JP6418106B2 - Material testing machine - Google Patents

Description

  The present invention relates to a material testing machine that performs a material test by applying a test force to a test piece under reduced pressure such as a vacuum state.

  FIG. 6 is a schematic diagram of such a conventional material testing machine.

  In this material testing machine, a pair of frames 12 are erected on a base 11, and the upper ends of these frames 12 are connected by a yoke 13. A pair of screw rods that rotate in synchronization with a drive mechanism (not shown) is disposed in the frame 12. Nuts provided at both ends of the cross head 14 are screwed to these screw rods, and the cross head 14 is moved up and down by the pair of screw rods rotating synchronously.

  A decompression chamber 21 is disposed on the base 11. The decompression chamber 21 is connected to a decompression mechanism 20 such as a vacuum pump. A platen 25 is disposed on the bottom surface of the decompression chamber 21. An opening 28 is formed in the upper wall of the decompression chamber 21. The rod 23 enters the decompression chamber 21 through the opening 28. A platen 24 is attached to the lower end of the rod 23. The test piece to be subjected to the compression test is pressed by the platen 24 and the platen 25 disposed on the bottom surface of the decompression chamber 21.

  The upper end of the rod 23 is fixed to a disc-shaped moving plate 18. The moving plate 18 is connected to a pair of suspension members 17 and a support member 16 that supports these suspension members 17. The support member 16 is connected to the crosshead 14 via the load cell 15.

  A pair of support bars 19 are erected on the upper surface of the decompression chamber 21, and a support plate 22 is disposed above the support bars 19. A substantially cylindrical bellows 26 is disposed between the lower surface of the support plate 22 and the upper surface of the moving plate 18. A substantially cylindrical bellows 27 is disposed between the lower surface of the moving plate 18 and the upper surface of the decompression chamber 21 so as to surround the rod 23. The bellows 26 disposed above the moving plate 18 and the bellows 27 disposed below the moving plate 18 have the same natural length and the same spring coefficient.

  The moving plate 18 is formed with a hole that communicates the internal space of the bellows 26 and the internal space of the bellows 27. In addition, the inner diameter of the opening 28 formed in the decompression chamber 21 is larger than the outer diameter of the rod 23, and the interior of the decompression chamber 21 and the inner space of the bellows 27 communicate with each other at the outer periphery of the rod 23. Yes. Therefore, the support plate 22 and the pair of bellows 26 and 27 form a space communicating with the decompression chamber 21 on the outer periphery of the rod 23.

  When a material test is performed by applying a test force to a test piece under reduced pressure using a material testing machine having such a configuration, the inside of the reduced pressure chamber 21 is decompressed by the decompression mechanism 20. Then, by lowering the cross head 14, the platen 24 is lowered via the suspension member 17, the moving plate 18 and the rod 23, and a test force is applied to the test piece disposed between the platens 24 and 25. At this time, regardless of the movement of the moving plate 18, the volume of the sealed space in the outer peripheral portion of the rod 23 formed by the support plate 22, the pair of bellows 26 and 27, and the decompression chamber 21 is always constant. For this reason, even if the amount of the rod 23 entering the inside of the decompression chamber 21 increases, the pressure in the decompression chamber 21 can be kept constant.

  When performing a material test by applying a test force to a test piece under reduced pressure using a material testing machine having such a configuration, the bellows 26 and 27 are deformed as the platen 24 is lowered. For this reason, the load due to the spring coefficient of these bellows 26 and 27 causes an error with respect to the measured value of the test force.

  In Patent Document 1, in a creep test apparatus that performs a test while heating a test piece in an atmosphere such as a vacuum or an inert gas, it occurs due to expansion and contraction of the bellows when the horizontal lever is maintained in a horizontal posture. There is disclosed a creep test apparatus in which a correction spring for correcting a load error is provided, one end of the correction spring is connected to a horizontal lever, and the other end of the correction spring is connected to a test tank.

  Further, in Patent Document 2, when a material test is performed on a test piece in a pressure vessel connected to an expansion / contraction bellows, an elastic load accompanying expansion / contraction of the expansion / contraction bellows is detected from a detection signal indicating a load load from a load cell. A load detecting device for a material testing machine is disclosed in which a correction signal is subtracted to obtain a load signal.

