KR100915790B1 - stress - strain measuring apparatus using bellows structure - Google Patents

Abstract

A load-strain gauge using a bellows structure is disclosed. The present invention disclosed is a bellows structure 100 is elastically stretched and the thrust is generated; Load applying means (200) for transmitting the thrust generated by the bellows structure (100) to a test piece (T); Gas pressure control means 300 for adjusting the pressure of the gas flowing into the bellows structure 100, outflow; And measuring means 400 for continuously measuring the load and strain imposed on the test piece T. According to this, a measuring apparatus can be comprised compactly and simply using the metal bellows pipe 110, without employing a hydraulic pump and a hydraulic cylinder.

Description

Stress-strain measuring apparatus using bellows structure

The present invention relates to a load-strain measuring device using a bellows structure, and in particular, employing a metal bellows tube that elastically expands and contracts by gas pressure without using an electrically operated hydraulic pump and a hydraulic cylinder. The present invention relates to a measuring device capable of applying and measuring various modes of load on a specimen by precisely controlling the gas pressure inside the bellows pipe.

Conventional load-strain gauges are equipped with an electric motor or a hydraulic pump and a hydraulic cylinder to apply a load to a test piece, and are designed to obtain a large load by the pressure of the fluid acting on the piston of the hydraulic cylinder. However, the conventional measuring device configured as described above must be equipped with an electric motor, a hydraulic pump, a cylinder, a piston, and a hydraulic transmission structure to generate power, so that the complexity and enlargement of the device are inevitable.

In order to evaluate the integrity of materials used in nuclear reactors, it is essential to inspect the nuclear reactor structural materials (in-service system) and simulated irradiation tests in the irradiation test hole of the research reactor during operation of the reactor. In-service inspection and investigation of research reactors The testing of material properties in test holes is usually carried out in long, narrow spaces and in harsh environments where neutrons are irradiated. There must be features that can be controlled. In addition, the load application system using the conventional liquid fluid has a high risk of liquid fluid leakage at the core of the reactor and there is a problem of sealing leakage between the piston and the inner wall of the cylinder. In order to safely perform material testing in a nuclear reactor environment, a device is required to ensure the high temperature sealability of the load-bearing fluid on the specimen.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and does not use electrically driven electric motors, hydraulic pumps and hydraulic cylinders and liquid fluids, and can maintain elasticity at high temperatures and elastically expandable metal bellows. It is an object of the present invention to provide a load-strain measuring device using a bellows structure in which various and precise loads are applied to a material under test using a tube to measure a strain accordingly.

The present invention for achieving the above object, the bellows structure 100 is elastically stretched and the thrust is generated by the gas pressure; Load applying means (200) for transmitting the thrust generated by the bellows structure (100) to a test piece (T); Gas pressure control means 300 for adjusting the pressure of the gas flowing into the bellows structure 100, outflow; And measuring means 400 for continuously measuring the load and strain imposed on the test piece (T).

According to a preferred embodiment of the present invention, the bellows structure 100, Bellows pipe 110 is elastically stretched by the gas pressure; Connecting flanges 120 which extend to upper and lower ends of the bellows pipe 110 and are connected to the load-bearing means 200 through fastening means; And a sealing plate interposed between the connection flange 120 and the load applying means 200 to seal the bellows pipe 110 and transmitting a thrust generated by gas pressure to the load applying means 200. 130; characterized in that it comprises a.

Here, the thrust generated in the bellows pipe 110 is

(Bellows cross-sectional area) x (bellows internal pressure)-(bellows spring constant) x (bellows deformation).

In addition, the bellows pipe 110 is characterized in that the material is made of stainless steel.

According to a preferred embodiment of the present invention, the load-bearing means 200, the upper fixing plate 221 is fixed to the upper end of the bellows structure 100 and the lower portion spaced apart from the lower fixing plate 221 The fixing plate 223 and the middle fixing plate 222 and the upper fixing plate 221 and the middle fixing plate 222 and the lower fixing plate 223 fixed between the upper movable plate 211 and the lower movable plate 213 A fixed frame 220 including a connecting shaft 224 for connecting;

The upper movable plate 211 is fixed to the lower end of the bellows structure 100 and is lowered and lowered in accordance with the thrust generated by the bellows structure 100, and spaced apart from the lower portion of the intermediate fixing plate 222, and the upper movable plate. A lower transfer plate 213 interlocked with the 211, a load transfer shaft 212 connecting the upper transfer plate 211 and the lower transfer plate 213, and fixed to the intermediate fixing plate 222. An upper fixing shaft 231 installed below the middle fixing plate 222, a lower moving shaft 232 fixed to the lower moving plate 213, and installed on an upper portion of the lower moving plate 213 and the upper fixing shaft; 231 and the moving frame 210 is installed at each end of the lower movable shaft 232 to support both ends of the test piece (T) and includes a coupling 230 detachable of the test piece (T); Characterized in that made.

