JP2000046726A - Exfoliation testing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an exfoliation testing apparatus which prevents a drop in the testing accuracy due to the twist deformation or the like of a test piece and in which the action direction of an exfoliation external force onto the test piece is made more approximate to an actual tire. SOLUTION: In an exfoliation testing apparatus, a chuck 1, on one side, which is displaced relatively in a direction brought close and separated mutually and which sandwiches the exfoliation starting end 4 of a test piece 3 is provided, and a chuck 2, on the other side, which sandwiches the remaining part 8 of the test piece 3 nearly wholly is provided. In the exfoliation testing apparatus, the action direction of an exfoliation external force onto the test piece 3 is set in a direction which is nearly at right angles to the remaining part 8 of the test piece 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a peeling test apparatus suitable for measuring, for example, the adhesive strength of various tires between laminated rubber layers and between a reinforcing layer and a rubber layer. It is.

[0002]

2. Description of the Related Art For example, when a test piece cut from a tire is used to measure the adhesive strength between the laminated rubber layers, one peeling start end of the test piece is measured by an upper chuck, and the other peeling test is performed. With the start ends clamped by the lower chuck, each peeling start end is moved vertically.
In other words, it is general that both of them are pulled in a direction forming approximately 180 ° to obtain a tensile load at which both rubber layers are separated.

[0003]

However, in the prior art described above, each of the peeling start ends of the test pieces is pulled by a pair of upper and lower chucks in an almost 180 ° widening posture, so that the peeling still occurs. Is not progressing,
The portion to be tested will be substantially free from this, and therefore, if the laminated rubber layer has a reinforcing cord or the like embedded in the layer, the cord or the like will proceed as the test proceeds. When a tensile force acts on the free portion, the free portion is twisted in relation to the direction in which the cord or the like extends, and this twisting deformation causes a reduction in test accuracy. Since the mode of delamination under a spreading position of about 180 ° is significantly different from the delamination that may occur in an actual tire in terms of the direction of force application, the test results according to the prior art are: There is also a problem that the tire cannot be used immediately for evaluation of the adhesive strength.

An object of the present invention is to solve such a problem in the prior art. In particular, a test piece held by a pair of chucks can be freely deformed or the like. By completely removing the peeled part,
Effectively removes the possibility of deterioration in test accuracy due to the occurrence of torsional deformation, etc., in the unpeeled part, and at the same time, changes the action direction of the peel force on the test piece to the actual direction of the peel force on the tire. It is an object of the present invention to provide a peeling test apparatus that enables near-direct use of test results by bringing them sufficiently close to each other.

[0005]

The peel test apparatus of the present invention is relatively displaced in directions approaching and moving away from each other.
One chuck that clamps the peeling start end of the test piece, and the other chuck that grips the rest of the test piece almost entirely, and the direction of action of the peeling external force on the test piece,
The direction was substantially perpendicular to the rest of the test piece.

In this apparatus, while the peeling start end of the test piece is held by one chuck, for example, an upper chuck, as in the prior art, the rest of the test piece is almost entirely held by the other chuck, for example, a lower chuck. By doing so, it is possible to completely remove a free portion such as deformation from the test piece while being sandwiched by the pair of chucks, which is a case where one or both of the laminated rubber layers has a reinforcing cord or the like. Even so, it is possible to prevent occurrence of torsional deformation of the test piece, and to always provide excellent test results.

Here, the direction in which the external force of peeling is applied to the test piece, for example, the starting end of the peeling, is substantially perpendicular to the rest of the test piece. Is much closer to the direction of action of the delamination external force on the tire, and the test results obtained thereby can be directly used for evaluation of the adhesive strength of the tire.

Here, the remaining chuck of the test piece can be almost entirely held by the other chuck, for example, by holding at least both ends of the remaining test piece with the other chuck. In addition, in addition to the above, the bending deformation of the remaining test piece is more effectively prevented by sandwiching both sides of the remaining test piece.

[0009] Preferably, at least one of the pair of chucks of the apparatus is made displaceable in a direction orthogonal to the relative displacement direction, so that the peeling of the test piece proceeds while the peeling of the test piece proceeds. It can be continued at a fixed position relative to the center axis of the chuck and always at a fixed posture. Therefore, according to this, it is possible to sufficiently prevent the occurrence of a measurement error caused by a change in the peeling position and the peeling posture.

[0010] For such an operation, the other chuck is provided with clamping means at least at both ends of the remaining test piece on a slide member which slides and displaces in a direction perpendicular to the relative displacement direction with respect to the chuck base. It can be configured by providing. Note that instead of this,
Alternatively or additionally, one of the chucks can be displaceable in the direction in which it extends in a plane substantially parallel to the holding surface of the remaining test piece.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing an embodiment of the present invention in a state where a test piece is sandwiched. Here, the main body of the test apparatus can be an Amsler-type or any other known tensile tester, and thus is not shown.

In the drawings, reference numerals 1 and 2 respectively denote a pair of chucks which are disposed in a vertical positional relationship in the figure and are relatively displaced in directions approaching and separating from each other, for example, located on a common vertical axis. The upper chuck 1 includes a pair of clamp claws that hold the peeling start end 4 intentionally peeled from the test piece 3 in the thickness direction thereof.

The lower chuck 2 has a T-groove 5 extending in the horizontal direction. The chuck 2 is attached to a chuck base 6 attached to the tester main body in a direction in which the T-groove 5 extends under a small frictional force. A slide member 7 is fitted so as to be slidably displaceable, and at least at both end portions of the slide member 7 corresponding to the extending direction of the T groove 5, the peeling start end 4 of the test piece 3 is formed.
And a clamp means 9 for clamping each end of the remaining portion 8 except for the above.

