JP2014044068A - Biaxial tension test device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biaxial tension test device which can accurately execute a biaxial tension test by minimizing a difference in amounts of shrinkage between a link member moving to a first axis direction and a link member moving to a second axis direction so that the difference can be ignored.SOLUTION: A biaxial tension test device comprises: a rotating plate 11; a rotary drive transmission member 15 which rotates the rotating plate 11 around a central axis O; four sliders 21 to 24 which can be moved in four directions, respectively; and four link members 31 to 34 of which one ends are connected with the rotating plate 11 in a rotatable manner and other ends are connected with the respective sliders. When the rotating plate 11 rotates around the central axis O, the respective sliders 21 to 24 are configured to move in the four directions in a retractable manner by the link members 31 to 34. Test specimens holding means 41 to 44 which hold a test specimen 1 are directly or indirectly attached to the sliders 21 to 24, respectively.

Description

  The present invention relates to a tensile test apparatus used for, for example, a biaxial tensile test of a thin plate material, and performs a biaxial tensile test by simple means using a general-purpose facility such as a uniaxial tensile tester or a rotary drive device. The present invention relates to a biaxial tensile test apparatus that can

  Conventionally, as a biaxial tensile test apparatus, for example, techniques shown in Patent Document 1 and Non-Patent Document 1 are known. In the biaxial tensile testing apparatus shown in this document, a hydraulic jig in which gripping jigs that are movable in biaxial directions perpendicular to each other for gripping a cross-shaped thin plate test piece are arranged along four directions of two axes. Each is fixed to the tensile test shaft of the cylinder. And according to this biaxial tensile test apparatus, the thin plate test piece held by the gripping jig is pulled in four directions by driving these four hydraulic cylinders, thereby performing the biaxial tensile test on the test piece. This is possible.

By the way, in the biaxial tensile testing apparatus as described above, it is necessary to use four hydraulic cylinders for pulling the test pieces in four directions along two orthogonal axes. There is a problem that it is difficult to drive in synchronization with the direction and to align the axes of the hydraulic cylinders.
Further, in the technique described in Non-Patent Document 1, among hydraulic cylinders arranged on mutually orthogonal axes, two hydraulic cylinders arranged on the same axis are supplied with pressure oil from the same hydraulic source. In addition, the displacement of two hydraulic cylinders arranged on the same axis is forcibly made equal by an equal displacement mechanism such as a pantograph. However, even in this case, it is necessary to adjust to synchronize the displacement of the hydraulic cylinders arranged on the axes orthogonal to each other.

  Therefore, as means for solving the above-mentioned problem, for example, Patent Document 2 discloses a set of rotating plates that are arranged parallel to each other and are relatively rotatable, and a rotation axis of the rotating plate. It has four link sets provided at 90 ° intervals in the circumferential direction, and can perform tensile tests in four directions along a first axis and a second axis that are orthogonal to each other with a drive means such as one hydraulic cylinder. A biaxial tensile testing device is disclosed.

  According to the biaxial tensile test apparatus described in Patent Document 2, the pulling operations can be performed in synchronism with each other in four directions, and axes orthogonal to each other like a conventional mechanism using four hydraulic cylinders. Axis alignment (adjustment to synchronize displacement between hydraulic cylinders) between them becomes unnecessary.

Japanese Patent Laid-Open No. 06-109609 JP 2010-210442 A

Plasticity and processing (Journal of Japan Society for Technology of Plasticity) Vol. 40, No. 457 (1999-2), pages 145-149 “Measurement of iso-plastic work surface of cold rolled steel sheet by biaxial tensile test using cross-shaped specimens Formula "

  By the way, in the biaxial tensile testing apparatus disclosed in Patent Document 2, the second shaft is formed by pulling the link sets moving in the first axial direction so as to be separated from each other by driving means such as one hydraulic cylinder. The link sets moving in the direction move so as to be separated from each other, and the biaxial tensile test is performed.

Here, a tensile stress acts on the link set pulled in the first axial direction by a hydraulic cylinder or the like. On the other hand, in the link set that moves in the second axial direction, the link set is pressed and moved in a direction away from each other by the rotating plate, and therefore compressive stress acts.
Therefore, the link group moving in the first axial direction is deformed in the extending direction, and the link group moving in the second axial direction is deformed in the contracting direction. For this reason, the length of the link group moving in the first axis direction is different from the length of the link group moving in the second axis direction, and the link member during the tensile test is different in the first axis direction and the second axis direction. There was a possibility that the biaxial tensile test could not be carried out with high accuracy because of a difference in strain.

