Biaxial tension test machine

Abstract

To provide a biaxial tension test machine which can realize a test with a constant load ratio, and which is inexpensive and simple.SOLUTION: A biaxial tension test machine pulls a test piece in four directions along two mutually orthogonal axes, and comprises: a plurality of holding parts for separately holding the test piece at portions in the four directions; a plurality of connection parts that are connected separately to the plurality of holding parts; and an installation part bridging between the plurality of connection parts like a loop.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a biaxial tensile testing machine. [Background technology]

[0002] Biaxial tensile testing machines that perform tensile tests by pulling a cross-shaped test piece are known. For example, biaxial tensile testing machines include a stress ratio control type biaxial tensile testing machine and a displacement ratio fixed type biaxial tensile testing jig. A stress ratio control type biaxial tensile testing machine maintains a constant stress ratio by feedback controlling the hydraulic cylinder of the driving source (for example, see Non-Patent Document 1). This stress ratio control type biaxial tensile testing machine can measure at a constant stress ratio until the end of the test and can provide a linear stress history, so it can be used to appropriately mathematically express the plastic properties of materials. However, since it is a highly accurate dedicated testing machine, it is expensive. A fixed-displacement-ratio biaxial tensile test jig is attached to a uniaxial tensile testing machine and the arms slide in four directions when a load is applied. This fixed-displacement-ratio biaxial tensile test jig is inexpensive because it does not have a driving source. However, because the arms of the test piece undergo elongation deformation, even the strain ratio is not constant, and as a result, tests with a constant stress ratio cannot be performed. For this reason, it is difficult to use the experimental data directly as a model of plastic properties. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Republished WO2015 / 173915 [Non-patent literature]

[0004] [Non-Patent Document 1] Development of a biaxial tensile testing machine using a servomotor hydrotech system, S.MATSUMOTO, K.TASHIRO, A.MAZAKI, S.IKEDA, K.YOSHIDA, S.TAKAHASHI, T.KUWABARA, Journal of the JSTP vol.53 no.623 (2012-12) 1065 Summary of the Invention [Problem to be solved by the invention]

[0005] The above-mentioned stress ratio control type biaxial tensile testing machine can perform measurements at a constant stress ratio (constant load ratio), but it is a dedicated testing machine and is expensive. On the other hand, the displacement ratio fixed type biaxial tensile testing jig is a test jig and is inexpensive, but it cannot control the stress ratio or strain ratio. Therefore, there is a demand for an inexpensive and easy-to-use biaxial tensile testing machine that can perform tests at a constant load ratio.

[0006] Therefore, an object of the present invention is to provide an inexpensive and simple biaxial tensile testing machine that can perform testing at a constant load ratio. [Means for solving the problem]

[0007] A biaxial tensile testing machine according to one embodiment of the present invention is a biaxial tensile testing machine that pulls a test piece along four directions of two mutually perpendicular axes, and includes a plurality of holding parts that hold the four portions of the test piece separately, a plurality of connecting parts that are respectively connected to the plurality of holding parts, and a bridging part that is bridged in a loop shape across the plurality of connecting parts. Effect of the Invention

[0008] According to the above aspect, it is possible to provide a biaxial tensile tester that can perform testing at a constant load ratio and is inexpensive and simple to use. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a state in which a biaxial tensile testing machine according to a first embodiment is assembled to a uniaxial tensile testing machine. [Diagram 2] FIG. 1 is a perspective view of a biaxial tensile testing machine according to a first embodiment. [Diagram 3] FIG. 1 is a plan view of a biaxial tensile testing machine according to a first embodiment. [Figure 4] FIG. 2 is an enlarged perspective view showing a portion of the biaxial tensile testing machine according to the first embodiment. [Diagram 5] FIG. 2 is a plan view showing a first setting example of a load ratio of the biaxial tensile testing machine according to the first embodiment. [Figure 6] FIG. 4 is a plan view showing a second setting example of the load ratio of the biaxial tensile testing machine according to the first embodiment. [Figure 7] FIG. 4 is a plan view showing a third setting example of the load ratio of the biaxial tensile testing machine according to the first embodiment. [Figure 8] FIG. 4 is a plan view showing a fourth setting example of the load ratio of the biaxial tensile testing machine according to the first embodiment. [Figure 9] FIG. 11 is a side view of a biaxial tensile testing machine according to a second embodiment. [Figure 10] FIG. 11 is a plan view of a biaxial tensile testing machine according to a second embodiment. [Figure 11] FIG. 13 is an explanatory diagram of the results of a constant load ratio preliminary test of Examples 1-4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the embodiment, as an example of a biaxial tensile tester, a uniaxial drive type biaxial tensile tester configured to be able to tensile a cross-shaped test piece by being assembled to the uniaxial tensile tester will be described.

[0011] In the following description, expressions indicating relative or absolute arrangements, such as "parallel," "orthogonal," "center," and "coaxial," do not only mean such arrangements or states strictly, but also include arrangements or states in which there is a relative displacement with an angle or distance to the extent that the same function can be obtained with a tolerance. In the drawings used in the following description, the scale of each component may be appropriately changed to show each component with a recognizable size.

[0012] First Embodiment <Uniaxial tensile testing machine> First, a uniaxial tensile tester 100 to which the biaxial tensile tester 1 is attached will be described. FIG. 1 is a perspective view showing a state in which a biaxial tensile tester 1 according to the first embodiment is assembled to a uniaxial tensile tester 100. As shown in FIG. As shown in Fig. 1, the uniaxial tensile tester 100 is a tester to which the biaxial tensile tester 1 is attached. The uniaxial tensile tester 100 is installed upright in the up-down direction (vertical direction). The uniaxial tensile tester 100 includes a base 101, a support 102, and a crosshead 103.

[0013] In the following explanation, an X, Y, Z Cartesian coordinate system is used as necessary. The X direction corresponds to the width direction of the testing machine. The Y direction corresponds to the depth direction of the testing machine. The Z direction corresponds to the height direction of the testing machine (direction of gravity) perpendicular to the X and Y directions. In the following explanation, the X, Y, and Z directions are explained with the arrows in the figures as the plus (+) side, and the opposite side to the arrows as the minus (-) side. The +Z side corresponds to the upper side in the direction of gravity, and the -Z side corresponds to the lower side in the direction of gravity.

[0014] The base 101 has a rectangular parallelepiped shape and has an upper surface that is aligned along a horizontal plane. The support pillars 102 are provided in pairs, with the base 101 in between. The lower portions of the pair of support pillars 102 are connected to the base 101. The crosshead 103 is disposed above the base 101. The crosshead 103 is disposed between a pair of support columns 102. The crosshead 103 is configured to be movable in the up-down direction.

[0015] For example, the crosshead 103 may be configured to be movable in the vertical direction by a driving mechanism such as a ball screw mechanism driven by a motor, or may be driven hydraulically. In Fig. 1, one of the pair of pillars 102 (the pillar 102 on the +X side) and the crosshead 103 are indicated by two-dot chain lines, and the upward movement (rising) of the crosshead 103 is indicated by an arrow.

