Characteristic Test Equipment

Abstract

To provide a compact and low-cost testing device that can simultaneously test such material characteristics as fatigue characteristics of a plurality of test pieces under an extremely low-temperature hydrogen environment.SOLUTION: A compact material characteristic testing device is realized which can test such material characteristics as fatigue characteristics in a wide temperature range from an extremely low temperature to a high temperature, by storing containers 3a, 3b...in a constant temperature tank 4, the containers being divided in active spaces 6a, 6b...and passive spaces 10a, 10b...by flat testing pieces 2a, 2b...of the container, and by supplying a (hydrogen) gas from fluid supply means 13 to the active spaces 6a, 6b..while changing a pressure by an active pressure changing valve 19 and repeatedly applying a changing bending load to the flat testing pieces 2a, 2b....SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a characteristic testing apparatus capable of simultaneously testing the material characteristics of a plurality of test pieces in a predetermined environment such as a hydrogen atmosphere over a wide temperature range. [Background technology]

[0002] In recent years, fuel cells, which are used as driving power sources for automobiles, drones, motorcycles, bicycles, and other vehicles, are power generation systems that generate electricity through an electrochemical reaction between hydrogen (H2) contained in the fuel and oxygen (O2) in the air. The hydrogen fuel is often stored in a tank in a gaseous state, compressed to high pressure. When automobiles (FCVs: Fuel Cell Vehicles) or drones (FCDs: Fuel Cell Drones) equipped with such fuel cell systems travel or fly at high speeds, especially in winter, the hydrogen gas undergoes rapid adiabatic expansion, which can cause the temperature of the hydrogen tank to drop below freezing. As a result, the constituent materials of the hydrogen tank are subjected to load fluctuations at extremely low temperatures, which could lead to their destruction.

[0003] Patent Document 1 below discloses a characteristic testing device for simulating real-world testing of hydrogen tank components. This characteristic testing device can perform fatigue testing by placing a flat test piece in a container and repeatedly applying a bending load to the test piece in a hydrogen atmosphere. This characteristic testing device has a flow path in the thickness of the container that contains hydrogen, and attempts to control the temperature inside the container by flowing a heat transfer medium through the flow path.

[0004] On the other hand, Patent Document 2 below discloses a gas-permeable membrane-using device in which a gas-permeable membrane unit consisting of a supply chamber and a permeation chamber separated by a gas-permeable membrane is housed in a thermostatic chamber. This gas-permeable membrane-using device aims to provide a device that can function safely by suppressing the release of large amounts of gas when the membrane collapses. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2016-195436 [Patent Document 2] Patent Publication No. 2004-122040 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the conventional characteristic testing device disclosed in Patent Document 1 attempts to control the temperature inside the container by providing a flow path in the thickness of the container containing hydrogen and flowing a heat medium through the flow path, which makes it difficult to maintain a uniform temperature throughout the container.It is also difficult to create a large temperature difference between the container and its environment, making it difficult to set the container temperature to a predetermined value over a wide temperature range from extremely low to high temperatures.

[0007] Furthermore, both the characteristic testing device of Patent Document 1 and the device using a gas-permeable membrane of Patent Document 2 are based on the premise that one piece of data is obtained under one temperature condition for each test piece or gas-permeable membrane, and are not configured to obtain multiple pieces of data simultaneously.

[0008] The present invention was made in consideration of these problems, and its main object is to provide a characteristic testing device that can acquire as much data as possible by conducting as few tests as possible with as few characteristic testing devices as possible, and that can build a highly reliable database including the average values ​​and variances of material properties. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, the characteristic test device according to claim 1 of the present invention is a characteristic test device for evaluating the characteristics or durability of a test piece in a fluid atmosphere, and is characterized by comprising at least one container for storing the test piece, a fluid supply means for supplying a fluid to an operating space between the container and the stored test piece, a fluid pressure adjustment means for adjusting the pressure of the fluid supplied to the operating space, and a thermostatic bath for storing the container.

[0010] Furthermore, the characteristic test device described in claim 2 of the present invention is characterized in that, in the characteristic test device described in claim 1, it is provided with a plurality of fluid supply means for supplying fluid to the working space between the container and the stored test piece, and a plurality of working pressure adjustment means for adjusting the pressure of the fluid supplied to the working space.