JP-A-2-226040 Japanese Utility Model Publication No. 1-93546

  The creep test apparatus described in Patent Document 1 does not perform a general material test such as a compression test or a tensile test. In addition, the load detection device for a material testing machine described in Patent Document 2 requires complicated electrical adjustment and maintenance, and requires a relatively large cost to configure a feedback circuit.

  The present invention has been made in order to solve the above-described problems. With a simple mechanical configuration, an accurate material test can be executed by canceling the force applied to the test force by the deformation of the bellows. An object is to provide a material testing machine.

  The invention according to claim 1 is a material testing machine that performs a material test by applying a test force to a test piece under reduced pressure, and is arranged in the reduced pressure chamber by entering the reduced pressure chamber and the reduced pressure chamber. A rod for applying a test force to the test piece formed, a bellows which is disposed so as to surround the rod, and which forms a space communicating with the decompression chamber on an outer periphery of the rod, the rod and the rod A moving member connected to a bellows and movable with the rod, a moving mechanism for applying a test force to the test piece by moving the moving member, an elastic member coupled to the moving member, and the moving member By moving the moving member, the elastic member is deformed in the same direction as the moving member. A force balancing with the force applied to the moving member, characterized in that and an elastic member deformable mechanism to be applied to the moving member from the elastic member.

  According to a second aspect of the present invention, in the material testing machine according to the first aspect, the elastic member deformation mechanism includes a pulley that moves together with the moving member, one end connected to the apparatus main body, and the other end the elastic member. And a rope wound around the pulley in a state of being connected to the end of the pulley.

  According to a third aspect of the present invention, in the material testing machine according to the first aspect, the elastic member deformation mechanism is disposed in a direction parallel to a moving direction of the moving member, and is provided at one end of the elastic member. A connected first rack, a second rack facing the first rack in a direction parallel to the first rack, and fixed to the apparatus main body; the first rack and the second rack; A pinion member that meshes simultaneously.

  According to a fourth aspect of the present invention, in the material testing machine according to the first aspect, the elastic member deformation mechanism includes a fulcrum supported by a support member that moves together with the moving member, and an end that can swing on the apparatus main body. And a lever pivotally supported by the fulcrum with the other end fixed to the end of the elastic member in a swingable state.

  According to the first to fourth aspects of the invention, it is possible to execute an accurate material test by canceling the force applied to the test force by the deformation of the bellows with a simple mechanical configuration. .

1 is a schematic diagram of a material testing machine according to a first embodiment of the present invention. 3 is a plan view showing the arrangement of each part with respect to a moving plate 18. FIG. It is a schematic diagram of the material testing machine which concerns on 2nd Embodiment of this invention. It is a schematic diagram showing a pinion member used in a modification of the second embodiment together with a first rack and a second rack. It is a schematic diagram of the material testing machine which concerns on 3rd Embodiment of this invention. It is a schematic diagram of 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 a first embodiment of the present invention.

  The material testing machine according to the present invention includes a base 11 and a pair of frames 12 that are erected on the base 11 and are connected to each other by a yoke 13 at the top. A pair of screw rods that rotate in synchronization with a drive mechanism (not shown) is disposed in the frame 12. Nuts provided at both ends of the cross head 14 are screwed to these screw rods, and the cross head 14 is moved up and down by the pair of screw rods rotating synchronously. By raising and lowering the cross head 14, a test force is applied to the test piece as will be described later.

  A decompression chamber 21 is disposed on the base 11. The decompression chamber 21 is connected to a decompression mechanism 20 such as a vacuum pump. A platen 25 is disposed on the bottom surface of the decompression chamber 21. An opening 28 is formed in the upper wall of the decompression chamber 21. The rod 23 enters the decompression chamber 21 through the opening 28. A platen 24 is attached to the lower end of the rod 23. The test piece to be subjected to the compression test is pressed by the platen 24 and the platen 25 disposed on the bottom surface of the decompression chamber 21.

  The upper end of the rod 23 is fixed to a disc-shaped moving plate 18. The moving plate 18 is connected to a pair of suspension members 17 and a support member 16 that supports these suspension members 17. The support member 16 is connected to the crosshead 14 via the load cell 15.

