JP2020134186A - Mechanical property test unit - Google Patents

Abstract

To perform a test under a desired low temperature environment including a room temperature to a cryogenic temperature, for a test such as a low strain rate tension test (SSRT test).SOLUTION: There is provided a low strain rate tension test unit 11 for performing test of a test piece 12 under a low temperature environment in a state of storing a test piece peripheral part 15 whose center is the test piece 12, in a test container 16 comprising a refrigerant channel and capable of being controlled in a temperature by the refrigerant, the low strain rate tension test unit has an external heat insulation container 14 having an inner space 14a which is formed into a size so as to store the test container 16 and having heat insulation property. The test container 16 can be suspended and supported, and the external heat insulation container 14 is formed into a cylindrical shape with a bottom and supported in a vertically movable manner by movement means 17. The movement means 17 moves the external heat insulation container 14 for switching a positional relationship between a surrounding position relationship in which the external heat insulation container 14 surrounds the test container 16, and an exposure position relationship in which the external heat insulation container 14 is separated from the test container 16 for exposing the test container 16.SELECTED DRAWING: Figure 1

Description

The present invention relates to, for example, a mechanical property test device capable of performing a low strain rate tensile test (SSRT test) in a low temperature environment, and more particularly to a mechanical property test device capable of testing in a cryogenic environment.

The device of Patent Document 1 below is disclosed as a device for performing a mechanical property test in an extremely low temperature environment. The fracture toughness test apparatus of Patent Document 1 includes a double vacuum insulation dual bottle that houses a test piece attachment and a liquid nitrogen bottle that covers the outside of the double vacuum insulation dual bottle in order to keep the test piece in a cryogenic environment. have. In the double vacuum insulation dual bottle, liquid helium as a cryogenic refrigerant body is sufficiently stored so as to immerse the test piece attachment. Further, a gap is provided between the double vacuum insulation dual bottle and the liquid nitrogen bottle, and liquid nitrogen is sealed in this gap. The liquid nitrogen bottle is made of a heat insulating material.

In this device, the test is performed in a state of being immersed in a cryogenic liquid helium in a double vacuum insulated dual bottle. That is, the test is performed at a cryogenic liquid helium temperature of 268.9 ° C. The outer liquid nitrogen bottle suppresses heat input to the double vacuum insulated dual bottle with the enclosed liquid nitrogen (-195.8 ° C.), thereby suppressing the consumption of expensive liquid helium.

However, the test is performed at the temperature of the cryogenic refrigerant contained in the double vacuum insulation dual bottle, and the test cannot be performed at a higher temperature unless the refrigerant is replaced. Further, since the container for storing liquid helium is a double vacuum heat insulating dual bottle, it cannot be used as a high pressure container and cannot be tested under high pressure conditions.

Japanese Unexamined Patent Publication No. 1-254839

The main invention of the present invention is to enable the test to be performed in a desired low temperature environment (hereinafter referred to as "low temperature") including a room temperature to an extremely low temperature, and also to be performed at a desired low temperature even in a high pressure environment. The purpose.

The means for that is a mechanical property test apparatus that stores the peripheral part of the test piece centering on the test piece in a test container and tests the test piece in an environment of room temperature to low temperature, and houses the test container. An outer heat insulating container having an internal space of a possible size and having heat insulating properties is provided, and the temperature can be controlled by the refrigerant body flowing from the refrigerant body flow path provided in the test container, and the outer heat insulating container or the test The outer insulation is provided by moving at least one of the containers so that the outer insulation container surrounds the test container and the outer insulation container is separated from the test container to expose the test container. It is a mechanical property test apparatus provided with a moving means for relatively moving the container and the test container.

The test container in the above-mentioned surrounding position relationship and exposure position relationship is in a state where the test can be performed. That is, when the test container is composed of a main body member and a lid member, the test container is in a closed state in which these are combined.

In this configuration, when conducting a test at a cryogenic temperature, the outer heat insulating container and the test container are surrounded by a moving means, an extremely low temperature refrigerant body is put into the internal space of the outer heat insulating container, and the test container is cooled. A refrigerant body is circulated in the medium flow path to cool the test container. When conducting a test in a high-pressure environment, a high-pressure container provided with a refrigerant flow path is used as the test container.

According to the present invention, since the outer heat insulating container that can move relative to the position surrounding the test container and the position where the test container is exposed is provided, an appropriate refrigerant body is put into the outer heat insulating container as needed. Therefore, the outer heat insulating container can have a function as a refrigerator. Therefore, the test container can be cooled from the outside to bring the inside of the test container into a low temperature environment at a desired temperature. Further, the temperature of the test container can be adjusted by the refrigerant body flowing from the refrigerant body flow path.

Further, since the test container is cooled from the outside, it is possible to shorten the time and work required for the test preparation for lowering the temperature inside the test container. Moreover, since it is not necessary to use an electrically operated refrigerator, it can contribute to ensuring safety even when a flammable gas is used for the test.

Further, since the test container can be cooled mainly by the flow path of the refrigerant body of the test container and the refrigerant body in the outer heat insulating container, a test container suitable for the desired test environment can be used, and as described above, the test container can be used. When a high-pressure container is used as a medium, the test can be performed at a desired low temperature even in a high-pressure environment.

