JP2013160674A - Material testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material testing machine capable of appropriately performing a material test with respect to a thin plate-like test piece even when a general material testing machine is used.SOLUTION: A test piece holding mechanism 20 includes: first and second front surface side abutment members; first and second rear surface side abutment members; a first connection member 35; a second connection member 36; and an energization unit 37 for energizing the first and second front surface side abutment members and the first and second rear surface abutment members in a mutually contiguous direction. The first and second front surface abutment members are constituted by grip tooth parts for gripping the end of a test piece and pressure parts for pressurizing the center of the test piece. The first and second rear surface abutment members are constituted by grip tooth parts for gripping the end of the test piece and pressure parts for pressurizing the center of the test piece.

Description

  The present invention relates to a material testing machine that performs a tensile test or a compression test on a thin plate-shaped test piece.

  For example, when a material test is performed on a test piece such as a stainless steel sheet for electronic parts with a continuous reversal load of tension and compression, a material testing machine is required to prevent buckling of the test piece. It becomes. As such a material testing machine, for example, a material testing machine provided with a comb-shaped test piece pressing member described in Non-Patent Document 1 has been proposed.

  12 is a schematic side view of a conventional material testing machine described in Non-Patent Document 1, and FIG. 13 is a perspective view showing lower molds 101 and 102, upper molds 103 and 104, and the like.

  The lower molds 101 and 102 and the upper molds 103 and 104 are comb-shaped molds each having a comb-tooth shape with their tips engaged with each other. Of these lower molds 101, 102 and upper molds 103, 104, the lower mold 101 is fixed to the die set lower plate 108. Further, the lower die 102 is fixed to a slide guide moving base 109 and is movable in the left-right direction in FIG. When the material test is performed, the test piece 100 is placed on a pair of lower molds 101 and 102 having comb teeth portions engaged with each other, and both ends thereof are fixed to the lower molds 101 and 102.

  Next, a strain gauge 106 is attached to the test piece 100. The lead wire of the strain gauge 106 is guided to the outside through a through hole 107 formed in the upper mold 103. Then, on the basis of the four positioning pins 105 (see FIG. 13), a pair of upper molds 103 and 104 having their comb teeth engaged with each other are placed on the test piece 100, and further A roller 114 is placed on top of the molds 103 and 104. Then, the die set upper plate 110 is lowered by the hydraulic cylinder 111 and a restraining force for preventing buckling is applied to the test piece 100.

  In this state, the lower die 102 is driven left and right together with the upper die 104 by the hydraulic cylinder 113, and the test force at that time is measured by the load cell 112. By adopting such a configuration, it is possible to execute a material test by applying a continuous inversion load of tension and compression to the surface of the test piece 100 without buckling the test piece 100.

"Iron and Steel" Vol. 95 (2009) No. 11 “Asymmetry of tensile / compressive stress of SUS304 stainless steel sheet for electronic parts and its effect on bending and springback behavior”

  Although the above-described conventional material testing machine can suitably execute a material test without buckling the test piece 100, the lower molds 101 and 102 and the upper molds 103 and 104 are arranged in the horizontal direction. Since the lower molds 101 and 102 and the upper molds 103 and 104 are moved in the horizontal direction by the hydraulic cylinder 113, it is necessary to adopt a dedicated configuration different from a general material testing machine. There is. Moreover, since the load direction with respect to the test piece 100 is limited to the horizontal direction and the load direction of the test force and the direction of gravity do not match, there is a possibility that the accuracy of the material test may be affected.

  The present invention has been made to solve the above-described problem, and even when the load direction of the test force and the direction of gravity are matched, a material test can be performed with high accuracy on a thin plate-shaped test piece. It is a first object of the present invention to provide a material testing machine capable of suitably performing a material test on a thin plate test piece even when a general material testing machine is used.

  From another point of view, the above-described conventional material testing machine has a problem that it takes time to attach the strain gauge 106 to the test piece. Further, the lead wire of the strain gauge 106 is inserted into the through hole. There is also a problem that it takes a long time to work around the lead wire to pass the wire and guide it to the outside.

