Test temperature control system for cryogenic tension test, chamber for cryogenic tension test, and grip system

Abstract

The present invention relates to a test temperature control system for a cryogenic tension test, a chamber for a cryogenic tension test, and a grip system. The test temperature control system for a cryogenic tension test, of the present invention, can control the temperature of a chamber by controlling liquid helium injected into the chamber in which a specimen is mounted, thereby creating a cryogenic environment for a cryogenic tension test. The chamber for a cryogenic tension test and the grip system, of the present invention, can provide an ultra-low temperature chamber for a cryogenic tension test, and a grip enabling rapid specimen replacement.

Description

Test temperature control system for cryogenic tensile testing, chamber and grip system for cryogenic tensile testing

[0001] Embodiments of the present invention relate to a cryogenic tensile test temperature control system, a cryogenic tensile test chamber, and a grip system, and more particularly, to a cryogenic tensile test temperature control system capable of controlling a chamber temperature by controlling liquid helium injected into a chamber in which a specimen is mounted to create a cryogenic environment for a cryogenic tensile test, and a cryogenic tensile test chamber and grip system having a cryogenic chamber for a cryogenic tensile test and a grip capable of rapid specimen replacement.

[0002] The content described below is only described for the purpose of providing background information related to embodiments of the present invention, and the content described does not necessarily constitute prior art.

[0003] A tensile testing machine is a testing device used for tensile testing of materials.

[0004] Tensile testing can measure the tensile strength, yield point, elongation, and cross-sectional shrinkage of a material.

[0005] According to the conventional method, the cryogenic tensile tester mounts the specimen in a liquid nitrogen chamber and performs the tensile test in a cryogenic environment by spraying liquid nitrogen into the chamber.

[0006] However, as is well known, liquid nitrogen has a liquefaction temperature of 77 K, so it has the problem of not being able to be used for measuring the tensile deformation behavior of materials at extremely low temperatures below 77 K or at the level of 4 K.

[0007] Therefore, in order to conduct tensile tests on specimens at cryogenic temperatures of 4K, a differentiated technology capable of maintaining the chamber temperature at an ultra-low temperature is required.

[0008] In addition, in order to conduct tensile tests on specimens at extremely low temperatures, extremely low-temperature liquid helium (He) can be used, but completely new technological challenges need to be overcome, such as in terms of the supply of liquid helium.

[0009] Meanwhile, in order to conduct a tensile test of a specimen at an extremely low temperature, a technology different from the existing method is required in terms of the shape, structure, and insulation function of the chamber that can maintain the temperature of the chamber at an ultra-low temperature.

[0010] In addition, due to the characteristics of the cryogenic tensile tester, structural improvement of the specimen grip for loading and fastening the specimen into the chamber is necessary.

[0011] As a prior art related to the present invention, Korean Patent Publication No. 10-2022-0032430 discloses a cooling system including a chamber structure for cryogenic testing.

[0012] The purpose of the present invention is to provide a test temperature control system for cryogenic tensile testing, which can control the chamber temperature by controlling liquid helium injected into a chamber in which a specimen is mounted to create a cryogenic environment for cryogenic tensile testing.

[0013] The purpose of the present invention is to provide a cryogenic tensile test chamber and grip system that can improve the efficiency of cryogenic tensile tests.

[0014] The objectives of the present invention are not limited to those mentioned above. Other objectives and advantages of the present invention not mentioned above can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objectives and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0015] According to one aspect of the present invention, a test temperature control system for cryogenic tensile testing is provided, which can control the chamber temperature by controlling liquid helium injected into a chamber in which a specimen is mounted to create a cryogenic environment for cryogenic tensile testing.

[0016] According to one embodiment of the present invention, a test temperature control system for a cryogenic tensile test is a cryogenic tensile test temperature control system that controls a temperature required for a cryogenic tensile test by injecting liquid helium into a chamber that accommodates a specimen, the system comprising: a liquid helium storage unit that stores liquid helium; a liquid helium injection unit that is connected between the liquid helium storage unit and the chamber and injects liquid helium into the chamber; and a liquid helium injection control unit that injects gaseous helium into the liquid helium storage unit, controls the liquid helium injected into the chamber by controlling at least one of the injection amount and injection speed of the gaseous helium, and controls the temperature of the chamber.

[0017] According to one embodiment of the present invention, the liquid helium injection control unit includes a gas helium storage unit that stores gas helium; and a gas helium injection unit that is connected between the gas helium storage unit and the liquid helium storage unit and injects gas helium into the interior of the liquid helium storage unit.

[0018] According to one embodiment of the present invention, the gaseous helium storage unit may be a gaseous helium storage tank capable of storing a predetermined gaseous helium at a set pressure.

[0019] According to one embodiment of the present invention, the gaseous helium injection unit includes a gaseous helium transfer line having one end connected to the inside of the gaseous helium storage unit and the other end connected to the inside of the liquid helium storage unit, and transferring gaseous helium from the gaseous helium storage unit to the liquid helium storage unit; and a gaseous helium injection control valve connected to at least one of the gaseous helium transfer line and controlling at least one of the injection amount and injection speed of gaseous helium injected into the inside of the liquid helium storage unit.

[0020] Preferably, according to one embodiment of the present invention, the chamber further includes a temperature sensor for detecting the temperature of a specimen accommodated in the chamber, and a control unit for controlling the gaseous helium injection control valve to control at least one of the injection amount and injection speed of the gaseous helium based on the temperature information of the specimen detected by the temperature sensor. Accordingly, by receiving the temperature information of the specimen detected by the temperature sensor as feedback in real time and controlling at least one of the injection amount and injection speed of the gaseous helium, the liquid helium injected into the chamber can be more precisely controlled, thereby actively controlling the test temperature for the cryogenic tensile test.

[0021] According to one embodiment of the present invention, the gas helium injection control valve includes at least one of a proportional control valve, a solenoid valve, and an MFC (Mass Flow Controller).

[0022] According to one embodiment of the present invention, the liquid helium storage unit may be a liquid helium storage tank capable of storing a predetermined amount of liquid helium.

[0023] According to one embodiment of the present invention, the liquid helium injection unit includes a liquid helium transfer line having one end connected to the inside of the liquid helium storage unit and the other end connected to the chamber, and transferring liquid helium stored in the liquid helium storage unit to the chamber; a connecting pipe connected from the other end of the liquid helium transfer line to the lower end of the chamber, and formed to penetrate the lower end of the chamber and communicate with the interior of the chamber; and a liquid helium injection nozzle connected to the end of the connecting pipe and injecting liquid helium into the interior of the chamber.

[0024] A test temperature control system for a cryogenic tensile test according to one embodiment of the present invention may further include a heater heated to a set temperature to control the temperature of liquid helium flowing toward the liquid helium injection nozzle through the connecting pipe.

[0025] According to one embodiment of the present invention, the heater may be located outside the connecting pipe.

[0026] According to one embodiment of the present invention, the connecting pipe includes an inner pipe through which liquid helium flows toward the liquid helium injection nozzle; an outer pipe surrounding the inner pipe at a predetermined interval from the inner pipe; and an insulating material provided between the inner pipe and the outer pipe, and the heater may be embedded between the inner pipe and the outer pipe. In addition, a vacuum may be formed between the inner pipe and the outer pipe to improve insulating properties.

[0027] According to one embodiment of the present invention, the chamber has a chamber space for accommodating a specimen as a subject of a cryogenic tensile test, and can cool the specimen to a cryogenic temperature using liquid helium.