The figure which shows the schematic structure and system of the low strain rate tensile test apparatus. A partial cross-sectional front view showing the main body of the low strain rate tensile test device. Sectional view of the outer insulation container. Front view of low strain rate tensile test equipment. Top view of the lift. Top view of the outer insulation container. Top view of the lift and the outer insulation container. Top view of the auxiliary plate. Perspective view of the locking member. Top view of the lifting platform when the locking member is attached. A partial cross-sectional front view of a state in which the locking member is locked to the locked portion of the main body member. Front view of the test container and the outer heat insulating container in the exposed positional relationship. Explanatory drawing explaining the support height of the lid member of a test container. A partial cross-sectional front view showing a state in which the main body member of the test container is lowered. A partial cross-sectional front view showing a state when the main body member of the test container is raised. A partial cross-sectional front view showing a state at the time of a test in which there is a surrounding positional relationship.

An embodiment for carrying out the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic structure and system of a low strain rate tensile test device 11 (hereinafter referred to as “test device”) as an example of a mechanical property test device. In this example, in particular, in order to evaluate the hydrogen compatibility of metal materials and the like, a test device for testing in a low-temperature and high-pressure hydrogen gas environment is illustrated.

As shown in FIG. 1, the test apparatus 11 is configured by attaching an outer heat insulating container 14 to an apparatus main body 13 for performing a tensile test of the test piece 12. The apparatus main body 13 stores the test piece peripheral portion 15 centering on the test piece 12 in the test container 16 and performs a tensile test of the test piece 12 in a low temperature environment. The outer heat insulating container 14 has an internal space 14a having a size capable of accommodating the test container 16 and has heat insulating properties.

Further, at least one of the outer heat insulating container 14 and the test container 16 is moved to the test device 11, and the surrounding positional relationship in which the outer heat insulating container 14 surrounds the test container 16 and the outer heat insulating container 14 and the test container 16 are separated from each other for the test. A moving means 17 for relatively moving the outer heat insulating container 14 and the test container 16 is provided in an exposed positional relationship for exposing the container 16.

First, the device main body 13 will be briefly described.

The device main body 13 has a device main body fixing portion 22 that suspends and supports the device main body 13 at a position away from the base 21 at the lower end. The device main body fixing portion 22 is appropriately height-supported by the support column 23. An actuator 24 for applying a tensile force to the test piece 12 is provided above the device main body fixing portion 22, and the tensile force of the actuator 24 is transmitted to the test piece 12 below the device main body fixing portion 22. The pull rod 25 is vertically installed.

The upper portion of the pull rod 25 is supported by a suspension plate portion 27 fixed to the lower end of a rod-shaped suspension member 26 extending downward from the lower surface of the device main body fixing portion 22. The suspension plate portion 27 is provided with an upper end holding portion 27a so that the pull rod 25 can slide. Further, above the pull rod 25, an external load cell 28 and a displacement meter 29 are provided between the device main body fixing portion 22 and the suspension plate portion 27. The external load cell 28 is for detecting the load (pulling force) applied to the pull rod 25, and is provided mainly for ensuring safety. The displacement meter 29 detects the displacement stroke of the pull rod 25 pulled by the actuator 24.

As shown in FIG. 2, an upper holding portion 30 for interpolating the pull rod 25 is provided below the upper end holding portion 27a. The upper holding portion 30 has a built-in seal structure (not shown) for sealing the pull rod 25. The lower tubular portion 30a of the lower portion of the upper holding portion 30 is formed to an appropriate length, and the test container 16 is provided at the lower end. The length of the lower tubular portion 30a of the upper holding portion 30 has a function of separating the above-mentioned seal structure from the test container 16 so that the seal of the seal structure is not unnecessarily cooled.

The test container 16 is composed of a high-pressure container provided with a refrigerant body flow path 16a. Specifically, the test container 16 has a main body member 31 and a lid member 32. The main body member 31 is formed with an accommodating portion 31a for accommodating the test piece 12 and the above-mentioned test piece peripheral portion 15 which is a member around the test piece 12, and an opening 31b which is an entrance / exit of the test piece peripheral portion 15 to the accommodating portion 31a. The main body member 31 has a bottomed tubular shape as a whole, and more specifically, a bottomed cylindrical shape.

A large-diameter portion 31c projecting in the outer peripheral direction is formed in the vicinity of the opening 31b at the upper end, a portion below the large-diameter portion 31c is a cylindrical cylindrical portion 31d, and the lower end of the cylindrical portion 31d is. It is formed in a spherical shape. Since the main body member 31 is a high-pressure container, it is formed to have a sufficient wall thickness, and a spiral groove is formed on the outer peripheral surface of the cylindrical portion 31d. This groove is the above-mentioned refrigerant body flow path 16a.

The formation position of the refrigerant body flow path 16a is set to a position appropriately lowered below the large diameter portion 31c, and the neck portion 31e without the refrigerant body flow path 16a is formed at the upper end portion of the cylindrical portion 31d. An exterior body 33 that covers the outer periphery of the cylindrical portion 31d is fixed to the neck portion 31e.

The outer body 33 has a bottomed cylindrical shape, and has an introduction port 33a at the upper end portion for introducing the refrigerant body into the refrigerant body flow path 16a. Further, the exterior body 33 has an inner peripheral surface 33b in contact with the outer peripheral surface of the portion having the refrigerant body flow path 16a, and a discharge port 33c for discharging the refrigerant body flowing through the refrigerant body flow path 16a is provided at the lower end. It is formed. A flexible hose 34 is connected to the tip of the discharge port 33c (see FIG. 1).

