JP4343791B2 - Vulcanized rubber wear test method - Google Patents

Description

  The present invention relates to a vulcanized rubber abrasion test method, and more particularly to a vulcanized rubber abrasion test method suitable for a flexible rubber (for example, an elastic modulus at 300% elongation of 7 MPa (room temperature) or less).

Conventionally, in order to evaluate the wear of a vulcanized rubber, it has been generally performed to evaluate the wear using a lambone wear tester (see Patent Documents 1 and 2).
JP 2004-101484 A JP-A-8-233716

However, when a rubber test is performed using a conventional abrasion tester, the following problems occur.
(1) When a grindstone or a safety walk is used as a friction member (road surface), rubber wear powder adheres to these surfaces, and the friction member surface changes during measurement. End up.
(2) Wearing a soft rubber with an anti-adhesive agent such as sand or talc that prevents the rubber from adhering can prevent the rubber from adhering to the friction member. This causes variations in the amount of wear.

  In view of the above facts, an object of the present invention is to provide a vulcanized rubber wear test method having excellent reproducibility.

  The invention according to claim 1 is a vulcanized rubber wear test method in which a test piece made of vulcanized rubber and a friction member are pressed while rotating to wear the vulcanized rubber. It is characterized in that a friction member is used in which only protrusions that taper toward the outer side in the radial direction are arranged on the outer peripheral surface that comes into contact.

  In the wear test method according to the first aspect, the test piece made of vulcanized rubber and the friction member are pressed while rotating to wear the vulcanized rubber.

  Since only the protrusions that taper toward the outer side in the radial direction are disposed on the outer peripheral surface of the friction member, the worn rubber powder is difficult to catch on the outer peripheral surface, and even if it is caught, it is easy to remove. Therefore, the outer peripheral surface of the friction member hardly changes during the test, and a test with excellent reproducibility can be performed.

  The invention according to claim 2 is the vulcanized rubber wear test method according to claim 1, wherein an adhesion inhibitor for preventing adhesion of rubber is not adhered to the vulcanized rubber and the friction member. It is characterized by that.

  Since the wear test is performed without using an adhesion preventive agent, there is no problem with the prior art that the amount of wear varies when the adhesion preventive agent sinks into the test piece.

  According to a third aspect of the present invention, in the wear test method for a vulcanized rubber according to the first or second aspect, the friction member includes a plurality of chevron-shaped protrusions extending in the axial direction in the circumferential direction. It is characterized by being.

  The vulcanized rubber can be worn by arranging a plurality of angle-shaped protrusions extending along the axial direction on the outer peripheral surface of the friction member.

  Note that by arranging a plurality of chevron-shaped protrusions in the circumferential direction, the outer peripheral portion of the friction member has a triangular wave shape, a sine wave shape or the like.

  According to a fourth aspect of the present invention, in the wear test method for vulcanized rubber according to the first or second aspect, the friction member includes a plurality of quadrangular pyramid-shaped protrusions arranged in the axial direction and the circumferential direction. It is characterized by that.

  The vulcanized rubber can be worn by arranging a plurality of quadrangular pyramidal protrusions in the axial direction and circumferential direction on the outer peripheral surface of the friction member.

  According to a fifth aspect of the present invention, in the vulcanized rubber wear test method according to the first or second aspect, the friction member includes a plurality of hemispherical protrusions arranged in the axial direction and the circumferential direction. It is characterized by that.

  The vulcanized rubber can be worn by arranging a plurality of hemispherical protrusions on the outer peripheral surface of the friction member in the axial direction and the circumferential direction.

  The invention according to claim 6 is the vulcanized rubber wear test method according to any one of claims 1 to 5, wherein the protrusion has a maximum height in a range of 0.3 to 10 mm, The minimum width is in the range of 0.3 to 10 mm.

  When the maximum height of the protrusion is less than 0.3 mm, the input to the rubber is small and it is difficult to wear.

  When the maximum height of the protrusion exceeds 10 mm, the protrusion apex angle becomes too acute, and the test piece is input in the form of a crack (scratching), and the wear form is greatly different.

  When the minimum width of the protrusion is less than 0.3 mm, the protrusion is too fine, and the input to the rubber is small and is difficult to wear.

