Tire testing device

Abstract

To improve the efficiency of a tire test.SOLUTION: According to an embodiment of the present invention, a tire testing device is provided, comprising: a rotating drum that is provided with a simulated road surface on its outer periphery; and a pair of tire holding parts that rotatably hold test tires in contact with the simulated road surface. The pair of tire holding parts include a first tire holding part that holds a first test tire, and a second tire holding part that holds a second test tire. The tire testing device can simultaneously test the first and second test tires.SELECTED DRAWING: Figure 12

Description

[Technical field]

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

[0002] Tire wear tests to evaluate tire wearability include actual driving tests in which a test tire is mounted on an actual vehicle and driven on an actual road surface under specified conditions to examine the tire wear that occurs during the test. In addition, there are bench tests (simulated tests) as described in Patent Document 1, in which the tire is worn down by rotating a rotating drum and the tire with the tire in contact with the outer circumferential surface of a rotating drum (simulated road surface). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 57-91440 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of one aspect of the present invention is to provide a tire testing apparatus capable of applying torque fluctuations to a test specimen. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided a tire testing apparatus comprising: a rotating drum having a simulated road surface on its outer periphery; a rotational drive unit which rotates and drives the rotating drum; a tire holding unit which rotatably holds a test tire in contact with the simulated road surface; a torque generating unit which generates a torque which applies a braking force or driving force to the test tire; and a relay unit which relays the transmission of power from the rotational drive unit to the torque generating unit, wherein the torque generating unit comprises a rotatably supported case and an electric motor attached to the case, the rotational drive unit rotates and drives the case, and the relay unit comprises a shaft connected to the rotating drum and a gear box which connects the shaft and the case of the torque generating unit, and the shaft and the torque generating unit are arranged side by side.

[0006] In the tire testing apparatus described above, the gear box may include a first gear coupled to the shaft, and a second gear coupled to a case of the torque generating portion and meshing with the first gear.

[0007] In the tire testing apparatus, the test tire is connected to the shaft of the electric motor, The rotating drum, the relay unit, and the torque generating unit may be connected in an annular shape via the test tire to form a power circulation circuit.

[0008] According to another aspect of the present invention, there is provided a tire testing apparatus comprising: a rotating drum having a simulated road surface on its outer periphery; a rotary drive unit having a first electric motor that rotates and drives the rotating drum; a pair of tire holding units that rotatably hold a test tire in contact with the simulated road surface; a pair of torque generating units that generate torque to apply braking or driving force to each test tire; and a relay unit that relays the transmission of power from the rotary drive unit to each torque generating unit, wherein the torque generating units comprise a rotatably supported case and a second electric motor attached to the case, the rotary drive unit rotates and drives the case of the torque generating units, and the relay unit comprises a shaft connected to the rotating drum and a gear box that connects the shaft to the case of each torque generating unit, and the shaft and the pair of torque generating units are arranged side by side.

[0009] In the above tire testing apparatus, the gear box may include a first gear coupled to the shaft, and a pair of second gears coupled to cases of the respective torque generating portions and meshing with the first gear.

[0010] In the above tire testing apparatus, the test tire may be connected to the shaft of the corresponding second electric motor, and the rotating drum, relay unit and each torque generating unit may be connected in a ring shape via the corresponding test tire to form a power circulation circuit. Effect of the Invention

[0011] According to one aspect of the present invention, there is provided a tire testing apparatus capable of applying torque fluctuations to a test specimen. [Brief description of the drawings]

[0012] [Figure 1] 1 is a plan view of a tire testing device according to an embodiment of the present invention. [Diagram 2] 1 is a front view of a tire testing device according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a right side view of the tire testing device according to the embodiment of the present invention. [Figure 4] 1 is a left side view of a tire testing device according to an embodiment of the present invention. FIG. [Diagram 5] FIG. 2 is a block diagram showing a schematic configuration of a control system. [Figure 6] FIG. 2 is an external view of the simulated road surface unit. [Figure 7] FIG. 2 is a cross-sectional view of the simulated road surface unit. [Figure 8] FIG. 2 is a vertical sectional view of a torque generating portion. [Figure 9] FIG. 4 is a side view of the camber adjustment mechanism. [Figure 11] 1 is a schematic diagram of a two-dimensional profile of a tire tread. [Figure 10] FIG. 2 is a diagram showing a schematic configuration of a slip material spreading device. [Figure 12] FIG. 4 is a plan view of a tire testing device according to a second embodiment of the present invention. [Figure 13] FIG. 4 is a front view of a tire testing device according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same or corresponding components are denoted by the same or corresponding reference numerals, and duplicated description will be omitted.

[0014] 1 to 4 are respectively a plan view, a front view, a right side view, and a left side view of a tire testing apparatus 1 according to an embodiment of the present invention. For ease of explanation, some parts of the tire testing apparatus 1 are omitted in Figs. 2 to 4. Fig. 5 is a block diagram showing a schematic configuration of a control system 1a of the tire testing apparatus 1.

[0015] In the following description, the direction from left to right in Fig. 1 is defined as the X-axis direction, the direction from bottom to top as the Y-axis direction, and the direction perpendicular to the paper surface from front to back as the Z-axis direction, as shown by the coordinates in Fig. 1. The X-axis and Y-axis directions are horizontal directions that are perpendicular to each other, and the Z-axis direction is a vertical direction.

[0016] The tire testing device 1 is a device capable of performing a tire bench test in which the test tire T is worn under conditions similar to those of an actual running test by rotating the rotating drum 22 and the test tire T for a predetermined time (for example, 24 hours) while the test tire T is in contact with the simulated road surface 23b provided on the outer periphery of the rotating drum 22. The tire testing device 1 of this embodiment achieves high energy utilization efficiency by adopting an electric motor and a power circulation system in the drive system. In addition, by adopting a torque generating device described later, it is possible to provide dedicated motors for the two functions of rotational drive and torque application, respectively, and to perform rotation control and torque control independently. This enables high-precision torque control with a high degree of freedom, and also enables the capacity of the electric motor to be reduced, making it possible to reduce the size of the test device and the power consumption. In addition, by using an ultra-low inertia servo motor with excellent acceleration performance in the torque generating device, it is possible to accurately reproduce torque fluctuations having high frequency components during sudden starts and sudden braking.

[0017] The tire testing device 1 includes a tire holding unit 10 that holds a test tire T, a road surface unit 20 having a simulated road surface 23b on which the test tire T comes into contact, a rotation drive unit 30 that rotates and drives a power circulation circuit, a torque generating unit 50 that generates a braking force and a driving force to be applied to the test tire T, and a relay unit 40 that relays the power transmission from the rotation drive unit 30 to the torque generating unit 50. The tire testing device 1 also includes a first connecting means (drive shaft 62) that connects the rotation drive unit 30 and the relay unit 40, a second connecting means (V-belt 66) that connects the relay unit 40 and the torque generating unit 50, and a third connecting means (constant velocity joint 64) that connects the torque generating unit 50 and the tire holding unit 10 (spindle 152). The road surface unit 20, the rotation drive unit 30, the relay unit 40, the torque generating unit 50, and a spindle unit 15 (described later) of the tire holding unit 10 are connected in an annular shape via the test tire T to form a power circulation circuit.

[0018] In this embodiment, the rotating drum 22 is arranged with its rotation axis facing the Y-axis direction, but it may be arranged with its rotation axis facing, for example, the X-axis direction, the Z-axis direction, or an intermediate direction between these (for example, a direction forming an angle of 45° with each of the X-axis and the Z-axis). In this case, the orientation and arrangement of the other components of the tire testing apparatus 1 are also changed according to the orientation of the rotating drum 22.

[0019] As shown in FIG. 5, the control system 1a of the tire testing apparatus 1 includes a central control unit 70 that controls the operation of the entire testing apparatus, a measurement unit 80 that performs various measurements based on signals from various sensors provided in the tire testing apparatus 1, and an interface unit 90 that performs input and output with the outside.

