JP3636855B2 - Elastic body wear test method - Google Patents

Description

正確に設定することが、試験精度の向上のために必要であり、これがためには、試験片の周長を正確に求めることが必須となるところ、従来のこの摩耗試験では、試験片の理論直径、すなわち、試験片を型加硫によって製造する場合にはモールド寸法を、また切断によって製造する場合には、切断刃の寸法をそれぞれ用いて試験片の周長を算出し、そしてこの周長から試験片の周速を演算していたことから、試験片に加硫戻りが生じたり、切断刃の切れ味が悪くなったりしたとき等には、試験片の理論直径と、試験片の実際の静的直径との間に無視することのできない変動が生じ、しかも、摩耗試験に当って、試験片を、摩耗試験装置の試験片取付部で厚み方向に挟持することによる、試験片の半径方向の弾性変形および、試験に際して、試験片周面を砥石周面に所定の力で押付けることによる試験片の弾性変形が不可避であって、これらのこともまた試験片の理論直径と、試験時の実際の直径との間の直径変動の原因となっているため、理論直径に基づいて設定した試験片周速と、試験中のそれの実際の周速との間に大きな隔たりが生じることがしばしばあり、それ故に、摩耗試験の実施に際して所期した通りのスリップ率を実現し得ないことが多く、このことが、とくには、１〜５％程度の小さなスリップ率を設定して摩耗試験を行う場合の、スリップ率の設定精度、ひいては、摩耗試験精度に大きな影響を及ぼすという問題があった。
【０００４】
この発明は、従来技術の抱えるこのような問題点を有利に解決するものであり、実際の試験条件を付与した状態の下での試験片の周長を試験片毎に測定し、この測定結果に基づいてスリップ率の設定を行うことで、スリップ率の大小にかかわらず、それの設定精度を大きく高め、試験精度を効果的に向上させることができる弾性体の摩耗試験方法を提供するものである。
【０００５】
【課題を解決するための手段】
この発明の、弾性体の摩耗試験方法は、回転砥石の周面にホルダーで保持した円板状の弾性体試験片の周面を押圧するとともに、回転砥石および弾性体試験片のそれぞれを、相互に平行な回転軸線の周りで、異なる周速で回転駆動して弾性体試験片を摩耗させる摩耗試験の開始に先だち、ホルダーで保持して回転自在とした弾性体試験片を、試験時と同等の力で回転砥石に押圧するとともに、その回転砥石を試験時と同等の周速で回転させ、これによって、弾性体試験片を、それの、砥石に対する摩擦力によってその砥石周速と等しい周速で駆動し、弾性体試験片の少なくとも一回転毎に発生するパルスと、既知の周長を有する砥石の、所定回転角度毎に発生するパルスとを対比して、砥石側から発生するパルス数に基づいて弾性体試験片の試験時の周長を求め、この周長から、弾性体試験片の試験時の周速を算出するものである。
【０００６】
この試験方法では、たとえば、周長が未知の弾性体試験片の１回転につき１のパルスが発生するものとし、また、周長が既知の弾性体試験片の１回転につき６０００のパルスが発生するものとして、ホルダーで保持したその弾性体試験片を、試験条件と同一の条件で砥石周面に押圧するとともに、試験時の砥石周速と等しい周速でその試験片を回転駆動した場合に、これもたとえば、砥石直径よりはるかに小さい直径を有する試験片の１回転当りの、砥石側の発生パルスをカウントして、または、これとは逆に、砥石の１回転当りの、試験片側の発生パルスをカウントして、パルス間隔に対応する周長が予め既知の砥石側発生パルスの数に基づいて試験片の周長を算出することで、試験時と同一の条件の付与下での試験片の周長を、簡単にかつ、高い精度をもって測定することができるので、この周長をもって試験時の、所要の試験片周速を算出することにより、スリップ率の設定精度を十分に高め、摩耗試験精度を大きく向上させることができる。
【０００７】
この発明に係る方法の実施に用いることができる、弾性体の摩耗試験装置は、回転砥石を装着する砥石駆動軸を設け、また、この砥石駆動軸と平行に延在し、砥石周面と対向する位置に円板状の弾性体試験片を保持するホルダーを有するとともに、中間部にクラッチを有する試験片駆動軸を設け、そして、その試験片駆動軸側に、弾性体試験片の少なくとも一回転毎にパルスを発生するパルス発生手段を設け、さらに、砥石駆動軸側に、回転砥石の所定回転角度毎にパルスを発生する他のパルス発生手段を設けたものである。
【０００８】
