Analysis Device, Analysis Method, and Program

Abstract

The sound absorption rate calculation unit that calculates the sound absorption rate based on the design information of the sound absorption structure, the modeling unit that generates a finite element model based on the design information of the tire, and the sound absorption rate setting unit that sets a sound absorption boundary having a sound absorption rate in the finite element model based on the arrangement information of the sound absorption structure with respect to the tire, and a sound pressure analysis unit that analyzes the sound pressure distribution in the internal space of the tire based on the finite element model in which the sound absorption boundary is set.

Description

Technical Field

[0001] The present disclosure relates to an analysis device, an analysis method, and a program.

Background Art

[0002] There is known a technique of disposing a sound absorption structure in a tire attached to a vehicle such as an automobile to reduce resonance sound in the tire generated when the vehicle is running. Further, there is known a technique of analyzing the sound absorption effect by the design and arrangement of the sound absorption structure by numerical analysis such as the finite element method. For example, Non-Patent Document 1 discloses a technique of analyzing the sound pressure distribution in a tire when a sound absorption structure using a Helmholtz resonator is installed based on the finite element method.

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the conventional technique calculates the sound pressure level in the tire space based on a finite element model including the structure of the sound absorption structure installed in the tire, the amount of calculation required for analyzing the sound pressure distribution is large. Further, when the design or arrangement of the sound absorption structure is changed, it is necessary to construct a finite element model each time, so it is difficult to compare the sound absorption effects of various designs or arrangements of the sound absorption structure.

[0005] One aspect of the present disclosure aims to efficiently analyze the sound pressure distribution in the internal space of a tire provided with a sound absorption structure.

Means for Solving the Problems

[0006] The present disclosure has the following configuration.

[0007] [1] An absorption rate calculation unit configured to calculate an absorption rate based on design information of an absorption structure; A modeling unit configured to generate a finite element model based on design information of a tire; An absorption rate setting unit configured to set an absorption boundary having the absorption rate in the finite element model based on arrangement information of the absorption structure with respect to the tire; A sound pressure analysis unit configured to analyze a sound pressure distribution in an internal space of the tire based on the finite element model in which the absorption boundary is set; An analysis device comprising:

[0008] [2] The analysis device according to [1] above, wherein the sound pressure analysis unit is configured to analyze a sound pressure distribution in an internal space of the tire by a coupled analysis of vibration analysis and acoustic analysis. Analysis device.

[0009] [3] The analysis device according to [2] above, wherein the sound pressure analysis unit is configured to analyze a plurality of the sound pressure distributions having different positional relationships between a vibration position and the absorption boundary. Analysis device.

[0010] [4] The analysis device according to [3] above, wherein the sound pressure analysis unit is configured to analyze the sound pressure distribution for each rotation angle when the position of the absorption boundary is rotated at a predetermined rotation angle while fixing the vibration position. Analysis device.

[0011] [5] The analysis device according to [4] above, Further comprising a result output unit configured to output analysis results including the sound pressure distribution for each rotation angle and the maximum value of the sound pressure level for each sound pressure distribution. Analysis device.

[0012] [6] The analysis device according to any one of [1] to [5] above, A design acquisition unit configured to acquire the design information of the sound absorption structure and the design information of the tire, A condition presentation unit configured to output a sound absorption rate curve based on the design information of the sound absorption structure and a resonance frequency based on the design information of the tire, Analysis device further comprising.

[0013] [7] The analysis device according to [6] above, The condition presentation unit is configured to accept adjustment of the design information of the sound absorption structure. Analysis device.

[0014] [8] The analysis device according to [6] or [7] above, The arrangement information includes information in which two or more types of the sound absorption structures having different frequencies at which the sound absorption rate is maximum are arranged on the tire. The sound pressure analysis unit is configured to analyze a broad sound absorption rate curve based on the two or more types of the sound absorption structures. Analysis device.

[0015] [9] The analysis device according to any one of [1] to [8] above, The sound absorption structure is a Helmholtz resonator in which a neck is embedded, and is arranged on the inner surface of the tread portion of the tire. Analysis device.

[0016]

[10] A computer, A procedure for calculating a sound absorption rate based on the design information of the sound absorption structure, A procedure for generating a finite element model based on tire design information, a procedure for setting a sound absorption boundary having the sound absorption rate in the finite element model based on the arrangement information of the sound absorption structure with respect to the tire, a procedure for analyzing the sound pressure distribution in the internal space of the tire based on the finite element model in which the sound absorption boundary is set, and an analysis method for executing the above.

[0017]

[11] On a computer, a procedure for calculating a sound absorption rate based on the design information of the sound absorption structure, a procedure for generating a finite element model based on the tire design information, a procedure for setting a sound absorption boundary having the sound absorption rate in the finite element model based on the arrangement information of the sound absorption structure with respect to the tire, a procedure for analyzing the sound pressure distribution in the internal space of the tire based on the finite element model in which the sound absorption boundary is set, and a program for causing the above to be executed.

Advantages of the Invention

[0018] According to one aspect of the present disclosure, the sound pressure distribution in the internal space of a tire provided with a sound absorption structure can be efficiently analyzed.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13A

Figure 13B

Figure 14

Figure 15

[0020] Hereinafter, each embodiment of the present disclosure will be described with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant descriptions are omitted.

[0021] [Embodiment] One embodiment of the present disclosure is an analysis system for analyzing the sound pressure distribution in the internal space of a tire in which a sound absorption structure is disposed. In this embodiment, the sound absorption structure may be an embedded Helmholtz resonator. A Helmholtz resonator is a structure having a hollow member with an opening and a neck portion connected so as to extend the length of the opening. An embedded Helmholtz resonator is a Helmholtz resonator in which an extended portion of the opening by the neck portion is located inside the hollow member.

[0022] Inside a tire attached to a vehicle, a resonance sound, also called a column resonance sound or the like, is generated when the vehicle is running. The column resonance sound has a resonance frequency corresponding to the shape of the tire. As an example, in a passenger car, it resonates at approximately 200 Hz, and noise, also called road noise or the like, is generated.