Here, the upper portion of the lower fixing plate 223 may be further provided with a stopper 240 to mitigate the impact of the moving frame 210 when the test piece (T) is broken.

In addition, the intermediate fixing plate 222 may be further provided with a bushing 225 coupled to the load transfer shaft 212 to guide the load transfer shaft 212.

In addition, the gas pressure control means 300, the gas buffer 310 for supplying or recovering gas to the bellows structure 100 to prevent the internal gas pressure of the bellows structure 100 is changed rapidly; A pressure transducer 311 measuring the pressure of the gas buffer 310 and converting the pressure into an electrical signal; The amount of gas flowing into or out of the inlet gas regulating valve 321 and the outflow gas regulating valve 322 and the gas buffer 310 to precisely control the amount of gas flowing into or out of the gas buffer 310. An inlet gas solenoid valve 331 and an outlet gas solenoid valve 332 for rapidly regulating the valve; A micro gas controller 320 for controlling the inflow gas control valve 321 and the outflow gas control valve 322; A solenoid controller 330 and a solenoid opening and closing controller 333 for controlling the inflow gas solenoid valve 331 and the outflow gas solenoid valve 332; And a selector 340 that selects a controller to perform control by receiving an electrical signal from the pressure transducer 311 or the measuring means 400.

In addition, the measurement means 400, the load cell is installed on the upper fixed shaft 231 to measure the load applied to the test piece (T) and converts it into an electrical signal to the gas pressure control means 300 ( 410); A micrometer 420 disposed at a lower end of the intermediate fixing plate 222 to measure an absolute amount of a moving distance of the moving frame 210; And measuring a change amount of the test piece T through the measuring core 431 fixedly installed on the intermediate fixing plate 222 and the lower movable plate 213 to be deformed in the same manner as the test piece T, and converting the converted amount into an electrical signal. Displacement transducer 430 (LVDT); characterized in that it comprises a.

Due to the present invention as described above, by adopting a flexible metal bellows pipe, instead of an electric motor, a hydraulic pump and a hydraulic cylinder, and a gas pressure control means for precisely adjusting the internal pressure of the bellows pipe, a load applying means for mechanical testing of materials By miniaturizing, it is possible to perform material test during reactor operation in a narrow and narrow space such as a research hole of a research reactor.

In addition, the use of the bellows tube has the other effect of improving the safety during material testing in a neutron irradiation environment because it is possible to maintain a good high temperature sealability structurally without using a liquid fluid.

In addition, the appropriate adjustment of the dimensions of each component of the present invention is expected to have an additional effect that can be manufactured to be used in various forms of space.

In addition, the present invention can precisely control the load during material testing, structurally simple, miniaturized, and can be manufactured at a low cost, so in addition to neutron irradiation test, material creep test, constant elongation tester for corrosion test, fatigue-creep tester There is another effect that can be easily applied to the back.

1 is a view schematically showing a load-strain measuring device using a bellows structure according to an embodiment of the present invention,

2 is an enlarged view of the bellows pipe 110 of FIG. 1;

3 is a view showing the flow of the gas pressure control means 300 for controlling the bellows pipe 110 of FIG.

<Description of Symbols for Main Parts of the Present Invention>

100; Bellows structure 110; Bellows tube

120; Connection flange 121; volt

130; Sealing plate 200; Load-bearing means

210; Moving frame 211; Upper plate

212; Load transfer shaft 213; Lower transfer plate

220; Fixed frame 221; Upper fixing plate

222; Intermediate fixation plate 223; Bottom fixing plate

224; Consolidation 225; bushing

230; Coupling 231; Upper fixed shaft

232; Lower fixed shaft 240; stopper

300; Gas pressure control means 310; Gas buffer

311; Pressure transducer 320; Micro Gas Controller

321; Inlet gas control valve 322; Outflow Gas Control Valve

330; Solenoid controller 331; Inlet Gas Solenoid Valve

332; Outflow gas solenoid valve 333; Solenoid Switch Controller

340; Selector 350; Manual Valve

360; Helium gas cylinder 370; A / D converter

400; Measuring means 410; Load cell

420; Micrometa 430; Displacement Transducer (LVDT)

431; Measuring core T; Test piece

The above objects and other features of the present invention will become more apparent by describing the preferred embodiments of the present invention in detail with reference to the accompanying drawings. For reference, in the following description of the present invention, if it is determined that a detailed description of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is a view schematically showing a load-strain measuring device using a bellows structure according to an embodiment of the present invention, Figure 2 is an enlarged view showing the bellows pipe 110 of FIG. 3 is a view showing the flow of the gas pressure control means 300 for controlling the bellows pipe 110 of FIG.

