrared sensor. The temperature adjustment device 64c is connected to the control unit 72 and adjusts the temperature of the road surface 63a to a set temperature based on a command from the control unit 72. Specifically, the temperature adjustment device 64c adjusts the temperature of a heat medium (for example, water containing oil or antifreeze) based on the detection result of the temperature sensor 64b, and sends this heat medium to the flow path 64a. The heat medium whose temperature has been adjusted by the temperature adjustment device is caused to flow through the flow path 64a, thereby adjusting the road surface 63a to a predetermined temperature. In addition, the surface of the base 62 is covered with a heat insulating material 69 in order to stabilize the temperature of the road surface 63a and to increase the efficiency of heat utilization.

[0104] The temperature adjustment means 64 can adjust the temperature of the road surface 63a in a wide range from low (e.g., -40°C) to high (e.g., 80°C). A frozen road surface can be formed by storing water in the tank 68 and setting the set temperature of the road surface 63a below freezing. That is, by using the road surface portion 60A of this modified example, it is possible to perform braking tests on ice. Also, with snow put in the tank 68, it is possible to perform braking tests on snow.

[0105] The flow paths 64a are formed parallel to the road surface 63a and meander at equal intervals within the base 62. The base 62 is divided into a plurality of sections (base units 620) in the length direction, and each section is provided with an individual flow path 64a. This configuration makes it possible to adjust the temperature of the entire road surface 63a to a more uniform temperature.

[0106] (Second Modification) Next, a description will be given of a second modified example (road surface portion 60B) of the road surface portion 60. The road surface portion 60B is provided with a load detection portion 65 that detects the distribution of the load that the road surface receives from the tire tread of the test wheel W.

[0107] Fig. 13 is a cross-sectional view of the road surface portion 60B, and Figs. 14 and 15 are a cross-sectional view and a plan view, respectively, of the load detection portion 65 of the road surface portion 60B and its surroundings.

[0108] A deep recess 621a (Figure 14) that is deeper than the surrounding areas is formed at approximately the center of the bottom of the recess 621 formed in the upper surface of the base 62 of the road surface portion 60B in the length direction (X-axis direction) and width direction (Y-axis direction).

[0109] As shown in FIG. 14, the deep recess 621a is not filled with the pavement 63, and a plurality of load detection modules 650 constituting the load detection unit 65 are laid in the deep recess 621a. The plurality of load detection modules 650 are arranged in a lattice pattern in two directions, the X-axis direction and the Y-axis direction. In this modification, 150 load detection modules 650 are arranged at equal intervals (e.g., 100 mm intervals) in 15 rows in the X-axis direction and 10 rows in the Y-axis direction, and fixed to the bottom of the deep recess 621a. The width of the deep recess 621a (i.e., the width of the load detection unit 65) is sufficiently wider than the tread width of the test tire T, so that the entire tire tread of the test tire T can be grounded on the load detection unit 65.

[0110] As shown in FIG. 14, the load detection module 650 is configured by attaching a paving section 652 to the upper surface of a piezoelectric three-component force sensor 651. The three-component force sensor 651 is a cylindrical piezoelectric element whose central axis faces the Z-axis direction. The paving section 652 is a rectangular parallelepiped member whose lengths in the X-axis direction and the Y-axis direction are equal. The three-component force sensor 651 and the paving section 652 may have other shapes. For example, the three-component force sensor 651 may have a rectangular parallelepiped shape, and the paving section 652 may have a cylindrical shape. The three-component force sensor 651 and the paving section 652 may have the same shape. The upper surface of the paving section 652 is disposed perpendicular to the Z-axis to form a road surface.

[0111] The paved portion 652 of this modification is formed of the same material as the paved portion 63 and with the same thickness as the paved portion 63. However, the material and size of the paved portion 652 may be different from those of the paved portion 63. Also, the paved portion 652 may not be provided, and the upper surface of the load detection module 650 may be used as the road surface. In this case, the depth of the deep recess 621a may be determined so that the upper surface of the load detection module 650 is at the same height as the upper surface of the paved portion 63.

[0112] The three-component force sensor 651 detects the following three types of forces f applied to the road surface 652a of each load detection module 650 (i.e., applied to the tire tread): R , f T and f L The time change of is detected. a) radial force f R b) Tangential force f T c) Lateral force f L

[0113] By using the load detection unit 65, it is possible to detect the distribution of the force that the road surface receives from the tire tread of the test tire T (that is, the force applied to the tire tread) and its change over time.

[0114] Various processes are performed to generate final load profile data (measured values ​​of the load profile) based on the load distribution (initial load profile) detected by the load detection unit 65. The load profile measurement results are displayed on the display device of the control system 1a as, for example, a three-dimensional CG image, and the load distribution applied to the tire tread is visualized.

[0115] In the following description, the load distribution detected by the load detection unit 65 (or the load detection unit 165 described later) is referred to as the detected load distribution (or the detected value of the load distribution), and the load distribution finally obtained by various processing based on the detected load distribution is referred to as the measured load distribution (or the measured value of the load distribution).

[0116] In this modified example, the above three types of forces f R , f T and fL Image data of three profile images representing the respective distributions of the above are generated, and the two profile images are displayed side by side on the screen of a display device either simultaneously or by switching between them in sequence.

[0117] The load distribution is detected continuously at regular time intervals (for example, 5 millisecond intervals) by all the load detection modules 650 at the same time. The load measured by each load detection module 650 is associated with measurement data measured by the six-component force sensor 282 of the spindle 280 at the same timing, and is recorded in the storage device 721 of the control unit 72 (or the server 77 connected to the control unit 72 via, for example, a LAN).