[0011] Furthermore, the characteristic test device according to claim 3 of the present invention is the characteristic test device according to claim 1 and claim 2, characterized in that the temperature of the container can be set below freezing. [Effects of the Invention]

[0012] According to the characteristic testing device of the present invention, by controlling the fluid pressure, a bending load can be applied to a flat test piece stored in a container, thereby achieving a compact structure and reducing fluid leakage outside the device.

[0013] According to the characteristic testing device of the present invention, the container is placed in a constant temperature bath, which allows the temperature of the entire container to be kept roughly uniform, and also makes it possible to set a large temperature difference between the container environment and the container, thereby achieving the effect of being able to set the temperature of the container to a predetermined temperature within a wide temperature range from extremely low to high temperatures.

[0014] The characteristic testing device according to the present invention has the advantage that at least one container, preferably multiple containers, can be stored in a thermostatic chamber, and the material properties of at least one test piece, preferably multiple test pieces, can be tested simultaneously.

[0015] Furthermore, in addition to the effect of the characteristic testing device of claim 1, the characteristic testing device of the present invention has the effect of continuously or intermittently applying a bending load to the test piece by the pressure difference between the operating space and the passive space by continuously or intermittently varying the internal pressure of the operating space.

[0016] In addition to the effects of the characteristic testing device according to the present invention, the temperature of the thermostatic chamber can be varied to change the temperature of the container and / or test piece within a predetermined temperature range, thereby enabling a temperature cycle test to be performed. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic diagram showing a first embodiment of a characteristic test device according to the present invention; [Figure 2] FIG. 10 is a schematic diagram showing a second embodiment of a characteristic test device according to the present invention. [Figure 3] 10 is a graph showing a decrease in hydrogen gas temperature due to adiabatic expansion, which is the theoretical basis of the third embodiment of the characteristic test device of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. (First Example)

[0019] 1 is an explanatory diagram showing the schematic configuration of a characteristic test apparatus 1 according to a first embodiment of the present invention. The characteristic test apparatus 1 is equipped with a first container 3a and a second container 3b in which a first flat plate-shaped test piece 2a and a second flat plate-shaped test piece 2b are housed, respectively. Hereinafter, the letters a, b, ... attached to the reference numerals in the drawings will be used to indicate the parts related to the first container, the second container, ... and the systems connected thereto, respectively.

[0020] The characteristic test device 1 according to the first embodiment of the present invention includes a thermostatic chamber 4 that houses containers 3a and 3b. The thermostatic chamber 4 includes a thermometer 5 therein, which measures the temperature inside the thermostatic chamber 4 and allows the temperature inside the thermostatic chamber 4 to be set to a predetermined temperature.

[0021] In Figure 1, the characteristic test device of this first embodiment is explained using the example of placing two containers in one thermostatic chamber and testing the material properties of two test pieces simultaneously, but the characteristic test device 1 of the first embodiment of the present invention can also be applied to cases where three or more containers are stored in the thermostatic chamber 4, or where only one container is stored in the thermostatic chamber 4.

[0022] Furthermore, in FIG. 1, two containers are housed in one thermostatic chamber, but a thermostatic chamber 4a, 4b, . . . may be provided for each of the containers 3a, 3b, .

[0023] In the characteristic test device 1 of the first embodiment, the working spaces 6a and 6b of the first container 3a and the second container 3b housed in the thermostatic bath 4 are connected to each other by a working fluid communication system 7.