  The present invention has been made in consideration of such circumstances, and its purpose is to use a general-purpose facility such as a uniaxial tensile tester or a rotary drive device along the first axis and the second axis that are orthogonal to each other. It is possible to perform a tensile test in four directions and perform the pulling operations in synchronization with each other in the four directions, and the amount of contraction of the link member during the tensile test in the first axial direction and the second axial direction. The difference is so small that it can be ignored, and it is an object of the present invention to provide a biaxial tensile test apparatus capable of accurately performing a biaxial tensile test.

  In order to achieve the above object, the present invention employs the following means. That is, the biaxial tensile test apparatus of the present invention is a biaxial tensile test apparatus that performs a tensile test of the test piece by pulling the test piece along four directions of two axes orthogonal to each other. A rotary drive transmission member that rotates the rotary plate around a central axis, four sliders that can move in each of the four directions, one end rotatably connected to the rotary plate, and the other end of each slider Four link members connected to each other, and when the rotating plate rotates around a central axis, the slider is configured to move forward and backward in the four directions by the link members. Each of the sliders is directly or indirectly attached with a test piece holding means for holding the test piece, and the test piece holding means is connected to the slider. It is characterized in that the displacement distance equal.

  In the biaxial tensile test apparatus of the present invention configured as described above, a rotation drive transmission member that rotates the rotation plate around the central axis is provided, and by rotating the rotation plate by this rotation drive transmission member, Since the four sliders to which the test piece holding means for holding the test pieces are directly or indirectly attached move along the four directions of two axes perpendicular to each other, the rotational drive transmission member The biaxial tensile test can be carried out using only the driving means for rotating the rotating plate via the.

  Further, since the four link members press and move the corresponding four sliders by rotating the rotating plate, compressive stress acts on all the four link members. . Therefore, when the displacement amount in the first axial direction and the second axial direction is the same, the length of the link member does not differ between the first axial direction and the second axial direction, and the first axial direction and the second axial direction Thus, there is no difference in the shrinkage amount of the link member during the tensile test, and the biaxial tensile test can be performed with high accuracy. Further, even when the displacement amount between the first axial direction and the second axial direction is different, for example, when the displacement ratio between the first axial direction and the second axial direction is 2 to 1, the amount of contraction of the link member in each direction due to the compressive stress is Since the difference is so small that it can be ignored, the ratio of the link lengths during the test maintains the above ratio, and even in this case, the biaxial tensile test can be performed with high accuracy.

Here, the rotation drive transmission member may be a drive link member having one end connected to the rotating plate and the other end connected to a linear drive means.
In this case, by using linear drive means such as a uniaxial tensile tester or a hydraulic cylinder, the rotating plate can be rotated around the central axis, and a biaxial tensile test can be easily performed.

Further, the test piece holding means has a grip portion for gripping an end portion of the test piece and a support portion connected to the slider, and an urging means is provided between the grip portion and the support portion. It may be.
In this case, by appropriately setting the elastic coefficient (for example, spring constant) of the urging means provided between the gripping part and the support part, the displacement is converted into a load, and the four directions along the two axes by the load control are converted. A tensile test of the test piece becomes possible.

  According to the present invention, it becomes possible to perform a tensile test in four directions along the first axis and the second axis orthogonal to each other by using general-purpose equipment such as a uniaxial tensile tester and a rotary drive device, and the pulling operation thereof. Can be performed synchronously with each other in the four directions, and the difference in the amount of shrinkage of the link member during the tensile test between the first and second axial directions is so small that it can be ignored, and the biaxial tensile test is performed with high accuracy. It is possible to provide a biaxial tensile testing apparatus capable of performing the above.

It is front explanatory drawing which shows the biaxial tension test apparatus which is the 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows the whole biaxial tension test apparatus which is the 1st Embodiment of this invention, Comprising: (a) is a front view of the part comprised by a rotating plate and a 1st-4th slider, (b). FIG. 3 is a front view of a test piece holding means portion. BRIEF DESCRIPTION OF THE DRAWINGS It is a front view which shows the detail of the part comprised by the rotating plate of the biaxial tension test apparatus which is the 1st Embodiment of this invention, and the 1st-4th slider, Comprising: (a) is the 1st and 3rd slider. FIG. 5B is a front view showing a state in which the second and fourth sliders are located in directions close to each other, and FIG. 6B is a front view showing a state in which the first and third sliders and the second and fourth sliders are moved away from each other. FIG. It is a figure which shows operation | movement of the biaxial tension test apparatus which is the 1st Embodiment of this invention. It is front explanatory drawing which shows the front view of the part comprised with the rotating plate of the biaxial tension test apparatus which is the 2nd Embodiment of this invention, and a 1st-4th slider. It is a figure which shows operation | movement of the biaxial tension test apparatus which is the 2nd Embodiment of this invention. It is a front view of the test piece holding | maintenance means part of the biaxial tension test apparatus which is the 3rd Embodiment of this invention.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 illustrates a tensile test by pulling a cross-shaped test piece 1 along four directions (directions indicated by arrows A, B, C, and D) of a first axis S1 and a second axis S2 orthogonal to each other. 1 is a diagram showing an axial tension test apparatus 10. FIG. It should be noted that slits are formed in the four directions of the cross-shaped test piece 1 so that, when pulled, the test piece 1 is not subject to deformation resistance except for the central portion of the test piece 1 with respect to loads in directions orthogonal to each other. ing.