[0118] When tire testing is performed using a tire testing apparatus 1 equipped with the road surface section 60B of this modified example, the six-component force sensor 282 on the test wheel W side and the load detection section 65 on the road surface side can simultaneously measure the load applied to the test wheel W and the road surface, making it possible to obtain more detailed data regarding the behavior of the tire tread during driving that could not be obtained with conventional tire testing apparatuses.

[0119] In this modified example, the load detection portion 65 is provided only in the approximate center in the length direction and width direction of the road surface portion 60B, but the load detection portion 65 may be provided on the entire surface of the road surface portion 60B.

[0120] (Third Modification) Next, a description will be given of a third modified example (road surface portion 60C) of the road surface portion 60. The road surface portion 60C of this modified example is also provided with a load detection unit 165 that detects the distribution of the load that the road surface receives from the tire tread of the test wheel W.

[0121] 16 and 17 are a plan view and a side view, respectively, showing the load detection unit 165 of the road surface portion 60C and its surroundings, while Figs. 18-20 are a front view, a left side view, and a plan view, respectively, of the load detection unit 165.

[0122] 16 and 17, a recess 60p extending in the Y-axis direction is formed on the upper surface of the main body 60a of the road surface portion 60C. The load detection portion 165 is housed in the recess 60p and fixed to the bottom surface of the recess 60p.

[0123] As shown in Figs. 18-20, the load detection section 165 includes a fixed frame 1658, a movable frame 1659, a pair of linear guides 1653, a sensor array unit 1650, a moving unit 1655, and a sensor position detection section 1656. Note that in Fig. 18, the linear guides 1653 and a rail support section 1658b of the fixed frame 1658, which will be described later, are omitted from illustration. The movable frame 1659 is supported by the pair of linear guides 1653 so as to be movable in the Y-axis direction (i.e., the width direction of the road surface section 60C). The sensor array unit 1650 is attached to the upper surface of the movable frame 1659. The sensor array unit 1650 will be described in detail later.

[0124] FIG. 21 is a plan view showing the load detection section 165 with the movable section (that is, the movable frame 1659 and the sensor array unit 1650) removed.

[0125] 19 and 21, the fixed frame 1658 includes a substantially rectangular base plate 1658a and a pair of rail support parts 1658b fixed to the upper surface of the base plate 1658a. The pair of rail support parts 1658b are arranged at an interval in the X-axis direction with their length directions aligned in the Y-axis direction.

[0126] The linear guide 1653 includes a rail 1653a extending in the Y-axis direction and a plurality of (three in this modification) carriages 1653b (hereinafter referred to as "runners 1653b") that can run on the rail 1653a. The rail 1653a is attached to the upper surface of a rail support portion 1658b. The runners 1653b are attached to the lower surface of a movable frame 1659. The linear guide 1653 guides the movement of the movable frame 1659 in the Y-axis direction.

[0127] The moving unit 1655 is disposed between the pair of rail support portions 1658b and the linear guide 1653. The moving unit 1655 includes a motor 1655m and a ball screw mechanism 1655b. The ball screw mechanism 1655b includes a ball screw 1655ba, a nut 1655bb, a bearing portion 1655bc, and a bearing portion 1655bd.

[0128] The ball screw 1655ba is rotatably supported at both ends by a pair of bearings 1655bc and 1655bd. One end of the ball screw 1655ba is connected to the shaft of a motor 1655m. A nut 1655bb that meshes with the ball screw 1655ba is attached to the lower surface of the movable frame 1659. When the ball screw 1655ba is rotated by the motor 1655m, the movable frame 1659 and the sensor array unit 1650 move in the Y-axis direction together with the nut 1655bb. 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.

[0129] 21, the sensor position detection unit 1656 includes a movable arm 1656a, a plurality of (three in this modification) proximity sensors 1656c, and a sensor attachment unit 1656b. The movable arm 1656a and the sensor attachment unit 1656b in this modification are each formed by sheet metal processing, but may be formed by other processing methods (for example, cutting, casting, resin injection molding, etc.). The movable arm 1656a has an end fixed to a movable frame 1659 and is movable in the Y-axis direction together with the movable frame 1659. The sensor attachment unit 1656b is attached to a fixed frame 1658.

[0130] The multiple proximity sensors 1656c are attached to the sensor attachment portion 1656b. The multiple proximity sensors 1656c are arranged in the Y-axis direction with their detection surfaces 1656cf facing the positive direction of the X-axis. In this modification, the multiple proximity sensors 1656c are arranged at equal intervals in the Y-axis direction.

[0131] A proximity portion 1656ap that is close to the proximity sensor 1656c is formed at the tip of the movable arm 1656a. In this modification, the proximity portion 1656ap is formed by bending the tip of the movable arm 1656a into a crank shape. The proximity portion 1656ap is disposed at the same height as the detection surfaces 1656cf of the multiple proximity sensors 1656c. In addition, the detection surfaces 1656cf of the multiple proximity sensors 1656c are disposed at intervals within the movable range of the proximity portion 1656ap in the Y-axis direction.

[0132] Fig. 22 is an enlarged view of an area E surrounded by a two-dot chain line in Fig. 18. As shown in Fig. 18 and Fig. 22, the sensor array unit 1650 includes a frame 1650a and a plurality of (150 in this modification) load detection modules 1650m. A recess 1650ap that is long in the Y-axis direction is formed in the center of the upper surface 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.

[0133] The load detection modules 1650m are arranged at equal intervals (for example, with almost no gaps) in two directions, the X-axis direction and the Y-axis direction. In this modification, 150 load detection modules 1650m are arranged in 5 rows in the X-axis direction and 30 rows in the Y-axis direction.

[0134] The load detection module 1650m includes a three-component force sensor 1651, a paving portion 1652, and a bolt 1653. The three-component force sensor 1651 and the paving portion 1652 are the same members as the three-component force sensor 651 and the paving portion 652 of the second modified example, respectively.