[0024] The first container 3a and the second container 3b each have working spaces 6a, 6b formed by the flat-plate-shaped test pieces 2a, 2b and upper container sections 8a, 8b having a generally inverted concave cross section, and passive spaces 10a, 10b formed by lower container sections 9a, 9b having a generally concave cross section and the back surfaces of the flat-plate-shaped test pieces 2a, 2b, which are spaced apart from the working spaces 6a, 6b across the flat-plate-shaped test pieces 2a, 2b. The containers 3a, 3b, which have the working spaces 6a, 6b and passive spaces 10a, 10b inside, are configured so that the upper container sections 8a, 8b and the lower container sections 9a, 9b can be opened and closed. The containers 3a, 3b are provided with metal or resin packings 11a, 11b, and when the upper container sections 8a, 8b and the lower container sections 9a, 9b are closed, the lower ends of the upper container sections 8a, 8b and the upper ends of the lower container sections 9a, 9b are overlapped via the packings 11a, 11b. This allows the containers 3a, 3b to be sealed, and sealed working spaces 6a, 6b and passive spaces 10a, 10b can be formed within the containers 3a, 3b.

[0025] The containers 3a and 3b in the first embodiment are made of metal containing at least one of iron, nickel, chromium, aluminum, and copper. The upper container sections 8a and 8b are cylindrical, disk-shaped, spherical, or rectangular with a bottom that opens downward, and the lower container sections 9a and 9b are cylindrical, disk-shaped, spherical, or rectangular with a bottom that opens upward.

[0026] The first container 3a and the second container 3b in the first embodiment may have the same or different shapes and dimensions. The first and second flat test pieces 2a and 2b may have the same or different shapes and dimensions, such as thickness and diameter, and materials.

[0027] In the characteristic test device 1 of the first embodiment of the present invention, a fluid supply system 12 is connected to the working space 6a in the upper container 8a, so that gas from a gas cylinder 13 is supplied to the working space 6a in the upper container 8a and further to the working space 6b in the upper container 8b through the working fluid communication system 7.

[0028] In the characteristic test apparatus 1 of the first embodiment, the fluid supply system 12 that supplies the fluid for creating a test environment to the working spaces 6a, 6b includes a regulator 14 that adjusts the pressure of the fluid supplied to the working spaces 6a, 6b from a gas cylinder 13. The fluid supply means may be configured to supply gas from the gas cylinder 13 via a compressor.

[0029] The fluid supply system 12 is provided with a fluid pressure gauge 15 that detects the pressure of the fluid on the outlet side of the regulator 14. The secondary pressure of the regulator 14 is adjusted based on the pressure detected by the fluid pressure gauge 15.

[0030] Furthermore, the characteristic test device 1 of this first embodiment is provided with a working space pressure gauge 17 for detecting the pressure in the working spaces 6a, 6b at at least one location in the working space 6a or the container inlet system 16, and is also provided with a working pressure adjustment means 18 and a working pressure fluctuation valve 19 that can adjust the pressure value of the working space pressure gauge 17 to a predetermined pressure value or a predetermined pressure fluctuation range.

[0031] Furthermore, the characteristic test device 1 of the first embodiment is equipped with a calculation means 20, and is configured so that the pressure waveform programmed in the calculation means 20 can be transmitted as a signal to the operating pressure adjustment means 18, thereby driving the operating pressure fluctuation valve 19 to the programmed pressure waveform.

[0032] The characteristic test apparatus 1 of the first embodiment also includes a fluid discharge system 21 that discharges the fluid from the working spaces 6a and 6b to the outside of the containers 3a and 3b. These fluid discharge systems 21 may be provided in the container inlet system 16 or the working spaces 6a and 6b.

[0033] In FIG. 1, a fluid supply system 12, an actuation pressure adjustment means 18, and an actuation pressure fluctuation valve 19 are provided for the actuation spaces 6a and 6b, but a similar fluid supply system, actuation pressure adjustment means, and actuation pressure fluctuation valve may be provided for the passive spaces 10a and 10b.

[0034] In this first embodiment, the operating pressure fluctuation valve 19 can be driven by air pressure upon receiving a signal from the operating pressure adjustment means 18 to set the valve opening, but the valve drive source can also be configured with a motor (electric motor), an electromagnet (solenoid), a piezoelectric element (piezo stack), etc.

[0035] In FIG. 1, the calculation means 20 includes a calculation circuit including, for example, a central processing unit (CPU), a programmable logic controller (PLC), and storage means (RAM and ROM).