[0016] <Biaxial tensile testing machine> Next, the biaxial tensile tester 1 that is assembled to the uniaxial tensile tester 100 will be described. Fig. 2 is a perspective view of the biaxial tensile tester 1 according to the first embodiment. Fig. 3 is a plan view of the biaxial tensile tester 1 according to the first embodiment. Fig. 4 is an enlarged perspective view of a portion of the biaxial tensile tester 1 according to the first embodiment. 2 to 4, the biaxial tensile tester 1 is a biaxial tensile tester that pulls the test piece 10 along the four directions of two mutually orthogonal axes. In this embodiment, the four directions of the two mutually orthogonal axes are mutually orthogonal directions along a horizontal plane. Hereinafter, the direction along the first axis of one of the two axes is referred to as the first axis direction (corresponding to the X direction), and the direction along the second axis of the other of the two axes is referred to as the second axis direction (corresponding to the Y direction). Hereinafter, one of the first axis directions may be referred to as the east (corresponding to the +X side), and the other as the west (corresponding to the -X side), and one of the second axis directions may be referred to as the north (corresponding to the +Y side), and the other as the south (corresponding to the -Y side).

[0017] The biaxial tensile tester 1 includes a plurality of holding parts 2 that hold the four directional parts of the test piece 10 separately, a plurality of connecting parts 3 that are respectively connected to the plurality of holding parts 2, and a bridge part 4 that is loop-shaped and bridged to the plurality of connecting parts 3. In this embodiment, the four directional parts of the test piece 10 are arms that extend in the four directions of the test piece 10. In addition, slits may be formed in the four directional arms of the test piece 10 so that the test piece 10 does not resist deformation other than the center of the test piece 10 against loads in mutually orthogonal directions when pulled. This test piece shape is standardized as "Biaxial tensile test method for metal sheet material using cruciform test piece" in JIS Z2257:2021.

[0018] The biaxial tensile tester 1 includes a table 11 on which a test piece 10 is placed. The table 11 is formed in the shape of a rectangular plate having four sides that overlap with the four sides of the test piece 10. The test piece 10 is arranged such that each arm protrudes in each of the four directions from each side of the table 11 in a plan view. The parts of the test piece 10 that protrude from the table 11 among the four sides are held by a holder 2.

[0019] <Holding part> The four holding parts 2 are provided corresponding to the four directions of the test piece 10. In this embodiment, the holding parts 2 are chuck mechanisms that hold the arms of the test piece 10. The holding parts 2 include a chuck body 20 configured to be able to hold the arms of the test piece 10, and a handle 21 disposed on an upper portion of the chuck body 20. The example in FIG. 4 shows how the north holding part 2 holds the north arm of the test piece 10.

[0020] The chuck body 20 has a U-shape with an opening to clamp the arm portion of the test piece 10. The handle 21 has a three-pronged shape that can be operated by a user. The handle 21 is configured to be rotatable around an axis along the vertical direction.

[0021] For example, by rotating the handle 21 in one direction about the axis, the opening of the chuck body 20 can be narrowed and the arms of the test piece 10 can be held. On the other hand, by rotating the handle 21 in the other direction about the axis, the opening of the chuck body 20 can be widened and the arms of the test piece 10 can be released from their hold.

[0022] In this embodiment, the multiple holding parts 2 are each configured with the same chuck mechanism. At least one of the multiple holding parts 2 may be configured with a different chuck mechanism, or may be configured with a holding mechanism different from the chuck mechanism. For example, the configuration of the multiple holding parts 2 can be changed according to design specifications.

[0023] <Load cell> The biaxial tensile tester 1 further includes a plurality of load cells 5 respectively connected to the plurality of holding parts 2. The plurality of load cells 5 are provided in four numbers corresponding to the four holding parts 2. In this embodiment, the load cells 5 are formed in a columnar shape. The load cells 5 are arranged along the extension line of the arm part of the test piece 10. The example of FIG. 4 shows the state where the north side load cell 5 is arranged on the extension line of the north side arm part of the test piece 10. In this embodiment, the holding part 2, the load cell 5, and the connection part 3 are arranged in this order from the center of the four directions of the test piece 10.

[0024] In this embodiment, the multiple load cells 5 are each configured with the same load cell. Note that at least one of the multiple load cells 5 may be configured with a different load cell. For example, the configuration of the multiple load cells 5 can be changed according to the design specifications.

[0025] <Connection> The multiple connection parts 3 are provided corresponding to the four directions of the test piece 10. The multiple connection parts 3 are provided corresponding to the four holding parts 2. Each of the multiple connection parts 3 includes multiple pulleys 30 across which the installation parts 4 are spanned at a position opposite the holding part 2 across the load cell 5. The example in FIG. 4 shows three pulleys 30 provided at a position opposite the holding part 2 across the load cell 5 (north side). The pulley included in the connection part 3 is movable on the slider and therefore functions as a "moving pulley", whereas the other pulleys are fixed to the device and therefore function as "fixed pulleys".

[0026] Each of the three pulleys 30 on the north side is configured to be rotatable around an axis along the vertical direction. Each of the three pulleys 30 on the south side is also configured to be rotatable around an axis along the vertical direction (see FIG. 3). Meanwhile, on each of the east side and west side, one pulley 30 is configured to be rotatable around an axis along the vertical direction (see FIG. 3). Note that the numbers of pulleys 30 arranged in the east, west, north and south directions are not limited to the above and can be changed according to design specifications.

[0027] <Erection section> In this embodiment, the erection section 4 is a rope. The rope is formed into a loop (in other words, a closed loop or closed circuit) by tying the ends together at a predetermined position. For example, the rope may be made of synthetic fibers or a metal wire. However, since the rope is used in a tied state, it is selected so that it has sufficient tying strength. Note that the form of the rope (material of formation, selection method, etc.) is not limited to the above and can be changed according to the design specifications.

[0028] In this embodiment, the angle at which the bridging portion 4 is bridged over the multiple connection portions 3 can be changed to any angle. This allows tests with various load ratios to be performed by arbitrarily changing the position at which the bridging portion 4 is bridged over the multiple connection portions 3.

[0029] <1st support part> The biaxial tensile tester 1 further includes a first support portion 40 that supports a first pulley 30 (pulleys 30-3, 30-9, 30-15, and 30-21 shown in FIG. 2 in this embodiment) that is located closest to the load cell 5 among the multiple pulleys 30. Four first pulleys 30 (one for each direction) are provided corresponding to the four directions of the test piece 10. Four first support portions 40 are provided corresponding to the four first pulleys 30 (one for each first pulley 30).

[0030] The first support part 40 is configured to include a plate-shaped horizontal part 41 that extends along a horizontal plane, and a plate-shaped vertical part 42 that extends along a vertical plane (see FIG. 4). The horizontal part 41 of the first support part 40 is a part that supports the first pulley 30. The vertical part 42 of the first support part 40 is a part to which the end of the load cell 5 opposite the holding part 2 is attached. Note that the configuration of the first support part 40 is not limited to the above, and can be changed according to design specifications.