[0135] A hole 1651b penetrating in the Z-axis direction is formed in the center of the cylindrical three-component force sensor 1651. A bolt hole 1652b extending in the Z-axis direction is formed in the center of the pavement 1652. The load detection module 1650m is integrated and fixed to the frame 1650a by a bolt 1653 passed through the hole 1651b of the three-component force sensor 1651 and screwed into the bolt hole 1652b of the pavement 1652. The upper surface of the pavement 1652 is disposed horizontally to form a road surface 1652a. The area in the X-axis and Y-axis directions in which the load detection modules 1650m are arranged becomes the detection area of ​​the sensor array unit 1650.

[0136] As shown in Fig. 10, the motor 1655m of the moving unit 1655 is connected to the control unit 72 via the driver 1655a. The three-component force sensor 1651 and the proximity sensor 1656c of the sensor position detection unit 1656 are connected to the measurement unit 74 via the preamplifier 1651a and the preamplifier 1656ca, respectively. Note that in Fig. 10, only one each of the three-component force sensor 1651, the preamplifier 1651a, the proximity sensor 1656c, and the preamplifier 1656ca is shown. The signals from the three-component force sensor 1651 and the proximity sensor 1656c are amplified by the preamplifiers 1651a and 1656ca, respectively, and then converted to digital signals in the measurement unit 74.

[0137] Next, a procedure for changing the position of the sensor array unit 1650 in the Y-axis direction by the moving unit 1655 will be described. In the initial state shown in Fig. 21, the sensor array unit 1650 is disposed at a position where the proximity part 1656ap of the movable arm 1656a faces the detection surface 1656cf of the central proximity sensor 1656c. For example, when a command is issued to move the sensor array unit 1650 to the left (positive direction of the Y-axis) by a user operation on the touch screen, the control unit 72 transmits a counterclockwise rotation command to the driver 1655a so that the sensor array unit 1650 moves in the positive direction of the Y-axis. The driver 1655a that receives the counterclockwise rotation command supplies a driving current to the motor 1655m for counterclockwise rotation. When the motor 1655m is driven counterclockwise by a drive current, the ball screw 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 frame 1659 in the positive direction of the Y axis.

[0138] When the sensor array unit 1650 moves in the positive direction of the Y axis, the proximity part 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 stops detecting the proximity. Eventually, the proximity part 1656ap of the movable arm 1656a reaches a position facing the detection surface 1656cf of the left (positive Y axis) proximity sensor 1656c. At this time, the left proximity sensor 1656c detects the proximity and outputs a proximity signal indicating the detection of the proximity. The measurement unit 74, which has received the proximity signal via the preamplifier 1656ca, notifies the control unit 72 that the sensor array unit 1650 has reached the fixed position on the left side. The control unit 72, which has received the notification from the measurement unit 74, transmits a command to stop driving to the driver 1655a. The driver 1655a, which has received the command to stop driving, stops supplying the driving current to the motor 1655m. As a result, the shaft of motor 1655m and ball screw 1655ba stop rotating, and the nut 1655bb and sensor array unit 1650 also stop, completing the movement of sensor array unit 1650.

[0139] By installing the moving unit 1655, it is possible to shorten the length Ly of the detection area of ​​the sensor array unit 1650 in the Y-axis direction, thereby reducing the number of load detection modules 1650m required to measure the load distribution, thereby reducing the costs required for manufacturing and maintaining the sensor array unit 1650.

[0140] Next, there will be described a method for acquiring the distribution of the load applied to the tire tread using the load detection unit 165. Fig. 23 is a flowchart showing the steps of the method for acquiring the distribution of the load applied to the tire tread.

[0141] When the power switch of the tire testing apparatus 1 is turned on, the control unit 72 first performs an initialization process S1. As shown in FIG. 2, in the initial state, the carriage 20 is in an initial position (initial running position) P1 set near the end of its movable range in the negative X-axis direction. X0 The slide frame 44 (FIG. 4) is disposed at an initial position P Z0 It is placed at the initial position P Z0 At this point, the test wheel W rises from the road surface 63a, making it possible to attach / detach the test wheel W and adjust its alignment. In addition, the slip angle and camber are adjusted to preset values ​​by the slip angle adjustment unit 46 and the camber adjustment unit 47, respectively.

[0142] With the test wheel W lifted off the road surface 63a, the servo motor 32 of the torque applying device 30 is driven to rotate the test wheel W to a rotational position θ W is the initial rotation position θ W0 The rotational position θ of the torque applying device 30 itself is then moved to the position θ . M Since the belt mechanism 50 and the belt mechanism 23 using toothed belts are used, the travel position P X The rotational position θ is determined by M In the initial state, the torque applying device 30 is always at the initial rotation position θ M0 will be placed in.

[0143] After the initialization process S1 is completed, when an instruction to start the test is given, for example by a user operating the touch screen (S2: YES), the number of measurement sets k is reset to 1 (S3), the test wheel W is lowered by the load adjustment unit 45 so that it touches the road surface 63a, and the set load is applied (S4).

[0144] Next, the first measurement set S5 is performed. In the measurement set S5, the servo motor 141 of each drive unit 14 is driven, the carriage 20 runs at a set running speed, and the test wheel W rotates at a peripheral speed substantially the same as the running speed of the carriage 20. In addition, the servo motor 32 of the torque applying device 30 is driven, and a set torque is applied to the test wheel W.

[0145] In the measurement set S5, the forces applied to the road surface and the test wheel W are detected by the three-component force sensor 1651 of the load detection unit 165 and the six-component force sensor 282 of the spindle unit 28 at predetermined time intervals (for example, 5 millisecond intervals). The time intervals for detection by the three-component force sensor 1651 and the six-component force sensor 282 are appropriately set according to the test conditions (for example, the running speed of the carriage 20 and the required test accuracy).