[0036] Next, a test method using the characteristic test apparatus 1 of the first embodiment will be described. First, the flat test pieces 2a and 2b are placed on the upper ends of the lower container parts 9a and 9b, and then the lower ends of the upper container parts 8a and 8b are overlapped and sealed via packings 11a and 11b. This prevents fluid leakage from the overlapping parts between the upper ends of the lower container parts 9a and 9b and the lower ends of the upper container parts 8a and 8b.

[0037] The working space 6a in the upper part 8a of the container and the working space 6b in the upper part 8b of the container are connected by the working fluid communication system 7, and then the containers 3a and 3b are placed in the thermostatic bath 4, and the thermostatic bath 4 is operated so that the temperature of the thermometer 5 reaches a predetermined value.

[0038] Once the temperature inside the thermostatic chamber 4 has stabilized at a predetermined level, gas is supplied from a gas cylinder 13 to the working spaces 6a and 6b of the containers 3a and 3b via a fluid supply system 12. The pressure of the gas supplied to the working spaces 6a and 6b is adjusted by a regulator 14. At this time, the regulator 14 is controlled so as to maintain the detected pressure obtained from a fluid pressure gauge 15 constant. If the pressure in the gas cylinder 13 is low, a compressor is used instead of the regulator 14.

[0039] In the characteristic test device 1 of this first embodiment, by using a hydrogen gas cylinder as the gas cylinder 13 and filling the operating spaces 6a and 6b with hydrogen gas, it is possible to test the material characteristics of the flat test pieces 2a and 2b in a hydrogen gas environment.

[0040] During testing, the flat test specimens 2a, 2b are sandwiched between the upper and lower container sections 8a, 8b and 9a, 9b, and are fixed in place to isolate the working spaces 6a, 6b from the passive spaces 10a, 10b. The gas pressure of the working spaces 6a, 6b is applied to the upper surfaces of the flat test specimens 2a, 2b. A similar fluid supply system, working pressure adjustment means, and working pressure fluctuation valve may be provided for the passive spaces 10a, 10b, so that gas pressure can be applied to the passive spaces 10a, 10b below the flat test specimens 2a, 2b.

[0041] The pressure value or pressure waveform programmed and input into the calculation means 20, or the pressure or pressure waveform input by the tester, is then transmitted to the operating pressure adjustment means 18, which can adjust the opening of the operating pressure fluctuation valve 19 based on the transmitted data. Trapezoidal, triangular, sine, and rectangular waves can also be used as the pressure waveform.

[0042] Here, the period and waveform width of the pressure waveform can be set automatically, continuously, or randomly as necessary by the calculation means 20. As a result, a test can be performed to evaluate fatigue damage and fatigue fracture of the flat test pieces 2a and 2b by changing the pressure difference between the working spaces 6a and 6b and the passive spaces 10a and 10b.

[0043] Furthermore, in the characteristic test apparatus 1 of the first embodiment, the test piece is flat, but it is possible to perform characteristic tests on test pieces that are roughly flat, hemispherical, etc.

[0044] Furthermore, during the process of characteristic testing of the flat test pieces 2a, 2b using the characteristic testing device 1, when damage to the flat test pieces 2a, 2b progresses and cross leakage from the operating spaces 6a, 6b to the passive spaces 10a, 10b begins to increase, the amount of leakage can be detected using a gas concentration detector or the like.

[0045] Thus, with the characteristic test apparatus 1 of the first embodiment, rather than applying a load to the flat test specimens 2a, 2b using a hydraulic pump or cylinder, a bending load can be applied to the flat test specimens 2a, 2b by the pressure difference between the working spaces 6a, 6b and the passive spaces 10a, 10b that form the atmosphere in the thermostatic chamber 4, which is statically held at a predetermined temperature. This configuration eliminates the sliding part between the rod that previously applied a load to the test specimens using piston motion and the stationary hydrogen environment container over a wide temperature range, from extremely low to high temperatures. This reduces gas leaks, such as hydrogen, to a negligible level, ensuring high safety.

[0046] Furthermore, the characteristic testing device 1 of the first embodiment does not require mechanisms that apply load to the test piece, such as hydraulic pumps and cylinders, making it possible to create a very compact testing machine. As a result, it is possible to simultaneously test the material characteristics of multiple test pieces in various gas environments over a wide temperature range from extremely low to high temperatures.