The lid member 32 closes the opening 31b at the upper end of the main body member 31, and is fixed to the lower end flange portion 30b of the lower tubular portion 30a of the upper holding portion 30 described above. The lid member 32 has a supply path 32a and a discharge path 32b that communicate with the opening 31b of the main body member 31. The fluid to be fed into the accommodating portion 31a passes through the supply path 32a.

The lid member 32 and the main body member 31 have a connecting structure with bolts (not shown), and the lid member 32 is removable from the main body member 31.

Since the test container 16 is composed of the lid member 32 and the main body member 31 that are detachable from each other in this way, the test container 16 in which the main body member 31 and the lid member 32 are connected to each other and can be tested is described above. This is the test container 16 when there is an exposed positional relationship with the surrounding positional relationship.

The peripheral portion 15 of the test piece described above is provided at the lower end of the pull rod 25. Therefore, the lid member 32 of the test container 16 is suspended and supported together with the peripheral portion 15 of the test piece. The test piece peripheral portion 15 faces the reaction force base 35 suspended on the lower surface of the lid member 32, one test piece mounting portion 36 fixed to the reaction force base 35, and one test piece mounting portion 36. It has an other test piece mounting portion 37 and an internal load cell 38 provided above the other test piece mounting portion 37.

The internal load cell 38 provided in the peripheral portion 15 of the test piece is for measuring the test load, and detects the load (pulling force) applied to the test piece 12. The internal load cell 38 is selected so that it can be used even in an extremely low temperature and high pressure environment.

The test piece 12 has a rod shape, and the test piece 12 is held by one test piece mounting portion 36 and the other test piece mounting portion 37 in a state where the test piece 12 is extended in the vertical direction.

Although not shown, the test container 16 is provided with a pressure gauge for detecting the pressure in the accommodating portion 31a and a thermometer for detecting the temperature.

As shown in FIG. 1, a high-pressure hydrogen gas 41, a helium compressor 42, a nitrogen gas 43, and a vacuum pump 44 are connected to the supply path 32a of the lid member 32 of the test container 16 described above, and the test container is connected. It is configured so that hydrogen gas, helium gas, and nitrogen gas can be selectively sent into the housing portion 31a of 16. Further, a liquid nitrogen supply source 46 is connected to an introduction port 33a of the exterior body 33 of the main body member 31 of the test container 16 via an inlet side heater block 45. The tip of the hose 34 connected to the discharge port 33c of the exterior body 33 is connected to a nitrogen gas outlet (not shown) that discharges nitrogen gas via the outlet side heater block 47. The inlet side heater block 45 is provided with a heater and has a function of adjusting disturbance temperature fluctuation. The outlet side heater block 47 also has a heater, and has a function of bringing the discharged nitrogen gas to a temperature close to room temperature.

Further, the actuator 24 of the device main body 13 and other necessary members are connected to the control device 48, and the external load cell 28, the displacement meter 29, the thermometer for detecting the temperature inside the test container 16, and the pressure inside the test container 16 are also connected. The thermometer and the internal load cell 38 for detecting the above are connected to the data recording device 49 as shown by a single point chain line in FIG. The data recording device 49 is connected to the control device 48 described above. When the actuator 24 is operated by the control operation by the control device 48 and the tensile test is started, the data recording device 49 normally uses the stroke output signal of the displacement meter 29, the pressure output signal of the pressure gauge, and the thermometer. A temperature output signal and a load output signal of the internal load cell 38 are input to perform predetermined data processing.

Next, the outer heat insulating container 14 will be described.

As shown in FIG. 3, the outer heat insulating container 14 is a vacuum heat insulating container having a vacuum heat insulating layer 14b, and has a bottomed tubular shape having an opening 14c on the upper surface, more specifically, a bottomed cylindrical shape. A vacuum pump 51 for evacuation is connected to the vacuum heat insulating layer 14b (see FIG. 1).

The upper end of the outer heat insulating container 14 has a ring-shaped upper end plate 14d, and the outer peripheral surface of the upper end plate 14d is flush with the outer peripheral surface of the outer heat insulating container 14, but the inner peripheral surface is outer heat insulating. It is located inside the inner peripheral surface of the container 14. That is, the upper end plate 14d projects inward over the entire circumference at the upper end of the outer heat insulating container 14.

As described above, the outer heat insulating container 14 has an internal space 14a large enough to accommodate the test container 16, the diameter thereof is larger than the diameter of the lid member 32 of the test container 16, and the height is the main body member. It is higher than the total height of 31 because, as shown in FIG. 4, the outside of the test container 16 is surrounded by the outer heat insulating container 14. Therefore, the inner diameter of the upper end plate 14d of the outer heat insulating container 14 is set to be larger than the diameter of the lid member 32 of the test container 16.

The bottom surface 14e of the outer heat insulating container 14 is flat and has a shape that allows stable placement. A mounting table 52 is provided at a position on the upper surface of the base 21 on which the outer heat insulating container 14 is placed. The mounting table 52 has a recess 52a that receives the bottom surface 14e of the outer heat insulating container 14, and an inverted conical inclined surface 52b is formed on the outer peripheral edge of the recess 52a.

Further, the outer heat insulating container 14 is provided with an introduction path 53 for introducing a refrigerant body into the internal space 14a (see FIG. 1). The introduction path 53 branches and extends from between the refrigerant body 46 and the inlet side heater block 45.

