Method and system for detecting damage to the joint of a non-pneumatic tire

Abstract

To provide a method and system for detecting damage to the connecting portion of a non-pneumatic tire, which can accurately detect damage to the connecting portion. [Solution] The method for detecting damage to the connecting portion of spokes 40 of a non-pneumatic tire 1 is a method for detecting damage to the connecting portion of spokes 40 of a non-pneumatic tire 1 having a support structure 10 having an inner annular portion 20, an outer annular portion 30, and spokes 40 connecting the inner annular portion 20 and the outer annular portion 30, and a tread 50 fixed to the outer peripheral surface of the outer annular portion 30. This method comprises the steps of detecting the distance D to the tread surface 51 of the tread 50 of the non-pneumatic tire 1 using a distance sensor 102 attached to the wheel housing 101a of the vehicle 100 (S2, S3), and determining whether or not the spokes 40 are damaged based on the change in distance D (S4, S5, S6).

Description

Technical Field

[0001] The present invention relates to a method for detecting damage to a connecting portion of a non-pneumatic tire and a system for detecting damage to a connecting portion of a non-pneumatic tire.

Background Art

[0002] Conventionally, a non-pneumatic tire is known that includes a support structure containing resin for supporting a load from a vehicle, and a tread located radially outside the support structure in the tire diameter direction and extending along the tire circumferential direction. It is difficult to detect an abnormality (for example, damage to a connecting portion) of a non-pneumatic tire at an early stage, and this exists as a technical problem. Conventionally, for example, an abnormality is detected using a sensor attached to a non-pneumatic tire (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, a method for accurately detecting a failure of a non-pneumatic tire has not yet been established.

[0005] An object of the present invention is to provide a method for detecting damage to a connecting portion of a non-pneumatic tire and a system for detecting damage to a connecting portion of a non-pneumatic tire that can accurately detect damage to the connecting portion.

Means for Solving the Problems

[0006] A method for detecting damage to a connecting portion of a non-pneumatic tire according to one aspect of the present invention is A method for detecting damage to the connecting portion of a non-pneumatic tire, comprising a support structure having an inner annular portion, an outer annular portion, and a connecting portion that connects the inner annular portion and the outer annular portion, and a tread fixed to the outer circumferential surface of the outer annular portion, A step of detecting the distance from the tread surface of the tread of the non-pneumatic tire to the tread surface using a detection device attached to the vehicle body, A step of determining whether or not the connecting portion is damaged based on the change in the distance, It is equipped with.

[0007] A non-pneumatic tire system according to another view of the present invention is: A system for detecting damage to the connecting portion of a non-pneumatic tire, comprising a support structure having an inner annular portion, an outer annular portion, and a connecting portion connecting the inner annular portion and the outer annular portion, and a tread fixed to the outer circumferential surface of the outer annular portion, Non-pneumatic tires, A detection device attached to the vehicle body for detecting the distance from the tread surface of the tread of the non-pneumatic tire, A controller that determines whether or not the connecting part is damaged based on the change in the distance, It is equipped with. [Effects of the Invention]

[0008] According to the present invention, a method for detecting damage to the connecting portion of a non-pneumatic tire and a system for detecting damage to the connecting portion of a non-pneumatic tire are obtained that can accurately detect damage to the connecting portion. [Brief explanation of the drawing]

[0009] [Figure 1] This is a side view showing a non-pneumatic tire according to the first embodiment of the present invention. [Figure 2] This is a cross-sectional view taken along line II-II in Figure 1. [Figure 3] Figure 2 is a perspective view of a portion of a non-pneumatic tire, seen from an oblique angle. [Figure 4] This is a front view of the tread of a non-pneumatic tire. [Figure 5]This is a cross-sectional view of a non-pneumatic tire and a part of the vehicle body, showing the operation of measuring the distance to the tread using a distance sensor. [Figure 6] This is a block diagram showing the control configuration of a non-pneumatic tire coupling failure detection system. [Figure 7] This is a flowchart illustrating a method for detecting damage to the joint of a non-pneumatic tire. [Figure 8] This is a schematic diagram showing the first state of a non-pneumatic tire in the method for detecting damage to the connecting part. [Figure 9] This is a schematic diagram showing the second state of a non-pneumatic tire in the method for detecting damage to the connecting part. [Figure 10] This is a flowchart illustrating a method for detecting damage to the connecting portion of a non-pneumatic tire in a second embodiment of the present invention. [Figure 11] This is a schematic diagram showing the first state of a non-pneumatic tire in the method for detecting damage to the connecting part. [Figure 12] This is a schematic diagram showing the second state of a non-pneumatic tire in the method for detecting damage to the connecting part. [Modes for carrying out the invention]