Referring to Figures 1 to 3, the present invention is elastically stretched while the bellows structure 100 is generated thrust (推力), the load for transmitting the thrust generated by the bellows structure 100 to the test piece (T) Imposing means 200 Measuring means 400 for continuously measuring the load and deformation imposed on the gas pressure control means 300 and the test piece (T) to adjust the pressure of the gas flowing into the bellows structure 100, outflow It includes.

The bellows structure 100, the bellows pipe 110 is elastically stretched and the thrust generated by the gas pressure (110); Connecting flanges 120 which extend to upper and lower ends of the bellows pipe 110 and are connected to the load-bearing means 200 through fastening means; And a sealing plate interposed between the connection flange 120 and the load applying means 200 to seal the bellows pipe 110 and transmitting a thrust generated by gas pressure to the load applying means 200. 130; characterized in that it comprises a. Wherein the fastening means is shown as a bolt (121). In addition, since the material of the bellows pipe 110 is made of stainless steel, it has a high durability.

The load applying means 200, the upper fixing plate 221 is fixed to the upper end of the bellows structure 100, the lower fixing plate 223 is provided to be spaced apart below the upper fixing plate 221 and the upper movement An intermediate fixing plate 222 fixed between the plate 211 and the lower movable plate 213 and a connecting shaft 224 connecting the upper fixing plate 221 and the intermediate fixing plate 222 and the lower fixing plate 223. The fixed frame 220 is configured.

In addition, the load-carrying means 200 is fixed to the lower end of the bellows structure 100 and the upper movable plate 211 is lowered in accordance with the thrust generated in the bellows structure 100 and the intermediate fixing plate 222 A lower portion of the movable plate 213 spaced apart from the upper movable plate 211 and interlocked with the upper movable plate 211, and a load transfer shaft 212 connecting the upper movable plate 211 and the lower movable plate 213; The upper fixing shaft 231 is fixed to the middle fixing plate 222 and installed below the middle fixing plate 222, and is fixed to the lower moving plate 213 and installed to the upper portion of the lower moving plate 213. It is installed at the end of the lower movable shaft 232 and the upper fixed shaft 231 and the lower movable shaft 232 to support both ends of the test piece (T) and includes a coupling 230 that can be attached and detached of the test piece (T) The moving frame 210 is configured.

In addition, the upper portion of the lower fixing plate 223 is provided with a stopper 240 to mitigate the impact of the moving frame 210 when the test piece (T) is broken, the intermediate fixing plate 222 is the load transfer shaft 212 Is coupled to the bushing 225 for guiding the load transfer shaft 212.

The gas pressure control means 300 may include: a gas buffer 310 supplying or recovering gas to the bellows structure 100 to prevent the internal gas pressure of the bellows structure 100 from being rapidly changed; A pressure transducer 311 measuring the pressure of the gas buffer 310 and converting the pressure into an electrical signal; The amount of gas flowing into or out of the inlet gas control valve 321 and the outflow gas control valve 322 and the gas buffer 310 to precisely control the amount of the gas flowing into or out of the gas buffer 310. An inlet gas solenoid valve 331 and an outlet gas solenoid valve 332 which are rapidly adjusted; A micro gas controller 320 for controlling the inflow gas control valve 321 and the outflow gas control valve 322; A solenoid controller 330 for controlling the inflow gas solenoid valve 331 and the outflow gas solenoid valve 332 and a solenoid opening and closing controller 333 for controlling the opening / closing time thereof; And a selector 340 that selects a controller to perform control by receiving an electrical signal from the pressure transducer 311 or the measuring means 400. Reference numeral 350, which is not described, denotes a manual valve 350 provided with a plurality of required positions and configured to manually operate the flow rate, where 360 is a helium gas cylinder 360 in which gas is first stored and supplied, and 370 is a load cell 410. Or A / D converter 370 converts the value measured by the displacement transducer 430 to a voltage signal and sends it to the display device of the computer.

The measuring means 400 is installed on the upper fixed shaft 231 to measure the load applied to the test piece (T) and converts it into an electrical signal to the A / D converter 370 of the gas pressure control means 300 A load cell 410 which is transmitted to the display device of the personal computer or transmitted to each controller for controlling the load; A micrometer 420 disposed at a lower end of the intermediate fixing plate 222 to measure an absolute amount of a moving distance of the moving frame 210; And measuring a change amount of the test piece T through the measuring core 431 fixedly installed on the intermediate fixing plate 222 and the lower movable plate 213 to be deformed in the same manner as the test piece T, and converting the converted amount into an electrical signal. Displacement transducer 430 (LVDT); characterized in that it comprises a.