Since the inner diameter of the upper end surface (upper end plate 14d) of the outer heat insulating container 14 is larger than the outer diameter of the test container 16, it is shown in FIG. 4 in order to close the space between the upper surface of the outer heat insulating container 14 and the test container 16. As described above, the detachable heat insulating lid 54 for closing the internal space 14a of the outer heat insulating container 14 is provided. The heat insulating lid 54 is made of, for example, thick urethane foam. The shape of the heat insulating lid 54 is a thick plate shape having the same annular shape as the space between the outer heat insulating container 14 and the test container 16, and is composed of a member having this shape divided into a plurality of parts in the circumferential direction. The heat insulating lid 54 is formed with appropriate necessary notches that allow the presence of necessary members such as the above-mentioned hose 34 extending from the discharge port 33c at the bottom of the test container 16.

Next, the transportation means 17 will be described.

The moving means 17 moves the outer heat insulating container 14 and the main body member 31 up and down. As shown in FIG. 4, the moving means 17 is for driving the pair of sliders 61 that move up and down along the support columns 23, the lifting platform 62 held between the sliders 61, and the sliders 61. It is composed of a motor 63, a screw shaft 64 that is erected in parallel with a support column 23 and rotates as the motor 63 rotates.

The slider 61 rises and falls along the support column 23 in a preset predetermined range according to the rotation of the screw shaft 64. Necessary members such as the above-mentioned motor 63, a position sensor (not shown) for detecting the elevating position, and an operation switch (not shown) are connected to a control unit (not shown), and the motor 63 is operated. It is driven and controlled by the control unit according to the input from the switch.

A hanging piece 61a is provided at an inner position corresponding between the columns 23 of the slider 61, and an elevating stand 62 is fixed to the lower end of the hanging piece 61a. The height of the hanging piece 61a is a height that avoids interference with a portion above the hanging plate portion 27 when the upper surface of the lifting platform 62 is raised to a position corresponding to the upper end portion of the test container 16.

The shape of the lifting platform 62 is a rectangular parallelepiped frame shape. That is, the rod-shaped body, specifically, the corners of the angle member 62a are arranged at positions corresponding to all the sides constituting the rectangular parallelepiped, and the square window portion 62b is formed on all the surfaces. The sizes of the window portions 62b on the upper and lower two surfaces are the same as each other, and the sizes of the window portions 62b on the other four side surfaces are the same as each other.

The size of the upper and lower two windows 62b is a square slightly larger than the diameter of the outer peripheral surface of the outer heat insulating container 14.

As shown in FIG. 5, two mounting plates 65 are fixed to the upper surface of such an elevating stand 62. The two mounting plates 65 have the same shape as each other, and one diagonally perpendicular corner portion of the square window portion 62b is projected inward to form a curve of a quarter arc in a plan view. Is. That is, when the pair of mounting plates 65 are fixed to the upper surface of the lifting platform 62 in a combined state, the two right-angled portions 65a having a shape corresponding to the square frame on the upper surface of the lifting platform 62 and the inner peripheral edge thereof are formed. It has a substantially triangular overhanging portion 65b that is a curved curve of a quarter arc. In other words, each of the two mounting plates 65 has one right-angled portion 65a and one overhanging portion 65b.

The curves of the inner circumference of the overhanging portion 65b are arcs having the same diameter, and the distance (inner diameter) between the curves of the overhanging portions 65b facing each other is slightly larger than the diameter of the outer peripheral surface of the outer heat insulating container 14.

Both ends of the two mounting plates 65, a portion corresponding to a corner portion on the upper surface of the lifting platform 62, and an intermediate portion between the portions corresponding to the corner portions are fixed with bolts 66. An appropriately thick plate-shaped auxiliary material 67 is integrally fixed to the upper surface of the lifting platform 62 under the portion for fixing the bolt 66, and a screw hole for fixing the bolt (shown). ) Is formed. Due to the presence of the interposition material 67, the overhanging portion 65b of the mounting plate 65 floats without touching the upper surface of the elevating pedestal 62, unlike the portion where the interposition material 67 is located.

Further, a plurality of screw holes 65c are formed on the circumference of the mounting plate 65 having a diameter larger than the curve of the inner circumference of the overhanging portion 65b, including the positions on both sides of the portion to be fixed by the bolt 66.

As described above, the inner diameter of the overhanging portion 65b of the mounting plate 65 is slightly larger than the diameter of the outer peripheral surface of the outer heat insulating container 14, so that the elevating stand 62 is moved up and down with the outer heat insulating container 14 placed. It is possible to move up and down a part of the outer heat insulating container 14 without contacting the outer heat insulating container 14.

Therefore, on the upper end surface of the outer heat insulating container 14, that is, the upper surface of the upper end plate 14d, two removable flange plates 68 are provided as shown in FIG. The collar plate 68 is formed in the shape of a curved plate with a quarter arc, and the outer diameter of the collar plate 68 is larger than the diameter of the outer circumference of the outer heat insulating container 14 and the inner diameter of the overhanging portion 65b of the mounting plate 65. It is set large. The flange plate 68 is provided with a plurality of through holes 68a for bolting to the upper end plate 14d in an arc shape. In FIG. 6, 68b is a notch that prevents interference with the bolt 66 fixing the mounting plate 65.