[0023] By disposing a sound absorption structure designed to exhibit high sound absorption characteristics at the resonance frequency of the tire inside the tire, the column resonance sound generated inside the tire when the vehicle is running can be suppressed. The more sound absorption structures are disposed in the tire, the more the sound absorption performance improves, but the weight of the tire may increase and affect the running of the vehicle. In addition, adding a sound absorption structure to the tire also increases the manufacturing cost. Therefore, when disposing a sound absorption structure in the tire, it is necessary to consider an appropriate design and arrangement in consideration of a balance such as weight, shape, laying interval, laying cost, and sound absorption effect.

[0024] In this embodiment, the object is to efficiently analyze the sound pressure distribution in the internal space of a tire provided with a sound absorption structure. For this purpose, in this embodiment, a sound absorption boundary having a sound absorption rate calculated based on the design information of the sound absorption structure is set in a finite element model constructed based on the design information of the tire, and the sound pressure distribution in the internal space of the tire is analyzed based on the finite element model in which the sound absorption boundary is set.

[0025] On one hand, according to the present embodiment, since the structure of the sound absorption structure is not included in the finite element model, the analysis of the sound pressure distribution based on the finite element model can be performed with a small amount of calculation. On the other hand, according to the present embodiment, since the sound pressure distribution in the inner space of the tire when the sound absorption structure is installed in various designs and arrangements can be analyzed in a short time, the optimal design and arrangement of the sound absorption structure can be efficiently designed.

[0026] <Overall Configuration> The overall configuration of the analysis system in the present embodiment will be described with reference to FIG. 1. FIG. 1 is a block diagram showing an example of the overall configuration of the analysis system.

[0027] As shown in FIG. 1, the analysis system 1000 includes an analysis device 10 and a terminal device 20. The analysis device 10 and the terminal device 20 are connected so as to be capable of data communication via a communication network N such as a LAN (Local Area Network) or the Internet.

[0028] The analysis device 10 is an example of an information processing device such as a personal computer, a workstation, or a server that analyzes the sound pressure distribution in the inner space of the tire provided with the sound absorption structure. The analysis device 10 receives design data indicating the shapes of the tire and the sound absorption structure from the terminal device 20, and analyzes the sound pressure distribution in the inner space of the tire provided with the sound absorption structure. The analysis device 10 transmits the analysis result of the sound pressure distribution in the inner space of the tire to the terminal device 20.

[0029] The terminal device 20 is an example of an information processing terminal such as a personal computer, a smartphone, or a tablet terminal operated by a user of the analysis system 1000. The terminal device 20 transmits the design data specified by the user to the analysis device 10. The terminal device 20 receives the analysis result from the analysis device 10 and presents it to the user.

[0030] Note that the overall configuration of the analysis system 1000 shown in FIG. 1 is an example, and there can be various system configuration examples depending on the application and purpose. For example, one or more of the analysis device 10 and the terminal device 20 may be included in multiple units in the analysis system 1000. For example, the analysis device 10 may be realized by multiple computers or as a cloud computing service. For example, the analysis device 10 may be realized by a stand-alone computer. The classification of devices such as the analysis device 10 and the terminal device 20 shown in FIG. 1 is an example.

[0031] <Hardware Configuration> The hardware configuration of the analysis system 1000 will be described with reference to FIG. 2. The analysis device 10 and the terminal device 20 included in the analysis system 1000 are realized by, for example, a computer. FIG. 2 is a block diagram showing an example of the hardware configuration of a computer.

[0032] As shown in FIG. 2, the computer 500 has a CPU (Central Processing Unit) 501, a ROM (Read Only Memory) 502, a RAM (Random Access Memory) 503, an HDD (Hard Disk Drive) 504, an input device 505, a display device 506, a communication I / F (Interface) 507, and an external I / F 508. The CPU 501, the ROM 502, and the RAM 503 form a so-called computer. Each hardware of the computer 500 is interconnected via a bus line 509. Note that the input device 505 and the display device 506 may be connected to the external I / F 508 for use.

[0033] The CPU 501 is an arithmetic device that realizes the control and functions of the entire computer 500 by reading programs and data from a storage device such as the ROM 502 or the HDD 504 onto the RAM 503 and executing the processing.

[0034] The ROM 502 is an example of a non-volatile semiconductor memory (storage device) that can retain programs and data even when the power is turned off. The ROM 502 functions as a main storage device that stores various programs, data, etc. necessary for the CPU 501 to execute various programs installed in the HDD 504. Specifically, the ROM 502 stores boot programs such as BIOS (Basic Input / Output System) and EFI (Extensible Firmware Interface) that are executed when the computer 500 is started up, as well as data such as OS (Operating System) settings and network settings.

[0035] The RAM 503 is an example of a volatile semiconductor memory (storage device) in which programs and data are erased when the power is turned off. The RAM 503 is, for example, DRAM (Dynamic Random Access Memory), SRAM (Static Random Access Memory), etc. The RAM 503 provides a working area where various programs installed in the HDD 504 are expanded when executed by the CPU 501.

[0036] The HDD 504 is an example of a non-volatile storage device that stores programs and data. Programs and data stored in the HDD 504 include an OS, which is basic software that controls the entire computer 500, and applications that provide various functions on the OS. Note that the computer 500 may use a storage device (e.g., SSD: Solid State Drive, etc.) that uses a flash memory as a storage medium instead of the HDD 504.

[0037] The input device 505 is a touch panel, operation keys or buttons, a keyboard or a mouse, a microphone for inputting audio data such as voice, etc. that are used by the user to input various signals.

[0038] The display device 506 is composed of a display such as a liquid crystal or an organic EL (Electro-Luminescence) that displays a screen, a speaker that outputs sound data such as voice, and the like.

[0039] The communication I / F 507 is an interface for connecting to a communication network and enabling the computer 500 to perform data communication.

[0040] The external I / F 508 is an interface with an external device. Examples of external devices include the drive device 510.

[0041] The drive device 510 is a device for setting the recording medium 511. The recording medium 511 here includes media that optically, electrically, or magnetically record information, such as CD-ROMs, flexible disks, magneto-optical disks, etc. The recording medium 511 may also include semiconductor memories that electrically record information, such as ROMs, flash memories, etc. Thus, the computer 500 can read and / or write to the recording medium 511 via the external I / F 508.