  The present invention has been made to solve the above-described problems, and by enabling the use of a displacement meter, a material test that can easily and accurately execute a material test without using a strain gauge. The second object is to provide a machine.

  The invention according to claim 1 is a material testing machine that performs a tensile test or a compression test on a thin plate-shaped test piece, and includes a gripping tooth portion that grips an end of the surface of the test piece, A pressing portion that presses the center of the front surface, each having a comb-tooth shape in which the tips of the pressing portions engage with each other; and an end of the back surface of the test piece First and second back-side abutting members each having a gripping tooth portion and a pressing portion that presses the center of the back surface of the test piece, each having a comb-tooth shape in which the tips of the pressing portions engage with each other; The first and second front surface side contact members and the first and second back surface side contact members are urged toward each other in a state where the first and second rear surface side contact members are in contact with each other through the test piece. Biasing means, the first front surface side contact member, the first back surface side contact member and the crosshead A first connecting member that connects the second back side contact member, a second connecting member that connects the second back side contact member and the table, and a displacement meter that measures the displacement of the test piece And the second connecting member has the first and second surface-side contact members and the first and second back-side contact members oriented in the vertical direction about an axis oriented in the horizontal direction. The test posture and the first and second front-side contact members and the first and second back-side contact members can swing between a preparation posture in which the first and second back-side contact members are oriented horizontally along the surface of the table. It is characterized by being.

  According to a second aspect of the present invention, in the first aspect of the invention, the displacement meter measures a displacement of a test piece by a change in a distance between two arms. In the pressing portion of the back surface side contact member, through-holes are formed in the direction intersecting the surface of the test piece, and the tips of the two arms of the displacement meter are the first and second The test piece is brought into contact with each other through through holes formed in the back surface side contact member.

  According to a third aspect of the present invention, in the second aspect of the invention, the first and second front surface side contact members and the first and second rear surface side contact members are each of a test piece. A gripping tooth part for gripping the end part and a pressing part having a tip having a comb tooth shape for pressing the center part of the test piece are formed, and the through hole is formed by the first and second rear surface side contacts. The first connecting member is formed at a pressing portion of the contact member, and connects the gripping tooth portion and the cross head of the first front surface side contact member and the first back surface side contact member, The second connecting member connects the gripping tooth portion and the table in the second back surface side contact member and the second back surface side contact member.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the first and second surface sides are arranged in a state where the second connecting member is arranged in the preparation posture. A guide member that guides the contact member and the first and second back surface contact members is attached to the table.

  According to the first aspect of the present invention, the first and second front-side contact members and the first and second back-side contact members are in the state of preparations facing in the horizontal direction and are thin plate-like test pieces. After setting, the material test can be executed with the first and second front-side contact members and the first and second back-side contact members as test postures facing in the vertical direction. For this reason, it is possible to easily execute a material test while preventing buckling of a thin plate-shaped test piece. Further, by making the load direction of the test force coincide with the direction of gravity, the material test can be executed with higher accuracy.

  According to the second aspect of the present invention, it is possible to execute a material test using a displacement meter while preventing buckling of a thin plate-shaped test piece. For this reason, it is possible to easily perform a material test by omitting troublesome work as in the case of using a strain gauge.

  According to the third aspect of the present invention, the first and second surface abutting members and the first and second back surface abutting members prevent the buckling of the test piece by the pressing members. The test force can be applied to the test piece by the action of the gripping tooth portions of the two front surface contact members and the first and second back surface contact members.

  According to invention of Claim 4, when fixing the 1st, 2nd surface side contact member and the 1st, 2nd back surface side contact member to the 1st connection member or the 2nd connection member, It becomes possible to fix the 1st, 2nd surface side contact member and the 1st, 2nd back surface side contact member with respect to a table.

