JP2013142610A - Low temperature tensile testing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low temperature tensile testing machine provided with a structure which is capable of excluding an initial load occurring when vacuuming the inside of a case as much as possible.SOLUTION: On the side of a case inside part in a tension axis 31 which goes through the case 11 in the airtight state, there is a load cell 36 for detecting a tension load or a compression load applied to a test piece 12. The tension axis goes through a ring slide member 38 provided on the side of the case inside part of elastic bellows 37 covering an opening 30 formed on one side wall of the case airtight in the airtight and heat insulation state, is adhered to a lid member 37c covering the case outer part side of the bellows airtight via the load cell, and joins the case outside part side of the lid member to drive means 32 which applies the tension load or the compression load to the test piece.

Description

  The present invention relates to a low-temperature tensile tester, and more particularly to a low-temperature tensile tester that performs a tensile test in a state where test pieces of various materials are cooled to an ultra-low temperature.

  As a low-temperature tensile tester, a movable side gripping tool and a fixed side gripping tool each holding a test piece are housed in a vacuum heat insulating housing, and both gripping tools are covered with a radiation shield and a two-stage mechanical refrigeration The first stage cooling head of the machine cools the radiation shield that covers both gripping tools, the second stage cooling head cools the fixed gripping tool and the movable gripping tool, and is arranged in the axial direction of the test piece. A tensile shaft that penetrates one side of the radiation shield and further penetrates one side wall of the housing in an airtight state, and a tensile load or a compressive load is applied to the test piece via the tensile shaft on the outer side of the housing. A driving means for providing, a plurality of support shafts provided in parallel to the axial direction of the test piece from the inner surface of the one side wall of the casing toward the other side wall of the casing, and the other side wall of the casing Fixed plate held by the support shaft at a position away from A fixed holding tool supporting screw member for fixing the fixed holding tool to the fixed plate, and third heat transfer means for transmitting the cold heat of the first stage cooling head of the two-stage mechanical refrigerator to the fixed plate. And a heater provided in a second stage cooling head of the two-stage mechanical refrigerator is known (for example, see Patent Document 1).

JP 2010-286479 A

  The low-temperature tensile tester described in Patent Document 1 is a refrigerant-free tensile tester using a mechanical refrigerator that can cool a specimen to about 5K, and residual stress due to neutron diffraction of various materials at cryogenic temperatures. Measurement, strength / deformation characteristic analysis and internal stress state measurement of the machine part can be performed. This low-temperature tensile testing machine is equipped with a load cell for measuring the loading / unloading process in the elastic region of the tensile test piece. A load corresponding to atmospheric pressure was applied at the initial stage, and this load was also applied to the test piece.

  Therefore, an object of the present invention is to provide a low-temperature tensile testing machine having a structure that can eliminate as much as possible the initial load generated in the load cell when the inside of the casing is evacuated.

  To achieve the above object, the low-temperature tensile tester of the present invention includes a fixed gripping tool that grips one end of a test piece, a movable gripping tool that grips the other end of the test piece, a radiation shield that covers both gripping tools, A vacuum heat insulating housing that houses a radiation shield in a state of covering the gripping tool, a two-stage mechanical refrigerator having a cooling head portion inserted into the housing, and a first-stage cooling of the two-stage mechanical refrigerator First heat transfer means for transferring the cold heat of the head to the radiation shield, and second heat transfer for transferring the cold heat of the second stage cooling head of the two-stage mechanical refrigerator to the fixed gripper and the movable gripper Means, a tension shaft disposed in the axial direction of the test piece and penetrating one side of the radiation shield, and further penetrating one side wall of the casing in an airtight state, and the tension on the outer side of the casing Driving means for applying a tensile load or a compressive load to the test piece via a shaft; A plurality of support shafts provided from the inner surface of the one side wall of the body in the direction of the other side wall of the housing in parallel to the axial direction of the test piece, and at positions away from the other side wall of the housing A fixed plate held by a support shaft, a fixed gripping tool supporting screw member that fixes the fixed gripping tool to the fixed plate, and the cooling heat of the first stage cooling head of the two-stage mechanical refrigerator. In a low-temperature tensile testing machine comprising a third heat transfer means for transmitting to a heater and a heater provided in the second stage cooling head of the two-stage mechanical refrigerator, on the inner side of the casing on the tension shaft A load cell for detecting a tensile load or a compressive load applied to the test piece is provided.

