JP2017020851A - Method for evaluating wear performance of rubber material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evaluate wear performance of rubber material in a short period of time.SOLUTION: A method for evaluating wear performance of rubber material using a computer is provided. The method comprises: a step (S1) of setting a plurality of measurement areas in rubber material for measuring a wear amount of the rubber material; a step (S2) of setting conditions of contact between the rubber material and a grind stone for making the rubber material wear such that the respective measurement areas are ununiformly worn; a step (S3) of pushing the rubber material against the grind stone to make the rubber material wear on the basis of the condition of contact; a step (S4) of measuring a wear amount of each of the measurement areas; a step (S8) of causing the computer to calculate wear energy of a rubber material model in an area corresponding to the measurement area; and a step (S10) of evaluating wear performance of the rubber material on the basis of a relationship between the wear amount of the rubber material and the wear energy of the rubber material model, which are corresponded to each other in the measurement area.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for evaluating the wear performance of rubber materials.

  Conventionally, a method for evaluating the wear performance of a rubber material has been proposed (see, for example, Patent Document 1 below). In the evaluation method disclosed in Patent Document 1, for example, a first step of pressing a rubber material against a grindstone and wearing it, and a second step of bringing a rubber material model input to a computer into contact with the grindstone model are performed. . The rubber material model and the grindstone model are modeled with a finite number of elements.

  And in the evaluation method of the following patent document 1, the amount of wear of the rubber material measured in the first step and the wear energy of the rubber material model calculated in the second step are calculated between the rubber material and the grindstone. The wear performance of the rubber material is evaluated based on the relationship corresponding to a plurality of contact conditions.

Japanese Patent Laid-Open No. 2015-45578

  Generally, in the first test in which a rubber material is worn, the amount of wear of the rubber material is measured by uniformly wearing the rubber material. For this reason, in order to measure a plurality of different wear amounts, it is necessary to wear the rubber material a plurality of times for each contact condition. Further, in the second step in which the rubber material model is brought into contact with the grindstone model, the wear energy of the rubber material model is calculated for each contact condition as in the first step.

  As described above, in the evaluation method of Patent Document 1 described above, in order to obtain the relationship between the wear amount and the wear energy, it is necessary to perform the first step and the second step for each contact condition. There was a problem that it took a lot of time to evaluate the performance.

  The present invention has been devised in view of the above circumstances, and has as its main object to provide a method capable of evaluating the wear performance of a rubber material in a short time.

  The present invention is a method for evaluating the wear performance of a rubber material using a computer, the step of setting a plurality of measurement regions for measuring the wear amount of the rubber material in the rubber material, A step of setting a contact condition between the rubber material and a grindstone for wearing the rubber material so that the wear of each measurement region is non-uniform, the rubber material based on the contact condition A process of pressing against the grinding wheel to wear, a process of measuring the amount of wear in each measurement region, a process of inputting a rubber material model in which the rubber material is modeled by a finite number of elements to the computer, and the computer. A step of inputting a grindstone model in which the grindstone is modeled by a finite number of elements, and the computer contacts the rubber material model with the grindstone model based on the contact condition. A step in which the computer calculates wear energy of the rubber material model in a region corresponding to the measurement region, and a wear amount of the rubber material and the rubber material that the computer corresponds in the measurement region. The method includes a step of evaluating the wear performance of the rubber material based on the relationship with the wear energy of the model.

  In the method for evaluating the wear performance of the rubber material according to the present invention, the rubber material has a cylindrical shape on an outer peripheral surface that rolls on the grindstone, and the outer peripheral surface of the plurality of measurement regions has an axial direction. It is desirable to be set by dividing into

  In the method for evaluating the wear performance of the rubber material according to the present invention, the wear amount is preferably an average value of wear amounts obtained at different positions in the circumferential direction of the measurement region.

  In the method for evaluating the wear performance of the rubber material according to the present invention, the contact condition is preferably a slip angle of the rubber material with respect to the grindstone.

  The method for evaluating the wear performance of a rubber material according to the present invention includes a step of setting a plurality of measurement regions for measuring the amount of wear of the rubber material in the rubber material, so that the wear of each measurement region becomes non-uniform. The process of setting the contact condition between the material and the grinding wheel for wearing the rubber material, the process of pressing the rubber material against the grinding wheel based on the contact condition, and the amount of wear in each measurement area The process of measuring is included. Thereby, in the evaluation method of the present invention, it is possible to acquire a plurality of wear amounts different for each measurement region.

  The evaluation method of the present invention includes a step of inputting a rubber material model obtained by modeling a rubber material with a finite number of elements into a computer, a step of inputting a grindstone model obtained by modeling a grindstone with a finite number of elements, The computer includes contacting the rubber material model with the grindstone model based on the contact condition and calculating the wear energy of the rubber material model in an area corresponding to the measurement area. Thereby, in the evaluation method of the present invention, it is possible to acquire a plurality of wear energies that differ for each measurement region.

  Furthermore, the evaluation method of the present invention includes a step in which the computer evaluates the wear performance of the rubber material based on the relationship between the wear amount of the rubber material corresponding to the measurement region and the wear energy of the rubber material model. . In the evaluation method of the present invention, since the relationship between the wear amount and the wear energy of the rubber material can be obtained based on the plurality of wear amounts and the plurality of wear energies, the wear performance of the rubber material is evaluated in a short time. be able to.