[0042] Note that various programs installed in the HDD 504 are installed, for example, when the distributed recording medium 511 is set in the drive device 510 connected to the external I / F 508 and the various programs recorded on the recording medium 511 are read by the drive device 510. Alternatively, various programs installed in the HDD 504 may be installed by being downloaded via the communication I / F 507 from the communication network N or another network different from the communication network N.

[0043] <Functional Configuration> The functional configuration of the analysis device 10 will be described with reference to FIG. 3. FIG. 3 is a block diagram showing an example of the functional configuration of the analysis device.

[0044] As shown in FIG. 3, the analysis device 10 includes a design acquisition unit 110, a modeling unit 120, a frequency calculation unit 130, a sound absorption rate calculation unit 140, a condition presentation unit 150, a sound absorption rate setting unit 160, a sound pressure analysis unit 170, and a result output unit 180.

[0045] The design acquisition unit 110, the modeling unit 120, the frequency calculation unit 130, the sound absorption rate calculation unit 140, the condition presentation unit 150, the sound absorption rate setting unit 160, the sound pressure analysis unit 170, and the result output unit 180 are realized by the processing executed by the CPU 501 for the program expanded from the HDD 504 shown in FIG. 2 onto the RAM 503.

[0046] The design acquisition unit 110 acquires design data. The design data includes tire design information, sound absorption structure design information, and arrangement information indicating the position where the sound absorption structure is installed with respect to the tire. The design acquisition unit 110 may receive the design data from the terminal device 20. The design acquisition unit 110 may accept the input of the design data via the input device 505 of the analysis device 10.

[0047] FIGS. 4A and 4B are diagrams for explaining an example of tire design information. FIG. 4A is a side view of the tire T. FIG. 4B is a cross-sectional view taken along line A-A of the tire T shown in FIG. 4A. As shown in FIGS. 4A and 4B, the tire design information may include the tire width w1, the tire outer diameter r1, the tire inner diameter (rim diameter) r2, and the tire thickness t1.

[0048] FIGS. 5A and 5B are diagrams for explaining an example of sound absorption structure design information. FIG. 5A is a cross-sectional view of an example of a sound absorption structure, an embedded Helmholtz resonator R. FIG. 5B is a top view of the embedded Helmholtz resonator R shown in FIG. 5A. As shown in FIGS. 5A and 5B, the design information of the embedded Helmholtz resonator R may include the outer radius r3 of the resonance cylinder, the inner length h1 of the resonance cylinder, the surface thickness t2 of the resonance cylinder, the embedded neck length h2, the inner radius r4 of the embedded neck, and the thickness t3 of the embedded neck.

[0049] FIG. 6 is a diagram for explaining an example of the arrangement information of the sound absorption structure. FIG. 6 is a side view of a tire T in which four sound absorption structures R1 to R4 are installed at intervals of 45°. As shown in FIG. 6, the installation positions of the sound absorption structures R1 to R4 may be represented by arrangement angles θ1 to θ4 with the vertical upper side of the tire T being 0°. The arrangement information of the sound absorption structure may include a plurality of arrangement angles θ1 to θ4 indicating the installation positions of the plurality of sound absorption structures R1 to R4. Note that the sound absorption structures R1 to R4 are installed inside the tire T. The sound absorption structures R1 to R4 may be installed on the inner surface of the tread portion of the tire T.

[0050] The design information of the tire may include the physical property information of the rubber, the physical property information of the rim, and the physical property information of the air. As an example, the physical property information of the rubber may include density, elastic modulus, and Poisson's ratio. As an example, the physical property information of the rim may include density, elastic modulus, and Poisson's ratio. As an example, the physical property information of the air may include density and sound velocity. The physical property information of the rubber, the physical property information of the rim, and the physical property information of the air may be stored in advance in a storage device such as the HDD 504 of the analysis device 10.

[0051] Based on the shape information of the tire acquired by the design acquisition unit 110, the modeling unit 120 generates a finite element model of the tire and the inner space of the tire. Hereinafter, the finite element model of the tire and the inner space of the tire is also referred to as a "tire model".

[0052] Based on the tire model generated by the modeling unit 120, the frequency calculation unit 130 calculates the resonance frequency of the inner space of the tire. The frequency calculation unit 130 may calculate the resonance frequency by a coupled analysis of vibration analysis and acoustic analysis. In the coupled analysis, the physical property information of the rubber, the physical property information of the rim, and the physical property information of the air may be used.

[0053] Specifically, the frequency calculation unit 130 analyzes the resonance frequency of the air column resonance sound generated by the vibration of the tire. As an example, the frequency calculation unit 130 applies a load vibration to a predetermined position of the tire model and calculates the sound pressure level on a predetermined evaluation surface. The position where the load vibration is applied corresponds to the ground contact surface when the tire is mounted on the vehicle. The evaluation surface may be a cross-section at a position facing the vibration position across the rotation axis of the tire (i.e., a position rotated 180° from the vibration position). The frequency calculation unit 130 calculates the sound pressure level for each frequency by performing frequency decomposition on the air column resonance sound on the evaluation surface. The frequency calculation unit 130 acquires the frequency at which the sound pressure level shows a peak as the resonance frequency.

[0054] The sound absorption rate calculation unit 140 calculates the sound absorption rate curve of the sound absorption structure based on the design information of the sound absorption structure acquired by the design acquisition unit 110. The sound absorption rate calculation unit 140 may calculate the sound absorption rate for each frequency based on the shape of the sound absorption structure shown in the design information of the sound absorption structure and generate a sound absorption rate curve showing the frequency characteristics of the sound absorption rate. As an example of the sound absorption rate, the sound absorption rate calculation unit 140 may calculate the acoustic impedance.

[0055] A method for calculating the acoustic impedance based on the shape of the sound absorption structure is disclosed, for example, in the following Reference 1. However, the method disclosed in Reference 1 is only an example, and any method that can calculate the acoustic impedance based on the shape of the sound absorption structure may be used.

