CN-121977759-A - Leakage detection device under high strain ultralow temperature

CN121977759ACN 121977759 ACN121977759 ACN 121977759ACN-121977759-A

Abstract

The invention relates to the technical field of leakage detection, in particular to a leakage detection device under high strain and ultralow temperature, which comprises a stress loading assembly, a low temperature loading assembly and a leakage detection assembly, wherein the stress loading assembly is used for applying tensile stress to a workpiece to be detected, a fixing piece is used for fixing an upper cover plate and a lower cover plate, the upper cover plate and the lower cover plate are tightly abutted against the workpiece to be detected, cold sources can be filled in a first cavity and a third cavity, the cold sources can cool the workpiece to be detected to a test temperature, so that the temperature of an actual working scene of the workpiece to be detected is simulated, a pressure supply pump in the leakage detection assembly supplies pressure to a second cavity, and a vacuum pump in the leakage detection assembly is used for pumping gas in a fourth cavity, so that the leakage condition of the workpiece to be detected under the tensile stress and in the low temperature state is detected. The stress loading assembly can apply tensile stress to the workpiece to be detected to different degrees, and the cold source can reduce the workpiece to be detected to any different temperatures, so that the comprehensiveness of leakage detection to the workpiece to be detected is improved.

Inventors

CHANG YIPENG
SUN JIE
CHEN HAIJUN
ZHENG WENJIAN
YUE WEI

Assignees

苏州实验室

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (10)

1. A leak detection apparatus at high strain and ultra low temperature, comprising: The stress loading assembly is used for applying tensile stress to the workpiece to be tested; The low-temperature loading assembly comprises an upper cover plate and a lower cover plate, wherein the upper cover plate and the lower cover plate are arranged on the upper side and the lower side of a workpiece to be detected, the upper cover plate and the lower cover plate are connected through a fixing piece, a first cavity and a second cavity which are isolated from each other are arranged on the upper cover plate, a third cavity and a fourth cavity which are isolated from each other are arranged on the lower cover plate, the first cavity, the second cavity, the third cavity and the fourth cavity are all in contact with the workpiece to be detected, the first cavity is communicated with the third cavity, a cold source can be filled in the first cavity and the third cavity, and the cold source is used for cooling the workpiece to be detected; A leak detection assembly including a pressure supply pump to supply pressure to the second chamber and a vacuum pump to draw the fourth chamber gas.
2. The device for detecting leakage under high strain and ultralow temperature according to claim 1, wherein the stress loading assembly comprises a detection frame and a plurality of action cylinders, the action cylinders are fixedly arranged on the detection frame and uniformly distributed in the circumferential direction of a workpiece to be detected, each action cylinder is provided with a telescopic output end, and each output end of each action cylinder is provided with a connecting piece which is used for connecting the workpiece to be detected with the output end of each action cylinder.
3. The device for detecting leakage under high strain and ultralow temperature according to claim 2, wherein the connecting piece comprises a fixed plate and two extrusion plates, the fixed plate is fixedly connected to the output end, the two extrusion plates are arranged on the upper side and the lower side of the workpiece to be detected at intervals, the extrusion plates are in sliding connection with the fixed plate, locking bolts are arranged between the two extrusion plates, and the locking bolts can promote the two extrusion plates to clamp the workpiece to be detected.
4. The leakage detection device under high strain and ultralow temperature according to claim 1 is characterized in that a first sealing piece is arranged between the upper cover plate and a workpiece to be detected, a first notch is formed in the first sealing piece and used for enabling the first cavity and the second cavity to be in direct contact with the workpiece to be detected, a second sealing piece is arranged between the lower cover plate and the workpiece to be detected, a second notch is formed in the second sealing piece and used for enabling the third cavity and the fourth cavity to be in direct contact with the workpiece to be detected.
5. The device for detecting leakage at a high strain and ultra-low temperature as claimed in claim 4, wherein a supply pipe is arranged on the lower cover plate or the upper cover plate, the supply pipe is communicated with the first chamber or the third chamber, and a supply pump is arranged on the supply pipe and is used for supplying the cold source to the first chamber or the third chamber.
6. The device for detecting leakage at a high strain and ultralow temperature according to claim 5, wherein the cold source is liquid nitrogen.
7. The leakage detection device under high strain and ultralow temperature according to claim 1, wherein the pressure supply pump is fixedly arranged on the upper cover plate, an air outlet of the pressure supply pump is arranged in the second chamber, a detection pipe is arranged on the lower cover plate in a penetrating manner, the detection pipe is used for communicating the fourth chamber with the external environment, and the vacuum pump is arranged at the tail end of the detection pipe.
8. The device for detecting leakage under high strain and ultralow temperature according to claim 1, wherein the upper cover plate is further provided with a safety valve communicated with the third chamber and the external environment.
9. The device for detecting leakage at a high strain and ultra-low temperature as claimed in claim 1, wherein the fixing member comprises a plurality of locking screws, the locking screws are uniformly distributed in the circumferential direction of the upper cover plate and the lower cover plate, and the locking screws penetrate through the upper cover plate and the lower cover plate at the same time.
10. The leakage detection device under high strain and ultralow temperature according to claim 1, wherein the first chamber and the third chamber are communicated with each other through a communicating pipe.

