Material testing machine

Abstract

The invention provides a material testing machine which can prevent the front end part of a clamp from falling down vertically and does not apply deformation resistance to a sample. A material testing machine grips a sample with three or more jigs arranged substantially horizontally and applies a test force to the sample in a centrosymmetric manner, the material testing machine being provided with a support below the jigs, the support allowing movement of the jigs in a substantially horizontal direction and restricting movement of the jigs in a substantially vertical downward direction.

Description

Technical Field

[0001] This invention relates to a material testing machine. Background Technology

[0002] Patent document 1 discloses a material testing machine that uses multiple clamps arranged in a roughly horizontal manner to clamp the specimen and apply a test force symmetrically to the center of the specimen.

[0003] In the past, in material testing machines such as Patent Document 1, guide rails were sometimes installed below the fixture to prevent the fixture from tipping forward.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Publication No. 2016-515718 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] However, the structure of conventional guide rails can lead to constraints on the fixtures, which may generate resistance during tensile tests.

[0009] The purpose of this invention is to provide a material testing machine that prevents the fixture from tipping forward and does not generate resistance during tensile testing.

[0010] Solution for solving the problem

[0011] One embodiment of the present invention provides a material testing machine that uses three or more clamps arranged in a generally horizontal manner to grip a specimen and apply a test force symmetrically to the center of the specimen. A support member is provided below the clamps, which allows the clamps to move in a generally horizontal direction and restricts the clamps from moving in a generally vertical direction.

[0012] The effects of the invention

[0013] According to a technical solution of the present invention, the clamps of the material testing machine can be prevented from tipping forward, and no resistance is generated during tensile testing. Attached Figure Description

[0014] Figure 1 This is a three-dimensional diagram representing a biaxial tensile testing machine.

[0015] Figure 2 yes Figure 1 Sectional view II-II.

[0016] Figure 3 This is a magnified three-dimensional view of the center of a biaxial tensile testing machine.

[0017] Figure 4 This is a top view of the fixture.

[0018] Figure 5 This is a side view of the fixture.

[0019] Figure 6 This is a three-dimensional diagram representing the test bench.

[0020] Figure 7 This is a three-dimensional view of the support component.

[0021] Figure 8 This is a top view of the support component.

[0022] Figure 9 This is a side view of the support component.

[0023] Explanation of reference numerals in the attached figures

[0024] 1. Biaxial tensile testing machine (material testing machine); 3. Base; 5. Tensile mechanism; 9. Test bench; 11. Lifting unit; 13. Control device; 15. Motor; 15A. Motor shaft; 17. Drive belt; 19. Pulley; 21. Orthogonal force transmission mechanism; 23. Shaft; 25. Shaft support; 25A. Longitudinal plate; 25B. Cylindrical section; 27. Support plate; 29. ​​Ball screw nut; 31. Housing; 33. Block; 35. Track; 41. Fixture; 41X. First fixture; 41Y. Second fixture; 43. Load sensor; 45. Rod; 53. Connecting part; 55. Chuck; 57. Upper chuck; 59. Lower chuck; 61. Support column; 63. Base; 65. Plate; 69. Support component; 169. Side plate; 170. Movable body; 171. Needle-shaped component (rotating component); 173. Protrusion; 174. Fixing hole; 175. Fixing component; S. Space; T. Sample. Detailed Implementation

[0025] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0026] [1. Implementation Method]

[0027] Figure 1 This is a perspective view of the biaxial tensile testing machine 1. Figure 2 yes Figure 1 Sectional view II-II. The biaxial tensile testing machine 1 is an example of a material testing machine.

[0028] The figures show the X, Y, and Z axes of the biaxial tensile testing machine 1. The X and Y axes are orthogonal to each other in the horizontal plane, and the Z axis is a vertical axis that runs along the height of the biaxial tensile testing machine 1.