FIG. 7 is a plan view of the outer heat insulating container 14 to which the flange plate 68 is fixed, which is housed inside the elevating stand 62, that is, in the windows 62b on both the upper and lower sides. As shown in this figure, when the collar plate 68 of the outer heat insulating container 14 is positioned above the mounting plate 65 of the lifting platform 62, the collar plate 68 overhangs the mounting plate 65 when the lifting platform 62 is raised. The outer heat insulating container 14 can be raised by being caught in the inner peripheral portion of the portion 65b.

In order to raise and lower the main body member 31 of the test container 16 by the elevating stand 62, at least one of the main body member 31 and the moving means 17 is provided with a connection mechanism that enables the main body member 31 and the moving means 17 to be connected and separated. As a part of the connection mechanism, a pair of auxiliary plates 69 as shown in FIG. 8 are detachably fixed on the mounting plate 65 of the elevating stand 62, and on the auxiliary plate 69. The locking member 71 as shown in FIG. 9 is fixed. On the other hand, the main body member 31 of the test container 16 is formed with a locked portion 72 to which the locking member 71 is locked.

Specifically, the auxiliary plate 69 is for reducing the opening of the central portion of the upper surface of the elevating stand 62 in accordance with the main body member 31 having a diameter smaller than that of the outer heat insulating container 14, and the two auxiliary plates. 69 have the same shape as each other.

The auxiliary plate 69 has a semicircular arcuate shape, the outer diameter is set to fit in the lifting platform 62, and the inner diameter is set to be slightly larger than the outer diameter of the large diameter portion 31c of the main body member 31. A plurality of through holes 69a for bolting to the mounting plate 65 are formed at positions corresponding to the screw holes 65c of the mounting plate 65 of the lifting platform 62 described above on the outer peripheral portion of the auxiliary plate 69. ing. Further, a notch 69b is formed at a portion corresponding to the bolt 66 fixing the mounting plate 65.

A set of screw holes 69c and loose holes 69d for fixing the locking member 71 are formed at a portion of the auxiliary plate 69 for fixing the locking member 71. As shown in FIG. 10, the parts for locking the locking member 71 are equidistant at positions rotated by a predetermined angle α from the vertical axis with the center P of the upper surface of the elevating stand 62 forming a square in a plan view as the center. There are four places. Three screw holes 69c for fixing the locking member 71 are arranged so as to draw a triangle, and one loose hole 69d described above is formed in a central portion surrounded by them.

As shown in FIG. 9, the locking member 71 includes a fixing plate 73 fixed to the upper surface of the auxiliary plate 69, a rectangular parallelepiped box-shaped upright support portion 74 extending over the fixing plate 73, and the inside of the upright support portion 74. It has a locking piece 75 that can be hung from. The fixing plate 73 has a through hole 73a corresponding to the screw hole 69c formed in the auxiliary plate 69, and an upright support portion 74 is formed in a portion surrounded by the three through holes 73a, and a flat surface is formed in the central portion thereof. A notch 73b forming a circular hole is formed. The position of the notch 73b is a position corresponding to the screw hole 69c of the auxiliary plate 69.

The upright support portion 74 has a horizontal top plate 74a on the upper end surface and an opening surface 74b on one of the four side surfaces. The upper end of the support shaft 76 is sandwiched and fixed to the top plate 74a by nuts 77. The above-mentioned locking piece 75 is held at a portion of the support shaft 76 located in the upright support portion 74. The locking piece 75 has a horizontal portion 78 and a vertical portion 79 and forms a right angle, and the vertical portion 79 is located outside the opening surface 74b of the standing support portion 74. The triangular portions on both sides of the locking piece 75 are reinforcing hanging walls 75a that maintain an angle between the horizontal portion 78 and the vertical portion 79. Further, in the center of the upper surface of the horizontal portion 78, a tubular portion 75b through which the support shaft 76 passes is formed inside.

A spring 81 for urging the locking piece 75 upward is inserted and held in a portion of the support shaft 76 below the horizontal portion 78. The fixed position of the support shaft 76 in a plan view is a position corresponding to the notch 73b of the fixing plate 73 and the loose hole 69d of the auxiliary plate 69.

A horizontally long rectangular locking plate portion 79a is formed below the vertical portion 79 of the locking piece 75 so as to project to both sides of the upper portion. The locking plate portion 79a has two insertion holes 79b for inserting bolts on both sides and two circular notch holes 79c between them.

As shown in FIG. 11, the locked portions 72 formed on the main body member 31 are formed at four locations at equal intervals on the outer peripheral surface of the large diameter portion 31c of the main body member 31. The locked portion 72 is made of a horizontally long rectangular plate material, has the same size as the locking plate portion 79a of the locking piece 75 in the locking member 71, and is fixed to the side surface of the large diameter portion 31c with a bolt 85. Has been done. A screw hole 72a is provided on the lateral side of the locked portion 72 with respect to the bolt 85. In FIG. 11, for convenience, one of the four locked portions 72 is drawn facing the front.

The bolt 85 for fixing the locked portion 72 is provided at a position corresponding to the notch hole 79c of the locking plate portion 79a described above, and the notch hole 79c prevents interference. Further, the screw hole 72a is formed at a position corresponding to the insertion hole 79b of the locking plate portion 79a.

The elevating position of the elevating stand 62 in the moving means 17 is set as follows.

Since it is necessary to attach / detach the test piece 12 to / from the test piece peripheral portion 15 in the test container 16, first, the test container 16 and the outer heat insulating container 14 having an exposed positional relationship and the test container 16 based on this positional relationship. This will be described in relation to the position where the main body member 31 is lowered.