  Furthermore, in the low temperature tensile tester of the present invention, the load cell is attached to a lid member that airtightly covers the exterior side of the extendable bellows in which the tensile shaft airtightly covers an opening formed on one side wall of the housing. And the outside of the casing of the lid member is connected to the driving means.

  According to the low-temperature tensile testing machine of the present invention, the load cell for detecting the load is arranged on the inside of the housing, and therefore, when the inside of the housing is evacuated, the influence due to the load corresponding to the atmospheric pressure generated in the load cell due to the contraction of the bellows. Can be eliminated as much as possible, and high-precision measurement can be performed with no load difference between the loading process and the unloading process. Further, by arranging the load cell on the lid member side of the bellows, it becomes possible to use a load cell for room temperature, and it becomes unnecessary to use an expensive load cell for low temperature.

It is a section front view showing an example of one form of the low-temperature tensile testing machine of the present invention. It is a cross-sectional side view of a housing | casing. It is a side view of a low temperature tensile testing machine.

  This embodiment shows one embodiment of a low-temperature tensile tester for neutron diffraction measurement. As shown in FIG. 1, the low-temperature tensile tester includes a top plate 11a, a bottom plate 11b, a front plate 11c, and a rear plate 11d. , A hexahedron-shaped vacuum heat insulating casing 11 in which six pieces of the left side plate 11e and the right side plate 11f are airtightly joined, a fixed holding tool 13 and a movable holding tool 14 for holding both ends of the test piece 12, respectively, and both holding tools 13 , 14, a radiation shield 15, a fixed plate 16 and a plurality of support shafts 17 for fixing the fixed gripping tool 13 at a predetermined position inside the vacuum heat insulating housing 11, and a movable gripping tool 14. Drive means 18 for moving the test piece 12 in the axial direction (tensile direction) of the test piece 12 and a two-stage mechanical refrigerator 19 for cooling each member in the vacuum heat insulating casing 11.

  A measurement window 20 for irradiating and measuring neutrons is formed at a position corresponding to the position of the test piece 12 on the front plate 11c and the rear plate 11d, and neutron transmission is performed so as to cover the measurement window 20 from the outside. A plate 21 is provided. The neutron transmission plate 21 is formed of a material that can transmit neutrons, and a thin portion 21 a is provided in a portion through which neutrons for irradiation and measurement are transmitted so as to correspond to the measurement window 20.

  The two-stage mechanical refrigerator 19 uses helium to obtain an ultra-low temperature, and includes a first-stage cooling head 19a, a second-stage cooling head 19b that has a lower temperature than the first-stage cooling head 19a, have. The two-stage mechanical refrigerator 19 is airtightly attached to a refrigerator attachment port 22 opened in the top plate 11a of the vacuum heat insulating housing 11 via a refrigerator attachment cylinder 23, and a second-stage cooling head 19b. Is inserted to the vicinity of both grippers 13 and 14 through the cooling head insertion port 24 and the cooling head insertion port 24 provided in the upper surface plate 15 a of the radiation shield 15. Further, the second stage cooling head 19b is provided with a heater 25 for adjusting the temperature of the second stage cooling head 19b.

  The radiation shield 15 is a combination of a top plate 15a, a bottom plate 15b, a pair of front and rear side plates 15c, and a pair of left and right end plate 15d. The top plate 15a is provided with the cooling head insertion port 24. Each end plate 15d is provided with a member through-hole 26 through which a member holding the fixed gripping tool 13 and the movable gripping tool 14 passes. Further, the side plate 15c is formed so as to be detachable from other face plates by fixing means such as screws.