[0028] Preferably, a cryogenic tensile tester according to one embodiment of the present invention comprises: a main body having wheels that are installed vertically to have a predetermined height and can move forward, backward, left, and right for positional movement; a test drive unit located inside the main body; a load unit that protrudes a set length from the lower portion of the test drive unit and is connected to the upper portion of the grip unit and applies a load applied by the test drive unit to a specimen gripped by the grip unit. Preferably, the test drive unit comprises: a vertically movable body that moves vertically in the upper portion of the inner portion of the main body; a plurality of ball screws that are spaced left and right on the inner portion of the vertically movable body; a crosshead that is connected in a direction intersecting with the plurality of ball screws and moves vertically along the ball screws by a rotational force transmitted from a servo motor to move the load unit up and down; and a load sensor located between the crosshead and the load unit and detects a load applied to the load unit. The chamber is located at the inner lower portion of the main body, and the specimen is held by the grip portion connected to the lower portion of the load portion. The specimen held by the grip portion is accommodated inside the chamber, and when a cryogenic environment for a cryogenic tensile test is created, a tensile test can be performed.

[0029] According to another aspect of the present invention, a cryogenic tensile test chamber and grip system capable of improving the efficiency of cryogenic tensile tests are provided.

[0030] A chamber and grip system for cryogenic tensile testing according to one embodiment of the present invention comprises a chamber space for accommodating a specimen as a subject of a cryogenic tensile test, a chamber section for cooling the specimen to a cryogenic temperature using liquid nitrogen and liquid helium, and a grip section for gripping the ends of the specimen by inserting the specimen into the chamber space and allowing both ends of the specimen to be replaced in a sliding manner during a cryogenic tensile test.

[0031] In a cryogenic tensile test chamber and grip system according to one embodiment of the present invention, the chamber part includes a chamber body having a structure sealed from the outside so that the chamber space is located at the inner center and the liquid nitrogen and the liquid helium can be injected into the inside; and a vacuum insulation part provided inside the chamber body, wherein the chamber body includes an outer chamber; and an inner chamber located inside the outer chamber; and the vacuum insulation part can be located between the outer chamber and the inner chamber.

[0032] In a cryogenic tensile test chamber and grip system according to one embodiment of the present invention, the chamber section includes a first input section for supplying liquid nitrogen to the chamber space; a second input section for supplying liquid helium to the chamber space; a first output section for exhausting nitrogen gas used for cooling the specimen within the chamber space to the outside of the chamber body; and a second output section for exhausting helium gas used for cooling the specimen within the chamber space to the outside of the chamber body.

[0033] In one embodiment of the present invention, a cryogenic tensile test chamber and grip system further comprises: a first connection line having one end connected to the first input unit and the other end connected to the chamber space, and allowing the liquid nitrogen supplied to the first input unit to flow into the chamber space; a first nozzle provided at the other end of the first connection line and swirlingly injecting the liquid nitrogen into the chamber space; a second connection line having one end connected to the second input unit and the other end connected to the chamber space, and allowing the liquid helium supplied to the second input unit to flow into the chamber space; and a second nozzle provided at the other end of the second connection line and directly injecting the liquid helium onto the specimen accommodated in the chamber space.

[0034] In a chamber and grip system for cryogenic tensile testing according to one embodiment of the present invention, the chamber body has a cylindrical shape with an open center at the upper end and a closed center at the lower end, and the chamber body further includes a chamber stopper that opens and closes the center of the open upper end of the chamber body.

[0035] In a chamber and grip system for cryogenic tensile testing according to one embodiment of the present invention, each of the first input portion and the second input portion may be spaced apart from each other in the circumferential direction at a set interval on the circumferential surface of the chamber body, and each of the first output portion and the second output portion may be spaced apart from each other in the circumferential direction at a set interval outside the central region where the chamber lid is opened and closed at the upper end of the chamber body.

[0036] In a chamber and grip system for cryogenic tensile testing according to one embodiment of the present invention, the chamber portion further includes a vacuum port located outside a central region where the chamber lid is opened and closed at the upper end of the chamber body, and connected to the vacuum insulation portion to be opened and closed.

[0037] In a cryogenic tensile test chamber and grip system according to one embodiment of the present invention, the chamber section further includes an insulating material formed from the outside of the inner chamber toward the vacuum insulation section. For example, the insulating material may be installed by adhesively or non-adhesively wrapping an insulating material such as a multi-layer insulator (MLI) on the vacuum insulation section side of the inner chamber to minimize heat transfer by radiation within the vacuum insulation section.

[0038] In a cryogenic tensile test chamber and grip system according to one embodiment of the present invention, the chamber portion further includes a sensor for monitoring solidification of the liquid nitrogen. For example, the chamber portion may further include various sensors. As an example, the chamber portion further includes at least one liquid nitrogen specimen temperature sensor for detecting the temperature of the specimen due to liquid nitrogen, and at least one liquid helium specimen temperature sensor for detecting the temperature of the specimen due to liquid helium. In addition, the chamber portion further includes a liquid nitrogen liquefaction detection sensor for detecting liquefaction of the liquid nitrogen. The liquid nitrogen specimen temperature sensor and the liquid helium specimen temperature sensor may be positioned at one end of the grip portion, for example, at the lower end of the grip portion, and may be introduced into the chamber space. In addition, the liquid nitrogen liquefaction detection sensor may be positioned at the lower end of the chamber space.

[0039] In a chamber and grip system for cryogenic tensile testing according to one embodiment of the present invention, the grip portion includes a first replaceable grip for replaceably holding one end of the specimen; and a second replaceable grip for replaceably holding the other end of the specimen.

[0040] At this time, the first replaceable grip includes: a first fixing unit that fixes one end of the specimen; a first sliding fixing body that slides and replaceably connects the first fixing unit; and a first connecting ring that is connected to the first sliding fixing body.

[0041] In addition, the second replaceable grip includes a second fixing unit that fixes the other end of the specimen; a second sliding fixing body that slides and replaceably connects the second fixing unit; and a second connecting ring that is connected to the second sliding fixing body.

[0042] In a cryogenic tensile test chamber and grip system according to one embodiment of the present invention, the first fixing unit includes: a first cylindrical body into which one end of the specimen is inserted at the center; a first insertion body connected to the rear end of the first cylindrical body and slidably inserted into the first sliding fixing body; and a first circular groove formed between the first cylindrical body and the first insertion body.

[0043] In addition, the first sliding fixed body includes a first expansion body having a diameter larger than that of the first insertion body; a first sliding groove provided in the first expansion body and into which the first insertion body can be slidably inserted; and a first guide protrusion supported in the first circular groove and guiding the sliding of the first insertion body.

[0044] In a cryogenic tensile test chamber and grip system according to one embodiment of the present invention, the second fixing unit includes: a second cylindrical body into which the other end of the specimen is inserted at the center; a second insertion body connected to the rear end of the second cylindrical body and slidably inserted into the second sliding fixing body; and a second circular groove formed between the second cylindrical body and the second insertion body.

[0045] In addition, the second sliding fixed body includes a second expansion body having a diameter larger than that of the second insertion body; a second sliding groove provided in the second expansion body and into which the second insertion body can be slidably inserted; and a first guide protrusion supported in the second circular groove and guiding the sliding of the second insertion body.

[0046] According to the present invention, the chamber temperature can be controlled by controlling liquid helium injected into a chamber in which a specimen is mounted to create a cryogenic environment for a cryogenic tensile test.

[0047] Furthermore, according to the present invention, in order to inject liquid helium into a chamber, gaseous helium is injected into a liquid helium storage unit, and by controlling at least one of the injection amount and injection speed of gaseous helium, precise control of the liquid helium injected into the chamber can be achieved. Accordingly, the internal temperature of the chamber can be efficiently controlled through precise injection control of ultra-low temperature liquid helium.

[0048] In addition, according to the present invention, by placing a heater that heats liquid helium to a set temperature immediately before being injected into the chamber, a chamber temperature control function using a heater can be added, thereby further improving the test temperature control function for cryogenic tensile testing.