[0031] <Guide section> The biaxial tensile tester 1 further includes a guide section 50 that guides the holding section 2 and the first support section 40 linearly in four directions. Four guide sections 50 (one in each direction) are provided corresponding to the four directions of the test piece 10. In this embodiment, the guide section 50 is a linear guide that extends linearly and parallel to the four directions of the test piece 10. The total length of the guide section 50 in the extending direction is longer than the combined length of the holding section 2, the load cell 5, and the first support section 40.

[0032] The guide unit 50 includes carriages 51, 52, which are movable parts, and a rail 53 that movably supports the carriages 51, 52 (see FIG. 4). The holding unit 2, the load cell 5, and the first support unit 40 are configured to be able to move integrally on the rail 53 via the carriages 51, 52. The example in FIG. 4 shows that the holding unit 2 on the north side is supported by one of the two carriages 51, 52 (the carriage 51 on the -Y side), and the first support unit 40 on the north side is supported by the other of the two carriages 51, 52 (the carriage 52 on the +Y side).

[0033] In this embodiment, the multiple guide units 50 are each configured with the same linear guide. Note that at least some of the multiple guide units 50 may be configured with different linear guides, or may be configured with a guide mechanism different from the linear guide. For example, the configuration of the multiple guide units 50 can be changed according to design specifications.

[0034] <Pantograph mechanism> The biaxial tensile tester 1 further includes a pantograph mechanism 60 connected to a plurality of first support parts 40 arranged separately in four directions. The pantograph mechanism 60 includes a parallel link mechanism and is configured so that a diamond-shaped portion in a plan view can be contracted. The first support part 40 includes a trapezoidal portion 43 that is trapezoidal in a plan view and protrudes outward from a plate-like horizontal portion along the horizontal plane (see FIG. 4). The pantograph mechanism 60 is attached to the trapezoidal portion 43 of each first support part 40 so as to be rotatable about an axis along the vertical direction. The pantograph mechanism 60 is attached to the center of the table 11 so as to be rotatable about an axis along the vertical direction.

[0035] A pair of pantograph mechanisms 60 are provided to connect the north and south first support parts 40 and the east and west first support parts 40. The example in Fig. 4 shows a state in which one pantograph mechanism 60 is connected to the north first support part 40. The pantograph mechanism 60 can generate linear displacements in two opposing directions evenly around the center of the test piece.

[0036] <Base plate> The biaxial tensile testing machine 1 further includes a base plate 6 that supports the guide portion 50 (see FIG. 3). The base plate 6 has a rectangular plate shape in a plan view. The base plate 6 is formed with a plurality of mounting holes 7 to which the second support portion 70 can be detachably attached at positions that do not overlap with the guide portion 50 in a plan view. The base plate 6 is fixed to a base 101 via fastening members such as bolts.

[0037] <Second support part> The biaxial tensile tester 1 further includes a second support portion 70 that supports a second pulley 30 (pulleys 30-8, 30-10, 30-20, and 30-22 shown in FIG. 2 in this embodiment) that is disposed at a position different from the first pulley 30 among the multiple pulleys 30. In the example of FIG. 4, two second support portions 70 are provided at positions that do not overlap with the guide portion 50 in a plan view. In the example of FIG. 4, the second support portion 70 is formed in a rectangular block shape. The upper center of the second support portion 70 is the portion to which the second pulley 30 is attached.

[0038] The corners of the second support part 70 are portions that are fixed to the base plate 6 via fastening members such as bolts. For example, the second support part 70 can be fixed to the base plate 6 by inserting a bolt into a through hole in the corner of the second support part 70 and screwing the male threaded part of the bolt into the mounting hole 7 (female threaded part) of the bail plate. Note that the configuration of the second support part 70 is not limited to the above and can be changed according to design specifications.

[0039] <Superstructure> The biaxial tensile testing machine 1 includes an upper structure 80 that is attached to the upper part of the uniaxial tensile testing machine 100 (see FIG. 2). The upper structure 80 is a structure attached to the crosshead 103 on the crosshead 103 side. The upper structure 80 includes an upper plate 81 that extends along the crosshead 103, and a plurality of upper support parts 82 that are separately attached to both ends of the upper plate 81 in the extension direction.

[0040] The upper plate 81 is fixed to the lower part of the crosshead 103 via fastening members such as bolts. Four upper pulleys 30 (one example of a second pulley; in this embodiment, pulleys 30-1, 30-5, 30-13, and 30-17 shown in FIG. 2) configured to be rotatable around axes along the X direction are provided on the crosshead 103 side. Four upper support parts 82 are provided corresponding to the four upper pulleys 30. In the example shown in the figure, two upper support parts 82 (four in total) are provided on each end of the extension direction of the upper plate 81.

[0041] In the illustrated example, upper support part 82 is formed in an L-shaped block shape including a plate-shaped horizontal part along the horizontal plane and a plate-shaped vertical part along the vertical plane. The horizontal part of upper support part 82 is a part that is fixed to the end of upper plate 81 in the extension direction. The vertical part of upper support part 82 is a part that supports upper pulley 30. Note that the configuration of upper support part 82 is not limited to the above and can be changed according to design specifications.

[0042] The biaxial tensile testing machine 1 includes a lower structure 90 that is attached to the lower part of the uniaxial tensile testing machine 100 (see FIG. 2). The lower structure 90 is a structure attached to the base plate 6 on the side of the base plate 6. The lower structure 90 includes the above-mentioned holding part 2, load cell 5, connection part 3, etc., as well as a plurality of lower support parts 91, 92, 93 that are arranged on both ends in the X direction.

[0043] In addition to the pulleys 30 described above, twelve lower pulleys 30 (an example of the second pulleys, in this embodiment, pulleys 30-2, 30-4, 30-6, 30-7, 30-11, 30-12, 30-14, 30-16, 30-18, 30-19, 30-23, and 30-24 shown in FIG. 2) are provided on the base plate 6 side. The twelve lower pulleys 30 include four lower pulleys 30 (pulleys 30-6, 30-12, 30-18, and 30-24 shown in FIG. 2 in this embodiment) configured to be rotatable around an axis along the X direction, four lower pulleys 30 (pulleys 30-2, 30-4, 30-14, and 30-16 shown in FIG. 2 in this embodiment) configured to be rotatable around an axis along the Y direction, and four lower pulleys 30 (pulleys 30-7, 30-11, 30-19, and 30-23 shown in FIG. 2 in this embodiment) configured to be rotatable around an axis along the vertical direction. The lower support parts 91, 92, and 93 are provided in a plurality of units corresponding to the twelve lower pulleys 30. In this embodiment, ten lower support parts 91, 92, and 93 are provided.

[0044] In the example shown in the figure, the ten lower support parts 91, 92, 93 include four lower support parts 91 (hereinafter also referred to as "middle support parts 91") corresponding to the four lower pulleys 30 (pulleys 30-6, 30-12, 30-18, 30-24 shown in FIG. 2 in this embodiment) configured to be rotatable around an axis along the X direction, two lower support parts 92 (hereinafter also referred to as "central support parts 92") having four support parts corresponding to the four lower pulleys 30 (pulleys 30-2, 30-4, 30-14, 30-16 shown in FIG. 2 in this embodiment) configured to be rotatable around an axis along the Y direction, and four lower support parts 93 (hereinafter also referred to as "corner support parts 93") corresponding to the four lower pulleys 30 (pulleys 30-7, 30-11, 30-19, 30-23 shown in FIG. 2 in this embodiment) configured to be rotatable around an axis along the vertical direction.