[0029] The biaxial tensile testing machine 1 stretches a letter X-shaped or cross-shaped specimen T (see reference) in the X-axis and Y-axis directions. Figure 4 The material testing machine is used to perform the test. The specimen T is the test body for the biaxial tensile test. The biaxial tensile test is, for example, the test according to ISO standard 16842.

[0030] like Figure 1 As shown, the biaxial tensile testing machine 1 includes a base 3, a tensile mechanism 5 supported on the base 3, and a test table 9 disposed in the center of the base 3.

[0031] The base 3, which is shaped like the letter X, has multiple lifting parts 11 at its lower part. The height of the base 3 can be adjusted using the lifting parts 11.

[0032] As the tensile mechanism 5, the X-side tensile mechanism 5X, which stretches the specimen T with the same force in the +X and -X directions, and the Y-side tensile mechanism 5Y, which stretches the specimen T with the same force in the +Y and -Y directions, are orthogonally arranged. Although not shown, the biaxial tensile testing machine 1 has an X-side control device for controlling the X-side tensile mechanism 5X and a Y-side control device for controlling the Y-side tensile mechanism 5Y.

[0033] The tensioning mechanism 5 has a motor 15, a transmission belt 17, a pulley 19 and a shaft 23 at one end.

[0034] Figure 2 It is a sectional view obtained by observing a plane that passes through axis 23 extending along the X direction and along the Z direction from the -Y direction toward the +Y direction.

[0035] Reference Figure 2 The pulley 19 has an orthogonal force transmission mechanism 21 at its lower part. The orthogonal force transmission mechanism 21 meshes with the shaft 23. The orthogonal force transmission mechanism 21 is, for example, a worm gear, which meshes with a worm formed on the shaft 23. When the motor shaft 15A is rotated by the motor 15, the pulley 19 rotates by means of the transmission belt 17. The orthogonal force transmission mechanism 21 and the pulley 19 rotate together around the Z-axis, and the shaft 23 rotates simultaneously.

[0036] like Figure 2 As shown, one end of the shaft 23 is supported by a shaft support portion 25 disposed adjacent to the motor 15. The shaft support portion 25 includes a pair of longitudinal plates 25A provided on the base 3 and a cylindrical portion 25B connected between the pair of longitudinal plates 25A, and the shaft 23 is rotatably supported on the cylindrical portion 25B. The other end of the shaft 23 is supported on a support plate 27 provided on the base 3.

[0037] The shaft 23 of the Y-side tensioning mechanism 5Y is positioned above the shaft 23 of the X-side tensioning mechanism 5X, and the two shafts 23 are arranged in a manner that does not cause interference. The X-side tensioning mechanism 5X and the Y-side tensioning mechanism 5Y are arranged offset from each other in a manner that does not cause interference between the shafts 23, but since their structures are the same, they are collectively referred to as tensioning mechanism 5 and will be described as such.

[0038] A pair of ball screw nuts 29 are provided on the shaft 23, and the shaft 23 and the pair of ball screw nuts 29 constitute a so-called ball screw mechanism. As the shaft 23 rotates, the ball screw nut 29 on the motor 15 side and the ball screw nut 29 on the opposite side move along the axis of the shaft 23 in a direction away from each other or in a direction close to each other.

[0039] The ball screw nut 29 is connected to the lower part of the shell-shaped crosshead 31 located on the base 3, and the ball screw nut 29 and the crosshead 31 move as a single unit. The crosshead 31 has a pair of blocks 33 on its lower side, and the blocks 33 engage with the rails 35 assembled on the base 3. The blocks 33 and the rails 35 constitute a so-called guide mechanism. Thus, the crosshead 31 can move axially along the shaft 23 on the base 3.

[0040] A rod 45 extends through the upper part of the crosshead 31. A connecting rod 45A is connected to the rod 45, and a clamp 41 is connected to the front end of the connecting rod 45A.

[0041] The crosshead 31 has a load sensor 43 connected to the rod 45 on the side opposite to the test bench 9. The load sensor 43 is connected to a control device (not shown) to measure the test force, displacement, etc. of the fixture 41.