[0020] As shown in Fig. 1-4, the road surface section 20 includes a rotating drum 22, a simulated road surface section 23 provided on the outer periphery of the rotating drum 22, and a bearing section 24 that rotatably supports the shaft 22a of the rotating drum 22. The bearing section 24 includes a rotary encoder 241 (Fig. 5) that detects the number of rotations of the rotating drum 22. The simulated road surface section 23 of this embodiment is formed by a plurality of simulated road surface units 231 (Figs. 6 and 7) that are arranged around the outer periphery of the rotating drum 22 with no gaps in the circumferential direction.

[0021] FIG. 6 is a perspective view of the simulated road surface unit 231 attached to the outer periphery of the rotating drum 22. FIG. 7 is a cross-sectional view of the simulated road surface unit 231 cut along the cut plane AA' shown in FIG. 6. The simulated road surface unit 231 includes a frame 231a, a simulated road surface body 231b (231b1, 231b2) fitted into a recess 231ad formed in the surface of the frame 231a, and a pair of left and right pressing plates 231c that sandwich the simulated road surface body 231b between the frame 231a and fix it to the frame 231a. The pressing plates 231c are fixed to the frame 231a by a plurality of flat head screws 231d. In addition, through holes 231ah are formed at both ends of the frame 231a in the width direction (horizontal direction in FIG. 7) through which bolts for fixing the simulated road surface unit 231 to the rotating drum 22 are passed.

[0022] The simulated road surface 23b is formed by the surfaces of multiple simulated road surface bodies 231b arranged in the circumferential direction. The simulated road surface body 231b in this embodiment is composed of two circumferentially extending portions (a first portion 231b1 in the left half and a second portion 231b2 in the right half in FIG. 7) made of different materials. The first portion 231b1 forms a first driving lane 23b1, which will be described later, and the second portion 231b2 forms a second driving lane 23b2.

[0023] The entire simulated road surface body 231b may be formed uniformly from a single material. Although the simulated road surface body 231b of this embodiment is formed into a smooth cylindrical surface, for example, the thickness of the simulated road surface body 231b may be periodically or randomly changed in the circumferential direction (or in both the circumferential direction and the width direction) to provide unevenness in the circumferential direction (or in both the circumferential direction and the width direction) on the surface.

[0024] In this embodiment, the preformed simulated road surface body 231b is attached to the frame 231a by the pressing plate 231c, but the simulated road surface body 231b may be directly attached to the frame 231a by bolts by providing through holes in the simulated road surface body 231b through which bolts for fixing the simulated road surface body 231b to the frame 231a are passed. Also, the simulated road surface body 231b may be fixed to the surface of the simulated road surface unit 231 by filling the recesses 231ad with a plastic material such as concrete or hardening resin and hardening the material.

[0025] The simulated road surface body 231b is a component made by adding a binder containing a hardening resin such as urethane resin or epoxy resin to an aggregate made by crushing (and polishing, if necessary) highly wear-resistant ceramics such as silicon carbide or alumina, and then molding and hardening the resulting material.

[0026] In this embodiment, the simulated road surface 23b is divided into two travel lanes (a first travel lane 23b1 and a second travel lane 23b2) in the axial direction (width direction) of the rotating drum 22. In this embodiment, two travel lanes are formed on the simulated road surface 23b, but a single travel lane or three or more travel lanes may be formed. The two travel lanes 23b1 and 23b2 of the simulated road surface 23b are formed by changing the particle size and amount of aggregate used. The first travel lane 23b1 on the right side facing the traveling direction is a simulated road surface that simulates a smooth road surface such as an asphalt paved road surface, and the second travel lane 23b2 on the left side is a simulated road surface that simulates a rough road surface such as a cobblestone road surface. The road surface conditions can be changed by switching the travel lanes 23b1 and 23b2 of the simulated road surface 23b on which the test tire T is grounded. The travel lane switching is performed by a traverse mechanism 11 (travel lane switching mechanism) of the tire holding unit 10 described later.

[0027] The rotary drive unit 30 includes a motor 32 and a power coupling unit 34 that couples the power output from the motor 32 to the power circulation circuit. The motor 32 is driven and controlled by an inverter circuit 32a (FIG. 5). A shaft 32b of the motor 32 is coupled to an input shaft 34a of the power coupling unit 34. One end 34b1 of an output shaft 34b of the power coupling unit 34 is coupled to the shaft 22a of the rotating drum 22, and the other end 34b2 of the output shaft 34b is coupled to one end of the drive shaft 62. The output shaft 34b of the power coupling unit 34 constitutes a part of the power circulation circuit, and the output shaft of the motor 32 is coupled to the power circulation circuit via the power coupling unit 34. That is, the power circulation circuit is rotationally driven by the motor 32, and the rotation speed of the power circulation circuit is controlled.

[0028] The relay unit 40 includes a gear box 42, a drive pulley 44, a bearing unit 45 that rotatably supports the shaft of the drive pulley 44, a tension pulley 46 that applies a predetermined tension to the V-belt 66 wound around the drive pulley 44, and a bearing unit 47 that rotatably supports the shaft of the tension pulley 46.

[0029] The gear box 42 includes a first gear 42a coupled to the other end of the drive shaft 62, and a second gear 42b meshing with the first gear 42a. The second gear 42b is coupled to the shaft of the drive pulley 44. In this embodiment, since the first gear 42a and the second gear 42b have the same number of teeth, the gear box 42 converts the rotation input from the drive shaft 62 into a constant speed rotation in the opposite direction and transmits it to the drive pulley 44.

[0030] The first gear 42a and the second gear 42b are replaceable with gears having different numbers of teeth (diameters). For example, the first gear 42a and the second gear 42b may have different numbers of teeth, and the gear box 42 may increase or decrease the rotation speed. In order to make the numbers of teeth of the first gear 42a and the second gear 42b changeable, the distance between the rotation axes of the first gear 42a and the second gear 42b is changeable. Specifically, the position of the rotation axis of the second gear 42b is fixed, and the position of the rotation axis of the first gear 42a is movable horizontally (in the distance direction from the second gear 42b, i.e., in the X-axis direction). When changing the number of teeth of each gear, the position of the rotation axis of the first gear 42a is moved horizontally to adjust the meshing with the second gear 42b. The rotary drive unit 30 (specifically, the other end 34b2 of the output shaft 34b of the power coupling unit 34) and the first gear 42a are connected by a drive shaft 62 having universal joints 621 at both ends and a variable length. Therefore, even if the first gear 42a moves laterally, no distortion occurs in the drive shaft 62 or the first gear 42a, and smooth rotation of the power circulation circuit is maintained.

[0031] 8 is a vertical cross-sectional view of the torque generating unit 50 (torque generating device). The torque generating unit 50 includes an outer cylinder 51 (case), a servo motor 52, a reducer 53, and a shaft 54 ​​mounted inside the outer cylinder 51, three bearings 55, 55, and 56 that rotatably support the outer cylinder 51, a slip ring unit 57 (slip ring 57a, brush 57b), a bearing 58 that rotatably supports the slip ring 57a, and a driven pulley 59.

[0032] In this embodiment, the moment of inertia of the rotating part of the servo motor 52 is 0.01 kg m 2 Below, an ultra-low inertia, high-output AC servo motor with a rated output of 7 kW to 37 kW is used. As shown in Fig. 5, the servo motor 52 is connected to the central control unit 70 via a servo amplifier 52a.

[0033] The outer cylinder 51 has a cylindrical motor accommodating section 512 and a reducer holding section 513, each having a large diameter, and substantially cylindrical shaft sections 514 and 516, each having a small diameter. The shaft section 514 is coaxially coupled (i.e., so that the rotation axes coincide) to one end (the right end in FIG. 8) of the motor accommodating section 512. The shaft section 516 is coaxially coupled to the other end (the left end in FIG. 8) of the motor accommodating section 512 via the reducer holding section 513. The shaft section 514 is rotatably supported by the bearing section 56, and the shaft section 516 is rotatably supported by a pair of bearing sections 55.

[0034] A driven pulley 59 coupled to the shaft portion 516 is disposed between the pair of bearing portions 55. The outer cylinder 51 is rotationally driven by a V-belt 66 (FIG. 1) wound around the driven pulley 59 and the drive pulley 44 of the relay portion 40.