  The radiation shield 15 is a two-stage mechanical refrigerator by a cylindrical connecting member 27 that connects the first-stage cooling head 19 a of the two-stage mechanical refrigerator 19 and the opening edge of the cooling head insertion port 24. It is arranged inside the vacuum heat insulating housing 11 in a state of being suspended by 19. The cylindrical connecting member 27 also serves as a heat transfer member (first heat transfer means) for transmitting the cold heat of the first stage cooling head 19a to the radiation shield 15 via the upper surface plate 15a.

  The fixed grip 13 is fixed to the fixed plate 16 via a fixed grip support screw member 28. The fixed plate 16 is farthest from the installation position of the fixed plate 16 by the four support shafts 17. It is fixed to one side wall (left side wall 11e in the present embodiment) of the housing 11 at the position.

  At four locations on the inner surface side of the left side wall 11e, female screw holes into which a male screw 17a formed on one end portion (the end portion on the left side wall 11e side) of the support shaft 17 is screwed are formed in a non-penetrating state. The shaft 17 is implanted in a direction parallel to the axial direction of the test piece 12 by screwing the male screw 17a into the female screw hole.

  At the four corners of the fixing plate 16 are formed through holes through which the male screw 17b formed at the other end of the support shaft 17 (the end on the right side wall 11f side) passes, and the male screw that passes through each through hole. The fixing plate 16 is fixed in a direction perpendicular to the axial direction of the test piece 12 by screwing the nuts 17c to the tip portions of the 17b. At this time, an interval of several millimeters to several tens of millimeters is provided between the stationary plate 16 and the radiation shield 15 so that the stationary plate 16 and the radiation shield 15 are not in contact with each other.

  Further, a through hole through which the base end portion of the fixed gripping tool supporting screw member 28 passes is formed in the center portion of the fixing plate 16 and passes through the member through hole 26 of the radiation shield 15 to be further fixed. The fixed gripping tool supporting screw member 28 penetrating the through hole of the plate 16 is tightened with a pair of nuts 29, 29 from both sides of the fixing plate 16, so that the fixed gripping tool supporting screw member 28 is fixed to the fixed plate 16. The screw member 28 for supporting the fixed gripper can be adjusted in the axial direction by being fixed vertically and loosening the nuts 29 and 29. The fixed gripping tool 13 is fixed by screwing a female thread portion formed on the base side of the fixed gripping tool 13 to the distal end portion of the fixed gripping tool supporting screw member 28 and tightening with a fixing nut 28a. The fixed gripping tool 13 having a gripping portion 13a corresponding to 12 is formed so as to be attachable / detachable.

  The driving means 18 of the movable gripping tool 14 is disposed in the axial direction of the test piece 12 and passes through the member through-hole 26 of the radiation shield 15 and the opening 30 provided in the left side plate 11e of the housing 11. A tension shaft 31 penetrating inward and outward and a drive device 32 arranged outside the housing 11 are provided. The tension shaft 31 includes a movable gripping tool mounting shaft 33 to which the movable gripping tool 14 is mounted at the tip, a screw shaft 35 that is screwed into the female screw member 34 of the driving device 32, and a load cell 36 provided at an intermediate portion of the tensioning shaft 31. And.

  The movable gripping tool 14 is fixed by screwing a female thread portion formed on the base side of the movable gripping tool 14 to a male screw portion 33a formed at the distal end portion of the movable gripping tool mounting shaft 33 and tightening with a fixing nut 33b. The movable gripping tool 14 having the gripping portion 14a corresponding to the test piece 12 is formed in a state where it can be attached and detached.

  The opening 30 is provided with a bellows 37 that covers the opening 30 in an airtight manner, allows the movement of the tension shaft 31 in the axial direction, and does not affect the load fluctuation at all. A ring-shaped sliding member 38 that supports the movable gripper attachment shaft 33 and penetrates in an axial direction is arranged at the end of the cylindrical portion 37a disposed on the inside of the housing of the bellows 37. It is installed. Further, a lid member 37c that covers the outside of the bellows 37 in an airtight manner is attached to the outside of the bellows 37 via a flange 37b. One end of the screw shaft 35 is fixed to the lid member 37c, and the load cell 36 is disposed inside the housing of the lid member 37c.

