A sample cooling device for room temperature fatigue test

Abstract

The present invention discloses a sample cooling device for room temperature fatigue test, which belongs to the technical field of material mechanical property test. The cooling device includes three parts: an air compressor, a support component and a cooling ring; the air compressor is used to provide cooling source compressed air, which is transported to the cooling ring through the support component, and then sprayed onto the surface of the fatigue sample through the exhaust port opened on the cooling ring, thereby achieving cooling of the sample to be tested. The device can effectively use compressed air to evenly cool the sample to be tested, and will not affect the organizational properties of the material during the test, thereby greatly increasing the test frequency, thereby accelerating the test cycle and reducing the test cost.

Description

Technical Field

[0001] The invention relates to the technical field of material mechanical property testing, and in particular to a novel sample cooling device for room temperature fatigue testing. Background Art

[0002] Fatigue is a problem that materials must face in the actual application process. Fatigue-induced component failure accounts for about 80% of all component failures. Fatigue fractures are often sudden and catastrophic, so material fatigue is an inevitable obstacle in the actual application of components. Obtaining accurate material fatigue data is an essential link before the material is actually applied, so it is particularly important to be able to quickly and accurately measure the fatigue performance of the material. For fatigue testing, if the requirements are met, the faster the test frequency, the faster the efficiency, the shorter the test cycle, and the lower the test cost, the more conducive to the promotion and application of materials.

[0003] During the room temperature fatigue test, the faster the frequency, the better, under the premise of ensuring that the specimen does not heat up and the external load is accurate. For most materials, the faster fatigue test frequency will not cause heating during the test. In this way, the test frequency can be increased as quickly as possible under the premise that the material does not heat up during the test. For the electro-hydraulic servo fatigue testing machine, the test frequency of general materials is 40-50Hz, the cost is 100-200 yuan / hour, and each group of materials requires about 300 hours of testing time. However, some materials are very sensitive to the heating caused by frequency. Once the material heats up, it may cause changes in the internal structure of the material, resulting in invalid test data. Therefore, in order to ensure the accuracy of the test data, the test frequency can only be greatly reduced. The test frequency of some materials may even be reduced to 2Hz. The time cost and cost required for calculation according to the same test parameters will increase by 20 times, greatly increasing the difficulty of material development.

[0004] The traditional cooling method is to use coolant refrigeration or liquid nitrogen refrigeration. However, these methods have defects. Coolant refrigeration requires that the specimen must be immersed in the coolant, but the testing machine equipment is always vibrating during the entire test process. During the experiment, it is inevitable that the coolant will leak due to vibration. The leaked coolant will corrode the workbench or actuator of the fatigue testing machine, and in severe cases, it may even cause damage to the testing machine. The maintenance cost ranges from tens of thousands to hundreds of thousands. Liquid nitrogen refrigeration uses the heat absorbed by liquid nitrogen when it vaporizes to remove the heat generated by the frequency, but this cooling method has two defects: 1) The liquid nitrogen vaporization process will quickly absorb the surrounding heat, causing the surrounding temperature to drop rapidly, and the moisture in the surrounding air will liquefy into small water droplets and gather on the surface of the sample. The small water droplets will corrode the material and cause inaccurate test results; in addition, the gathered small water droplets will flow along the test material to the test machine, which will corrode the test machine fixture and workbench, and will also accelerate the aging of the test machine, thereby increasing the test cost; 2) Fatigue testing is a long-term working process. It is very normal for a material sample to work for dozens of hours during fatigue testing. The cost of liquid nitrogen is very high and it is consumed very quickly. In this process, once the liquid nitrogen is consumed and cannot be replenished in time, the sample will quickly heat up and make the test results invalid, which will also increase the cost of the test.

[0005] In order to improve the accuracy of fatigue testing of materials, speed up the fatigue testing cycle of heat-generating materials, and provide a reliable reference for the subsequent use of components, it is necessary to improve the existing fatigue testing equipment. Summary of the invention

[0006] The purpose of the present invention is to provide a sample cooling device for room temperature fatigue testing, which can effectively use compressed air to evenly cool the test sample and will not affect the material's organizational properties during the test, thereby greatly increasing the test frequency, thereby accelerating the test cycle and reducing the test cost.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A sample cooling device for room temperature fatigue test comprises three parts: a compressor, a support component and a cooling ring; the compressor is used to provide cooling source compressed air, the compressed air is transported to the cooling ring through the support component, and then sprayed onto the surface of the fatigue sample through the exhaust holes provided on the cooling ring, thereby achieving cooling of the sample to be tested.