It is a perspective view which shows an example of the computer for performing the rubber material evaluation method of this embodiment. It is a perspective view of a rubber material and an abrasion tester. It is a perspective view which shows an example of the rubber material of this embodiment, and a measuring apparatus. It is a flowchart which shows an example of the process sequence of the rubber material evaluation method of this embodiment. It is a flowchart which shows an example of the process sequence of the contact condition setting process of this embodiment. It is a top view of a rubber material and a grindstone. It is a graph which shows an example of the outer diameter D1a before abrasion of each measurement area | region, and the outer diameter D1b after abrasion. It is a perspective view of a rubber material model. It is a perspective view of a rubber material model and a grindstone model. FIG. 10 is a plan view of FIG. 9. It is a flowchart which shows an example of the process sequence of the wear energy calculation process of this embodiment. (A) is a side view of a rubber material model that rolls a grinding wheel model, and (b) is a plan view of (a). It is a graph which shows an example of the wear energy Ew of each area | region. It is a graph which shows the relationship between the abrasion loss Lw of a rubber material, and the abrasion energy Ew of a rubber material model. It is a perspective view which shows the rubber material of other embodiment of this invention. It is a graph which shows the relationship between the abrasion loss Lw of the rubber material of a comparative example, and the abrasion energy Ew of a rubber material model.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The method for evaluating the wear performance of a rubber material according to this embodiment (hereinafter sometimes simply referred to as “rubber material evaluation method”) is for evaluating the wear performance of a rubber material using a computer. In this rubber material evaluation method, the relationship between the amount of wear of the rubber material and the wear energy based on the amount of wear of the rubber material obtained by the wear tester and the wear energy of the rubber material model obtained using a computer. Is required.

  FIG. 1 is a perspective view showing an example of a computer for executing the rubber material evaluation method of the present embodiment. The computer 1 includes a main body 1a, a keyboard 1b, a mouse 1c, and a display device 1d. The main body 1a is provided with, for example, an arithmetic processing unit (CPU), a ROM, a working memory, a storage device such as a magnetic disk, and disk drive devices 1a1 and 1a2. The storage device stores in advance software or the like for executing the rubber material evaluation method of the present embodiment. Therefore, the computer 1 is configured as a simulation device for evaluating the wear performance of the rubber material.

  FIG. 2 is a perspective view of the rubber material and the wear tester. FIG. 3 is a perspective view showing an example of the rubber material and the measuring apparatus according to the present embodiment. As shown in FIG. 3, the rubber material 2 of the present embodiment is formed in a cylindrical shape having, for example, an outer peripheral surface 2 s that rolls on a grinding wheel 4 (shown in FIG. 2). Further, a hole 2o penetrating in the thickness direction is provided in the center of the rubber material 2.

  The outer peripheral surface 2s of the rubber material 2 of the present embodiment is formed as a smooth surface without unevenness, but is not limited to such a mode. For example, the outer peripheral surface 2s may be provided with a groove (not shown) imitating a tread pattern of a tire (not shown) or may be previously worn (for example, uneven wear).

  The outer diameter D1 of the rubber material 2 can be appropriately set, but is preferably set to 40 to 80 mm. In addition, when the outer diameter D1 of the rubber material 2 is less than 40 mm, the rubber material 2 is worn at an early stage, and there is a possibility that a measurement error increases. Further, if the outer diameter D1 of the rubber material 2 exceeds 80 mm, it takes time to wear the rubber material 2, and the evaluation efficiency of the rubber material 2 may be deteriorated. The outer diameter D1 of the rubber material 2 is preferably 50 mm or more, and preferably 70 mm or less.

  The width W1 of the rubber material 2 can be set as appropriate, but is preferably set to 5 to 40 mm. If the width W1 of the rubber material 2 is less than 5 mm, the wear amount distribution in the axial direction of the rubber material 2 may be reduced. On the contrary, if the width W1 of the rubber material 2 exceeds 40 mm, the stress in the surface becomes non-uniform, and there is a possibility that the relationship between the wear amount of the rubber material and the wear energy of the rubber material model cannot be obtained correctly. From such a viewpoint, the width W1 of the rubber material 2 is preferably 15 mm or more, and preferably 30 mm or less.

  As shown in FIG. 2, the wear tester 3 is configured as an indoor wear tester for evaluating the wear resistance of a rubber material from the amount of wear of the rubber material 2, for example.

  The wear testing machine 3 of this embodiment includes a grinding wheel 4 for wearing the rubber material 2, a rubber material support 5 that supports the rubber material 2, and a base 6 that supports the grinding wheel 4 and the rubber material support 5. It is comprised including. The grindstone 4, the rubber material support 5 and the base 6 are accommodated in a housing (not shown), for example. The casing is provided with a switch for operating and stopping the wear tester 3.

  The grindstone 4 includes a disc-shaped rotary table 4a and a grindstone surface 4b fixed to the rotary table 4a. The rotary table 4 a is fixed to a vertical shaft 7 that protrudes upward from the base 6. Further, the vertical shaft 7 is fixed to an electric motor (not shown) incorporated in the base 6. Such a grindstone 4 can rotate around a vertical axis by driving an electric motor or the like.

  A plurality of abrasive grains (not shown) are formed on the grindstone surface 4b. The particle size of the grindstone surface 4b can be set as appropriate, but is preferably set to 24 to 240 mesh. If the particle size is less than 24 mesh, the contact between the rubber material 2 and the abrasive grains becomes small, the wear amount becomes small, and the wear of the rubber material 2 tends to vary. Further, the time required for wear of the rubber material 2 may be increased. On the contrary, when the particle size exceeds 240 mesh, the contact between the rubber material 2 and the abrasive grains becomes large, and the rubber material 2 is hardly worn. For this reason, there exists a possibility that the time which abrasion of the rubber material 2 requires may become long. Furthermore, since the wear amount of the rubber material 2 is reduced, the rubber material 2 is likely to vary in wear. From such a viewpoint, the particle size of the grindstone surface 4b is preferably 30 mesh or more, preferably 120 mesh or less, more preferably 60 mesh or less.