[0049] In addition, according to the present invention, by providing a chamber and a specimen grip applicable to a cryogenic tensile tester, the time required for a cryogenic tensile test can be significantly shortened, thereby improving the efficiency of the cryogenic tensile test.

[0050] Furthermore, according to the present invention, a nozzle system capable of independently injecting and exhausting different types of liquid refrigerants, i.e., liquid nitrogen and liquid helium, into and within the chamber can be provided. Accordingly, liquid nitrogen and liquid helium can be supplied and exhausted through different flow paths, enabling rapid and efficient cryogenic cooling of the chamber and specimen.

[0051] In addition, according to the present invention, a sensor capable of detecting solidification of liquid nitrogen is further included, thereby preventing the problem of liquid nitrogen being solidified by liquid helium.

[0052] Furthermore, according to the present invention, the chamber may be provided with two input and two output sections. Accordingly, liquid nitrogen and liquid helium at different temperatures are supplied into the chamber through independent channels, and after being used for cooling, they are exhausted through different channels, thereby enabling safe and accurate cryogenic tensile testing to be performed by utilizing different liquid refrigerants for cryogenic cooling of the chamber and specimen.

[0053] Furthermore, the present invention utilizes a specimen grip structure that allows rapid specimen replacement, enabling rapid loading and unloading of specimens for cryogenic tensile testing into the chamber. This reduces the time required for cryogenic tensile testing and enhances efficiency.

[0054] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0055] Figure 1 is a conceptual diagram of a test temperature control system for cryogenic tensile testing according to one embodiment of the present invention.

[0056] FIG. 2 is a conceptual diagram illustrating an operation of controlling gaseous helium injection by detecting a specimen temperature in a test temperature control system for a cryogenic tensile test according to one embodiment of the present invention.

[0057] Figure 3 is a conceptual diagram of a test temperature control system for cryogenic tensile testing according to another embodiment of the present invention.

[0058] Figure 4 is a conceptual diagram of a test temperature control system for cryogenic tensile testing according to another embodiment of the present invention.

[0059] FIG. 5 is a schematic drawing of a cryogenic tensile tester to which a cryogenic tensile test temperature control system according to an embodiment of the present invention can be applied.

[0060] FIGS. 6 and 7 are front and rear perspective views schematically illustrating a chamber portion in a cryogenic tensile test chamber and grip system according to one embodiment of the present invention.

[0061] FIG. 8 is a schematic drawing illustrating the internal structure of a chamber and grip system for cryogenic tensile testing according to one embodiment of the present invention.

[0062] FIG. 9 is a perspective view showing the joint structure of a grip portion in a chamber and grip system for cryogenic tensile testing according to one embodiment of the present invention.

[0063] Figure 10 is an exploded perspective view showing the exploded structure of a grip portion in a chamber and grip system for cryogenic tensile testing according to one embodiment of the present invention.

[0064] Figures 11, 12, and 13 are drawings showing the plate-shaped specimen grip structure.

[0065] The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily practice the technical idea of ​​the present invention. In describing the present invention, if it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0066] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0067] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0068] Hereinafter, the phrase "any configuration is placed on (or below)" a component or "on (or below)" a component may mean that any configuration is placed in contact with the upper surface (or lower surface) of said component, and that other configurations may be interposed between said component and any configuration placed on (or below) said component.

[0069] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component.

[0070] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "consisting of" or "comprising" should not necessarily be construed to include all of the components or steps described in the specification, and should be construed to mean that some of the components or steps may not be included, or that additional components or steps may be included.

[0071] Throughout the specification, when we refer to "A and / or B", this means A, B, or A and B, unless otherwise stated, and when we refer to "C through D", this means C or more and D or less, unless otherwise stated.

[0072] In the drawings, FIG. 1 is a conceptual diagram of a test temperature control system for a cryogenic tensile test according to an embodiment of the present invention, and FIG. 2 is a conceptual diagram illustrating an operation of detecting a specimen temperature and controlling gaseous helium injection in a cryogenic tensile test temperature control system according to an embodiment of the present invention. FIG. 3 is a conceptual diagram of a test temperature control system for a cryogenic tensile test according to another embodiment of the present invention, and FIG. 4 is a conceptual diagram of a test temperature control system for a cryogenic tensile test according to still another embodiment of the present invention. And FIG. 5 is a diagram briefly illustrating an example of a cryogenic tensile tester to which the cryogenic tensile test temperature control system according to an embodiment of the present invention is applicable.

[0073] Hereinafter, a cryogenic tensile tester to which a cryogenic tensile test temperature control system according to an embodiment of the present invention can be applied will be briefly described.

[0074] [Overall structure of the cryogenic tensile tester]

[0075] Referring to FIG. 5, in one embodiment of the present invention, a cryogenic tensile tester (1) includes a main body (10), a test driving unit (20), and a load unit (30).

[0076] The main body (10) refers to a frame structure that is installed vertically, i.e., up and down, to have a certain height.

[0077] Preferably, the main body (10) may have a structure that can freely move forward, backward, left, and right. For this purpose, wheels may be provided at the bottom of the main body (10).

[0078] The test drive unit (20) is a device that can move the specimen (S) into the chamber (50) to be mounted or moved upward to be unmounted, and can be located on the inside of the main body (10).

[0079] Preferably, the test drive unit (20) may be located on the inner upper side of the main body (10), and may be arranged to face the chamber (50) located on the inner lower side of the main body (10) vertically.

[0080] The test drive unit (20) can load the specimen (S) into the chamber (50) or separate it from the outside of the chamber (50) together with the load unit (30) and the grip unit (40) through the vertical movement of the crosshead (24). In addition, the specimen drive unit (50) can apply a load or displacement to the specimen (S) fixed by the grip unit (40) inside the chamber (50) through the vertical movement of the crosshead (24).

[0081] The load section (30) may have a structure that protrudes downward from the lower portion of the test drive section (20) by a set length.

[0082] Preferably, the load section (30) is connected vertically to the grip section (40) and can be connected vertically so as to form the same center.

[0083] In addition, when a set load is applied from the test drive unit (20), the load unit (30) can apply a load to the grip unit (40) to perform a tensile test of the specimen (S).

[0084] According to one embodiment of the present invention, the test drive unit (20) includes a vertical moving body (21), a ball screw (22), a servo motor (23), a crosshead (24), and a load sensor (25).

[0085] The vertically movable body (21) is a movable frame that is set to be able to move up and down from the inner upper part of the main body (10).

[0086] The ball screw (22) can be located inside the vertically movable body (21). A plurality of ball screws (22) can be arranged parallel to each other with equal spacing to the left and right of the center on the inside of the vertically movable body (21).

[0087] The crosshead (24) can be connected in a direction intersecting with a plurality of ball screws (22).

[0088] Preferably, the crosshead (24) is connected to each of the plurality of ball screws (22) and can move horizontally up and down along the length direction of the plurality of ball screws (22) by a finely set distance.

[0089] When the servo motor (23) operates and generates rotational force, the crosshead (24) connected to the ball screw (220) can move upward or downward a small distance. In addition, according to the movement of the crosshead (24), the load portion (30) connected to the lower portion of the crosshead (24) can move up and down. Accordingly, a set load or displacement can be applied to the specimen (S) fixed to the grip portion (40).

[0090] The load sensor (25) can be located between the crosshead (24) and the load portion (30), and the load sensor (25) can detect the load applied to the load portion (30).

[0091] Meanwhile, the chamber (50) may be located at the inner lower part of the main body (10), more specifically, lower than the test drive unit (20).

[0092] The grip portion (40) can be connected to the lower part of the load portion (30). The grip portion (40) can have a structure that holds both ends of the specimen (S).

