Tire testing methods, tire testing equipment and distribution devices

Abstract

The purpose of this invention is to prevent tire testing device malfunctions by preventing rubber debris generated during tire testing from adhering to the tire testing device or the test tire. According to one embodiment of the invention, a tire testing method is provided, comprising: a contact step, in which a test tire contacts a simulated road surface disposed on the outer periphery of a rotating drum; a rotation step, in which the rotating drum and the test tire in contact with the simulated road surface are rotated; and a powder dispersing step, in which powder is dispersed on the outer peripheral surface of at least one of the rotating drum and the test tire, the powder reducing the adhesion of rubber debris generated by tire wear.

Description

Technical Field

[0001] The present invention relates to a tire testing method, a tire testing device, and a spreading device. Prior Art

[0002] For a tire wear test for evaluating the wear resistance of a tire, in addition to mounting the test tire on a real vehicle and traveling on an actual road surface under specific conditions to investigate the actual traveling test of the tire wear generated at this time, there is also a bench test (simulation test) as described in Japanese Patent Application Laid-Open No. 57-91440, in which the tire is in contact with the outer peripheral surface (simulated road surface) of a rotating drum, and the rotating drum and the tire are rotated to wear the tire. Summary of the Invention

[0003] In a tire testing device for performing such a simulation test, rubber chips generated by tire wear adhere to various parts of the tire testing device, which causes the tire testing device to malfunction.

[0004] In view of the above situation, an object of the present invention is to prevent rubber chips generated by a tire wear test from adhering to a tire testing device or a test tire, thereby preventing the tire testing device from malfunctioning.

[0005] According to an embodiment of the present invention, there is provided a tire testing method, including: a contact step of bringing a test tire into contact with 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 in contact with the simulated road surface; and a spreading step of spreading powder on at least one of the outer peripheral surfaces 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.

[0006] In the above tire testing method, the powder spreading step may also be configured to include: a conveying step of conveying the powder at a fixed speed; dispersing the powder to disperse the conveyed powder in a gas; and a blowing step of blowing the gas in which the powder is dispersed onto the outer peripheral surface.

[0007] In the above tire testing method, in the blowing step, the gas in which the powder is dispersed may also be configured to be blown from the front in the traveling direction toward the contact portion between the simulated road surface and the test tire.

[0008] In the above tire testing method, in the conveying step, it may also be configured to convey the powder at a fixed rate by rotating a screw of a conveying means at a fixed speed.

[0009] In the above tire testing method, the dispersion step may also include: a compressed gas supply step of supplying the gas compressed by the injector; attracting the powder by the negative pressure generated by the injector; and an ejection step of ejecting the powder dispersed in the gas from the injector.

[0010] In the above tire testing method, the dispersion step may also include: a guiding step of guiding through a pipeline to the position where the gas blown out from the injector blows; in the guiding step, the powder is uniformly dispersed in the gas.

[0011] In the above tire testing method, the blowing step may also be configured to blow out the gas in which the powder is dispersed from the bell mouth.

[0012] In the above tire testing method, the powder may also include talc.

[0013] Furthermore, according to another embodiment of the present invention, there is provided a spraying device including: a conveying unit that quantitatively conveys the object to be sprayed; and an injector that attracts the object to be sprayed conveyed by the conveying unit and ejects the gas that disperses the object to be sprayed.

[0014] According to this structure, there is provided a spraying device that can quantitatively (for example, continuously fix a certain amount per unit time) spray the object to be sprayed.

[0015] In the above spraying device, the conveying unit may also be configured to include: a screw; a cylindrical outer shell that houses the screw; and a driving unit that rotates the screw at a specific rotation speed.

[0016] In the above spraying device, the screw may also be configured as a substantially cylindrical member having a spiral groove formed on its outer peripheral surface.

[0017] In the above spraying device, it may also be configured to include: a funnel that stores the object to be sprayed; at one end side in the axial direction of the outer shell, the outer shell inlet opens upward; at the inlet, the discharge port of the funnel formed at the bottom of the funnel is connected.

[0018] In the above spraying device, it may also be configured to include: a stirrer that stirs the object to be sprayed in the funnel; the funnel has a cylindrical inner peripheral surface; the stirrer has: a slider that contacts and rotates with the inner peripheral surface of the funnel.

[0019] In the above-described scattering device, the agitator may also be configured to include: a rod disposed concentrically with the inner peripheral surface of the funnel and rotating about the axis of the inner peripheral surface; a branch portion extending from the side surface of the rod toward the inner peripheral surface of the funnel; and a slider holding portion mounted on the branch portion and holding the slider.

[0020] In the above-described scattering device, it may also be configured to include a plurality of sliders; the plurality of sliders are disposed at different positions in the axial direction of the funnel.

[0021] In the above-described scattering device, it may also be configured such that two sliders adjacent in the axial direction of the funnel are disposed at different positions in the rotational direction.

[0022] In the above-described scattering device, it may also be configured to include: a first pipe guiding the object to be scattered conveyed by the conveying unit to the injector; at the other end side in the axial direction of the outer shell of the conveying unit, the outlet of the outer shell opens downward; at the outlet of the outer shell, the inlet of a straight pipe extending downward is connected; the inlet of the straight pipe and the inlet of the first pipe are disposed opposite to each other vertically with a gap therebetween.

[0023] Furthermore, according to still another embodiment of the present invention, there is provided a tire testing device including: a rotating drum having a simulated road surface on its outer periphery; a tire holding unit holding a test tire rotatably in contact with the simulated road surface; a driving unit rotating the rotating drum and the tire holding unit; and the above-described scattering device scattering powder on at least a part of the outer peripheral surfaces of the rotating drum and the test tire, wherein the powder makes it difficult for rubber chips generated by the wear of the test tire to adhere.

[0024] Furthermore, according to still another embodiment of the present invention, there is provided a tire testing device including: a rotating drum having a simulated road surface on its outer periphery; a tire holding unit holding a test tire rotatably in contact with the simulated road surface; a torque generating unit generating a torque applied to the test tire; and a rotational driving unit including a motor that is an electric motor for rotationally driving the rotating drum, wherein the torque generating unit includes: a housing rotatably supported; and a servo motor that is an electric motor coaxially mounted on the housing; the rotational driving unit rotationally drives the housing of the torque generating unit.

[0025] According to this structure, since a hydraulic system is not used, environmental pollution caused by hydraulic oil can be prevented, and the energy consumption can be reduced compared to conventional devices using hydraulic pressure. Also, since by introducing the torque generating unit (torque generating device), the two roles of rotational driving and torque generation can be shared by two motors, low-capacity and small-sized motors can be used, and energy saving and space saving can be achieved.

[0026] In the above tire testing device, the simulated road surface can also be configured to be formed by a plurality of simulated road surface units that can be detachably attached to the outer periphery of the rotating drum.

[0027] According to this structure, the simulated road surface units can be prefabricated, which can improve production efficiency.

[0028] In the above tire testing device, the simulated road surface unit can also be configured to include: a frame that can be detachably attached to the outer periphery of the rotating drum; and a simulated road surface body that can be detachably attached to the surface of the aforementioned frame.

[0029] According to this structure, it is easy to replace the simulated road surface body as a consumable. Also, the variety of the simulated road surface body can be increased at low cost.

[0030] In the above tire testing device, the simulated road surface can also be configured to be formed by a material including aggregate and a binder that binds to the aggregate.

[0031] In the above tire testing device, it can also be configured such that the aggregate includes ceramic chips; and the binder includes a curable resin.

[0032] In the above tire testing device, the simulated road surface can also be configured to be formed by the same material (or different materials) as the actual road surface.

[0033] In the above tire testing device, the simulated road surface can also be configured to have: a plurality of travel channels arranged in parallel in the axial direction of the rotating drum.

[0034] In the above tire testing device, the plurality of travel channels can also be configured to be formed by the same material (or different materials).