  The rubber material support portion 5 includes a support portion 9 that supports the rubber material 2 so as to be rotatable around a horizontal axis, and a cylinder mechanism 10 that moves the rubber material 2.

  The support portion 9 has a horizontal shaft 9a with one end inserted into the hole 2o (shown in FIG. 3) of the rubber material 2, and a horizontal shaft fixed pivotally supporting the other end of the horizontal shaft 9a around the horizontal axis. Part 9b. The horizontal shaft 9a is preferably supported by the horizontal shaft fixing portion 9b via a bearing portion 13 such as a bearing, for example.

  The cylinder mechanism 10 includes a rod 10a that expands and contracts in the longitudinal direction, a cylinder 10b that supports the rod 10a so that it can be inserted and removed, and an electric motor (not shown) that expands and contracts the rod 10a. One end of a plate-like connecting member 11 is fixed to the tip of the rod 10a, and the horizontal shaft fixing portion 9b is fixed to the other end of the connecting member 11. Thereby, the cylinder mechanism 10 can move the rubber material 2 vertically with respect to the grindstone surface 4b by the expansion and contraction of the up-and-down method of the rod 10a. Further, the cylinder 10b of the present embodiment is supported on the base 6 so as to be rotatable about a vertical axis. Thereby, the rubber material support part 5 can set slip angle (theta) 1 (shown in FIG. 6) of the rubber material 2 with respect to the grindstone surface 4b of the grindstone 4.

  As shown in FIGS. 2 and 3, the wear tester 3 of the present embodiment is provided with a measuring device 12 for measuring the dimensions (for example, the outer diameter D1) of the outer peripheral surface 2s of the rubber material 2. ing. The measuring device 12 of this embodiment is configured as a laser measuring device. As shown in FIG. 3, the measuring device 12 includes a housing 12 a and an irradiation unit 12 b that irradiates the rubber material 2 with the laser light Ls. As shown in FIG. 2, the housing 12 a is disposed above the rubber material 2 and is fixed to the connecting member 11 via a support member 14. Such a measuring device 12 is configured so that the outer peripheral surface 2s (shown in FIG. 3) of the rolling rubber material 2 is continuously irradiated with the laser light Ls at a constant period, whereby the outer periphery of the rotating rubber material 2 is The dimension (for example, outer diameter D1 etc.) of the surface 2s can be continuously measured in the circumferential direction.

  Next, the rubber material evaluation method of this embodiment will be described. In the rubber material evaluation method of this embodiment, first, the wear amount of the rubber material 2 is obtained using the wear tester 3. FIG. 4 is a flowchart showing an example of a processing procedure of the rubber material evaluation method of the present embodiment.

  In the rubber material evaluation method of the present embodiment, a plurality of measurement regions for measuring the wear amount of the rubber material 2 are set in the rubber material 2 (step S1). As shown in FIG. 3, the plurality of measurement regions 15 of the present embodiment are set by dividing the outer peripheral surface 2s of the rubber material 2 in the axial direction. Accordingly, the measurement region 15 is set in a straight line that continues in the circumferential direction of the rubber material 2. The measurement region 15 of the present embodiment includes, for example, a first measurement region 15a to a fifth measurement region 15e.

  The first measurement region 15a is set on one end 2ta of the rubber material 2 in the axial direction. The second measurement region 15b is set between one end 2ta of the rubber material 2 and the equator plane 2c. The third measurement region 15 c is set on the equator plane 2 c of the rubber material 2. The fourth measurement region 15d is set between the equator plane 2c of the rubber material 2 and the other end 2tb of the rubber material 2 in the axial direction. The fifth measurement region 15e is set on the other end 2tb of the rubber material 2. Such a plurality of measurement regions 15 are specified by, for example, coordinate values (dimensions, etc.) of the outer peripheral surface 2s of the rubber material 2 set by the measurement device 12.

  The plurality of measurement regions 15 are not limited to such an embodiment, and can be appropriately set in the range of 2 to 300, for example. The interval W2 between the plurality of measurement regions 15 is set to about 0.1 to 15 mm. The intervals W2 between the plurality of measurement regions 15 are set to be the same, but may be different from each other.

  Next, in the rubber material evaluation method of the present embodiment, the contact condition between the rubber material 2 and the grindstone 4 (hereinafter simply referred to as “contact condition”) so that the wear of each measurement region 15 becomes non-uniform. May be set) (contact condition setting step S2). FIG. 5 is a flowchart showing an example of the processing procedure of the contact condition setting step S2 of the present embodiment. FIG. 6 is a plan view of the rubber material 2 and the grindstone 4.

  In the contact condition setting step S2 of the present embodiment, first, the slip angle θ1 of the rubber material 2 with respect to the grindstone 4 is set (step S21). The slip angle θ1 is a deviation angle between the traveling direction A1 of the rubber material 2 and the rotation direction of the rubber material 2 (that is, the direction of the equator plane 2c of the rubber material 2). The advancing direction A1 of the rubber material 2 is a direction orthogonal to the straight line 20 connecting the center 4c of the grinding wheel 4 and the grounding center 2t of the rubber material 2 (that is, a tangential direction of the disc-shaped grinding wheel 4). By setting such a slip angle θ1, it is possible to cause uneven wear on the outer peripheral surface 2s of the rubber material 2 in the axial direction of the rubber material 2 and make the wear of each measurement region 15 non-uniform.

  The slip angle θ1 is preferably set to 1 to 45 °. If the slip angle θ1 is less than 1 °, the wear of each measurement region 15 may not be sufficiently uneven. On the other hand, when the slip angle θ1 exceeds 45 °, deformation (twist) of the rubber material 2 increases due to the friction between the rubber material 2 and the grindstone surface 4b, and the rubber material 2 may not be sufficiently rubbed. From such a viewpoint, the slip angle θ1 is preferably 3 ° or more and preferably 12 ° or less.