[0045] The intermediate support portion 91 is disposed between the central support portion 92 and the corner support portion 93. In the illustrated example, the intermediate support portion 91 is formed in an L-shaped block shape including a plate-shaped horizontal portion along the horizontal plane and a plate-shaped vertical portion along the vertical plane. The horizontal portion of the intermediate support portion 91 is fixed to the base plate 6 via a fastening member such as a bolt. The vertical portion of the intermediate support portion 91 is a portion that supports the lower pulley 30 (pulleys 30-6, 30-12, 30-18, and 30-24 shown in FIG. 2 in this embodiment). The configuration of the intermediate support portion 91 is not limited to the above and can be changed according to design specifications.

[0046] The central support part 92 is disposed in the center in the Y direction on the base plate 6. In the example shown in the figure, the central support part 92 is formed in a T-shaped block shape including a plate-shaped horizontal part along the horizontal plane and a plate-shaped vertical part along the vertical plane. The horizontal part of the central support part 92 is fixed to the base plate 6 via a fastening member such as a bolt. Two parts on the +Y side and -Y side of the vertical part of the central support part 92 are parts that support the lower pulley 30 (pulleys 30-2, 30-4, 30-14, and 30-16 shown in FIG. 2 in this embodiment). The configuration of the central support part 92 is not limited to the above and can be changed according to design specifications.

[0047] The corner side support portion 93 is disposed on the corner side of the base plate 6. In the example shown in the figure, the corner side support portion 93 is formed in the shape of a rectangular parallelepiped block. The corner portion of the corner side support portion 93 is fixed to the base plate 6 via a fastening member such as a bolt. The upper center of the corner side support portion 93 is a portion that supports the lower pulley 30 (pulleys 30-7, 30-11, 30-19, and 30-23 shown in FIG. 2 in this embodiment). The configuration of the corner side support portion 93 is not limited to the above and can be changed according to design specifications.

[0048] <Arrangement of the erection section (rope)> In this embodiment, four pulleys 30 are provided on the upper structure 80, and twenty pulleys 30 are provided on the lower structure 90, totaling 24 pulleys 30. An example of the arrangement of the rope will be described below, with the pulleys 30 being assigned serial numbers from 1 to 24. In the following example, both ends of the rope are tied between the pulley 30-1 and the pulley 30-24. That is, the rope is stretched from the pulley 30-1 to the pulley 30-24 in that order, with the start point and end point being between the pulley 30-1 and the pulley 30-24 (in this embodiment, point P indicating the start and end points shown in FIG. 2).

[0049] Referring to FIG. 2, the rope extends upward from the starting point P toward pulley 30-1 (corresponding to the upper pulley 30 supported by the upper support portion 82 on the east side and the -Y side). After that, the rope curves along the outer periphery of pulley 30-1, and then extends downward toward pulley 30-2 (corresponding to the lower pulley 30 supported on the -Y side of the central support portion 92 on the east side). After that, the rope curves along the outer periphery of pulley 30-2, and then extends in the -X direction toward pulley 30-3 (corresponding to the first pulley 30 supported by the first support portion 40 on the east side). After that, the rope curves along the outer periphery of pulley 30-3, and then extends in the +X direction toward pulley 30-4 (corresponding to the lower pulley 30 supported on the +Y side of the central support portion 92 on the east side).

[0050] The rope then curves along the outer periphery of pulley 30-4, and then extends upward toward pulley 30-5 (corresponding to upper pulley 30 supported by upper support portion 82 on the east side and +Y side). The rope then curves along the outer periphery of pulley 30-5, and then extends downward toward pulley 30-6 (corresponding to lower pulley 30 supported by intermediate support portion 91 on the east side and +Y side).

[0051] Thereafter, the rope curves along the outer periphery of pulley 30-6, and then extends in the +Y direction toward pulley 30-7 (corresponding to the lower pulley 30 supported by the northeast corner support portion 93). Thereafter, the rope curves along the outer periphery of pulley 30-7, and then extends obliquely in the -X and +Y directions toward pulley 30-8 (corresponding to the second pulley 30 supported by the second support portion 70 on the north and +X side).

[0052] Thereafter, the rope curves along the outer periphery of pulley 30-8, and then extends in the -Y direction toward pulley 30-9 (corresponding to the first pulley 30 supported by the first support portion 40 on the north side). Thereafter, the rope curves along the outer periphery of pulley 30-9, and then extends in the +Y direction toward pulley 30-10 (corresponding to the second pulley 30 supported by the second support portion 70 on the north and -X side).

[0053] Then, the rope curves along the outer periphery of pulley 30-10, and then extends obliquely in the -X and -Y directions toward pulley 30-11 (corresponding to the lower pulley 30 supported by the corner support portion 93 on the northwest side). Then, the rope curves along the outer periphery of pulley 30-11, and then extends in the -Y direction toward pulley 30-12 (corresponding to the lower pulley 30 supported by the intermediate support portion 91 on the west side and +Y side).

[0054] The rope then curves along the outer periphery of pulley 30-12, and then extends upward toward pulley 30-13 (corresponding to the upper pulley 30 supported by the upper support portion 82 on the west side and the +Y side). The rope then curves along the outer periphery of pulley 30-13, and then extends downward toward pulley 30-14 (corresponding to the lower pulley 30 supported on the +Y side of the west central support portion 92).

[0055] Thereafter, the rope curves along the outer periphery of pulley 30-14, and then extends in the +X direction toward pulley 30-15 (corresponding to the first pulley 30 supported by the first support portion 40 on the west side). Thereafter, the rope curves along the outer periphery of pulley 30-15, and then extends in the -X direction toward pulley 30-16 (corresponding to the lower pulley 30 supported on the -Y side of the central support portion 92 on the west side).

[0056] The rope then curves along the outer periphery of pulley 30-16, and then extends upward toward pulley 30-17 (corresponding to the upper pulley 30 supported by the upper support portion 82 on the west side and the -Y side). The rope then curves along the outer periphery of pulley 30-17, and then extends downward toward pulley 30-18 (corresponding to the lower pulley 30 supported by the intermediate support portion 91 on the west side and the -Y side).

[0057] Then, the rope curves along the outer periphery of pulley 30-18, and then extends in the -Y direction toward pulley 30-19 (corresponding to the lower pulley 30 supported by the southwest corner support portion 93). Then, the rope extends obliquely in the +X and -Y directions toward pulley 30-20 (corresponding to the second pulley 30 supported by the second support portion 70 on the south and -X side).

[0058] Thereafter, the rope curves along the outer periphery of pulley 30-20, and then extends in the +Y direction toward pulley 30-21 (corresponding to the first pulley 30 supported by the first support portion 40 on the south side). Thereafter, the rope curves along the outer periphery of pulley 30-21, and then extends in the -Y direction toward pulley 30-22 (corresponding to the second pulley 30 supported by the second support portion 70 on the south and +X side).