  The driving device 32 is fixed to the left side wall 11 e of the housing 11 through two driving device support shafts 39 and a driving device mounting plate 40. Female screw holes for screwing male screws 39a formed at the base end of the drive device support shaft 39 are formed in two positions on the outer surface side of the left side wall 11e in a non-penetrating manner, and the male screws 39a are formed in both female screw holes. By screwing, the drive device support shaft 39 is fixed to the left side wall 11e in a state parallel to the axial direction of the test piece 12. A through hole through which a male screw 39b formed at the tip of the drive device support shaft 39 passes is formed at two locations on the drive device mounting plate 40, and a nut 39c is screwed onto the male screw 39b that passes through the through hole. Thus, the drive device mounting plate 40 is fixed in a direction perpendicular to the axial direction of the test piece 12. The drive device mounting plate 40 has a worm gear 41 screwed to a worm wheel 34a provided on the outer periphery of the female screw member 34 rotatably held by a bearing member 40a, and the worm gear 41 is rotationally driven via a joint 42. A motor 43 is provided.

  Between the first-stage cooling head 19 a of the two-stage mechanical refrigerator 19 and the fixed plate 16, a heat transfer member for transmitting the cold heat of the first-stage cooling head 19 a to the fixed plate 16 (third (Heat transfer means) 44 is attached via heat transfer member fittings 44a and 44b. Further, between the first stage cooling head 19a and the movable gripper mounting shaft 33, a heat transfer member 45 for transmitting the cold heat of the first stage cooling head 19a to the movable gripper mounting shaft 33 is a heat transfer member. It is attached via fixtures 45a and 45b.

  Further, between the second stage cooling head 19b of the two-stage mechanical refrigerator 19 and the fixed gripping tool 13 and the movable gripping tool 14, the cold heat of the second stage cooling head 19b is transferred to the fixed gripping tool 13 and the movable gripping tool. Heat transfer members (second heat transfer means) 46 for transmitting to each of 14 are attached via heat transfer member attachments 46a and 46b, and the second stage cooling head 19b and the fixed gripper 13 have a temperature Each sensor (not shown) is attached. The heat transfer member 45 can be formed so as to cool the end face plate 15 d of the radiation shield 15 simultaneously with the movable gripper mounting shaft 33.

  Further, outside of the vacuum heat insulating casing 11, the operating state of the two-stage mechanical refrigerator 19 is controlled based on the temperature of the second-stage cooling head 19b and the temperature of the fixed gripper 13 measured by the temperature sensor. Control means (not shown) for performing temperature control for controlling the amount of heat generated by the heater 25, or for controlling the motor 43 of the drive means 18 based on the measured load of the load cell 36. ) Is provided. In the low-temperature tensile testing machine shown in this embodiment, the driving device 32 is provided with a manual operation unit 47 that can manually move the movable gripping tool 14. Furthermore, an eyebolt 48 used when lifting the low temperature tensile tester is provided on the upper part of the vacuum heat insulating casing 11.

  Note that the fixed gripping tool 13 and the movable gripping tool 14 can be formed of stainless steel, but the test piece 12 can be effectively cooled by being formed of copper having good thermal conductivity. 15 and the fixing plate 16 can also be made of a metal having good thermal conductivity, for example, aluminum (including an alloy, the same shall apply hereinafter) to enhance the radiation shielding effect. Similarly, it is preferable that the cylindrical connecting member 27 and the heat transfer members 44, 45, and 46 are also formed of a metal having good thermal conductivity. In particular, the heat transfer members 44, 45, and 46 take into account the mounting state. It is preferable to use a bundle of a plurality of conducting wires. Further, the neutron transmission plate 21 is preferably formed of aluminum that easily transmits neutrons, and the neutron permeability can be improved by providing the thin portion 21a. Other structural members can be formed of general stainless steel, and the heat insulating structure of the vacuum heat insulating casing 11 can be combined with other heat insulating structures.