  The slip angle θ1 is preferably adjusted based on the wear characteristics of the rubber material 2 within the above range. That is, it is desirable that the slip angle θ1 is set to be large for the rubber material 2 that is not easily worn. Thereby, the rubber material 2 can be sufficiently worn. On the other hand, it is desirable that the slip angle θ1 is set to be small for the rubber material 2 that is easily worn. Thereby, it is possible to prevent the rubber material 2 from being excessively worn.

  Next, in the contact condition setting step S2 of the present embodiment, a load T1 (not shown) to the grindstone surface 4b of the rubber material 2 is set (step S22). The load T1 can be appropriately set according to the wear characteristics of the rubber material 2. That is, it is desirable that the load T1 is set to be large for the rubber material 2 that is not easily worn. On the other hand, it is desirable that the load T1 is set to be small for the rubber material 2 that is easily worn. Thus, the wear amount of the rubber material 2 can be adjusted by setting the load T1. In addition, load T1 of this embodiment is set in the range of 30-120N, for example.

  Next, as shown in FIG. 4, in the rubber material evaluation method of the present embodiment, the rubber material 2 is pressed against the grindstone 4 and worn based on the contact conditions (step S3). In step S3, first, as shown in FIG. 2, the rubber material 2 is applied to the support portion 9 of the wear tester 3 based on the slip angle θ1 (shown in FIG. 6) set in the contact condition setting step S2. Fixed. Next, in step S3, the rod 10a of the cylinder mechanism 10 is contracted downward, and the rubber material 2 is pressed against the grindstone surface 4b. At this time, the load T1 (not shown) set in the contact condition setting step S2 is set for the rubber material 2. In step S3, the grindstone 4 is rotated about the vertical axis, and the rubber material 2 is freely rolled.

  Thereby, in process S3, the outer peripheral surface 2s of the rubber material 2 can be worn by friction with the grindstone surface 4b. In this embodiment, since the above-mentioned contact conditions (slip angle θ1 and load T) are set, each measurement region 15 of the rubber material 2 can be worn unevenly. In step S3, the rubber material 2 is rolled until a predetermined distance is reached. Thereby, the rubber material 2 can be sufficiently worn. In addition, about the rolling distance of the rubber material 2, it can set suitably, For example, it is about 500-10000m.

  The rotational speed V of the grindstone surface 4b is preferably set to 1 to 40 km / h in order to wear the rubber material 2 effectively. In addition, there exists a possibility that much time may be required for abrasion of the rubber material 2 as the rotational speed V is less than 1 km / h. On the contrary, when the rotational speed V exceeds 40 km / h, the friction between the rubber material 2 and the grindstone surface 4b increases, and the rubber material 2 is likely to jump up, and the wear amount may not be measured accurately. From such a viewpoint, the rotational speed V is preferably 5 km / h or more, and preferably 30 km / h or less.

  Next, in the rubber material evaluation method of this embodiment, the amount of wear in each measurement region 15 (shown in FIG. 3) is measured (step S4). As shown in FIG. 3, the amount of wear in this embodiment is the outer diameter D1 of the outer peripheral surface 2s of the rubber material 2 before wear in each measurement region 15 (hereinafter simply referred to as “outer diameter D1a before wear”). Therefore, the outer diameter D1 of the outer peripheral surface 2s of the rubber material 2 after wear (hereinafter sometimes simply referred to as “the outer diameter D1b after wear”) is reduced. Therefore, it is desirable that the outer diameter D1a before wear of each measurement region 15 is measured by the measuring device 12 prior to the step S3 of wearing the rubber material 2. The outer diameter D1a before wear of each region 15 is stored in the computer 1 (shown in FIG. 1) or the like. In addition, about the measuring method of the outer diameter D1a of each area | region 15 before abrasion, it can implement according to the process procedure same as the measuring method of the outer diameter D1b after abrasion demonstrated below.

  In step S4, first, the laser beam Ls is irradiated on the outer peripheral surface 2s of the rubber material 2 from the irradiation unit 12b (shown in FIG. 3) of the measuring device 12 at a constant cycle. Next, the grindstone 4 is rotated, and the rubber material 2 is rotated at least once with respect to the laser light Ls. Thereby, the outer diameter D1b after wear can be measured at a plurality of measurement positions in the circumferential direction (that is, positions where the laser light Ls is irradiated at a constant period). The outer diameter D1b after such wear is stored in the computer 1 (shown in FIG. 1) or the like.

  FIG. 7 is a graph showing an example of the outer diameter D1a before wear and the outer diameter D1b after wear of each measurement region 15. In step S4, the outer diameter D1b after wear is reduced from the outer diameter D1a before wear in correspondence with each measurement position in the circumferential direction of the measurement region 15 (that is, the position irradiated with the laser beam Ls at a constant period). It is done. Thereby, the wear amount at different positions in the circumferential direction of the measurement region 15 (that is, each measurement position) is obtained. In each measurement region 15, the total amount of wear obtained at different positions in the circumferential direction (that is, each measurement position) is divided by the number of measurement positions. Thereby, the wear amount (average value of the wear amount) Lw of each measurement region 15 is obtained. These series of calculations can be performed by the computer 1. The wear amount Lw in each measurement region 15 is stored in the computer 1.

  As described above, in the contact condition setting step S2 of the present embodiment, the slip angle θ1 of the rubber material 2 with respect to the grindstone 4 is set prior to the step S3 of wearing the rubber material 2, so Wear can be non-uniform. Therefore, in the rubber material evaluation method of the present embodiment, for example, unlike a conventional method in which a plurality of contact conditions are set and the rubber material is worn a plurality of times, a plurality of wear amounts different for each measurement region 15 are set. Can be acquired at once.