[0035] In the above tire testing device, the tire holding part can also be configured to include: a travel channel switching mechanism that can switch the travel channel on which the rotating drum travels by moving the rotating drum in the axial direction.

[0036] In the above tire testing device, it may also be configured to include: a relay section that relays power transmission from the rotary drive section to the torque generating section; a first connection means that connects the rotary drive section and the relay section; and a second connection means that connects the relay section and the torque generating section, wherein the second connection means includes a winding transmission mechanism; the winding transmission mechanism includes: a driven pulley coaxially mounted on the housing of the torque generating section.

[0037] In the above tire testing device, the rotary drive section may also be configured to include a power coupling section; the power coupling section includes: an input shaft connected to a motor; and an output shaft connected to the first connection means at one end and to the shaft of the rotary drum at the other end.

[0038] In the above tire testing device, the relay section may also be configured to include: a first gear connected to the first connection means; and a second gear meshing with the first gear and connected to the second connection means; either the first gear or the second gear is configured to be movable in the distance direction from the other gear to change the distance between the rotation axes of the first gear and the second gear; among the first connection means and the second connection means, the one connected to a gear has universal joints at both ends and includes a drive shaft configured to be able to change its length.

[0039] In the above tire testing device, the torque generating section may also be configured to include: a first shaft connected to the shaft of the servo motor; the housing is a cylindrical shape with an opening for passing the first shaft formed at one end; the servo motor and the part on the one end side of the first shaft are housed in the housing; the part on the other end side of the first shaft protrudes from the opening to the outside of the housing.

[0040] In the above tire testing device, the tire holding section may also be configured to include: a mandrel section that holds the test tire rotatably; a calibration mechanism that can change the position or direction of the mandrel section to adjust the calibration of the test tire with respect to the simulated road surface, wherein the mandrel section includes: a wheel portion on which the tire is mounted; and a mandrel coaxially mounted with the wheel portion at one end and supported to be rotatable.

[0041] In the above tire testing device, it may also be configured to include: a third connection means that connects the first shaft of the torque generating section and the mandrel; the third connection means includes a constant velocity joint.

[0042] In the above tire testing device, the tire holding part may also be configured to include: a spindle housing that supports the spindle to be rotatable; a slip angle adjustment mechanism that can adjust the slip angle of the test tire by rotating the spindle housing around an axis passing through the center of the wheel part perpendicular to the contact surface where the test tire contacts the simulated road surface; a camber angle adjustment mechanism that can adjust the camber angle of the test tire by rotating the spindle housing around an axis perpendicular to the spindle through the contact surface; and a tire load adjustment mechanism that can adjust the vertical load of the test tire by moving the spindle housing in a direction perpendicular to the contact surface.

[0043] In the above tire testing device, it may also be configured to include: the above spreading device that spreads powder on the outer periphery of at least one of the rotating drum and the test tire, which makes it difficult for rubber chips generated by the wear of the test tire to adhere.

[0044] According to an embodiment of the present invention, preventing rubber chips generated by tire wear tests from adhering to the tire testing device or the test tire can prevent malfunctions of the tire testing device. Brief Explanation of Drawings

[0045] The first figure is a plan view of a tire testing device according to an embodiment of the present invention. The second figure is a front view of a tire testing device according to an embodiment of the present invention. The third figure is a right side view of a tire testing device according to an embodiment of the present invention. The fourth figure is a left side view of a tire testing device according to an embodiment of the present invention. The fifth figure is a block diagram showing the schematic structure of a control system. The sixth figure is an external view of a simulated road surface unit. The seventh figure is a cross-sectional view of a simulated road surface unit. The eighth figure is a longitudinal sectional view of a torque generating part. The ninth figure is a side view of a camber adjustment mechanism. The tenth figure is a schematic diagram of a two-dimensional contour of a tire tread. The eleventh figure shows a schematic structural diagram of a slip material spreading device. The twelfth figure is a plan view of a tire testing device according to a second embodiment of the present invention. The thirteenth figure is a front view of a tire testing device according to a second embodiment of the present invention. Embodiment

[0046] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding components are given the same or corresponding reference numerals, and redundant descriptions are omitted.

[0047] The first to fourth figures are, in order, a plan view, a front view, a right side view, and a left side view of a tire testing device 1 according to an embodiment of the present invention. In addition, for ease of explanation, a part of the tire testing device 1 is omitted in the second to fourth figures. Further, the fifth figure is a block diagram showing a schematic structure of a control system 1a of the tire testing device 1.

[0048] In the following description, as represented by coordinates in the first figure, the direction from left to right in the first figure is defined as the X-axis direction, the direction from bottom to top is defined as the Y-axis direction, and the direction perpendicular to the paper surface from the back side to the front side is defined as the Z-axis direction. The X-axis direction and the Y-axis direction are horizontal directions perpendicular to each other, and the Z-axis direction is a vertical direction.

[0049] The tire testing device 1 is a device for performing a tire bench test in which a test tire T is worn under conditions close to actual running test conditions by rotating a rotating drum 22 and the test tire T for a specific time (for example, 24 hours) in a state where the test tire T is in contact with a simulated road surface 23b provided on the outer periphery of the rotating drum 22. The tire testing device 1 of the present embodiment achieves high energy utilization efficiency by adopting an electric motor and a power circulation method in the drive system. Further, by a torque generating device described later, dedicated motors are provided for the two functions of rotational drive and torque application, and rotational control and torque control can be independently performed. Thereby, highly accurate torque control with high degrees of freedom can be performed, while the capacity of the electric motor can be reduced, the size of the testing device can be reduced, and power consumption can be reduced. Further, since an ultra-low inertia servo motor with excellent acceleration performance is used in the torque generating device, torque fluctuations having high-frequency components with rapid start and rapid braking can be accurately reproduced.

[0050] The tire test device 1 includes: a tire holding unit 10 that holds a test tire T; a road surface unit 20 that has a simulated road surface 23B in contact with the test tire T; a rotary drive unit 30 that rotates and drives a power circulation circuit; a torque generation unit 50 that generates braking force and driving force applied to the test tire T; and a relay unit 40 that relays the power transmission from the rotary drive unit 30 to the torque generation unit 50. Further, the tire test device 1 includes: a first connection means (drive shaft 62) that connects the rotary drive unit 30 and the relay unit 40; a second connection means (V-belt 66) that connects the relay unit 40 and the torque generation unit 50; and a third connection means (constant velocity joint 64) that connects the torque generation unit 50 and the tire holding unit 10 (spindle 152). The road surface unit 20, the rotary drive unit 30, the relay unit 40, the torque generation unit 50, and the spindle unit 15 of the tire holding unit 10 described later are annularly connected via the test tire T to form a power circulation circuit.

[0051] In addition, in the present embodiment, the rotary drum 22 is arranged in the Y-axis direction with respect to the rotation axis, but for example, it may also be arranged in the X-axis direction, the Z-axis direction, or an intermediate direction between these (for example, a direction at an angle of 45° to the X-axis and the Z-axis respectively) with respect to the rotation axis of the rotary drum 22. In this case, the directions or arrangements of the other parts of the tire test device 1 are also changed corresponding to the direction of the rotary drum 22.

[0052] Further, as shown in the fifth figure, the control system 1a of the tire test device 1 includes: a central control unit 70 that controls the overall operation of the test device; a measurement unit 80 that performs various measurements based on signals from various sensors provided in the tire test device 1; and an interface unit 90 that performs input / output with the outside.

[0053] As shown in the first to fourth figures, the road surface unit 20 includes: a rotary drum 22; a simulated road surface unit 23 provided on the outer peripheral portion of the rotary drum 22; and a bearing unit 24 that supports the shaft 22a of the rotary drum 22 rotatably. The bearing unit 24 includes: a rotary encoder 241 (fifth figure) that detects the rotation speed of the rotary drum 22. The simulated road surface unit 23 of the present embodiment is formed by a plurality of simulated road surface units 231 (sixth and seventh figures) arranged in parallel without gaps in the circumferential direction on the outer periphery of the rotary drum 22.