1 is a schematic diagram of a material testing machine according to the present invention. 2 is a perspective view showing a test piece holding mechanism 20 together with a displacement meter 25. FIG. 3 is a longitudinal sectional view showing a test piece holding mechanism 20 together with a displacement meter 25. FIG. 4 is a perspective view showing the first front surface side contact member 31 and the first back surface side contact member 33 together with the first connecting member 35. FIG. FIG. 4 is a perspective view showing a state where an urging unit 37 is removed from a test piece holding mechanism 20. FIG. 4 is a perspective view showing a state where an urging unit 37 is removed from a test piece holding mechanism 20. FIG. 4 is a perspective view showing a state where an urging unit 37 is removed from a test piece holding mechanism 20. FIG. 4 is a longitudinal sectional view showing a state where an urging unit 37 is removed from a test piece holding mechanism 20. 2 is a perspective view showing first and second front surface side contact members 31 and 32 and first and second back surface side contact members 33 and 34 together with a test piece S. FIG. It is a sectional side view for showing the shape of comb-tooth shaped parts 64, 65, 66, and 67 in press part 31b, 32b, 33b, and 34b. 4 is a perspective view of an urging unit 37. FIG. It is a side surface schematic diagram of the conventional material testing machine. It is a perspective view which shows the lower metal mold | dies 101 and 102, the upper metal mold | die 103,104, etc. in the conventional material testing machine.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a material testing machine according to the present invention.

  This material testing machine includes a base 11 having a table 14, a pair of left and right screw rods 12 erected on the base 11, a yoke 13 disposed above these screw rods 12, A nut portion 18 that is screwed into the pair of left and right screw rods 12 is provided, and a cross head 15 that is raised and lowered with respect to the screw rod 12 is provided. The cross head 15 is provided with an upper connecting portion 16, and the table 14 is provided with a lower connecting portion 17. And between these upper connection part 16 and lower connection part 17, the test piece holding mechanism 20 which is the characteristic part of this invention for hold | maintaining the thin-plate shaped test piece mentioned later is arrange | positioned.

  Synchronous pulleys 19 that engage with the synchronous belt 21 are disposed at the lower ends of the pair of screw rods 12, respectively. The synchronous belt 21 is also engaged with a synchronous pulley 22 that is rotated by driving of a motor 23. For this reason, the pair of screw rods 12 rotate in synchronization with the drive of the motor 23. Then, as the pair of screw rods 12 rotate in synchronization, the cross head 15 moves up and down in the axial direction of the pair of screw rods 12.

  A load cell 24 is disposed between the crosshead 15 and the first coupling mechanism 16, and a test force applied to the thin plate-shaped test piece is detected by the load cell 24. Further, the amount of displacement between the upper and lower gauge points of the test piece is detected by a displacement meter 25 that measures the displacement of the test piece based on a change in the distance between the two arms 27. Signals from the load cell 24 and the displacement meter 25 are input to the control circuit 26. Then, the control circuit 26 creates a drive control signal for the motor 23 based on the signals from the load cell 24 and the displacement meter 25. Thereby, rotation of the motor 23 is controlled and a tensile test or a compression test is performed.

  Next, the configuration of the test piece holding mechanism 20 for holding a thin plate-like test piece will be described. 2 is a perspective view showing the test piece holding mechanism 20 together with the displacement meter 25, and FIG. 3 is a longitudinal sectional view of FIG. FIG. 4 is a perspective view showing the first front surface side contact member 31 and the first back surface side contact member 33 together with the first connecting member 35. 5, 6, and 7 are perspective views illustrating a state in which the urging unit 37 is removed from the test piece holding mechanism 20. Here, FIG. 5 shows a state in which the first and second front surface side contact members 31 and 32 and the first and second back surface side contact members 33 and 34 are in a test posture in the vertical direction. 6 and 7, the first and second front surface side contact members 31 and 32 and the first and second rear surface side contact members 33 and 34 face the horizontal direction along the surface of the table 14. It shows a state of preparation posture. FIG. 6 shows a state in which the first and second front surface side contact members 31 and 32 and the first and second rear surface side contact members 33 and 34 are set, and FIG. 1 and 2 show that the second surface side contact members 31 and 32 are not set. Further, FIG. 8 is a longitudinal sectional view of FIG.

  The test piece holding mechanism 20 includes first and second front surface side contact members 31, 32, first and second back surface side contact members 33, 34, a first connection member 35, and a second connection. A member 36; and a biasing unit 37 that biases the first and second front surface side contact members 31, 32 and the first and second rear surface side contact members 33, 34 in a direction approaching each other. .