  Next, in the rubber material evaluation method of the present embodiment, the wear energy of the rubber material model is measured using the computer 1 (shown in FIG. 1).

  In the present embodiment, first, a rubber material model 16 obtained by modeling the rubber material 2 is input to the computer 1 (step S5). FIG. 8 is a perspective view of the rubber material model 16. The rubber material model 16 is obtained by modeling (discretizing) the rubber material 2 (shown in FIG. 2) with a finite number of elements F (i) (i = 1, 2,...) That can be handled by a numerical analysis method. Is set. As this numerical analysis method, for example, a finite element method, a finite volume method, a difference method, or a boundary element method can be appropriately employed. In this embodiment, the finite element method is adopted.

  As the element F (i) of the rubber material model 16, for example, a tetrahedral solid element, a pentahedral solid element, or a hexahedral solid element is preferably used. Each element F (i) is provided with a plurality of nodes 17. Each element F (i) is defined with numerical data such as an element number, a node 17 number, a coordinate value of the node 17, and material characteristics (for example, density, Young's modulus and / or attenuation coefficient).

  In the rubber material model 16 of the present embodiment, an area 25 corresponding to a plurality of measurement areas 15 (shown in FIG. 3) set in the rubber material 2 is set. The region 25 is set in a straight line that is continuous in the circumferential direction of the rubber material model 16, similarly to the measurement region 15 of the rubber material 2.

  The region 25 of the present embodiment includes a first region 25a corresponding to the first measurement region 15a (shown in FIG. 3), a second region 25b corresponding to the second measurement region 15b (shown in FIG. 3), and a third measurement region. 15c (shown in FIG. 3) corresponding to a third region 25c, a fourth measurement region 15d (shown in FIG. 3) corresponding to a fourth region 25d, and a fifth measurement region 15e (shown in FIG. 3). The fifth area 25e is included. Such a region 25 is specified based on the coordinate value of the node 17 of the element F (i) of the rubber material model 16 or the like. The rubber material model 16 is stored in the computer 1.

  Next, in the rubber material evaluation method of this embodiment, a grindstone model obtained by modeling the grindstone 4 (shown in FIG. 2) is input to the computer 1 (step S6). FIG. 9 is a perspective view of the rubber material model 16 and the grindstone model 18. FIG. 10 is a plan view of FIG.

  The grindstone model 18 of this embodiment is a finite number of elements G (i) (i = 1, 2,...) That can handle the grindstone surface 4b (shown in FIG. 4) of the grindstone 4 by a numerical analysis method. It is set by modeling (discretization). As this numerical analysis method, it is desirable to adopt the finite element method as in the case of the element F (i) of the rubber material model 16 shown in FIG.

  The element G (i) of the grindstone model 18 is composed of a rigid plane element set so as not to be deformable. This element G (i) is provided with a plurality of nodes 19. Furthermore, numerical data such as an element number and a coordinate value of the node 19 are defined for the element G (i). Furthermore, a friction coefficient with each element F (i) of the rubber material model 16 is set for each element G (i) of the grindstone model 18.

  As the grindstone model 18 of this embodiment, what has a smooth surface was illustrated, but it is not necessarily limited to this. For example, the grindstone model 18 may be provided with irregularities such as abrasive grains on the grindstone surface 4b (shown in FIG. 3) as necessary. The grindstone model 18 is stored in the computer 1.

  Next, in the rubber material evaluation method of the present embodiment, the computer 1 brings the rubber material model 16 into contact with the grindstone model 18 based on the contact condition (step S7). That is, in step S7, based on the slip angle θ1 (shown in FIG. 6) and the load T1 set in the contact condition setting step S2, the rubber material model is placed on the grindstone model 18 as shown in FIG. 16 is contacted. As shown in FIG. 10, the slip angle θ <b> 1 is the same as the rubber material 2 shown in FIG. 6, the slip angle of the rubber material model 16 with respect to the grindstone model 18, that is, the traveling direction A <b> 1 of the rubber material model 16. It is a deviation angle from the rotation direction of the rubber material model 16 (that is, the direction of the equatorial plane 16c of the rubber material model 16). The traveling direction A1 is a direction orthogonal to the straight line 23 connecting the center 18c of the grindstone model 18 and the ground center 16s of the rubber material model 16 (that is, a tangential direction of the disc-shaped grindstone model 18).

  Next, in the rubber material evaluation method of the present embodiment, the computer 1 calculates the wear energy of the rubber material model 16 in the region 25 (shown in FIG. 8) corresponding to the measurement region 15 (shown in FIG. 2) ( Wear energy calculation step S8). In the wear energy calculation step S8, the wear energy of the rubber material model 16 is calculated based on the rubber material model 16 rolling the grinding wheel model 18. FIG. 11 is a flowchart showing an example of the processing procedure of the wear energy calculation step S8 of the present embodiment.

  In the wear energy calculation step S8 of the present embodiment, first, boundary conditions for rolling the rubber material model 16 on the grindstone model 18 are defined (step S81). In step S81, the translation speed V1b (shown in FIG. 10) of the grindstone model 18 corresponding to the rotational speed V (shown in FIG. 6) of the grindstone surface 4b is set. Such boundary conditions are stored in the computer 1.

  Next, in the wear energy calculation step S8 of the present embodiment, a state in which the rubber material model 16 rolls the grindstone model 18 is calculated (step S82). In step S82, based on the boundary condition set in step S81 (in this embodiment, the translation speed V1b), a state in which the rubber material model 16 rolls the grindstone model 18 is calculated. In the rubber material model 16 of the present embodiment, the angular velocity corresponding to the velocity V (shown in FIG. 6) is not defined. Thus, in step S83, the rubber material model 16 that freely rolls can be calculated by friction with the rotating grindstone model 18 as in the wear tester 3 shown in FIG.