[0054] The sixth figure is a perspective view of the simulated road surface unit 231 installed on the outer periphery of the rotating drum 22. Also, the seventh figure is a cross-sectional view of the simulated road surface unit 231 cut along the cutting plane A-A' shown in the sixth figure. The simulated road surface unit 231 includes: a frame 231a; simulated road surface bodies 231b (231b1, 231b2) embedded in recesses 231ad formed on 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 frames 231a and are fixed to the frame 231a. The pressing plates 231c are fixed to the frame 231a with a plurality of flat head screws 231d. Also, through holes 231ah are formed at both ends in the width direction (the horizontal direction in the seventh figure) of the frame 231a, and the through holes 231ah pass through bolts for fixing the simulated road surface unit 231 to the rotating drum 22.

[0055] The simulated road surface 23b is formed by the surfaces of a plurality of simulated road surface bodies 231b arranged in parallel in the circumferential direction. The simulated road surface body 231b of the present embodiment is composed of two parts (the first part 231b1 on the left half and the second part 231b2 on the right half in the seventh figure) extending in the circumferential direction formed of different materials from each other. The first part 231b1 forms a first travel channel 23b1 described later, and the second part 231b2 forms a second travel channel 23b2.

[0056] In addition, the entire simulated road surface body 231b may be uniformly formed of a single material. Also, although the simulated road surface body 231b of the present embodiment is formed in a smooth cylindrical surface shape, 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 irregularities in the circumferential direction (or in both the circumferential direction and the width direction) on the surface.

[0057] Also, in the present embodiment, although the pre-formed simulated road surface body 231b is installed on the frame 231a by the pressing plates 231c, the simulated road surface body 231b may also be provided with through holes that pass through bolts for fixing the simulated road surface unit 231 to the rotating drum 22, and the simulated road surface body 231b may be directly fixed to the frame 231a with bolts. Also, for example, 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 a curable resin and hardening it.

[0058] The simulated road surface body 231b is a component formed by crushing (further grinding as needed) an aggregate such as silicon carbide or alumina with excellent abrasion resistance, and adding a binder (adhesive) containing a curable resin such as a polyurethane resin or an epoxy resin, and then shaping and hardening.

[0059] In this embodiment, the simulated road surface 23b is formed with two traveling channels (the first traveling channel 23b1 and the second traveling channel 23b2) separated in the axial direction (width direction) of the rotary drum 22. Also, in this embodiment, although two traveling channels are formed in the simulated road surface 23b, a single or three or more traveling channels may be formed. The two traveling channels 23b1 and 23b2 of the simulated road surface 23b are formed by changing the particle size or amount of the aggregate used. Looking in the traveling direction, the first traveling channel 23b1 on the right side is a simulated road surface simulating a smooth road surface such as an asphalt-paved road surface, and the second traveling channel 23b2 on the left side is a simulated road surface simulating a rough road surface such as a gravel road. By switching the traveling channels 23b1 and 23b2 of the simulated road surface 23b that the test tire T contacts, the road surface conditions can be changed. The switching of the traveling channels is performed by the traverse mechanism 11 (traveling channel switching mechanism) of the tire holding portion 10 described later.

[0060] The rotary drive unit 30 includes: a motor 32; and a power coupling portion 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 (Figure 5). The shaft 32b of the motor 32 is coupled to the input shaft 34a of the power coupling portion 34. One end 34b1 of the output shaft 34b of the power coupling portion 34 is coupled to the shaft 22a of the rotary stock 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 portion 34 forms a part of the power circulation circuit, and via the power coupling portion 34, the output shaft of the motor 32 is coupled to the power circulation circuit. That is, by the motor 32, the power circulation circuit is rotationally driven, and the rotational speed of the power circulation circuit is controlled.

[0061] The relay portion 40 includes: a gearbox 42; a drive pulley 44; a bearing portion 45 that rotatably supports the shaft of the drive pulley 44; a tension pulley 46 that applies a specific tension to the V-belt 66 wound around the drive pulley 44; and a bearing portion 47 that rotatably supports the shaft of the tension pulley 46.

[0062] The gearbox 42 includes: a first gear 42a that is coupled to the other end of the drive shaft 62; and a second gear 42b that meshes with the first gear 42a. The second gear 42b is coupled to the drive pulley 44. In this embodiment, since the number of teeth of the first gear 42a and the second gear 42b is the same, the gearbox 42 converts the rotation input from the drive shaft 62 into an equal-speed reverse rotation and transmits it to the drive pulley 44.

[0063] The first gear 42a and the second gear 42b can be exchanged for those with different numbers of teeth (diameters). For example, differences can also be given to the numbers of teeth of the first gear 42a and the second gear 42b, and the rotational speed can be increased or decreased by the gearbox 42. In order to change the numbers of teeth of the first gear 42a and the second gear 42b, the distance between the rotational axes of the first gear 42a and the second gear 42b can be changed. Specifically, the position of the rotational axis of the second gear 42b is fixed, and the position of the rotational axis of the first gear 42a can be moved laterally (in the direction of the distance from the second gear 42b, i.e., the X-axis direction). When changing the numbers of teeth of the respective gears, the position of the rotational axis of the first gear 42a is moved laterally to adjust the meshing of the second gear 42b. Universal joints 621 are provided at both ends, and the rotational drive unit 30 (specifically, the other end 34b2 of the output shaft 34b of the power coupling unit 34) is connected to the first gear 42a through the drive shaft 62 with variable length. Therefore, even if the first gear 42a moves laterally, no bending occurs in the drive shaft 62 or the first gear 42a, and the smooth rotation of the power circulation circuit is maintained.

[0064] The eighth figure is a longitudinal sectional view of the torque generating unit 50 (torque generating device). The torque generating unit 50 includes: an outer cylinder (outer shell) 51; a servo motor 52 disposed inside the outer cylinder 51; a speed reducer 53 and a shaft 54; three bearing parts 55, 55, 56 that support the outer cylinder 51 to be rotatable; a slip ring part 57 (slip ring 57a, brush 57b); a bearing part 58 that supports the slip ring 57a to be rotatable; and a driven pulley 59.

[0065] In this embodiment, the servo motor 52 uses an ultra-low inertia high-output type AC servo motor with an inertia moment of the rotating part of 0.01 kg·m2 or less and a rated output of 7 kW to 37 kW. As shown in the fifth figure, the servo motor 52 is connected to the central control unit 70 via a servo amplifier 52a.

[0066] The outer cylinder 51 has: a cylindrical motor housing part 512 and a speed reducer holding part 513 with a large diameter, and substantially cylindrical shaft parts 514 and 516 with a small diameter. At one end (the right end in the eighth figure) of the motor housing part 512, the shaft part 514 is coaxially (with the rotation axes coinciding) coupled. Also, at the other end (the left end in the eighth figure) of the motor housing part 512, the shaft part 516 is coaxially coupled via the speed reducer holding part 513. The shaft part 514 is supported by the bearing part 56 to be rotatable, and the shaft part 516 is supported by a pair of bearing parts 55 to be rotatable.

[0067] Between a pair of bearing portions 55, a driven pulley 59 coupled to a shaft portion 516 is disposed. The outer cylinder 51 is rotationally driven via the driven pulley 59 by a V-belt (first figure) wound between the drive pulleys 44 of the relay portion 40.

[0068] At both end portions on the inner surface of the shaft portion 516, bearings 517 are provided. A shaft 54 is inserted into the hollow portion of the shaft portion 516 and is supported by the shaft portion 516 via a pair of bearings 517 so as to be rotatable. The shaft 54 penetrates the shaft portion 516, and one end thereof projects into the speed reducer holding portion 513, and the other end projects outside the outer cylinder 51.