[0047] Furthermore, in the first embodiment, gas is given as an example of the fluid supplied to the working spaces 6a and 6b, but the present invention is not limited to this. For example, the fluid may be either a liquid or gaseous substance at the test temperature. Examples of substances that are liquid at the test temperature include liquid water, alcohol, and oil. The fluid may be any of these. Examples of substances that are gaseous at the test temperature include reducing gases such as hydrogen, inert gases such as nitrogen and argon, rare gas elements such as helium, air, oxygen, and water vapor. The fluid may be any of these, or a mixture of these gases.

[0048] In the first embodiment, the containers 3a and 3b are configured with upper container sections 8a and 8b having a generally inverted concave cross section and lower container sections 9a and 9b having a generally concave cross section, but this is not limiting. The containers 3a and 3b may have an operating space between them and the test piece. The operating space may have at least a fluid passageway. For example, the containers 3a and 3b may have one or more concave grooves or a structure similar to a fuel cell separator. (Second Example)

[0049] According to the characteristic testing device of the second embodiment, material characteristics such as fatigue characteristics and leak characteristics of a plurality of flat test pieces can be tested simultaneously using fluids from a plurality of fluid supply systems.

[0050] Fig. 2 is a schematic diagram showing the configuration of a characteristic test apparatus according to a second embodiment. In Fig. 2, the characteristic test apparatus according to the second embodiment is described using an example in which two fluid supply systems are provided and fluids are supplied to the working spaces of two containers housed in a single thermostatic chamber, thereby simultaneously testing the material properties of two test pieces. However, the characteristic test apparatus 1 according to the second embodiment of the present invention can also be applied to a case in which three or more fluid supply systems are provided and three or more containers are housed in a thermostatic chamber.

[0051] Furthermore, in FIG. 2, one thermostatic bath is provided for two containers for two fluid supply systems, but a thermostatic bath may be provided for each container.

[0052] The characteristic test apparatus 1 of the second embodiment is basically the same as the characteristic test apparatus 1 of the first embodiment. Therefore, the following description will focus on the differences between the two, and corresponding parts will be denoted by the same reference numerals. Furthermore, a description of matters common to both embodiments will be omitted.

[0053] In the characteristic test apparatus 1 according to the second embodiment of the present invention, the first container 3a and the second container 3b each have working spaces 6a, 6b formed by the flat-plate-shaped test pieces 2a, 2b and upper container sections 8a, 8b having a generally inverted concave cross section, and passive spaces 10a, 10b formed by lower container sections 9a, 9b having a generally concave cross section and the back surfaces of the flat-plate-shaped test pieces 2a, 2b, which are spaced apart from the working spaces 6a, 6b across the flat-plate-shaped test pieces 2a, 2b. The containers 3a, 3b, which have the working spaces 6a, 6b and passive spaces 10a, 10b inside, are configured so that the upper container sections 8a, 8b and the lower container sections 9a, 9b can be opened and closed. The containers 3a, 3b are provided with metal or resin packings 11a, 11b, and when the upper container sections 8a, 8b and the lower container sections 9a, 9b are closed, the lower ends of the upper container sections 8a, 8b and the upper ends of the lower container sections 9a, 9b are overlapped via the packings 11a, 11b. This allows the containers 3a, 3b to be sealed, and sealed working spaces 6a, 6b and passive spaces 10a, 10b can be formed within the containers 3a, 3b.

[0054] In the characteristic test apparatus 1 according to the second embodiment of the present invention, fluid supply systems 12a and 12b are connected to the working spaces 6a and 6b in the upper container sections 8a and 8b, respectively, so that gas from gas cylinders 13a and 13b is supplied to the working spaces 6a and 6b in the upper container sections 8a and 8b.

[0055] The characteristic test apparatus 1 of the second embodiment also includes regulators 14a, 14b for adjusting the pressure of the fluid between the working spaces 6a, 6b and gas cylinders 13a, 13b as fluid supply means for supplying fluid to create a test environment in the working spaces 6a, 6b. The fluid supply means may be configured to supply gas from the gas cylinders 13a, 13b via a compressor.