[0035] Bearings 517 are provided on both ends of the inner circumference of shaft portion 516. Shaft 54 ​​is inserted into the hollow portion of shaft portion 516 and is rotatably supported by shaft portion 516 via a pair of bearings 517. Shaft 54 ​​passes through shaft portion 516, with one end protruding into reducer holding portion 513 and the other end protruding outside outer cylinder 51.

[0036] The servo motor 52 is accommodated in the hollow portion of the motor accommodating portion 512. The servo motor 52 has a shaft 521 arranged coaxially with the motor accommodating portion 512, and a motor case is fixed to the motor accommodating portion 512 by a plurality of rods 523. A flange 522 of the servo motor 52 is coupled to a gear case 53a of the reducer 53 via a connecting tube 524. The gear case 53a of the reducer 53 is fixed to an inner flange 513a of the reducer holding portion 513.

[0037] The shaft 521 of the servo motor 52 is connected to an input shaft 531 of the reducer 53. In addition, a shaft 54 ​​is connected to an output shaft 532 of the reducer 53. The torque output from the servo motor 52 is amplified by the reducer 53 and transmitted to the shaft 54. The rotation of the shaft 54 ​​is obtained by adding the rotation of the outer cylinder 51 driven by the motor 32 of the rotation drive unit 30 and the rotation driven by the servo motor 52.

[0038] A slip ring 57a is connected to the shaft portion 514 of the outer cylinder 51. A brush 57b in contact with the slip ring 57a is supported by a fixed frame 58a of a bearing portion 58. A cable 525 of the servo motor 52 is passed through the hollow portion of the shaft portion 514 and connected to the slip ring 57a. The brush 57b is connected to a servo amplifier 52a (FIG. 5). That is, the servo motor 52 and the servo amplifier 52a are connected via the slip ring portion 57.

[0039] Next, the configuration of the tire holding unit 10 will be described with reference to Figs. 1-3 and 9. Fig. 9 is a rear view (partial cross-sectional view) of the tire holding unit 10. The tire holding unit 10 is a mechanism unit that brings the test tire T into contact with the simulated road surface 23b with a predetermined alignment and rotatably holds the test tire T while applying a predetermined load. The tire holding unit 10 includes four base plates 101, 102, 103, and 104 stacked vertically, and a spindle unit 15 that rotatably holds the test tire T. The tire holding unit 10 also includes a traverse mechanism 11, a camber angle adjustment mechanism 12, a tire load adjustment mechanism 13, and a slip angle adjustment mechanism 14 as an alignment mechanism for the test tire T. The alignment mechanism is a mechanism that can adjust the alignment of the test tire T with respect to the simulated road surface 23b by changing the position or direction of the spindle unit 15.

[0040] The traverse mechanism 11 (driving lane switching mechanism) is a mechanism for moving the base plate 102 in the Y-axis direction relative to the base plate 101 to move the position of the test tire T in the axial direction and switch between driving lanes 23b1, 23b2 of the simulated road surface 23b on which the test tire T is grounded. The traverse mechanism 11 includes a plurality of linear guides 111 that guide the base plate 102 in the axial direction (Y-axis direction) of the rotating drum 22 relative to the base plate 101, a servo motor 112 that drives the base plate 102, and a ball screw 113 (feed screw mechanism) that converts the rotational motion of the servo motor 112 into linear motion in the Y-axis direction. The ball screw 113 includes a screw shaft 113a and a nut 113b.

[0041] Each linear guide 111 includes a rail 111a and one or more carriages 111b that can run on the rail 111a via rolling elements (not shown). The rail 111a of the linear guide 111 is attached to the upper surface of the base plate 101, and the carriage 111b is attached to the lower surface of the base plate 102. In other words, the base plate 101 and the base plate 102 are connected to each other via the multiple linear guides 111 so as to be slidable in the Y-axis direction.

[0042] In addition, a servo motor 112 with its axis oriented in the Y-axis direction is attached to the base plate 101. The shaft of the servo motor 112 is coupled to a screw shaft 113a of a ball screw 113, and a nut 113b is attached to the lower surface of the base plate 102. By driving the servo motor 112, the base plate 102 moves in the Y-axis direction relative to the base plate 101. As a result, the position of the test tire T with respect to the rotating drum 22 moves in the Y-axis direction, and the driving lanes 23b1, 23b2 of the simulated road surface 23b on which the test tire T contacts the ground are switched.

[0043] 5, the servo motor 112 is connected to the central control unit 70 via a servo amplifier 112a. The driving lane switching operation by the servo motor 112 is controlled by the central control unit 70.

[0044] 9 is a rear view showing the upper part of the tire holding unit 10. The camber angle adjustment mechanism 12 is a mechanism that adjusts the camber angle of the test tire T by rotating the base plate 103 around the Z axis relative to the base plate 102. The camber angle adjustment mechanism 12 includes a vertically extending shaft 121, a bearing 122 that rotatably supports the shaft 121, a curved guide 123 that guides the rotation of the base plate 103 around the shaft 121, a servo motor 124 attached to the base plate 102 with its axis oriented in the Y axis direction, and a ball screw 125 (feed screw mechanism) that converts the rotational motion of the servo motor 124 into linear motion in the Y axis direction.

[0045] The shaft 121 is attached to the base plate 103, and the bearing 122 is attached to the base plate 102. The bearing 122 is provided with a rotary encoder 122a (camber angle detection means) shown in FIG. 5 for detecting the angular position (i.e., camber angle) of the shaft 121. The shaft 121 is disposed directly under the ground surface where the test tire T touches the rotary drum 22. Specifically, the center line (rotation axis) of the shaft 121 is a straight line passing through the ground surface perpendicular to the spindle 152. The curved guide 123 includes a rail 123a extending in an arc shape concentric with the shaft 121, and a carriage 123b capable of running on the rail 123a via a rolling element (not shown). The rail 123a is attached to the upper surface of the base plate 102, and the carriage 123b is attached to the lower surface of the base plate 103. Furthermore, a screw shaft 125a of the ball screw 125 is coupled to the shaft of a servo motor 124, and a nut 125b is attached to the base plate 103 via a hinge 126 that can swing around a vertical axis. By driving the servo motor 124, the base plate 103 rotates around the shaft 121, and the camber angle of the test tire T changes.

[0046] 5, the servo motor 124 is connected to the central control unit 70 via a servo amplifier 124a. The adjustment operation of the camber angle by the servo motor 124 is controlled by the central control unit 70.

[0047] The tire load adjustment mechanism 13 is a mechanism for adjusting the vertical load (ground pressure) applied to the test tire T by moving the base plate 104 in the X-axis direction relative to the base plate 103, thereby moving the test tire T in the radial direction. The tire load adjustment mechanism 13 includes a plurality of linear guides 131 that guide the base plate 104 in the radial direction (X-axis direction) of the rotating drum 22 relative to the base plate 103, a servo motor 132 that drives the base plate 104, and a ball screw 133 (feed screw mechanism) that converts the rotational motion of the servo motor 132 into linear motion in the X-axis direction.

[0048] The linear guide 131 includes a rail 131a extending in the X-axis direction and a carriage 131b that can run on the rail via rolling elements. The rail 131a of the linear guide 131 is attached to the upper surface of the base plate 103, and the carriage 131b is attached to the lower surface of the base plate 104.

[0049] In addition, a servo motor 132 with its axis oriented in the X-axis direction is attached to the base plate 103. The shaft of the servo motor 132 is coupled to a screw shaft 133a of a ball screw 133, and a nut 133b is attached to the base plate 104. By driving the servo motor 132, the base plate 104 moves together with the nut 133b in the X-axis direction relative to the base plate 103. This changes the axis-to-axis distance between the rotating drum 22 and the test tire T, and the load on the test tire T changes.

[0050] 5, the servo motor 132 is connected to the central control unit 70 via a servo amplifier 132a. The load adjustment operation of the test tire T by the servo motor 132 is controlled by the central control unit 70.