  Here, as shown in FIG. 2A, the biaxial tensile test apparatus 10 according to the present embodiment includes a rotating plate 11 and a drive link member 15 for rotating the rotating plate 11 around the central axis O. And first to fourth sliders 21, 22, 23, and 24 that move movably along the four directions of the first axis S1 and the second axis S2, respectively, and one end thereof is rotatably connected to the rotating plate 11. In addition, the first to fourth link members 31, 32, 33, and 34 are connected to the first to fourth sliders 21, 22, 23, and 24, respectively. In the present embodiment, the first to fourth sliders 21, 22, 23, 24 are support pins that pivotally support the other ends of the first to fourth link members 31, 32, 33, 34. The support pin is configured to move along the four directions of the first axis S1 and the second axis S2.

Here, as shown in FIG. 1, the first to fourth sliders 21, 22, 23, 24 have first to fourth test strip holders 41, 42, 42 for holding the test strip 1, respectively. 43 and 44 are attached.
As shown in FIG. 2B, the first to fourth test piece holding means 41, 42, 43, 44 for holding the test piece 1 described above are gripping portions 41 </ b> A for holding the end of the cross-shaped test piece 1. , 42A, 43A, 44A and support portions 41B, 42B, 43B, 44B connected to the first to fourth sliders 21, 22, 23, 24.
Moreover, it arrange | positions so that either one or both between the holding part 41A and the support part 41B arrange | positioned along 1st axis | shaft S1 and between the holding part 43A and support part 43B may follow 2nd axis | shaft S2. Load cells for load measurement are provided between the gripping portion 42A and the support portion 42B, and between or both of the gripping portion 44A and the support portion 44B, but are not shown in the figure.

  Here, as shown in FIGS. 3A and 3B, in the present embodiment, the first to fourth sliders 21, 22, 23, and 24 are arranged on the first axis S1 and the second axis S2. It is configured to be guided by an extending guide member (not shown). The first slider 21 is in the direction of arrow A, the second slider 22 is in the direction of arrow C, and the third slider 23 is in the direction of arrow B. The fourth sliders 24 are arranged so as to move in the direction of arrow D, respectively.

As shown in FIG. 2A, the rotating plate 11 is pivotally supported by the shaft portion 12 and is configured to be rotatable around the central axis O. In the present embodiment, the rotating plate 11 has a substantially cross shape, and the four directions of the first axis S1 and the second axis S2 on which the first to fourth sliders 21, 22, 23, 24 are disposed. The region is cut out so as to be recessed radially inward.
One end of each of the first to fourth link members 31, 32, 33, 34 is connected to a radially inner side portion of the rotating plate 11, and the other is connected to the first to fourth sliders 21, 22, 23, 24, respectively. It is connected. As shown in FIG. 2 (a), in the present embodiment, one end of each of the first to fourth link members 31, 32, 33, 34 corresponds to the corresponding first to fourth sliders 21, 22, 23, 24 is connected to the region located in the rear side portion in the rotational direction R with respect to the first axis S1 or the second axis S2 that moves.

One end of the drive link member 15 is connected to a radially outer side portion of the rotating plate 11, that is, a portion other than the notched region. In this embodiment, as shown to Fig.2 (a), the end of the drive link member 15 is connected with the area | region located in the rotation direction R direction back side part with respect to 1st axis | shaft S1.
As shown in FIG. 1, the rotary plate 11 is configured such that the other end of the drive link member 15 is connected to the tip of the rod 6 of the hydraulic cylinder 5. It is configured to rotate around.

Next, the operation of the biaxial tensile test apparatus 10 having the above configuration will be described.
This biaxial tensile testing apparatus 10 is used by being connected to the hydraulic cylinder 5 as described above. Specifically, as shown in FIG. 1, the shaft portion 12 of the rotating plate 11 is fixed, and the other end of the drive link member 15 is connected to the tip of the rod 6 of the hydraulic cylinder 5. In the present embodiment, the rod 6 of the hydraulic cylinder 5 is arranged so that the protruding direction of the rod 6 coincides with the first axis S1.