[0009] The support component is a cylindrical structure with a mounting hole at one end for connection to a fatigue testing machine; an air inlet is also provided on the side wall of the support component close to the mounting hole, the air inlet is connected to an air inlet pipe in the support component, and the air inlet pipe is communicated with the interior of the cooling ring.

[0010] The other end of the support component is provided with four air outlets, and the air inlet pipe includes a main pipe and four branches branching from the main pipe, and the four branches are respectively connected to the four air outlets; the compressed air generated by the compressor is input into the cooling ring through the air inlet I, the air inlet pipe main pipe, the air inlet pipe branch and the air outlet in sequence.

[0011] The cooling ring is assembled from four hollow cooling bodies of the same structure, wherein the hollow cooling body includes a semi-annular structure and a connecting portion, and three hollow shafts are arranged on the semi-annular structure; one free end of the semi-annular structure is closed, and the other free end is provided with a connecting portion, and a columnar tube is arranged on the connecting portion; the columnar tube and the three hollow shafts are all arranged on the same side surface of the hollow cooling body.

[0012] The four hollow cooling bodies of the cooling ring with the same structure are assembled in pairs, specifically: the semi-annular structures of the two hollow cooling bodies are placed opposite to each other to form a circular ring, and the columnar tubes on the two hollow cooling bodies are respectively extended into the air outlets at the ends of the supporting part, and a sealing ring is provided in the air outlet to facilitate the formation of a sealing structure after the columnar tube is extended into the air outlet; the semi-annular structure can rotate along the columnar tube extended into the supporting part. After the semi-annular structures of the other two hollow cooling bodies are placed opposite to each other to form a circular ring, the hollow shafts on the two circular structures formed are connected one by one, and the columnar tubes on the other two hollow cooling bodies are also extended into the air outlet at the end of the supporting part.

[0013] The hollow shaft is provided with a longitudinal row of exhaust holes, and a rotatable baffle is also mounted on the hollow shaft. The rotation of the baffle can control whether each hollow rotating shaft discharges gas, thereby regulating the discharge amount and discharge position of the gas discharged from the entire device.

[0014] The support component and the cooling ring are made of polymer resin 3D printing.

[0015] The air compressor is provided with a pressure regulating valve, which can control the pressure of the provided compressed air.

[0016] The advantages and beneficial effects of the present invention are as follows:

[0017] 1. The present invention designs a cooling device for fatigue specimens, which uses compressed air to cool the experimental materials. Without damaging the material surface, fatigue testing machine, and ensuring the accuracy of experimental data, the device can largely solve the heating problem of the material during the experiment due to the increase in frequency, which greatly improves the test efficiency and accuracy of the material fatigue test. In addition, the device can adjust the cooling speed of the specimen by adjusting the compressed air pressure, the position of the air outlet, and the number of air outlets according to different specimen sizes, and has the characteristics of wide applicability, low use cost, and simple maintenance.

[0018] 2. The support component and cooling ring described in the present invention are made of polymer resin 3D printing, and have the characteristics of good sealing, low density and good aesthetics. The air compressor is mainly used to provide compressed air as a cooling source. The compressed air provided by the air compressor is evenly sprayed on the surface of the sample through the exhaust port on the cooling ring. The compressed air can take away the heat generated by the sample due to the increase in frequency without affecting the material structure. Moreover, the device reduces the temperature of the sample material by accelerating the air flow around the sample material without drastically reducing the air temperature around the sample material. Therefore, there will be no condensed water generated to damage the fatigue testing machine. In addition, the air compressor only needs electricity to work, and electricity is a relatively stable output. Therefore, this cooling method can be provided stably, and the use cost and maintenance cost are very low, and will not increase the overall test cost.

[0019] 3. After using the cooling device of the present invention in fatigue testing, the heating problem that occurs during the fatigue process of certain materials is effectively solved. The entire cooling process will not affect the test materials and will not damage the fatigue testing machine; the use and maintenance costs of the entire set of equipment are very low, and the use of the detachable cooling ring can extend the service life of the cooling device. Practice has proved that the use of this device can increase the test efficiency by more than 3 times, greatly improve the validity of the test data, avoid repeated tests, reduce the waste of resources caused by repeated tests, and reduce the use cost of the test machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the cooling device of the present invention.

[0021] Figure 2 The schematic diagram of the cooling device structure of the present invention is shown in FIG. Figure 1 left view of the ).

[0022] Figure 3 It is a schematic diagram of the cooling ring structure of the cooling device of the present invention.

[0023] Figure 4 It is a schematic diagram of the rotating shaft, baffles and exhaust holes of the cooling device of the present invention.