[0051] The slip angle adjustment mechanism 14 is a mechanism for adjusting the slip angle of the test tire T by rotating the spindle portion 15 around the X-axis relative to the base plate 104, thereby tilting the rotation axis of the test tire T around the X-axis relative to the rotation axis of the rotating drum 22.

[0052] The slip angle adjustment mechanism 14 includes a shaft 141 having one end fixed to a spindle case 154 (bearing portion) of the spindle portion 15 and extending in the Y-axis direction, a bearing portion 142 that supports the shaft 141 rotatably around the X-axis (i.e., around an axis perpendicular to the ground contact surface), a servo motor 143, and a ball screw 144 (feed screw mechanism). The bearing portion 142 includes a rotary encoder 142a (FIG. 5) that detects the angular position of the shaft 141 (i.e., the slip angle of the test tire T). The center line (rotation axis) of the shaft 141 passes through the approximate center of the wheel portion 156 and is disposed perpendicular to the rotation axis of the wheel portion 156. The servo motor 143 is attached to the base plate 104 via a hinge 143b that can swing around the Y-axis with the axis facing approximately in the Z-axis direction. The shaft of the servo motor 143 is coupled to a screw shaft 144a of the ball screw 144. Nut 144b of ball screw 144 is attached to one end of spindle case 154 in the X-axis direction (a location away from the center of shaft 141 in the X-axis direction) via hinge 146 that is swingable around the Y-axis.

[0053] By driving the servo motor 143 to move the nut 144b of the ball screw 144 up and down, the spindle case 154 rotates together with the shaft 141. As a result, the slip angle of the test tire T held by the spindle portion 15 changes.

[0054] 5, the servo motor 143 is connected to the central control unit 70 via a servo amplifier 143a. The adjustment operation of the slip angle by the servo motor 143 is controlled by the central control unit 70.

[0055] The spindle unit 15 includes a spindle 152, a spindle case 154 (bearing unit) that rotatably supports the spindle 152, and a wheel unit 156 that is coaxially attached to one end of the spindle 152. A test tire T is mounted on the wheel unit 156. The spindle 152 includes a torque sensor 152a that detects torque applied to the test tire T, and a three-component force sensor 152b (FIG. 5) that detects three-component forces (i.e., force in the X-axis direction [radial force; load], force in the Y-axis direction [lateral force; lateral force], and force in the Z-axis direction [traditive force; tangential force]) applied to the test tire T. The spindle case 154 also includes a rotary encoder 154b (FIG. 5) that detects the number of rotations of the spindle (i.e., test tire T). Since the torque sensor 152a and the three-component force sensor 152b both use piezoelectric elements, the spindle 152 and the spindle case 154 have high rigidity, which enables highly accurate measurements. In addition, the wheel portion 156 is equipped with an air pressure sensor 156a (FIG. 5) that detects the air pressure of the test tire T.

[0056] The tire holding unit 10 is equipped with a tire temperature adjustment system 18 (only the air supply duct 182a is shown in FIG. 2) that adjusts the temperature of the test tire T by blowing cold or hot air onto the test tire T. The temperature of the test tire T (particularly, the temperature of the tread surface) during the test (during running) affects the test results (amount of wear). Therefore, it is desirable to keep the temperature of the tread surface of the test tire T within a certain temperature range (e.g., 35±5° C.) during the test. Also, in the measurement of the amount of wear of the test tire T described later, the temperature of the test tire T affects the measurement results. In order to accurately measure the amount of wear, it is necessary to adjust the temperature of the test tire T to a predetermined reference temperature (e.g., 25° C.) during the measurement. Therefore, the tire temperature adjustment system 18 is used to adjust the temperature of the test tire T to a set temperature during the test and when the amount of wear is measured.

[0057] The tire temperature adjustment system 18 (FIG. 5) includes a control unit 181, a spot air conditioner 182, and a temperature sensor 183. The temperature sensor 183 is a non-contact temperature sensor (radiation thermometer) that measures the temperature of the tread surface of the test tire T, and is disposed opposite the tread surface. The control unit 181 controls the operation of the spot air conditioner 182 based on the measurement result of the temperature sensor 183 so that deviation from the set temperature is eliminated, and blows cold air, hot air, or air at room temperature onto the tread surface of the test tire T. The set temperature of the test tire T can be set to different values ​​during testing (during running) and during wear measurement. Also, different set temperatures can be set depending on the type of the test tire T. Also, the tire temperature adjustment system 18 may be further provided with a temperature sensor for measuring room temperature, and the operation of the spot air conditioner 182 may be controlled based on the room temperature and the temperature of the test tire T.

[0058] Although the tire temperature regulation system 18 of the present embodiment is configured to regulate the temperature of the test tire T by blowing hot or cold air onto the test tire T using the spot air conditioner 182, the tire temperature regulation system is not limited to this configuration. For example, a cover (constant temperature chamber) that entirely surrounds the test tire T may be provided, and the temperature of the test tire T may be regulated by regulating the air temperature inside the cover.

[0059] The set temperature during testing may be set according to the climate of the region in which the tire is used. Tire wear is accelerated by an increase in temperature. Therefore, an accelerated aging test can be performed by using the tire temperature adjustment system 18 to adjust the temperature of the test tire T during testing to be higher than the temperature of the tire during normal driving.

[0060] The tire holding unit 10 also includes a two-dimensional laser displacement sensor 17 (hereinafter, abbreviated as "displacement sensor 17") used to measure the amount of wear of the tread of the test tire T. The displacement sensor 17 uses a laser beam (laser light sheet) expanded into a strip shape by a cylindrical lens to measure a two-dimensional profile (a cross-sectional shape cut by a plane including the rotation axis of the tire) of the tread surface of the test tire T in a non-contact manner.

[0061] 5, the displacement sensor 17 is connected to a measurement unit 80 and functions as a wear measurement unit together with the measurement unit 80. The measurement unit 80 controls the operation of the displacement sensor 17 and calculates the amount of wear of the test tire T based on the two-dimensional profile acquired by the displacement sensor 17.

[0062] The two-dimensional profile measurement by the wear measurement unit is performed before and after the tire test (and additionally during the test) with the test tire T stationary. The amount of wear of the test tire T caused by the test is calculated based on the two-dimensional profiles measured before, during and after the test. As described above, the measured amount of tire wear is affected by the tire temperature, so when performing measurement after the test is completed (or stopped), it is desirable to perform the test after the entire tire has reached a predetermined reference temperature by natural heat dissipation or forced cooling by the tire temperature adjustment system 18.

[0063] Fig. 10 is a schematic diagram of a two-dimensional profile of the tread surface of test tire T obtained by two-dimensional profile measurement using a wear measuring unit. In Fig. 10, the horizontal axis (Y) indicates the position in the width direction of test tire T, and the vertical axis (H) indicates the position in the height direction (radial direction of test tire T) of the groove of test tire T. Four grooves G1, G2, G3, and G4 extending in the circumferential direction are formed in test tire T. By image analysis of the two-dimensional profile, U-shaped recessed portions in the two-dimensional profile are associated with each of the grooves G1 to G4.

[0064] Further, in a predetermined range on both sides of each groove G1 to G4 in the width direction (Y-axis direction), neighborhood regions L1 and R1, L2 and R2, L3 and R3, and L4 and R4 are respectively set. Hereinafter, the n-th groove is indicated by the symbol Gn, and the neighborhood regions of the groove Gn are indicated by the symbols Ln and Rn. Moreover, the neighborhood region on the horizontal negative direction side of the groove Gn (left side in FIG. 10) is referred to as the neighborhood region Ln, and the neighborhood region on the horizontal positive direction side of the groove Gn (right side in FIG. 10) is referred to as the neighborhood region Rn. The neighborhood region Ln (Rn) is set, for example, as a region from the left end (right end) of the groove Gn to a distance of half the width of the groove Gn.

[0065] The depth Dn of the groove Gn is calculated as, for example, the difference between the average value of the height H in the adjacent regions Ln and Rn and the average value of the height H in the groove Gn. The wear amount Wn of each groove Gn before and after the test is calculated as the difference between the depth Dn of the groove Gn before and after the test. The average wear amount W of the test tire T is calculated as the average value of the wear amounts W1 to W4.