  The first connecting member 35 is for connecting the first front surface side contact member 31 and the first back surface side contact member 33 and the upper connection portion 16 in the cross head 15. As shown in FIGS. 3 and 4, the first connecting member 35 has a hole 41 for inserting the pin 44 shown in FIG. 2 and a lock nut 42. When the first connecting member 35 is connected to the upper connecting portion 16 shown in FIG. 1, the pin 44 is inserted into the hole 41 and the lock nut 42 is rotated so that the pin 44 is pressed by the lock nut 42. Then, the first connecting member 35 and the upper connecting portion 16 are fixed. Further, as shown in FIG. 4, the first connecting member 31 is provided with a hole 43 for allowing the arm 27 in the displacement meter 25 to pass therethrough.

  The second connection member 36 is for connecting the second front surface side contact member 32 and the second back surface side contact member 34 and the lower connection portion 17 of the table 14. As shown in FIG. 3, a hole 45 for inserting the pin 46 shown in FIGS. 2 and 5 is formed in the second connecting member 36, and a lock nut 47 is provided. When the second connecting member 36 is connected to the lower connecting portion 17, the pin 46 is inserted into the hole 45 and the lock nut 47 is rotated to press the lower connecting portion 17 by the lock nut 47. The second connecting member 36 and the lower connecting portion 17 are fixed.

  When the lock nut 47 is loosened and the second connecting member 36 and the lower connecting portion 17 are not fixed, the second connecting member 36 can swing around the pin 46. Therefore, by swinging the second connecting member 36, the first and second front surface side contact members 31, 32 and the first and second back surface side contact members 33, 34 are moved to FIG. As shown, the first and second front surface side contact members 31 and 32 and the first and second rear surface side contact members 33 and 34 together with the first and second connection members 35 and 36 face the vertical direction. As shown in FIG. 6, the first and second front-side contact members 31 and 32 and the first and second back-side contact members 33 and 34 are the first and second connection members 35. , 36 and the preparatory posture that faces the horizontal direction along the surface of the table 14 can be swung.

  Between the first connecting member 35 and the second connecting member 36, four roller members 51 for allowing the first connecting member 35 to slide with respect to the second connecting member 36 are disposed. Further, the second connecting member 36 is provided with a pair of holes 52 for allowing the two arms 27 of the displacement meter 25 to pass therethrough. Further, the second connecting member 36 is provided with a stopper 48 for preventing the urging unit 37 described later from dropping.

  FIG. 9 is a perspective view showing the first and second front surface side contact members 31 and 32 and the first and second rear surface side contact members 33 and 34 together with the test piece S. FIG.

  The first surface abutting member 31 has a gripping tooth portion 31a for gripping the end portion of the thin plate-shaped test piece S and a pressing portion having a comb-like portion 64 at the tip for pressing the center portion of the test piece S. The second surface abutting member 32 includes a gripping tooth portion 32a for gripping the end portion of the test piece S and a comb tooth-like portion at the tip for pressing the central portion of the test piece S. And a pressing portion 32b having 65. Similarly, the first back surface abutting member 33 has a gripping tooth portion 33a for gripping the end portion of the test piece S, and a pressing portion having a comb-like portion 66 at the tip end for pressing the center portion of the test piece S. The second back contact member 34 is composed of a portion 33b, and the second back contact member 34 has a gripping tooth portion 34a for gripping the end portion of the test piece S and a comb tooth-like portion at the tip end for pressing the central portion of the test piece S. And a pressing portion 34 b having 67.

  The surface 61 on the side of the test piece S in the gripping tooth portions 31a, 32a, 33a, and 34a is a gripping tooth region by forming an uneven portion. A pair of holes 63 are formed in each gripping tooth portion 31a, 32a, 33a, 34a. The gripping tooth portions 31a and 33a are fixed to the first connecting member 35 by a screw 53 that passes through the hole 63 shown in FIG. Further, the gripping tooth portions 32a and 34a are fixed to the second connecting member 36 by a screw 54 penetrating the hole 63 shown in FIG. Furthermore, a hole 62 for allowing the arm 27 of the displacement meter 25 to pass therethrough is formed in the pressing portions 33b, 34b of the first and second back contact members 33, 34, respectively.