[0056] 〔Reference 1〕Sibo Huang, Xinsheng Fang, Xu Wang, Badreddine Assouar, Qian Cheng, Yong Li, "Acoustic perfect absorbers via Helmholtz resonators with embedded apertures", The Journal of the Acoustical Society of America, vol. 145, pp. 254-262, 2019.

[0057] The condition presentation unit 150 outputs analysis conditions. The analysis conditions may include the resonance frequency calculated by the frequency calculation unit 130 and the sound absorption rate curve calculated by the sound absorption rate calculation unit 140. The condition presentation unit 150 may transmit an analysis condition screen for displaying the analysis conditions to the terminal device 20. The condition presentation unit 150 may display an analysis condition screen for displaying the analysis conditions on the display device 506 of the analysis device 10.

[0058] The analysis condition screen may display the design information of the sound absorption structure used for calculating the sound absorption rate curve. The condition presentation unit 150 may accept adjustment of the design information of the sound absorption structure according to the user's operation on the analysis condition screen. When the condition presentation unit 150 accepts the adjustment of the design information of the sound absorption structure, the design acquisition unit 110 acquires design data including the adjusted design information of the sound absorption structure.

[0059] Based on the arrangement information acquired by the design acquisition unit 110, the sound absorption rate setting unit 160 sets a sound absorption boundary having the sound absorption rate calculated by the sound absorption rate calculation unit 140 on the tire model generated by the modeling unit 120. The sound absorption rate setting unit 160 may specify the sound absorption rate corresponding to the resonance frequency calculated by the frequency calculation unit 130 based on the sound absorption rate curve calculated by the sound absorption rate calculation unit 140, and set a sound absorption boundary having the sound absorption rate on the tire model. As an example, when the buried type Helmholtz resonator is installed at each installation position shown in the arrangement information, the sound absorption rate setting unit 160 may set the acoustic impedance corresponding to the resonance frequency in the region where the bottom surface facing the opening of the buried type Helmholtz resonator is located.

[0060] The sound absorption rate setting unit 160 may determine the area of the sound absorption boundary for setting the sound absorption rate based on the design information of the sound absorption structure. As an example, the sound absorption rate setting unit 160 may calculate the area of the sound absorption boundary based on the outer radius r3 of the resonance cylinder. The sound absorption rate setting unit 160 may adjust the area of the sound absorption boundary so that the sound absorption characteristics of the sound absorption boundary match the sound absorption characteristics measured in the experiment.

[0061] The sound pressure analysis unit 170 analyzes the sound pressure distribution in the tire inner space based on the tire model in which the sound absorption rate setting unit 160 has set the sound absorption boundary. The sound pressure analysis unit 170 may analyze a plurality of sound pressure distributions with different positional relationships between the vibration position and the sound absorption boundary. For example, the sound pressure analysis unit 170 may analyze the sound pressure distribution for each rotation angle when the position of the sound absorption boundary is rotated at a predetermined rotation angle while fixing the vibration position.

[0062] The result output unit 180 outputs the analysis result by the sound pressure analysis unit 170. The result output unit 180 transmits an analysis result screen for displaying the analysis result to the terminal device 20. The result output unit 180 may display an analysis result screen for displaying the analysis result on the display device 506 of the analysis device 10.

[0063] The analysis result includes the sound pressure distribution analyzed by the sound pressure analysis unit 170. The analysis result may include the sound pressure distribution for each rotation angle. The analysis result may include the maximum sound pressure level for each sound pressure distribution. In other words, the analysis result may include the maximum sound pressure level for each rotation angle.

[0064] <Processing procedure> The analysis method executed by the analysis system 1000 will be described with reference to FIG. 7. FIG. 7 is a flowchart showing an example of the analysis method.

[0065] In step S1, the terminal device 20 receives the input of design data by the user. The terminal device 20 transmits the received design data to the analysis device 10.

[0066] The analysis device 10 receives the design data from the terminal device 20. The design acquisition unit 110 of the analysis device 10 acquires the received design data. The design acquisition unit 110 extracts the tire design information from the design data and sends it to the modeling unit 120. The design acquisition unit 110 extracts the design information and arrangement information of the sound absorption structure from the design data and sends it to the sound absorption rate calculation unit 140.

[0067] In step S2, the modeling unit 120 of the analysis device 10 receives the tire design information from the design acquisition unit 110. The modeling unit 120 generates a tire model based on the tire design information. The modeling unit 120 sends the tire model to the frequency calculation unit 130 and the sound absorption rate setting unit 160.

[0068] In step S3, the frequency calculation unit 130 of the analysis device 10 receives the tire model from the modeling unit 120. The frequency calculation unit 130 calculates the resonance frequency of the tire inner space based on the tire model. The frequency calculation unit 130 sends the resonance frequency to the condition presentation unit 150 and the sound absorption rate setting unit 160.

[0069] In step S4, the sound absorption rate calculation unit 140 of the analysis device 10 receives the design information and the arrangement information of the sound absorption structure from the design acquisition unit 110. The sound absorption rate calculation unit 140 generates a sound absorption rate curve of the sound absorption structure based on the design information of the sound absorption structure. The sound absorption rate calculation unit 140 sends the sound absorption rate curve of the sound absorption structure to the condition presentation unit 150. Also, the sound absorption rate calculation unit 140 sends the sound absorption rate curve of the sound absorption structure and the arrangement information of the sound absorption structure to the sound absorption rate setting unit 160.

[0070] In step S5, the condition presentation unit 150 of the analysis device 10 receives the resonance frequency from the frequency calculation unit 130. Also, the condition presentation unit 150 receives the sound absorption rate curve from the sound absorption rate calculation unit 140. The condition presentation unit 150 transmits an analysis condition screen including the resonance frequency and the sound absorption rate curve to the terminal device 20.

[0071] The terminal device 20 receives the analysis condition screen. The terminal device 20 displays the analysis condition screen on the display device 506. The user of the terminal device 20 may refer to the resonance frequency and the sound absorption rate curve displayed on the analysis condition screen. The user of the terminal device 20 may adjust the design information of the sound absorption structure on the analysis condition screen. Also, the user of the terminal device 20 may instruct an analysis based on the design conditions displayed on the analysis condition screen.