[0010] (First Embodiment) (Basic structure of non-pneumatic tires) Using Figures 1 to 4, a non-pneumatic tire 1 to which the method for detecting damage to the joint portion of a non-pneumatic tire according to the first embodiment of the present invention is applied will be described. Figure 1 is a side view showing a non-pneumatic tire 1 according to one embodiment of the present invention. Figure 2 is a cross-sectional view taken along line II-II of Figure 1. Figure 3 is a partial perspective view of the non-pneumatic tire 1, taken from an oblique angle from the portion shown in Figure 2. In the following description, the dimensional ratios in the drawings do not necessarily match the actual dimensional ratios, and the dimensional ratios between the drawings do not necessarily match either.

[0011] The non-pneumatic tire 1 includes a support structure 10 and a tread 50. Here, the support structure 10 supports the load from the vehicle. Also, the tread 50 is located outside the support structure 10 in the tire radial direction X and extends along the tire circumferential direction C. Further, the support structure 10 includes an inner annular portion 20, an outer annular portion 30 disposed coaxially with the inner annular portion 20 outside the inner annular portion 20 in the tire radial direction X, and a plurality of spokes 40 as a plurality of connecting portions that connect the inner annular portion 20 and the outer annular portion 30 and are arranged along the tire circumferential direction C.

[0012] (Detailed Structure of Non-Pneumatic Tire) FIG. 1 is a side view of the non-pneumatic tire 1 viewed from a direction parallel to the tire rotation axis (tire meridian), that is, the direction along the front and back directions of the paper surface in FIG. 1. The non-pneumatic tire 1 shown in FIG. 1 is in an unloaded state.

[0013] In FIGS. 1 and 3, C indicates the tire circumferential direction. In FIGS. 1 to 3, X indicates the tire radial direction. In FIGS. 2 and 3, Y indicates the tire width direction. In FIG. 1, the tire width direction Y is the front and back directions of the paper surface. In FIG. 2, E indicates the tire equatorial plane. In FIG. 2, the tire circumferential direction C is the front and back directions of the paper surface.

[0014] The tire circumferential direction C is the direction around the tire rotation axis and is the same direction as the direction in which the non-pneumatic tire 1 rotates. The tire radial direction X is the direction perpendicular to the tire rotation axis. The tire width direction Y is the direction parallel to the tire rotation axis. In FIGS. 2 and 3, one side of the tire width direction Y is shown as Y1, and the other side of the tire width direction Y is shown as Y2. The tire equatorial plane E shown in FIG. 2 is a plane orthogonal to the tire rotation axis and is located at the center of the tire width direction Y.

[0015] The inner annular portion 20 is an annular part along the tire circumferential direction C that constitutes the inner circumference of the non-pneumatic tire 1. The thickness and width of the inner annular portion 20 are set to be constant in order to improve uniformity. A tire wheel (not shown) is placed in the space on the inner circumference side of the inner annular portion 20. The inner circumference of the inner annular portion 20 is fitted and mounted onto the outer circumference of the rim of the tire wheel. With the inner annular portion 20 mounted on the rim, the non-pneumatic tire 1 is mounted on the tire wheel.

[0016] The inner annular portion 20 transmits the rotation of the tire wheel to the spokes 40 and the outer annular portion 30.

[0017] The outer annular portion 30 is an annular part along the tire circumferential direction C that constitutes the outer circumference of the non-pneumatic tire 1. The outer annular portion 30 is arranged concentrically with the inner annular portion 20 on the outer circumference side of the inner annular portion 20.

[0018] As shown in Figure 2, the outer annular portion 30 has a reinforcing layer 32 embedded within the elastic body 31. Here, the reinforcing layer 32 extends along the tire circumferential direction C and is embedded over approximately the entire circumference of the outer annular portion 30 in the tire width direction Y.

[0019] Furthermore, the reinforcing layer 32 does not need to be embedded over the entire tire width direction Y; it is sufficient if it is embedded over approximately the entire tire width direction Y. In this case, the ratio of the length of the reinforcing layer 32 in the tire width direction Y to the length of the elastic body 31 in the tire width direction Y is, for example, 95% or more. Also, the position in the tire radial direction X where the reinforcing layer 32 is embedded is not particularly limited.

[0020] The reinforcing layer 32 preferably contains fiber-reinforced plastic. The fiber-reinforced plastic is not particularly limited as long as it is possible to make the flexural modulus of the reinforcing layer 32 between 10 GPa and 40 GPa, but carbon fiber reinforced plastic (CFRP) or glass fiber reinforced plastic (GFRP) is preferred.