このような試験装置では、実際の摩耗試験の開始に先だって、弾性体試験片をホルダーにて保持するとともに、クラッチの解除下にてその試験片の自由な回転を許容し、また、その弾性体試験片の周面を砥石周面に、試験時の押圧力と同等の力で押圧するとともに、砥石を、試験時の周速にて回転させて、弾性体試験片を砥石周速と等しい周速で連れ回り回転させ、たとえば、試験片が１回転する間に、砥石側から発生されるパルス数をカウントして、パルス間隔と対応する既知の周長とパルス数とを積算することによって、試験条件と同一の条件の下での試験片周長を、簡単にかつ正確に求めることができる。
【０００９】
なおこの場合の周長測定精度は、砥石の１回転についての発生パルス数を多くすることで一層高めることができ、また、同一の試験片についての周長測定を、たとえば２０〜３０回行ってそれを平均化することで、測定誤差等の影響を十分小ならしめることができる。
【００１０】
従って、その後における摩耗試験の開始に際しては、上述のようにして求めた試験片周長に基づいて算出した所要の周速で試験片を回転駆動することにより、所期した通りのスリップ率を正確に付与することができ、摩耗試験精度を大きく向上させることができる。
【００１１】
【発明の実施の形態】
以下にこの発明の実施の形態を図面に示すところに基づいて説明する。
図１は、この発明に係る方法の実施に用いることができる装置をその要部について示す正面図および側面図であり、図２はそれの平面図である。
図中１は、既知の直径を有する回転砥石を、２は、この回転砥石１を一端部に取付けた砥石駆動軸をそれぞれ示し、この砥石駆動軸は、その他端を、図示しないサーボモータその他の回転駆動手段に連結される。
【００１２】
ここでは、試験片駆動軸３を砥石駆動軸２と平行に延在させて配設し、この試験片駆動軸３の一方の端部に、円板状の弾性体試験片４を保持するホルダー５を設け、その他端を、上記回転駆動手段とは別個の、図示しないサーボモータその回転駆動手段に連結するとともに、その中間部にクラッチ６を設ける。
【００１３】
ここで、ホルダー５は、駆動軸側に設けた受けパッド５ａと、たとえば、試験片駆動軸３の直下位置に配置したシリンダ７によって、受けパッド５ａに対して進退変位されるクランプパッド５ｂからなり、これらの両パッド５ａ，５ｂは、それらの間に配置した弾性体試験片４をそれの厚み方向から所要の力で挟持して、その試験片周面を、砥石１の周面に対向させて位置させる。従ってここでは、試験片駆動軸３の回転作動に基づき、試験片４が、両パッド５ａ，５ｂとともに、その駆動軸３と等速で回転する。
【００１４】
またここで、前記クラッチ６は、試験片駆動軸３、より直接的にはホルダー５の、回動駆動手段に対する断接を司るべく機能し、そのクラッチ６を解除することで、ホルダー５およぴ試験片４の自由な回転を許容する。
【００１５】
ところで、このような試験片駆動軸３は、図２に示すところから明らかなように、それを可動ベース８上に取付け、そしてこの可動ベース８を、たとえば、固定ベース９上に敷設したガイドレール１０の作用下で、試験片駆動軸３の軸線と直交する方向に進退変位可能ならしめることにより、砥石駆動軸２との平行状態を維持したまま、それに接近し、また離隔変位することができる。
【００１６】
さらにこの装置では、ホルダー５のクランプパッド５ｂの回転軸１１を、それを軸受け支持するハウジング１２に貫通させて設け、そしてこの回転軸１１の端部分に、周方向の適宜個所、図では一個所だけに切欠部を有する反射円板１３を締付固定し、また、ハウジング１２に、反射円板１３に対する発光部および、その反射円板１３からの反射光の受光部を具える光センサ１４を取付けて、これらの反射円板１３と光センサ１４とで、試験片４の１回転につき、１のパルスを発生するパルス発生手段を構成する。
【００１７】
このパルス発生手段は、反射円板１３、ひいては、試験片４が１回転して、光センサ１４の発光部から照射された光線が、反射円板１３に設けた切欠部１３ａに通過することによって、センサー受光部への反射光の入射が無くなる度毎に１個のパルスを発生すべく機能する。
【００１８】
この一方で、回転砥石側には、たとえばサーボモータとすることができるその回転駆動手段との関連において、砥石１の１回転当り、たとえば６０００個もしくはそれ以上のパルスを発生する、図示しない既知のパルス発生手段を設ける。
【００１９】
以上のように構成してなる装置を用いて、弾性体試験片の摩耗試験を行う場合には、その試験の開始に先だって、ホルダー５にその弾性試験片４を保持するとともに、試験片駆動軸３のクラッチ６を解除して、その試験片駆動軸３、直接的には可動ベース８を、図示しない進退駆動手段の作用下で、砥石駆動軸側へ進出変位させ、これにより、弾性体試験片４の周面を、砥石１の周面に摩耗試験時と同等の力で押圧し、併せて、その砥石１を、試験時の周速と等しい速度で回転させて、弾性体試験片４を、砥石１に対する押付け摩擦力によって、それに、砥石周速と等しい周速で連れ回りさせる。
