Retread design device, retread design method, and retread design program

Abstract

This retread design device comprises: a collection unit that collects use history data pertaining to a use history since a tire was mounted on a vehicle; a calculation unit that calculates the current fatigue degree of the tire accumulated according to the use history data; and a determination unit that on the basis of a correspondence relationship between a fatigue degree of the tire and a tread thickness required for retreading, determines a tread thickness corresponding to the current fatigue degree of the tire calculated by the calculation unit.

Description

Retread Design Device, Retread Design Method, and Retread Design Program

[0001] The present disclosure relates to a retread design device, a retread design method, and a retread design program.

[0002] A pneumatic tire is made by attaching tread rubber that contacts the road surface to a case composed of a carcass, a belt, an inner liner, a sidewall, etc. The case often can still withstand sufficient use even after the tread rubber has reached the end of its life. Therefore, a new tread rubber is attached (retreaded) to the case of a tire whose tread rubber has worn due to use, and it is reused as a retreaded tire (retread tire) (see, for example, Japanese Patent Application Laid-Open No. 2009-190377). Retreading of tires is utilized as a method for efficient use of tires and reduction of costs for purchasing new tires.

[0003] However, the durability of the case other than the tread rubber affects the tire life after retreading. One of the factors that affects the durability of the case is the heat history (hereinafter referred to as "heat history") that a tire experiences during driving. A case with a large heat history has a shorter remaining durability time until the limit of use compared to a case with a small heat history. Therefore, even if a thick tread rubber is wound around a tire with a relatively short remaining durability time by retreading, the case may reach the limit of use before the tread rubber is completely used up, and the tread rubber may not be able to be completely used up. If the retread rubber cannot be completely used up, it is not preferable from the viewpoint of effective utilization of resources, etc.

[0004] An object of the present disclosure is to provide a retread design device, a retread design method, and a retread design program that can determine an appropriate tread thickness so that the retreaded tread rubber can be completely used up.

[0005] To achieve the above objective, the first embodiment is a retread design apparatus comprising: a collection unit that collects usage history data relating to the usage history of a tire since it has been mounted on a vehicle; a calculation unit that calculates the current fatigue level of the tire accumulated according to the usage history data; and a determination unit that determines the tread thickness corresponding to the current fatigue level of the tire calculated by the calculation unit, based on the correspondence between the fatigue level of the tire and the tread thickness required for retreading.

[0006] The second embodiment is a retread design apparatus according to the first embodiment, wherein the determination unit determines that the tread thickness decreases as the current fatigue level of the tire increases.

[0007] The third embodiment is a retread design apparatus according to the first or second embodiment, wherein the fatigue level of the tire is expressed as any or a combination of the following: thermal history, which is the history of heat received by the tire; internal pressure history, which is the history of internal pressure during use of the tire; and acceleration history, which is the history of acceleration of the vehicle on which the tire is mounted.

[0008] A fourth embodiment is a retread design apparatus according to any one of the first to third embodiments, wherein the collection unit collects state information of the tire at the end of the retread life, which is the time or distance from the time the tire is retreaded until it is completely used up, and further comprises an update unit that updates the correspondence relationship using the state information of the tire.

[0009] The fifth aspect is a retread design method in which a computer performs the following processes: collect usage history data relating to the usage history of a tire since it has been mounted on a vehicle; calculate the current fatigue level of the tire accumulated according to the usage history data; and determine the tread thickness corresponding to the calculated current fatigue level of the tire based on the correspondence between the tire fatigue level and the tread thickness required for retreading.

[0010] The sixth aspect is a retread design program that causes a computer to perform the following processes: collect usage history data relating to the usage history of a tire since it has been mounted on a vehicle; calculate the current fatigue level of the tire accumulated according to the usage history data; and determine the tread thickness corresponding to the calculated current fatigue level of the tire based on the correspondence between the tire fatigue level and the tread thickness required for retreading.

[0011] According to this disclosure, the effect is that an appropriate tread thickness can be determined so that the retreaded tread rubber can be used up completely.