[0021] The thickness of the reinforcing layer 32 is not particularly limited, but for example, it is 2 mm or more and 3 mm or less.

[0022] The material constituting the elastic body 31 is not particularly limited, but examples include thermoplastic elastomers, crosslinked rubber, and other resins, and two or more types may be used in combination. The elastic body 31 may also be a foam made of the above materials.

[0023] The outer annular portion 30 transmits the rotation of the inner annular portion 20 and the spokes 40 to the road surface via the tread 50.

[0024] Multiple spokes 40 connect the inner annular portion 20 and the outer annular portion 30. The inner annular portion 20 and the outer annular portion 30, connected by the multiple spokes 40, are arranged concentrically with respect to each other. Each of the multiple spokes 40 is arranged independently along the tire circumferential direction C. As shown in Figure 1, when the non-pneumatic tire 1 is unloaded, the multiple spokes 40 extend linearly in the radial direction, approximately parallel to the tire radial direction X, when viewed from the side.

[0025] As shown in Figures 2 and 3, the spokes 40 of this embodiment include a plurality of first spokes 41 and a plurality of second spokes 42. The extending direction of both the first spokes 41 and the second spokes 42 is not parallel to the tire radial direction X when viewed along the tire circumferential direction C. The first spokes 41 are inclined toward one side in the tire axial direction, i.e., the tire width direction Y. The second spokes 42 are inclined toward the opposite side from the first spokes 41. The first spokes 41 and the second spokes 42 are arranged alternately in the tire circumferential direction C.

[0026] More specifically, as shown in Figures 2 and 3, the first spoke 41 extends inclined from the Y1 side, which is one side of the outer annular portion 30 in the tire width direction Y, toward the Y2 side, which is the other side of the inner annular portion 20 in the tire width direction Y. The second spoke 42 extends inclined from the Y2 side, which is the other side of the outer annular portion 30 in the tire width direction Y, toward the Y1 side, which is one side of the inner annular portion 20 in the tire width direction Y.

[0027] The inclination angles of the first spoke 41 and the second spoke 42 are the same. Therefore, when viewed from a direction along the tire circumferential direction C, the first spoke 41 and the second spoke 42 adjacent to each other in the tire circumferential direction C are arranged in a roughly X shape.

[0028] The support structure 10, which includes the inner annular portion 20, the outer annular portion 30, and the plurality of spokes 40 described above, is made of resin. The resin that constitutes the support structure 10 is not particularly limited, but examples include thermosetting resins and thermosetting elastomers such as urethane resin, epoxy resin, and phenolic resin, and thermoplastic resins and thermoplastic elastomers such as polyethylene, polyurethane, polyester, and polyamide. It is preferable that the resin that constitutes the support structure 10 contains one or more additives selected from the group consisting of ultraviolet blocking agents, ultraviolet absorbing agents, antioxidants, and light stabilizers in order to ensure the durability of the support structure 10.

[0029] The tread 50 is provided on the outer circumferential surface of the outer annular portion 30 and constitutes the outermost periphery of the non-pneumatic tire 1. The tread 50 has a tread surface 51 on its outer circumferential surface that contacts the road surface. In practice, when the non-pneumatic tire 1 is mounted on a vehicle, the tread surface 51 has a contact portion that contacts the road surface and a non-contact portion that does not contact the road surface. The tread surface 51 of the tread 50 is provided with a tread pattern formed by multiple grooves and land portions, similar to conventional pneumatic tires. Not only land portions but also grooves are included in the tread surface 51.

[0030] The tread surface 51 of the tread 50 will be explained in detail using Figures 2 to 5. Figure 4 is a partial front view of the tread of a non-pneumatic tire. Figure 5 is a cross-sectional view of the non-pneumatic tire 1 and a part of the vehicle body showing the operation of measuring the distance to the tread 50 by the distance sensor 102.

[0031] In this embodiment, the tread surface 51 has a main groove (circumferential groove) formed therein, which includes one central groove 52 and four lateral grooves 54. The central groove 52 is located approximately near the center in the tire width direction Y (in the region including the tire equatorial plane E). The central groove 52 extends in the tire circumferential direction C and is annular. The four lateral grooves 54 are formed in pairs on both sides of the central groove 52 in the tire width direction, spaced apart. The lateral grooves 54 also extend in the tire circumferential direction C and are annular.