[0066] In addition to (or instead of) the above groove depth Dn, a minimum groove depth Dn min The minimum groove depth Dn of the groove Gn may be calculated. min is calculated as, for example, the difference between the average value of the minimum value of the height H in the neighboring region Ln and the minimum value of the height H in the neighboring region Rn and the maximum value of the height H in the groove Gn. In this case, the minimum groove depth Dn is calculated as min The wear amount Wn and the average wear amount W may be calculated using the following:

[0067] The method of calculating the wear amount Wn and the average wear amount W is not limited to the above example, and other methods may be used. For example, in the above example, the depth Dn of the groove Gn and the minimum groove depth Dn are calculated using the heights H of both the neighboring regions Ln and Rn. minHowever, the depth Dn of the groove Gn may be calculated using the height H of either one of the neighboring regions Ln and Rn (for example, the one closer to the widthwise center of the test tire T). Also, an approximation curve (for example, a quadratic curve) of a two-dimensional profile may be obtained for the portion of the grooves G1 to G4 and the portion other than the grooves G1 to G4 by the least squares method or the like, and the average wear amount W may be calculated as the difference in average distance between the two approximation curves before and after the test.

[0068] In addition, the wear measuring unit 17 measures the wear amount Wn of each groove Gn and the average wear amount W, as well as the wear amount W per unit travel distance (for example, 1 km). L or the amount of wear per unit of driving time (for example, 1 hour) W T Calculate and display.

[0069] The tire holding unit 10 is equipped with a lubricant spreading device 16 (powder spreading device) that spreads lubricant (target object) on the tread surface of the test tire T and the simulated road surface 23b of the rotating drum 22. The lubricant spreading device 16 spreads a mixture of lubricant dispersed in air from the front in the running direction (upper side in FIG. 1) of the contact area between the test tire T and the simulated road surface 23b. This prevents malfunctions and failures caused by rubber powder generated by wear of the test tire T adhering to various parts of the tire testing device 1. In addition, the spreading of the lubricant reduces the influence of adhesion of rubber powder to the test tire T, the simulated road surface 23b, etc. on the test results, improving the test accuracy.

[0070] For the lubricant, a non-flammable powder such as talc (hydrated magnesium silicate) is used, which prevents dust explosions and eliminates the need for safety measures against dust explosions such as explosion-proof equipment, making it possible to significantly reduce initial and running costs.

[0071] 11 is a diagram showing a schematic configuration of the slip dispersing device 16. The slip dispersing device 16 includes a hopper 161 (storage section) in which the slip is stored, an agitator 162 for agitating the inside of the hopper 161, a drive section 163 for rotating the agitator 162, a quantitative conveying section 164 for conveying a quantitative amount of the slip, an ejector 166 for sucking in the slip, mixing it with air and ejecting it, a pipe 165 for guiding the slip from the quantitative conveying section 164 to the ejector 166, a pipe 167 for guiding the air in which the slip is dispersed from the ejector 166 to the dispersing position, and a trumpet mouth 168 attached to the tip of the pipe 167.

[0072] The stirrer 162 includes a rod 162a extending vertically, three pairs of branches 162b extending radially vertically from the side of the rod 162a toward the inner peripheral surface of the hopper 161, three shoe holders 162c (slider holders) attached to the tip of each pair of branches 162b, and three shoes 162d (sliders) held by the shoe attachments 162c. The rod 162a is disposed concentrically with the cylindrical inner peripheral surface of the hopper 161, and one end of the shoe is connected to the drive unit 163. Each shoe 162d is disposed so that its tip contacts the inner peripheral surface of the hopper 161, and revolves along the inner peripheral surface of the hopper 161 while scraping off the lubricant adhering to the inner peripheral surface of the hopper 161. In this embodiment, a brush formed of, for example, a conductive (or antistatic) resin is used as the shoe 162d. When the tire testing apparatus 1 is in operation, the agitator 162 constantly agitates the lubricant in the hopper 161. This prevents fluctuations in the supply amount of the lubricant and interruptions in supply due to the lubricant clumping and clogging in the hopper 161. Since the lubricant easily adheres to the inner circumferential surface of the hopper 161 and becomes a starting point for clumping, clogging of the lubricant is effectively prevented by rubbing the inner circumferential surface of the hopper 161 with the tip of the shoe 162d, enabling a stable supply of the lubricant.

[0073] In this embodiment, a brush is used as the shoe 162d, but a member other than a brush (for example, a sponge or sheet having rubber elasticity) may be used as the shoe 162d. The shoe 162d is pressed against the inner peripheral surface of the hopper 161 with an appropriate force due to the elasticity of the shoe 162d, and the slipping material adhered to the inner peripheral surface of the hopper 161 is scraped off. If the shoe 162d does not have an appropriate elasticity, the shoe attachment portion 162c or the branch portion 162b may be made elastic. For example, by using a leaf spring for the branch portion 162b, the shoe 162d can be pressed against the inner peripheral surface of the hopper 161 by the elastic force of the leaf spring. Furthermore, by using a shoe 162d made of resin or rubber, scratches and wear on the inner peripheral surface of the hopper 161 due to the sliding of the shoe 162d are prevented.

[0074] Furthermore, by using the shoe 162d made of a conductive material (for example, synthetic resin with carbon black mixed in), accumulation of lubricant on the surface of the shoe 162d due to static electricity is prevented.

[0075] The drive unit 163 includes a motor 163m, a driver 163md (FIG. 5) that supplies a drive current to the motor 163m, and a reducer 163g that reduces the rotation speed of the output of the motor 163m.

[0076] The axes of the hopper 161 and the stirrer 162 are oriented vertically in this embodiment, but may be oriented in the up-down direction (that is, the axes may be inclined relative to the vertical).

[0077] The fixed quantity conveying unit 164 includes a cylindrical case 164a having a cylindrical hollow portion, a substantially cylindrical screw 164b concentrically accommodated in the hollow portion of the case 164a, and a driving unit 164c that drives and rotates the screw 164b. The driving unit 164c includes a servo motor 164cm and a servo amplifier 164cma that supplies a driving current to the servo motor 164cm. Instead of the servo motor 164cm, another type of motor that can control the rotation speed may be used.

[0078] The screw 164b has a generally cylindrical body 164b1 with a helical groove formed on the outer circumference, and a shaft 164b2 that extends from both axial ends of the body 164b1 in the axial direction and is thinner than the body 164b1. In addition, bearing holes 164a1 that rotatably engage with the shaft 164b2 are formed at both axial ends of the case 164a. The shaft of the drive unit 164c is connected to one side of the shaft 164b2.

[0079] Openings are provided at both axial ends of the case 164a. One opening, an inlet 164a2, is formed on the upper surface at one end of the case 164a. The other opening, an outlet 164a3, is formed on the lower surface at the other end of the case 164a. The inlet 164a2 is connected to the discharge port of the hopper 161, and the outlet 164a3 is connected to a straight pipe 164d extending vertically.

[0080] A single helical groove is formed on the outer periphery of the screw 164b. The helical groove has a semicircular cross section. In this embodiment, the pitch of the helical groove is constant, but it may be an unequal pitch. Also, a plurality of helical grooves (multiple helical structures) may be formed on the screw 164b. The outer diameter of the main body 164b1 of the screw 164b is slightly smaller than the inner diameter of the hollow part of the case 164a. If the gap between the outer periphery of the screw 164b and the inner periphery of the case is narrow, the gap will be filled with lubricant, increasing frictional resistance, and conversely, if the gap is wide, the conveying efficiency will decrease.

[0081] By the rotation of the screw 164b, the lubricant moves from the inlet 164a2 to the outlet 164a3 in the hollow part of the case 164a, and is discharged from the straight pipe 164d. Since the amount of lubricant transported per rotation of the screw 164b is constant, it is possible to continuously supply the lubricant at a constant speed by rotating the screw 164b at a constant speed. In addition, it is possible to adjust the supply speed of the lubricant by changing the rotation speed of the screw 164b.