[0093] The specimen (S) can be inserted into the chamber (50) while being fixed to the grip portion (40). Inside the chamber (50), the specimen (S) can undergo a cryogenic tensile test.

[0094] Hereinafter, a test temperature control system for cryogenic tensile testing according to embodiments of the present invention will be described in detail with reference to FIGS. 1 to 4.

[0095] [First embodiment of a test temperature control system for cryogenic tensile testing]

[0096] A test temperature control system (100) for a cryogenic tensile test according to the first embodiment of the present invention can control the temperature required for a cryogenic tensile test by injecting liquid helium into the interior of a chamber (50) that accommodates a specimen (S).

[0097] Referring to FIGS. 1 and 2, the chamber (50) has a chamber body (51) with a sealed interior (i.e., chamber space) (511). A specimen (S) secured by a grip portion (40) including first and second grips (41, 42) is introduced into the interior (i.e., chamber space) (511) of the chamber (51), and the grip portion (40) can be vertically connected to the load portion (30). With this configuration, during a cryogenic tensile test, the specimen (S) is introduced into the interior (i.e., chamber space) (511) of the chamber (50) while being secured to the grip portion (40), and an extremely low temperature environment can be created within the interior of the chamber (50). For this purpose, a cryogenic tensile test temperature control system (100) can be used.

[0098] Referring to FIGS. 1 and 2, a test temperature control system (100) for a cryogenic tensile test according to the first embodiment of the present invention includes a liquid helium storage unit (110), a liquid helium injection unit (120), and a liquid helium injection control unit (140).

[0099] The liquid helium storage unit (110) is a device that stores extremely low-temperature liquid helium.

[0100] Preferably, the liquid helium storage unit (110) may use a liquid helium storage tank capable of storing a set amount of liquid helium in an ultra-low temperature state.

[0101] The liquid helium injection unit (120) is connected between the liquid helium storage unit (110) and the chamber (50) and can inject liquid helium necessary for ultra-low temperature control of the chamber (50) into the interior of the chamber (50).

[0102] Preferably, the liquid helium injection unit (120) includes a liquid helium transfer line (121), a connecting pipe (123), and a liquid helium injection nozzle (124).

[0103] The liquid helium transfer line (121) refers to a pipeline whose one end (i.e., the inlet) is connected to the inside of the liquid helium storage unit (110) and whose other end (i.e., the outlet) is connected to the chamber (50). The liquid helium transfer line (121) transfers liquid helium stored in the liquid helium storage unit (110) to the chamber (50).

[0104] Preferably, a vacuum jacket (122) may be further included so as to surround the liquid helium transfer line (121). Accordingly, smooth and safe transfer of liquid helium in an extremely low temperature state can be enabled.

[0105] Preferably, one end (i.e., the inlet) of the liquid helium transfer line (121) may be positioned lower than the height of the other end (outlet) of the gas helium transfer line (1421). Accordingly, liquid helium can be smoothly injected into the chamber depending on the injection amount and injection speed of the gas helium.

[0106] The connecting pipe (123) refers to a pipe section that connects from the other end (i.e., the outlet) of the liquid helium transfer line (121) to the inner lower part of the chamber (50).

[0107] The connecting pipe (123) can be connected by penetrating the lower part of the chamber (50) in the thickness direction, and is designed to be connected to the inside of the chamber (50) so as to spray liquid helium.

[0108] The liquid helium injection nozzle (124) refers to a nozzle device connected to the end (i.e., outlet) of the above-mentioned connecting pipe (123).

[0109] The liquid helium injection nozzle (124) injects liquid helium transported through the liquid helium transport line (121) into the internal space of the chamber (50).

[0110] At this time, the amount of liquid helium injected into the chamber (50) can be precisely controlled according to the injection amount and injection speed of gaseous helium injected into the liquid helium storage unit (110), and the ultra-low temperature control of the chamber (50) can be precisely controlled.

[0111] The liquid helium injection control unit (140) can inject gaseous helium into the interior of the liquid helium storage unit (110).

[0112] Specifically, the liquid helium injection control unit (140) injects gaseous helium into the interior of the liquid helium storage unit (110), and at this time, the injection amount and injection speed of the gaseous helium injected into the interior of the liquid helium storage unit (110) can be controlled.

[0113] Accordingly, the liquid helium injection control unit (140) controls the injection amount of liquid helium injected into the interior of the chamber (50), thereby controlling the test temperature to secure an ultra-low temperature environment in the chamber (50) into which the specimen is placed during the ultra-low temperature tensile test.

[0114] Meanwhile, according to the first embodiment of the present invention, the liquid helium injection control unit (140) includes a gas helium storage unit (141) and a gas helium injection unit (142).

[0115] The gaseous helium storage unit (141) is a device that stores high-pressure gaseous helium.

[0116] Preferably, the gaseous helium storage unit (141) may use a gaseous helium storage tank capable of storing a predetermined gaseous helium at a set pressure.

[0117] The gaseous helium injection unit (142) is connected between the gaseous helium storage unit (141) and the liquid helium storage unit (110), and can inject gaseous helium into the interior of the liquid helium storage unit (110).

[0118] Preferably, the gas helium injection unit (142) includes a gas helium transfer line (1421) and a gas helium injection control valve (1422).

[0119] The gaseous helium transfer line (1421) is formed so that one end (i.e., the inlet) is connected to the inside of the gaseous helium storage unit (141) to enable the inflow of gaseous helium, and the other end (i.e., the outlet) is connected to the inside of the liquid helium storage unit (110) to enable the gaseous helium to be injected into the inside of the liquid helium storage unit (110).

[0120] Accordingly, the gaseous helium transfer line (1421) can transfer gaseous helium from the gaseous helium storage unit (141) to the liquid helium storage unit (110).

[0121] At least one gas helium injection control valve (1422) may be provided in the gas helium transfer line (1421).

[0122] The gas helium injection control valve (1422) may be a valve or a device having a function similar to a valve that controls at least one of the injection amount and injection speed of gas helium injected into the interior of the liquid helium storage unit (110).

[0123] Preferably, the gaseous helium injection control valve (1422) may use at least one of a proportional control valve, a solenoid valve, and an MFC (Mass Flow Controller) that controls at least one of the injection amount and injection speed of gaseous helium injected into the interior of the liquid helium storage unit (110).

[0124] However, the gas helium injection control valve (1422) in the present invention need not necessarily be limited to one of the above proportional control valve, solenoid valve, and MFC (Mass Flow Controller), and any device that is obvious to a person skilled in the art and has a similar function may be used without limitation.

[0125] Referring to FIG. 2, the test temperature control system (100) for cryogenic tensile testing according to the first embodiment of the present invention further includes a control unit (150).

[0126] The control unit (150) can control the operation of the gas helium injection control valve (1422).

[0127] Preferably, the temperature of the specimen (S) accommodated in the chamber (50) can be detected in real time (or at set time intervals) by the temperature sensor (70).

[0128] The control unit (150) can control at least one of the injection amount and injection speed of gaseous helium injected into the liquid helium storage unit (110) based on the temperature information of the specimen (S) detected by the temperature sensor (70).

[0129] In this way, according to the first embodiment of the present invention, the temperature information of the specimen is detected in real time (or at a set time interval) and fed back to the control unit (150).

[0130] The control unit (150) can actively control the internal temperature of the chamber (50) more precisely by controlling the injection amount and injection speed of gaseous helium based on the temperature information of the specimen.

[0131] [Second Embodiment of a Test Temperature Control System for Cryogenic Tensile Testing]

[0132] The test temperature control system (100) for a cryogenic tensile test according to the second embodiment of the present invention can control the temperature of liquid helium injected into the interior of the chamber (50) by heating it with a heater in addition to the first embodiment described above.