  The two-stage mechanical refrigerator 19 can use any type of refrigerator as long as a desired low temperature can be obtained, and a plurality of two-stage mechanical refrigerators 19 can be installed. . Furthermore, the structure of the heater 25 can be any structure as long as the second-stage cooling head 19b can be overheated, and the heater heat generation amount can be controlled by any control means.

  Next, a procedure for performing neutron diffraction measurement of the test piece 12 using the low temperature tensile tester shown in this embodiment will be described. First, when the inside of the vacuum heat insulating housing 11 is at room temperature and normal pressure, the front plate 11c of the vacuum heat insulating housing 11 is removed to open the front surface of the housing 11, and the side plate 15c on the front side of the radiation shield 15 is further opened. The fixed gripping tool 13 and the movable gripping tool 14 are exposed by being removed, and the fixed gripping tool 13 and the movable gripping tool 14 are exchanged for one corresponding to the test piece 12 as necessary.

  Next, the nut 29 of the fixed gripping tool supporting screw member 28 is operated to move the fixed gripping tool supporting screw member 28 in an appropriate axial direction, and the fixed gripping tool 13 is moved to a position corresponding to the length of the test piece 12. Fix it. Further, while the motor 43 of the driving means 18 is operated or the manual operation unit 47 is operated to move the movable gripping tool 14 to an appropriate position, the fixed gripping tool 13 and the gripping portions 13a and 14a of the movable gripping tool 14 are moved. Grip both ends of the test piece 12. When the gripping part is a screw-in type, both ends of the test piece 12 are screwed and the test piece 12 is held by the fixed gripping tool 13 and the movable gripping tool 14. Further, a strain gauge or an extensometer can be attached to the test piece 12 as necessary.

  After setting the test piece 12 to the fixed gripping tool 13 and the movable gripping tool 14, the side plate 15c is attached, the radiation shield 15 is returned to the state covering the test piece 12 and the gripping tools 13, 14, and then the front plate 11c is attached. Thus, the vacuum heat insulating casing 11 is hermetically sealed. At this time, the neutron transmission plate 21 can be replaced with one corresponding to the test piece 12 as necessary. In addition, the vacuum heat insulation housing | casing 11 and the radiation shield 15 can also open | release both front and rear surfaces in consideration of operativity.

  Next, a vacuum pump (not shown) is operated to start evacuation in the vacuum heat insulating casing 11, and the inside of the vacuum heat insulating casing 11 reaches a preset vacuum degree, and it is confirmed that there is no load fluctuation in the load cell 36. After that, the operation of the two-stage mechanical refrigerator is started to cool each part in the vacuum heat insulating casing 11. The temperature of each part, in particular, the temperature of the test piece 12 is controlled based on signals from temperature sensors provided in the second stage cooling head 19b and the fixed gripper 13, and is controlled so as to maintain a preset measurement temperature. The means controls the amount of heat generated by the heater 25. For example, when the temperature of the test piece 12 cooled from the second stage cooling head 19b through the heat transfer member 46 and the gripping tools 13 and 14 is set to 5K, the first stage cooling head through the cylindrical connecting member 27 is used. The temperature of the radiation shield 15 to be cooled and the temperature of the fixed plate 16 and the movable gripper mounting shaft 33 to be cooled via the heat transfer members 44 and 45 are maintained at about 70K.

  In this cooled state, the fixed gripping tool supporting screw member 28 is attached to the fixed plate 16 cooled via the heat transfer member 44, and the fixed plate 16 is separated from the fixed plate 16 by the support shaft 17. Since it is attached to the left side plate 11e of the vacuum heat insulating housing 11, it is possible to eliminate heat penetration from the outside into the fixed gripping tool supporting screw member 28 via the vacuum heat insulating housing 11 as much as possible. Can be held in a state of being cooled to ultra-low temperature. Similarly, by cooling the movable gripper attachment shaft 33 via the heat transfer member 45, it is possible to eliminate heat penetration from the movable gripper attachment shaft 33 into the fixed gripper 13 as much as possible.