[0069] A servo motor 52 is housed in the hollow portion of the motor housing portion 512. The shaft 521 of the servo motor 52 is coaxially disposed with the motor housing portion 512, and the motor housing is fixed to the motor housing portion 512 by a plurality of rods 523. Further, a flange 522 of the servo motor 52 is coupled to a gear box 53a of a speed reducer 53 via a connection cylinder 524. Further, the gear box 53a of the speed reducer 53 is fixed to a flange 513a of the speed reducer holding portion 513.

[0070] The shaft 521 of the servo motor 52 is connected to an input shaft 531 of the speed reducer 53. Further, a shaft 54 is connected to an output shaft 532 of the speed reducer 53. The torque output from the servo motor 52 is amplified by the speed reducer 53 and transmitted to the shaft 54. The rotation of the shaft 54 is composed of 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.

[0071] A slip ring 57a is connected to a shaft portion 514 of the outer cylinder 51. Further, 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 passes through the hollow portion of the shaft portion 514 and is connected to the slip ring 57a. Further, the brush 57b is connected to a servo amplifier 52a (fifth figure). That is, the servo motor 52 and the servo amplifier 52a are connected via a slip ring portion 57.

[0072] Next, referring to FIGS. 1 to 3 and FIG. 9, the structure of the tire holding portion 10 will be described. FIG. 9 is a rear view (partial sectional view) of the tire holding portion 10. The tire holding portion 10 is a mechanism that causes the test tire T to contact the simulated road surface 23b in a specific orientation, applies a specific load, and holds it rotatably. The tire holding portion 10 includes: four substrates 101, 102, 103, and 104 stacked vertically; and a spindle portion 15 that holds the test tire T rotatably. Further, the tire holding portion 10 serves as a calibration mechanism for the test tire T and includes a traverse mechanism 11, a camber angle adjustment mechanism 12, a tire load adjustment mechanism 13, and a slip angle adjustment mechanism 14. The calibration mechanism is a mechanism that can adjust the calibration of the test tire T with respect to the simulated road surface 23b by changing the position or direction of the spindle portion 15.

[0073] The traverse mechanism 11 (travel path switching mechanism) is a mechanism that switches the travel paths 23b1 and 23b2 of the simulated road surface 23b that the test tire T contacts by moving the substrate 102 in the Y-axis direction relative to the substrate 101, thereby moving the position of the test tire T in the axial direction. The traverse mechanism 11 includes: a plurality of linear guides 111 that guide the substrate 102 in the axial direction (Y-axis direction) of the rotary drum 22 relative to the substrate 101; a servo motor 112 that drives the substrate 102; and a ball screw 113 (feed screw mechanism) that converts the rotational motion of the servo motor 112 into a linear motion in the Y-axis direction. In addition, the ball screw 113 includes a screw shaft 113a and a nut 113b.

[0074] Further, each linear guide 111 includes: a track 111a; and one or more carriers 111b that can travel on the track 111a via a rotating body (not shown). The track 111a of the linear guide 111 is installed on the upper surface of the substrate 101, and the carrier 111b is installed on the lower surface of the substrate 102. That is, the substrate 101 and the substrate 102 are connected via the linear guide 111 so as to be slidable in the Y-axis direction.

[0075] Also, a servo motor 112 with its axis in the Y-axis direction is installed on the substrate 101. The axis of the servo motor 112 is coupled to the screw shaft 113a of the ball screw 113, and the nut 113b is installed on the lower surface of the substrate 102. By driving the servo motor 112, the substrate 102 moves in the Y-axis direction relative to the substrate 101. Thereby, the position of the test tire T with respect to the rotary drum 22 moves in the Y-axis direction, and the travel paths 23b1 and 23b2 of the simulated road surface 23b that the test tire T contacts are switched.

[0076] As shown in the fifth figure, the servo motor 112 is connected to the central control unit 70 via the servo amplifier 112a. The traveling path switching operation performed by the servo motor 112 is controlled by the central control unit 70.

[0077] The ninth figure shows a rear view of the upper part of the tire holding unit 10. The camber angle adjusting mechanism 12 adjusts the camber angle of the test tire T by rotating the substrate 103 around the Z axis relative to the substrate 102. The camber angle adjusting mechanism 12 includes: a shaft 121 extending vertically; a bearing 122 that supports the shaft 121 rotatably; a curve guide 123 that guides the rotation of the substrate 103 centered on the shaft 121; a servo motor 124 that is mounted on the substrate 102 with its axis facing 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.

[0078] The shaft 121 is mounted on the substrate 103, and the bearing 122 is mounted on the substrate 102. A rotary encoder 122a (camber angle detection means) shown in the fifth figure is provided in the bearing 122 to detect the angular position of the shaft 121 (i.e., the camber angle). Also, the shaft 121 rotating drum 22 is disposed directly below the contact surface in contact with the test tire T. Specifically, the center line (rotation axis) of the shaft 121 is a straight line passing through the contact surface perpendicular to the spindle 152. The curve guide 123 includes: a track 123a extending in an arc concentric with the shaft 121; and one or more carriers 123b that can travel on the track 123a via a rotating body (not shown in the figure). The track 123a is mounted on the upper surface of the substrate 102, and the carrier 123b is mounted on the lower surface of the substrate 103. Also, the screw shaft 125a of the ball screw 125 is coupled to the shaft of the servo motor 124, and the nut 125b is mounted on the substrate 103 via a hinge 126 that can swing around the vertical axis. By driving the servo motor 124, the substrate 103 rotates around the shaft 121, and the camber angle of the test tire T changes.

[0079] As shown in the fifth figure, the servo motor 124 is connected to the central control unit 70 via the servo amplifier 124a. The adjustment of the camber angle operation performed by the servo motor 124 is controlled by the central control unit 70.

[0080] The tire load adjustment mechanism 13 is a mechanism that adjusts the vertical load (contact pressure) applied to the test tire T by moving the substrate 104 relative to the substrate 103 in the X-axis direction, causing the test tire T to move in the radial direction. The tire load adjustment mechanism 13 includes: a plurality of linear guides 131 that guide the substrate 104 in the radial direction (X-axis direction) of the rotary drum 22 relative to the substrate 103; a servo motor 132 that drives the substrate 104; and a ball screw 133 (feed screw mechanism) that converts the rotational motion of the servo motor 132 into a linear motion in the X-axis direction.

[0081] The linear guide 131 includes: a track 131a that extends in the X-axis direction; and a carrier 131b that travels on the track via a rotating body. The track 131a of the linear guide 131 is installed on the upper surface of the substrate 103, and the carrier 131b is installed on the lower surface of the substrate 104.

[0082] Also, a servo motor 132 with its axis in the X-axis direction is installed on the substrate 103. The axis of the servo motor 132 is coupled to the screw shaft 133a of the ball screw 133, and a nut 133b is installed on the substrate 104. By driving the servo motor 132, together with the nut 133b, the substrate 104 moves relative to the substrate 103 in the X-axis direction. Thereby, the axial distance between the rotary drum 22 and the test tire T changes, and the load on the test tire T changes.

[0083] As shown in the fifth figure, 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 performed by the servo motor 132 is controlled by the central control unit 70.

[0084] The slip angle adjustment mechanism 14 is a mechanism that adjusts the slip angle of the test tire T by rotating the spindle portion 15 of the substrate 104 around the X-axis, causing the rotation axis of the test tire T to tilt around the X-axis relative to the rotation axis of the rotary drum 22.