[0133] Referring to FIG. 3, the cryogenic tensile test temperature control system according to the second embodiment of the present invention may further include a heater (130) in addition to the cryogenic tensile test temperature control system (100) according to the first embodiment described above (see FIGS. 1 and 2).

[0134] The heater (130) is a heating device that is heated to a set temperature to control the temperature of liquid helium flowing toward the liquid helium injection nozzle (124) through the connecting pipe (123).

[0135] The heater (130) is located in a connecting pipe (123) connecting a liquid helium transfer line (121) and a liquid helium injection nozzle (124), and can control the temperature of liquid helium injected through the liquid helium injection nozzle (124) via the connecting pipe (123) to a set temperature.

[0136] Accordingly, in addition to the function of controlling the amount of liquid helium injected into the chamber (50) by controlling the injection amount and injection speed of gaseous helium in the liquid helium injection control unit (140), it can have the function of precisely controlling the temperature of the liquid helium finally injected into the chamber (50) through the liquid helium injection nozzle (124), so that the test temperature control function for the cryogenic tensile test can be improved.

[0137] Referring to FIG. 3, the heater (130) in the test temperature control system for a cryogenic tensile test according to the second embodiment of the present invention is positioned to surround the outside of the connecting pipe (123) and is configured to directly heat the connecting pipe (123) to a set temperature.

[0138] Meanwhile, in the case of the test temperature control system for the cryogenic tensile test according to the second embodiment of the present invention, it has a heating structure in which a single connecting pipe (123) and a heater (140) are directly attached to the outside of the connecting pipe (123) to heat it.

[0139] [Third Embodiment of a Test Temperature Control System for Cryogenic Tensile Testing]

[0140] The cryogenic tensile test temperature control system (100) according to the third embodiment of the present invention, unlike the second embodiment described above, has a double connection pipe (123) structure, and the heater (130) for heating the connection pipe (123) can be configured as a built-in structure. This allows for increased heating efficiency compared to the second embodiment described above.

[0141] Referring to FIG. 4, the cryogenic tensile test temperature control system according to the third embodiment of the present invention may further include a heater (130) in addition to the detailed configuration of the cryogenic tensile test temperature control system (100) (see FIGS. 1 and 2) as in the second embodiment described above.

[0142] The heater (130) is a heating device that is heated to a set temperature to control the temperature of liquid helium flowing toward the liquid helium injection nozzle (124) through the connecting pipe (123).

[0143] Referring to FIG. 4, the heater (130) according to the third embodiment of the present invention has a built-in structure.

[0144] Preferably, as shown in Fig. 4, the connecting pipe (123) includes an inner pipe (1231), an outer pipe (1232), and an insulating material (1233).

[0145] The internal pipe (1231) connects the liquid helium transfer line (121) and the liquid helium injection nozzle (124), and is a pipe through which liquid helium flows by penetrating the lower part of the chamber (50).

[0146] The external pipe (1232) refers to a pipe that surrounds the internal pipe (1231) from the outside while maintaining a predetermined distance from the internal pipe (1231).

[0147] Insulation (1233) refers to an insulating material filled between the inner pipe (1231) and the outer pipe (1232).

[0148] According to the third embodiment of the present invention, the built-in heater (130) can be built in the space between the inner pipe (1231) and the outer pipe (1232), that is, the inner space filled with insulation material (1233), and the inner space can be in a vacuum state to improve insulation efficiency.

[0149] This heater (130) is built into a connecting pipe (123) connecting a liquid helium transfer line (121) and a liquid helium injection nozzle (124), so that the temperature of liquid helium injected through the liquid helium injection nozzle (124) via the connecting pipe (123) can be adjusted to a set temperature.

[0150] Accordingly, in addition to the function of controlling the amount of liquid helium injected into the chamber (50) by controlling the injection amount and injection speed of gaseous helium in the liquid helium injection control unit (140), the function of precisely controlling the temperature of the liquid helium finally injected into the chamber (50) through the liquid helium injection nozzle (124) can be additionally provided, so that the test temperature control function for the cryogenic tensile test can be improved.

[0151] As described above, according to the configuration and operation of the present invention, the liquid helium injected into a chamber in which a specimen is mounted can be controlled to control the chamber temperature so as to create an ultra-low temperature environment for an ultra-low temperature tensile test. In addition, according to the present invention, in order to inject liquid helium into the chamber, gaseous helium is injected into a liquid helium storage unit, and by controlling at least one of the injection amount and the injection speed of the gaseous helium, precise control of the liquid helium injected into the chamber can be enabled. Accordingly, the internal temperature of the chamber can be efficiently controlled through precise injection control of the ultra-low temperature liquid helium. In addition, according to the present invention, by arranging a heater that heats the liquid helium to a set temperature immediately before it is injected into the chamber, a chamber temperature control function using the heater can be added, thereby further improving the test temperature control function for an ultra-low temperature tensile test.

[0152]

[0153] Meanwhile, referring to FIG. 5, the chamber part (50) may be located at the inner lower part of the main body part (10), more specifically, lower than the test drive part (20). The grip part (40) is connected to the lower part of the load part (30), and grips both ends of the specimen (S), which is the object of the cryogenic tensile test, so that they can be slidably attached and detached in a one-touch manner. The specimen (S), whose both ends are gripped by the grip part (40), may be moved downward together with the grip part (40) toward the inside of the chamber part (50), i.e., the inside of the chamber space, and may be installed therein. Thereafter, the specimen (S) may be cooled to a cryogenic temperature inside the chamber space using liquid nitrogen and liquid helium, and then the load part (30) may be moved up and down to perform the cryogenic tensile test.

[0154] Hereinafter, a cryogenic tensile test chamber and grip system according to an embodiment of the present invention will be described in detail with reference to the attached drawings.

[0155] [Detailed structure of the chamber and grip system for the cryogenic tensile tester]

[0156] In the drawings, FIGS. 6 and 7 are front and rear perspective views schematically illustrating a chamber portion in a cryogenic tensile test chamber and grip system according to one embodiment of the present invention, FIG. 8 is a drawing schematically illustrating the internal structure of a cryogenic tensile test chamber and grip system, FIG. 9 is a perspective view showing a coupling structure of a grip portion, and FIG. 10 is an exploded perspective view showing an exploded structure of a grip portion.

[0157] A chamber and grip system for cryogenic tensile testing according to an embodiment of the present invention includes a chamber portion (50) and a grip portion (40), and significantly reduces the cooling time of a specimen, thereby improving the efficiency of cryogenic tensile testing.

[0158] The chamber section (50) has a chamber space (511) that accommodates a specimen (S) that is the subject of a cryogenic tensile test.

[0159] The chamber section (50) cools the specimen (S) accommodated in the chamber space (511) to an extremely low temperature, and liquid nitrogen and liquid helium can be used.

[0160] The grip part (40) can be connected to both ends of the specimen (S) in a sliding manner so that they can be replaced.

[0161] The grip part (40) can hold both ends of the specimen (S) by placing the specimen (S) inside the chamber space (511) during a cryogenic tensile test.

[0162] [Chamber]

[0163] Hereinafter, the chamber portion (50) in the cryogenic tensile test chamber and grip system according to one embodiment of the present invention will be described in detail.

[0164] Referring to FIGS. 6 to 8, as illustrated, the chamber portion (50) includes a chamber body (51), a vacuum insulation portion (52), and an insulation material (53).

[0165] The chamber body (51) has a chamber space (511) located at the inner center, and may have a sealed structure with respect to the outside so that liquid nitrogen and liquid helium can be injected into the inside to cool the specimen (S) held in the grip portion (40) to an extremely low temperature and store it.