  After the test piece 12 reaches the set temperature, the motor 43 is operated by the control device, and the movable gripping tool 14 is moved in the axial direction via the tension shaft 31, thereby applying a tensile load or a compressive load to the test piece 12. . The tensile load or the compressive load applied to the test piece 12 is detected by the load cell 36, and the value measured by the load cell 36 is transmitted to the control means and recorded at any time.

  Irradiation of neutrons is performed by introducing thermal neutrons generated continuously or in a pulse form from a neutron generation source such as a nuclear reactor to the test piece 12 through a neutron transmission plate 21 using a neutron conduit and a monochromator crystal. . Neutron irradiation is performed until signals from the test piece 12 are sufficiently integrated. The dose per unit time depends on the ability of the neutron generation source. The measurement of the amount of neutron irradiation uses monochromatic neutrons. The diffracted neutrons from the test piece 12 are obtained by observing the spectrum of the neutron intensity with respect to the diffraction angle by a neutron detector installed near the diffraction angle of the test piece 12. taking measurement. Moreover, when using pulsed neutrons of white light, the neutron flight time and neutron intensity spectra are measured by a group of neutron detectors facing each other.

  The stress applied to the test piece 12 is measured by the measured value of the load cell 36 and the cross-sectional area of the test piece 12, and the lattice spacing of the crystals constituting the test piece 12 is determined by neutron diffraction at an arbitrary load, and the neutron diffraction phenomenon is measured. It can be measured using. In the case of an amorphous test piece, a halo pattern due to a neutron diffraction phenomenon can be measured. Furthermore, the elastic constant of the test piece 12 can also be obtained from the stress-strain diagram by calculating the strain amount from the obtained lattice spacing. Further, by attaching a strain gauge or extensometer to the test piece 12, deformation information of the entire test piece can be measured simultaneously with neutron diffraction.

  When the measurement is performed in this manner, the fixing plate 16 and the radiation shield 15 are arranged in a non-contact state, so that the radiation shield 15 is moved in the axial direction of the test piece 12 due to the thermal expansion and contraction of the cylindrical connecting member 27. It is possible to eliminate the influence of moving in the direction perpendicular to the measured value. In the unloading process, which is a process of gradually reducing the load applied to the test piece 12, the measured value in the loading process, which is a process of applying a load to the test piece 12. It is possible to prevent an error from occurring with the measured value. As a result, high-accuracy measurement at ultra-low temperatures is possible.

  Furthermore, by arranging the load cell 36 on the inside of the housing of the bellows 37, when the inside of the housing 11 is evacuated, the influence due to the load corresponding to the atmospheric pressure generated in the load cell 36 due to the contraction of the bellows 37 is prevented. It is possible to eliminate as much as possible, and it is possible to perform highly accurate measurement without causing a load difference between the loading process and the unloading process of the test piece 12. Further, by arranging the load cell 36 near the lid member 37c in the bellows 37 arranged on the room temperature side, even if the inside of the housing 11 is cooled to an extremely low temperature, the temperature drop of the load cell 36 may be made slight. it can. Thereby, it becomes possible to use a load cell for room temperature, and it becomes unnecessary to use an expensive load cell for low temperature.

  As described above, the low-temperature tensile testing machine of the present invention generates residual stress (external force such as tension, compression, bending, heat treatment, etc.) due to neutron diffraction of various materials, and is retained even after the external force is removed. By measuring the stress) in an ultra-low temperature state of 5K or less, it is possible to know the residual stress distribution inside the material and the state of distortion, etc. Steel, metal, automobiles / parts, heavy industry / machinery, power / gas, construction / It can be used for the purpose of strengthening various materials such as civil engineering and ensuring safety, and can be used in various industrial fields.