[0042] like Figure 1 and Figure 2 As shown, rod 45 passes through rod support portion 49, which is disposed adjacent to the test pedestal 9 of crosshead 31 on the base 3. Rod support portion 49 extends upward from base 3 in a plate-like shape, with rod 45 passing through a cylindrical opening in the upper part of rod support portion 49, supporting the load of rod 45. In addition, rod support portion 49 has an opening in the lower part so that shaft 23 can be arranged.

[0043] Next, the clamp 41 installed at the front end of the connecting rod 45A will be described.

[0044] A connecting part 53 is connected to the front end of the connecting rod 45A. The connecting part 53 moves integrally with the crosshead 31 and the rod 45. A clamp 41 is connected to the connecting part 53, which is used to grasp and hold the sample T.

[0045] The rotation of motor 15 causes shaft 23 to rotate, and ball screw nut 29 and crosshead 31 move together, thereby moving clamp 41 at the front end of connecting rod 45A. The tensioning mechanism 5 can stretch specimen T in two coaxial directions using a pair of oppositely configured clamps 41.

[0046] Next, the structure around the test bench 9 will be explained.

[0047] Figure 3 This is an enlarged perspective view of the center of the biaxial tensile testing machine 1. Figure 4 This is a top view showing the test bench 9 and fixture 41 as seen from above. Figure 5 This is a side view showing the clamp 41 and the support 69.

[0048] like Figure 3 As shown, the fixture 41 is divided into upper and lower sections, and includes an upper chuck 57 and a lower chuck 59. By tightening the upper chuck 57 and the lower chuck 59 using multiple fasteners 55A, the sample T is clamped by the fixture 41.

[0049] Figure 6 This is a three-dimensional view of test bench 9.

[0050] The test bench 9 has four support columns 61 extending upward from the base 3 and a base 63 that is roughly square in shape when viewed from above, supported on the upper end of the support columns 61.

[0051] Flat plates 65 are fixed to the four sides of the base 63 by bolts 65A. Recesses 65B are formed at two locations on the plates 65, and support members 69 are arranged in each recess 65B.

[0052] like Figure 5 As shown, the support member 69 is located vertically below the clamp 41, restricting the vertical downward movement of the clamp 41. Because the clamp 41 is located at the front end of the connecting rod 45A and is relatively heavy, it is prone to tipping vertically downward due to its own weight. However, by supporting it from below with the support member 69, its vertical downward movement can be restricted.

[0053] Figure 7 This is a perspective view of support member 69. Figure 8 This is a top view of support member 69. Figure 9 This is a side view of support member 69.

[0054] like Figure 7 , Figure 8 and Figure 9 As shown, the support member 69 includes a pair of side plates 169, an annular movable body 170 supported on the pair of side plates 169, and a plurality of needle-shaped members 171 that are rotatably supported on the surface of the movable body 170.

[0055] The movable body 170 is tracked. The needle-shaped member 171 is arranged such that its axis is orthogonal to the rotation direction of the movable body 170. The needle-shaped member 171... Figure 9 It can rotate freely in the direction of arrow A. The movable body 170° rotates along... Figure 9 The direction of arrow B can be rotated freely.

[0056] The needle-shaped component 171 is an example of a rotating component.

[0057] A protrusion 173 is mounted on a pair of side plates 169. A support member 69 is disposed in a recess 65B of a plate 65 and is fixed to the plate 65 by a fastener 175. The fastener 175 passes through a fixing hole 174 in the protrusion 173 and is fixed to the plate 65.

[0058] Support element 69 is a so-called linear roller bearing.

[0059] The aforementioned clamp 41 is placed on the upper surface of the support 69 and moves in the stretching direction. Multiple pin-shaped members 171 are exposed on the upper surface of the support 69, forming a generally horizontal surface. By rotating the movable part 170 of the support 69, and consequently the pin-shaped members 171, resistance is less likely to be applied to the clamp 41 when it moves in the stretching direction. The pin-shaped members 171 function as rollers to facilitate smooth movement in the stretching direction.