  FIG. 10 is a side sectional view for illustrating the shapes of the comb-like portions 64, 65, 66, and 67 in the pressing portions 31b, 32b, 33b, and 34b.

  As shown in this figure, the surfaces of the pressing portions 31b, 32b, 33b, and 34b that are in contact with the test pieces S at the tips of the comb-like portions 64, 65, 66, and 67 are rounded. Chamfering is done. This prevents a phenomenon in which the tips of the comb-like portions 64, 65, 66, and 67 in the pressing portions 31b, 32b, 33b, and 34b get into the surface of the test piece S during the material test to be described later. The relative movement of 31b, 32b, 33b, 34b and the test piece S can be easily performed.

  FIG. 11 is a perspective view of the urging unit 37 described above.

  As described above, the urging unit 37 urges the first and second front surface side contact members 31 and 32 and the first and second rear surface side contact members 33 and 34 in the direction of approaching each other. Is to do. The urging unit 37 has a structure in which a pair of support plates 71 and 72 are connected by four connecting members 73. An air cylinder 74 is disposed on one support plate 72, and a frame 75 having four roller members 76 is disposed on the cylinder rod of the air cylinder 74. The other support plate 71 is provided with a pair of holes 77 for allowing the arm 27 of the displacement meter 25 to pass therethrough. In addition, in FIG. 11, illustration of a pair of fixing member 29 for fixing the displacement meter 25 shown in FIG. 3 is abbreviate | omitted.

  As shown in FIGS. 2 and 3, the support plate 71 in the urging unit 37 contacts the second connecting member 36. Further, the four roller members 76 in the urging unit 37 abut on the first and second surface side abutting members 31 and 32. In this state, the air cylinder 74 presses the first and second surface-side contact members 31 and 32 through the frame 75 and the roller member 76. For this reason, the first and second back-side contact members 33 and 34 are pressed through the support plate 71, the second connecting member 36, the roller member 51, and the first connecting member 35 by the urging force of the air cylinder 74. Then, the first and second surface-side contact members 31 and 32 are pressed through the frame 75 and the roller member 76. Thus, the first and second front surface side contact members 31 and 32 and the first and second back surface side contact members 33 and 34 are close to each other in a state of contacting each other via the test piece S. Will be biased in the direction.

  2, 5, 6, and 7, the table 14 is provided with a guide member 38 for guiding the test piece holding mechanism 20. The guide member 38 includes the first and second front surface side contact members 31 and 32 and the first and second back surface side contact members 33 and 34 together with the first and second connection members 35 and 36. The first and second surface-side contact members 31 and 32 and the first and second surface-side contact members 31 and 32 are provided via the first and second connecting members 35 and 36 in a state of being in a preparation posture that faces the horizontal direction along the surface. It has the structure which guides the back surface side contact members 33 and 34 of 2 back. The guide member 38 is formed with a recess 39 for receiving a stopper 48 for preventing the urging unit 37 from dropping.

  When the material test is performed in the material testing machine having the above-described configuration, as shown in FIG. 7, the second connecting member 36 is swung around the shaft 46, and the second connecting member 36 is moved to the table 14. The preparatory posture is directed horizontally along the surface. In this state, as shown in FIG. 7, the first and second back surface side contact members 33 and 34 are set on the second connecting member 36, and the first and second back surface side contact members 33 are set. , 34 is placed on the test piece S. Thereafter, as shown in FIG. 6, the first and second surface-side contact members 31 and 32 are placed on the test piece S.

  Thereafter, the gripping tooth portions 31 a and 33 a of the first front surface side contact member 31 and the first back surface contact member 33 are fixed to the first connection member 35 by the screw 53 described above. Further, the gripping tooth portions 32 a and 34 a of the second front surface side contact member 32 and the second back surface contact member 34 are fixed to the second connecting member 36 by the screws 54. During this screwing operation, the first and second front surface side contact members 31 and 32 and the first and second back surface side contact members 33 and 34 are connected via the first and second connection members 35 and 36, respectively. Guided by the guide member 38. For this reason, even when the rigidity of the first and second connecting members 35 and 36 is low, the first and second front surface side contact members 31 and 32 and the first and second back surface side contact members 33 and 34 are used. It is possible to execute the screwing operation without affecting the above.