[0024] Among them: 100-support component; 101-mounting hole; 102-air inlet; 103-main pipeline; 200-cooling ring; 201-semi-annular structure; 202-hollow shaft; 203-connecting part; 204-exhaust hole; 205-columnar tube; 206-blocking piece. DETAILED DESCRIPTION

[0025] In order to further understand the present invention, the present invention is described below in conjunction with examples, but the examples are only for further elaboration of the features and advantages of the present invention, rather than for limiting the claims of the present invention.

[0026] The present invention provides a sample cooling device for room temperature fatigue test, the structure of which is as follows: Figure 1-4 The cooling device includes three parts: a compressor, a support component 100 and a cooling ring 200; the compressor is used to provide cooling source compressed air, which is transported to the cooling ring 200 through the support component 100 and then sprayed onto the surface of the fatigue specimen through the exhaust holes 204 provided on the cooling ring, thereby achieving cooling of the specimen to be tested; the specific structure of each part is described as follows:

[0027] like Figure 1 As shown, the support component is a cylindrical structure, one end of which is provided with a mounting hole 101 for connecting to the fatigue testing machine; an air inlet 102 ( Figure 2 ), four air outlets are provided at the end of the support component away from the mounting hole, and an air inlet pipe is provided inside the support component; the air inlet pipe includes a main pipe 103 and four branch pipes branched from the main pipe, the air inlet is connected to the main pipe 103 of the air inlet pipe, and the four branch pipes are respectively connected to the four air outlets.

[0028] like Figure 3 As shown, the cooling ring 200 is assembled from four hollow cooling bodies of the same structure, wherein the hollow cooling body includes a semi-annular structure 201 and a connecting portion 203, and three hollow shafts 202 are arranged on the semi-annular structure; one free end of the semi-annular structure is closed, and the other free end is connected to the connecting portion, and a columnar tube 205 is arranged on the connecting portion; the columnar tube 205 and the three hollow shafts 202 are all arranged on the same side surface of the hollow cooling body.

[0029] The four hollow cooling bodies of the cooling ring with the same structure are assembled in pairs, specifically: the semi-annular structures of the two hollow cooling bodies are placed opposite to each other to form a circular ring, and the cylindrical tubes on the two hollow cooling bodies are respectively extended into the air outlets at the ends of the supporting part, and a sealing ring is provided in the air outlet to facilitate the formation of a sealing structure after the cylindrical tube is extended into the air outlet; the semi-annular structure can rotate along the cylindrical tube extended into the supporting part. After the semi-annular structures of the other two hollow cooling bodies are placed opposite to each other to form a circular ring, the hollow shafts on the two circular structures formed are connected one by one (the docking ends are set to a structure that can be plugged into each other), and the cylindrical tubes on the other two hollow cooling bodies are also extended into the air outlet at the end of the supporting part.

[0030] like Figure 4 As shown, the hollow shaft 202 is provided with a longitudinal row of exhaust holes 204, and a rotatable baffle 206 is also mounted on the hollow shaft. The rotation of the baffle can control whether each hollow shaft discharges gas, thereby regulating the discharge amount and discharge position of the gas discharged from the entire device.

[0031] The compressed air generated by the compressor is input into the cooling ring through the air inlet, the air inlet main pipe, the air inlet branch pipe and the air outlet in sequence, and then discharged from the hollow shaft and the exhaust hole on the cooling ring in sequence.

[0032] The support component and the cooling ring are made of polymer resin 3D printing.

[0033] The air compressor is provided with a pressure regulating valve, which can control the pressure of the provided compressed air.

[0034] The use process of the room temperature fatigue test sample cooling device of the present invention is as follows:

[0035] (1) Process the support part and cooling ring according to the drawing requirements;

[0036] (2) Assemble the cooling ring and the supporting part and install them on the fatigue testing machine.

[0037] (3) Connect the air compressor to the air inlet of the support part through a pipeline.

[0038] (4) Rotate the baffle on the cooling ring to expose the exhaust hole on the hollow rotating shaft for the required exhaust gas. Install the fatigue specimen with measured dimensions onto the testing machine according to the test steps. Adjust the rotation angle of the baffle on the cooling ring and the position of the exhaust port according to the shape and size of the specimen so that the exhaust port is located exactly in the working section of the specimen.

[0039] (5) Set the fatigue test parameters as required and start the fatigue test.

[0040] (6) Adjust the output pressure of compressed air according to the surface condition of the sample to achieve the optimal cooling effect.

[0041] During the sample installation process, the cooling device of the present invention must ensure that the sample working section cannot contact the cooling ring and the cooling ring is not subjected to force. The cooling device cannot be used in an environment containing corrosive media, and the operating temperature cannot exceed 100°C.