[0082] The ejector 166 is driven by compressed air supplied from piping 166a, and by spraying compressed air at high speed from a built-in nozzle toward the discharge side, it creates negative pressure in the suction port to which the pipe 165 is connected, sucking the lubricant from the suction port, and ejects air in which the lubricant is dispersed from the discharge port to which the pipe 167 is connected.

[0083] The inlet of the pipe 165 is disposed vertically opposite to the outlet of the straight pipe 164d of the fixed quantity conveying unit 164 with a gap G therebetween. Air flows into the pipe 165 from the gap G due to the negative pressure generated by the ejector 166. The lubricant dropped from the outlet of the straight pipe 164d is introduced into the pipe 165 by the air flowing in from the gap G.

[0084] Moreover, the tip (horn 168) of the duct 167 is disposed directly above the contact area between the test tire T and the simulated road surface 23b. Air containing lubricant ejected from the ejector 166 passes through the duct 167 and is ejected from the horn 168 toward the contact area. Moreover, as shown in FIG. 11, the test tire T and the rotating drum 22 are rotationally driven in a direction in which the contact area moves downward. That is, the lubricant is ejected toward the contact area from the front in the running direction.

[0085] By using the lubricant spreading device 16 described above to spread lubricant in front of the contact area between the test tire T and the simulated road surface 23b, rubber debris generated by wear of the test tire T is prevented from adhering to the test tire T and the tire testing apparatus 1, and a decrease in test accuracy and a breakdown of the tire testing apparatus 1 due to the adhesion of rubber debris are prevented.

[0086] 5, the motor 163m of the drive unit 163 of the skid spreader 16 and the servo motor 164cm of the fixed-quantity conveying unit 164 are connected to the central control unit 70. The operation of the skid spreader 16 is controlled by the central control unit 70.

[0087] 5, the interface unit 90 of the control system 1a includes, for example, a user interface for inputting and outputting with a user, a network interface for connecting to various networks such as a LAN (Local Area Network), and one or more of various communication interfaces such as a USB (Universal Serial Bus) or a GPIB (General Purpose Interface Bus) 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 or a touch pad, a touch screen, a video camera, a printer, a scanner, a buzzer, a speaker, a microphone, a memory card reader / writer, etc.

[0088] The measurement unit 80 is connected to the displacement sensor 17, the rotary encoders 122a, 142a, 154b and 241, the torque sensor 152a, the three-component force sensor 152b, the air pressure sensor 156a and the temperature sensor 183. Based on the signals of each sensor, the measurement unit 80 measures the torque, load (radial force), tangential force (tractive force) and lateral force (lateral force) applied to the test tire T, the number of revolutions of the test tire T, the camber angle, the slip angle, the temperature and air pressure of the tread surface, and the number of revolutions of the rotating drum 22 and the road surface speed (the peripheral speed of the rotating drum 22), and transmits these measured values ​​to the central control unit 70. The road surface speed is calculated from the number of revolutions of the rotating drum 22 measured by the rotary encoder 241.

[0089] The central control unit 70, in accordance with the settings, displays the measurement values ​​obtained from the measuring unit 80 on the display device, and also stores them in the non-volatile memory 71 together with the time of measurement.

[0090] The central control unit 70 is connected to the servo motors 52, 112, 124, 132, 143, and 164cm via the servo amplifiers 52a, 112a, 124a, 132a, 143a, and 164cma, respectively. The central control unit 70 is also connected to the motors 32 and 163m via the inverter circuit 32a and the driver 163md, respectively. The central control unit 70 is also connected to the spot air conditioner 182 and the temperature sensor 183 via the control unit 181 of the tire temperature adjustment system 18.

[0091] In a test using the tire testing apparatus 1 of this embodiment, a tire with a reference design (hereinafter referred to as a "reference tire") is subjected to an actual running test to check the wear state when the tire is fitted to an actual vehicle and driven, and the test conditions are adjusted so that the same wear state as in the actual running test is reproduced in the bench test using the tire testing apparatus 1, and tires of various designs are tested under the adjusted test conditions (hereinafter referred to as "adjusted test conditions"). The reference tire is selected from tires having a design relatively close to that of the tire to be tested. For example, a reference tire is set for passenger car tires and bus / truck tires, respectively.

[0092] According to the embodiment of the present invention described above, since an electric motor is used instead of a hydraulic device, it is possible to greatly reduce the amount of electricity used compared to conventional test devices.

[0093] In addition, since the power consumption is low, the tire testing apparatus 1 can be operated stably even when the power supply is restricted due to a large-scale disaster or the like.

[0094] Furthermore, since no hydraulic device is used, there is no risk of environmental pollution caused by hydraulic oil.

[0095] In addition, since rubber tires deteriorate in quality when they come into contact with hydraulic oil, it is difficult to perform accurate testing in a testing environment contaminated with hydraulic oil. By using the tire testing device 1 of this embodiment, the test tire T is not contaminated with hydraulic oil, so more accurate testing can be performed.

[0096] In this embodiment, the torque generating unit 50 (torque generating device) has a moment of inertia of 0.01 kg m 2 Below, by using an ultra-low inertia, high-output AC servo motor with a rated output of 22kW (7kW to 37kW), it is possible to generate sudden torque fluctuations and accurately reproduce torque changes with complex waveforms.

[0097] Furthermore, in conventional power circulation systems, torque is first applied to the power circulation circuit, and rotational drive is started in the state in which torque is applied, so that the torque cannot be changed during testing and only a constant torque can be applied. In the tire testing device 1 of this embodiment, a torque generating device equipped with an ultra-low inertia, high-output AC servo motor is incorporated into the power circulation circuit, making it possible to apply complex torque fluctuations at high speed (high frequency) to the test specimen while it is running at high speed, and to accurately simulate tests under harsh and complex conditions such as sudden acceleration and deceleration while running at high speed, and ABS brake tests.

[0098] In addition, in the conventional configuration using a single drive motor, the drive motor is required to rotate at high speed and high torque, so a large-capacity motor of 600 kW or more is required even for testing passenger car tires. However, by adopting the torque generating device of this embodiment, the role of each motor is divided into low-speed and high-torque driving and high-speed and low-torque driving, so that the capacity of the servo motor 52 of the torque generating unit 50 is sufficient at 22 kW, and the capacity of the motor 32 of the rotation driving unit 30 is also sufficient at 37 kW, so that a total capacity of 60 kW is sufficient, and it is possible to reduce the required electricity consumption to about 1 / 10. Note that, in a test device suitable for testing truck and bus tires, the electricity consumption is reduced to about 1 / 13. In addition, when a hydraulic motor is used, electricity is used to manage the temperature of the hydraulic oil even when not in operation, but since an electric motor consumes almost no electricity when it is at rest, the actual electricity consumption can be reduced to about 1 / 15.

[0099] Furthermore, by using a motor with a low capacity, it is possible to reduce manufacturing costs and also to make the device more compact.

[0100] In addition, in the tire testing device 1 of this embodiment, the simulated road surface 23b is formed using a novel composite material, which improves the durability of the simulated road surface 23b and enables a reduction in running costs. Furthermore, by using the simulated road surface 23b of this embodiment, it becomes possible to perform tests that accurately simulate various road surfaces by changing the aggregate and binder.

[0101] Second embodiment Next, a second embodiment of the present invention will be described. Fig. 12 and Fig. 13 are a plan view and a front view, respectively, of a tire testing apparatus 1000 according to the second embodiment of the present invention. For ease of explanation, each drawing shows a part of the tire testing apparatus 1000 in cross section. Also, components common to or corresponding to the first embodiment are given the same or corresponding reference numerals, and duplicate explanations will be omitted.

[0102] The tire testing apparatus 1000 of the present embodiment is configured so that it is possible to test passenger car tires and bus / truck tires using a single testing apparatus.

[0103] The tire testing apparatus 1000 is equipped with two power circulation circuits (power circulation circuit A, power circulation circuit B) that share a part of the relay section 1040 (gear box 1042, shaft 1049) and the road surface section 1020 (rotating drum 1022), and is configured to be able to simultaneously test two test tires T1 and T2.