  When the minimum width of the protrusion exceeds 10 mm, the width between the protrusion vertices becomes too large, and there is a possibility that the test piece is not contacted.

  Therefore, the protrusion preferably has a maximum height in the range of 0.3 to 10 mm and a minimum width in the range of 0.3 to 10 mm.

  According to a seventh aspect of the present invention, in the friction method for a vulcanized rubber according to any one of the first to sixth aspects, the friction member has a contact surface with the vulcanized rubber made of a metal or ceramic. , And at least one of synthetic resins.

  The reason why the contact surface of the friction member with the vulcanized rubber is formed of at least one of metal, ceramic and synthetic resin is to suppress the friction member from being worn as much as possible. When the safety walk is used, the friction member is worn and cannot be reused.

  As described above, according to the vulcanized rubber abrasion test method of the present invention, there is an excellent effect that the vulcanized rubber abrasion test having excellent reproducibility can be performed.

[First Embodiment]
Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a side view of a wear tester 10 for realizing the vulcanized rubber wear and wear test method of the present invention.

  The abrasion testing machine 10 includes a polishing drum 12 that is rotated by a driving device (not shown).

  A mounting portion 16 for mounting the test piece 14 is provided at a position facing the polishing drum 12.

  The attachment portion 16 is brought into contact with and separated from the rotational axis of the polishing drum 12 via the piston rod 20 by the pneumatic cylinder 18, and when the attachment portion 16 approaches the polishing drum 12, the outer peripheral surface of the test piece 14 is arbitrary. It is pressed against the outer peripheral surface of the polishing drum 12 at a predetermined pressure.

  Note that the mounting portion 16 is also rotated by a driving device (not shown).

  As shown in FIG. 2, the polishing drum 12 of this embodiment is formed in a cylindrical shape, and a plurality of protrusions 22 extending in the axial direction are arranged on the outer peripheral surface at intervals in the circumferential direction.

  As the material of the polishing drum 12, metals such as iron, aluminum, and stainless steel, ceramics, synthetic resins, and the like can be used.

  The material of the protrusion 22 can be the same as the material of the polishing drum 12.

  The protrusion 22 of the present embodiment has a triangular shape when viewed in a cross section perpendicular to the axis of the polishing drum 12.

  Here, the triangular protrusions 22 preferably have a height H in the range of 0.3 to 10 mm and a bottom width W in the range of 0.3 to 10 mm.

  Further, the circumferential arrangement of the protrusions 22 may be arranged with a gap as shown in FIG. 2, but may be arranged adjacent to each other without a gap as shown in FIG.

  Further, the protrusion 22 is not limited to a triangular cross section, but a quadrangular pyramid (pyramid shape) as shown in FIGS. 4 and 5 and a hemispherical shape as shown in FIGS. May be formed).

  The protrusions 22 shown in FIGS. 4 to 7 may be arranged in a grid pattern in the drum axis direction and in the circumferential direction, or may be arranged in a staggered pattern.

Further, the outer peripheral surface of the polishing drum 12 may be sinusoidal when viewed from the side.
(Function)
Next, a test method using this wear tester 10 will be described.

  First, a rubber test piece (for example, an elastic modulus at 300% elongation of 7 MPa (room temperature) or less) 14 is attached to the attachment portion 16, and the pneumatic cylinder 18 is operated to attach the rubber test piece 14 to the polishing drum 12 at a predetermined pressure. Then, the test piece 14 and the polishing drum 12 are rotated.

  At this time, the rubber adhesion preventing agent or the like used in the conventional test is not attached to the test piece 14 and the polishing drum 12 at all.

  According to the abrasion tester of this embodiment, the rubber test piece 14 and the polishing drum 12 are brought into contact without using a rubber adhesion preventing agent or the like, so that the rubber adhesion preventing agent or the like is absorbed into the rubber test piece 14. There is no problem with the prior art that the amount of wear varies.

  Further, since the protrusion 22 has a tapered shape (in other words, the groove portion between the protrusions is wide toward the outside in the radial direction), it is difficult for rubber abrasion powder to be caught on the drum surface, and it was caught. Therefore, the drum outer peripheral surface does not change during measurement, and measurement with excellent reproducibility can be performed.