[0056] The fluid supply systems 12a and 12b are provided with fluid pressure gauges 15a and 15b that detect the pressure of the fluid on the outlet side of the regulators 14a and 14b. The secondary pressure of the regulators 14a and 14b is adjusted based on the detected pressure of the fluid pressure gauges 15a and 15b.

[0057] Furthermore, the characteristic test device 1 of this second embodiment is provided with working space pressure gauges 17a, 17b that detect the pressure in the working spaces 8a, 8b at at least one location in the working spaces 6a, 6b or the container inlet systems 16a, 16b, and is provided with working pressure adjustment means 18a, 18b and working pressure fluctuation valves 19a, 19b that can adjust the pressure values ​​of the working space pressure gauges 17a, 17b to a predetermined pressure value or a predetermined pressure fluctuation range.

[0058] In addition, the characteristic test device 1 of this second embodiment is equipped with calculation means 20a, 20b, and is configured so that the pressure waveform programmed in the calculation means 20a, 20b can be transmitted as a signal to the operating pressure adjustment means 18a, 18b, and the operating pressure fluctuation valves 19a, 19b can be driven according to the programmed pressure waveform.

[0059] The characteristic test apparatus 1 of the second embodiment also includes fluid discharge systems 21a and 21b that discharge fluid from the working spaces 6a and 6b to the outside of the containers 3a and 3b. These fluid discharge systems 21a and 21b may be provided in the container inlet systems 16a and 16b or the working spaces 6a and 6b.

[0060] In FIG. 2, fluid supply systems 12a, 12b, actuation pressure adjustment means 18a, 18b, and actuation pressure fluctuation valves 19a, 19b are provided for the actuation spaces 6a, 6b, but similar fluid supply systems, actuation pressure adjustment means, and actuation pressure fluctuation valves may also be provided for the passive spaces 10a, 10b.

[0061] Next, a test method using the characteristic test apparatus 1 of the second embodiment will be described. First, the flat test pieces 2a and 2b are placed on the upper ends of the lower container parts 9a and 9b, and then the lower ends of the upper container parts 8a and 8b are overlapped and sealed via packings 11a and 11b. This prevents fluid leakage from the overlapping parts between the upper ends of the lower container parts 9a and 9b and the lower ends of the upper container parts 8a and 8b.

[0062] After the flat plate-shaped test pieces 2a, 2b are placed in the containers 3a, 3b in the thermostatic bath 4, the thermostatic bath 4 is operated so that the temperature of the thermometer 5 reaches a predetermined value.

[0063] The first container 3a and the second container 3b may be housed in a first thermostatic chamber 4a and a second thermostatic chamber 4b, respectively, so that the test temperatures of the first flat plate-shaped test piece 2a and the second flat plate-shaped test piece 2b can be set individually.

[0064] Next, the fluid supply systems 12a, 12b and the container inlet systems 16a, 16b are connected to the working spaces 6a, 6b of the containers 3a, 3b, respectively, to supply gas from the gas cylinders 13a, 13b to the working spaces 6a, 6b. In this case, the fluid in the working spaces 6a, 6b and the fluid in the passive spaces 10a, 10b are different types. For example, hydrogen cylinders are used as the gas cylinders 13a, 13b, and the working spaces 6a, 6b are filled with hydrogen gas, while the passive spaces 10a, 10b are filled with argon gas.

[0065] Depending on the characteristics test, the gas types for the first gas cylinder 13a and the second gas cylinder 13b can be selected separately, and the set pressures for the first regulator 14a and the second regulator 14b can be different. If the pressure of the gas supplied to the working spaces 6a and 6b is low, a compressor can be used instead of a regulator.

[0066] The pressure value or pressure waveform programmed and input into the calculation means 20a, 20b, or the pressure or pressure waveform input by the tester, is transmitted to the operating pressure adjustment means 18a, 18b, and the opening of the operating pressure fluctuation valves 19a, 19b can be adjusted based on the transmitted data. Trapezoidal waves, triangular waves, sine waves, and rectangular waves can also be used as the pressure waveform.

[0067] The pressure values ​​and pressure waves to be input to the first calculation means 20a and the second calculation means 20b can also be set individually by a characteristic test.