[0059] The rope then curves along the outer periphery of pulley 30-22, and then extends obliquely in the +X and +Y directions toward pulley 30-23 (corresponding to the lower pulley 30 supported by the corner support portion 93 on the southeast side). The rope then curves along the outer periphery of pulley 30-23, and then extends in the +Y direction toward pulley 30-24 (corresponding to the lower pulley 30 supported by the east and -Y side intermediate support portion 91).

[0060] Thereafter, the rope curves along the outer circumference of pulley 30-24, and then extends partway upward toward pulley 30-1 (between pulley 30-1 and pulley 30-24). The rope is formed into a loop by tying ends of the rope together between pulley 30-1 and pulley 30-24 (an example of a predetermined position). In this embodiment, the rope travels up and down, in the X-direction, the Y-direction, and diagonally from the start point to the end point between pulley 30-1 and pulley 30-24, thereby forming a loop. A tensile force is applied to the rope when crosshead 103 is raised.

[0061] In this embodiment, the portion of the installation part 4 that is hung across the pulleys 30, the load cell 5, and the holding part 2 are arranged coaxially in four directions. In the example shown in the figure, the portions of the rope that are hung across the first pulley 30 (pulleys 30-3, 30-9, 30-15, and 30-21 shown in FIG. 2 in this embodiment) and split into two are parallel to each other and arranged coaxially with the center lines of the load cell 5 and the holding part 2 when viewed from the side (horizontally).

[0062] <Example of load ratio setting> Fig. 5 is a plan view showing a first setting example of the load ratio of the biaxial tensile tester 1 according to the first embodiment. Fig. 6 is a plan view showing a second setting example of the load ratio of the biaxial tensile tester 1 according to the first embodiment. Fig. 7 is a plan view showing a third setting example of the load ratio of the biaxial tensile tester 1 according to the first embodiment. Fig. 8 is a plan view showing a fourth setting example of the load ratio of the biaxial tensile tester 1 according to the first embodiment. 5 to 8, the direction along the first axis, which is one of the two axes, is defined as the first axis direction (X direction), and the direction along the second axis, which is the other of the two axes, is defined as the second axis direction (Y direction). When a load is applied to the test piece 10, a part of the first axis direction in the installation part 4 extends parallel to the tensile direction of the test piece 10, and a part of the second axis direction in the installation part 4 extends at an angle θ with respect to the first axis direction. The ratio Fx:Fy of the load Fx in the first axis direction to the load Fy in the second axis direction is expressed as Fx:Fy=1:sinθ.

[0063] 5 is an example in which the angle θ is about 90°. In this case, the ratio Fx:Fy is substantially expressed as Fx:Fy=1:1. 6 is an example in which the angle θ is about 30°. In this case, the ratio Fx:Fy is substantially expressed as Fx:Fy=2:1. 7 is an example in which the angle θ is about 14.7°. In this case, the ratio Fx:Fy is substantially expressed as Fx:Fy=4:1. 8 is an example in which the angle θ is about 48°. In this case, the ratio Fx:Fy is substantially expressed as Fx:Fy=4:3. In this way, various load ratios can be easily set by the relationship expressed by Fx:Fy=1:sin θ.

[0064] <Action and effect> As described above, the biaxial tensile tester 1 of this embodiment is a biaxial tensile tester that pulls the test piece 10 along two mutually perpendicular four directions. The biaxial tensile tester 1 includes a plurality of holding parts 2 that respectively hold the four portions of the test piece 10, a plurality of connecting parts 3 that are respectively connected to the plurality of holding parts 2, and a bridging part 4 that is bridged in a loop shape across the plurality of connecting parts 3. According to this configuration, when the bridging portion 4 is bridged around the multiple connecting portions 3 in a loop shape and a tensile force is generated in the four directions of the test piece 10 by the tension of the bridging portion 4, the tension becomes constant around one revolution. That is, the tension of the bridging portion 4 becomes constant at any position. In addition, since no new driving source is required, it is inexpensive. Therefore, it is possible to provide a biaxial tensile tester 1 that can perform tests at a constant load ratio and is inexpensive and simple to use.

[0065] In this embodiment, the angle at which the bridging portion 4 is bridged across the multiple connection portions 3 can be changed to any angle. According to this configuration, by arbitrarily changing the position at which the bridging portion 4 is bridged over the multiple connection portions 3, tests with various load ratios can be performed.

[0066] In this embodiment, the direction along the first axis, which is one of the two axes, is defined as the first axis direction, and the direction along the second axis, which is the other of the two axes, is defined as the second axis direction. When a load is applied to the test piece 10, a part of the first axis direction in the installation part 4 extends parallel to the tensile direction of the test piece 10, and a part of the second axis direction in the installation part 4 extends at an angle θ with respect to the first axis direction. The ratio Fx:Fy of the load Fx in the first axis direction to the load Fy in the second axis direction is expressed as Fx:Fy=1:sinθ. According to this configuration, various load ratios can be easily set due to the relationship expressed by Fx:Fy=1:sin θ.

[0067] In this embodiment, the biaxial tensile tester 1 further includes a plurality of load cells 5 respectively connected to the plurality of holding parts 2. The holding parts 2, the load cells 5, and the connection parts 3 are arranged in this order from the center in the four directions. According to this configuration, by arranging the holding portion 2, the load cell 5, and the connection portion 3 in this order from the center in all four directions, it is possible to realize a compact arrangement in all four directions.

[0068] In this embodiment, each of the multiple connection parts 3 includes multiple pulleys 30, around which the installation part 4 is spanned, at a position opposite to the holding part 2 with the load cell 5 in between. According to this configuration, the bridging portion 4 is spanned across a plurality of pulleys 30, so that the tension of the bridging portion 4 can be applied smoothly.

[0069] In this embodiment, the portion of the installation part 4 that is suspended across the pulleys 30, the load cell 5, and the holding part 2 are coaxially arranged in four directions. With this configuration, tensile forces can be stably generated in all four directions of the test piece 10 compared to a case in which the portion of the installation section 4 that is suspended across multiple pulleys 30, the load cell 5, and the holding section 2 are arranged on different axes in all four directions.

[0070] In this embodiment, the biaxial tensile testing machine 1 further includes a first support portion 40 that supports the first pulley 30 that is positioned closest to the load cell 5 among the multiple pulleys 30, and a guide portion 50 that guides the holding portion 2 and the first support portion 40 in a straight line in four directions. According to this configuration, the holding portion 2 and the first support portion 40 are guided in a straight line in four directions by the guide portion 50, so that tensile forces can be generated in the four directions of the test piece 10 more stably.

[0071] In this embodiment, the biaxial tensile tester 1 further includes a pantograph mechanism 60 connected to a plurality of first support parts 40 respectively arranged in four directions. According to this configuration, the pantograph mechanism 60 can ensure equal displacement of the two sets of holding parts 2 facing each other.

[0072] In this embodiment, the biaxial tensile tester 1 further includes a base plate 6 that supports the guide portion 50 . According to this configuration, the guide portion 50 is supported by the base plate 6, so that tensile forces can be generated in the four directions of the test piece 10 more stably.