Description

Leakage detection device under high strain ultralow temperature Technical Field The invention relates to the technical field of leakage detection, in particular to a leakage detection device under high strain and ultralow temperature. Background In the field of aerospace, the lightweight design of a storage tank of an aerospace carrier is the core direction for improving the carrying efficiency, the storage tank material is gradually transited from a traditional alloy to a carbon fiber composite material, however, the service environment of the storage tank of the carrier is extreme, complex mechanical loading and ultralow temperature corrosion are required to be borne at the same time, the leakage performance of the carbon fiber composite material is obviously attenuated due to the coupling effect of the two environments, and the operation safety of the storage tank is directly threatened. The development of helium leakage test of carbon fiber composite materials in high-strain ultralow temperature state is a core means for exploring leakage failure mechanism, and the test is based on a helium leakage detection device capable of cooperatively operating in tensile strain state and ultralow temperature environment. The existing detection mode has obvious limitations that firstly, the conventional method is used for carrying out detection after a helium tool is soaked in an extremely low-temperature environment, the low-temperature and strain coupling state in a real service scene cannot be simulated, the deviation between a test result and an actual working condition is large, the reference value is limited, and secondly, the partial scheme is used for carrying out helium detection after liquid nitrogen is filled into a pressure container structural member, but the mode has a plurality of defects that the cost of the structural member for testing is high, the sealing difficulty of a full composite material pressure container in the low-temperature environment is extremely high, the testing focus is focused on the problem of integral leakage of the structural member, the leakage performance of a carbon fiber composite material cannot be accurately judged and analyzed, and the study of a failure mechanism of a material layer is difficult to support. Disclosure of Invention The invention provides a leakage detection device under high strain and ultralow temperature, which aims to solve the problem that the existing detection device cannot simultaneously meet the requirement of detecting the leakage of a carbon fiber composite material under strain and low temperature. The invention relates to a leakage detection device under high-strain ultralow temperature, which adopts the following technical scheme: A leakage detection device under high strain and ultralow temperature comprises a stress loading assembly, a low temperature loading assembly and a leakage detection assembly. The low-temperature loading assembly comprises an upper cover plate and a lower cover plate, the upper cover plate and the lower cover plate are arranged on the upper side and the lower side of a workpiece to be detected, the upper cover plate and the lower cover plate are connected through fixing pieces, a first cavity and a second cavity which are isolated from each other are arranged on the upper cover plate, a third cavity and a fourth cavity which are isolated from each other are arranged on the lower cover plate, the first cavity, the second cavity, the third cavity and the fourth cavity are all in contact with the workpiece to be detected, the first cavity is communicated with the third cavity, cold sources can be filled in the first cavity and the third cavity, the cold sources are used for cooling the workpiece to be detected, and the leak detection assembly comprises a pressure supply pump for supplying pressure to the second cavity and a vacuum pump for pumping gas of the fourth cavity. Further, the stress loading assembly comprises a detection frame and a plurality of action cylinders, the action cylinders are fixedly arranged on the detection frame and uniformly distributed in the circumferential direction of the workpiece to be detected, each action cylinder is provided with a telescopic output end, each output end of each action cylinder is provided with a connecting piece, and the connecting pieces are used for connecting the workpiece to be detected with the output ends of the action cylinders. Further, the connecting piece includes fixed plate and two stripper plates, fixed plate fixed connection in the output, two the stripper plate interval sets up the upper and lower both sides of workpiece to be measured, the stripper plate with fixed plate sliding connection is provided with locking bolt between the two the stripper plate, locking bolt can promote two the stripper plate carries out the centre gripping with the workpiece to be measured. Further, a first sealing piece is arranged between the upper cover plate and the wo