JP5534586B2 - Rubber testing machine and rubber testing method - Google Patents

Description

  The present invention relates to a rubber testing machine and a rubber testing method, and more particularly to a rubber testing machine and a rubber testing method for performing a vulcanized rubber abrasion test, in particular, a vulcanized rubber abrasion test for automobile tires.

  Conventionally, a lambone tester is known as an apparatus for performing a vulcanized rubber abrasion test (JIS K6264). The Lambourn tester rotates a test piece made of a disc-shaped vulcanized rubber and a disc-shaped grindstone or a simulated road surface at an independently determined number of revolutions while rotating the test piece on the outer circumference of the grindstone or the simulated road surface. The test pieces are worn by being pressed against the surface and slipping each other, and the amount of wear is measured after a certain time.

  Also, in the Lambourn tester, the friction force applied to the test piece when the rubber test piece is rotated so as to have a constant slip rate with respect to the grindstone or the simulated road surface is detected, and each detected friction force and the slip rate are detected. A method of measuring the degree of rubber wear from the friction energy defined based on the above is also known (see Patent Document 1). In this measurement method, both the road surface and rubber are formed so as to be rotatable about an axis, are brought into contact with each other on curved surfaces, and friction energy (= slip distance) obtained approximately from the detected longitudinal force and slip ratio X Friction force) to determine the degree of rubber wear.

  On the other hand, as a rubber testing machine capable of evaluating a more accurate degree of rubber wear, a rubber testing machine that reproduces a behavior when an actual product such as a tire is worn has been proposed ( Patent Document 2). According to this technology, by creating an adhesive state and a slip state of rubber when the rubber and the road surface come into contact with each other, it is possible to more accurately reproduce the wear state when the rubber is actually worn. .

JP-A-11-326169 JP 2009-198276 A (Claims etc.)

  According to the rubber testing machine according to Patent Document 2, the behavior of rubber when an actual product such as a tire is worn is accurately reproduced, and the measured value of the rubber wear degree corresponding to the actual wear result is accurately obtained. It is possible to obtain. However, even in the rubber testing machine of Patent Document 2, since there is a limit to the reproducible tire wear situation, it is possible to evaluate an accurate degree of rubber wear that is closer to the wear situation during actual vehicle travel, and more to actual vehicle travel. The realization of a rubber testing machine capable of reproducing a wear form that is close to the occasion has been demanded.

  Accordingly, an object of the present invention is to solve the above-mentioned problems and to reproduce the behavior of rubber during actual wear with higher accuracy. An object of the present invention is to provide a rubber testing machine and a rubber testing method that can correspond to the results with higher accuracy.

  As a result of intensive studies, the present inventors have found the following points. That is, when an actual product such as a tire is worn, the rubber and the road surface come into contact with each other with a minute angle and leave with a minute angle. On the other hand, in the rubber testing machine according to Patent Document 2, the position of the pseudo road surface is mainly moved in the horizontal direction while moving the position of the rubber test piece in the vertical direction. In this case, since the rubber test piece and the simulated road surface are in contact with each other without a minute angle as in actual wear, such a rubber test machine is limited to the tire wear situation that can be reproduced in this respect. It is thought that there was.

  From this point of view, the present inventor has intensively studied, and as a result, the rubber is actually worn by providing the rubber testing machine with a mechanism for controlling a minute angle at the contact portion when the rubber test piece contacts the road surface. The present invention has been completed by finding that it is possible to reproduce the wear state at the time with higher accuracy.

That is, the present invention is a rubber testing machine for testing a rubber test piece by pressing a rubber test piece having at least a contact portion with the grindstone or the pseudo road surface into a flat shape against the grindstone or the pseudo road surface. ,
An angle control mechanism that changes an angle formed by the pressing direction of the rubber test piece and the surface of the grindstone or the pseudo road surface in accordance with a change in the pressing state of the rubber test piece, and a change amount of the angle in the angle control mechanism. Is between ± 0.1 ° and ± 30 °, and the position of both the rubber test piece and the grindstone or simulated road surface is changed independently of each other to reproduce the phenomenon from the contact of the tire tread block to the kicking out. It is characterized by doing.

Further, the present invention is a rubber test method for testing a rubber test piece by pressing a rubber test piece having at least a contact portion with the grindstone or the pseudo road surface into a flat shape against the grindstone or the pseudo road surface. ,
Along with the change in the pressing state of the rubber test piece, the angle formed by the pressing direction of the rubber test piece and the surface of the grindstone or the pseudo road surface is changed, and the amount of change in the angle is ± 0.1 ° to ± 30 °. In this case, the positions of the rubber test piece and the grindstone or the pseudo road surface are varied independently of each other to reproduce the phenomenon from the contact of the tire tread block to the kicking-out.