  1 and 2B, one end on the first axis S1 of the cross-shaped test piece 1 is held by the first test piece holding means 41, and the first axis of the test piece 1 is held. The other end on S1 is held by the third test piece holding means 43, one end on the second axis S2 of the test piece 1 is held by the second test piece holding means 42, and the other on the second axis S2 of the test piece. The end is held by the fourth test piece holding means 44. At this time, the central portion of the test piece 1 is located at the intersection of the first axis S1 and the second axis S2.

In this state, as shown in FIG. 1, the drive link member 15 is pulled toward the direction A along the first axis S1 by the hydraulic cylinder 5. Then, as illustrated in FIGS. 3A and 3B, the rotating plate 11 is rotated in the rotation direction R by the drive link member 15.
As the rotary plate 11 rotates, the first link member 31 presses the first slider 21 in a direction away from the central axis O of the rotary plate 11, and the second link member 32 presses the second slider 22. The third link member 33 presses the third slider 23 in the direction away from the central axis O of the rotary plate 11, and the fourth link member 34 presses in the direction away from the central axis O of the rotary plate 11. The four sliders 24 are pressed in a direction away from the central axis O of the rotating plate 11.
Here, as shown in FIG. 3B, the first slider 21 and the third slider 23 are guided so as to move on the first axis S1, so that they move in the directions of the arrow A and the arrow B, respectively. Moving. Further, since the second slider 22 and the fourth slider 24 are guided so as to move on the second axis S2, they move in the direction of the arrow C and the direction of the arrow D, respectively. As a guide method, there is a method of providing a plate in which a guide member such as a rail is disposed between a support pin and a slider.

Accordingly, as shown in FIGS. 1 and 4, the test piece 1 is formed by the first test piece holding means 41 attached to the first slider 21 and the third test piece holding means 43 attached to the third slider 23. It will be pulled along the first axis S1.
Further, as shown in FIGS. 1 and 4, the second test piece holding means 42 attached to the second slider 22 and the fourth test piece holding means 44 attached to the fourth slider 24 make the test piece 1 the first. It will be pulled along the biaxial S2.
In this way, the biaxial tensile test in the four directions of the first axis S1 and the second axis S2 orthogonal to each other is performed.

  According to the biaxial tensile test apparatus 10 of the present embodiment configured as described above, the drive link member 15 is moved by the hydraulic cylinder 5 and the rotating plate 11 is rotated in the rotation direction R. The first to fourth link members 31, 32, 33, 34 are configured to move the first to fourth sliders 21, 22, 23, 24 along four directions of two axes orthogonal to each other. Since the first to fourth test piece holding means 41, 42, 43, 44 for holding the test piece 1 are attached to the first to fourth sliders 21, 22, 23, 24, one hydraulic cylinder 5 makes it possible to carry out a biaxial tensile test.

  Further, as the rotary plate 11 rotates, the first link member 31 presses the first slider 21 in a direction away from the central axis O of the rotary plate 11, and the second link member 32 presses the second slider 22. Is pressed in a direction away from the central axis O of the rotating plate 11, the third link member 33 presses the third slider 23 in a direction away from the central axis O of the rotating plate 11, and the fourth link member 34 is Since the fourth slider 24 is configured to be pressed in a direction away from the central axis O of the rotating plate 11, a compressive stress acts on all of the first to fourth link members 31, 32, 33, and 34. It will be. Therefore, the first to fourth link members 31, 32, 33, and 34 are not deformed to have different lengths, and the first shaft S1 and the second shaft S2 have no difference in displacement during the tensile test. The biaxial tensile test can be performed with high accuracy.

In the present embodiment, the rotating plate 11, the first to fourth link members 31, 32, 33, and 34 and the drive link member 15 are connected at different positions, so that the rotating plate 11 and the first to first link members are connected. The out-of-plane deformation of the four link members 31, 32, 33, and 34 is suppressed, and the biaxial tensile test can be performed with higher accuracy.
Furthermore, in this embodiment, since the area | region notched radially inward was formed in the rotating plate 11, the weight reduction of the rotating plate 11 can be achieved.