そして、このような連れ回り回転中に、砥石側および試験片側のそれぞれから発生されるパルスをともにカウントし、前述したように、パルス間隔と対応する周長が既知の砥石側の発生パルスに基づいて、試験条件と同一の条件下での試験片周長を算出する。
【００２０】
従って、その後における摩耗試験の開始に際しては、上述のようにして求めた試験片周長に基づいて、所要のスリップ率に応じた試験片周速を求めることで、スリップ率を、それの大小にかかわらず、高い精度で設定することができる。
【００２１】
ところで、このスリップ率の設定は、摩耗試験に当って、試験片駆動軸３のクラッチ６を接続状態とするとともに、その駆動軸３を、回転駆動手段をもって、所定の試験片周速に応じた回転速度で回転させて、砥石周速と、試験片周速との間に、所期した通りの周速差をもたらすことによって実現することができ、実際の摩耗試験は、このような周速差で回転する砥石１と試験片４とを、可動ベース８の進出変位下にて所定の力で押圧することによって、または、それらの両者の押圧後に、砥石１および試験片４のそれぞれを所定の周速で回転させることによって開始することができる。
【００２２】
かくして、この発明によれば、弾性体試験片４の、試験条件下での周長を、高い精度をもって測定することができ、これにより、試験条件下での、所要のスリップ率に応じた周速を十分正確に求めることができるので、スリップ率の設定精度を、理論直径を用いる従来技術に比してはるかに高めることができ、この結果として、摩耗試験の試験精度を効果的に向上させることができる。
【００２３】
【発明の効果】
以上に述べたところから明らかなように、この発明の方法によれば、スリップ率の設定精度を高めて、摩耗試験精度を大きく向上させることができ、また、この発明の実施に用いることができる図示の装置によれば、弾性体試験片の周長を、簡単かつ容易に、しかも正確に測定することができる。
【図面の簡単な説明】
【図１】 この発明に係る方法の実施に用いることができ装置の要部について示す正面図および側面図である。
【図２】 図１の平面図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wear test method suitable for use in a wear test of an elastic body, for example, vulcanized rubber, and in particular, the slip ratio between a rotating grindstone and an elastic body test piece pressed against the peripheral surface thereof. The test accuracy is advantageously improved by increasing the setting accuracy.
[0002]
[Prior art]
As a test that has been widely used in the past for the abrasion test of vulcanized rubber, there is a Lambourne abrasion test, which is defined in JIS K6264.
When performing this Lambourn abrasion test using a disk-shaped vulcanized rubber as a test piece, the peripheral surface of the test piece attached to the test piece mounting part is placed on the peripheral surface of the disk-shaped polishing wheel with a predetermined pressing force. And rotating the grinding wheel and the test piece at different peripheral speeds under a predetermined slip ratio to cause wear on the peripheral surface of the test piece. The amount of wear is detected by measuring the mass of.