  In the present invention, the rubber test piece is pressed against the grindstone or the pseudo road surface, and the relative position of the rubber test piece and the grindstone or the pseudo road surface in the direction perpendicular to the pressing direction is changed. It is preferable to provide adhesion and / or slip to the grindstone or simulated road surface.

  The rubber testing machine of the present invention is an abrasion testing machine that wears the rubber test piece between the grindstone or the simulated road surface and measures the frictional force between the grindstone or simulated road surface and the rubber test piece. It can be suitably used. The rubber test method of the present invention is a wear test in which the rubber test piece is worn between the grindstone or the simulated road surface and the frictional force between the grindstone or the simulated road surface and the rubber test piece is measured. Can be implemented as Furthermore, in this invention, it is preferable to form the contact part with the said rubber test piece of the said grindstone or a pseudo road surface in planar shape.

  According to the present invention, the above configuration makes it possible to more accurately reproduce the behavior of rubber when an actual product such as a tire is worn, thereby measuring the degree of rubber wear and the form of wear to be measured. Thus, it has become possible to realize a rubber testing machine and a rubber testing method that can more accurately correspond to actual wear results.

(A), (b) is a schematic explanatory drawing which shows one structural example of the rubber testing machine of this invention. It is explanatory drawing which shows transition of the contact state between a rubber test piece and a grindstone or a pseudo road surface.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1A is a schematic explanatory diagram of a configuration example of a rubber testing machine according to the present invention. As shown in the figure, the rubber testing machine of the present invention presses a rubber test piece 1 in which at least a contact portion with the road surface 11 is formed flat on a grindstone or a pseudo road surface (hereinafter also simply referred to as “road surface”) 11. Thus, the rubber test piece 1 is tested.

  The rubber testing machine of the present invention is characterized in that it includes an angle control mechanism that changes the angle formed by the pressing direction of the rubber test piece 1 and the surface of the road surface 11 in accordance with the change in the pressing state of the rubber test piece 1. is there. Thereby, as the rubber test piece 1 is pressed against the road surface 11, the angle formed by the surface of the rubber test piece 1 and the surface of the road surface 11 is changed, and the rubber test piece 1 and the pseudo road surface 11 are changed. The contact can be made with a minute angle as in actual wear. Therefore, according to the rubber testing machine of the present invention, it is possible to test the rubber test piece 1 in a state where the wear state when the rubber is actually worn is reproduced with higher accuracy.

  In the present invention, as the angle control mechanism, as long as the angle formed by the pressing direction of the rubber test piece 1 and the surface of the road surface 11 can be changed with the change in the pressing state of the rubber test piece 1, The specific configuration is not particularly limited. For example, an angle control mechanism composed of a fulcrum and an actuator described later can be suitably used.

  In the rubber testing machine shown in the figure, a grindstone or a pseudo road surface 11 is configured to be reciprocally movable in a plane along a guide rail 12, and the rubber test piece 1 is fixed by a jig (holder) 13 to be guided. It is configured to reciprocate in the direction perpendicular to the road surface 11 along the rail 14. Thereby, since the position of both the rubber test piece 1 and the road surface 11 can be changed independently of each other, the rubber test piece 1 is pressed against the road surface 11 and the rubber test piece 1 and the road surface 11 are pressed in the pressing direction. It is possible to independently control the relative position change in the orthogonal direction.

  In the illustrated rubber testing machine, the guide rail 12 for moving the road surface 11 is supported by the fulcrum 15 and the actuator 16, and the relative angle between the rubber test piece 1 and the road surface 11 is arbitrarily changed by the operation of the actuator 16. It is configured to By providing such an angle control mechanism including the fulcrum 15 and the actuator 16 in the rubber testing machine, the pressing direction of the rubber test piece 1 and the surface of the road surface 11 are made according to the change in the pressing state of the rubber test piece 1. The angle α can be changed.

  In the rubber testing machine according to the present invention, the road surface 11 and the road surface 11 are reproduced so as to reproduce the operation when the tire tread block is stepped on the road surface and then kicked out (grounding to kicking out). Both movement, position and relative angle of the rubber specimen 1 can be controlled and varied independently of each other. Here, in the rubber testing machine shown in FIG. 1 (a), the guide rail 12 for moving the road surface 11 is supported by the fulcrum 15 and the actuator 16, and the relative angle between the rubber test piece 1 and the road surface 11 is controlled. However, in the present invention, the relative angle may be controlled by arranging a fulcrum 15 and an actuator 16 on the guide rail 14 side for moving the rubber test piece 1 as shown in FIG.