[0032] As shown in Figure 4, a wear indicator 53 is provided in the central groove 52. The wear indicator 53 is a mark that indicates the wear limit due to abrasion, and is higher than the bottom surface 52a of the central groove 52 but lower than the contact surface of the land portion of the tread surface 51. There may be one wear indicator 53, or multiple wear indicators 53 may be arranged at intervals in the circumferential direction C of the tire.

[0033] (Overview of the connection failure detection system) The control configuration of the joint damage detection system 100 (hereinafter referred to as "joint damage detection system 100") will be explained using Figure 6. Figure 6 is a block diagram showing the control configuration of the joint damage detection system 100. The joint damage detection system 100 has a controller 103. The joint damage detection system 100 also includes a non-pneumatic tire 1 as the target for detection.

[0034] The controller 103 is a computer system having a processor (e.g., CPU), a memory device (e.g., ROM, RAM, HDD, SSD, etc.), and various interfaces (e.g., A / D converter, D / A converter, communication interface, etc.). The controller 103 performs various control operations by executing programs stored in the memory unit (corresponding to part or all of the memory area of ​​the memory device).

[0035] The joint damage detection system 100 includes a distance sensor 102 (detection device) and a notification device 104. The distance sensor 102 is a sensor that measures the distance to the object to be measured, and is, for example, an optical (laser / infrared) sensor. The notification device 104 is a device that notifies of spoke damage 40 by, for example, image or audio information. The notification device 104 may also be a device that notifies an administrator of spoke damage 40 outside the vehicle. The controller 103 can receive a detection signal from the distance sensor 102. The controller 103 can transmit a control signal to the notification device 104.

[0036] The controller 103 may consist of a single processor, or it may consist of multiple independent processors for each control.

[0037] The functions of some or all of the elements of the controller 103 may be implemented as programs executable on the computer system that constitutes the controller 103. In addition, some of the functions of the elements of the controller 103 may be implemented by custom ICs.

[0038] The controller 103 is connected to sensors and switches for detecting the status of each device, as well as an information input device, although these are not shown in the diagram.

[0039] The coupling damage detection system 100 attaches a distance sensor 102 (detection device) to the body of the vehicle 101, measures the distance D between the vehicle body and the deflated tire 1, and determines whether or not the spoke 40 is damaged based on the change in distance D.

[0040] A distance sensor 102 is provided for each of the four non-pneumatic tires 1. In other words, there are four distance sensors 102. The distance sensors 102 are installed on the vehicle body above the non-pneumatic tires 1. Specifically, as shown in Figure 5, the distance sensor 102 is attached, for example, to the wheelhouse 101a, which is part of the vehicle body, and detects the distance D to the tread surface 51 of the tread 50 of the non-pneumatic tire 1. In this embodiment, the distance D to the tread surface 51 is the distance to the top of the tread surface 51, and more specifically, the distance to the bottom surface 52a of the central groove 52 that extends in the tire circumferential direction C of the tread surface 51. In this embodiment, the distance sensor 102 uses a laser, and the laser irradiation direction is vertically downward.

[0041] The reason for measuring the distance to the bottom of the groove rather than the flat part of the tread surface is that the bottom of the groove does not wear down, so there is no change in distance due to wear. The reason for measuring the central groove 52 rather than the other grooves is that the wear indicator 53 within the central groove 52 can be used as a marking to determine that the data represents one full rotation of the non-pneumatic tire 1 (see below).

[0042] The reason why a change in distance D is an indicator of a spoke 40 failure is as follows: Generally, unlike pneumatic tires, non-pneumatic tires hardly change in circumference under steady state. For example, if a non-pneumatic tire 1 has a reinforcing layer 32 made of fiber-reinforced plastic embedded in the elastic body 31 of the outer annular portion 30, the following phenomenon may occur: Due to the difference in thermal shrinkage during tire manufacturing (thermal shrinkage of spokes 40 >> thermal shrinkage of reinforcing layer 32), the resin of spokes 40 is less likely to shrink due to being pulled by the CFRP of the reinforcing layer 32. As a result, residual stress remains in the spokes 40 in the tensile direction. When a spoke breaks, the constraint between the cut surfaces of the spokes 40 is broken, and the distance between spokes 40 widens. In other words, the tire circumference increases.