[0072] In step S6, the condition presentation unit 150 of the analysis device 10 determines whether to adjust the design information of the sound absorption structure. If the user adjusts the design information of the sound absorption structure on the analysis condition screen, the condition presentation unit 150 may determine to adjust the design information of the sound absorption structure. On the other hand, if the user instructs an analysis based on the design conditions on the analysis condition screen, the condition presentation unit 150 may determine not to adjust the design information of the sound absorption structure.

[0073] If it is determined to adjust the design information of the sound absorption structure (YES), the design acquisition unit 110 acquires the adjusted design information of the sound absorption structure, and returns the process to step S4. On the other hand, if it is determined not to adjust the design information of the sound absorption structure (NO), the condition presentation unit 150 proceeds to step S7.

[0074] When returning the process to step S4, the sound absorption rate calculation unit 140 calculates the sound absorption rate curve of the sound absorption structure based on the adjusted design information of the sound absorption structure. Then, the analysis device 10 executes steps S5 and S6 again. In this way, until the user instructs an analysis, the analysis device 10 repeatedly executes the calculation of the sound absorption rate curve and the presentation of the analysis conditions.

[0075] In step S7, the sound absorption rate setting unit 160 of the analysis device 10 receives the tire model from the modeling unit 120. Also, the sound absorption rate setting unit 160 receives the resonance frequency from the frequency calculation unit 130. Further, the sound absorption rate setting unit 160 receives the sound absorption rate curve and the arrangement information of the sound absorption structure from the sound absorption rate calculation unit 140.

[0076] The sound absorption rate setting unit 160 specifies the sound absorption rate corresponding to the resonance frequency based on the sound absorption rate curve. The sound absorption rate setting unit 160 sets a sound absorption boundary having the specified sound absorption rate in the tire model based on the arrangement information of the sound absorption structure. The sound absorption rate setting unit 160 sends the tire model with the sound absorption boundary set to the sound pressure analysis unit 170.

[0077] In step S8, the sound pressure analysis unit 170 of the analysis device 10 receives the tire model with the sound absorption boundary set from the sound absorption rate setting unit 160. Based on the tire model with the sound absorption boundary set, the sound pressure analysis unit 170 analyzes the sound pressure distribution in the tire inner space. Specifically, while fixing the vibration position of the tire model, the sound pressure analysis unit 170 analyzes the sound pressure distribution for each rotation angle when the position of the sound absorption boundary is rotated at a predetermined rotation angle. Also, the sound pressure analysis unit 170 obtains the maximum sound pressure level for each sound pressure distribution. The sound pressure analysis unit 170 sends the sound pressure distribution for each rotation angle and the maximum sound pressure level for each sound pressure distribution to the result output unit 180.

[0078] In step S9, the result output unit 180 of the analysis device 10 receives the sound pressure distribution for each rotation angle and the maximum sound pressure level for each sound pressure distribution from the sound pressure analysis unit 170. The result output unit 180 transmits an analysis result screen including the sound pressure distribution for each rotation angle and the maximum sound pressure level for each sound pressure distribution to the terminal device 20.

[0079] The terminal device 20 receives the analysis result screen. The terminal device 20 displays the analysis result screen on the display device 506. The user of the terminal device 20 may refer to the analysis result displayed on the analysis result screen. The user of the terminal device 20 may consider the arrangement of the sound absorption structure for the tire or the design of the sound absorption structure. The user of the terminal device 20 may change the arrangement information or design information of the sound absorption structure for the tire and input design data including the changed arrangement information or design information into the terminal device 20.

[0080] <User Interface> The user interface of the analysis device 10 will be described with reference to FIGS. 8 and 9. The user interface of the analysis device 10 may include an analysis condition screen (see FIG. 8) and an analysis result screen (see FIG. 9). The user interface of the analysis device 10 may be displayed on the display device 506 of the terminal device 20 or the display device 506 of the analysis device 10.

[0081] ≪Analysis Condition Screen≫ FIG. 8 is a diagram showing an example of an analysis condition screen. The analysis condition screen is a screen that displays analysis conditions and accepts adjustment of design information of the sound absorption structure.

[0082] As shown in FIG. 8, the analysis condition screen 600 has a design adjustment unit 610, a calculation result display unit 620, a graph display unit 630, and a continue button 640.

[0083] The design adjustment unit 610 displays the design information of the sound absorption structure in an adjustable manner. In the example shown in FIG. 8, the design adjustment unit 610 displays the incident angle 611, the outer radius 612 of the resonance cylinder, the length 613 of the resonance cylinder, the surface thickness 614 of the resonance cylinder, the buried neck length 615, the inner radius 616 of the buried neck, and the thickness 617 of the buried neck. Note that the incident angle 611 is the incident angle of sound waves to the opening of the buried Helmholtz resonator. The incident angle 611 may be adjusted according to the orientation when the buried Helmholtz resonator is installed in the tire.

[0084] As an example, the design adjustment unit 610 displays the design information of the sound absorption structure with a slider bar that can set an arbitrary value between the minimum value and the maximum value. By the user operating any slider bar, the value of the design information corresponding to the slider bar is changed. When the value of the design information is changed, the condition presentation unit 150 accepts the adjustment of the design information of the sound absorption structure.

[0085] The calculation result display unit 620 displays the calculation result based on the design information of the sound absorption structure. In the example shown in FIG. 8, the calculation result display unit 620 displays the resonance cylinder volume 621, the maximum sound absorption rate 622, and the frequency 623 of the maximum sound absorption rate. When the design information of the sound absorption structure is adjusted by the design adjustment unit 610, the calculation result display unit 620 is updated to the calculation result recalculated based on the adjusted design conditions.

[0086] The graph display unit 630 displays the sound absorption rate curve of the sound absorption structure and the resonance frequency of the tire inner space. In the example shown in FIG. 8, the graph display unit 630 displays a sound absorption rate curve 631 showing the relationship between the frequency and the sound absorption rate, with the horizontal axis representing the frequency and the vertical axis representing the sound absorption rate, and the resonance frequency 632 of the tire inner space. The peak value of the sound absorption rate curve 631 displayed on the graph display unit 630 corresponds to the maximum sound absorption rate 622. Also, the frequency indicating the peak of the sound absorption rate curve 631 corresponds to the frequency 623 of the maximum sound absorption rate.