FIG. 12 is a front view of a main part of the test container 16 and the outer heat insulating container 14 which are in an exposed positional relationship. That is, the height of the test container 16 is located above the outer heat insulating container 14 whose lower end is placed on the mounting table 52 with an appropriate interval in a state where the main body member 31 is connected to the lid member 32. Is supported by.

The lifting platform 62 that separates the main body member 31 of the test container 16 having such an exposed positional relationship from the lid member 32 can be moved to a position where the peripheral portion 15 of the test piece is exposed. The peripheral portion 15 of the test piece can be exposed if the test piece 12 can be attached and detached. That is, it is not necessary to lower the main body member 31 unnecessarily. Therefore, as shown in FIG. 13A, the descent may be such that a slight gap is formed between the lower end of the test piece peripheral portion 15 and the upper end position of the main body member 31. In FIG. 13, one of the four locked portions 72 is drawn facing the front for convenience.

Explaining the position where the main body member 31 is lowered for attaching / detaching the test piece 12 in relation to the outer heat insulating container 14, in other words, the height in the test apparatus 11, the main body member 31 is lowered to lower the test piece peripheral portion 15. The height H1 of the upper end position of the main body member 31 with respect to the bottom surface 14e which is the lower end of the outer heat insulating container 14 (see (a) of FIG. 13) is the height H2 of the outer heat insulating container 14 when the outer heat insulating container 14 is exposed. Is set lower than the height H4, which is the sum of the height H3 of the main body member 31 (see (b) in FIG. 13). That is, when the main body member 31 is lowered above the outer heat insulating container 14 placed on the mounting table 52 to expose the peripheral portion 15 of the test piece, the lower portion of the main body member 31 is the outer heat insulating container 14. It will fit inside. The range of the main body member 31 that fits inside the outer heat insulating container 14 is appropriately set in relation to the relationship between the elevating stand 62 and the upper end of the outer heat insulating container 14.

As shown in FIG. 3, the lower limit position of the moving means 17 is the flange plate 68 which is the upper end surface of the elevating stand 62, that is, the height of the mounting plate 65, which is the upper end of the outer heat insulating container 14 placed on the mounting table 52. It is a position slightly below. In other words, a slight gap S is formed between the mounting plate 65 of the elevating stand 62 at the lower limit position and the flange plate 68 of the outer heat insulating container 14 placed on the mounting base 52 located above this. Is set to.

As shown in FIGS. 1 and 4, the upper limit position of the moving means 17 is a position in which the outer heat insulating container 14 is surrounded. The position where the main body member 31 that has exposed the peripheral portion 15 of the test piece is raised and joined to the lid member 32 is slightly lower than the upper limit position of the moving means 17.

In the test apparatus 11 configured as described above, during the test in an extremely low temperature environment, the test container 16 is surrounded by the outer heat insulating container 14, and the refrigerant body is stored in the outer heat insulating container 14 and put into the test container 16. While the test is performed while suppressing heat and cooling the test container 16, during the test in a low temperature environment higher than the extremely low temperature, the test container 16 is surrounded by the outer heat insulating container 14 to suppress the heat input to the test container 16. A test method (mechanical property test method) is performed in which a tensile test is performed while performing the test, or the test is performed in a state where the outer heat insulating container 14 is separated from the test container 16 and the test container 16 is exposed.

The test in a cryogenic environment is performed as follows.

First, as shown in FIG. 14, with the outer heat insulating container 14 placed on the mounting table 52, the moving means 17 is driven to lower the main body member 31 of the test container 16. At this time, the auxiliary plate 69 and the locking member 71 are fixed on the elevating stand 62 of the moving means 17 to join the locked portion 72 of the main body member 31. In FIG. 14, one of the four locked portions 72 is drawn facing the front for convenience. The same is true in FIG.

After lowering the main body member 31 to expose the peripheral portion 15 of the test piece, the test piece 12 is attached, and the main body member 31 is attached to the lid member 32 by using the moving means 17 provided with the auxiliary plate 69 and the locking member 71. The housing portion 31a of the main body member 31 is closed as shown in FIG.

Next, the inside of the test container 16 is exhausted. A vacuum pump 44 is driven for exhaust (see FIG. 1). Subsequently, helium is supplied into the test container 16, a leak check is performed, and then helium gas is exhausted. Exhaust only needs to open the valve.

After that, hydrogen gas is supplied into the test container 16. Pressurize to the desired pressure by supplying hydrogen gas.

On the other hand, the vacuum heat insulating layer 14b of the outer heat insulating container 14 is evacuated, the pressure is lowered to a predetermined pressure, and then the outer heat insulating container 14 is raised.

That is, after removing the auxiliary plate 69 and the locking member 71, the lifting platform 62 is lowered to the lower limit position. Then, as shown in FIG. 3, the outer heat insulating container 14 is fitted inside the elevating stand 62, and the collar plate 68 is fixed to the upper surface of the outer heat insulating container 14. In this state, when the moving means 17 is driven to raise the elevating stand 62, the flange plate 68 is hooked on the mounting plate 65, and the outer heat insulating container 14 is raised.

As shown in FIG. 16, the outer heat insulating container 14 is placed in a surrounding position with respect to the test container 16, and then the moving means 17 is stopped.