  Next, the second connecting member 36 is swung around the shaft 46, and as shown in FIG. 5, the first and second front surface side contact members 31, 32 and the first and second rear surface side contact members are contacted. The test posture is such that the members 33 and 34 face the vertical direction. Then, as shown in FIG. 2, the urging unit 37 is mounted on the outer periphery of the test piece holding mechanism 20.

  Further, the pair of arms 27 in the displacement meter 25 are inserted into holes 77 (see FIG. 11) formed in the support plate 71 in the urging unit 37. The pair of arms 27 includes a hole 77 of the support plate 71, a hole 43 formed in the first connecting member 35 (see FIG. 4), and a hole 52 formed in the second connecting member 36 (see FIG. 5). And the first and second front surface side contact members 31, passing through the holes 62 (see FIG. 9) formed in the pressing portions 33b and 34b of the first and second back surface side contact members 33 and 34. 32 and the test piece S held between the first and second back-side contact members 33 and 34. Note that the distal ends of the pair of arms 27 in the displacement meter 25 are needle-shaped, and the distal ends of the pair of arms 27 pierce the surface of the test piece S.

  Then, the air cylinder 74 in the urging unit 37 is driven. At this time, the support plate 71 in the urging unit 37 contacts the second connecting member 36. Further, the four roller members 76 in the urging unit 37 abut on the first and second surface side abutting members 31 and 32. In this state, the air cylinder 74 presses the first and second surface-side contact members 31 and 32 through the frame 75 and the roller member 76. As a result, the first and second back-side contact members 33 and 34 are pressed via the support plate 71, the second connecting member 36, the roller member 51, and the first connecting member 35, and the first and second The front-side contact members 31 and 32 are pressed via the frame 75 and the roller member 76. Thereby, the 1st, 2nd surface side contact members 31 and 32 and the 1st, 2nd back surface side contact members 33 and 34 press the test piece S from the both surfaces.

  In this state, the cross head 15 is moved up and down by driving the motor 23 shown in FIG. At this time, the upper end portion of the test piece S is gripped by the grip tooth portion 31a of the first front surface contact member 31 and the grip tooth portion 33a of the first back surface contact member 33, and the lower end portion of the test piece S is The gripping tooth portion 32a of the second front surface contact member 32 and the gripping tooth portion 34a of the second back surface contact member 34 are gripped. The gripping tooth portion 31 a of the first front surface contact member 31 and the gripping tooth portion 33 a of the first back surface contact member 33 are connected to the upper connection portion 16 attached to the cross head 15. 35, the grip tooth portion 32a of the second front surface contact member 32 and the grip tooth portion 34a of the second back surface contact member 34 are connected to the lower connection portion 17 attached to the table 14. It is fixed to the second connecting member 36. Further, due to the action of the roller members 51, 76, the first connecting portion 35, together with the first and second front surface side contact members 31, 32 and the first and second back surface side contact members 33, 34, 2 It can move with respect to the connecting member 36. For this reason, when the cross head 15 moves up and down, the material test can be executed by applying a continuous reversal load of tension and compression to the test piece S.

  At this time, the central portion of the test piece S is driven by the air cylinder 74 so that the pressing portions 31b and 32b and the first and second back surface contact members of the first and second surface contact members 31 and 32 are driven. It is clamped by pressing portions 33b and 34b in 33 and 34. Even if the distance between the pressing portions 31b and 32b and the pressing portions 33b and 34b changes, it is possible to cope with this change in distance by the action of the comb-like portions 64, 65, 66, and 67. Become. For this reason, even when a tension / compression continuous reversal load is applied to the thin test piece S, it is possible to easily prevent the test piece S from buckling.

  The displacement amount between the upper and lower gauge points of the test piece S when the continuous inversion load is applied to the thin plate-like test piece S in this way is the change in the distance between the two arms 27 in the displacement meter 25. Detected as

  As described above, according to the material testing machine described above, since the test piece holding mechanism 20 can take the preparation posture and the test posture, the material test is performed in the test posture state after setting the test piece S in the preparation posture state. Thus, it is possible to easily execute a material test on the thin plate-shaped test piece S using a normal vertical material testing machine.