[0087] The sound absorption structure installed in the tire inner space preferably exhibits the maximum sound absorption characteristics at the resonance frequency of the tire inner space. The user may adjust the design information of the sound absorption structure so that the peak of the sound absorption rate curve 631 displayed on the graph display unit 630 coincides with the resonance frequency 632.

[0088] The continue button 640 is a button for instructing the analysis of the sound pressure distribution based on the analysis conditions displayed on the analysis condition screen 600. When the user presses the continue button 640, the condition presentation unit 150 receives an instruction for analysis based on the design conditions.

[0089] ≪Analysis Result Screen≫ FIG. 9 is a diagram showing an example of the analysis result screen. The analysis result screen is a screen that receives the input of design data and displays the analysis results.

[0090] As shown in FIG. 9, the analysis result screen 700 includes a calculation setting unit 710, a tire design input unit 720, a sound absorption structure design input unit 730, an arrangement information input unit 740, a sound pressure distribution display unit 750, and a maximum value display unit 760.

[0091] The calculation setting unit 710 receives the input of calculation settings. In the example shown in FIG. 9, the calculation setting unit 710 displays a resonance frequency 711. The resonance frequency 711 may be input with a desired resonance frequency by the user, or may be automatically input with a resonance frequency calculated based on the design information of the tire.

[0092] The tire design input unit 720 receives the input of tire design information. In the example shown in FIG. 9, the tire design input unit 720 displays the tire width 721, the tire outer diameter 722, the tire inner diameter 723, and the tire thickness 724.

[0093] The sound absorption structure design input unit 730 receives the input of sound absorption structure design information. In the example shown in FIG. 9, the sound absorption structure design input unit 730 displays the resonance cylinder outer radius 731, the resonance cylinder inner length 732, the resonance cylinder surface thickness 733, the embedded neck length 734, the embedded neck inner radius 735, and the embedded neck thickness 736.

[0094] The arrangement information input unit 740 receives the input of the arrangement information of the sound absorption structure. In the example shown in FIG. 9, the arrangement information input unit 740 displays the arrangement angles 741 to 744 of the sound absorption structure. The input fields for the arrangement angles may be increased or decreased by any number. The increase or decrease of the input fields may be performed by the user's operation.

[0095] The sound pressure distribution display unit 750 visualizes the sound pressure distribution in the tire inner space. In the example shown in FIG. 9, the sound pressure distribution in the tire inner space is shown by displaying shades according to the sound pressure level values in the perspective view of the tire. The sound pressure distribution display unit 750 may display the sound pressure distribution for each rotation angle in a switchable manner. The sound pressure distribution display unit 750 may display the change in the sound pressure distribution as an animation by continuously displaying the sound pressure distribution for each rotation angle.

[0096] The maximum value display unit 760 displays a graph showing the maximum sound pressure level for each rotation angle. In the example shown in FIG. 9, the maximum value display unit 760 displays a curve showing the relationship between the rotation angle and the maximum sound pressure level, with the horizontal axis being the rotation angle and the vertical axis being the maximum sound pressure level. Note that in the example shown in FIG. 9, the maximum sound pressure level when two sound absorption structures are installed in the tire is shown.

[0097] On the analysis result screen 700, in the initial display, the sound pressure distribution display section 750 and the maximum value display section 760 may not be displayed. On the analysis result screen 700, when the user inputs design data into the calculation setting section 710, the tire design input section 720, the sound absorption structure design input section 730, and the arrangement information input section 740, the analysis condition screen 600 is displayed. On the analysis condition screen 600, when the user presses the continue button 640, the analysis result screen 700 with the sound pressure distribution display section 750 and the maximum value display section 760 displayed is shown.

[0098] [Other Embodiments] FIG. 10 is a diagram showing another example of the analysis condition screen. As shown in FIG. 10, the analysis condition screen 600B has a design adjustment section 610, a calculation result display section 620, a graph display section 630, and a continue button 640, similar to the analysis condition screen 600 shown in FIG. 8. However, the analysis condition screen 600B is different from the example in FIG. 8 in that the used material volume 624 is included in the calculation result display section 620. The used material volume 624 different from the example shown in FIG. 8 will be described.

[0099] The used material volume 624 is a result calculated based on the resonance cylinder outer radius 612, the resonance cylinder length 613, the resonance cylinder surface thickness 614, the embedded neck length 615, the embedded neck inner radius 616, and the embedded neck thickness 617, which are set as design information of the sound absorption structure, and is the volume occupied by the sound absorption structure itself. By displaying the used material volume 624, the user can imagine the volume occupied by the sound absorption structure arranged in the internal space of the tire.

[0100] In FIG. 10, it has been described as showing the used material volume 624 of the sound absorption structure. However, by giving the density of the material constituting the sound absorption structure in advance, the used material weight may be displayed instead of the used material volume. There is concern that when the weight of the sound absorption structure increases, it may affect the rotation and vibration of the tire. By displaying the used material weight, the user can imagine the additional weight added by arranging the sound absorption structure in the tire.

[0101] FIG. 11 is a diagram showing another example of the analysis result screen. As shown in FIG. 11, the analysis result screen 700B has a calculation setting section 710, a tire design input section 720, a sound absorption structure design input section 730, a layout information input section 740, a sound pressure distribution display section 750, and a maximum value display section 760, similar to the analysis result screen 700 shown in FIG. 9. However, the analysis result screen 700B is different from the example of FIG. 9 in that the air temperature 712 and the air pressure 713 are included in the calculation setting section 710. The air temperature 712 and the air pressure 713 different from the example shown in FIG. 9 will be described.