Next, liquid nitrogen is supplied to the internal space 14a of the outer heat insulating container 14. The amount of liquid nitrogen is appropriately set in consideration of the cooling period. After filling with liquid nitrogen, the heat insulating lid 54 is used to close the opening on the upper surface of the outer heat insulating container 14. The cooling medium is not limited to liquid nitrogen, and may be a refrigerant such as liquid helium.

Subsequently, the temperature is controlled by the refrigerant body flowing from the refrigerant body flow path 16a, hydrogen gas is supplied to the test container 16, and hydrogen gas is added when the hydrogen gas pressure in the test container 16 drops due to cooling with liquid nitrogen. Supply. The airtightness test is performed after the temperature reaches a predetermined cooling temperature, the temperature stabilizes, and the pressure in the test container 16 reaches a predetermined pressure. The predetermined temperature is −150 ° C. or higher. The predetermined pressure is 100 Mpa or less.

After confirming that the airtight state is maintained, the low strain and low speed tensile test is started. The strain speed condition of this test is determined by the piston speed (mm / s) and is set by the servomotor speed. The low-strain, low-speed tensile test is performed until the control device 48 detects the breakage of the test piece 12, and the test is automatically completed.

After that, the hydrogen gas in the test container 16 is exhausted to reduce the pressure to purge the gas, the supply of liquid nitrogen for cooling from the refrigerant body flow path 16a is stopped, and the temperature returns to room temperature. After lowering the outer heat insulating container 14 to the exposed position, the test piece 12 is removed.

The test in a low temperature environment higher than the extremely low temperature is performed as follows.

When the test is performed only by surrounding the test container 16 with the outer heat insulating container 14, the supply of liquid nitrogen to the outer heat insulating container 14 in the above-described step is omitted.

When the test is performed without surrounding the test container 16 with the outer heat insulating container 14, the outer heat insulating container 14 is placed on the mounting table 52 without supplying liquid nitrogen to the outer heat insulating container 14. Do the test.

The evaluation of the test result is performed by the following method from the recorded data, the internal load cell output value (kN) and the displacement stroke output value (mm).
Stress (MPa) = Internal load cell output value / Desired cross-sectional area of test piece parallel part Strain rate (%) = (Displacement stroke / Initial length of test piece parallel part) x 100
The maximum test force of this test device is 20 kN.

As described above, the outer heat insulating container 14 can be selectively used to perform the test in a cryogenic environment or a low temperature environment having a higher temperature. That is, the outer heat insulating container 14 having a surrounding positional relationship forms a low temperature space in which the test container 16 is isolated from the outside world and the test container 16 is cooled from the outside by the refrigerant body flowing from the refrigerant body flow path 16a. That is, the test container 16 is cooled by the refrigerant body flowing from the refrigerant body flow path 16a while suppressing heat input to the test container 16 by the outer heat insulating container 14.

In the test in a low temperature environment having a temperature higher than the extremely low temperature, the test container 16 is cooled by the refrigerant body flowing from the refrigerant body flow path 16a while suppressing the heat input to the test container 16, and then the test container 16 is input. It is done without suppressing heat.

Therefore, the test can be performed in a desired low temperature environment including extremely low temperature.

Further, since the cryogenic environment in the test container 16 is created by the outer heat insulating container 14, the refrigerant body supplied into the outer heat insulating container 14, and the refrigerant body flowing from the refrigerant body flow path 16a, the test container 16 is as described above. High pressure containers can be used. Therefore, the test can be performed even in an extremely low temperature and high pressure environment.

In the test at an extremely low temperature, it is necessary to prepare the inside of the test container to a desired low temperature, but as a preparation, the test container 16 can be cooled only by moving the outer heat insulating container 14 and supplying the refrigerant body. Therefore, the work load is light. Further, after the outer heat insulating container 14 and the refrigerant body are set, cooling is possible even if the person is unmanned, so that the time for restraining the worker can be shortened. Moreover, since electric power is not required, it is possible to contribute to ensuring safety even when a flammable gas such as hydrogen gas is used as described above. Further, when the refrigerant body is liquid nitrogen, in addition to safety, the inspection device can be miniaturized and the operating cost can be reduced.

Further, the test container 16 and the outer heat insulating container 14 switch between the surrounding position and the exposed position. The outer heat insulating container 14 has a bottomed tubular shape having an opening 14c on the upper surface, and is moved up and down by the moving means 17. Therefore, switching between the two positions can be realized with a relatively simple configuration.

In this regard, the test container 16 has a main body member 31 and a lid member 32, and the lid member 32 is suspended and supported together with the peripheral portion 15 of the test piece, enabling connection and separation between the test container 16 and the moving means 17. Since the moving means 17 is configured to move the main body member 31 to a position where the peripheral portion 15 of the test piece is exposed, the movement of the main body member 31 for attaching or detaching the test piece 12 is also compared. It can be realized with a simple configuration.

Moreover, since the outer heat insulating container 14 and the main body member 31 can be moved up and down by one moving means 17, the configuration for moving can be simplified and the workability is good.

Regarding the moving means 17, in relation to the outer heat insulating container 14, as shown in FIG. 3, the flange plate 68 and the lifting stand of the outer heat insulating container 14 are before the outer heat insulating container 14 and the elevating pedestal 62 are locked. It is set so that the above-mentioned gap S is formed between the 62 mounting plate 65 and the mounting plate 65. Further, in relation to the main body member 31 of the test container 16, the locking member 71 is provided with a spring 81. Since these configurations are adopted, it is possible to alleviate the impact when the members come into contact with each other during ascent and descent.