  A pair of support bars 19 are erected on the upper surface of the decompression chamber 21, and a support plate 22 is disposed above the support bars 19. A substantially cylindrical bellows 26 is disposed between the lower surface of the support plate 22 and the upper surface of the moving plate 18. A substantially cylindrical bellows 27 is disposed between the lower surface of the moving plate 18 and the upper surface of the decompression chamber 21 so as to surround the rod 23. The bellows 26 disposed above the moving plate 18 and the bellows 27 disposed below the moving plate 18 are both made of metal, have the same natural length, and have the same spring constant.

  FIG. 2 is a plan view showing the arrangement of each part with respect to the moving plate 18.

  A rod 23 is connected to the center of the moving plate 18 that is circular in plan view, and bellows 26 and bellows 27 are disposed on both the upper and lower sides of the moving plate 18 so as to surround the rod 23. In the inner region of the bellows 26, 27, a pair of holes 29 penetrating the moving plate 18 for communicating the internal space of the bellows 26 and the internal space of the bellows 27 are formed. In addition, a pair of support bars 19 are slidably inserted outside the bellows 26 and 27, and a pair of suspension members 17 are disposed at positions outside the support bars 19. A pair of springs 35 to be described later are disposed at positions outside these suspension members 17.

  As described above, the moving plate 18 is formed with a pair of holes 29 that communicate the internal space of the bellows 26 and the internal space of the bellows 27. In addition, the inner diameter of the opening 28 formed in the decompression chamber 21 is larger than the outer diameter of the rod 23, and the interior of the decompression chamber 21 and the inner space of the bellows 27 communicate with each other at the outer periphery of the rod 23. Yes. Therefore, the support plate 22 and the pair of bellows 26 and 27 form a space communicating with the decompression chamber 21 on the outer periphery of the rod 23.

  As shown in FIG. 1, a pair of springs 35 as elastic members according to the present invention are disposed on the moving plate 18. The lower end portion of the spring 35 is in contact with the surface of the moving plate 18, and the upper end portion is covered with a pressing plate 36.

  A pair of support rods 31 are suspended from the cross head 14. A pulley 33 is disposed at the lower end of the support rod 31 and is rotatable about a shaft 32 provided on the support rod 31. The pulley 33 has one end connected to a yoke 13 as a device main body and the other end connected to a pressing plate 36 disposed at an end portion of a spring 35 as a cable body according to the present invention. 34 is wound.

  Here, the “apparatus main body” in this specification means a fixed portion that does not move in the entire area of the apparatus installed on the floor surface, including the frame 12 and the yoke 13. One end of the wire 34 may be fixed to the base 11 or the frame 12 via some direction changing member instead of the yoke 13. In short, the wire 34 may be fixed in a state in which one end thereof does not move while being wound around the pulley 33.

  In the material testing machine having such a configuration, when the cross head 14 is lowered to lower the platen 24 via the rod 23, the moving plate 18 and the pulley 33 connected to the cross head 14 are 14 is lowered by the same distance as the descending distance of the crosshead 14. For this reason, the spring 35 disposed on the moving plate 18 also descends by the same distance as the descending distance of the cross head 14 in synchronization with the cross head 14. On the other hand, since one end of the wire 34 wound around the pulley 33 is connected to the yoke 13 that does not move, the pressing plate 36 connected to the other end of the wire 34 is pulled by the wire 34, thereby The head 14 is lowered by a distance twice the descending distance of the head 14. As a result, the spring 35 that descends in synchronization with the crosshead 14 is compressed by the same distance as the descending distance of the crosshead 14. Accordingly, the moving plate 18 receives a downward force by the spring 35.

  On the other hand, when the moving plate 18 is lowered together with the cross head 14, the bellows 26 is extended and the bellows 27 is contracted. For this reason, the moving plate 18 receives an upward force from the bellows 26 and the bellows 27 based on the spring constants of the bellows 26 and the bellows 27.

  Here, in this material testing machine, the spring constant of the spring 35 is set so that the spring constant of the bellows 26 and 27 and the spring constant of the pair of springs 35 are the same. By adopting such a configuration, a downward force that balances the upward force applied to the moving plate 18 from the bellows 26 and the bellows 27 as the moving plate 18 descends is applied from the pair of springs 35 to the moving plate 18. Will be granted. For this reason, the upward force from the bellows 26 and the bellows 27 generated with the movement of the moving plate 18 is canceled, and it is possible to prevent the test force measured by the load cell 15 from being affected.