[0012] This figure shows an example of the configuration of a retread design system according to the embodiment. This block diagram shows an example of the functional configuration of a retread design device according to the embodiment. This figure shows an example of usage history data and tools. This graph shows an example of the correspondence between tire fatigue and the tread thickness required for retreading. This schematic diagram shows an example of retread thickness according to tire fatigue. This flowchart shows an example of the processing flow by the retread design program according to the embodiment.

[0013] Embodiments of the technology described herein will be described in detail below with reference to the drawings. Components and processes that perform the same function or operation will be given the same reference numerals throughout the drawings, and redundant explanations may be omitted as appropriate. Furthermore, this disclosure is not limited in any way to the embodiments described below, and can be implemented with appropriate modifications within the scope of the purpose of this disclosure.

[0014] The retread design apparatus according to this embodiment collects usage history data regarding the usage history of a tire after it has been mounted on a vehicle, calculates the current fatigue level of the tire accumulated according to the usage history data, and determines the tread thickness corresponding to the calculated current fatigue level of the tire based on the correspondence between the tire fatigue level and the tread thickness required for retreading. This makes it possible to determine an appropriate tread thickness so that the retreaded tread rubber can be used up completely.

[0015] Figure 1 shows an example of the configuration of the retread design system 100 according to this embodiment.

[0016] As shown in Figure 1, the retread design system 100 according to this embodiment comprises a retread design device 10 that performs retread design and a terminal device 20 used by the user of the vehicle 21. The terminal device 20 and the vehicle 21 are located, for example, in a mine. The retread design device 10 and the terminal device 20 are connected to communicate via a network N. The network N is, for example, a communication network such as the Internet, LAN (Local Area Network), or WAN (Wide Area Network). The retread design device 10 is, for example, a general-purpose computer device such as a server computer or a personal computer (PC). The terminal device 20 is, for example, a terminal device such as a smartphone, tablet terminal, or PC.

[0017] The terminal device 20 is connected to the vehicle 21 in a communication manner and acquires sensor information obtained from sensors 22 installed on the vehicle 21. The sensor information includes, for example, driving speed, acceleration / deceleration / lateral G-force, steering angle, load, and tire pressure.

[0018] The retread design apparatus 10 according to this embodiment includes a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, an input / output interface (I / O) 14, a storage unit 15, a display unit 16, an operation unit 17, and a communication unit 18.

[0019] The CPU 11, ROM 12, RAM 13, and I / O 14 are connected to each other via a bus. The I / O 14 is connected to various functional units, including a storage unit 15, a display unit 16, an operation unit 17, and a communication unit 18. These functional units are capable of communicating with the CPU 11 via the I / O 14.

[0020] The control unit is comprised of a CPU 11, ROM 12, RAM 13, and I / O 14. The control unit may be configured as a sub-control unit that controls the operation of a part of the retread design device 10, or as part of a main control unit that controls the operation of the entire retread design device 10. Integrated circuits or IC chipsets, such as LSIs (Large Scale Integrations), are used in part or all of each block of the control unit. Individual circuits may be used for each of the above blocks, or circuits that integrate part or all of them may be used. The above blocks may be provided as a single unit, or some of the blocks may be provided separately. Furthermore, a part of each of the above blocks may be provided separately. For the integration of the control unit, dedicated circuits or general-purpose processors may be used, not limited to LSIs.

[0021] For example, the storage unit 15 can be an HDD (Hard Disk Drive), an SSD (Solid State Drive), or flash memory. The storage unit 15 stores a retread design program 15A for executing the retread design process according to this embodiment. This retread design program 15A may also be stored in the ROM 12.

[0022] The retread design program 15A may, for example, be pre-installed on the retread design device 10. The retread design program 15A may also be implemented by storing it on a non-volatile storage medium or distributing it via a network N and installing it on the retread design device 10 as appropriate. Examples of non-volatile storage media include CD-ROM (Compact Disc Read Only Memory), magneto-optical disk, HDD, DVD-ROM (Digital Versatile Disc Read Only Memory), flash memory, memory card, etc.

