JP4157358B2 - Evaluation method of tire rain groove wonder performance - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention uses a finite element method analysis model of a road surface having a tire, a wheel, and a rain groove with an inclination angle in a tire traveling direction, and an upper peak and a lower peak of a side force acting on the wheel during tire rotation. It is related with the rain groove wonder performance evaluation method of the tire which evaluates a rain groove wonder (RGW) performance by the difference (PP value).
[0002]
[Prior art]
One of the performance evaluation items of a tire is a rain groove wonder (hereinafter referred to as “RGW”) performance. This is because when a car travels on a road surface in which vertical grooves are engraved in parallel with the traveling direction in order to improve the drainage performance of the road, the pattern grooves inscribed on the tires and the rain grooves (vertical grooves on the road surface) ) Interact with each other to cause a wobbling phenomenon (RGW) in the car. Therefore, when designing a tire, this RGW performance must also be an evaluation factor.
[0003]
Conventionally, this type of RGW performance evaluation method has the following two methods.
1) Actual vehicle sensory evaluation method on the actual road The actual vehicle sensory evaluation method is a method in which the RGW performance is sensorially evaluated by attaching the tire to be evaluated to the actual vehicle and running on the rain groove road surface and feeling the grip of the steering wheel while driving. .
2) Indoor test evaluation method using rain groove simulated road drum The indoor evaluation method gives an inclination angle in the tire traveling direction on the surface of the test drum in contact with the tire so that the same running condition as the actual road can be obtained at the indoor test site. Winding a simulated road with multiple rain grooves and measuring the temporal change of the side force generated in the tire during drum rotation, the difference between the upper peak and lower peak of the side force (PP value) This is a method for evaluating RGW performance.
[0004]
[Problems to be solved by the invention]
By the way, since the real tire sensor is used in both the actual vehicle sensory evaluation method and the indoor test evaluation method, the RGW performance evaluation of the design-changed tire requires the trial production / pattern carving of a patternless tire. In some cases, it is necessary to produce a new mold, increasing the tire development cost and prolonging the tire development period.
[0005]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a method capable of evaluating the RGW performance of a tire without producing a tire to be evaluated.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a tire RGW performance evaluation method according to the present invention includes a tire model in which a tire is divided into a plurality of elements and meshed, and a wheel in which a contact range between the tire and the wheel is modeled by a rigid shell element. The RGW performance is analyzed and evaluated by analysis using a finite element method, using a model and a road surface model of a tire contact surface provided with a plurality of rain grooves with inclination angles in the tire traveling direction.
[0007]
According to the above evaluation method, the tire model inner surface is filled with internal pressure, and a longitudinal load is applied to the center node of the wheel model. Then, the road surface model is moved in the direction opposite to the tire traveling direction. Since the time series waveform of the side force acting on the wheel is filtered within the analysis time where the pitch changes, the peak difference (PP value) between the top and bottom is calculated as the evaluation index value of the RGW performance. RGW performance can be evaluated in the same way as in the conventional laboratory test method.
[0008]
In the road surface model, it is preferable that the inclination angle of the rain groove with respect to the tire traveling direction is set to 0.1 to 2.0 degrees in evaluating a suitable RGW performance. Further, if analysis is performed without applying a fine mesh in the tire traveling direction, there may be obtained an analysis result in which the outer peripheral portion of the tire model abnormally enters the rain groove of the road surface model. Therefore, it is necessary to make a fine mesh in the tire traveling direction also in the road surface model so as to match the tire model and the road surface model, and it is preferable to set the mesh length to 5 to 30 mm.
[0009]
The RGW performance evaluation index is calculated by moving the road surface model in the anti-travel direction of the tire, and analyzing the time series waveform of the side force acting on the wheel within the analysis time when the rain groove changes by 1 pitch under the constant road surface speed. It is preferable to perform filtering and calculate the peak difference (PP value) between the upper and lower sides as an evaluation index value of RGW performance.
[0010]
The tire model employs solid elements for the rubber members that make up the tire, and anisotropic shell elements for the composite members made of rubber and cord. When modeling the actual pattern of the tread, It is preferable that the joint portion between the pattern block to be configured and the tire body other than the tread portion is surface-bonded between the pattern block inner surface and the tire body outer surface.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an overall model used in the tire RGW evaluation method according to the present invention, FIG. 2 is a plan view showing the relationship between the tire model and the road surface model, and FIG. 3 is a perspective view showing a tire / wheel combination model. 4 is a perspective view of a tire model, FIG. 5 is a perspective view of a wheel model, FIG. 6 is an enlarged view of a portion A in FIG. 1, FIG. 7 is an enlarged view of a portion B in FIG.
[0012]