[0146] In addition, in the measurement set S5, the travel position P X and the rotational position θ of the test wheel W W is calculated at a predetermined time interval. X is calculated from the detection result of the rotary encoder RE (FIG. 10) built in the servo motor 141 of the drive unit 14, the reduction ratio of the reducer 142, and the pitch circle diameter of the drive pulley 52 of the belt mechanism 50. X is the position of the rotation axis Ay of the test wheel W in the running direction of the carriage 20 (X-axis direction).

[0147] Rotational position θ of test wheel W Wis calculated based on the detection results of the rotary encoder 39 of the torque applying device 30 and the rotary encoder RE built in the servo motor 32. Specifically, the rotational position θ W is the rotational position θ of the shaft 321 of the servo motor 32 detected by the rotary encoder RE of the servo motor 32. M (However, the initial rotation position θ M0 is set to 0 [rad].) multiplied by the reduction ratio of the reducer 33 (i.e., the rotational position θ S ) relative to the rotational position θ of the housing 31 of the torque applying device 30 detected by the rotary encoder 39. H It is calculated by adding to

[0148] The rotational position θ of the output from the torque applying device 30 T A detection means such as a rotary encoder for detecting the rotational position θ of the test wheel W (for example, the rotational position of the spindle 280 or the shafts 261 and 263) is provided. W Alternatively, the configuration may be such that the above is detected directly.

[0149] The detection results of the three-component force sensor 1651 and the six-component force sensor 282 are detected at the same timing by the rotary encoder RE built in the servo motor 141 of the drive unit 14 (i.e., the travel position P X ) and the rotational position θ of the test wheel W W The detected force is stored in the storage device 721 of the control unit 72 (or in a storage means accessible by the control unit 72, such as the server 77 connected to the control unit 72 via a LAN) in association with the detection result. Note that the detection result by the three-component force sensor 1651 may be configured to record only the period when the test wheel W passes through the sensor array unit 1650 and a specified period before and after that. This makes it possible to reduce the amount of data to be stored.

[0150] When the carriage 20 reaches the end of the travel section and stops, the load adjustment unit 45 raises the test wheel W to a height at which the test wheel W rises above the road surface 63a (for example, the same height as in the initial state) (S6). Then, the drive unit 14 is driven to move the carriage 20 to the initial position P X0 (S7).

[0151] The above steps S4 to S7 are repeated until the number of measurement sets k reaches the specified number of times n (S8). If the number of measurement sets k has not reached the specified number of times n (S8: NO), the servo motor 32 of the torque applying device 30 is driven to change the rotational position θ W is the rotational position θ W0 +k*Δθ W In other words, each time the number of measurement sets k is increased by one, the initial position P X0 Rotational position θ of test wheel W at W is the angular width Δθ W is changed one by one.

[0152] Angle width Δθ W is, for example, the central angle θ of the test wheel W corresponding to the length Lx (FIG. 19) of the detection area of ​​the sensor array unit 1650 in the X-axis direction. C1 (That is, the rotation angle θ when the test wheel W rolls the distance Lx C1 ) is set to the following value. For example, the angular width Δθ W is the central angle θ of the test wheel W corresponding to the arrangement interval δ of the load detection module 1650 m (Figure 19). C2 The same value as the central angle θ C2 is set to a value slightly smaller than

[0153] In addition, the angle width Δθ W may 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 thoroughly by the n-time measurement set.

[0154] When the measurement set is completed the prescribed number n (S8: YES), the load profile calculation S10 is then performed.

[0155] 24 is a flowchart showing the procedure of the load profile calculation S10. The load profile calculation S10 is a process of calculating load profile data based on the measurement results acquired by the n measurement sets S5.

[0156] The load profile data is based on three types of forces acting on the tire: radial force f R , tangential force f T and lateral force f L ) is data associated with planar coordinates on the road surface.

[0157] In the load profile calculation S10, first, the coordinates of each load detection module 1650m are calculated (S101). The coordinates of the center point of the upper surface of the load detection module 1650m are defined as the coordinates of the load detection module 1650m.

[0158] 25 is a plan view showing the positional relationship between the load detection module 1650m and the rotation axis Ay of the test wheel W. As described above, in this modified example, 150 load detection modules 1650m are arranged in 5 rows in the X-axis direction and 30 rows in the Y-axis direction. In the following description, the row number of the load detection modules 1650m in the X-axis direction is p, the row number of the load detection modules 1650m in the Y-axis direction is q, and the arrangement of the load detection modules 1650m is represented by a pair of positive integers [p, q] (hereinafter referred to as "address [p, q]").

[0159] In addition, the (x, y) coordinate system is used in the load profile calculation S10. The (x, y) coordinate system is a two-dimensional Cartesian coordinate system parallel to the (X, Y) coordinate system, with the center of the upper surface of the load detection module 1650m located at address [3, 1] as its origin. That is, the xy plane is the plane on which the road surface of the road surface portion 60C is located. In addition, in the description of this modified example, coordinates with a fixed point as the origin are called absolute coordinates, and coordinates with a movable 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.

[0160] In this modification, the load detection modules 1650m are arranged at equal intervals δ in the x-axis direction and the y-axis direction. Therefore, the x and y coordinates of the address [p, q] are calculated by the following equations. x = (p-3)*δ y = (q-1)*δ

[0161] Next, the x-coordinate of the rotation axis Ay of the test wheel W (hereinafter referred to as "coordinate x Ay The coordinate x of the rotation axis Ay is calculated (S102). Ay is calculated by the following formula: x Ay = P X - S X however, P X : Running position P of test wheel W X (X coordinate of rotation axis Ay) S X : X coordinate of the position (y axis) of the sensor array unit 1650

[0162] That is, in step S102, the coordinates of the rotation axis Ay of the test wheel W are converted from the XY coordinate system to the xy coordinate system.