[0043] Therefore, as an example, when a faulty spoke 40 is in a contact position, the load-bearing force is weak, so the contact area of ​​the non-pneumatic tire 1 increases, and the distance between the road surface and the rotation axis of the non-pneumatic tire 1 becomes shorter. On the other hand, when a faulty spoke 40 is not in a contact position, the faulty part is bulging. In this case, the distance between the upper part of the vehicle and the non-pneumatic tire 1 is shorter than when the faulty spoke 40 is in a contact position. As another example, if a spoke 40 is damaged by driving while it is not in a contact position, the distance between the upper part of the vehicle and the non-pneumatic tire 1 becomes shorter than before the damage. From the above, when a spoke 40 fails, the distance between the upper part of the vehicle and the non-pneumatic tire 1 changes, and the presence or absence of a failure can be determined by detecting this change in distance.

[0044] (Method for detecting damage to the connecting part of a non-pneumatic tire) Figures 7 to 9 illustrate the method for detecting damage to the joint of a non-pneumatic tire 1. Figure 7 is a flowchart illustrating the method for detecting damage to the joint of a non-pneumatic tire 1. Figure 8 is a schematic diagram showing the first state of the non-pneumatic tire 1 in the method for detecting damage to the joint. Figure 9 is a schematic diagram showing the second state of the non-pneumatic tire 1 in the method for detecting damage to the joint.

[0045] The control flowchart described below is illustrative, and each step can be omitted or replaced as needed. Furthermore, multiple steps may be executed simultaneously, or some or all of them may overlap.

[0046] Furthermore, each block in a control flowchart is not necessarily a single control action; it can be replaced by multiple control actions represented by multiple blocks.

[0047] The operation of each device is the result of commands from the controller 103 to each device, and these are represented by each step of the software application.

[0048] (Step to detect the distance to the tread surface of the tread of a non-pneumatic tire) The following steps S1 to S3 describe the process of detecting the distance D from the tread surface 51 of the tread 50 of the non-pneumatic tire 1.

[0049] (Step S1) As an initial operation, the position of the tire circumferentially C is determined based on the wear indicator 53 located in the central groove 52. Specifically, first, the wear indicator 53 formed in the central groove 52 is detected by the distance sensor 102. Subsequently, the controller 103 determines the position of the non-pneumatic tire 1 circumferentially C based on the detected position of the wear indicator 53.

[0050] (Step S2) As shown in Figure 8, one point on the tread surface 51 in the tire circumferential direction C is designated as the first point a1. The first point a1 is then positioned at the non-contact position (more specifically, at the apex of the tread 50). In this state, the first distance D1, which is the distance between the first point a1 of the non-pneumatic tire 1 and the distance sensor 102, is measured. Specifically, first the distance sensor 102 detects the first distance D1, and then the controller 103 recognizes (receives and stores in the memory unit) the first distance D1 based on the detection signal from the distance sensor 102.

[0051] (Step S3) As shown in Figure 9, the first point a1 is positioned at the ground contact point. For example, the tire is rotated 180° to move the first point a1 from the top of the tire to the ground contact point. In this state, the second distance D2, which is the distance between the tread surface 51 of the non-pneumatic tire 1 and the distance sensor 102, is measured and recorded. Specifically, first the distance sensor 102 detects the second distance D2, and then the controller 103 recognizes (receives and stores in the memory unit) the second distance D2 based on the detection signal from the distance sensor 102.

[0052] In step S2, the points on the tread surface 51 where the first distance D1 is measured may be multiple locations (for example, four locations) in the circumferential direction of the tire. In that case, the measurement of the second distance D2 in step S3 is also performed at multiple locations with each point in contact with the ground.

[0053] (Step to determine if the spokes are damaged) The following steps S4 to S6 describe the process of determining whether or not the spoke 40 is damaged based on the change in distance D.

[0054] (Step S4) The controller 103 calculates the distance difference P1 between the second distance D2 and the first distance D1. The first distance D1 is not much different from the second distance D2 if the spoke 40 at or near the first point a1 is normal. However, if the spoke 40 at or near the first point a1 is damaged, the first point a1 becomes a fault point in a non-contact position, so the first point a1 and its surroundings bulge, and the first distance D1 becomes shorter than the second distance D2. As a result, the distance difference P1 becomes longer.

[0055] (Step S5) The controller 103 compares the distance difference P1 with the threshold Q1 and determines whether the distance difference P1 > threshold Q1. The threshold Q1 is the value at which it is estimated that at least one spoke 40 has been damaged if the distance difference P1 exceeds the threshold Q1. If the answer in step S5 is "Yes", the process proceeds to step S6; otherwise, the process returns to step S1.

[0056] (Step S6) The controller 103 determines that the spoke 40 is damaged when the distance difference P1 exceeds the threshold Q1.

[0057] Furthermore, if steps S2 and S3 are performed at multiple locations in the tire circumferential direction C, steps S4, S5, and S6 are also performed at multiple locations. This allows for accurate detection of damage to the spokes 40 of the non-pneumatic tire 1 across the entire tire circumferential direction C.