  When a material test is performed by applying a test force to a test piece under reduced pressure using the material testing machine having the above-described configuration, the inside of the reduced pressure chamber 21 is decompressed by the decompression mechanism 20. Then, by lowering the cross head 14, the platen 24 is lowered via the suspension member 17, the moving plate 18 and the rod 23, and a test force is applied to the test piece disposed between the platens 24 and 25. At this time, regardless of the movement of the moving plate 18, the volume of the sealed space in the outer peripheral portion of the rod 23 formed by the support plate 22, the pair of bellows 26 and 27, and the decompression chamber 21 is always constant. For this reason, even if the amount of the rod 23 entering the inside of the decompression chamber 21 increases, the pressure in the decompression chamber 21 can be kept constant.

  During the material test, the bellows 26 and 27 are deformed as the moving plate 18 is lowered together with the platen 24. The upward force applied to the moving plate 18 due to the deformation of the bellows 26 and 27 is generated by the pair of springs 35 contracting by a length corresponding to the moving amount of the moving plate 18, and the downward force to the moving plate 18. Offset by power. As a result, the force measured by the load cell 15 and the test force applied to the test piece can be matched, and an accurate material test can be executed.

  In the embodiment described above, a configuration is adopted in which the spring 35 is compressed by the same distance as the descending distance of the crosshead 14 by the pulley apparatus having the single pulley 33. However, the spring 35 may be compressed by a distance larger than the descending distance of the cross head 14 by using a combination pulley mechanism having a plurality of pulleys. In the case of adopting such a configuration, since a spring having a small spring constant can be used, the adjustment can be performed more accurately.

  Next, another embodiment of the present invention will be described. FIG. 3 is a schematic diagram of a material testing machine according to the second embodiment of the present invention. In addition, about the member similar to 1st Embodiment mentioned above, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  The material testing machine according to the first embodiment described above includes a pulley 33 and a wire 34 as an elastic member deformation mechanism that deforms the spring 35 in the same direction as the moving plate 18 as the moving plate 18 moves. A pulley mechanism is used. On the other hand, the material testing machine according to the second embodiment employs an elastic member deformation mechanism including the first rack 41, the second rack 42, and the pinion 43.

  The material testing machine according to the second embodiment is arranged with its tooth surface facing a direction parallel to the moving direction of the cross head 14 and the moving plate 18 with its lower end connected to the upper end of the spring 35. A first rack 41 provided, a second rack 42 that faces the first rack 41 in a direction parallel to the first rack 41 and is fixed to the frame 12 constituting the apparatus main body, and a first rack 41 and a second rack 42, and a pinion 43 that meshes simultaneously. The first rack 41 is supported by a guide member (not shown) so as to be movable up and down. Further, the pinion 43 rotates around a support shaft provided on a support rod 39 that hangs down from the cross head 14. Other configurations are the same as those of the material testing machine according to the first embodiment described above.

  In the material testing machine according to the second embodiment, when the cross head 14 is lowered to lower the platen 24 via the rod 23, the moving plate 18 and the pinion 43 connected to the cross head 14 are crossed. In synchronization with the head 14, the head descends the same distance as the descending distance of the cross head 14. Since the pinion 43 meshes with the second rack 42, the pinion 43 rotates as the pinion 43 descends. As the pinion 43 is lowered and rotated, the first rack 41 is lowered by a distance twice as long as the cross head 14 is lowered. As a result, the spring 35 that descends in synchronization with the crosshead 14 is compressed by the same distance as the descending distance of the crosshead 14. As a result, the moving plate 18 receives a downward force by the spring 35.

  Also in the material testing machine according to the second embodiment, the upward force generated on the moving plate 18 due to the deformation of the bellows 26 and 27 is a length corresponding to the amount of movement of the moving plate 18 by the pair of springs 35. This offsets the downward force on the moving plate 18 caused by shrinking only. As a result, the force measured by the load cell 15 and the test force applied to the test piece can be matched, and an accurate material test can be executed.