  In such rolling calculation of the rubber material model 16, a mass matrix, a stiffness matrix, and a damping matrix of each element F (i) are created based on the shape and material characteristics of each element. Furthermore, each of these matrices is combined to create a matrix for the entire system. Then, the computer 1 applies the above-mentioned various conditions to create an equation of motion, and generates these equations for each unit time T (x) (x = 0, 1,...) (For example, every 1 μsec). Perform rolling calculations. Such rolling calculation can be performed using commercially available finite element analysis application software such as LS-DYNA manufactured by LSTC.

  Next, in the wear energy calculation step S8 of the present embodiment, the shear force R and the slip at the node 17 of the rubber material model 16 in the region 25 (shown in FIG. 8) corresponding to the measurement region 15 (shown in FIG. 2). A quantity U is calculated (step S83). The shear force R includes a shear force Rx in the X-axis direction and a shear force Ry in the Y-axis direction.

  FIG. 12A is a side view of the rubber material model 16 that rolls the grindstone model 18. FIG. 12B is a plan view of FIG. The node 17 of the rubber material model 16 that is in contact with the grindstone model 18 at time T (i) moves along the rotation direction (equatorial plane 16c) of the rubber material model 16 after the next time T (i + 1) has elapsed. (First movement position 21). However, in this embodiment, since the slip angle θ1 of the rubber material model 16 with respect to the grindstone model 18 is set, the slip from the second movement position 22 to the first movement position 21 when moving in the direction opposite to the traveling direction A1. SL occurs. From such a viewpoint, the slip amount U of the present embodiment is obtained by the difference between the first movement position 21 and the second movement position 22.

  The slip amount U includes a slip amount Ux in the X-axis direction and a slip amount Uy in the Y-axis direction corresponding to the shearing forces Rx and Ry. The slip amount Ux in the X-axis direction is obtained by the difference (21x−22x) between the X coordinate value 21x of the first movement position 21 and the X coordinate value 22x of the second movement position 22. Further, the slip amount Uy in the Y-axis direction is obtained by a difference (21y−22y) between the Y coordinate value 21y of the first movement position 21 and the Y coordinate value 22y of the second movement position 22. Such shear forces Rx, Ry and slip amounts Ux, Uy are stored in the computer 1.

  Next, in the wear energy calculation step S8 of this embodiment, it is determined whether or not a predetermined rolling end time has elapsed (step S84). In step S84, when it is determined that the rolling end time has elapsed (“Y” in step S84), step S85 for calculating the wear energy of the next rubber material model 16 is performed. On the other hand, when it is determined that the rolling end time has not elapsed ("N" in step S84), the unit time T (x) is advanced by one (step S86), and steps S82 to S84 are performed again. Is done. Thereby, in process S83, while the rubber material model 16 rolls the grindstone model 18, in each node 25 of the rubber material model 16, the shearing forces Rx and Ry and the slip amounts Ux and Uy are: It is calculated in minute time (unit time T (x)) increments.

  Next, in the wear energy calculation step S8, the wear energy of the rubber material model 16 is calculated (step S85). The wear energy of the present embodiment is calculated based on the shear forces Rx (i) and Ry (i) and the slip amounts Ux (i) and Uy (i) stored in the computer 1.

  In the present embodiment, first, at each node 17 (shown in FIG. 8) of each region 25 of the rubber material model 16, while each node 17 is in contact with the grindstone model 18, each shear force Rx (i), Ry. By integrating the values obtained by multiplying (i) and slip amounts Ux (i) and Uy (i) corresponding to the shear forces Rx (i) and Ry (i), the wear energy Ew (i ) Is calculated. The wear energy Ew (i) of the node 17 in each region 25 is integrated every unit time T (x).

  Next, the total of all unit times T (x) of the wear energy Ew (i) of the node 17 in each region 25 (hereinafter, simply referred to as “first total wear energy”) is obtained. In each region 25, the total sum of the first total wear energy obtained at different positions in the circumferential direction (that is, each node 17) (hereinafter, simply referred to as “second total wear energy”) is the region. By dividing by the number of nodes 17 constituting 25, the wear energy (average value of wear energy) Ew of each region 25 is obtained. FIG. 13 is a graph showing an example of the wear energy Ew of each region 25 (first region 25a to fifth region 25e).

  As described above, in this embodiment, the rubber material model 16 is brought into contact with the grindstone model 18 based on the contact condition (that is, the slip angle θ1 of the rubber material model 16 with respect to the grindstone model 18). Yes. For this reason, the slip amounts Ux and Uy of the node 17 can be made different in each region 25 corresponding to the measurement region 15 (shown in FIG. 2). Accordingly, a plurality of different wear energies Ew can be acquired at once for each region 25 corresponding to the measurement region 15.

  Next, in the rubber material evaluation method of the present embodiment, the computer 1 obtains the relationship between the wear amount Lw of the rubber material 2 corresponding to the measurement region 15 and the wear energy Ew of the rubber material model 16 (step S9). . In step S9, the wear amount Lw of each measurement region 15 of the rubber material 2 and the wear energy Ew of each region 25 of the rubber material model 16 are associated with each other so that the wear amount Lw of the rubber material 2 and the wear of the rubber material model 16 are related. A relationship RL with the energy Ew is obtained. FIG. 14 is a graph showing the relationship between the wear amount Lw of the rubber material 2 and the wear energy Ew of the rubber material model 16.

  In the relationship RL between the wear amount Lw of the rubber material 2 and the wear energy Ew of the rubber material model 16, the wear amount Lw with respect to the wear energy Ew can be obtained uniquely. Therefore, the wear performance of the rubber material 2 can be accurately evaluated by using the relationship RL. In the relationship RL, the wear energy Ew under various conditions without performing the wear test using the rubber material 2 and the simulation using the rubber material model 16 for each contact condition necessary for the evaluation of the rubber material 2. The wear amount Lw with respect to or the wear energy Ew with respect to the wear amount Lw can be obtained. Therefore, the relationship RL is useful for efficiently evaluating the wear performance of the rubber material 2.