[0073] In this embodiment, the biaxial tensile tester 1 further includes a second support portion 70 that supports a second pulley 30, which is disposed at a position different from the first pulley 30, among the multiple pulleys 30. The base plate 6 is formed with a plurality of mounting holes 7, into which the second support portion 70 can be detachably attached, at positions that do not overlap with the guide portion 50 in a plan view. According to this configuration, by attaching the second support portion 70 to any of the multiple mounting holes 7, tests with various load ratios can be easily performed.

[0074] In this embodiment, the installation portion 4 is a rope. According to this configuration, a loop-shaped spanning configuration can be easily realized.

[0075] <Second embodiment> Fig. 9 is a side view of the biaxial tensile tester 201 according to the second embodiment. Fig. 10 is a plan view of the biaxial tensile tester 201 according to the second embodiment. In Fig. 10, the crosshead 103 and the like are omitted. Hereinafter, a biaxial tensile tester 201 according to the second embodiment will be described with reference to Figures 9 and 10. In the configuration shown in Figures 9 and 10, the same components as those in the above-mentioned embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0076] The biaxial tensile tester 201 includes a plurality of holding parts 2 that respectively hold the four portions of the test piece 10 in each of the four directions, a plurality of load cells 5 that are respectively connected to the plurality of holding parts 2, a plurality of connection parts 3 that are respectively connected to the plurality of holding parts 2 and have a plurality of pulleys 30, a bridge part 4 that is suspended in a loop shape around the plurality of pulleys 30, and a first pulley 30 (pulleys 30-6, 30- The pulley 30 includes a first support section 40 supporting a first pulley 30 (pulleys 30-4, 30-5, 30-7, 30-8, 30-10, 30-11, 30-13, 30-14 shown in FIG. 10 in this embodiment) that is arranged at a position different from the first pulley 30 among the plurality of pulleys 30. In this embodiment, the second support section 270 extends along each side of the base plate 6 that is rectangular in plan view.

[0077] The biaxial tensile tester 201 includes an upper structure 280 on the crosshead 103 side that is assembled to the crosshead 103. The upper structure 280 includes a plurality of upper support parts 281 that are attached to the center side of the crosshead 103 in the extension direction. On the crosshead 103 side, two upper pulleys 30 (an example of the second pulley 30; in this embodiment, pulleys 30-2 and 30-16 shown in FIG. 10) that are configured to be rotatable around axes along the Y direction are provided. Two upper support parts 281 are provided corresponding to the two upper pulleys 30.

[0078] The biaxial tensile tester 201 includes a lower structure 290 that is attached to each of the base 101 that constitutes the lower part of the uniaxial tensile tester 100 and the base plate 6 that constitutes the biaxial tensile tester 201. The lower structure 290 includes the above-mentioned holding unit 2, the load cell 5, the connection unit 3, and the like, as well as a plurality of lower support units 291 that are attached to the base 101. On the side of the base 101, four lower pulleys 30 (an example of the second pulley 30; in this embodiment, pulleys 30-1, 30-3, 30-15, and 30-17 shown in FIG. 10) that are configured to be rotatable around axes along the X direction are provided. Four lower support units 291 are provided corresponding to the four lower pulleys 30.

[0079] In this embodiment, a total of 18 pulleys 30 are provided in the upper structure 280 (crosshead 103 side), and 16 pulleys 30 are provided in the lower structure 290 (base 101 and base plate 6 side). An example of the arrangement of the rope will be described below, with the pulleys 30 being assigned serial numbers from 1 to 18. In the following example, both ends of the rope are tied between pulley 30-1 and pulley 30-18. That is, the rope is stretched from pulley 30-1 to pulley 30-18 in that order, with the start point and end point being between pulley 30-1 and pulley 30-18 (points P indicating the start and end points shown in FIG. 10 in this embodiment).

[0080] Referring to FIG. 10, the rope extends in the +Y direction from the starting point P toward pulley 30-1 (corresponding to the lower pulley 30 supported by the lower support portion 291 on the northeast side and the -X side). After that, the rope curves along the outer periphery of pulley 30-1, and then extends upward toward pulley 30-2 (corresponding to the upper pulley 30 supported by the upper support portion 281 on the northeast side). After that, the rope curves along the outer periphery of pulley 30-2, and then extends downward toward pulley 30-3 (corresponding to the lower pulley 30 supported by the lower support portion 291 on the northeast side and the +X side). After that, the rope curves along the outer periphery of pulley 30-3, and then extends in the -Y direction toward pulley 30-4 (corresponding to the second pulley 30 supported on the +X side of the second support portion 270 on the north side).

[0081] Thereafter, the rope curves along the outer periphery of pulley 30-4, and then extends obliquely in the +X and -Y directions toward pulley 30-5 (corresponding to the second pulley 30 supported on the +Y side of the east-side second support portion 270). Thereafter, the rope curves along the outer periphery of pulley 30-5, and then extends obliquely in the -X and -Y directions toward pulley 30-6 (corresponding to the first pulley 30 supported by the east-side first support portion 40).

[0082] Thereafter, the rope curves along the outer periphery of pulley 30-6, and then extends obliquely in the +X and -Y directions toward pulley 30-7 (corresponding to the second pulley 30 supported on the -Y side of the east-side second support portion 270). Thereafter, the rope curves along the outer periphery of pulley 30-7, and then extends obliquely in the -X and -Y directions toward pulley 30-8 (corresponding to the second pulley 30 supported on the +X side of the south-side second support portion 270).

[0083] Thereafter, the rope curves along the outer periphery of pulley 30-8, and then extends in the +Y direction toward pulley 30-9 (corresponding to the first pulley 30 supported by the south-side first support portion 40). Thereafter, the rope curves along the outer periphery of pulley 30-9, and then extends in the -Y direction toward pulley 30-10 (corresponding to the second pulley 30 supported on the -X side of the south-side second support portion 270).

[0084] Thereafter, the rope curves along the outer periphery of pulley 30-10, and then extends obliquely in the -X and +Y directions toward pulley 30-11 (corresponding to the second pulley 30 supported on the -Y side of the western second support portion 270). Thereafter, the rope curves along the outer periphery of pulley 30-11, and then extends obliquely in the +X and +Y directions toward pulley 30-12 (corresponding to the first pulley 30 supported by the western first support portion 40).

[0085] Thereafter, the rope curves along the outer periphery of pulley 30-12, and then extends obliquely in the -X and +Y directions toward pulley 30-13 (corresponding to the second pulley 30 supported on the +Y side of the west-side second support portion 270). Thereafter, the rope curves along the outer periphery of pulley 30-13, and then extends obliquely in the +X and +Y directions toward pulley 30-14 (corresponding to the second pulley 30 supported on the -X side of the north-side second support portion 270).

[0086] Thereafter, the rope curves along the outer periphery of pulley 30-14, and then extends in the +Y direction toward pulley 30-15 (corresponding to the lower pulley 30 supported by the lower support portion 291 on the northwest side and the -X side). Thereafter, the rope curves along the outer periphery of pulley 30-15, and then extends upward toward pulley 30-16 (corresponding to the upper pulley 30 supported by the upper support portion 281 on the northwest side).