[0166] A vacuum insulation unit (52) can be provided inside the chamber body (51). The vacuum insulation unit (52) can secure a vacuum state space and insulate the extremely low temperature state of the chamber space (511) from the outside.

[0167] Specifically, the chamber body (51) has a structure including an outer chamber (51a) and an inner chamber (51b) located inside the outer chamber (51a). At this time, a vacuum insulation part (52) is located between the outer chamber (51a) and the inner chamber (51b).

[0168] Additionally, in order to secure vacuum in the vacuum insulation unit (52), the chamber body (51) may be further provided with a vacuum port (58) connected to the vacuum insulation unit (52).

[0169] The insulation (53) can be formed from the outside of the inner chamber (51b) toward the vacuum insulation part (52). That is, the insulation (53) can be installed from the inner chamber (51b) toward the vacuum insulation part (52). For example, the insulation (53) can be installed by wrapping an insulation material such as a multi-layer insulator (MLI) on the vacuum insulation part (52) side of the inner chamber (51b) in an adhesive or non-adhesive manner to minimize heat transfer by radiation within the vacuum insulation part (52).

[0170] Meanwhile, the chamber section (50) includes a first input section (54) for supplying liquid nitrogen, a second input section (55) for supplying liquid helium, a first output section (56) for exhausting nitrogen gas used for cryogenic cooling of the specimen, and a second output section (57) for exhausting helium gas used for cryogenic cooling of the specimen.

[0171] For example, the first input unit (54) is used to receive liquid nitrogen from the outside and supply the liquid nitrogen to the chamber unit (50), more specifically, to the sealed chamber space (511) inside the chamber body (51).

[0172] The second input unit (55) is used to receive liquid helium from the outside and supply the liquid helium to the chamber unit (50), more specifically, to the sealed chamber space (511) inside the chamber body (51).

[0173] The first output section (56) is used to exhaust nitrogen, i.e., nitrogen gas, used for cryogenic cooling of the specimen within the sealed chamber space (511) to the outside of the chamber body (51).

[0174] The second output section (57) is used to exhaust helium, i.e. helium gas used for cryogenic cooling of the specimen within the sealed chamber space (511), to the outside of the chamber body (51).

[0175] In this way, according to an embodiment of the present invention, the chamber body (51) constituting the chamber part (50) is provided with two input parts (54, 55) and two output parts (56, 57). In other words, the input parts through which liquid nitrogen and liquid helium are supplied into the interior of the chamber body (51) may be separately provided, and the output parts through which nitrogen and helium used for cooling the specimen are exhausted to the outside of the chamber body (51) may also be separately provided. Accordingly, by providing separate exhaust paths for nitrogen and helium having different temperatures, it is possible to prevent problems such as nitrogen to be exhausted being liquefied in advance.

[0176] In addition, in the chamber and grip system for cryogenic tensile testing according to one embodiment of the present invention, the chamber portion (50) further includes a first connecting line (541), a first nozzle (542), a second connecting line (551), and a second nozzle (552).

[0177] The first connecting line (541) provides a supply path for liquid nitrogen that supplies liquid nitrogen supplied to the first input section (54) to a predetermined chamber space (511) sealed inside the chamber body (51).

[0178] For example, one end of the first connecting line (541) may be connected to the first input portion (54), and the other end of the first connecting line (541) may be connected to the chamber space (511). However, it is not necessarily limited to the shape shown in FIGS. 6 and 7, and may be slightly changed to a different shape.

[0179] The first nozzle (542) may be provided at the other end of the first connecting line (541). The first nozzle (542) may use a swirling nozzle that injects liquid nitrogen into the interior of the chamber space (511) in a swirling manner.

[0180] The second connecting line (551) provides a supply path for liquid helium that supplies liquid helium supplied to the second input section (55) by flowing it to a predetermined chamber space (511) sealed inside the chamber body (51).

[0181] For example, one end of the second connecting line (551) may be connected to the second input section (55), and the other end of the second connecting line (551) may have a structure that is connected to the chamber space (511). However, it is not necessarily limited to the shape shown in FIGS. 6 and 7, and it may be slightly changed to a different shape.

[0182] A second nozzle (552) may be provided at the other end of the second connecting line (551). The second nozzle (552) may directly spray liquid helium onto a specimen (S) accommodated in the chamber space (511).

[0183] In other words, the second nozzle (552) can be positioned facing the specimen (S) that is fixed in a long position in the inner center of the chamber space (511) with both ends held by the grip portion (40), and the second nozzle (552) can use a direct injection nozzle that can directly inject liquid helium toward the specimen (S). This can enable cryogenic cooling of the specimen (S) more quickly and efficiently.

[0184] In addition, in the chamber and grip system for cryogenic tensile testing according to an embodiment of the present invention, the chamber body (51) may have a cylindrical shape in which the center of the upper part (512) is open and the lower part (513) is closed at the front (see FIGS. 6 and 7).

[0185] And the chamber part (50) further includes a chamber stopper (59). The chamber stopper (59) can be provided in a form that can be combined or separated from the chamber body (51) to open or close an open portion formed in the center of the upper part (512) of the chamber body (51).

[0186] Meanwhile, the first input unit (54) and the second input unit (55) can be formed at different locations and placed at a certain distance from each other, so that liquid nitrogen and liquid helium can be stably supplied at different locations.

[0187] For example, if the chamber body (51) has a cylindrical shape, the first input part (54) and the second input part (55) can be spaced apart from each other in the circumferential direction at a set interval on the cylindrical surface of the chamber body (51) (see FIGS. 6 and 7).

[0188] The first output section (56) and the second output section (57) can be formed at different locations and spaced apart from each other at a certain distance, thereby eliminating interference between the exhaust path of nitrogen exhausted to the outside and the exhaust path of helium exhausted.

[0189] For example, if the chamber body (51) has a cylindrical shape, the first output part (56) and the second output part (57) can be spaced apart from each other in the circumferential direction at a set interval outside the central open area where the chamber stopper (59) is opened and closed in the upper part of the chamber body (51). As a result, the gaseous nitrogen and helium used for cooling the specimen can be exhausted to the outside through independent paths, and the exhaust ports for the nitrogen and helium are formed at a set distance from each other, which has the advantage of securing convenience and stability in operation.

[0190] Meanwhile, the vacuum port (58) may be located on one side of the upper part (512) of the chamber body (51) outside the central open area where the chamber stopper (59) is opened and closed in the cylindrical chamber body (51), and may be connected to the vacuum insulation part (52) inside the chamber body (51).

[0191] Meanwhile, the chamber section (50) of the cryogenic tensile test chamber and grip system according to one embodiment of the present invention may further include a sensor (60) for detecting solidification of liquid nitrogen. Accordingly, solidification of liquid nitrogen can be detected in real time during the cryogenic cooling process of a specimen using liquid nitrogen and liquid helium, thereby enabling an operator to monitor for problems occurring in the flow and cooling function of the liquid nitrogen.

[0192] In addition, the chamber part (50) may further include a liquid nitrogen specimen temperature sensor that detects the temperature of the specimen due to liquid nitrogen and a liquid helium specimen temperature sensor that detects the temperature of the specimen due to liquid helium, although not shown separately. In addition, the chamber part (50) may further include a liquid nitrogen liquefaction detection sensor that detects liquefaction of liquid nitrogen, although not shown separately. The liquid nitrogen specimen temperature sensor (not shown) and the liquid helium specimen temperature sensor (not shown) may be positioned at one end of the grip part (40), for example, at the bottom of the grip part (40), and may be introduced into the chamber space (511). In addition, the liquid nitrogen liquefaction detection sensor may be positioned at the bottom of the chamber space.