[0085] The slip angle adjustment mechanism 14 includes: a shaft 141, one end of which is fixed to the spindle housing 154 (bearing portion) of the spindle portion 15 and extends in the Y-axis direction; a bearing portion 142 that supports the shaft 141 to be rotatable around the X-axis (i.e., around the axis perpendicular to the contact surface); a servo motor 143; and a ball screw 144 (feed screw mechanism). The bearing portion 142 includes a rotary encoder 142a (Figure 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 configured to be perpendicular to the rotation axis of the wheel portion 156. The servo motor 143 is axially oriented in the approximate Z-axis direction and is mounted on the substrate 104 via a hinge 143b that can swing around the Y-axis. The shaft of the servo motor 143 is coupled to the screw shaft 144a of the ball screw 144. Further, the nut 144b of the ball screw 144 is mounted on one end portion of the spindle housing 154 in the X-axis direction (at a position away from the center of the shaft 141 in the X-axis direction) via a hinge 146 that can swing around the Y-axis.

[0086] By driving the servo motor 143, the nut 144b of the ball screw 144 moves up and down, and the spindle housing 154 rotates together with the shaft 141. Thereby, the slip angle of the test tire T held in the spindle portion 15 changes.

[0087] As shown in Figure 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 is controlled by the central control unit 70.

[0088] The spindle portion 15 includes: a spindle 152; a spindle housing 154 (bearing portion) that supports the spindle 152 to be rotatable; and a wheel portion 156 that is coaxially mounted on one end of the spindle 152. The test tire T is mounted on the wheel portion 156. The spindle 152 includes: a torque sensor 152a that detects the torque applied to the test tire T; and a three-component force sensor 152b that detects the three-component force applied to the test tire T (i.e., the force in the X-axis direction [Radial Force; load], the force in the Y-axis direction [Lateral Force; lateral force], and the force in the Z-axis direction [Tractive Force; traction force]). Further, the spindle housing 154 includes a rotary encoder 154b (Figure 5) that detects the rotation speed of the spindle (i.e., the test tire T). In either the torque sensor 152a or the three-component force sensor 152b, a piezoelectric element is used, so the spindle 152 and the spindle housing 154 have high rigidity, thereby enabling highly accurate measurement. Further, the wheel portion 156 includes an air pressure sensor (Figure 5) 156a that detects the air pressure of the test tire T.

[0089] The tire holding part 10 is provided with a tire temperature adjustment system 18 (only the air supply duct 182a is shown in the second figure), which blows cold air or warm air to the test tire T to adjust the temperature of the test tire T. The temperature of the test tire T (especially the tread temperature) during the test (when traveling) affects the test result (wear amount). Therefore, during the test, it is preferable to keep the tread temperature of the test tire T within a specific temperature range (for example, 35 ± 5°C). Also, even when measuring the wear amount of the test tire T described later, the temperature of the test tire T during measurement needs to be adjusted to a specific reference temperature (for example, 25°C). Therefore, the tire temperature adjustment system 18 is used to adjust the temperature of the test tire T to the set temperature during the test and when measuring the wear amount.

[0090] The tire temperature adjustment system 18 (shown in the fifth figure) is provided with 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 tread temperature of the test tire T and is arranged facing the tread. The control unit 181 controls the operation of the spot air conditioner 182 based on the measurement result of the temperature sensor 183 to blow cold air, warm air, or room temperature air to the tread of the test tire T, etc., to eliminate the deviation from the set temperature. The set temperature of the test tire T can be set to different values during the test (when traveling) and when measuring the wear amount. Also, different set temperatures can be set corresponding to the type of the test tire T. Further, the tire temperature adjustment system 18 is also provided with a temperature sensor for measuring the room temperature, and it can also be configured to control the operation of the spot air conditioner 182 based on the room temperature and the temperature of the test tire T.

[0091] In addition, although the tire temperature adjustment system 18 of the present embodiment is configured to adjust the temperature of the test tire T by blowing warm air or cold air to the test tire T using the spot air conditioner 182, the tire temperature adjustment system is not limited to this. For example, an outer cover (constant temperature chamber) surrounding the entire test tire T can also be provided, and the temperature of the test tire T can be adjusted by adjusting the air temperature inside the outer cover.

[0092] Also, the set temperature during the test can be set in accordance with the climate of the tire ground. Also, the wear of the tire is promoted by temperature rise. Therefore, by using the tire temperature adjustment system 18 to adjust the temperature of the test tire T during the test to be higher than the tire temperature during normal traveling, an accelerated degradation test can also be performed.

[0093] Further, the tire holding unit 10 includes a two-dimensional laser displacement sensor 17 (hereinafter abbreviated as "displacement sensor 17"), which is used to measure the wear amount of the tread of the test tire T. The displacement sensor 17 uses a laser beam (laser light curtain) expanded into a strip shape by a cylindrical lens to non-contact measure the two-dimensional profile of the tread of the test tire T (the cross-sectional shape cut by a plane including the tire rotation axis).

[0094] As shown in the fifth figure, the displacement sensor 17 is connected to the measurement unit 80 and operates together with the measurement unit 80 as a wear measurement unit. The measurement unit 80 controls the operation of the displacement sensor 17 and calculates the wear amount of the test tire T based on the two-dimensional profile obtained by the displacement sensor 17.

[0095] The measurement of the two-dimensional profile is performed by the wear measurement unit with the test tire in a prohibited state, before and after (and during) the test of the tire. Based on the two-dimensional profiles measured before and after (and during) the test, the wear amount of the test tire T caused by the test is calculated. Further, as described above, since the measured value of the tire wear amount is affected by the tire temperature, it is preferable to perform the measurement after the test is completed (or stopped) after the entire tire reaches a specific reference temperature by natural heat dissipation or forced cooling by the tire temperature control system 18.

[0096] The tenth figure is a schematic diagram of the two-dimensional profile of the tread of the test tire T obtained by measuring the two-dimensional profile with the wear measurement unit. In the tenth figure, the horizontal axis (Y) represents the position in the width direction of the test tire T, and the vertical axis (H) represents the position in the groove height direction (radial direction of the test tire T) of the test tire T. In the test tire T, four grooves G1, G2, G3, and G4 extending in the circumferential direction are formed. By image analysis of the two-dimensional profile, the Y-shaped concave portions in the two-dimensional profile correspond to the respective grooves G1 to G4.

[0097] Further, in a specific range on both sides in the width direction (Y-axis direction) of each of the grooves G1 to G4, adjacent regions L1 and R1, L2 and R2, L3 and R3, and L4 and R4 are respectively set. Hereinafter, the nth groove is represented by the symbol Gn, and the adjacent regions of the groove Gn are represented by the symbols Ln and Rn. Further, the adjacent region on the negative side of the horizontal axis of the groove Gn (the left side in the tenth figure) is defined as the adjacent region Ln, and the adjacent region on the positive side of the horizontal axis of the groove Gn (the right side in the tenth figure) is defined as the adjacent region Rn. The adjacent region Ln (Rn) is set to be, for example, a region up to a distance of half the width of the groove Gn from the left end (right end) of the groove Gn.

[0098] The depth Dn of the groove Gn is calculated as the difference between the average value of the height H in the adjacent regions Ln and Rn, for example, and the average value of the height H of the groove Gn. Also, the wear amount Wn of each groove Gn before and after the test is calculated as the difference in the depth Dn of the groove Gn before and after the test. Also, the average wear amount of the test tire T is calculated as the average value of the wear amounts W1 to W4.

[0099] Also, in addition to (or instead of) the depth Dn of the groove described above, the minimum groove depth Dnmin can also be calculated. The minimum groove depth Dnmin of the groove Gn is calculated as the difference between the average value of the minimum value of the height H in the adjacent region Ln and the average value of the minimum value of the height H in the adjacent region Rn, and the maximum value of the height H in the groove Gn. In this case, the minimum groove depth Dnmin can also be used instead of the depth Dn of the groove to calculate the wear amount Wn or the average wear amount W.