[0163] Next, the running position P of the test wheel W X The relative position (relative coordinates) of the load detection module 1650m based on the rotation axis Ay is calculated (S103). r ,y r ) is calculated by the following formula: In this modification, a load profile for the relative position is obtained. x r = x - x Ay y r = y

[0164] Next, all the measurement results (i.e., the radial force f measured by each load detection module 1650m) areR , tangential force f T and lateral force f L ) to the relative coordinate (x r ,y r ) to obtain three types of forces f R , f T and f L In step S104, the load profile data may be calculated as an approximate curved surface obtained by regression analysis (for example, curved surface fitting such as the least squares method).

[0165] In step S104, the rotational position θ of the test wheel W W The load profile data may be calculated taking into account the rotational position θ W In this case, the load profile data may be calculated taking into account the symmetry of the tread pattern of the test tire T about the rotation axis Ay. Specifically, the load profile data may be calculated based on the rotational position θ W Load profile data may be calculated for each.

[0166] In this modification, the measurement is performed for only one revolution of the test wheel W by n measurement sets, but it is also possible to increase the number of measurement sets and perform measurements for multiple revolutions. X0 Rotational position θ of test wheel W at W The central angle θ of the test wheel W corresponding to the arrangement interval δ of the load detection module 1650 m C2 Since multiple measurement sets are performed while changing the angle by one step, the resolution of the load profile data in the x-axis direction is about the arrangement interval δ of the load detection modules 1650 m. C2 1 / 10 of the rotation position θ W By repeatedly performing the measurement set while changing the central angle θ, the effective resolution in the x-axis direction can be made finer than the arrangement interval δ of the load detection modules 1650m. For example, C2 The rotation position θ WIf the measurement set is repeated while changing, the effective resolution in the x-axis direction can be reduced to about δ / m.

[0167] In this modification, the length Lx 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, the entire load distribution of the tire tread cannot be obtained by rolling the test wheel W on the sensor array unit 1650 only once.

[0168] Therefore, in this modified example, the rotational position θ of the test wheel W when rolling on the sensor array unit 1650 W In this method, the load distribution on the tire tread is measured multiple times while shifting the load detection module 1650. This makes it possible to shorten the length of the detection area of ​​the sensor array unit 1650 in the X-axis direction and reduce the number of load detection modules 1650m required to measure the load distribution, thereby reducing the costs required for manufacturing and maintaining the sensor array unit 1650.

[0169] Furthermore, the effective resolution in the y-axis direction can be reduced by repeatedly performing measurement sets while changing the y-axis position of the sensor array unit 1650 by a predetermined interval using the moving unit 1655. In this case, a motor capable of controlling the position (e.g., a servo motor or a stepping motor) is used as the motor 1655m of the moving unit 1655. For example, the effective resolution in the y-axis direction can be reduced to about 1 mm by repeatedly performing measurement sets while changing the y-axis position of the sensor array unit 1650 by 1 mm.

[0170] Next, the calculated load profile is displayed on the display device of the interface unit 76. FIG. 26 shows an example of a load profile display. FIG. 26(a) shows the tangential force f T , Figure 26(b) shows the lateral force f L , Figure 26(c) shows the radial force f R The load profile image shown in FIG. 26 shows the load profile image at each position (xr ,y r ) converted to lightness.

[0171] The above is a description of the embodiment of the present invention. The embodiment of the present invention is not limited to the above description, and various modifications are possible. For example, the embodiment of the present application also includes a configuration that appropriately combines the configurations of the embodiments etc. exemplified in this specification and / or the configurations of the embodiments etc. that are obvious to a person skilled in the art from the description in this specification.

[0172] Although the tire testing apparatus 1 includes two belt mechanisms 50 in the above embodiment, it may include one belt mechanism 50 or three or more belt mechanisms 50.

[0173] In the above embodiment, the belt mechanism 50 is driven by the power generated by a pair of drive units 14, but it may be configured to be driven by one drive unit 14 or three or more drive units 14.

[0174] In the above embodiment, toothed belts and toothed pulleys are used for each of the belt mechanisms 50, 23, and 24, but a flat belt or a V-belt may be used instead of the toothed belt for one or more of the belt mechanisms. Also, instead of the belt mechanisms, other types of winding transmission mechanisms such as a chain transmission mechanism or a wire transmission mechanism, or other types of power transmission mechanisms such as a ball screw mechanism, a gear transmission mechanism, or a hydraulic mechanism may be used.

[0175] In the above embodiment, the power to drive the carriage 20 and the power to drive the test wheel W (spindle 280) are supplied by a common drive unit 14 and transmitted by a common belt mechanism 50, but the present invention is not limited to this configuration. For example, the power to drive the carriage 20 and the power to drive the test wheel W may be generated by separate drive units and transmitted by separate power transmission means (for example, separate belt mechanisms). In this case, in order to match the running speed of the carriage 20 and the circumferential speed of the test wheel W, it is necessary to synchronously control the drive of the drive unit for driving the carriage and the drive unit for driving the test wheel.

[0176] In the above embodiment, a simple drive system and control system are realized by sharing parts (drive unit 14 and belt mechanism 50) of the mechanism (carriage drive means) that drives the carriage 20 and the mechanism (test wheel drive means) that drives the test wheel W. Sharing the carriage drive means and the test wheel drive means (particularly sharing the drive unit 14) is made possible by introducing the torque applying device 30 and separating the power sources for speed control and torque control of the test wheel W, thereby reducing the load on the drive unit 14.