  The amount of change in the angle α in the angle control mechanism of the rubber testing machine of the present invention, that is, the difference between the maximum value and the minimum value of the angle α formed by the pressing direction of the rubber test piece 1 and the surface of the road surface 11 is For example, it can be in the range of ± 0.1 ° to ± 30 ° (see FIG. 2). By making the amount of change in this range, when the rubber actually wears, especially when the tread block of the tire steps into the road surface and kicks it out, it reproduces the minute angle range that occurs at the contact portion between the rubber and the road surface It becomes possible to do.

  In the present invention, in particular, the rubber test piece 1 is pressed against the road surface 11 by changing the relative position of the rubber test piece 1 and the road surface 11 in the direction perpendicular to the pressing direction. It is preferable to provide adhesion and / or slip. By applying adhesion and / or slip to the rubber test piece 1, the behavior of the rubber test piece 1 at the time of wear can be reproduced in a state closer to the actual condition including the adhesion state and the slip state. Therefore, according to such a rubber testing machine, for example, a rubber abrasion test (or rubber friction test, hereinafter referred to as “abrasion test” and “friction test” in the present invention) that can accurately trace the wear behavior of the tread rubber during actual vehicle running. This makes it possible to predict the degree of rubber wear (amount of wear) of the tread rubber in an actual vehicle with high accuracy.

  Here, the behavior of the rubber test piece 1 when the test of the rubber test piece 1 is performed using the rubber testing machine shown in FIG. 1 will be described. FIG. 2 is an explanatory diagram showing an example of the transition of the contact state between the rubber test piece 1 and the road surface 11. In the illustrated example, the rubber test piece 1 is pressed against the road surface 11 to move the position downward in the vertical direction, and the relative angle between the rubber test piece 1 and the road surface 11 is changed, and the position of the road surface 11 is horizontal. Move to the right. That is, immediately after the rubber test piece 1 moves downward in the vertical direction and comes into contact with the road surface 11, the rubber test piece 1 adheres to the road surface 11 while shearing and follows the movement of the road surface 11 (in the drawing). (B), (c)). Thereafter, when the limit of the shear deformation of the rubber test piece 1 is exceeded, slip occurs together with adhesion between the rubber test piece 1 and the road surface 11 ((d) in the figure). Further, when the moving direction of the rubber test piece 1 is changed to the upper side in the vertical direction, the rubber test piece 1 and the road surface 11 are not sticked and only slip ((e) in the figure). Thus, the rubber test piece 1 and the road surface 11 are made to change independently by mutually changing the positions of both the rubber test piece 1 and the road surface 11 while changing the relative angle between the rubber test piece 1 and the road surface 11. The rubber test piece 1 can be sheared and deformed to reproduce the minute angle formed, thereby giving the rubber test piece 1 adhesion and / or slip. In this case, although not shown, only the rubber test piece 1 is moved with respect to the road surface 11 to give the rubber test piece 1 adhesion and / or slip to the road surface 11 and to cause shear deformation. Is possible.

  In the rubber abrasion test by the rubber testing machine of the present invention, specifically, the rubber test piece 1 is worn between the road surface 11 and the frictional force between the road surface 11 and the rubber test piece 1 is measured. Can be done. In the present invention, not only the wear amount can be measured, but also the relative angle between the rubber test piece 1 and the road surface 11 when the rubber test piece 1 is worn as described above, and more particularly, the adhesion It is also possible to reproduce the state and the slip state, and the slip distance generated between the rubber test piece 1 and the road surface 11 at the time of wear with a slip ratio that is the same as or close to that of the tire, as in the conventional method, is not constant. Since each frictional force can be directly measured, the wear energy defined by the slip distance × frictional force can be directly calculated. Further, since the rubber test piece 1 can be grounded and worn against the road surface 11 by the same mechanism as that of the tire, it is possible to significantly improve the actual vehicle predictability as a result.

  In the rubber testing machine of the present invention, the grindstone or the simulated road surface 11 is formed of any material and surface properties such as various asphalts, concrete, sandpaper, wire nets, etc. according to the test conditions such as the intended road surface conditions. Is possible. In particular, it is preferable that at least a portion including a contact portion with the rubber test piece 1 is formed so as to be detachable so that it can be exchanged according to test conditions. Furthermore, in consideration of the temperature condition of the road surface, it is also preferable to form the contact portion of the road surface 11 with the rubber test piece 1 so that the temperature can be controlled.