[0100] The calculation method of the wear amount Wn or the average wear amount W is not limited to the examples shown above, and other methods can also be used for calculation. For example, in the above example, although the height H of both the adjacent regions Ln and Rn is used to calculate the depth Dn or the minimum groove depth Dnmin of the groove Gn, the height H of either the adjacent region Ln or Rn (for example, the one closer to the center in the width direction of the test tire T) can also be used to calculate the depth Dn of the groove Gn, etc. Also, the least squares method or the like can be used to obtain approximate curves (for example, two-dimensional curves) of the two-dimensional contours for the portions of the grooves G1 to G4 and the portions other than the grooves G1 to G4, respectively, and the average distance difference between the two approximate curves before and after the test can be used as the average wear amount W for calculation.

[0101] Also, the wear measurement unit calculates and indicates the wear amount WL per unit travel distance (for example, 1 km) or the wear amount WT per unit travel time (for example, 1 hour) together with the wear amount Wn or the average wear amount W of each groove Gn.

[0102] The tire holding unit 10 includes: a lubricant dispersing device 16 (powder dispersing device) that disperses a lubricant (dispersed body) on the tread of the test tire T and the simulated road surface 23b of the rotating drum 22. The lubricant dispersing device 16 disperses a mixture of the lubricant dispersed in the air from the front in the traveling direction of the contact portion between the test tire T and the simulated road surface 23b (above in the first figure). Thereby, the rubber powder generated by the wear of the test tire T is prevented from causing malfunction or failure due to adhering to each part of the tire test device 1. Also, by the dispersion of the lubricant, the influence of the adhesion of the rubber powder to the test tire T or the simulated road surface 23b, etc. on the test results is reduced, and the test accuracy is improved.

[0103] The lubricant used is an incombustible powder such as talc (hydrous magnesium silicate). Thereby, dust explosion can be prevented, and safety measures for dust explosion such as explosion-proof equipment are not required, and the initial cost and maintenance cost can be significantly reduced.

[0104] The eleventh figure shows a schematic structural diagram of the lubricant spraying device 16. The lubricant spraying device 16 includes: a funnel 161 (storage part) for storing the lubricant; a stirrer for stirring inside the funnel 161; a driving part 163 for rotationally driving the stirrer 162; a metering conveyance part 164 for metering and conveying the lubricant; an injector 166 for sucking the lubricant and mixing it with air for ejection; a pipeline 165 for guiding the lubricant from the metering conveyance part 164 to the injector 166; a pipeline 167 for guiding the air in which the lubricant is dispersed from the injector 166 to the spraying position; and a bell mouth 168 installed at the front end of the pipeline 167.

[0105] The stirrer 162 includes: a rod 162a extending vertically; three pairs of branch parts 162b extending perpendicular to the radial direction from the side surface of the rod 162a toward the inner peripheral surface of the funnel 161; three slider holding parts 162c (slider holding parts) respectively installed at the front end parts of each pair of the branch parts 162b; and three sliders 162d (sliders) held by the slider holding parts 162c. The rod 162a is arranged concentrically with the cylindrical inner peripheral surface of the funnel 161, and one end thereof is connected to the driving part 163. Each slider 162d is arranged such that the front end contacts the inner peripheral surface of the funnel 161, scrapes off the lubricant adhering to the inner peripheral surface of the funnel 161, and rotates along the inner peripheral surface of the funnel 161. In this embodiment, a brush formed of a resin having conductivity (or anti-static property) is used as the slider 162d. During the operation of the tire testing device 1, the lubricant in the funnel 161 is always stirred by the stirrer 162. Thereby, it is possible to prevent the change or interruption of the lubricant supply amount due to the condensation and blockage of the lubricant in the funnel 161. The lubricant easily becomes the starting point of condensation adhering to the inner peripheral surface of the funnel 161, so by rubbing the front end of the slider 162d against the inner peripheral surface of the funnel 161, the blockage of the lubricant can be effectively prevented, and the stable supply of the lubricant can be carried out.

[0106] In addition, in the present embodiment, although a brush is used as the slider 162d, components other than a brush (such as a sponge or a sheet having rubber elasticity) may also be used as the slider 162d. Due to the elasticity of the slider 162d, the slider 162d is pressed against the inner peripheral surface of the funnel 161 with an appropriate force to scrape off the lubricant fixed to the inner peripheral surface of the funnel 161. Also, when the slider 162d does not have appropriate elasticity, elasticity may be provided in the slider holding portion 162c or the slider 162d. For example, a flat spring is used in the branch portion 162b, and the slider 162d can be pressed against the inner peripheral surface of the funnel 161 by the elastic force of the flat spring. Also, by using a slider 162d made of resin or rubber, damage or wear of the inner peripheral surface of the funnel 161 caused by the sliding of the slider 162d is prevented.

[0107] Also, by using a slider 162d formed of a material having conductivity (such as a synthetic resin blended with carbon black), the accumulation of the lubricant on the surface of the slider 162d due to static electricity is prevented.

[0108] The drive unit 163 includes: a motor 163m; a driver 163md (Figure 5) that supplies drive current to the motor 163m; and a speed reducer 163g that reduces the rotational speed of the output of the motor 163m.

[0109] The axes of the funnel 161 and the stirrer 162 are in the vertical direction in the present embodiment, but they may also be in the up-and-down direction (that is, the axes may be inclined relative to the vertical).

[0110] The metering and conveying unit 164 includes: a cylindrical outer shell 164a having a cylindrical hollow portion; a substantially cylindrical screw 164b concentrically accommodated in the hollow portion of the outer shell 164a; and a drive unit 164c that rotationally drives the screw 164b. The drive unit 164c includes: a servo motor 164cm; and a servo amplifier 164cma that supplies drive current to the servo motor 164cm. Other types of motors capable of controlling the rotational speed may be used instead of the servo motor 164cm.

[0111] The screw 164b has: a substantially cylindrical body portion 164b1 formed with a spiral groove on the outer periphery; and a shaft portion 164b2 extending in the axial direction from both axial ends of the body portion 164b1 and being thinner than the body portion 164b1. Also, bearing holes 164a1 that are fitted with the shaft portion 164b2 for rotation are respectively formed at both axial ends of the outer shell 164a in the axial direction. One of the shaft portions 164b2 is connected to the shaft of the drive unit 164c.

[0112] Openings are provided at both axial ends of the housing 164a. One opening (i.e., the inlet 164a2) is formed on the upper surface at one end side of the housing 164a. Also, the other opening (i.e., the outlet 164a3) is formed on the lower surface at the other end side of the housing 164a. The inlet 164a2 is connected to the discharge port of the funnel 161, and the outlet 164a3 is connected to a straight pipe 164d extending vertically.

[0113] On the outer circumference of the screw 164b, a spiral groove is formed. The spiral groove is formed in a semicircular shape. In this embodiment, although the pitch of the spiral groove is fixed, it can also be an unequal pitch. Also, a plurality of spiral grooves (a plurality of spiral structures) can be formed on the screw 164b. The outer diameter of the main body portion 164b1 of the screw 164b is slightly smaller than the inner diameter of the hollow portion of the housing 164a. In addition, when the gap between the outer peripheral surface of the screw 164b and the inner peripheral surface of the housing is narrow, the lubricant blocks in the gap and the frictional resistance increases. On the contrary, if the gap is wide, the conveying efficiency decreases.

[0114] By the rotation of the screw 164b, the lubricant moves from the inlet 164a2 to the outlet 164a3 in the hollow portion of the housing 164a and is discharged from the straight pipe 164d. Since the amount of lubricant conveyed per rotation of the screw 164b is fixed, by rotating the screw 164b at a constant speed, the lubricant can be continuously supplied at a fixed speed. Also, by changing the rotation speed of the screw 164b, the supply speed of the lubricant can be adjusted.