[0003]
[Problems to be solved by the invention]
By the way, in carrying out such a Lambourn wear test, the slip ratio represented by the following equation is used.

It is necessary to set the accuracy accurately in order to improve the test accuracy. To this end, it is essential to accurately determine the circumference of the test piece. Calculate the circumference of the specimen using the diameter, i.e., the mold dimensions if the specimen is produced by mold vulcanization, and the dimensions of the cutting blade if the specimen is produced by cutting. Since the peripheral speed of the test piece was calculated from the above, when the vulcanization return occurs in the test piece or when the cutting edge becomes worse, the theoretical diameter of the test piece and the actual There is a non-negligible variation between the static diameter and the radial direction of the test piece by holding the test piece in the thickness direction at the test piece mounting part of the wear test device in the wear test. The elastic deformation of the The elastic deformation of the test piece by pressing the one peripheral surface against the grindstone surface with a predetermined force is inevitable, and these are also the diameters between the theoretical diameter of the test piece and the actual diameter at the time of the test. Because of the variation, there is often a large gap between the specimen peripheral speed set based on the theoretical diameter and its actual peripheral speed during the test. In many cases, the desired slip ratio cannot be achieved, and this is particularly true when setting a slip ratio as small as 1 to 5% and performing a wear test. As a result, there is a problem that it greatly affects the accuracy of the wear test.
[0004]
The present invention advantageously solves such problems of the prior art, and measures the circumference of the test piece for each test piece under the condition where the actual test conditions are given, and the measurement result. By setting the slip ratio based on the above, it is possible to greatly increase the setting accuracy of the slip ratio regardless of the magnitude of the slip ratio and provide an elastic body wear test method that can effectively improve the test accuracy. is there.
[0005]
[Means for Solving the Problems]
According to the wear test method for an elastic body of the present invention, the peripheral surface of a disk-shaped elastic body test piece held by a holder is pressed against the peripheral surface of the rotating grindstone, and the rotating grindstone and the elastic body test piece are Before the start of the wear test in which the elastic test piece is worn by rotating at different peripheral speeds around the rotation axis parallel to the elastic test piece, the elastic test piece held by the holder and rotated freely is the same as during the test. The rotating grindstone is pressed at the same speed as that of the test, and the elastic test specimen is rotated at a peripheral speed equal to the grindstone peripheral speed by the frictional force against the grindstone. The number of pulses generated from the grindstone side is compared by comparing the pulse generated at least every rotation of the elastic specimen with the pulse generated at every predetermined rotation angle of the grindstone having a known circumference. Based on elastic specimen Seeking circumference during test, from the circumferential length, and calculates a peripheral speed at the time of the test of the elastic body specimens.
[0006]
In this test method, for example, one pulse is generated per revolution of an elastic specimen having an unknown circumference, and 6000 pulses are generated per revolution of an elastic specimen having a known circumference. As a thing, when the elastic body test piece held by the holder is pressed against the grindstone peripheral surface under the same conditions as the test conditions, and when the test piece is rotationally driven at a peripheral speed equal to the grindstone peripheral speed during the test, This is also the case, for example, by counting the generated pulses on the grinding wheel side per revolution of the test piece having a diameter much smaller than the grinding wheel diameter, or conversely, the generation on the specimen side per revolution of the grinding wheel. A test piece under the same conditions as in the test by counting the pulses and calculating the circumference of the test piece based on the number of pulses generated on the grinding wheel side whose circumference corresponding to the pulse interval is known in advance. The circumference of the can be easily Because it can measure with high accuracy, calculating the required test piece peripheral speed at the time of testing with this circumference can sufficiently increase the setting accuracy of the slip ratio and greatly improve the wear test accuracy. it can.
[0007]
An elastic body wear test apparatus that can be used for carrying out the method according to the present invention includes a grindstone drive shaft on which a rotating grindstone is mounted, and extends parallel to the grindstone drive shaft and faces the grindstone circumferential surface. And a test piece drive shaft having a clutch in the middle portion thereof, and at least one turn of the elastic test piece on the test piece drive shaft side. Pulse generating means for generating a pulse every time is provided, and further, other pulse generating means for generating a pulse at every predetermined rotation angle of the rotating grindstone is provided on the grindstone driving shaft side.