As shown in the figure, the RGW evaluation method for the tire 1 is based on the finite element method, creating a tire model 2, a wheel model 3, and a road surface model 4, and then setting the material physical properties, loading the internal pressure / longitudinal load Conditions such as tire rolling conditions and constraint conditions are set, and a finite element method analysis is performed to calculate a side force acting on a rotating wheel as a basis for calculating an RGW performance evaluation index.
[0013]
The tire model 2 is created by the following method. First, as shown in FIG. 4, the target tire is divided into meshes. When modeling the actual pattern of the tread portion, the joint portion between the pattern block constituting the tread portion and the tire body other than the tread portion is joined to the pattern block inner surface and the tire body outer surface. Among the members constituting the tire, a rubber element such as a tread or a sidewall employs a solid element, and an anisotropic shell element is employed for a composite member of a cord and rubber such as a carcass or a belt.
[0014]
As shown in FIG. 5, the wheel model 3 has a contact range between the tire and the wheel as a rigid shell element.
[0015]
The road surface model forms a plurality of rain groups having an inclination angle of 0.1 to 2.0 degrees with respect to the tire traveling direction. Further, if the road surface model 4 is analyzed without applying a fine mesh in the tire traveling direction, an analysis result in which the outer peripheral portion of the tire model abnormally enters the rain groove of the road surface model may be obtained. As shown in FIG. 8, a fine mesh is formed in the tire traveling direction so as to match the tire model with the road surface model. The mesh element length (L) in the X direction (tire traveling direction) in FIG. 7 is preferably set to 5 mm to 30 mm. FIG. 8 illustrates a road surface model in which the interval (pitch) of the grooves 5 is 19.05 mm, the groove width is 2.4 mm, and the groove depth is 5 mm.
[0016]
After modeling the tire, wheel and road surface, analysis conditions such as material property setting, internal pressure / longitudinal load condition, road surface translation condition, tire-road contact condition, wheel-road surface constraint condition, etc. Set.
[0017]
In this embodiment, the test tire is 225 / 60R15, the rim is 15 * 6 1 / 2-JJ, the tire inner surface is filled with internal pressure (200 kPa), and the wheel center is loaded with a longitudinal load (4.9 kPa). The road surface is moved in the tire anti-travel direction.
[0018]
The RGW performance evaluation index is calculated by moving the road surface model in the anti-travel direction of the tire, and analyzing the time series waveform of the side force acting on the wheel within the analysis time when the rain groove changes by 1 pitch under the constant road surface speed. It filters for noise removal, calculates the peak difference (PP value: peak to peak value) of the upper and lower sides, and makes this value the evaluation index value of RGW performance.
[0019]
FIG. 9 shows a correlation diagram between the laboratory test result and the FEM analysis result based on the RGW evaluation method of the present invention regarding the temporal change of the side force. The test tire is 225 / 60R15, the rim is 15 * 6 1 / 2-JJ, the internal pressure is 200 kPa, the longitudinal load is 4.9 kN, and the running speed is 20 km / h. As shown in FIG. 9, a substantially identical waveform is obtained between the laboratory experiment result and the FEM analysis result based on the RGW evaluation method of the present invention.
[0020]
Therefore, according to the evaluation method described above, the tire model is rotated on the road surface model having a plurality of rain grooves with inclination angles in the tire traveling direction, and the side force involved in the RGW is calculated. The RGW performance can be evaluated in the same way as the conventional laboratory test evaluation method without making a prototype.
[0021]
【The invention's effect】
As is apparent from the above description, according to the present invention, the RGW performance is evaluated by the analysis by the finite element method using the tire model, the wheel model and the road surface model. Can be evaluated.
[Brief description of the drawings]
FIG. 1 is an overall model used for an RGW evaluation method for a tire according to the present invention. FIG. 2 is a plan view showing the relationship between the tire model and a road surface model. FIG. 3 is a perspective view showing a tire / wheel combination model. 4 is a perspective view of a tire model. FIG. 5 is a perspective view of a wheel model. FIG. 6 is an enlarged view of a portion A in FIG. 1. FIG. 7 is an enlarged view of a portion B in FIG. 9] Correlation diagram between side force laboratory test results and FEM analysis results 【Explanation of symbols】
1 Tire 2 Tire Model 3 Wheel Model 4 Road Surface Model 5 Groove

Claims (1)

A tire model in which the tire is divided into a plurality of elements and meshed, a wheel model in which the contact range of the tire and the wheel is modeled with a rigid shell element, and a plurality of rain grooves with an inclination angle in the tire traveling direction are provided. When using the road surface model of the tire contact surface and analyzing and evaluating the rain groove wonder performance by finite element method analysis , after filling the tire model inner surface with internal pressure and applying a longitudinal load to the center node of the wheel model, The road surface model is moved in the direction opposite to the tire traveling direction, and the time series waveform of the side force acting on the wheel model is filtered within the analysis time in which the rain groove changes by 1 pitch at a constant road surface speed. Reinguru the tire and calculates as an evaluation index value of the rain groove wander performance Buwanda performance evaluation method.

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