[0060] Support member 69 Figure 4 and Figure 5 As shown, when viewed from above, it is formed into a rectangular shape with width in the stretching direction of the clamp 41. For example... Figure 4 As shown, a pair of support members 69 are disposed on one side and the other side of the clamp 41 in a direction orthogonal to the stretching direction.

[0061] exist Figure 5 The image shows clamp 41 in the +X direction. (See image for reference.) Figure 5 As shown, more than half of the area of ​​the support member 69 abuts against the lower surface of the connecting portion 53 of the clamp 41, supporting the clamp 41 from below. For example, as the clamp 41 moves, the support member 69 also abuts against the rear end side of the clamp 41 and the front end side of the connecting rod 45A.

[0062] like Figure 6 As shown, plates 65 are respectively installed on the corresponding parts of the base 63, so the height can be adjusted by adjusting the tightness of the bolts 65A to correspond to the four clamps 41 respectively.

[0063] Furthermore, since a space S that extends vertically and horizontally is generated in the center of the base 63 where the sample T is placed, corresponding to the height of the support member 69 provided by the plate 65, it is possible to suppress the situation where the sample T interferes with the base 63.

[0064] Reference Figure 4 The specimen T is stretched in four directions by a pair of first clamps 41X that apply a test force along the X direction and a pair of second clamps 41Y that apply a test force along the Y direction orthogonal to the X direction. That is, the specimen T is stretched in the X-axis direction and the Y-axis direction orthogonal to the X-axis direction.

[0065] In this embodiment, the clamp 41 is prevented from moving vertically downward by the support member 69, but it is easy to move in the stretching direction. Furthermore, the clamp 41 is not restricted by the support member 69 from moving in the horizontal direction, which is different from the stretching direction. The rod 45 connected to the clamp 41 is restricted from moving in a direction different from the stretching direction by the rod support portion 49, etc., but it can move slightly in the horizontal direction.

[0066] Therefore, for example, when the specimen T deforms symmetrically in the +X and -X directions and the strain in the +Y direction is greater than that in the -Y direction, the clamp 41 does not counteract the load in the +Y direction. Furthermore, when the specimen T deforms symmetrically in the +Y and -Y directions and the strain in the +X direction is greater than that in the -X direction, the clamp 41 does not counteract the load in the +X direction.

[0067] In this embodiment, when the test force is applied symmetrically to the center of the specimen T by multiple clamps 41, the constraint of the clamps 41 as in the past is not caused. The resistance generated during the tensile test can be suppressed while preventing the clamps 41 from falling forward, thereby improving the reliability of the tensile test results of the specimen T.

[0068] [2. Other implementation methods]

[0069] The above-described embodiments are merely illustrative of one technical solution of the present invention, and can be arbitrarily modified and applied without departing from the spirit of the present invention.

[0070] In the above embodiments, a biaxial tensile testing machine 1 is exemplified as a material testing machine for tensile testing specimen T in two axes, but it is not limited to this. In other embodiments, the material testing machine has three or more clamps 41 arranged substantially horizontally, with at least two clamps 41 arranged in a manner where their axes are not parallel. In this case, although the specimen T may deform asymmetrically in a direction different from one axis, since the plate 65, exemplified as a support member, supports the clamps 41 so that they can move in directions other than that axis, it achieves the same function and effect as the embodiments described above.

[0071] For example, a material testing machine can be a structure with three clamps 41 arranged at 120-degree angles, or it can be a structure with two parallel clamps 41 and one clamp 41 in another direction, for a total of three clamps 41. In addition, a material testing machine can also be a multi-axis material testing machine with more than three clamps 41.

[0072] In the above embodiments, a tensioning mechanism 5 constituting a ball screw is exemplified as the mechanism for axially tensioning the clamp 41, but it is not limited to this. In other embodiments, the clamp 41 may also be a structure that is tensioned by a tensioning device such as an actuator.