[0068] The period and waveform width of the pressure waveform can be set automatically, continuously, or randomly as necessary by the calculation means 20a, 20b. As a result, a static or variable bending load can be applied to the flat test pieces 2a, 2b by varying the pressure difference between the working spaces 6a, 6b and the passive spaces 10a, 10b, and a test can be performed to evaluate fatigue damage and fatigue fracture of the flat test pieces 2a, 2b.

[0069] More specifically, by installing a concentration analyzer in the passive spaces 10a and 10b and analyzing the gas concentration in the passive spaces 10a and 10b associated with fatigue damage and fatigue fracture of the flat test pieces 2a and 2b, the concentration of hydrogen leaked into the argon can be measured.

[0070] In the characteristic test apparatus 1 of the second embodiment, the fluid in the working spaces 6a, 6b may be, for example, a substance in a liquid state or a substance in a gaseous state at the test temperature. Substances in a liquid state at the test temperature may be liquid water, alcohol, or oil. Substances in a gaseous state at the test temperature may be hydrogen, nitrogen, air, oxygen, argon, helium, water vapor, or the like. (Third Example)

[0071] The characteristic test apparatus of the third embodiment is for testing the fatigue failure / fracture characteristics and leakage characteristics of test pieces at sub-zero temperatures, and is applicable to various devices, not limited to the first and second embodiments. Furthermore, since the configuration of the characteristic test apparatus 1 of the third embodiment is basically the same as the configuration of the characteristic test apparatus 1 of the first and second embodiments, a diagram of the configuration of the characteristic test apparatus of the third embodiment is not shown, and the theoretical background of the characteristic test apparatus of the third embodiment will be explained based on the analysis results of FIG. 3.

[0072] Fuel cell vehicles are typically equipped with hydrogen tanks in which hydrogen gas is compressed to high pressure and sealed inside. Electricity can be generated by reducing the hydrogen gas in these tanks to near atmospheric pressure and supplying it to the fuel cell stack. In this case, the adiabatic expansion of the hydrogen gas causes the temperature of the hydrogen tank to drop rapidly. Figure 3 shows the relationship between the ultimate temperature T2 (°C) and the initial hydrogen gas pressure P1 when hydrogen gas compressed to an initial pressure P1 (MPa) is adiabatically expanded to a final pressure P2 = 0.5 MPa at T1 = 25°C. Figure 3 analytically demonstrates that slightly compressed hydrogen can easily drop below freezing when it is decompressed and adiabatically expanded.

[0073] When the temperature of a hydrogen tank drops below freezing due to the adiabatic expansion of hydrogen gas, the components that make up the hydrogen tank are exposed to extremely low temperatures. If the hydrogen tank is made of metal materials, there is a risk that the hydrogen tank components will break due to hydrogen embrittlement. If the hydrogen tank is made of polymeric materials, there is a risk that the hydrogen tank components will break due to brittleness in the temperature range below the glass transition point.

[0074] To ensure the reliability of hydrogen tank components in low temperature ranges, a material property testing device is required that can test the material properties of the hydrogen tank components, such as fatigue damage / fracture characteristics and leak characteristics, in temperature ranges including below freezing.

[0075] The characteristic test apparatus 1 of this third embodiment is equipped with a thermostatic chamber 4 that can store containers 3a, 3b, etc. that have flat test pieces 2a, 2b, etc., and can set the containers 3a, 3b, etc. to a predetermined temperature.

[0076] The thermostatic bath 4 is configured to have a compressor therein, for example, and to maintain an extremely low temperature by repeating a refrigeration cycle of compression → condensation → expansion → evaporation of a fluid such as a refrigerant using the compressor. However, the thermostatic bath 4 is not limited to one that utilizes the principle of such a refrigeration cycle, and any bath that can maintain the interior of the thermostatic bath 4 below freezing point will do.