[0193] Meanwhile, referring to FIG. 8, the arrangement structure of the grip part (40) that holds and fixes both ends of the specimen (S) inside the chamber part (50) that constitutes the chamber and grip system for cryogenic tensile testing, and the connection appearance of the load part (30) connected to the upper part of the grip part (40) are shown.

[0194] [Grip]

[0195] Hereinafter, the grip portion (40) in the cryogenic tensile test chamber and grip system according to one embodiment of the present invention will be described in detail.

[0196] Referring to FIGS. 9 and 10, as illustrated, the grip portion (40) is configured to grip both ends of the specimen (S) by inserting the specimen (S) into the chamber space (511) (see FIGS. 6 and 7) during a cryogenic tensile test.

[0197] Accordingly, a set tensile load can be applied to a specimen (S) with both ends gripped by the grip portion (40), making it possible to perform a cryogenic tensile test.

[0198] In addition, the grip portion (40) has a structure that can be quickly slidably connected and released from both ends of the specimen (S) to improve the convenience of replacing the specimen (S) and shorten the time for replacing and mounting the specimen (S).

[0199] Figure 9 shows a state in which the grip part (40) is combined with the specimen (S), and Figure 10 shows a state in which the grip part (40) is separated from the specimen (S).

[0200] Referring to FIGS. 9 and 10, the illustrated grip portion (40) includes a first replaceable grip (41) and a second replaceable grip (42).

[0201] The first replaceable grip (41) may have a shape that allows one end of the specimen (S) to be replaced in a sliding manner.

[0202] The second replaceable grip (42) may have a shape that allows the other end of the specimen (S) to be replaced in a sliding manner.

[0203] Specifically, the first replaceable grip (41) includes a first fixing unit (413), a first sliding fixing body (411), and a first connecting ring (412).

[0204] For example, the first fixed unit (413) inserts and fixes one end of the specimen (S).

[0205] The first sliding fixed body (411) can be replaced and connected by sliding the first fixed unit (413).

[0206] And the first connecting ring (412) refers to a ring-shaped member that is connected to the first sliding fixed body (411).

[0207] Specifically, the second replaceable grip (42) includes a second fixed unit (423), a second sliding fixed body (421), and a second connecting ring (422).

[0208] For example, the second fixed unit (423) inserts and fixes the other end of the specimen (S).

[0209] The second sliding fixed body (421) can be replaced and connected by sliding the second fixed unit (423).

[0210] And the second connecting ring (422) refers to a ring-shaped member that is connected to the second sliding fixed body (421).

[0211] More specifically, the first fixed unit (413) includes a first cylindrical body (4131), a first insertion body (4133), and a first circular groove (4132) (see FIG. 10).

[0212] Referring to Fig. 10, the first cylindrical body (4131) is a cylindrical body having an insertion groove into which one end of a specimen (S) is inserted. One end of the specimen (S) can be inserted and fixed at the center of the first cylindrical body (4131).

[0213] In addition, the first insertion body (4133) can be connected to the rear end of the first cylindrical body (4131), and can be connected and separated from the first sliding fixed body (411) in a sliding manner with one touch.

[0214] In addition, the first circular groove (4132) is a circular belt-shaped groove formed between the first cylindrical body (4131) and the first insertion body (4133). The first circular groove (4132) is used as a groove into which the first guide protrusion (4113) of the first sliding fixed body (411) is inserted.

[0215] To be more specific, the first sliding fixed body (411) includes a first expansion body (4111), a first sliding groove (4112), and a first guide protrusion (4113) (see FIG. 10).

[0216] Referring to FIG. 10, the first expansion body (4111) has a cylindrical shape with a diameter that is larger than that of the first insertion body (4133).

[0217] Additionally, a first sliding groove (4112) is provided on the inside of the first expansion body (4111). The first sliding groove (4112) is used as a groove into which the first insertion body (4133) is inserted in a sliding manner.

[0218] Additionally, the first guide protrusion (4113) is supported on the first circular groove (4132) and guides the sliding engagement and release of the first insert body (4133).

[0219] More specifically, the second fixed unit (423) includes a second cylindrical body (4231), a second insertion body (4233), and a second circular groove (4232) (see FIG. 10).

[0220] Referring to Fig. 10, the second cylindrical body (4231) is a cylindrical body having an insertion groove into which the other end of the specimen (S) is inserted. The other end of the specimen (S) can be inserted and fixed at the center of the second cylindrical body (4231).

[0221] In addition, the second insertion body (4233) can be connected to the rear end of the second cylindrical body (4231), and can be connected and separated from the second sliding fixed body (421) in a sliding manner with one touch.

[0222] In addition, the second circular groove (4232) is a circular belt-shaped groove formed between the second cylindrical body (4231) and the second insertion body (4233). The second circular groove (4232) is used as a groove into which the second guide protrusion (4213) of the second sliding fixed body (421) is inserted.

[0223] To be more specific, the second sliding fixed body (421) includes a second expansion body (4211), a second sliding groove (4212), and a second guide protrusion (4213) (see FIG. 10).

[0224] Referring to FIG. 10, the second expansion body (4211) has a cylindrical shape with a diameter that is larger than that of the second insertion body (4233).

[0225] Additionally, a second sliding groove (4212) is provided on the inside of the second expansion body (4211). The second sliding groove (4212) is used as a groove into which the second insertion body (423) is inserted in a sliding manner.

[0226] Additionally, the second guide protrusion (4213) is supported by the second circular groove (4232) and guides the sliding engagement and release of the second insert body (4233).

[0227] By configuring in this manner, the specimen (S), which is the subject of the cryogenic tensile test, can be quickly mounted and removed from the grip portion (40). In addition, if necessary, it can be quickly replaced with another specimen and mounted.

[0228] In this way, according to an embodiment of the present invention, the prepared specimen (S) can be easily and conveniently replaced and mounted quickly and accurately without using a separate fastening member such as a bolt, thereby shortening the time required for a cryogenic tensile test.

[0229] Meanwhile, referring to FIGS. 9 and 10, the grip portion (40) and the specimen (S) shown disclose a structure suitable for a rod-shaped specimen, but are not limited thereto, and may include a structure capable of replacing and mounting a plate-shaped specimen in a sliding manner.

[0230] Figures 11, 12, and 13 are drawings showing the plate-shaped specimen grip structure.

[0231] As illustrated, for example, a grip (45) for a plate-shaped specimen may include a cylindrical body (451), a fixing body (453) for fixing the plate-shaped specimen (S), and a circular groove (452).

[0232] Referring to FIGS. 12 and 13, the fixed body (453) for fixing the plate-shaped specimen (S) includes a first fixed body (4531) and a second fixed body (4532) that is fastened to face the first fixed body (4531).

[0233] The inner side of the fixed body (453) is provided with a specimen insertion groove (4533) into which an end of a plate-shaped specimen (S), for example, an end of a square plate-shaped specimen (S), is inserted to prevent separation.

[0234] The plate-shaped specimen (S) can be inserted into the specimen insertion groove (4533) and then fixed by fastening between the first fixing body (4531) and the second fixing body (4532). A plurality of fastening holes (4534) capable of bolt fastening may be further provided for fastening between the first fastening body (4531) and the second fixing body (4532).