[0073] In the above embodiments, the support member 69 is exemplified as a linear roller bearing structure, but it is not limited to this as long as it does not cause horizontal constraint on the clamp 41. In other embodiments, the support member 69 may also be a sliding member that reduces frictional resistance. The reduction of frictional resistance is achieved by the surface shape of the sliding member, the application of lubricant, etc. Furthermore, the support member 69 may not have a needle-shaped member 171, but may have a structure that is configured as a rotatable ball. A ball is an example of a rotating member. The support member 69 is not limited to a bearing as long as the part that abuts against the clamp 41 can rotate in coordination with the movement of the clamp 41.

[0074] In the above embodiment, the structure is designed such that the plate 65 is not arranged in the space S of the base 63 below the specimen T held by the clamp 41. In the space S in the center of the base 63, a predetermined component may be arranged in any area that does not interfere with the specimen T during the testing process of the material testing machine.

[0075] [3. Technical Solution]

[0076] Those skilled in the art will understand that the above-described exemplary embodiments are specific examples of the following technical solutions.

[0077] (Item 1)

[0078] One technical solution involves a material testing machine that uses three or more clamps arranged in a generally horizontal position to grip a specimen and apply a test force symmetrically to the center of the specimen. A support is provided below the clamps, which allows the clamps to move in a generally horizontal direction and restricts the clamps from moving in a generally vertical direction.

[0079] According to the material testing machine described in item 1, the support member supports the clamp from below, but does not restrict movement in any other direction. Therefore, it is possible to prevent the clamp of the material testing machine from tipping forward and to avoid generating resistance during tensile testing.

[0080] (Item 2)

[0081] According to the material testing machine of claim 1, the support member has a pair of side plates, an annular movable body supported on the side plates, and a plurality of rotating members supported on the surface of the movable body in a rotatable manner, thereby allowing the fixture to move in a generally horizontal direction by rotating the movable body and rotating the rotating members.

[0082] According to the material testing machine described in item 2, the support does not hinder the axial movement of the fixture as it normally would. Therefore, it is possible to stretch the specimen without applying unnecessary resistance during the stretching process of the fixture.

[0083] (Item 3)

[0084] According to the material testing machine of claim 2, the rotating member is a needle-shaped member, which is configured such that the axis of the needle-shaped member is orthogonal to the rotation direction of the movable body.

[0085] According to the material testing machine described in item 3, the needle-shaped part rotates as the fixture moves, and does not become a resistance to the axial movement that the fixture normally performs. Therefore, it is possible to stretch the specimen without applying unnecessary resistance during the stretching process of the fixture.

[0086] (Item 4)

[0087] The material testing machine according to any one of claims 1 to 3, wherein the fixture includes a pair of first fixtures that apply a test force in the X direction and a pair of second fixtures that apply a test force in the Y direction orthogonal to the X direction.

[0088] According to the material testing machine described in item 4, a specimen can be stretched in another direction orthogonal to one direction. Therefore, it is possible to perform biaxial tensile tests using specimens in the shape of an X or a cross using the material testing machine.

Claims

1. A material testing machine that uses three or more clamps arranged approximately horizontally to grip a specimen and apply a test force symmetrically to the center of the specimen, wherein, A support is provided below the clamp, which allows the clamp to move in a generally horizontal direction and restricts the clamp to move in a generally vertical direction.

2. The material testing machine according to claim 1, wherein, The support member includes a pair of side plates, an annular movable body supported on the side plates, and a plurality of rotating members rotatably supported on the surface of the movable body. By rotating the movable body and the rotating member, the clamp is allowed to move in a generally horizontal direction.

3. The material testing machine according to claim 2, wherein, The rotating member is a needle-shaped component, which is configured such that its axis is orthogonal to the rotation direction of the movable body.

4. The material testing machine according to any one of claims 1 to 3, wherein, The fixture includes a pair of first fixtures that apply a test force in the X direction and a pair of second fixtures that apply a test force in the Y direction orthogonal to the X direction.

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