  In the present embodiment, the wear test using the rubber material 2 (in this embodiment, steps S1 to S4) and the simulation using the rubber material model 16 (in this embodiment, steps S5 to S8) are performed once. As a result, a plurality of wear amounts Lw of the rubber material 2 and a plurality of wear energies Ew of the rubber material model 16 shown in FIG. 14 are obtained. For this reason, in the rubber material evaluation method of this embodiment, it is not necessary to carry out the wear test using the rubber material 2 and the simulation using the rubber material model 16 a plurality of times for different contact conditions. Therefore, in the rubber material evaluation method of this embodiment, the wear performance of the rubber material 2 is shortened using the relationship RL between the wear amount Lw of the rubber material 2 and the wear energy Ew of the rubber material model 16 shown in FIG. Can be evaluated in time.

  Since each wear amount Lw of the rubber material 2 used for setting the relationship RL of the present embodiment is obtained by the average value of each measurement region 15, the conventional method obtained by the average value of the entire rubber material is used. In comparison, measurement error can be reduced. Further, since the wear energy Ew of the rubber material model 16 used for setting the relationship RL of the present embodiment is obtained by the average value of each region 25, the conventional energy value obtained by the average value of the entire rubber material model is obtained. Compared with the method, the calculation error can be reduced. Therefore, in this embodiment, since the correlation coefficient between each plot of the graph of FIG. 14 and the regression curve (that is, the relationship RL) of each plot can be increased, the wear amount Lw of the rubber material 2 and the rubber The relationship RL with the wear energy Ew of the material model 16 can be accurately obtained. Based on such a relationship RL, in this embodiment, the wear performance of the rubber material 2 could be evaluated with high accuracy.

  In the relationship RL, the range in which the wear energy Ew is generated varies depending on the rubber product (for example, a tire) in which the rubber material 2 is used. For this reason, since the wear amount of the rubber product can be obtained from the value (for example, area 24) obtained by integrating the relationship RL in the range of the wear energy Ew generated in the rubber product, the wear performance of the rubber product is accurately evaluated. be able to. In each rubber product, each wear energy Ew is not uniformly generated. For this reason, it is desirable that the area 24 is obtained by weighting each wear energy Ew by the frequency of occurrence of each wear energy Ew. Thereby, the amount of wear of the rubber product can be accurately obtained.

  Next, in the rubber material evaluation method of the present embodiment, the computer 1 determines the rubber material 2 based on the relationship RL between the wear amount Lw of the rubber material 2 and the wear energy Ew of the rubber material model 16 shown in FIG. Wear performance is evaluated (step S10). In step S10, it is determined whether the wear performance of the rubber material 2 is within an allowable range based on the relationship RL. In addition, the allowable range of the wear performance of the rubber material 2 can be set as appropriate.

  In step S10, when the wear performance of the rubber material 2 is within an allowable range (“Y” in step S10), a rubber product using the rubber material 2 is manufactured (step S11). On the other hand, when the wear performance of the rubber material 2 is not within the allowable range ("N" in step S10), the blending of the rubber material 2 is changed (step S12), and the steps S1 to S10 are performed again. As described above, in the simulation method of the present embodiment, since the blending of the rubber material 2 is changed until the wear performance of the rubber material 2 falls within an allowable range, a rubber product having excellent wear performance can be manufactured. .

  As shown in FIG. 3, the rubber material 2 of the present embodiment is exemplified as being formed in a cylindrical shape, but is not limited to such a mode. FIG. 15 is a perspective view showing a rubber material 2 according to another embodiment of the present invention. In this embodiment, the same configurations and methods as those of the previous embodiments are denoted by the same reference numerals, and the description thereof may be omitted.

  In the rubber material 2 of this embodiment, the rubber material 2 formed in a sheet shape is attached to the outer peripheral surface of the base portion 8 formed in a cylindrical shape. Since the rubber material 2 of this embodiment can reduce the amount of rubber used compared to the rubber material 2 (shown in FIG. 3) formed in a cylindrical shape, the manufacturing cost can be reduced. Moreover, the rubber material 2 which has various outer diameter D3 can be formed only by using the base 8 from which a magnitude | size differs. In step S5 for inputting the rubber material model 16, it is desirable that the rubber material 2 and the base portion 8 be modeled by a finite number of elements F (i) shown in FIG.

  The thickness T3 of the rubber material 2 formed in a sheet shape is preferably set to 0.5 to 4.0 mm. The width W3 of the rubber material 2 is desirably in the same range as the width W1 of the rubber material 2 shown in FIG. Further, the outer diameter D3 of the integral body of the rubber material 2 and the base 8 is preferably in the same range as the outer diameter D3 of the rubber material 2 shown in FIG.

  In the step S1 of the embodiments so far, as illustrated in FIG. 3, the aspect in which the measurement region 15 is set in a linear shape continuous in the circumferential direction of the rubber material 2 has been exemplified. It is not limited. For example, the measurement region 15 may be set in a band shape having a width in the axial direction of the rubber material 2. Since such a measurement region 15 can take into account the wear amount in the width direction, the wear performance of the rubber material 2 can be accurately evaluated. The rubber material model 16 preferably has a band-like region 25 corresponding to the measurement region 15. Since such a region 25 can take into account the wear energy in the width direction, the wear performance of the rubber material 2 can be accurately evaluated.