[0235] As described above, according to the configuration and operation of the present invention, by providing a chamber and a specimen grip applicable to a cryogenic tensile tester, the time required for a cryogenic tensile test can be significantly shortened, thereby improving the efficiency of the cryogenic tensile test. In addition, according to the present invention, a nozzle system capable of spraying and exhausting different types of liquid refrigerants, i.e., liquid nitrogen and liquid helium, into and into the chamber can be independently provided. Accordingly, liquid nitrogen and liquid helium can be supplied and exhausted through different flow paths, thereby enabling rapid and efficient cryogenic cooling of the chamber and specimen. In addition, according to the present invention, a sensor capable of detecting solidification of liquid nitrogen can be further included, thereby preventing in advance the problem of liquid nitrogen solidifying by liquid helium. In addition, according to the present invention, two input units and two output units can be provided on the chamber. Accordingly, liquid nitrogen and liquid helium at different temperatures are supplied into the chamber through independent channels, and after being used for cooling, they are exhausted through different channels, thereby enabling safe and accurate cryogenic tensile testing to be performed by utilizing different liquid refrigerants for cryogenic cooling of the chamber and specimen. In addition, according to the present invention, a specimen grip structure that enables rapid specimen replacement is utilized, enabling rapid loading and unloading of specimens for cryogenic tensile testing into the chamber. Accordingly, the time required for cryogenic tensile testing can be shortened and efficiency can be increased.

[0236] Although the present invention has been described with reference to the drawings exemplified above, it is to be understood that the present invention is not limited to the embodiments and drawings disclosed herein, and that various modifications may be made by those skilled in the art within the scope of the technical idea of ​​the present invention. Furthermore, even if the operational effects according to the configuration of the present invention have not been explicitly described while describing the embodiments of the present invention, it is natural that the effects predictable by the corresponding configuration should also be acknowledged.

Claims

1. A test temperature control system for cryogenic tensile testing that controls the temperature required for cryogenic tensile testing by injecting liquid helium into the chamber that accommodates the specimen. A liquid helium storage unit for storing liquid helium; A liquid helium injection unit connected between the liquid helium storage unit and the chamber and injecting liquid helium into the chamber; A liquid helium injection control unit that injects gaseous helium into the liquid helium storage compartment, controls the liquid helium injected into the chamber by controlling at least one of the injection amount and injection speed of the gaseous helium, and controls the temperature of the chamber; Test temperature control system for cryogenic tensile testing including:

2. In paragraph 1, The above liquid helium injection control unit, A gaseous helium storage unit for storing gaseous helium; and A gaseous helium injection unit connected between the gaseous helium storage unit and the liquid helium storage unit, and injecting gaseous helium into the interior of the liquid helium storage unit; A test temperature control system for cryogenic tensile testing including:

3. In paragraph 2, The above gaseous helium storage unit is, A test temperature control system for cryogenic tensile testing, which is a gaseous helium storage tank capable of storing a predetermined amount of gaseous helium at a set pressure.

4. In paragraph 2, The above gaseous helium injection unit, A gaseous helium transfer line, one end of which is connected to the inside of the gaseous helium storage unit and the other end of which is connected to the inside of the liquid helium storage unit, transferring gaseous helium from the gaseous helium storage unit to the liquid helium storage unit; and A gaseous helium injection control valve connected to at least one of the gaseous helium transfer lines and controlling at least one of the injection amount and injection speed of gaseous helium injected into the interior of the liquid helium storage unit; A test temperature control system for cryogenic tensile testing including:

5. In paragraph 4, The above gas helium injection control valve is, A test temperature control system for cryogenic tensile testing comprising at least one of a proportional control valve, a solenoid valve, and a mass flow controller (MFC).

6. In paragraph 1, The above liquid helium storage unit is, A test temperature control system for cryogenic tensile testing, which is a liquid helium storage tank capable of storing a certain amount of liquid helium.

7. In paragraph 1, The above liquid helium injection unit, A liquid helium transfer line having one end connected to the inside of the liquid helium storage unit and the other end connected to the chamber, and transferring liquid helium stored in the liquid helium storage unit to the chamber; A connecting pipe that is connected from the other end of the liquid helium transfer line to the lower end of the chamber, and is formed by penetrating the lower end of the chamber and communicating with the interior of the chamber; and A liquid helium injection nozzle connected to the end of the above connecting pipe and injecting liquid helium into the interior of the chamber; A test temperature control system for cryogenic tensile testing including:

8. In paragraph 7, A heater heated to a set temperature to control the temperature of liquid helium flowing toward the liquid helium injection nozzle through the above connecting pipe; A test temperature control system for cryogenic tensile testing, further comprising:

9. In paragraph 8, The above heater, A test temperature control system for cryogenic tensile testing located outside the above connecting pipe.

10. In paragraph 8, The above connecting pipe is, An internal pipe through which liquid helium flows toward the liquid helium injection nozzle; An external pipe that surrounds the internal pipe at a predetermined distance from the internal pipe; and Including an insulating material provided between the inner pipe and the outer pipe; The above heater, A test temperature control system for cryogenic tensile testing built between the inner pipe and the outer pipe.

11. A chamber space for accommodating a specimen as a subject of a cryogenic tensile test, and a chamber section for cooling the specimen to a cryogenic temperature using liquid nitrogen and liquid helium; and A grip part that allows the two ends of the above specimen to be replaced in a sliding manner and that holds the two ends of the specimen by inserting the specimen into the chamber space during a cryogenic tensile test; A chamber and grip system for cryogenic tensile testing, including:

12. In paragraph 11, The above chamber part, A chamber body having a sealed structure with the outside so that the chamber space is located in the inner center and the internal injection of the liquid nitrogen and the liquid helium is possible; and including a vacuum insulation part provided inside the chamber body; The chamber body includes an outer chamber; and an inner chamber located inside the outer chamber; The above vacuum insulation unit is a cryogenic tensile test chamber and grip system located between the outer chamber and the inner chamber.

13. In paragraph 12, The above chamber part, A first input section for supplying the liquid nitrogen into the chamber space; A second input section for supplying the liquid helium into the chamber space; A first output section for exhausting nitrogen gas used for cooling the specimen within the chamber space to the outside of the chamber body; and A second output section for exhausting helium gas used for cooling the specimen within the chamber space to the outside of the chamber body; A chamber and grip system for cryogenic tensile testing, including:

14. In paragraph 13, The above chamber body has a cylindrical shape with the center of the upper part open and the lower part completely sealed. The above chamber part, A chamber stopper that opens and closes the center of the open upper part of the chamber body; A chamber and grip system for cryogenic tensile testing further comprising:

15. In paragraph 14, Each of the first input unit and the second input unit, They are spaced apart from each other in the circumferential direction on the circumferential surface of the chamber body, Each of the first output and the second output section, A cryogenic tensile test chamber and grip system in which the chamber lids are spaced apart from each other in the circumferential direction at a set interval from the central region where the chamber lids are opened and closed at the upper part of the chamber body.

16. In paragraph 14, The above chamber part, A vacuum port located outside the central area where the chamber cap is opened and closed at the upper end of the chamber body, and connected to the vacuum insulation unit to be opened and closed; A chamber and grip system for cryogenic tensile testing further comprising:

17. In paragraph 12, The above chamber part, Insulating material formed on the outside of the inner chamber toward the vacuum insulation section; A chamber and grip system for cryogenic tensile testing further comprising:

18. In paragraph 11, The above chamber part, A sensor for monitoring the solidification of the liquid nitrogen; A chamber and grip system for cryogenic tensile testing further comprising:

19. In paragraph 11, The above grip part, A first replaceable grip for slidingly holding one end of the above specimen; and A second replaceable grip for slidingly holding the other end of the above specimen; A chamber and grip system for cryogenic tensile testing, including:

20. In paragraph 19, The above first replaceable grip is, A first fixing unit for fixing one end of the above-mentioned specimen; A first sliding fixed body that slides and replaceably connects the first fixed unit; and A first connecting ring coupled to the first sliding fixed body; The above second replaceable grip is, A second fixing unit that fixes the other end of the above-mentioned psalm; A second sliding fixed body that slides and replaceably connects the second fixed unit; and A second connecting ring coupled to the second sliding fixed body; A chamber and grip system for cryogenic tensile testing, including:

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