[0102] When the air temperature inside the tire changes by, for example, 20°C, the resonance frequency changes by 10 Hz. In the design of the sound absorption structure, a change of 10 Hz in the resonance frequency is at a level that cannot be ignored. By providing a setting for the air temperature that can reflect the air temperature during actual measurement, the user can appropriately compare with the measured values. Actually, since the sound absorption rate curve of the sound absorption structure also slides following the air column resonance frequency according to the change amount of the air temperature inside the tire, there is no problem.

[0103] The physical property information of the rubber and the physical property information of the rim included in the design data may include the physical property values when the temperature changes. Also, the physical property information of the air included in the design data may include the physical property values when the air temperature and the air pressure change.

[0104] In the previous description, it has been described that only one type of sound absorption structure having a sound absorption frequency is arranged in the internal space of the tire, but the analysis system 1000 can also be an analysis target when two or more types of sound absorption structures having different sound absorption frequencies are arranged.

[0105] More specifically, the analysis device 10 may set a sound absorption boundary having different sound absorption rates by changing the arrangement angle. For example, as shown in FIG. 12, the sound absorption structure A may be arranged at 0°, 90°, 180°, 270°, and the sound absorption structure B may be arranged at 45°, 135°, 225°, 315°. Thereby, the user can consider combining two or more types of sound absorption structures according to the frequency of the sound pressure level to maximize the quietness.

[0106] The sound pressure distribution in the inner space of the tire can change due to changes in the air temperature and air pressure inside the tire. At this time, by arranging sound absorption structures with different sound absorption frequencies according to the change in the sound pressure distribution, efficient sound absorption can be achieved.

[0107] FIG. 13A is a diagram for explaining a graph display when two types of sound absorption structures with different sound absorption frequencies are arranged. FIG. 13B is a diagram for explaining a graph display when three types of sound absorption structures with different sound absorption frequencies are arranged.

[0108] When arranging two or more sound absorption structures with different sound absorption frequencies, the sound absorption rate calculation unit 140 calculates a broadened sound absorption rate curve based on each sound absorption rate curve of the sound absorption structures. The calculation method of the broad curve is disclosed in, for example, Reference 2 below. However, the method disclosed in Reference 2 is only an example, and any method can be used as long as it can calculate the broad curve based on a plurality of sound absorption rate curves.

[0109] 〔Reference 2〕Shaohua Bi, Enshuai Wang, Xinmin Shen, Fei Yang, Xiaonan Zhang, Xiaocui Yang, Qin Yin, Cheng Shen, Ming Xu, Junlin Wan, "Enhancement of sound absorption performance of Helmholtz resonators by space division and chamber grouping", Applied Acoustics, vol. 207, 2023, 109352.

[0110] When arranging two or more sound absorption structures with different sound absorption frequencies, by displaying the broadened sound absorption rate curve, the user can confirm the effect of arranging a plurality of sound absorption structures with different sound absorption frequencies.

[0111] FIG. 14 is a diagram showing another example of the analysis condition screen. As shown in FIG. 14, the analysis condition screen 600C may have a plurality of analysis condition tabs 601 (601-1, 601-2, 601-3). The analysis condition screen 600C may have as many analysis condition tabs 601 as the number of sound absorption structures that may be arranged on the tire. The analysis condition tabs 601 may be added and deleted by a user operation. Information indicating the sound absorption structure (for example, device A, device B, etc.) may be set as the label of the analysis condition tab 601. The label of the analysis condition tab 601 may be edited by a user operation.

[0112] The analysis condition tab 601 has a design adjustment unit 610, a calculation result display unit 620, a graph display unit 630, a continue button 640, and a display switching unit 650. That is, compared with the analysis condition screen 600B shown in FIG. 10, the analysis condition screen 600B is different in that the display switching unit 650 is added.

[0113] The display switching unit 650 displays in a selectable manner the display method of the sound absorption rate curve. As an example, the display switching unit 650 may be radio buttons that can select single display and broad display. The display switching unit 650 may be any screen component that can select the display method, and may be configured by, for example, a combo box or a toggle switch.

[0114] The graph display unit 630 displays the sound absorption rate curve of the sound absorption structure according to the display method selected in the display switching unit 650. When single display is selected in the display switching unit 650, the graph display unit 630 displays the sound absorption rate curve of the sound absorption structure input to the currently displayed analysis condition tab 601. On the other hand, when broad display is selected in the display switching unit 650, the graph display unit 630 displays a broad curve calculated based on the sound absorption rate curves of a plurality of sound absorption structures input to all the analysis condition tabs 601 that the analysis condition screen 600B has.

[0115] FIG. 15 is a diagram showing another example of the analysis result screen. As shown in FIG. 15, the analysis result screen 700C has a calculation setting section 710, a tire design input section 720, a sound absorption structure design input section 730, a layout information input section 740, a sound pressure distribution display section 750, and a maximum value display section 760. The analysis result screen 700C has different input items in the layout information input section 740 as compared with the analysis result screen 700B shown in FIG. 11.

[0116] The layout information input section 740 may receive input of the sound absorption structure name and the angle. The sound absorption structure name is the name of the sound absorption structure. The sound absorption structure name may be the label of the analysis condition tab 601 of the analysis condition screen 600B. The sound absorption structure name may be any information as long as it can specify the design information of the sound absorption structure. The angle is the layout angle of the sound absorption structure. The number of input fields for the sound absorption structure name and the angle may be increased or decreased arbitrarily. The increase or decrease of the input fields may be performed by the user's operation.

[0117] <Effects of the Embodiment> The analysis device 10 in the present embodiment calculates the sound absorption rate based on the design information of the sound absorption structure, generates a finite element model based on the design information of the tire, sets a sound absorption boundary having the sound absorption rate in the finite element model based on the layout information of the sound absorption structure with respect to the tire, and analyzes the sound pressure distribution in the internal space of the tire based on the finite element model in which the sound absorption boundary is set.

[0118] On one side, according to the present embodiment, the sound pressure distribution in the internal space of the tire provided with the sound absorption structure can be analyzed with a small amount of calculation. On the other side, according to the present embodiment, the optimal design and layout of the sound absorption structure can be efficiently designed.