[0023] The display unit 16 may use, for example, a liquid crystal display (LCD), an organic EL (Electroluminescence) display, or the like. The display unit 16 may also have an integrated touch panel. The operation unit 17 is equipped with, for example, a keyboard, mouse, or other device for operation input. The display unit 16 and the operation unit 17 receive various instructions from the user of the retread design apparatus 10. The display unit 16 displays various information such as the results of processing performed in response to the instructions received from the user, and notifications regarding the processing.

[0024] The communication unit 18 is connected to a network N such as the Internet, LAN, or WAN, and is capable of communicating with the terminal device 20 via the network N.

[0025] In this embodiment, the CPU 11 of the retread design apparatus 10 functions as the various parts shown in Figure 2 by writing the retread design program 15A stored in the ROM 12 or memory unit 15 to the RAM 13 and executing it.

[0026] Figure 2 is a block diagram showing an example of the functional configuration of the retread design apparatus 10 according to this embodiment.

[0027] As shown in Figure 2, the CPU 11 of the retread design apparatus 10 according to this embodiment functions as an acquisition unit 11A, a calculation unit 11B, a determination unit 11C, an output unit 11D, and an update unit 11E.

[0028] The collection unit 11A collects usage history data regarding the usage history of the tires since they were mounted on the vehicle 21.

[0029] Figure 3 shows an example of usage history data and tools. Usage history data includes, for example, thermal history during driving, mileage, load, remaining tread amount / installation history, and vehicle information.

[0030] The thermal history during driving is acquired, for example, using a TPMS (Tire Pressure Monitoring System). A TPMS is a system that uses sensors attached to the tires to monitor the internal pressure, internal temperature, etc., of the tires while driving.

[0031] The mileage is obtained, for example, using GPS (Global Positioning System). However, iTrack (registered trademark: Mining Vehicle Tire Monitoring System) may be used instead of GPS. iTrack is a system that integrates and manages data such as tire pressure, internal temperature, vehicle location information, and driving speed.

[0032] The load is obtained, for example, using an FMS (Fleet Management System). An FMS is a system that manages the load on the tire, etc. However, if it is possible to predict from the change in tire pressure, a TPMS may be used instead of an FMS.

[0033] The remaining tread depth (remaining groove depth) and installation history are obtained, for example, using a TMS (Tire Management System). A TMS is a system that manages information such as vehicle information, tire installation history, and the remaining tread depth of the tires.

[0034] The calculation unit 11B calculates the current fatigue level of the tire, which is accumulated according to the usage history data. Here, the fatigue level of the tire is represented, for example, as a thermal history, which is the history of heat the tire has received. Specifically, temperature data measured for the tire (for example, the temperature of the air inside the tire) is acquired, and the thermal history is calculated from the acquired tire temperature data. The temperature data to be acquired is set at a sample rate of one per predetermined time (for example, one every 12 seconds). For example, the thermal history is calculated using the Arrhenius law. The Arrhenius law is known as an equation that expresses the temperature dependence of the reaction rate of organic materials such as plastics and rubber. Here, the calculation of the Arrhenius law is performed using one temperature data per predetermined time. The values ​​obtained from the calculation of the Arrhenius law are totaled over a predetermined tire life period to obtain a total value. This total value is then considered as the thermal history (thermal damage = rubber deterioration) that the tire has received.

[0035] The fatigue level of a tire may be expressed as one or a combination of the following: the thermal history, the internal pressure history (the history of the internal pressure during tire use), and the acceleration history (the history of the acceleration of the vehicle on which the tire is mounted). The internal pressure of a tire, like temperature, is obtained using a sensor (TPMS) attached to the tire, and the fatigue level of the tire may be determined by accumulating and analyzing the history of changes in internal pressure. For example, based on information such as the amount of load applied and for how long from the increase or decrease in internal pressure, how long the tire was driven with internal pressure outside the appropriate range (too high / too low), and how much there was a sudden change in internal pressure (representing overcoming obstacles, entering potholes, etc.), the amount of damage input to the case is calculated, and the fatigue level of the tire is calculated taking into account the durability of the case.