  In the material testing machine according to the second embodiment, not only when the cross head 14 is lowered, but also when the cross head 14 is raised, the moving plate 18 rises to raise the bellows 26 and the bellows. The force that balances the force applied from 27 to the moving plate 18 can be applied from the pair of springs 35 to the moving plate 18. For this reason, it is also possible to execute a tensile test on the test piece by using a gripping tool instead of the platens 24 and 25.

  That is, in the material testing machine according to the second embodiment, when the cross head 14 is raised to raise the rod 23, the moving plate 18 and the pinion 43 connected to the cross head 14 are Synchronously, it rises by the same distance as that of the crosshead 14. Since the pinion 43 meshes with the second rack 42, the pinion 43 rotates as the pinion 43 rises. As the pinion 43 is lifted and rotated, the first rack 41 is lifted by a distance twice as long as the cross head 14 is lifted. As a result, the spring 35 rising in synchronism with the cross head 14 is extended by the same distance as the rising distance of the cross head 14. As a result, the moving plate 18 receives an upward force by the spring 35.

  Accordingly, the downward force applied to the moving plate 18 due to the deformation of the bellows 26 and 27 is caused by the pair of springs 35 extending upward by a length corresponding to the moving amount of the moving plate 18. Is offset by the power of As a result, when the tensile test is executed, the force measured by the load cell 15 can be matched with the test force applied to the test piece, and an accurate material test can be executed.

  In the second embodiment described above, a configuration in which the single pinion 43 is engaged with the first rack 41 and the second rack 42 at the same time to compress or expand the spring 35 by the same distance as the descending distance of the crosshead 14. Adopted. However, the spring 35 may be compressed or expanded by a distance larger than the descending distance of the cross head 14.

  FIG. 4 is a schematic view showing the pinion member 46 used in such a modification of the second embodiment together with the first rack 41 and the second rack 42.

  In this modification, instead of the pinion 43 according to the second embodiment, a first pinion 45 and a pinion in which a second pinion 44 having a smaller number of teeth than the first pinion 45 is fixed in a coaxial state. Member 46 is used. The first pinion 45 meshes with the first rack 41. Further, the second pinion 44 meshes with the second rack 42. When such a configuration is adopted, the spring 35 can be compressed or expanded by a distance larger than the descending distance of the cross head 14 by the action of the pinion member 46. For this reason, a spring having a small spring constant can be used, and the adjustment can be performed more accurately.

  Next, still another embodiment of the present invention will be described. FIG. 5 is a schematic diagram of a material testing machine according to a third embodiment of the present invention. In addition, about the member similar to 1st, 2nd embodiment mentioned above, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

  In the material testing machine according to the third embodiment, the lever 53 is used as an elastic member deformation mechanism that deforms the spring 35 in the same direction as the moving plate 18 as the moving plate 18 moves.

  The material testing machine according to the third embodiment includes a lever 53 that swings around a fulcrum 52 that is supported by a lower end portion of a support rod 51 that hangs down from the cross head 14. One end of the lever 53 is fixed to the frame 12 constituting the apparatus main body so as to be swingable about the shaft 55. The other end of the lever 53 is fixed so as to be swingable about a shaft 54 connected to the upper end of the spring 35. Here, the shaft 55 is movable with respect to the frame 12 by a slight distance in the horizontal direction. The lever 53 may be relatively movable with respect to the shaft 55 by a slight distance in the horizontal direction. The distance between the fulcrum 52 and the shaft 55 is the same as the distance between the fulcrum 52 and the shaft 54. Other configurations are the same as those of the material testing machine according to the first and second embodiments described above.

  In the material testing machine according to the third embodiment, when the cross head 14 is lowered to lower the platen 24 via the rod 23, the moving plate 18 and the support rod 51 connected to the cross head 14 are In synchronism with the cross head 14, the cross head 14 descends by the same distance as the descending distance. One end of a lever 53 that swings around a fulcrum 52 supported by the lower end of the support rod 51 is fixed to the frame 12 by a shaft 55, and the distance between the fulcrum 52 and the shaft 55 is the distance between the fulcrum 52 and the shaft. Therefore, the shaft 54 at the other end of the lever 53 descends by a distance twice as long as the descending distance of the crosshead 14 as the support rod 51 descends.

  At this time, the spring 35 is lowered together with the moving plate 18 by the same distance as the descending distance of the cross head 14. For this reason, the spring 35 that descends in synchronization with the crosshead 14 is compressed by the same distance as the descending distance of the crosshead 14. As a result, the moving plate 18 receives a downward force by the spring 35.