[0087] The rope then curves around the outer periphery of pulley 30-16, and then extends downward toward pulley 30-17 (corresponding to the lower pulley 30 supported by the lower support portion 291 on the northwestern + side). The rope then curves around the outer periphery of pulley 30-17, and then extends downward toward pulley 30-18 (corresponding to the first pulley 30 supported by the first support portion 40 on the north side).

[0088] Thereafter, the rope curves along the outer circumference of pulley 30-18, and then extends partway in the +Y direction toward pulley 30-1 (between pulley 30-1 and pulley 30-18). The rope is formed into a loop by tying ends of the rope together between pulley 30-1 and pulley 30-18 (an example of a predetermined position). In this embodiment, the rope travels up and down, in the X and Y directions, and diagonally from the start point to the end point between pulley 30-1 and pulley 30-18, thereby forming a loop. A tensile force is applied to the rope when crosshead 103 is raised.

[0089] As described above, according to the configuration of the biaxial tensile tester 201 of this embodiment, the bridging portion 4 is suspended in a loop shape around the multiple connection portions 3, so that when a tensile force is generated in the four directions of the test piece 10 by the tension of the bridging portion 4, the tension becomes constant around one revolution. That is, the tension of the bridging portion 4 becomes constant at any position. In addition, since no new driving source is required, it is inexpensive. Therefore, it is possible to provide a biaxial tensile tester 201 that can perform a test at a constant load ratio and is inexpensive and simple to use.

[0090] According to the embodiment described above, the direction of tension applied to the rope can be freely changed via the pulley 30. Therefore, by forming one loop by hanging the rope around multiple pulleys 30, it is possible to ensure that uniform tension is applied at all locations. In addition, by incorporating the biaxial tensile tester 1,201 according to the embodiment into a general-purpose uniaxial tensile tester 100, it is not necessary to prepare a new drive source. Furthermore, the tensile force applied to the shaft can be freely changed in a stepless manner depending on the angle θ of the rope hung around the pulley 30. As described above, according to the embodiment, a uniform tension is guaranteed by the tension load on a single rope in a loop state, and the tension ratio can be changed in a stepless manner depending on the winding angle around the loop (the installation position of the pulley 30). In addition, since the displacement ratio is not constant, unlike the conventional simplified biaxial tensile tester, an appropriate biaxial stress test can be performed. Furthermore, since it can be incorporated into a general-purpose tensile tester, no new capital investment is required.

[0091] <Modification> In the above-described embodiment, an example has been described in which the angle at which the bridging portion is bridged over the multiple connection parts can be changed to any angle, but this is not limited thereto. For example, the angle at which the bridging portion is bridged over the multiple connection parts may be fixed to a predetermined angle. For example, at least a part of the position at which the bridging portion is bridged over the multiple connection parts may be fixed to a fixed position. For example, the angle and position at which the bridging portion is bridged over the multiple connection parts can be changed according to the design specifications.

[0092] In the above-mentioned embodiment, the direction along the first axis of one of the two axes is the first axis direction, and the direction along the second axis of the other of the two axes is the second axis direction, and when a load is applied to the test piece, a part of the first axis direction in the installation part extends parallel to the tensile direction of the test piece, and a part of the second axis direction in the installation part extends at an angle θ with respect to the first axis direction, and the ratio Fx:Fy of the load Fx in the first axis direction to the load Fy in the second axis direction is expressed by Fx:Fy=1:sinθ. However, the present invention is not limited to this. For example, the setting mode of the load ratio of the biaxial tensile tester (for example, a relationship such as a mathematical formula) can be changed according to the design specifications.

[0093] In the above-mentioned embodiment, the biaxial tensile tester further includes a plurality of load cells respectively connected to a plurality of holding parts, and is described as being arranged in the order of the holding parts, the load cells, and the connection parts from the center in the four directions, but is not limited thereto. For example, other members may be arranged between the holding parts and the load cells and / or between the load cells and the connection parts.

[0094] In the above-described embodiment, an example has been described in which each of the multiple connection parts includes multiple pulleys on which the bridging parts are hung at a position opposite to the holding part across the load cell, but this is not limited thereto. For example, each of the multiple connection parts may include a pin instead of at least a part of the multiple pulleys, or together with the pulleys. For example, the member on which the bridging parts are hung may be a rotating body other than a pulley. If more strength is required, the bridging parts may be metal chains, and the pulleys may be sprockets. For example, the manner in which the bridging parts are hung can be changed according to design specifications.

[0095] In the above-described embodiment, an example has been described in which the portion of the installation part that is hung across multiple pulleys, the load cell, and the holding part are arranged on the same axis in four directions, but this is not limited thereto. For example, the portion of the installation part that is hung across multiple pulleys, the load cell, and the holding part may be arranged on different axes in the four directions. For example, the arrangement of the portion of the installation part that is hung across multiple pulleys, the load cell, and the holding part may be changed according to the design specifications.

[0096] In the above-mentioned embodiment, the biaxial tensile tester is described as further including a first support part that supports a first pulley that is located closest to the load cell among the multiple pulleys, and a guide part that guides the holding part and the first support part in a straight line in four directions, but is not limited thereto. For example, the biaxial tensile tester does not need to include a guide part. For example, the installation mode of the guide part can be changed according to the design specifications.

[0097] In the above-mentioned embodiment, the biaxial tensile tester is described as further including a pantograph mechanism connected to a plurality of first support parts arranged in four directions, but is not limited thereto. For example, the biaxial tensile tester does not need to include a pantograph mechanism. For example, the installation mode of the pantograph mechanism can be changed according to the design specifications.

[0098] In the above-described embodiment, the biaxial tensile tester is described as further including a base plate that supports the guide portion, but the present invention is not limited thereto. For example, the biaxial tensile tester may not include a base plate. For example, the guide portion may be supported by a base of the uniaxial tensile tester. For example, the installation mode of the base plate may be changed according to the design specifications.

[0099] In the above-mentioned embodiment, the biaxial tensile tester further includes a second support part for supporting a second pulley, which is disposed at a position different from the first pulley, among the plurality of pulleys, and a plurality of mounting holes are formed in the base plate, in a position that does not overlap with the guide part in a plan view, to which the second support part can be detachably attached, but the present invention is not limited to this. For example, the base plate may have a plurality of pulleys attached thereto. For example, the base plate may have pins instead of at least a part of the plurality of mounting holes, or in addition to the mounting holes. For example, the base plate may be configured to be capable of performing tests with various load ratios by bridging the bridging part across the pulleys and / or pins at any position among the plurality of pulleys and / or pins. For example, the configuration for performing tests with various load ratios may be changed according to the design specifications.

[0100] In the present embodiment, the installation part is described as a rope by way of example, but is not limited thereto. For example, the installation part may be a member other than a rope, such as a cable or a chain. For example, the installation part may be made of a member that is flexible and can withstand the test load (maximum load). For example, the configuration of the installation part may be changed according to the design specifications.

[0101] Although the embodiments of the present invention have been described above, the present invention is not limited to these, and additions, omissions, substitutions, and other modifications of the configuration are possible without departing from the spirit of the present invention, and the above-described embodiments can also be combined as appropriate.