  DESCRIPTION OF SYMBOLS 11 ... Vacuum insulation housing, 11a ... Top plate, 11b ... Bottom plate, 11c ... Front plate, 11d ... Rear surface plate, 11e ... Left side plate, 11f ... Right side plate, 12 ... Test piece, 13 ... Fixed gripping tool, 13a ... Grip 14, movable gripping tool, 14 a, gripping portion, 15, radiation shield, 15 a, top plate, 15 b, bottom plate, 15 c, side plate, 15 d, end plate, 16, fixed plate, 17, support shaft, 17 a,. Male screw, 17b ... Male screw, 17c ... Nut, 18 ... Driving means, 19 ... Two-stage mechanical refrigerator, 19a ... First stage cooling head, 19b ... Second stage cooling head, 20 ... Measurement window, 21 ... Neutron transmission Plate, 21a ... Thin wall part, 22 ... Refrigerator attachment port, 23 ... Refrigerator attachment tube, 24 ... Cooling head insertion port, 25 ... Heater, 26 ... Member through-hole, 27 ... Cylindrical connecting member (first heat transfer means) ) 28... Screw member for supporting the fixed gripping tool, 8a ... fixed nut, 29 ... nut, 30 ... opening, 31 ... tension shaft, 32 ... drive device, 33 ... movable gripper mounting shaft, 33a ... male screw portion, 33b ... fixed nut, 34 ... female screw member, 34a ... worm wheel 35 ... Screw shaft, 36 ... Load cell, 37 ... Bellows, 37a ... Cylindrical part, 37b ... Flange, 37c ... Lid member, 38 ... Ring-shaped sliding member, 39 ... Drive support shaft, 39a ... Male screw, 39b ... Male screw, 39c ... nut, 40 ... drive device mounting plate, 40a ... bearing member, 41 ... worm gear, 42 ... joint, 43 ... motor, 44 ... heat transfer member (third heat transfer means), 44a, 44b ... heat transfer member 45, heat transfer member, 45a, 45b ... heat transfer member mount, 46 ... heat transfer member (second heat transfer means), 46a, 46b ... heat transfer member mount, 47 ... manual operation unit, 48 ... Aibo Door

Claims (2)

  A vacuum-insulated housing that houses a fixed gripping tool that grips one end of the test piece, a movable gripping tool that grips the other end of the test piece, a radiation shield that covers both gripping tools, and a radiation shield that covers the gripping tool. And a two-stage mechanical refrigerator having a cooling head portion inserted into the housing, and first heat transfer means for transmitting the cold heat of the first-stage cooling head of the two-stage mechanical refrigerator to the radiation shield. A second heat transfer means for transmitting the cold heat of the second stage cooling head of the two-stage mechanical refrigerator to the fixed gripper and the movable gripper, and the radiation shield disposed in the axial direction of the test piece A tension shaft that penetrates one side of the housing and further penetrates one side wall of the housing in an airtight state, and a drive that applies a tensile load or a compressive load to the test piece via the tension shaft on the outside of the housing Means and an axial direction of the test piece from the inner surface of the one side wall of the casing. A plurality of support shafts provided in parallel toward the other side wall of the housing, a fixed plate held by the support shaft at a position away from the other side wall of the housing, and the fixing to the fixed plate. A fixed gripping tool supporting screw member for fixing the gripping tool, third heat transfer means for transmitting cold heat of the first stage cooling head of the two-stage mechanical refrigerator to the fixed plate, and the two-stage mechanical type In a low-temperature tensile testing machine provided with a heater provided in a second stage cooling head of a refrigerator, a tensile load or a compressive load applied to the test piece is detected on the inner side of the casing on the tensile shaft. A low-temperature tensile testing machine characterized by a load cell.   The tension shaft is fixed to the lid member that airtightly covers the exterior side of the expandable bellows that airtightly covers the opening formed on one side wall of the housing via the load cell, and the housing of the lid member 2. The low temperature tensile testing machine according to claim 1, wherein an external side is connected to the driving means.

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