Regarding the configuration of the moving means 17, in particular, the height of the upper end position of the main body member 31 with respect to the lower end of the outer heat insulating container 14 when the main body member 31 is lowered to expose the peripheral portion 15 of the test piece. Since the height is set lower than the height of the outer heat insulating container 14 plus the height of the main body member 31, the overall height of the test apparatus 11 can be kept low. Therefore, it is possible to prevent the test piece 12 from becoming difficult to perform work such as attaching and detaching.

Regarding the cooling function of the outer heat insulating container 14, since the outer heat insulating container 14 is a vacuum heat insulating container having the vacuum heat insulating layer 14b, high heat insulating property and heat insulating property can be obtained. Moreover, since the vacuum pump 51 is connected so as to evacuate during the test, the effect can be surely obtained.

Further, since the outer heat insulating container 14 is provided with an introduction path 53 for introducing the refrigerant body into the internal space 14a, a desired amount of the refrigerant body can be taken in as needed, and a desired cooling function can be obtained. Cooling can be done in the same way as when a refrigerator is attached.

Regarding the cooling function, although a space is formed between the upper end surface of the outer heat insulating container 14 and the test container 16, a removable heat insulating lid 54 is provided, so that the cooling function can be satisfactorily exhibited. ..

The above configuration is a configuration for carrying out the present invention, and the present invention is not limited to the above-mentioned configuration, and other configurations can be adopted.

For example, the mode for switching between the surrounding positional relationship and the exposed positional relationship may be one in which the test container 16 is moved instead of the outer heat insulating container 14, or both the outer heat insulating container 14 and the test container 16 may be moved. ..

The test may be performed not in a hydrogen gas environment but in another gas environment such as helium gas. Further, the test may be a test other than the tensile test. Further, the refrigerant body of the outer heat insulating container 14 and the refrigerant body flowing through the refrigerant body flow path 16a of the test container 16 do not have to be the same.

11 ... Low strain rate tensile test device 12 ... Test piece 14 ... Outer heat insulating container 14a ... Internal space 14b ... Vacuum heat insulating layer 15 ... Test piece peripheral part 16 ... Test container 16a ... Coolant body flow path 17 ... Moving means 31 ... Main body member 32 ... Lid member 53 ... Introduction pipe 54 ... Insulation lid 69 ... Auxiliary plate 71 ... Locking member 72 ... Locked part

Claims (9)

It is a mechanical property test device that stores the peripheral part of the test piece centering on the test piece in a test container and tests the test piece in an environment of room temperature to low temperature.
An outer heat insulating container having an internal space large enough to accommodate the test container and having heat insulating properties is provided.
By moving at least one of the outer heat insulating container or the test container, the surrounding positional relationship in which the outer heat insulating container surrounds the test container and the exposed position where the outer heat insulating container and the test container are separated to expose the test container. In relation to this, a mechanical property test apparatus provided with a moving means for relatively moving the outer heat insulating container and the test container. The outer heat insulating container has a bottomed tubular shape having an opening on the upper surface.
The mechanical property test apparatus according to claim 1, wherein the moving means moves the outer heat insulating container up and down. The test container has a main body member for accommodating a peripheral portion of the test piece and a lid member for closing the opening at the upper end of the main body member.
The lid member is suspended and supported together with the peripheral portion of the test piece.
At least one of the main body member and the moving means is provided with a connecting mechanism capable of connecting and separating the main body member and the moving means.
The mechanical property test apparatus according to claim 1 or 2, wherein the moving means is set so as to be movable to a position where the main body member is separated from the lid member and the peripheral portion of the test piece is exposed. The height of the upper end position of the main body member with respect to the lower end of the outer heat insulating container when the main body member is lowered to expose the peripheral portion of the test piece is the height of the outer heat insulating container. The mechanical property test apparatus according to claim 3, wherein the height is set lower than the height obtained by adding the heights of the members. The mechanical property test apparatus according to any one of claims 1 to 4, wherein the outer heat insulating container is a vacuum heat insulating container having a vacuum heat insulating layer. The mechanical property test apparatus according to any one of claims 1 to 5, wherein an introduction path for introducing a refrigerant body into the internal space is provided in the outer heat insulating container. The mechanical property test apparatus according to any one of claims 1 to 6, further comprising a removable heat insulating lid that closes the internal space of the outer heat insulating container. The mechanical property test apparatus according to any one of claims 1 to 7, wherein the test container is provided with a flow path for the medium to flow the medium, and the temperature inside the test container can be controlled. It is a mechanical property test method in which the peripheral part of the test piece centering on the test piece is stored in a test container and the test piece is tested in a low temperature environment.
The test container is suspended and supported, and is provided with an outer heat insulating container having a larger internal space than the test container and having heat insulating properties.
During the test in an extremely low temperature environment, the test container is surrounded by the outer heat insulating container and the refrigerant body is stored in the outer heat insulating container to suppress heat input to the test container and the refrigerant body from the refrigerant body flow path. While the test is performed while cooling the test container,
During the test in a low temperature environment higher than room temperature to extremely low temperature, the test container is surrounded by the outer heat insulating container, and a tensile test is performed while suppressing heat input to the test container and cooling with a refrigerant body. A mechanical property test method for performing a test in a state where the outer heat insulating container is separated from the test container and the test container is exposed.

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