[0177] In the third variant described above, the initial position P Z0 Rotational position θ of test wheel W at W By changing the initial position P, it is possible to measure the load profile of the tire tread that is longer than the length Lx of the detection area of ​​the sensor array unit 1650 in the X-axis direction. However, by providing a means for changing the position of the sensor array unit 1650 in the X-axis direction, Z0 Rotational position θ of test wheel W at W This makes it possible to measure the load profile of the tire tread longer than the length Lx without changing the length L. The means capable of changing the position of the sensor array unit 1650 in the X-axis direction can be configured, for example, by a position-controllable motor and a feed screw mechanism (for example, a ball screw mechanism) similar to the moving unit 1655. <Overview> The following is an overview of the embodiments of the present invention. According to one embodiment of the present invention, there is provided a tire testing apparatus comprising: a road surface portion having a road surface; and a carriage that rotatably holds a test wheel equipped with a test tire and is capable of running along the road surface with the test wheel in contact with the road surface, wherein at least a portion of the road surface portion is constituted by a replaceable road surface unit. In the above tire testing apparatus, the road surface portion may include a base and a pavement portion provided on the base and having the road surface formed on its surface, and at least a portion of the pavement portion may be configured to be composed of at least one of the road surface units. In the above tire testing apparatus, the road surface portion may include a main body portion having a base and a pavement portion provided on the base and having the road surface formed on its surface, and at least a part of the main body portion may be configured to be composed of at least one of the road surface units. In the tire testing apparatus described above, the road surface portion may include a frame portion that forms a tank together with the base plate. In the tire testing apparatus described above, the road surface may be a simulated road surface made of a material different from the surface of an actual road. The above tire testing apparatus may further comprise a drive system for driving the test wheel and the carriage, the drive system comprising: carriage drive means for driving the carriage at a predetermined speed relative to the road surface; test wheel drive means for driving the test wheel at a rotation speed corresponding to the predetermined speed; drive means for generating power used to drive the carriage and the test wheel; and power distribution means for distributing the power generated by the drive means to the carriage drive means and the test wheel drive means. According to one embodiment of the present invention, there is provided a tire testing apparatus comprising: a carriage that rotatably holds a test wheel equipped with a test tire and that can run along a road surface with the test wheel in contact with the road surface; and a drive system that drives the test wheel and the carriage, wherein the drive system comprises carriage drive means that drives the carriage at a predetermined speed relative to the road surface, test wheel drive means that drives the test wheel at a rotation speed corresponding to the predetermined speed, drive means that generates power used to drive the carriage and the test wheel, and power distribution means that distributes the power generated by the drive means to the carriage drive means and the test wheel drive means. The tire testing apparatus may further comprise a drive system for driving the test wheel and the carriage, the drive system comprising: drive means for generating power used to drive the carriage and the test wheel; and a first wrapping transmission mechanism for transmitting the power generated by the drive means, the first wrapping transmission mechanism comprising: a drive pulley coupled to an output shaft of the drive means; a driven pulley held by the carriage and connected to the test wheel; and a first wrapping medium node stretched across the drive pulley and the driven pulley, the first wrapping medium node having a first part and a second part stretched in the running direction of the carriage and driven in opposite directions to each other, the first part passing through the driven pulley, and the second part fixed to the carriage. According to one embodiment of the present invention, there is provided a tire testing apparatus comprising: a carriage that rotatably holds a test wheel having a test tire and that can run along a road surface with the test wheel in contact with the road surface; and a drive system that drives the test wheel and the carriage, wherein the drive system comprises drive means that generates power used to drive the carriage and the test wheel, and a first wrapping transmission mechanism that transmits the power generated by the drive means, and the first wrapping transmission mechanism comprises a drive pulley connected to an output shaft of the drive means, a driven pulley that is held by the carriage and connected to the test wheel, and a first wrapping medium node that is stretched between the drive pulley and the driven pulley, and the first wrapping medium node has a first part and a second part that are stretched in the running direction of the carriage and driven in opposite directions to each other, passes through the driven pulley at the first part, and is fixed to the carriage at the second part. In the tire testing apparatus described above, the drive system may include a secondary power transmission unit connected to the first wrapping transmission mechanism and transmitting a portion of the power transmitted by the first wrapping transmission mechanism to the drive wheel, and the driven pulley may be coupled to an input shaft of the secondary power transmission unit. In the tire testing apparatus described above, the drive system may include a pair of the drive means, the first winding transmission mechanism may include a pair of the drive pulleys respectively coupled to output shafts of the pair of drive means, and the first winding intermediate node may form a loop and be stretched around the pair of drive pulleys and the driven pulley. In the tire testing apparatus described above, the first winding intermediate node may be a toothed belt having a core wire of a steel wire. In the tire testing apparatus described above, the first winding intermediate node may be a toothed belt having a carbon core wire. The tire testing apparatus may further comprise a drive system for driving the test wheels and the carriage, the drive system comprising a test wheel drive means for driving the test wheels, the test wheel drive means comprising two drive means for generating power for driving and rotating the test wheels, and a power combining means for combining the power generated by the two drive means, and the two drive means may include a first motor installed on the base and a second motor installed on the carriage. In the tire testing apparatus described above, the test wheel driving means may include two of the driving means and a power combining means for combining the power generated by the two driving means, and the two driving means may include a first motor installed on the base and a second motor installed on the carriage. In the tire testing apparatus described above, the drive system may include a test wheel drive means for driving the test wheels, the test wheel drive means may include two of the drive means and a power combining means for combining power generated by the two drive means, and the two drive means may include a first motor installed on the base and a second motor installed on the carriage. The tire testing apparatus may further comprise a drive system for driving the test wheel and the carriage, the drive system comprising a test wheel drive means for driving the test wheel, the test wheel drive means comprising a rotational motion supply means for supplying a rotational motion with a number of rotations corresponding to the speed of the carriage, and a torque applying means for changing the phase of the rotational motion supplied from the rotational motion supply means to apply a predetermined torque to the test wheel. In the tire testing apparatus described above, the test wheel driving means may include a rotational motion supplying means for supplying a rotational motion having a number of rotations corresponding to the speed of the carriage, and a torque applying means for changing the phase of the rotational motion supplied from the rotational motion supplying means to apply a predetermined torque to the test wheel. In the tire testing apparatus described above, the drive system may include a test wheel drive means for driving the test wheel, and the test wheel drive means may include a rotational motion supply means for supplying a rotational motion with a number of rotations corresponding to the speed of the carriage, and a torque applying means for changing the phase of the rotational motion supplied from the rotational motion supply means to apply a predetermined torque to the test wheel. According to one embodiment of the present invention, there is provided a tire testing apparatus comprising: a carriage that rotatably holds a test wheel equipped