  Also in the material testing machine according to the third embodiment, the upward force generated on the moving plate 18 due to the deformation of the bellows 26 and 27 is a length corresponding to the amount of movement of the moving plate 18 by the pair of springs 35. This offsets the downward force on the moving plate 18 caused by shrinking only. As a result, the force measured by the load cell 15 and the test force applied to the test piece can be matched, and an accurate material test can be executed.

  In the material testing machine according to the third embodiment, as in the material testing machine according to the second embodiment, not only when the crosshead 14 is lowered, but also when the crosshead 14 is raised, As the moving plate 18 rises, a force that balances the force applied from the bellows 26 and the bellows 27 to the moving plate 18 can be applied from the pair of springs 35 to the moving plate 18. For this reason, it is also possible to execute a tensile test on the test piece by using a gripping tool instead of the platens 24 and 25.

  Further, in the material testing machine according to the third embodiment, by setting the distance between the fulcrum 52 and the shaft 54 larger than the distance between the fulcrum 52 and the shaft 55, the spring 35 is made smaller than the descending distance of the crosshead 14. A configuration that compresses or expands a large distance is also possible. Even in this case, the spring 35 having a small spring constant can be used, and the adjustment can be performed more accurately.

  In the first, second and third embodiments described above, a pair of the spring 35, the support rod 19, the suspension member 17 and the like are used, but these members are surrounded by the rod 23. Three or more can be used.

  In the above-described embodiment, the spring 35 is used as the elastic member according to the present invention, but other elastic members such as a resin having great elasticity may be used.

  Further, the spring 35 is deformed in the same direction as the moving plate 18 in accordance with the movement of the moving plate 18, whereby a force that balances the force applied from the bellows 26 and 27 to the moving plate is applied from the spring 35 to the moving plate. The elastic member deformation mechanism to be applied is not limited to the above-described configuration, and other mechanical deformation mechanisms such as a mechanism using fluid cylinders having different diameters may be employed.

DESCRIPTION OF SYMBOLS 11 Base 12 Frame 13 Yoke 14 Crosshead 15 Load cell 16 Support member 17 Suspension member 18 Moving plate 19 Support rod 20 Decompression mechanism 21 Decompression chamber 23 Rod 24 Platen 25 Platen 26 Bellows 27 Bellows 28 Opening 29 Hole 31 Support rod 33 Pulley 34 wire 35 spring 39 support rod 41 first rack 42 second rack 43 pinion 44 second pinion 45 first pinion 46 pinion member 51 support rod 52 fulcrum 53 lever 54 shaft 55 shaft

Claims (4)

In a material testing machine that applies a test force to a test piece under reduced pressure to perform a material test,
A vacuum chamber;
A rod for applying a test force to a test piece disposed in the vacuum chamber by entering the vacuum chamber;
A bellows which is disposed so as to surround the rod and forms a space communicating with the decompression chamber on an outer periphery of the rod;
A moving member connected to the rod and the bellows and movable with the rod;
A moving mechanism for applying a test force to the test piece by moving the moving member;
An elastic member coupled to the moving member;
As the moving member moves, the elastic member is deformed in the same direction as the moving member. An elastic member deformation mechanism applied from the elastic member to the moving member;
A material testing machine characterized by comprising: The material testing machine according to claim 1,
The elastic member deformation mechanism is:
A pulley that moves with the moving member;
A cable body wound around the pulley, with one end connected to the apparatus body and the other end connected to the end of the elastic member;
Material testing machine equipped with. The material testing machine according to claim 1,
The elastic member deformation mechanism is:
A first rack disposed in a direction parallel to the moving direction of the moving member and connected to one end of the elastic member;
A second rack facing the first rack in a direction parallel to the first rack and fixed to the apparatus body;
A pinion member that meshes simultaneously with the first rack and the second rack;
Material testing machine equipped with. The material testing machine according to claim 1,
The elastic member deformation mechanism is:
A fulcrum supported by a support member that moves with the moving member;
A lever pivotally supported by the fulcrum, with one end fixed to the apparatus body in a swingable state and the other end fixed to the end of the elastic member in a swingable state;
Material testing machine equipped with.

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