[0008]
In such a test apparatus, before starting the actual wear test, the elastic body test piece is held by the holder, and the test piece is allowed to freely rotate under the release of the clutch. The circumferential surface of the test piece is pressed against the grinding wheel circumferential surface with a force equivalent to the pressing force at the time of testing, and the grinding wheel is rotated at the circumferential speed at the time of testing, so that the elastic body test piece is equal to the circumferential speed of the grinding wheel. by rotation about him fast, for example, while the specimen is rotated 1 counts the number of pulses generated from the grinding wheel side, and a known circumferential length and number of pulses corresponding to the pulse interval by totalized The circumference of the test piece under the same conditions as the test conditions can be determined easily and accurately.
[0009]
In this case, the circumference measurement accuracy can be further increased by increasing the number of generated pulses per rotation of the grindstone, and the circumference measurement for the same test piece is performed, for example, 20 to 30 times. By averaging them, the influence of measurement errors and the like can be made sufficiently small.
[0010]
Therefore, at the start of the wear test thereafter, the desired slip rate is accurately obtained by rotating the test piece at the required peripheral speed calculated based on the test piece circumference obtained as described above. The wear test accuracy can be greatly improved.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below based on the drawings.
FIG. 1 is a front view and a side view showing an essential part of an apparatus that can be used for carrying out the method according to the present invention, and FIG. 2 is a plan view thereof.
In the figure, reference numeral 1 denotes a rotating grindstone having a known diameter, 2 denotes a grindstone driving shaft having the rotating grindstone 1 attached to one end thereof, and this grindstone driving shaft has the other end thereof, a servo motor (not shown), etc. Connected to the rotation drive means.
[0012]
Here, a test piece drive shaft 3 is disposed so as to extend in parallel with the grindstone drive shaft 2, and a holder for holding a disc-shaped elastic body test piece 4 at one end of the test piece drive shaft 3. 5 is provided, and the other end is connected to a rotation driving means (not shown) which is separate from the rotation driving means, and a clutch 6 is provided at an intermediate portion thereof.
[0013]
Here, the holder 5 includes a receiving pad 5a provided on the drive shaft side and a clamp pad 5b that is moved forward and backward with respect to the receiving pad 5a by, for example, a cylinder 7 disposed at a position directly below the test piece drive shaft 3. These pads 5a and 5b hold the elastic test piece 4 arranged between them with a required force from the thickness direction of the pad 5a and 5b so that the peripheral surface of the test piece faces the peripheral surface of the grindstone 1. Position. Therefore, here, based on the rotation operation of the test piece drive shaft 3, the test piece 4 rotates with the pads 5a and 5b at the same speed as the drive shaft 3.
[0014]
Here, the clutch 6 functions to control connection / disconnection of the test piece drive shaft 3, more directly the holder 5, to the rotational drive means. By releasing the clutch 6, The specimen 4 is allowed to rotate freely.
[0015]
By the way, as is apparent from FIG. 2, such a test piece drive shaft 3 is mounted on a movable base 8, and this movable base 8 is laid on a fixed base 9, for example. Under the action of 10, by making it possible to move forward and backward in a direction perpendicular to the axis of the test piece drive shaft 3, it can approach and move away from it while maintaining a parallel state with the grindstone drive shaft 2. .
[0016]
In addition, this device, the rotary shaft 11 of the clan Pupaddo 5b of the holder 5, provided it is passed through the housing 12 to the bearing support, and the end portion of the rotary shaft 11, the circumferential direction of the appropriate positions, one in FIG. A reflection disk 13 having a cutout portion only at a place is fastened and fixed, and a light sensor 14 having a light emitting part for the reflection disk 13 and a light receiving part for the reflected light from the reflection disk 13 is provided in the housing 12. And the reflection disk 13 and the optical sensor 14 constitute a pulse generating means for generating one pulse per one rotation of the test piece 4.