with a test tire and that can run on a base along a road surface with the test wheel in contact with the road surface; a drive system that drives the test wheel and the carriage, the drive system comprising test wheel drive means that drives the test wheel, the test wheel drive means comprising rotational motion supply means that supplies rotational motion with a number of rotations corresponding to the speed of the carriage, and torque imparting means that changes the phase of the rotational motion supplied from the rotational motion supply means to impart a predetermined torque to the test wheel. In the tire testing apparatus described above, the rotational motion supplying means may include a first motor mounted on the base, and the torque applying means may include a second motor mounted on the carriage. In the tire testing apparatus described above, the torque applying means may include power combining means for combining the power generated by the first motor and the power generated by the second motor. In the tire testing apparatus described above, the torque applying means may include a rotating frame to which the second motor is attached and which is rotationally driven by power generated by the first motor, and a shaft driven by the second motor, the shaft and the rotating frame being concentrically arranged. In the tire testing apparatus described above, the torque applying means may include a pair of bearing portions rotatably supporting the rotating frame, the rotating frame being cylindrical and having a motor accommodating portion accommodating the second motor, and a pair of shaft portions having a smaller diameter than the motor accommodating portion and provided on both axial sides of the motor accommodating portion, the pair of shaft portions being rotatably supported by the pair of bearing portions, one of the shaft portions being cylindrical, the shaft passing through a hollow portion thereof, and a bearing for rotatably supporting the shaft being provided on an inner circumference of the shaft portion. In the tire testing apparatus described above, the secondary power transmission unit may include a second shaft driven by the torque applying means, a bearing that rotatably supports the second shaft, and a sliding type constant velocity joint that connects the second shaft and the spindle. In the above tire testing apparatus, the test wheel drive means may include a primary power transmission unit that transmits the power supplied from the rotational motion supply means, and a secondary power transmission unit that is installed on the carriage and connected to the primary power transmission unit to transmit the power transmitted by the primary power transmission unit to the test wheel, the primary power transmission unit including a first wrapping transmission mechanism, the first wrapping transmission mechanism including a pair of fixed pulleys arranged on either side of an area in which the carriage can run, a movable pulley held by the carriage, and a first wrapping intermediate node stretched between the pair of fixed pulleys and the movable pulley, and at least one of the fixed pulleys is a driving pulley connected to an output shaft of the rotational motion supply means, and the movable pulley is a driven pulley connected to an input shaft of the secondary power transmission unit. In the above tire testing apparatus, the secondary power transmission unit may include a second wrapping transmission mechanism, and the second wrapping transmission mechanism may include a drive pulley connected to the moving pulley of the first wrapping transmission mechanism, a driven pulley connected to the rotating frame of the torque applying means, and a second wrapping intermediate node stretched across the drive pulley and driven pulley of the second wrapping transmission mechanism. In the tire testing apparatus described above, the secondary power transmission unit may include a rotatably supported spindle, the test wheel may be coaxially attached to a tip of the spindle so as to be detachable, and a force sensor may be provided to detect the force applied to the test wheel. In the above tire testing apparatus, the carriage may include a main frame, a rotating frame capable of rotating relative to the main frame about a vertical line perpendicular to the road surface, and a slide frame capable of sliding relative to the main frame in a vertical direction perpendicular to the road surface, and the spindle may be supported on the main frame via the rotating frame and the slide frame. In the tire testing apparatus described above, the carriage may include a curved guideway that guides the rotation of the swivel frame about the vertical line, and a linear guideway that guides the movement of the slide frame in the vertical direction. In the tire testing apparatus described above, the slide frame may be configured to support the spindle rotatably about a horizontal axis perpendicular to both a center line of the spindle and the vertical line. In the tire testing apparatus described above, the carriage may include a load adjustment unit that is capable of adjusting the load applied to the test wheel by moving the slide frame in the vertical direction. In the tire testing apparatus described above, the carriage may include a slip angle adjustment unit that is capable of adjusting the slip angle of the test wheel relative to the road surface by rotating the rotating frame about the vertical line. The tire testing apparatus may further include a camber adjustment unit that is capable of adjusting the camber of the test wheel relative to the road surface by rotating the spindle about the horizontal axis. According to one embodiment of the present invention, there is provided a tire testing apparatus comprising: a carriage that rotatably holds a test wheel having a test tire and that can run on a base along a road surface with the test wheel in contact with the road surface; a drive system that drives the test wheel and the carriage, wherein the drive system comprises a test wheel drive means that drives the test wheel, the test wheel drive means comprising two drive means that generate power to drive and rotate the test wheel, and a power combining means that combines the power generated by the two drive means, wherein the two drive means include a first motor installed on the base and a second motor installed on the carriage. In the tire testing apparatus described above, a load detection unit may be provided on the upper surface of the road surface portion to detect a load distribution received by the tire tread of the test wheel. In the tire testing apparatus described above, the load detection unit may include a plurality of load detection modules arranged in a lattice pattern in the running direction of the carriage and the axial direction of the test wheel. In the tire testing apparatus, each of the load detection modules may include a three-component force sensor. The above tire testing apparatus may further include a measuring means for measuring load distribution based on the detection results by the load detection unit, and the measuring means may calculate the radial force, tangential force and lateral force acting on the tire tread based on the detection results of the three-component force sensor. The tire testing apparatus may further include a storage means for storing the detected load distribution. The tire testing apparatus may further include a means for acquiring the running position of the test wheel in the running direction of the carriage, and the memory means may store the detected load distribution in association with the running position of the test wheel at the time the load distribution was detected. The tire testing apparatus may further include a means for acquiring a rotational position of the test wheel, and the memory means may store the detected load distribution and the rotational position of the test wheel at the time the load distribution was detected, in association with each other. In the tire testing apparatus described above, the storage means may store the load distribution and the force applied to the test wheel, which are detected at the same time, in association with each other. The tire testing apparatus may further include a means for calculating a relative position of the load detection module based on the running position of the test wheel, and a measurement value of the load distribution for the relative position is calculated. The load distribution may be detected a number of times while the carriage is running, and the results of the multiple load distribution detections may be averaged for each relative position to calculate the measurement value of the load distribution. In the tire testing apparatus described above, the load distribution measurement value may be calculated by regression analysis. In the tire testing apparatus described above, a configuration may be adopted in which one set of measurements is performed by the load detection unit as the carriage travels in one direction, and the measurement value of the load distribution is calculated based on the results of multiple sets of measurements by the load detection unit. The tire testing apparatus may further include a means for changing the position of the load detection unit in the axial direction of the test wheel. The tire testing apparatus may further include a means for changing the position of the load detection unit in the running direction.