[0104] In addition, in this embodiment, the rotary drive unit 1030 is installed on the frame 1020F of the road surface unit 1020, and the power of the motor 1032 is configured to be transmitted to each power circulation circuit A, B via a drive pulley 1034 connected to the shaft of the motor 1032, a V-belt 1068, and a driven pulley 1025 connected to the shaft 1022a of the rotating drum 1022, and the rotating drum 1022.

[0105] The relay sections 1040A and 1040B are each provided with two sets of driving pulleys 1044A and 1044B and driven pulleys 1048A and 1048B. One set has a reduction ratio suitable for testing passenger car tires, and the other set has a reduction ratio suitable for testing bus and truck tires. The V-belts 1066A and 1066B are wound around the pulley pair for passenger car tires when testing passenger car tires, and are wound around the pulley pair for bus and truck tires when testing bus and truck tires. The reduction ratio can be changed to suit various tires simply by changing the V-belts 1066A and 1066B.

[0106] The relay unit 1040 includes one first gear 1042a and two second gears 1042b. A through hole is provided at the center of each of the first gear 1042a and the second gear 1042b. A shaft 1041A, 1041B having a driven pulley 1048A, 1048B attached to one end thereof passes through the through hole in a non-contact manner. The other end of the shaft 1041A, 1041B is connected to the shaft 1051A, 1051B of the torque generating unit 1050A, 1050B. Each second gear 1042b is coupled to the outer cylinder 1051 of the torque generating unit 1050A, 1050B.

[0107] The above is a description of one embodiment of the present invention. The embodiment of the present invention is not limited to the above-described embodiment, 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.

[0108] In the above embodiment, the position of the rotation shaft of the first gear 42a of the relay unit 40 is configured to be movable laterally, but the position of the rotation shaft of the second gear 42b may be configured to be movable laterally. In this case, the second gear 42b and the drive pulley 44 are connected by, for example, a drive shaft 62 equipped with a universal joint so that the movement of the second gear 42b is permitted.

[0109] In the above embodiment, a V-belt is used as the second connecting means, but a flat belt, a toothed belt, or other belts may be used as the second connecting means. Also, a chain, a wire, or other winding intermediate joint may be used as the second connecting means. Also, in the above first embodiment, the relay unit 40 and the torque generating unit 50 are connected by one V-belt, but they may be connected by multiple second connecting means connected in parallel or in series. Also, when multiple second connecting means are connected in series, different types of second connecting means may be used in combination.

[0110] The above-mentioned embodiments of the present invention will be summarized below.

[0111] In a tire testing apparatus for carrying out a simulation test as described in JP-A-57-91440, rubber debris generated by tire wear adheres to various parts of the tire testing apparatus and can cause breakdowns of the tire testing apparatus.

[0112] The present invention has been made in consideration of the above circumstances, and has an object to prevent rubber debris generated during tire wear tests from adhering to a tire testing device or test tires, thereby preventing breakdowns in the tire testing device.

[0113] According to one embodiment of the present invention, there is provided a tire testing method including a grounding step of grounding a test tire on a simulated road surface provided on the outer periphery of a rotating drum, a rotation step of rotating the rotating drum and the test tire grounded on the simulated road surface, and a powder scattering step of scattering a powder that makes it difficult for rubber debris generated by wear of the test tire to adhere to the outer periphery of at least one of the rotating drum and the test tire.

[0114] In the above tire testing method, the powder scattering step may include a transporting step of transporting the powder at a constant rate, a dispersing step of dispersing the transported powder into gas, and a spraying step of spraying the gas in which the powder is dispersed onto the outer peripheral surface.

[0115] In the above tire testing method, in the spraying step, the gas having dispersed therein the powder may be sprayed toward the contact portion between the simulated road surface and the test tire from the front in the running direction.

[0116] In the tire testing method described above, in the conveying step, a screw as the conveying means may be rotated at a predetermined speed to convey the powder at a constant rate.

[0117] In the above tire testing method, the dispersion step may include a compressed gas supply step of supplying compressed gas to an ejector, a step of sucking the powder by a negative pressure generated by the ejector, and an ejection step of ejecting the powder dispersed in the gas from the ejector.

[0118] In the tire testing method described above, the dispersing step may include a guiding step of guiding the gas ejected from the ejector to a position where the gas is sprayed through a pipeline, and the powder may be more uniformly dispersed in the gas in the guiding step.

[0119] In the above tire testing method, the spraying step may be configured to spray the gas in which the powder is dispersed from a horn.

[0120] In the above tire testing method, the powder may contain talc.

[0121] In addition, according to another embodiment of the present invention, a spraying device is provided which includes a conveying unit that quantitatively transports the object to be sprayed, and an ejector that sucks up the object to be sprayed transported by the conveying unit and ejects gas in which the object to be sprayed is dispersed.

[0122] According to this configuration, a spraying device is provided that can spray the target material quantitatively (for example, continuously at a constant amount per unit time).

[0123] In the above-mentioned spraying device, the conveying section may be configured to include a screw, a cylindrical case that houses the screw, and a drive section that rotates the screw at a predetermined rotation speed.

[0124] In the above-mentioned spraying device, the screw may be a substantially cylindrical member having a helical groove formed on its outer circumferential surface.

[0125] The above-mentioned spraying device may be configured to include a hopper in which the material to be sprayed is stored, with the case having an inlet opening upward at one axial end of the case and a hopper discharge outlet formed at the bottom of the hopper connected to the inlet.

[0126] The above-mentioned spraying device may be configured to include an agitator for agitating the material to be sprayed in the hopper, the hopper having a cylindrical inner surface, and the agitator having a slider that rotates while in contact with the inner surface of the hopper.

[0127] In the above-mentioned spraying device, the agitator may be configured to include a rod that is arranged concentrically with the inner peripheral surface of the hopper and rotates around the axis of the inner peripheral surface, a branch portion that extends from the side of the rod toward the inner peripheral surface of the hopper, and a slider holding portion that is attached to the branch portion and holds the slider.

[0128] The above-mentioned sprinkling device may be configured to include a plurality of sliders, the plurality of sliders being arranged at different positions in the axial direction of the hopper.

[0129] In the above-mentioned sprinkling device, two sliders adjacent to each other in the axial direction of the hopper may be arranged at different positions in the direction of rotation.

[0130] In the above-mentioned spraying device, a first pipeline is provided for guiding the object to be sprayed transported by the conveying unit to an ejector, and an outlet of the case opens downward at the other axial end side of the case of the conveying unit, and an inlet of a straight pipe extending downward is connected to the outlet of the case, and the outlet of the straight pipe and the inlet of the first pipeline may be arranged opposite each other above and below with a gap between them.

[0131] Furthermore, according to yet another embodiment of the present invention, there is provided a tire testing apparatus comprising: a rotating drum having a simulated road surface on its outer peripheral surface; a tire holding section that rotatably holds a test tire in contact with the simulated road surface; a drive section that rotates the rotating drum and the tire holding section; and the above-mentioned spraying device that sprays powder onto the outer peripheral surface of at least one of the rotating drum and the test tire, the powder making it difficult for rubber debris generated by wear of the test tire to adhere to the outer peripheral surface.

[0132] Furthermore, according to yet another embodiment of the present invention, there is provided a tire testing apparatus comprising a rotating drum having a simulated road surface on its outer periphery, a tire holding section which rotatably holds a test tire in contact with the simulated road surface, a torque generating section which generates a torque to be applied to the test tire, and a rotary drive section which has a motor which is an electric motor that drives and rotates the rotating drum, wherein the torque generating section comprises a rotatably supported case and a servo motor which is an electric motor coaxially attached to the case, and the rotary drive section drives and rotates the case of the torque generating section.

[0133] This configuration does not use a hydraulic system, so it is possible to prevent environmental pollution caused by hydraulic oil and reduce energy consumption compared to conventional hydraulic devices. Also, by introducing a torque generating unit (torque generating device), it is possible to share the two roles of rotation drive and torque generation between two motors, making it possible to use a small motor with low capacity, which allows for further energy and space savings.