[0017]
The pulse generating means is configured such that the light reflected from the light emitting portion of the optical sensor 14 passes through the cutout portion 13a provided in the reflective disc 13 by rotating the reflective disc 13 and thus the test piece 4 once. Each time the reflected light is not incident on the sensor light receiving portion, it functions to generate one pulse.
[0018]
On the other hand, on the rotating grindstone side, for example, 6000 or more pulses are generated per rotation of the grindstone 1 in relation to its rotational driving means, which can be a servo motor, for example. A pulse generating means is provided.
[0019]
When a wear test of an elastic body test piece is performed using the apparatus configured as described above, the elastic test piece 4 is held in the holder 5 and the test piece drive shaft is set prior to the start of the test. 3, the test piece drive shaft 3, or directly the movable base 8, is advanced and displaced toward the grindstone drive shaft side under the action of an advancing / retreating drive means (not shown). The peripheral surface of the piece 4 is pressed against the peripheral surface of the grindstone 1 with a force equivalent to that during the wear test, and the grindstone 1 is rotated at a speed equal to the peripheral speed during the test, thereby elastic test piece 4 Is rotated at a peripheral speed equal to the peripheral speed of the grindstone by the pressing frictional force on the grindstone 1.
Then, during such rotation, the pulses generated from the grinding wheel side and the test piece side are counted together, and as described above, the circumference corresponding to the pulse interval is based on the generated pulses on the known grinding wheel side. Then, the test piece circumference under the same condition as the test condition is calculated.
[0020]
Therefore, at the start of the wear test thereafter, the slip rate is reduced to a large or small value by obtaining the test piece peripheral speed corresponding to the required slip rate based on the test piece circumference obtained as described above. Regardless, it can be set with high accuracy.
[0021]
By the way, this slip ratio is set in a wear test in which the clutch 6 of the test piece drive shaft 3 is brought into a connected state and the drive shaft 3 is rotated according to a predetermined test piece peripheral speed. It can be achieved by rotating at the rotational speed to bring the desired circumferential speed difference between the grinding wheel circumferential speed and the specimen circumferential speed. Each of the grindstone 1 and the test piece 4 is predetermined by pressing the grindstone 1 and the test piece 4 rotating by the difference with a predetermined force under the advance displacement of the movable base 8 or after pressing both of them. It can be started by rotating at a peripheral speed.
[0022]
Thus, according to the present invention, the circumferential length of the elastic specimen 4 under the test conditions can be measured with high accuracy, whereby the circumference corresponding to the required slip ratio under the test conditions can be measured. Since the speed can be obtained sufficiently accurately, the setting accuracy of the slip ratio can be greatly increased compared to the conventional technology using the theoretical diameter, and as a result, the test accuracy of the wear test is effectively improved. be able to.
[0023]
【The invention's effect】
As is apparent from the above description, according to the method of the present invention, the setting accuracy of the slip ratio can be increased, the wear test accuracy can be greatly improved, and it can be used in the practice of the present invention. According to the illustrated apparatus, the circumference of the elastic body test piece can be measured easily, easily and accurately.
[Brief description of the drawings]
1A and 1B are a front view and a side view showing a main part of an apparatus that can be used for carrying out a method according to the present invention.
FIG. 2 is a plan view of FIG.

Claims (1)

The peripheral surface of the disk-shaped elastic body test piece held by the holder is pressed against the peripheral surface of the rotating grindstone, and each of the rotating grindstone and the elastic body test piece is moved around the rotation axis parallel to each other. A wear test method in which an elastic specimen is worn by rotating at high speed,
Prior to the start of the test, the elastic test specimen held by the holder and made rotatable is pressed against the rotating grindstone with the same force as during the test, and the rotating grindstone is rotated at the same peripheral speed as during the test. Then, the elastic test piece is driven at a peripheral speed equal to the peripheral speed of the grindstone, a pulse generated at least every rotation of the elastic test piece, and a pulse generated at every predetermined rotation angle of the grindstone having a known peripheral length The circumference of the elastic specimen is tested based on the number of pulses generated from the grindstone, and the circumferential speed of the elastic specimen is calculated from this circumference. An abrasion test method for elastic bodies.

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