[0102] (Appendix 1) A biaxial tensile testing machine that pulls a test piece along four directions of two mutually perpendicular axes, A plurality of holding portions each holding a portion of the test piece in each of the four directions; A plurality of connection parts respectively connected to the plurality of holding parts; A bridge portion that is bridged in a loop shape over the multiple connection portions. Biaxial tensile testing machine.

[0103] (Appendix 2) The angle at which the bridging portion is bridged over the multiple connection portions can be changed to any angle. A biaxial tensile testing machine as described in Appendix 1.

[0104] (Appendix 3) one of the two axes is a first axis direction and the other of the two axes is a second axis direction, and when a load is applied to the test piece, a part of the first axis direction in the mounting portion extends parallel to a tensile direction of the test piece, and a part of the second axis direction in the mounting portion extends at an angle θ with respect to the first axis direction, The ratio Fx:Fy of the load Fx in the first axial direction to the load Fy in the second axial direction is Fx:Fy=1:sinθ 3. A biaxial tensile testing machine according to claim 1 or 2.

[0105] (Appendix 4) Further comprising a plurality of load cells respectively connected to the plurality of holding portions, The holding portion, the load cell, and the connection portion are arranged in this order from the center in the four directions. 4. A biaxial tensile testing machine according to any one of claims 1 to 3.

[0106] (Appendix 5) Each of the plurality of connection parts includes a plurality of pulleys around which the installation part is hung, the pulleys being disposed on the opposite side of the load cell from the holding part. A biaxial tensile testing machine as described in Appendix 4.

[0107] (Appendix 6) The portion of the bridge portion that is bridged across the pulleys, the load cell, and the holding portion are coaxially arranged in the four directions. A biaxial tensile testing machine as described in Appendix 5.

[0108] (Appendix 7) a first support portion that supports a first pulley that is disposed at a position closest to the load cell among the plurality of pulleys; A guide portion that guides the holding portion and the first support portion in a straight line in the four directions, A biaxial tensile testing machine as described in Appendix 6.

[0109] (Appendix 8) Further comprising a pantograph mechanism connected to a plurality of the first support parts respectively arranged in the four directions, A biaxial tensile testing machine as described in Appendix 7.

[0110] (Appendix 9) Further comprising a base plate supporting the guide portion. 9. A biaxial tensile testing machine according to claim 7 or 8.

[0111] (Appendix 10) a second support portion for supporting a second pulley among the plurality of pulleys, the second pulley being disposed at a position different from the first pulley; The base plate is formed with a plurality of mounting holes to which the second support portion can be detachably attached at positions that do not overlap with the guide portion in a plan view. Attachment 9: A biaxial tensile testing machine.

[0112] (Appendix 11) The installation part is a rope. 11. A biaxial tensile testing machine according to any one of claims 1 to 10. EXAMPLES

[0113] The biaxial tensile tester according to the embodiment of the present invention will be specifically described below with reference to examples. Note that the following examples are specific examples to which the present invention is applied, and are not intended to limit the present invention.

[0114] Fig. 11 is an explanatory diagram of the results of the constant load ratio preliminary test of Examples 1-4. In Fig. 11, the vertical axis indicates the average load Fx in the X direction, and the horizontal axis indicates the average load Fy in the Y direction. In Fig. 11, the load Fx in the directions of the arrows acting on the cross test piece is E is the load on one side (east side) in the X direction, F W is the load on the other side (west side) in the X direction, F N is the load in the Y direction (north side), F Sindicates the load on the other side (south side) in the Y direction, respectively.

[0115] (Examples 1 to 4) The constant load ratio preliminary tests of Examples 1-4 were carried out using the biaxial tensile tester 1 according to the above-described first embodiment (see Figs. 1 to 4). In Example 1, the load ratio was Fx:Fy=1:1, in Example 2, the load ratio was Fx:Fy=4:3, in Example 3, the load ratio was Fx:Fy=2:1, and in Example 4, the load ratio was Fx:Fy=4:1.

[0116] (Evaluation Results) In each of Examples 1 to 4, a maximum load of 1 kN was set, and biaxial tensile force was applied to the cross specimen to confirm whether the set load ratio could be achieved. As shown in Fig. 11, it was confirmed that the planned design values ​​and the experimental values ​​were generally consistent. As a result, it was confirmed that the developed biaxial tensile testing machine can perform tests with a set load ratio (tests with a constant load ratio). [Explanation of symbols]

[0117] 1...Biaxial tensile testing machine, 2...Holding part, 3...Connection part, 4...Installation part, 5...Load cell, 6...Base plate, 7...Mounting hole, 10...Test piece, 30...Pulley, 40...First support part, 50...Guide part, 60...Pantograph mechanism, 70...Second support part, 201...Biaxial tensile testing machine, 270...Second support part

Claims

1. A biaxial tensile testing machine that pulls a test piece along four directions of two mutually perpendicular axes, A plurality of holding portions each holding a portion of the test piece in each of the four directions; A plurality of connection parts respectively connected to the plurality of holding parts; A bridge portion that is bridged in a loop shape over the multiple connection portions. Biaxial tensile testing machine.

2. The angle at which the bridging portion is bridged over the multiple connection portions can be changed to any angle. The biaxial tensile testing machine according to claim 1.

3. a direction along a first axis of one of the two axes is defined as a first axis direction, and a direction along a second axis of the other of the two axes is defined as a second axis direction, and when a load is applied to the test piece, a part of the first axis direction in the mounting portion extends parallel to a tensile direction of the test piece, and a part of the second axis direction in the mounting portion extends at an angle θ with respect to the first axis direction, The ratio Fx:Fy of the load Fx in the first axial direction to the load Fy in the second axial direction is Fx:Fy=1:sinθ, The biaxial tensile testing machine according to claim 1 or 2.

4. Further comprising a plurality of load cells respectively connected to the plurality of holding portions, The holding portion, the load cell, and the connection portion are arranged in this order from the center in the four directions. The biaxial tensile testing machine according to claim 1 or 2.

5. Each of the plurality of connection parts includes a plurality of pulleys around which the installation part is hung, the pulleys being disposed on the opposite side of the load cell from the holding part. The biaxial tensile testing machine according to claim 4.

6. The portion of the bridge portion that is bridged across the pulleys, the load cell, and the holding portion are coaxially arranged in the four directions. The biaxial tensile testing machine according to claim 5.

7. a first support portion that supports a first pulley that is disposed at a position closest to the load cell among the plurality of pulleys; A guide portion that guides the holding portion and the first support portion in a straight line in the four directions. The biaxial tensile testing machine according to claim 6.

8. Further, a pantograph mechanism is provided which is connected to a plurality of the first support parts which are respectively arranged in the four directions. The biaxial tensile testing machine according to claim 7.

9. Further comprising a base plate supporting the guide portion. The biaxial tensile testing machine according to claim 7.

10. a second support portion for supporting a second pulley among the plurality of pulleys, the second pulley being disposed at a position different from the first pulley; The base plate is formed with a plurality of mounting holes to which the second support portion can be detachably attached at positions that do not overlap with the guide portion in a plan view. The biaxial tensile testing machine according to claim 9.

11. The installation part is a rope. The biaxial tensile testing machine according to claim 1 or 2.

Images