[0115] The injector 166 operates using the compressed air supplied from the pipe 166a as a driving source. By injecting the compressed air at high speed from the built-in nozzle toward the discharge side, the suction port connected to the pipe 165 is made negative pressure, the lubricant is sucked from the suction port, and at the same time, the lubricant is ejected from the discharge port connected to the pipe 167 along with the air.

[0116] The inlet of the pipe 165 and the outlet of the straight pipe 164d of the metering conveyor 164 are arranged opposite to each other vertically with a gap G therebetween. Due to the negative pressure generated by the injector 166, air flows into the pipe 165 from the gap G. The lubricant falling from the outlet of the straight pipe 164d is guided to the pipe 165 by the air flowing in from the gap G.

[0117] In addition, the front end of the pipeline 167 (bell mouth 168) is disposed directly above the contact portion between the test tire T and the simulated road surface 23b. The air containing the lubricant ejected from the injector 166 passes through the pipeline 167 and is ejected from the bell mouth 168 toward the contact portion. Also, as shown in the eleventh figure, the test tire T and the rotary drum 22 are rotationally driven in the direction of moving downward at the contact portion. That is to say, the lubricant is ejected from the front in the traveling direction toward the contact portion.

[0118] By using the lubricant scattering device 16 described above, the lubricant is scattered in front of the contact portion between the test tire T and the simulated road surface 23b, preventing rubber chips generated by the wear of the test tire T from adhering to the test tire T or the tire test device 1, and preventing the test accuracy from being reduced or the tire test device 1 from malfunctioning due to the adhesion of the rubber chips.

[0119] As shown in the fifth figure, the motor 163m of the drive unit 163 and the servo motor 164cm of the metering conveyance unit 164 of the lubricant scattering device 16 are connected to the central control unit 70. The operation of the lubricant scattering device 16 is controlled by the central control unit 70.

[0120] As shown in the fifth figure, the interface portion 90 of the control system 1a includes one or more user interfaces for input / output between users, various network interfaces for connecting networks such as a Local Area Network (LAN), and various communication interfaces such as a Universal Serial Bus (USB) or a General Purpose Interface Bus (GPIB) for connecting external machines. In addition, the user interface includes one or more various input / output devices such as various operation switches, display devices such as a display, a liquid crystal display (LCD), various pointing devices such as a mouse or a touch pad, a touch screen, a camera, a printer, a scanner, a buzzer, a speaker, a microphone, and a memory card reader.

[0121] The measurement unit 80 is connected to a displacement sensor 17, rotary encoders 122a, 142a, 154b, and 241, a torque sensor 152a, a three-component force sensor 152b, a pneumatic pressure sensor 156a, and a temperature sensor 183. The measurement unit 80 measures the torque, load (Radial Force), tractive force, and (Lateral Force) applied to the test tire T, the rotational speed of the test tire T, the camber angle, the slip angle, the temperature of the tread, the air pressure, the rotational speed of the rotary drum 22, and the road surface speed (circumferential speed of the rotary drum 22) based on the signals from the respective sensors, and transmits these measured values to the central control unit 70. In addition, the road surface speed is calculated from the measured value of the rotational speed of the rotary drum 22 of the rotary encoder 241.

[0122] The central control unit 70, in response to the setting, displays the measured values obtained from the measurement unit 80 on the display device, and at the same time stores them in the non-volatile memory 71 together with the measurement time.

[0123] In the central control unit 70, servo motors 52, 112, 124, 132, 143, and 164cm are respectively connected via servo amplifiers 52a, 112a, 124a, 132a, 143a, and 164cma. Also, in the central control unit 70, a motor 32 and a motor 163m are respectively connected via a converter circuit 32a and a driver 163md. Furthermore, in the central control unit 70, a fixed-point air conditioner 182 and a temperature sensor 183 are connected via the control unit 181 of the tire temperature adjustment system 18.

[0124] In the test using the tire test device 1 of the present embodiment, regarding the tire (hereinafter referred to as "reference tire") having a design that becomes a preset reference, when it is mounted on a real vehicle and travels, an actual driving test for investigating the tire wear state is performed. Even when a bench test is performed using the tire test device 1, in order to reproduce the same wear state as the actual driving test, the test conditions are adjusted, and various tires are tested under the adjusted test conditions (referred to as "adjusted test conditions"). In addition, the reference tire is selected from tires that are relatively close in design to the tires to be tested. For example, reference tires are respectively set for passenger car tires and bus / truck tires.

[0125] According to the embodiment of the present invention described above, since an electric motor is used instead of a hydraulic device, the power consumption can be significantly reduced compared to conventional test devices.

[0126] Moreover, since the power consumption is low, the tire test apparatus 1 can be stably operated even when power supply is restricted due to a large-scale disaster or the like.

[0127] In addition, since a hydraulic device is not used, there is no problem of environmental pollution caused by hydraulic oil.

[0128] Moreover, since the quality of a rubber tire deteriorates when it comes into contact with hydraulic oil, it is difficult to conduct a correct test in a test environment contaminated with hydraulic oil. If the tire test apparatus 1 of the present embodiment is used, since the test tire T is not contaminated with hydraulic oil, a more correct test can be conducted.

[0129] In addition, in the present embodiment, by using an ultra-low inertia high-output type AC servo motor having an inertia moment of the rotating part of 0.01 kg·m2 or less and a rated output of 22 kW (7 kW to 37 kW) in the torque generating unit 50 (torque generating device), rapid torque fluctuations can be generated, and complex waveform torque changes can be correctly reproduced.

[0130] In addition, in a conventional power circulation system, since torque is first applied to the power circulation circuit and rotational driving is started in a state where torque is applied, torque cannot be changed during the test, and only a fixed torque can be applied. In the tire test apparatus 1 of the present embodiment, by adopting a structure in which a torque generating device equipped with an ultra-low inertia high-output type AC servo motor is combined in the power circulation circuit, complex torque fluctuations can be applied to the specimen at high speed (high frequency) during high-speed travel, and rapid acceleration or deceleration during high-speed travel, and tests under severe and complex conditions such as ABS braking tests can be correctly simulated.

[0131] In a structure using a conventional single driving motor, since the driving motor requires high-speed and high-torque rotational driving, a large-capacity motor of 600 kW or more is required even for testing passenger car tires. However, since by adopting the torque generating device of the present embodiment, the roles of the respective motors are divided into low-speed and high-torque driving and high-speed and low-torque driving, the capacity of the servo motor 52 of the torque generating unit 50 is sufficient at 22 kW, and since the capacity of the rotational driving unit 30 is also sufficient at 37 kW, even when totaled, a capacity of 60 kW is sufficient, and the required power consumption can be reduced by about 1 / 10. In addition, for a test apparatus suitable for testing truck and bus tires, the power consumption is reduced by about 1 / 13. In addition, in the case of using a hydraulic motor, although power is also used for temperature management of the hydraulic oil during non-operation, the electric motor hardly consumes power during stoppage, so the substantial power consumption can be reduced to about 1 / 15.

[0132] Moreover, since a low-capacity motor is used, the manufacturing cost can be reduced and the device can be miniaturized.

[0133] Moreover, in the tire testing device 1 of the present embodiment, since a new composite material is used to form the simulated road surface 23b, the durability of the simulated road surface 23b can be improved and the maintenance cost can be reduced. Further, if the simulated road surface 23b of the present embodiment is used, by changing the aggregate or the adhesive, tests simulating various road surfaces can be correctly performed.

[0134] (Second Embodiment) Next, a second embodiment of the present invention will be described. FIGS. 12 and 13 are a plan view and a front view, respectively, of a tire testing device 1000 according to the second embodiment of the present invention. Also, for ease of explanation, in each figure, a part of the tire testing device 1000 is shown in section. Also, for components that are common or corresponding to those of the first embodiment, the same or corresponding reference numerals are given, and repeated explanations are omitted.

[0135] The tire testing device 1000 of the present embodiment is configured such that a single testing device can perform tests on passenger car tires and bus / truck tires.