[0134] In the tire testing apparatus described above, the simulated road surface may be formed by a plurality of simulated road surface units that are detachable from the outer periphery of the rotating drum.

[0135] According to this configuration, it becomes possible to manufacture the simulated road surface unit in a prefabricated manner, thereby improving production efficiency.

[0136] In the above tire testing apparatus, the simulated road surface unit may be configured to include a frame that is detachable from the outer periphery of the rotating drum, and a simulated road surface body that is detachable from the surface of the frame.

[0137] This configuration makes it easy to replace the simulated road surface body, which is a consumable item, and also makes it possible to increase the variety of the simulated road surface body at low cost.

[0138] In the tire testing apparatus described above, the simulated road surface may be formed from a material including aggregate and a binder that binds the aggregate.

[0139] In the tire testing apparatus, the aggregate includes ceramic pieces, The binder may include a curable resin.

[0140] In the above tire testing apparatus, the simulated road surface may be formed from the same material as (or a different material from) the surface of an actual road.

[0141] In the tire testing apparatus described above, the simulated road surface may have a plurality of driving lanes aligned in the axial direction of the rotating drum.

[0142] In the tire testing apparatus described above, the multiple travel lanes may be configured to be made of the same material (or different materials).

[0143] In the tire testing apparatus described above, the tire holding section may be configured to include a travel lane switching mechanism capable of switching the travel lane in which the rotating drum travels by moving the rotating drum in the axial direction.

[0144] The above tire testing apparatus may be configured to include a relay unit that relays the transmission of power from the rotational drive unit to the torque generating unit, a first connecting means that connects the rotational drive unit and the relay unit, and a second connecting means that connects the relay unit and the torque generating unit, wherein the second connecting means includes a wrapping transmission mechanism, and the wrapping transmission mechanism includes a passive pulley coaxially attached to a case of the torque generating unit.

[0145] In the above tire testing apparatus, the rotation drive unit may include a power coupling unit, and the power coupling unit may be configured to include an input shaft to which a motor is connected, and an output shaft having one end connected to the first connecting means and the other end connected to the shaft of the rotating drum.

[0146] In the above tire testing apparatus, the relay section may include a first gear connected to a first connecting means, and a second gear that meshes with the first gear and is connected to a second connecting means, and one of the first gear and the second gear is configured to be movable in a distance direction relative to the other gear so that the distance between the rotation axes of the first gear and the second gear can be changed. The one of the first connecting means and the second connecting means that is connected to one of the gears may be configured to include a drive shaft that has universal joints at both ends and is configured to have a variable length.

[0147] In the above tire testing apparatus, the torque generating unit may include a first shaft connected to the shaft of the servo motor, the case may be cylindrical with an opening at one end through which the first shaft passes, the servo motor and one end of the first shaft may be housed within the case, and the other end of the first shaft may be exposed to the outside of the case through the opening.

[0148] In the above tire testing apparatus, the tire holding unit may include a spindle unit that rotatably holds the test tire, and an alignment mechanism that can adjust the alignment of the test tire relative to the simulated road surface by changing the position or orientation of the spindle unit, and the spindle unit may include a wheel unit on which the tire is mounted, and a spindle at one end of which the wheel unit is coaxially attached and supported for rotation.

[0149] The tire testing apparatus may further comprise a third connecting means for connecting the first shaft of the torque generating portion and the spindle, the third connecting means including a constant velocity joint.

[0150] In the above tire testing apparatus, the tire holding section may be configured to include a spindle case that rotatably supports the spindle, a slip angle adjustment mechanism that can adjust the slip angle of the test tire by rotating the spindle case around an axis that is perpendicular to the contact surface where the test tire contacts the simulated road surface and passes through the center of the wheel section, a camber angle adjustment mechanism that can adjust the camber angle of the test tire by rotating the spindle case around an axis that passes through the contact surface and is perpendicular to the spindle, and a tire load adjustment mechanism that can adjust the vertical load of the test tire by moving the spindle case in a direction perpendicular to the contact surface.

[0151] The tire testing apparatus may further comprise the above-mentioned spraying device for spraying powder onto the outer periphery of at least one of the rotating drum and the test tire, the powder making it difficult for rubber chips generated by wear of the test tire to adhere to the outer periphery.

[0152] According to one embodiment of the present invention, it is possible to prevent rubber debris generated during tire testing from adhering to a tire testing device or a test tire, thereby preventing breakdowns in the tire testing device.

[0153] An object of one aspect of the present invention is to provide a tire testing apparatus capable of applying torque fluctuations to a test specimen.

[0154] According to one aspect of the present invention, there is provided a tire testing apparatus comprising: a rotating drum having a simulated road surface on its outer periphery; a rotary drive unit having a first electric motor that rotates and drives the rotating drum; a tire holding unit that rotatably holds a test tire in contact with the simulated road surface; a torque generating unit that generates torque that applies braking force or driving force to the test tire; and a relay unit that relays power transmission from the rotary drive unit to the torque generating unit, wherein the torque generating unit comprises a rotatably supported case and a second electric motor attached to the case, the rotary drive unit rotates and drives the case of the torque generating unit, and the relay unit comprises a shaft connected to the rotating drum and a gear box that connects the shaft and the case of the torque generating unit, and the shaft and the torque generating unit are arranged side by side.

[0155] In the tire testing apparatus described above, the gear box may include a first gear coupled to the shaft, and a second gear coupled to a case of the torque generating portion and meshing with the first gear.

[0156] In the tire testing apparatus described above, the test tire may be connected to a shaft of the second motor, and the rotating drum, relay unit and torque generating unit may be connected in an annular shape via the test tire to form a power circulation circuit.

[0157] According to another aspect of the present invention, there is provided a tire testing apparatus comprising: a rotating drum having a simulated road surface on its outer periphery; a rotary drive unit having a first electric motor that rotates and drives the rotating drum; a pair of tire holding units that rotatably hold a test tire in contact with the simulated road surface; a pair of torque generating units that generate torque to apply braking or driving force to each test tire; and a relay unit that relays the transmission of power from the rotary drive unit to each torque generating unit, wherein the torque generating units comprise a rotatably supported case and a second electric motor attached to the case, the rotary drive unit rotates and drives the case of the torque generating units, and the relay unit comprises a shaft connected to the rotating drum and a gear box that connects the shaft to the case of each torque generating unit, and the shaft and the pair of torque generating units are arranged side by side.

[0158] In the above tire testing apparatus, the gear box may include a first gear coupled to the shaft, and a pair of second gears coupled to cases of the respective torque generating portions and meshing with the first gear.

[0159] In the above tire testing apparatus, the test tire may be connected to the shaft of the corresponding second electric motor, and the rotating drum, relay unit and each torque generating unit may be connected in a ring shape via the corresponding test tire to form a power circulation circuit.

[0160] According to one aspect of the present invention, there is provided a tire testing apparatus capable of applying torque fluctuations to a test specimen.

Claims

1. A rotating drum having a simulated road surface on its outer periphery; A rotation drive unit that rotates the rotary drum; a tire holding portion that holds a test tire rotatably in a state where the test tire is in contact with the simulated road surface; a torque generating unit that generates a torque to apply a braking force or a driving force to the test tire; a relay unit that relays power transmission from the rotation drive unit to the torque generation unit; Equipped with The torque generating unit is a rotatably supported case; an electric motor attached to the case; A rotation drive unit rotates the case, The relay unit is a shaft coupled to the rotating drum; a gear box connecting the shaft and the case of the torque generating unit, The shaft and the torque generating portion are arranged substantially parallel to each other. Tire testing equipment.

2. The gear box, a first gear coupled to the shaft; a second gear coupled to a case of the torque generating unit and meshing with the first gear; Equipped with 2. A tire testing apparatus according to claim 1.

3. The test tire is connected to the shaft of the electric motor, The rotating drum, the relay unit, and the torque generating unit are connected in an annular shape via the test tire to form a power circulation circuit.

3. A tire testing apparatus according to claim 1 or 2.

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