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

  According to the processing procedure shown in FIG. 4, the wear performance of the rubber material was evaluated based on the relationship between the wear amount of the rubber material and the wear energy of the rubber material model (Example). In the rubber material evaluation method of the example, as shown in FIG. 3, a plurality of measurement regions for measuring the wear amount of the rubber material were set in the rubber material. In the contact condition setting step of the example, the slip angle θ1 of the rubber material with respect to the grindstone was set so that the wear in the measurement region was not uniform. Further, the rubber material is worn on the basis of the slip angle θ1, and the wear energy of the rubber material model is measured. The wear amount of the rubber material corresponding to the measurement region shown in FIG. 14 and the wear energy of the rubber material model are measured. Relationship was sought. The wear performance of the rubber material was evaluated based on the relationship between the wear amount of the rubber material shown in FIG. 14 and the wear energy of the rubber material model.

For comparison, based on a plurality of contact conditions including slip angle and load, the rubber material was worn for each contact condition, and the wear energy of the rubber material model was measured (comparative example). In the comparative example, the rubber material was worn substantially uniformly for each of the first contact condition to the fourth contact condition, and one wear amount (average wear amount) was measured. In the comparative example, one wear energy (average wear energy) of the rubber material model was calculated for each of the first contact condition to the fourth contact condition. Further, as shown in FIG. 16, the relationship between the wear amount of the rubber material and the wear energy of the rubber material model was obtained. Then, the wear performance of the rubber material was evaluated based on the relationship between the wear amount of the rubber material shown in FIG. 16 and the wear energy of the rubber material model. The common specifications are as follows.
Abrasion tester: Rubber abrasion tester manufactured by Hiraizumi Yoko Co., Ltd. (model: LAT100)
Measuring device: Ultra-high speed inline profile measuring instrument (LJ-V7080) manufactured by Keyence Corporation
Wheel grain size: 50 (mesh)
Rubber material:
Outer diameter D1: 80mm
Width W1: 18mm
One rolling distance of rubber material: 750m
Wheel surface rotation speed V: 20 km / h
Example:
Rubber material measurement area (rubber material model area): 5 pieces Slip angle θ1: 9 °, load: 75N
Comparative example:
First contact condition:
Slip angle θ1: 3 °, load: 40N
Second contact condition:
Slip angle θ1: 12 °, load: 40N
Third contact condition:
Slip angle θ1: 12 °, load: 75N
Fourth contact condition:
Slip angle θ1: 6 °, load: 100N

  As a result of the test, in the example, the wear test using the rubber material and the simulation using the rubber material model are performed once, so that a plurality of wear amounts Lw of the rubber material and a plurality of wear of the rubber material model are obtained. The wear energy Ew was determined. For this reason, in the Example, the relationship between the amount of wear of the rubber material and the wear energy of the rubber material model could be obtained in a short time.

  On the other hand, in the comparative example, the wear test using the rubber material 2 and the simulation using the rubber material model 16 were performed four times for each of four different contact conditions. For this reason, in the comparative example, much time was required to obtain the relationship between the wear amount of the rubber material and the wear energy of the rubber material model. Therefore, compared with the comparative example, the Example was able to evaluate the abrasion performance of the rubber material in a short time.

  Moreover, in the graph of the Example shown in FIG. 14, the correlation coefficient of each plot and the regression curve of each plot was 0.9997. On the other hand, in the graph of the comparative example shown in FIG. 16, the correlation between each plot and the regression curve of each plot was 0.9885, which was lower than the correlation coefficient of the example. This is because the wear amount Lw is averaged over the entire rubber material and the wear energy Ew is averaged over the entire rubber material model for each of the first contact condition to the fourth contact condition. This is considered to be because the measurement error or calculation error is larger than in the embodiment averaged every time. Therefore, in the embodiment, since the relationship between the wear amount Lw of the rubber material and the wear energy Ew of the rubber material model can be obtained more accurately than in the comparative example, the wear performance of the rubber material can be accurately evaluated. I was able to.

S1 Step of setting a plurality of measurement regions in the rubber material S2 Step of setting contact conditions between the rubber material and the grindstone S3 Step of wearing the rubber material based on the contact conditions S4 Wear amount of each measurement region of the rubber material Step S8 for measuring wear Step S10 for calculating wear energy in the region corresponding to the measurement region S10 Step for evaluating the wear performance of the rubber material

Claims (4)

A method for evaluating the wear performance of a rubber material using a computer,
A step of setting a plurality of measurement regions for measuring the wear amount of the rubber material in the rubber material;
A step of setting contact conditions between the rubber material and a grindstone for wearing the rubber material so that the wear of each measurement region is non-uniform,
A step of pressing the rubber material against the grindstone to wear based on the contact condition;
Measuring the amount of wear in each measurement region,
Inputting to the computer a rubber material model obtained by modeling the rubber material with a finite number of elements;
Inputting to the computer a grindstone model obtained by modeling the grindstone with a finite number of elements;
The computer contacting the rubber material model with the grindstone model based on the contact condition;
The computer calculates the wear energy of the rubber material model in an area corresponding to the measurement area, and the wear amount of the rubber material and the wear of the rubber material model corresponding to the computer in the measurement area A method for evaluating the wear performance of a rubber material, comprising a step of evaluating the wear performance of the rubber material based on a relationship with energy. The rubber material has a cylindrical shape on an outer peripheral surface that rolls on the grinding wheel,
The method for evaluating wear performance of a rubber material according to claim 1, wherein the plurality of measurement regions are set by dividing the outer peripheral surface in the axial direction.   The method for evaluating the wear performance of a rubber material according to claim 2, wherein the wear amount is an average value of wear amounts obtained at different positions in the circumferential direction of the measurement region.   The method for evaluating the wear performance of a rubber material according to claim 2 or 3, wherein the contact condition is a slip angle of the rubber material with respect to the grinding wheel.

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