[0042] The fatigue specimen cooling device designed by the present invention has various cooling methods. The pressure regulating valve on the air compressor can adjust the pressure of the compressed air; the cooling ring can be adjusted at different angles through the columnar tube; the air outlet position on the cooling ring is provided with a baffle, and the baffle can be rotated to adjust the position and number of the air outlet. The cooling device can be adjusted in various ways according to different test materials and specimen sizes, so as to optimize the cooling method.

[0043] The cooling device of the present invention is detachable, and the cooling ring can be removed by rotating the cylindrical tube when loading and unloading the sample, thereby increasing the operating space. At the same time, the cooling ring is connected to the supporting part in the form of plug-in, which is easy to replace. More can be processed as spare parts. When the cooling ring is damaged during use, the spare parts can be directly and quickly replaced to continue the test, which greatly improves the test efficiency and also reduces the maintenance cost of the experimental equipment.

[0044] The sample cooling device provided by the present invention is used in conjunction with a fatigue testing machine during room temperature fatigue testing. The cooling device can effectively use compressed air to evenly cool the sample without affecting the material's organizational properties, thereby significantly increasing the test frequency, thereby accelerating the test cycle, and reducing test costs. The problem of uneven temperature on the sample surface can be effectively avoided by improving the cooling ring cooling structure, and the device can optimize sample cooling by adjusting the cooling ring angle and the air outlet distribution for different sample sizes, thereby ensuring the accuracy of the test and its wide application. The cooling device also has the characteristics of high reliability, simple operation, low cost, and convenient maintenance.

Claims

1. A sample cooling device for room temperature fatigue test, characterized in that: The cooling device comprises an air compressor, a supporting component and a cooling ring; the air compressor is used to provide compressed air as a cooling source, the compressed air is transported to the cooling ring through the supporting component, and then sprayed onto the surface of the fatigue specimen through the exhaust holes provided on the cooling ring, thereby achieving cooling of the specimen to be tested; The support component is a cylindrical structure, and a mounting hole is provided at one end for connecting to the fatigue testing machine; an air inlet is also provided on the side wall of the support component close to the mounting hole, and the air inlet is connected to the air inlet pipe in the support component, and the air inlet pipe is connected to the inside of the cooling ring; The other end of the support component is provided with four air outlets, the air inlet pipe includes a main pipe and four branch pipes branched from the main pipe, and the four branch pipes are respectively connected to the four air outlets; the compressed air generated by the compressor is sequentially input into the cooling ring through the air inlet I, the air inlet pipe main pipe, the air inlet pipe branch pipe and the air outlet; The cooling ring is assembled from four hollow cooling bodies of the same structure, wherein the hollow cooling body includes a semi-annular structure and a connecting portion, and three hollow shafts are arranged on the semi-annular structure; one free end of the semi-annular structure is closed, and the other free end is provided with a connecting portion, and a columnar tube is arranged on the connecting portion; the columnar tube and the three hollow shafts are all arranged on the same side surface of the hollow cooling body.

2. The sample cooling device for room temperature fatigue test according to claim 1, characterized in that: The four hollow cooling bodies of the cooling ring with the same structure are assembled in pairs, specifically: the semi-annular structures of the two hollow cooling bodies are placed opposite to each other to form a circular shape, and the cylindrical tubes on the two hollow cooling bodies are respectively extended into the air outlets at the ends of the supporting components, and a sealing ring is provided in the air outlet to facilitate the formation of a sealing structure after the cylindrical tube is extended into the air outlet; the semi-annular structure can rotate along the cylindrical tube extended into the supporting component; after the semi-annular structures of the other two hollow cooling bodies are placed opposite to each other to form a circular shape, the hollow shafts on the two circular structures formed are connected one by one, and the cylindrical tubes on the other two hollow cooling bodies are also extended into the air outlet at the end of the supporting part.

3. The sample cooling device for room temperature fatigue test according to claim 1, characterized in that: The hollow shaft is provided with a longitudinal row of exhaust holes, and a rotatable baffle is also mounted on the hollow shaft. The rotation of the baffle can control whether each hollow shaft discharges gas, thereby regulating the discharge amount and discharge position of the gas discharged from the entire device.

4. The sample cooling device for room temperature fatigue test according to claim 1, characterized in that: The support component and the cooling ring are made of polymer resin 3D printing.

5. The sample cooling device for room temperature fatigue test according to claim 1, characterized in that: The air compressor is provided with a pressure regulating valve, which can control the pressure of the provided compressed air.

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