Here, it is needless to say that each of the clamping means 9 can be constituted by a cylinder or the like, but here, in relation to the thickness of the remaining test piece 8 and the like, the clamping force is appropriately adjusted as required. To enable fine adjustment, the clamping means 9 is screwed with a male screw 9b at the top of a gate-shaped frame 9a provided so as to protrude upward from a flat test piece mounting surface of the slide member 7, and Preferably, a clamping plate 9c is provided at the tip of the male screw 9b, and is preferably guided to a columnar portion of the gate-shaped frame 9a to guide the vertical displacement.

More preferably, there is also provided a clamping means 10 for holding each side of the remaining test piece 8 without hindering the peeling test. These clamping means 10
At least one male screw 10b is screwed onto the flange of an angle plate 10a having a flange projecting upward on each side of the test piece mounting surface and projecting in opposite directions at the upper end. Rather than letting
It is constituted by attaching a holding plate to the tip of the male screw 10b.

When a peeling test is performed by using the apparatus having the above-described structure, for example, the length is 20 to 30.
cm, a width of 5 to 10 cm, and a thickness of about 5 to 20 mm are prepared by cutting or vulcanizing a test piece 3 from a tire, and the cross section of the test piece 3 is formed into a convex shape as shown in FIG. The test piece 3 is cut, and the laterally protruding portion 3b of the lower rubber layer 3a is used as a portion to be clamped by the clamp means 10, and a part of the upper rubber layer 3c of the test piece 3 is used as the test piece 3, and thus the lower rubber layer. 3a is peeled in advance from one end side to form a peeling start end 4 for holding the test piece 3 by the upper chuck 1.

The test piece 3 thus prepared is clamped between the upper and lower chucks 1 and 2 by, for example, attaching both ends of the test piece remaining portion 8 and both widened side portions to the test piece remaining portion 8.
Under the horizontal posture, the respective clamping means 9 and 10 are clamped by a required force, and the peeling start end 4 is held between the clamp claws of the upper chuck 1 in a vertical rising posture.
This can be done by clamping with the required force,
In the peel test, at least one of the upward displacement of the upper chuck 1 and the downward displacement of the lower chuck 2 is performed while the test piece 3 is held in such a manner.
a and the upper rubber layer 3c are delaminated, and the load at that time can be measured by a load cell or other load meter.

By the way, in this apparatus, as the delamination of the upper and lower rubber layers progresses, the peeling position of the remaining test piece 8, that is, the corresponding portion of the slide member 7 to which it is directly attached, and the test piece 3 Based on the applied horizontal component force, the chuck base 6 is freely horizontally displaced in the direction approaching the common axis of the upper and lower chucks 1 and 2, so that the delamination is always at a constant position in the horizontal direction, and The peeled portion will be performed while keeping the attitude of the remaining test piece constant at all times, and the peeling condition does not substantially change as the peeling progresses, so that high measurement accuracy can be obtained. .

The improvement of the measurement accuracy is achieved by holding the test piece remaining portion 8 at both ends and also on both sides as shown in FIG. This is particularly noticeable when the deformation is more effectively constrained.

Thus, according to this apparatus, by holding the test piece remaining portion 8 over substantially the entirety thereof, particularly with the lower chuck 2, even if the rubber layers 3a and 3c have reinforcing cords or the like, In the peeling test, no distortion or the like is generated in the remaining portion 8 of the test piece, and therefore, there is no decrease in accuracy due to the deformation or the like.

Further, in this apparatus, delamination is performed in a posture in which the peeling start end 4 is substantially perpendicular to the remaining test piece 8, and the mode of action of the peeling external force is different from that of the actual tire. Since it is an approximation, the test result by this device can be used as it is for evaluating the adhesive strength of the tire rubber layer and the like.

Although the present invention has been described with reference to the drawings, the two chucks 1 and 2 may be configured to approach and separate from each other in a horizontal direction, for example.
Instead of or in addition to providing the chuck 2 with the free displacement mechanism, the chuck 1 may be provided with a free displacement mechanism.

[0023]

Therefore, according to the present invention, it is possible to prevent the occurrence of torsional deformation and the like in the unpeeled portion of the test piece, to provide high measurement accuracy, and to set the direction of action of the peeling external force to A close approximation to that of an actual tire allows direct use of the measurement results.

Further, here, regardless of the degree of progress of delamination, the delamination conditions are always kept constant,
Together with clamping at least both ends of the remaining test piece, it is possible to further improve the measurement accuracy,
This is particularly remarkable when not only the both ends but also both sides of the remaining test piece are sandwiched, and the bending deformation or the like of the remaining test piece is more sufficiently restrained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a test piece.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Upper chuck 2 Lower chuck 3 Test piece 3a Lower surface side rubber layer 3b Side protruding part 3c Upper side rubber layer 4 Peeling start end 5 T groove 6 Chuck base 7 Slide member 8 Test piece remaining part 9,10 Clamping means

Claims (5)

[Claims] 1. A chuck for holding a peeling start end of a test piece, which is relatively displaced toward and away from each other, and another chuck for holding the rest of the test piece almost entirely. A peeling test apparatus in which the direction in which the external peel force acts on the test piece is substantially perpendicular to the rest of the test piece. 2. The peeling test apparatus according to claim 1, wherein at least both ends of the remaining test piece are held by the other chuck. 3. The peel test apparatus according to claim 2, wherein the other chuck holds both sides of the remaining test piece. 4. The peeling test apparatus according to claim 1, wherein at least one of the pair of chucks can be displaced in a direction orthogonal to the relative displacement direction. 5. The apparatus according to claim 5, wherein the other chuck is provided with a clamp member at least at both ends of the remaining test piece on a slide member slidably displaced in a direction perpendicular to the relative displacement direction with respect to the chuck base. The peel test apparatus according to claim 4.