[0036] Furthermore, acceleration can be obtained and calculated from data from accelerometers mounted on the vehicle, TPMS hub, etc., or from GPS data. Rapid acceleration, sudden braking, and driving speed information can be obtained from changes in longitudinal acceleration. Steering operation history can be obtained from changes in lateral acceleration, and lateral load can be determined based on the number and amount of input. Information such as vertical input due to road surface response during driving and altitude changes when climbing slopes can be obtained from changes in vertical acceleration. By using this information individually or in combination, the amount of damage input to the case can be calculated, and the tire fatigue level can be calculated considering the durability of the case.

[0037] For both internal pressure history and acceleration history, one can choose to either accumulate all tire usage history and analyze that information, or acquire and accumulate information when a standard value is exceeded and analyze that information (in this case, the amount of data can be reduced, leading to reduced computational load and costs). Furthermore, by combining any information, including thermal history, it becomes possible to evaluate tire fatigue in more detail. For example, it is thought that accuracy can be improved by capturing chemical degradation of the rubber using thermal history and physical degradation of the rubber using internal pressure history.

[0038] The determination unit 11C determines the tread thickness corresponding to the current tire fatigue level calculated by the calculation unit 11B, based on the correspondence between the tire fatigue level and the tread thickness required for retreading. Specifically, the determination unit 11C uses, for example, the correspondence shown in Figure 4 to determine that the tread thickness decreases as the current tire fatigue level increases.

[0039] Figure 4 is a graph showing an example of the relationship between tire fatigue and the tread thickness required for retreading. In Figure 4, the horizontal axis represents tire fatigue (= thermal history), and the vertical axis represents the retread thickness required for retreading. Figure 5 is a schematic diagram showing an example of retread thickness according to tire fatigue. In Figure 5, the hatched area represents the tread rubber to be retreaded.

[0040] According to the examples of FIGS. 4 and 5, when the total value obtained by the above-mentioned Arrhenius law calculation is H1, the tread thickness required for retread is determined to be R1, and when the total value is H2, the tread thickness required for retread is determined to be R2, and when the total value is H3, the tread thickness required for retread is determined to be R3.

[0041] The output unit 11D outputs the tread thickness for each tire determined by the determination unit 11C to, for example, the display unit 16.

[0042] In addition, the collection unit 11A may collect state information regarding the tire at the end point of the retread life, which is the time or distance until the tire is used up after the retread of the tire. The "state information" here is data including, for example, the thickness of the tread rubber remaining at the end point of the retread life (remaining tread thickness), whether the case is facing the usage limit, etc. In this case, as an example, the update unit 11E updates the correspondence relationship shown in FIG. 4 using the state information regarding the tire. Specifically, for example, the remaining tread thickness is determined by a threshold value at the end point of the retread life. If the remaining tread thickness is greater than or equal to the threshold value, that is, if there is a certain amount remaining, it is considered that the tread thickness at the time of retread was too thick. Therefore, the correspondence relationship is updated so that the tread thickness at the time of retread becomes thinner. Also, if the case is facing the usage limit at the end point of the retread life, it is considered that the tread thickness at the time of retread was insufficient. Therefore, the correspondence relationship is updated so that the tread thickness at the time of retread becomes thicker.

[0043] Next, referring to FIG. 6, the operation of the retread design device 10 included in the retread design system 100 according to the present embodiment will be described.

[0044] FIG. 6 is a flowchart showing an example of the flow of processing by the retread design program 15A according to the present embodiment.

[0045] When the execution of the processing by the retread design program 15A is instructed, the CPU 11 of the retread design device 10 is executed by writing the retread design program 15A stored in the ROM 12 or the storage unit 15 into the RAM 13.

[0046] First, in the mine, the use of the tires mounted on the vehicle 21 is started, and the usage history data regarding the tires is transmitted to the retread design device 10 via the terminal device 20. Then, in the mine, when the tread rubber of the tire decreases and the primary life of the tire ends, the tire after the end of the primary life is transported to the retread factory.