  In the above-described embodiment, the first and second surface contact members 31 and 32 are constituted by the gripping tooth portions 31a and 32a and the pressing portions 31b and 32b, and the first and second back surface contact members. 33 and 34 are constituted by gripping tooth portions 33a and 34a and pressing portions 33b and 34b. However, the gripping tooth portions 31a, 32a, 33a, 34a and the pressing portions 31b, 32b, 33b, 34b may be integrated.

  In the above-described embodiment, the displacement amount between the upper and lower test marks of the test piece S is detected by the displacement meter 25 that measures the displacement of the test piece by the change in the distance between the two arms 27. As a displacement meter for measuring the amount of displacement of the test piece S, a strain gauge 106 as shown in FIG. 13 can be used.

DESCRIPTION OF SYMBOLS 11 Base 12 Screw rod 13 Yoke 14 Table 15 Cross head 16 Upper connection part 17 Lower connection part 20 Test piece holding mechanism 23 Motor 24 Load cell 25 Displacement meter 26 Control circuit 27 Arm 31 1st surface side contact member 31a Grasp tooth Portion 31b Pressing portion 32 First back surface side abutting member 32a Grasp portion 32b Pressing portion 33 Second surface side abutting member 33a Grasp portion 33b Pressing portion 34 Second back side abutting member 34a Grasp portion 34b Pressing portion 35 First connecting member 36 Second connecting member 37 Energizing unit 38 Guide member 46 Pin 51 Roller member 62 Hole portion 64 Comb tooth portion 65 Comb tooth portion 66 Comb tooth portion 67 Comb tooth portion 74 Air cylinder 76 Roller member S Test piece

Claims (4)

A material testing machine for performing a tensile test or a compression test on a thin plate-shaped test piece,
A first tooth having a comb tooth shape that includes a gripping tooth portion that grips an end portion of the surface of the test piece, and a pressing portion that presses a center portion of the surface of the test piece, and the tips of the pressing portions engage with each other; A second surface-side contact member;
A first tooth having a comb tooth shape that includes a gripping tooth portion that grips an end portion of the back surface of the test piece and a pressing portion that presses a central portion of the back surface of the test piece, and the tips of the pressing portions engage with each other; A second back side contact member;
The first and second front surface side contact members and the first and second back surface side contact members are urged in a direction approaching each other in a state of contacting with each other through the test piece. Means,
A first connecting member that connects the first front surface side contact member and the first back surface side contact member and the crosshead;
A second connecting member that connects the second back surface side contact member and the second back surface side contact member and the table;
A displacement meter for measuring the displacement of the test piece,
The second connecting member has a test posture in which the first and second surface-side contact members and the first and second back-side contact members are oriented in the vertical direction around an axis that faces the horizontal direction, The first and second front surface side contact members and the first and second back surface side contact members can swing between a preparation posture that faces the horizontal direction along the surface of the table. Features material testing machine. The material testing machine according to claim 1,
The displacement meter measures the displacement of the test piece by the change in the distance between the two arms,
Through holes are formed in the pressing portions of the first and second back-side contact members in the direction intersecting the surface of the test piece,
The material testing machine in which the tips of the two arms of the displacement meter are in contact with the test piece through through holes respectively formed in the first and second back surface side contact members. The material testing machine according to claim 2,
The first and second front surface side abutting members and the first and second back surface side abutting members respectively press the gripping tooth portion for gripping the end of the test piece and the central portion of the test piece. The tip for making is composed of a pressing portion having a comb-teeth shape,
The through hole is formed in the pressing portion of the first and second back surface side contact members,
The first connecting member connects the gripping tooth portion and the cross head in the first front surface side contact member and the first back surface side contact member,
The second connecting member is a material testing machine for connecting a grip tooth portion and a table in the second back surface side contact member and the second back surface side contact member. In the material testing machine according to any one of claims 1 to 3,
A guide member that guides the first and second front surface side contact members and the first and second rear surface side contact members in a state where the second connecting member is disposed in the preparation posture. A material testing machine attached to the machine.

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