  Moreover, as shown in the drawing, it is preferable that at least a contact portion of the grindstone or the pseudo road surface 11 with the rubber test piece 1 is formed in a flat shape. The shape of the contact surface is different between the case where the rubber is in contact with a flat surface like the actual road surface and the case where the rubber test piece is in contact with the curved road surface like a Lambourn test machine, but the road surface is flat. This eliminates the influence of the curvature and makes it possible to reproduce the same state as when an actual rubber product contacts the road surface. Further, in the present invention, unlike the conventional method, there is no particular limitation on the shape of the ground contact portion with the road surface 11 of the rubber test piece 1. It is also possible to easily correspond to the elliptical shape of the ground.

  Further, although not shown in the drawings, in the rubber testing machine of the present invention, a load cell (for load detection) for measuring a vertical load applied to the rubber test piece 1 is provided on the guide rail 12 for moving the road surface 11. A load cell (for detecting the frictional force) for measuring the frictional force applied to the rubber test piece 1 may be disposed on each of the guide rails 14 for moving the rubber test piece 1. Furthermore, as an observation means capable of observing the contact portion between the road surface 11 and the rubber test piece 1, a camera for observing the behavior of the rubber test piece 1 such as slip on the road surface 11, and the road surface of the rubber test piece 1. It is also possible to provide a three-component force sensor or the like for measuring a frictional force or a load applied to a contact portion with 11 at an appropriate place. Furthermore, in the rubber testing machine of the present invention, a laser or the like can be arranged as a measuring means for measuring the wear shape of the contact portion with the road surface 11 of the rubber test piece 1. When the test is performed, a wear powder removing means for removing the wear powder can be provided.

1 Rubber test piece 11 Grinding wheel or simulated road surface 12, 14 Guide rail 13 Jig (holder)
15 fulcrum 16 actuator

Claims (8)

A rubber testing machine for testing a rubber test piece by pressing a rubber test piece having at least a contact portion with the grindstone or the pseudo road surface into a flat shape against a grindstone or a pseudo road surface,
An angle control mechanism that changes an angle formed by the pressing direction of the rubber test piece and the surface of the grindstone or the pseudo road surface in accordance with a change in the pressing state of the rubber test piece, and a change amount of the angle in the angle control mechanism. Is between ± 0.1 ° and ± 30 °, and the position of both the rubber test piece and the grindstone or simulated road surface is changed independently of each other to reproduce the phenomenon from the contact of the tire tread block to the kicking out. A rubber testing machine characterized by   Along with the pressing of the rubber test piece against the grindstone or the pseudo road surface, the relative position of the rubber test piece and the grindstone or the pseudo road surface in the direction perpendicular to the pressing direction is changed, and the rubber test piece is moved to the grindstone or the pseudo road surface. 2. The rubber testing machine according to claim 1, which provides adhesion and / or slip to the road surface. The rubber according to claim 1 or 2 , wherein the rubber test piece is worn between the grindstone or the simulated road surface and the friction test force is measured between the grindstone or the simulated road surface and the rubber test piece. testing machine. The rubber testing machine according to any one of claims 1 to 3 , wherein a contact portion of the grindstone or the pseudo road surface with the rubber test piece is formed in a flat shape. A rubber test method for testing a rubber test piece by pressing a rubber test piece in which at least a contact portion with the grindstone or the pseudo road surface is formed into a flat shape against a grindstone or a pseudo road surface,
Along with the change in the pressing state of the rubber test piece, the angle formed by the pressing direction of the rubber test piece and the surface of the grindstone or the pseudo road surface is changed, and the amount of change in the angle is ± 0.1 ° to ± 30 °. The rubber test method is characterized in that the positions of both the rubber test piece and the grindstone or the pseudo road surface are varied independently of each other to reproduce the phenomenon from the contact of the tire tread block to the kicking-out . Along with the pressing of the rubber test piece against the grindstone or the pseudo road surface, the relative position of the rubber test piece and the grindstone or the pseudo road surface in the direction perpendicular to the pressing direction is changed, and the rubber test piece is moved to the grindstone or the pseudo road surface. 6. The rubber test method according to claim 5 , wherein adhesion and / or slip to the road surface is given. The rubber test method according to claim 5 or 6 , wherein the rubber test piece is worn between the grindstone or the simulated road surface, and the frictional force between the grindstone or the simulated road surface and the rubber test piece is measured. The rubber test method according to claim 5 , wherein a contact portion of the grindstone or the pseudo road surface with the rubber test piece is formed in a flat shape.

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