[0058] (Step S7) The controller 103 transmits a control signal to the notification device 104 to report the damage to the spoke 40. The notification device 104 notifies the driver of the damage, for example, through a display on the vehicle's screen or by an audible warning. The notification device 104 may also notify a management device located away from the vehicle of the damage.

[0059] In the first embodiment, the above-described method for detecting damage to the connecting portion can accurately detect damage to the spokes 40 of the non-pneumatic tire 1.

[0060] (Second embodiment) In the method for detecting joint damage according to the present invention, the details of the steps of measuring the distance to the tread surface and determining whether or not there is damage to the joint based on the change in distance are not limited to the first embodiment.

[0061] A second embodiment will be described as another example of a method for detecting damage to the connecting portion, using Figures 10 to 12. Figure 10 is a flowchart illustrating a method for detecting damage to the connecting portion of a non-pneumatic tire 1 in the second embodiment of the present invention. Figure 11 is a schematic diagram showing the first state of the non-pneumatic tire 1 in the method for detecting damage to the connecting portion. Figure 12 is a schematic diagram showing the second state of the non-pneumatic tire 1 in the method for detecting damage to the connecting portion. Note that the basic configuration and operation of the second embodiment are the same as those of the first embodiment, so the following explanation will focus on the differences.

[0062] (Step to detect the distance to the tread surface of the tread of a non-pneumatic tire) The following steps S1, S8, and S9 describe the steps for detecting the distance D from the tread surface 51 of the tread 50 of the non-pneumatic tire 1.

[0063] (Step S1) As an initial operation, the position of the tire circumferential C is determined based on the wear indicator 53 in the central groove 52. Specifically, it is first detected by the wear indicator 53 formed in the central groove 52. Subsequently, the position of the non-pneumatic tire 1 circumferential C is determined based on the detected position of the wear indicator 53.

[0064] (Step S8) As shown in Figure 11, a second point b1 is defined as one location on the tread surface 51 in the tire circumferential direction C. The second point b1 is then positioned at a non-contact location (more specifically, at the apex of the tread 50). In this state, the pre-travel distance D3, which is the distance between the second point b1 of the non-pneumatic tire 1 and the distance sensor 102, is measured. Specifically, first the distance sensor 102 detects the pre-travel distance D3, and then the controller 103 recognizes the pre-travel distance D3 based on the detection signal from the distance sensor 102 (received as measurement history and stored in the memory unit). Note that "pre-travel" means the timing before the vehicle is driven a predetermined distance. Step S8 may also be performed while the vehicle is stopped before it is driven a predetermined distance.

[0065] (Step S9) As shown in Figure 11, after step S8, when the vehicle has traveled a predetermined distance, the post-travel distance D4, which is the distance between the non-pneumatic tire 1 and the distance sensor 102, is measured and recorded at the moment the second point b1 reaches the non-contact position (more specifically, the apex of the tread 50). Specifically, first the distance sensor 102 detects the post-travel distance D4, and then the controller 103 recognizes (receives and stores in the memory unit) the post-travel distance D4 based on the detection signal from the distance sensor 102. Note that "post-travel" refers to the timing after the vehicle has traveled a predetermined distance after measuring the pre-travel distance D3. Note that step S9 may also be performed while the vehicle is stopped after traveling a predetermined distance after step S8. Furthermore, it is preferable that step S9 is performed at a predetermined measurement frequency in order to know the change over time of the non-pneumatic tire 1.

[0066] In step S8, the points on the tread surface 51 where the pre-driving distance D3 is measured may be multiple locations (for example, four locations) in the circumferential direction C of the tire. In that case, the measurement of the post-driving distance D4 in step S9 will also be at multiple locations where each point is not in contact with the ground.

[0067] (Step to determine if the spokes are damaged) The following steps S10, S11, and S6 describe the steps for determining whether or not the spoke 40 is damaged.

[0068] (Step S10) The controller 103 calculates the distance difference P2 by subtracting the distance after travel D4 from the distance before travel D3. The distance after travel D4 is not much different from the distance before travel D3 if the spoke 40 at or near the second point b1 is normal. However, if the spoke 40 at or near the second point b1 is damaged, the second point b1 becomes a fault location in a non-ground position when step S9 is executed, so the second point b1 and its surroundings become bulging, and the distance after travel D4 becomes shorter than the distance before travel D3. As a result, the distance difference P2 becomes longer.