<Second Embodiment>
A biaxial tensile test apparatus according to a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

As shown in FIG. 5, in the biaxial tensile test apparatus 110 according to the second embodiment, the second link member 132 coupled to the second slider 122 and the fourth slider 124 that move along the second axis S2. And the length of the 4th link member 134 is longer than the length of the 1st link member 131 and the 3rd link member 133 which are connected with the 1st slider 121 and the 3rd slider 123 which move along the 1st axis S1. In this embodiment, the length is doubled.
In the rotating plate 11, the lengths r2 and r4 in the radial direction from the central axis O at the position where one ends of the second link member 132 and the fourth link member 134 are connected are the first link member 131 and the third link member. The radial lengths r1 and r3 from the central axis O at the position where one end of 133 is connected are doubled.

  With such a configuration, in the biaxial tensile testing apparatus 110 according to the second embodiment of the present invention, as shown in FIG. 6, the displacement amount in the second axis S2 direction is set in the first axis S1 direction. It is possible to perform a biaxial tensile test that is larger than the displacement. Specifically, the amount of displacement in the second axis S2 direction is twice the amount of displacement in the first axis S1 direction. In this way, by adjusting the lengths and connecting positions of the first to fourth link members 131, 132, 133, 134, the displacement amount in the first axis S1 direction and the displacement amount in the second axis S2 direction can be easily achieved. A biaxial tensile test with different values can be performed.

<Third Embodiment>
A biaxial tensile test apparatus according to a third embodiment of the present invention will be described with reference to FIG. In the third embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 7, in the biaxial tensile test apparatus 210 according to the third embodiment, the first to fourth test piece holding means 241, 242, 243, and 244 are gripping portions 241A, 242A, 243A, and 244A. , And support portions 241B, 242B, 243B, 244B, and between the grip portions 241A, 242A, 243A, 244A and the support portions 241B, 242B, 243B, 244B, the grip portions 241A, Tension springs 241C, 242C, 243C, and 244C that urge 242A, 243A, and 244A outward along the first axis S1 or the second axis S2 are provided.

  By adopting such a configuration, in the biaxial tensile test apparatus 210 according to the third embodiment of the present invention, the gap between the grip portions 241A, 242A, 243A, 244A and the support portions 241B, 242B, 243B, 244B. By appropriately changing the spring constants of the tension springs 241C, 242C, 243C, and 244C provided in the test, it is possible to perform a test in which the stress ratio to the first axis S1 or the second axis S2 is changed.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.
For example, although the present embodiment has been described as a configuration in which the rotating plate is rotated by the hydraulic cylinder, the present invention is not limited to this, and the drive link member may be linearly moved by a single-axis tensile tester. .
Alternatively, a rotation drive transmission member that transmits a driving force from the rotation drive device may be provided on the rotation plate, and the rotation plate may be rotated by a rotation drive device such as a servo motor.

Moreover, although this embodiment demonstrated the support pin which pivotally supports the other end of a 1st-4th link member as what was comprised as a 1st-4th slider, it is not limited to this, others A slider having the following structure may be used.
Furthermore, the shape of the rotating plate and the link member is not limited to the present embodiment, and the design may be changed as appropriate.

DESCRIPTION OF SYMBOLS 1 Test piece 10,110,210 Biaxial tension test apparatus 11 Rotating plate 15 Drive link member (rotation drive transmission member)
21, 121 First slider 22, 122 Second slider 23, 123 Third slider 24, 124 Fourth slider 31, 131 First link member 32, 132 Second link member 33, 133 Third link member 34, 134 Fourth Link members 41, 241 First test piece holding means 42, 242 Second test piece holding means 43, 243 Third test piece holding means 44, 244 Fourth test piece holding means 41A, 42A, 43A, 44A, 241A, 242A, 243A, 244A Grip part 41B, 42B, 43B, 44B, 241B, 242B, 243B, 244B Support part 241C, 242C, 243C, 244C Tension spring (biasing means)

Claims (3)

A biaxial tensile testing device for performing a tensile test of a test piece by pulling the test piece along four directions of two axes perpendicular to each other,
A rotary plate, a rotary drive transmission member that rotates the rotary plate about a central axis, four sliders that can move in each of the four directions, one end rotatably connected to the rotary plate, and the other Four link members having ends connected to the sliders,
The slider is configured to move forward and backward in each of the four directions by the link member by rotating the rotating plate around a central axis.
A test piece holding means for holding the test piece is attached to the slider directly or indirectly, and the test piece holding means is displaced by the same distance as the slider. Tensile test device.   2. The biaxial tensile testing apparatus according to claim 1, wherein the rotation drive transmission member is a drive link member having one end connected to the rotating plate and the other end connected to a linear drive unit.   The test piece holding means has a grip portion for gripping an end portion of the test piece and a support portion connected to the slider, and an urging means is provided between the grip portion and the support portion. The biaxial tensile testing apparatus according to claim 1 or 2, wherein

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