[0077] Next, the operation of the characteristic test apparatus 1 of the third embodiment will be described. First, in Figures 1 and 2, flat test pieces 2a, 2b,... are placed on the upper ends of the lower container parts 9a, 9b,... and then the lower ends of the upper container parts 8a, 8b,... are overlapped and sealed via packings 11a, 11b,... This prevents fluid leakage from the overlapping parts between the upper ends of the lower container parts 9a, 9b and the lower ends of the upper container parts 8a, 8b,...

[0078] After the flat test pieces 2a, 2b, ··· are placed in the containers 3a, 3b, ···, the thermostatic bath 4 or 4a, 4b, ··· is operated so that the temperature of the thermometer 5 reaches a predetermined value below freezing.

[0079] Once the temperature inside the thermostatic bath 4 or 4a, 4b, etc. has stabilized at a predetermined temperature below freezing, gas is supplied from the gas cylinder 13 or 13a, 13b, etc. to the working spaces 6a, 6b, etc. of the containers 3a, 3b, etc. via the fluid supply system 12 or 12a, 12b, etc. The gas supplied to the working spaces 6a, 6b, etc. is regulated by the regulators 14 or 14a, 14b, etc., respectively. At this time, the regulators 14 or 14a, 14b, etc. are controlled so as to maintain the detected pressure obtained from the fluid pressure gauge 15 or 15a, 15b constant.

[0080] In the characteristic test apparatus 1 of the first embodiment, by using a hydrogen gas cylinder for the gas cylinder 13 or 13a, 13b and filling the working spaces 6a, 6b with hydrogen gas, it becomes possible to test the material properties of the flat test pieces 2a, 2b in a hydrogen gas environment below freezing point. For example, if the test pieces 2a, 2b, ... are made of a metal material, it becomes possible to test hydrogen embrittlement below freezing point. Also, if the test pieces 2a, 2b, ... are made of a polymer material, it becomes possible to test fracture embrittlement in a temperature range below the glass transition point. [Industrial Applicability]

[0081] The present invention is applied to a characteristic testing device for simultaneously evaluating the gas permeability, fatigue characteristics, and other properties of materials exposed to a hydrogen environment at cryogenic temperatures on a plurality of test pieces. [Explanation of symbols]

[0081] 1...Characteristics test equipment 2a, 2b...Flat test piece (test piece) 3a, 3b...container 4, 4a, 4b…Thermostatic chamber 5, 5a, 5b…Thermometer 6a, 6b...Working space 7…Working fluid communication system 8a, 8b...Upper part of container 9a, 9b...bottom of container 10a, 10b...passive space 11a, 11b...Packing 12, 12a, 12b...Fluid supply system 13, 13a, 13b...Fluid supply means (gas cylinder) 14, 14a, 14b...Regulator 15, 15a, 15b...Fluid pressure gauge 16, 16a, 16b…Container inlet system 17, 17a, 17b...Working space pressure gauge 18, 18a, 18b...operating pressure adjusting means 19, 19a, 19b...Operating pressure fluctuation valve 20, 20a, 20b...calculation means 21, 21a, 21b...Fluid discharge system (Explanation of subscripts) a...represents the first container and the part of the system connected to the first container. b...Represents the second container and the part of the system connecting to the second container.

Claims

1. A characteristic test device for evaluating the characteristics or durability of a test piece in a fluid atmosphere, a plurality of containers each divided by the test pieces into an operating space and a passive space, each having a fixed volume, for accommodating the test pieces; a fluid supply means for supplying a fluid by connecting the plurality of working spaces formed between the container and the test piece contained therein; a pressure control means for controlling the pressure of the fluid supplied to the plurality of connected working spaces to apply a load to the plurality of test pieces; a thermostatic chamber for accommodating a plurality of the containers; A characteristic test device comprising:

2. A plurality of said containers; fluid supply means, the number of which is equal to the number of the containers, for supplying the fluid to the working spaces of the containers; pressure control means, the number of which is equal to the number of the containers, for controlling the pressure of the fluid supplied to the working space and applying a load to the test piece; 2. The characteristic test device according to claim 1, further comprising:

3. At least one constant temperature bath, including a constant temperature bath that has a refrigeration cycle that repeats compression → condensation → expansion → evaporation of the fluid and can set the temperature of the container below freezing point; 3. The characteristic test device according to claim 1, further comprising:

Images