[0069] (Step S11) The controller 103 compares the distance difference P2 with the threshold Q2 and determines whether the distance difference P2 > threshold Q2. The threshold Q2 is the value at which it is estimated that at least one spoke 40 has been damaged if the distance difference P2 exceeds the threshold Q2. If the answer in step S11 is "Yes", the process proceeds to step S6; otherwise, the process returns to step S1.

[0070] (Step S6) The controller 103 determines that the spoke 40 is damaged when the distance difference P2 exceeds the threshold Q2.

[0071] Furthermore, if steps S8 and S9 are performed at multiple locations in the tire circumferential direction C, steps S10, S11, and S6 are also performed at multiple locations. This allows for accurate detection of damage to the spokes 40 of the non-pneumatic tire 1 across the entire tire circumferential direction C.

[0072] (Step S7) The controller 103 transmits a control signal to the notification device 104 to report the damage to the spoke 40. The notification device 104 notifies the driver of the damage, for example, through a display on the vehicle's screen or by an audible warning. The notification device 104 may also notify a management device located away from the vehicle of the damage.

[0073] In the second embodiment, the above-described method for detecting damage to the connecting portion can accurately detect damage to the spokes 40 of the non-pneumatic tire 1.

[0074] (Description of the embodiment) <1> The method for detecting damage to the connecting portion of a non-pneumatic tire 1 is: A method for detecting damage to the connecting portion of a non-pneumatic tire 1, which has a support structure 10 having an inner annular portion 20, an outer annular portion 30, and spokes 40 connecting the inner annular portion 20 and the outer annular portion 30, and a tread 50 fixed to the outer circumferential surface of the outer annular portion 30, The steps include detecting the distance D to the tread surface 51 of the tread 50 of the non-pneumatic tire 1 using a distance sensor 102 attached to the vehicle body, A step to determine whether or not the spoke 40 is damaged based on the change in distance D, It is equipped with.

[0075] This allows for accurate detection of damage to the spokes 40 of the non-pneumatic tire 1.

[0076] <2> <1> In the method described above, the distance D to the tread surface 51 is the distance to the bottom surface 52a of the central groove 52 that extends in the tire circumferential direction C of the tread surface 51.

[0077] This allows for accurate detection of damage to the spokes 40 of the non-pneumatic tire 1 across the entire circumferential direction C of the tire.

[0078] <3> <1> or <2> In the method described above, The step of detecting the distance to the tread surface 51 is, Step S1 involves detecting a wear indicator 53 formed in the central groove 52 using a distance sensor 102, The process includes step S1, which determines the position of the non-pneumatic tire 1 in the tire circumferential direction C based on the detection position of the wear indicator 53.

[0079] This makes it possible to determine the position C in the tire circumferential direction of the non-pneumatic tire 1 based on the conventional wear indicator 53.

[0080] <4> <1> ~ <3> In any of the methods described above, The distance D to the tread surface 51 is measured at multiple points C in the circumferential direction of the tire.

[0081] This allows for accurate detection of damage to the spokes 40 of the non-pneumatic tire 1 across the entire circumferential direction C of the tire.

[0082] <5> <1> ~ <4> In any of the methods described above, The step of measuring the distance to the tread surface 51 is: Step S2 involves measuring the first distance D1 to the first point a1 on the tread surface 51, Step S3 includes measuring the second distance D2 to the tread surface 51 when the first point a1 is in contact with the ground, The step to determine whether spoke 40 is damaged is: Step S4 calculates the distance difference P1 between the second distance D2 and the first distance D1, Step S5 involves comparing the distance difference P1 with the threshold Q1, The method includes step S6, which determines that spoke 40 is damaged if the distance difference P1 exceeds a threshold Q1.

[0083] This allows for accurate detection of damage to the spokes 40 of the non-pneumatic tire 1.

[0084] <6> <1> ~ <4> In any of the methods described above, The step of measuring the distance to the tread surface 51 is: Step S8 measures the pre-travel distance D3 to the second point b1 on the tread surface 51, Step S9 includes measuring the distance D4 after travel to the second point b1 on the tread surface 51, The step to determine whether spoke 40 is damaged is: Step S10 calculates the distance difference P2 between the distance before travel D3 and the distance after travel D4, Step S11 involves comparing the distance difference P2 with the threshold Q2, The method includes step S6, which determines that spoke 40 is damaged if the distance difference P2 exceeds a threshold Q2.

[0085] This allows for accurate detection of damage to the spokes 40 of the non-pneumatic tire 1.