[0136] The tire testing device 1000 is configured to include: two systems of power circulation circuits (power circulation circuit A, power circulation circuit B), sharing a part of the relay unit 1040 (gearbox 1042, shaft 1049) and the road surface unit 1020 (rotating drum 1022), and capable of simultaneously performing tests on two test tires T1 and T2.

[0137] Moreover, in the present embodiment, the rotary drive unit 1030 is provided on the frame 1020F of the road surface unit 1020, and is configured such that the power of the motor 1032 is transmitted to each of the power circulation circuits A and B via the drive pulley 1034 coupled to the shaft of the motor 1032, the V-belt 1068, and the rotating drum 1022.

[0138] In the relay sections 1040A and 1040B, two sets of drive pulleys 1044A and 1044B and driven pulleys 1048A and 1048B are respectively provided. One set has a reduction ratio suitable for car tire testing, and the other set has a reduction ratio suitable for bus and truck tire testing. When testing car tires, the V-belts 1066A and 1066B are wound around the pulley pairs for car tires. When testing bus and truck tires, the V-belts 1066A and 1066B are wound around the pulley pairs for bus and truck tires. By simply replacing the V-belts 1066A and 1066B, the reduction ratio suitable for various tires can be changed.

[0139] The relay section 1040 includes a first gear 1042a and two second gears 1042b. Through holes are respectively provided at the centers of the first gear 1042a and the second gears 1042b. Through these through holes, shafts 1041A and 1041B pass through without contact. Driven pulleys 1048A and 1048B are installed at one ends of the shafts 1041A and 1041B. The other ends of the shafts 1041A and 1041B are respectively connected to the shafts 1051A and 1051B of the torque generating sections 1050A and 1050B. In addition, each second gear 1042b is coupled to the outer cylinder 1051 of the torque generating sections 1050A and 1050B.

[0140] The above is the description of an embodiment of the present invention. The embodiments of the present invention are not limited to the above description and can be variously modified. For example, by appropriately combining the structures of the embodiments explicitly exemplified in this specification and / or the descriptions in this specification with the structures of the embodiments that are obvious to those skilled in the art, such combinations are also included in the embodiments of this application.

[0141] In the above embodiment, although the position of the rotation axis of the first gear 42a of the relay section 40 is configured to be laterally movable, the position of the rotation axis of the second gear 42b can also be configured to be laterally movable. In this case, the second gear 42b and the drive pulley 44 are connected by, for example, a drive shaft 62 having a universal joint or the like to allow the movement of the second gear 42b.

[0142] In the above embodiment, although a V-belt is used as the second connecting means, a flat belt, a toothed belt, or other belts can also be used as the second connecting means. Also, as the second connecting means, a chain, a wire, or other winding connectors can be used. Further, in the above first embodiment, although the relay section 40 and the torque generating section 50 are connected by a single V-belt, they can also be connected by a plurality of second connecting means in a parallel or series connection. Also, in the case where a plurality of second connecting means are connected in series, different types of second connecting means can also be combined and used.

[0143] 1. 1000: Tire testing device 1a: Control system 10: Tire holding part 11: Transverse movement mechanism 12: Camber angle adjustment mechanism 13: Tire load adjustment mechanism 14: Slip angle adjustment mechanism 15: Spindle part 16: Slippery material spraying device 17: Displacement sensor 18: Tire temperature regulation system 20. 1020: Road surface part 22. 1022: Rotating drum 22a, 32b, 54, 121, 141, 521, 1041A, 1041B, 1049, 1051A, 1051B: Shaft 23: Simulated road surface part 23b: Simulated road surface 23b1: First travel channel 23b2: Second travel channel 24, 45, 47, 55, 56, 58, 142: Bearing part 30. 1030: Rotating drive part 32, 163m, 1032: Motor 32a: Converter circuit 34: Power coupling part 34a, 531: Input shaft 34b, 532: Output shaft 34b1, 34b2: End 40, 1040, 1040A, 1040B: Relay part 42, 53a, 1042: Gearbox 42a, 1042a: First gear 42b, 1042b: Second gear 44, 1034, 1044A, 1044B: Driving pulley 46: Tension pulley 50, 1050A, 1050B: Torque generating part 51, 1051: Outer cylinder 52, 112, 124, 132, 143, 164cm: Servo motor 52a, 112a, 124a, 132a, 143a, 164cma: Servo amplifier 53, 163g: Reducer 57: Slip ring section 57a: Slip ring 57b: Brush 58a: Fixed frame 59, 1048A, 1048B: Driven pulley 62: Drive shaft 64: Constant velocity joint 66, 1066A, 1066B, 1068: V-belt 70: Central control unit 80: Measuring unit 90: Interface section 101, 102, 103, 104: Substrate 111, 131: Linear guide 111a, 123a, 131a: Rail 111b, 123b, 131b: Carrier 113, 125, 133, 144: Ball screw 113a, 125a, 133a, 144a: Screw shaft 113b, 133b, 144b: Nut 122, 517: Bearing 122a, 142a, 154b, 241: Rotary encoder 123: Curved guide 126, 143b, 146: Hinge 152: Mandrel 152a: Torque sensor 152b: Three-component force sensor 154: Mandrel housing 156: Wheel part 156a: Pneumatic sensor 161: Hopper 162: Stirrer 162a, 523: Rod 162b: Branch part 162c: Slide piece holding part 162d: Slide piece 163, 164c: Driving part 163md: Driver 164: Quantitative conveying part 164a: Outer shell 164a1: Bearing hole 164a2: Inlet 164a3: Outlet 164b: Screw 164b1: Body part 164b2, 514, 516: Shaft part 164d: Straight pipe 165, 167: Pipeline 166: Injector 168: Bell mouth 181: Control part 182: Fixed-point air conditioner 182a: Air supply duct 183: Temperature sensor 231: Simulated road surface unit 231a, 1020F: Frame 231ad: Recess 231ah: Through hole 231b: Simulated road surface body 231b1: First part 231b2: Second part 231c: Pressure plate 231d: Flat head screw 241: Rotary encoder 512: Motor housing part 513: Reducer holding part 513a, 522: Flange 524: Connecting cylinder 525: Cable 621: Universal joint A, B: Power circulation circuit G: Gap G1~G4: Groove L1, R1, L2, R2, L3, R3, L4, R4: Vicinity area T, T1, T2: Test tire

Claims

1. A tire testing apparatus comprising: a rotating drum having a simulated road surface on its outer periphery; a rotation drive unit for rotatably driving the rotating drum; a tire holding unit for holding a test tire in contact with the simulated road surface and enabling it to rotate; a torque generating unit for generating a torque that applies braking or driving force to the test tire; and a relay unit for relaying the power transmission from the rotation drive unit to the torque generating unit; wherein... The aforementioned torque generating unit includes: a housing supported for rotatability; and an electric motor mounted on the aforementioned housing; the aforementioned rotation drive unit rotates and drives the aforementioned housing; wherein the aforementioned relay unit includes: a shaft coupled to the aforementioned rotating drum; and a gearbox connecting the aforementioned shaft to the aforementioned housing of the aforementioned torque generating unit; wherein the aforementioned shaft coupled to the aforementioned rotating drum and the aforementioned torque generating unit are disposed between the aforementioned gearbox and the aforementioned rotating drum.

2. The tire testing apparatus as claimed in claim 1, wherein the gearbox comprises: a first gear, which engages with the aforementioned shaft; and a second gear, which engages with the aforementioned housing of the aforementioned torque generating unit and meshes with the aforementioned first gear.

3. The tire testing apparatus as described in claim 1 or 2, wherein: The aforementioned test tire is connected to the shaft of the aforementioned electric motor; and the aforementioned rotating drum, the aforementioned relay unit, and the aforementioned torque generating unit form a ring-shaped power circulation circuit via the aforementioned test tire.

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