Due to the structure as described above, the internal pressure due to the gas is applied to the bellows pipe 110, the thrust is generated, the upper transfer plate 211 is moved downward by the generated thrust, and thus the load transfer shaft 212 bushing The lower movable plate 213 is pushed through 225. The force acting on the lower movable plate 213 is transmitted to the test piece T by the coupling 230 to act as a tensile force. Here, the thrust generated in the bellows pipe 110 is calculated by the formula (bellows cross-sectional area) x (bellows internal pressure)-(bellows spring constant) x (bellows deformation amount).

The present invention has been described in an exemplary manner. The terminology used herein is for the purpose of description and should not be regarded as limiting. Many modifications and variations of the present invention are possible in light of the above teachings. Accordingly, the invention may be freely practiced within the scope of the claims unless otherwise stated.

Claims (9)

delete delete delete delete A bellows structure 100 that is elastically stretched and has a thrust generated by gas pressure; Load applying means (200) for transmitting the thrust generated by the bellows structure (100) to a test piece (T); Gas pressure control means 300 for adjusting the pressure of the gas flowing into the bellows structure 100, outflow; And It includes; measuring means 400 for continuously measuring the load and deformation applied to the test piece (T), The load applying means 200, An upper fixing plate 221 to which an upper end of the bellows structure 100 is fixed; A lower fixing plate 223 spaced apart from the lower fixing plate 221, and An intermediate fixing plate 222 fixed between the upper movable plate 211 and the lower movable plate 213; A fixing frame 220 including a connecting shaft 224 connecting the upper fixing plate 221, the middle fixing plate 222, and the lower fixing plate 223; An upper movable plate 211 fixed to a lower end of the bellows structure 100 and lowered according to the thrust generated by the bellows structure 100;  A lower movable plate 213 spaced apart from the lower fixing plate 222 and interlocked with the upper movable plate 211; A load transfer shaft 212 connecting the upper movable plate 211 and the lower movable plate 213; The upper fixing shaft 231 is fixed to the middle fixing plate 222 and installed below the middle fixing plate 222, and is fixed to the lower moving plate 213 and installed to the upper portion of the lower moving plate 213. Lower movable shaft 232 and A moving frame 210 installed at each end of the upper fixed shaft 231 and the lower movable shaft 232 to support both ends of the test piece T and a coupling 230 detachable from the test piece T; ; Load-strain measuring device using a bellows structure, characterized in that comprises a. The method of claim 5, wherein The upper part of the lower fixing plate 223, the load-strain measuring device using a bellows structure, characterized in that the stopper 240 is further provided to mitigate the impact of the moving frame 210 when the test piece (T) is broken. The method according to claim 5 or 6, The intermediate fixing plate (222) is coupled to the load transfer shaft (212) is a load-deflection measuring instrument using a bellows structure, characterized in that further provided with a bushing (225) for guiding the load transfer shaft (212). The method of claim 5, wherein the gas pressure control means 300, A gas buffer 310 for supplying or recovering gas to the bellows structure 100 to prevent the internal gas pressure of the bellows structure 100 from being rapidly changed; A pressure transducer 311 measuring the pressure of the gas buffer 310 and converting the pressure into an electrical signal; The amount of gas flowing into or out of the inlet gas control valve 321 and the outflow gas control valve 322 and the gas buffer 310 to precisely control the amount of the gas flowing into or out of the gas buffer 310. An inlet gas solenoid valve 331 and an outlet gas solenoid valve 332 which are rapidly adjusted; A micro gas controller 320 for controlling the inflow gas control valve 321 and the outflow gas control valve 322; A solenoid controller 330 and a solenoid opening and closing controller 333 for controlling the inflow gas solenoid valve 331 and the outflow gas solenoid valve; And a selector (340) for selecting a controller to perform control by receiving an electrical signal from the pressure transducer (311) or the measuring means (400). The method of claim 5, wherein the measuring means 400, A load cell 410 installed on the upper fixed shaft 231 and measuring a load applied to a test piece T and converting the load to a gas signal to the gas pressure control means 300; A micrometer 420 disposed at a lower end of the intermediate fixing plate 222 to measure an absolute amount of a moving distance of the moving frame 210; And A displacement that is fixed to the intermediate fixing plate 222 and the lower movable plate 213 to measure the amount of change of the test piece (T) through the measuring core 431 deformed in the same manner as the test piece (T) to convert it into an electrical signal Transducer (430) (LVDT); load-strain measurement using a bellows structure, characterized in that it comprises a.