[0086] <7> The non-pneumatic tire 1 connection part damage detection system 100 is a system having a support structure 10 having an inner annular portion 20, an outer annular portion 30, and spokes 40 connecting the inner annular portion 20 and the outer annular portion 30, and a tread 50 fixed to the outer circumferential surface of the outer annular portion 30, Non-pneumatic tire 1, A distance sensor 102 is attached to the wheelhouse 101a (vehicle body) of the vehicle 101 and detects the distance D to the tread surface 51 of the tread 50 of the non-pneumatic tire 1, A controller 103 determines whether or not the spoke 40 is damaged based on the change in distance D, It is equipped with.

[0087] This allows for accurate detection of damage to the spokes 40 of the non-pneumatic tire 1.

[0088] (Other embodiments and variations) Although several embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the invention. In particular, the multiple embodiments and modifications described herein can be arbitrarily combined as needed.

[0089] The measurement point for the distance to the tread surface may be the land portion of the tread surface. The distance to the tread surface can be measured at a groove other than the central groove. The point where the distance to the tread surface is measured does not have to be the highest point of the tread surface.

[0090] The shape, position, and other configuration of the wear indicator are not particularly limited. The circumferential position of a non-pneumatic tire may be determined using means other than a wear indicator. The shape of the spokes is not particularly limited. For example, the spokes may have a honeycomb structure. [Explanation of Symbols]

[0091] 1: Non-pneumatic tires 10:Support structure 20: Inner annular section 30:Outer annular part 40: Spoke (connecting part) 50: Tread 51: Tread surface 52: Central groove (groove) 52a: Bottom 53: Wear Indicator 100: Connection failure detection system 101: Vehicle body 101a: Wheelhouse 102: Distance sensor 103: Controller 104: Notification device D: Distance D1: First distance D2: Second distance D3: Distance before driving D4: Distance after driving a1: First point b1: Second point

Claims

1. A method for detecting damage to the connecting portion of a non-pneumatic tire, comprising a support structure having an inner annular portion, an outer annular portion, and a connecting portion connecting the inner annular portion and the outer annular portion, and a tread fixed to the outer peripheral surface of the outer annular portion, A step of detecting the distance from the tread surface of the tread of the non-pneumatic tire to the tread surface using a detection device attached to the vehicle body, A step of determining whether or not the connecting portion is damaged based on the change in the distance, A method for detecting damage to the connecting portion of a non-pneumatic tire, comprising the following features.

2. The method for detecting damage to the connecting portion of a non-pneumatic tire according to claim 1, wherein the distance to the tread surface is the distance to the bottom surface of the grooves extending in the circumferential direction of the tire on the tread surface.

3. The step of detecting the distance to the tread surface is, The steps include detecting a wear indicator formed in the groove using the detection device, A method for detecting damage to the connecting portion of a non-pneumatic tire according to claim 2, comprising the step of determining the position of the non-pneumatic tire in the tire circumferential direction based on the detection position of the wear indicator.

4. The method for detecting damage to the connecting portion of a non-pneumatic tire according to claim 1 or 2, wherein the distance to the tread surface is measured at multiple locations in the circumferential direction of the tire.

5. The step of measuring the distance to the tread surface is: A step of measuring a first distance to a first point on the tread surface, The step includes measuring a second distance to the tread surface when the first point is in contact with the ground, The step of determining whether or not the connecting portion is damaged is: A step of calculating the distance difference between the second distance and the first distance, The steps include comparing the aforementioned distance difference with a threshold, A method for detecting damage to a non-pneumatic tire's connecting portion according to claim 1 or 2, comprising the step of determining that the connecting portion is damaged when the distance difference exceeds the threshold.

6. The step of measuring the distance to the tread surface is: A step of measuring the distance to the second point on the tread surface before travel, The step includes measuring the distance traveled to the second point on the tread surface, The step of determining whether or not the connecting portion is damaged is: A step of calculating the distance difference between the distance before the journey and the distance after the journey, The steps include comparing the aforementioned distance difference with a threshold, A method for detecting damage to a non-pneumatic tire's connecting portion according to claim 1 or 2, comprising the step of determining that the connecting portion is damaged if the distance difference exceeds the threshold.

7. A system for detecting damage to the connecting portion of a non-pneumatic tire, comprising a support structure having an inner annular portion, an outer annular portion, and a connecting portion connecting the inner annular portion and the outer annular portion, and a tread fixed to the outer circumferential surface of the outer annular portion, Non-pneumatic tires, A detection device attached to the vehicle body for detecting the distance from the tread surface of the tread of the non-pneumatic tire, A controller that determines whether or not the connecting part is damaged based on the change in the distance, A non-pneumatic tire coupling damage detection system.

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