Hereinafter, an example of preferable test conditions when a flexible rubber test is performed will be described.
Test load: 1.0-10.0 kgf
Drum (road surface) rotation speed: 50 to 250 rpm
Rubber test piece rotation speed: 50-250 rpm
Test time: 10 to 120 sec
The test load, drum rotation speed, rubber test piece rotation speed, and test time vary depending on the rubber test piece.
(Test example)
In order to confirm the effect of the present invention, the wear and wear test method of the present invention, the conventional wear and wear test method, and the actual vehicle wear test were compared.
(A) Test conditions by abrasion tester Drum (road surface) material: Iron protrusion: Triangular protrusion extending in the axial direction (see FIG. 2)
479 projections are arranged for a height of 1.0 mm, a bottom width of 1.0 mm, a spacing of 1.0 mm, and a drum circumference of 958 mm.
Test load: 3.5kgf
Drum rotation speed: 200rpm
Rubber test piece rotation speed: 125rpm
Test time 30 sec
Non-adhesive agent test piece: Six samples were used. The amounts of rubber, sulfur, vulcanization accelerator, and carbon (parts by weight) of the sample are as described in Table 1 below.
(B) Test conditions based on actual vehicle test Vehicle: Taxi Traveling distance: 5000 km
Tire size: 185 / 70R14
(C) Evaluation method

なお、表１内の試験結果の数値は、摩耗量（ｇ）のＩｎｄｅｘ値である。

In addition, the numerical value of the test result in Table 1 is the index value of the amount of wear (g).

Abrasion amount (g) = initial sample weight (g) −post-measurement sample weight (g)
When the result of the test method of the present invention and the result of the actual vehicle wear resistance test were plotted, a correlation coefficient R = 0.93 was obtained.

  As a result, according to the wear test method of the present invention, the wear of rubber by an actual vehicle can be accurately predicted from the result of the wear tester.

  In addition, in the conventional test method, since the anti-adhesive agent was absorbed into the test piece, a quantitative evaluation result could not be obtained, and a correlation with the actual vehicle result could not be obtained.

It is a side view of an abrasion tester. (A) is a side view of a polishing drum, (B) is a perspective view which shows the outer peripheral surface of a polishing drum. (A) is a side view of a polishing drum, (B) is a perspective view which shows the outer peripheral surface of a polishing drum. (A) is a side view of a polishing drum, (B) is a perspective view which shows the outer peripheral surface of a polishing drum. (A) is a side view of a polishing drum, (B) is a perspective view which shows the outer peripheral surface of a polishing drum. (A) is a side view of a polishing drum, (B) is a perspective view which shows the outer peripheral surface of a polishing drum. (A) is a side view of a polishing drum, (B) is a perspective view which shows the outer peripheral surface of a polishing drum.

Explanation of symbols

10 Abrasion Tester 12 Abrasive Drum (Friction Member)
22 Protrusions

Claims (7)

A vulcanized rubber wear test method in which a test piece made of vulcanized rubber and a friction member are pressed while rotating to wear the vulcanized rubber,
A vulcanized rubber wear test method, characterized in that a friction member in which only protrusions having a taper shape toward the outer side in the radial direction are arranged on an outer peripheral surface in contact with the vulcanized rubber. The vulcanized rubber abrasion test method according to claim 1, wherein an adhesion preventing agent for preventing adhesion of rubber is not adhered to the vulcanized rubber and the friction member. 3. The vulcanized rubber wear test method according to claim 1, wherein the friction member includes a plurality of chevron-shaped protrusions extending in the axial direction in the circumferential direction. 4. 3. The vulcanized rubber wear test method according to claim 1, wherein the friction member includes a plurality of quadrangular pyramid-shaped protrusions arranged in an axial direction and a circumferential direction. 4. 3. The vulcanized rubber wear test method according to claim 1, wherein the friction member includes a plurality of hemispherical protrusions arranged in an axial direction and a circumferential direction. 4. 6. The protrusion according to claim 1, wherein the protrusion has a maximum height in a range of 0.3 to 10 mm and a minimum width in a range of 0.3 to 10 mm. Test method for wear of vulcanized rubber. 7. The friction member according to claim 1, wherein a contact surface with the vulcanized rubber is formed of at least one of metal, ceramic, and synthetic resin. The method for rubbing vulcanized rubber as described in the item.

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