[0119] The analysis device 10 may analyze the sound pressure distribution in the internal space of the tire by a coupled analysis of vibration analysis and acoustic analysis. According to the present embodiment, based on the finite element model in which the sound absorption boundary is set, the sound pressure distribution in the internal space of the tire can be analyzed with a small amount of calculation.

[0120] The analysis device 10 may analyze a plurality of sound pressure distributions with different positional relationships between the vibration position and the sound absorption boundary. The analysis device 10 may analyze the sound pressure distribution for each rotation angle when the position of the sound absorption boundary is rotated at a predetermined rotation angle while fixing the vibration position. According to the present embodiment, the sound pressure distribution considering the usage state of the tire can be analyzed.

[0121] The analysis device 10 may output an analysis result including the sound pressure distribution for each rotation angle and the maximum value of the sound pressure level for each sound pressure distribution. According to the present embodiment, the analysis result can be displayed in a manner that is easy for the user to understand.

[0122] The analysis device 10 may output a sound absorption rate curve based on the design information of the sound absorption structure and a resonance frequency based on the design information of the tire. The analysis device 10 may accept adjustment of the design information of the sound absorption structure. According to the present embodiment, since the analysis conditions can be confirmed before analysis, the sound pressure distribution in the tire inner space can be analyzed under appropriate analysis conditions.

[0123] The sound absorption structure may be a Helmholtz resonator in which a neck is embedded. The sound absorption structure may be installed on the inner surface of the tread portion of the tire. According to the present embodiment, the sound pressure distribution in the tire inner space when an embedded-type Helmholtz resonator is installed on the inner surface of the tread portion of the tire can be efficiently analyzed.

[0124] [Supplementary Explanation] Each function of the embodiment described above can be realized by one or a plurality of processing circuits. Here, the "processing circuit" in this specification includes a processor programmed to execute each function by software, such as a CPU (Central Processing Unit) or GPU (Graphics Processing Unit) implemented by an electronic circuit, and an ASIC (Application Specific Integrated Circuit), DSP (Digital Signal Processor), FPGA (Field Programmable Gate Array) designed to execute each function described above, and devices such as conventional circuit modules.

[0125] As described above in detail for the embodiments of the present disclosure, the embodiments disclosed this time are illustrative in all respects and not restrictive. The embodiments can be modified and improved in various forms without departing from the scope and gist of the appended claims. Matters described in the above plurality of embodiments can also adopt other configurations and can be combined within a non - conflicting range.

[0126] This application claims the priority of International Application PCT / JP2024 / 18485, filed on May 20, 2024, with the Japan Patent Office as the receiving office, and incorporates its entire contents by reference herein.

Explanation of Reference Numerals

[0127] 10: Analysis device 20: Terminal device 110: Design acquisition unit 120: Modeling unit 130: Frequency calculation unit 140: Sound absorption rate calculation unit 150: Condition presentation unit 160: Sound absorption rate setting unit 170: Sound pressure analysis unit 180: Result output unit 1000: Analysis system

Claims

1. A sound absorption coefficient calculation unit is configured to calculate the sound absorption coefficient based on the design information of the sound-absorbing structure, A modeling unit configured to generate a finite element model based on tire design information, A sound absorption coefficient setting unit is configured to set a sound absorption boundary having the sound absorption coefficient in the finite element model based on the arrangement information of the sound absorption structure relative to the tire, A sound pressure analysis unit is configured to analyze the sound pressure distribution in the internal space of the tire based on the finite element model in which the sound absorption boundary is set, An analytical device equipped with the following features.

2. The analysis apparatus according to claim 1, The sound pressure analysis unit is configured to analyze the sound pressure distribution in the internal space of the tire by coupled analysis of vibration analysis and acoustic analysis. Analysis device.

3. The analysis apparatus according to claim 2, The sound pressure analysis unit is configured to analyze multiple sound pressure distributions in which the positional relationship between the vibration position and the sound absorption boundary is different. Analysis device.

4. The analysis apparatus according to claim 3, The sound pressure analysis unit is configured to analyze the sound pressure distribution for each rotation angle when the position of the sound absorption boundary is rotated by a predetermined rotation angle while the vibration position is fixed. Analysis device.

5. The analysis apparatus according to claim 4, The system further includes a result output unit configured to output analysis results including the sound pressure distribution for each rotation angle and the maximum sound pressure level for each sound pressure distribution. Analysis device.

6. An analysis apparatus according to any one of claims 1 to 5, A design acquisition unit is configured to acquire design information for the sound-absorbing structure and the design information for the tire, A condition suggestion unit is configured to output a sound absorption coefficient curve based on the design information of the sound-absorbing structure and a resonance frequency based on the design information of the tire, An analysis device further equipped with additional features.

7. The analysis apparatus according to claim 6, The condition presentation unit is configured to accept adjustments to the design information of the sound-absorbing structure. Analysis device.

8. The analysis apparatus according to claim 6, The arrangement information includes information that two or more sound-absorbing structures with different frequencies that result in the maximum sound absorption coefficient are arranged in the tire. The sound pressure analysis unit is configured to analyze a broad sound absorption coefficient curve based on the two or more sound-absorbing structures. Analysis device.

9. An analysis apparatus according to any one of claims 1 to 5, The sound-absorbing structure is a Helmholtz resonator with an embedded neck, and is positioned on the inner surface of the tire tread. Analysis device.

10. Computers Procedure for calculating the sound absorption coefficient based on the design information of the sound-absorbing structure, The procedure for generating a finite element model based on tire design information, A procedure for setting a sound-absorbing boundary having the sound absorption coefficient in the finite element model based on the arrangement information of the sound-absorbing structure relative to the tire, A procedure for analyzing the sound pressure distribution in the internal space of the tire based on the finite element model in which the sound absorption boundary is set, An analysis method to perform this task.

11. On the computer, Procedure for calculating the sound absorption coefficient based on the design information of the sound-absorbing structure, The procedure for generating a finite element model based on tire design information, A procedure for setting a sound-absorbing boundary having the sound absorption coefficient in the finite element model based on the arrangement information of the sound-absorbing structure relative to the tire, A procedure for analyzing the sound pressure distribution in the internal space of the tire based on the finite element model in which the sound absorption boundary is set, A program to execute.

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