[0047] In the retread factory, retread tires are manufactured from the transported tires after the end of the primary life. Then, in the retread factory, based on the retread thickness provided from the retread design device 10, the tread thickness required for retreading is applied. And in the retread factory, the completed retread tires are transported to the mine.

[0048] In the mine, the use of the transported retread tires is started. Then, in the mine, when the retread rubber of the tire decreases and the secondary life of the tire ends, the status information regarding the tire after the end of the secondary life is transmitted to the retread design device 10 via the terminal device 20.

[0049] In step S101 of FIG. 6, the CPU 11 collects the usage history data regarding the tires mounted on the vehicle 21 from the terminal device 20.

[0050] In step S102, the CPU 11 calculates the current fatigue degree of the tire accumulated according to the usage history data collected in step S101. Here, as described above, the fatigue degree of the tire is represented, for example, as a heat history which is the history of heat received by the tire. Specifically, temperature data measured for the tire (for example, the temperature of the air inside the tire) is acquired, and the heat history is calculated from the acquired temperature data of the tire using the Arrhenius law.

[0051] In step S103, the CPU 11 determines the tread thickness corresponding to the current fatigue degree of the tire calculated in step S102 based on the correspondence relationship between the fatigue degree of the tire and the tread thickness required for retreading (see, for example, FIG. 4). Specifically, the CPU 11 determines, for example, using the correspondence relationship shown in FIG. 4, such that the tread thickness becomes smaller as the current fatigue degree of the tire increases.

[0052] In step S104, the CPU 11 outputs the tread thickness determined in step S103 to, for example, the display unit 16, and the series of processes by this retread design program 15A is completed. The tread thickness determined by the retread design device 10 is provided to the retreading factory.

[0053] As described above, according to this embodiment, the current fatigue level of the tire is calculated from the usage history data, and the tread thickness required for retreading is determined in accordance with the current tire fatigue level. This makes it possible to determine an appropriate tread thickness so that the retreaded tread rubber can be used up completely.

[0054] Furthermore, the technical scope of this disclosure is not limited to the embodiments described above. Various modifications or improvements can be made to the embodiments without departing from the spirit, and such modified or improved forms are also included within the technical scope of this disclosure.

[0055] The disclosure of Japanese Patent Application No. 2024-195372, filed on 7 November 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

Claims

1. A retread design apparatus comprising: a collection unit for collecting usage history data relating to the usage history of a tire since it was mounted on a vehicle; a calculation unit for calculating the current fatigue level of the tire accumulated according to the usage history data; and a determination unit for determining the tread thickness corresponding to the current fatigue level of the tire calculated by the calculation unit, based on the correspondence between the fatigue level of the tire and the tread thickness required for retreading.

2. The retread design apparatus according to claim 1, wherein the determination unit determines that the tread thickness decreases as the current fatigue level of the tire increases.

3. The retread design apparatus according to claim 1, wherein the fatigue level of the tire is expressed as any or a combination of the following: thermal history, which is the history of heat received by the tire; internal pressure history, which is the history of internal pressure during use of the tire; and acceleration history, which is the history of acceleration of the vehicle on which the tire is mounted.

4. The retread design apparatus according to claim 1, wherein the collection unit collects condition information of the tire at the end of the retread life, which is the time or distance from the time the tire is retreaded until it is completely worn out, and the update unit further comprises an update unit that updates the correspondence relationship using the condition information of the tire.

5. A retread design method in which a computer performs the following processes: collects usage history data relating to the usage history of a tire since it has been mounted on a vehicle; calculates the current fatigue level of the tire accumulated according to the usage history data; and determines the tread thickness corresponding to the calculated current fatigue level of the tire based on the correspondence between the tire fatigue level and the tread thickness required for retreading.

6. A retread design program that causes a computer to perform the following processes: collect usage history data relating to the usage history of a tire since it has been mounted on a vehicle; calculate the current fatigue level of the tire accumulated according to the usage history data; and determine the tread thickness corresponding to the calculated current fatigue level of the tire based on the correspondence between the tire fatigue level and the tread thickness required for retreading.

Images