Claims

1. A road surface portion having a road surface; a carriage that rotatably holds a test wheel equipped with a test tire and that is capable of running along the road surface with the test wheel in contact with the road surface; Equipped with At least a portion of the road surface portion is composed of a replaceable road surface unit, The road surface portion is The foundation and a pavement portion provided on the base and having the road surface formed on its surface; The pavement is composed of a plurality of replaceable pavement units divided in the extension direction of the pavement. Tire testing equipment.

2. A road surface portion having a road surface; a carriage that rotatably holds a test wheel equipped with a test tire and that is capable of running along the road surface with the test wheel in contact with the road surface; Equipped with At least a portion of the road surface portion is composed of a replaceable road surface unit, The road surface portion is The foundation and A pavement portion provided on the base and having the road surface formed on its surface; a body portion having a The main body is composed of a plurality of replaceable main body units divided in the extension direction of the main body. Tire testing equipment.

3. The main body unit is a replaceable base unit obtained by dividing the base in an extension direction; A replaceable pavement unit obtained by dividing the pavement in the extension direction; Equipped with 3. A tire testing apparatus according to claim 2.

4. The road surface portion includes a frame that supports the main body portion, The main body unit is placed on the frame and detachably attached.

4. A tire testing apparatus according to claim 2 or 3.

5. The frame is composed of a plurality of replaceable frame units obtained by dividing the frame in the extension direction.

5. A tire testing apparatus according to claim 4.

6. The road surface unit is The frame unit; The base unit; The pavement unit, The road surface portion is formed by connecting a plurality of the road surface units. A tire testing apparatus according to claim 5 which indirectly relies on claim 3.

7. A road surface portion having a road surface; a carriage that rotatably holds a test wheel equipped with a test tire and that is capable of running along the road surface with the test wheel in contact with the road surface; Equipped with The road surface portion is The road surface section is formed by connecting a plurality of replaceable road surface section units obtained by dividing the road surface section in an extension direction, The road surface unit can be extended or shortened by adding or removing the road surface unit. Tire testing equipment.

8. a track portion on which the carriage runs, The raceway portion is composed of a plurality of replaceable raceway portion units obtained by dividing the raceway portion in an extension direction, The road surface unit and the track unit are integrated to form a composite unit, The road surface portion and the track portion can be extended, shortened or partially replaced in units of the composite unit.

8. A tire testing apparatus according to claim 7.

9. The road surface portion is The foundation and A pavement portion provided on the base and having the road surface formed on its surface. A tire testing apparatus according to claim 7 or 8.

10. The road surface portion includes a frame portion that forms a tank together with the base. A tire testing apparatus according to any one of claims 1 to 6 and 9.

11. The road surface is a simulated road surface formed of a material different from the road surface of an actual road. A tire testing apparatus according to any one of claims 1 to 10.

12. a drive system for driving the test wheel and the carriage; The drive system comprises: a carriage driving means for driving the carriage at a predetermined speed relative to the road surface; a test wheel driving means for driving the test wheel at a rotational speed corresponding to the predetermined speed; a first drive means for generating power used to drive the carriage and the test wheel; a power distribution means for distributing the power generated by the first driving means to the carriage driving means and the test wheel driving means; Equipped with A tire testing apparatus according to any one of claims 1 to 11.

13. the first driving means is mounted on the base; The drive system comprises: a second driving means disposed on the carriage; and a power coupling means for coupling the power generated by the first and second driving means.

13. A tire testing apparatus according to claim 12.

14. The test wheel drive means a rotational motion supplying means for supplying a rotational motion having a number of rotations corresponding to the speed of the carriage; and a torque applying means for applying a predetermined torque to the test wheel by changing the phase of the rotational motion supplied from the rotational motion supply means. A tire testing apparatus according to claim 12 or 13.

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