A clamping system and clamping method for achieving high-precision control of thin-wall testing

Abstract

This invention discloses a clamping system for achieving high-precision control of thin-walled test, comprising: a thin-walled sample and a clamping assembly. The end of the thin-walled sample is connected to the clamping end of the testing machine through the clamping assembly. The clamping thickness of the clamping assembly is greater than the maximum dimension of the end of the thin-walled sample. Both sides of the end of the thin-walled sample are provided with locking portions. The clamping assembly is provided with a first groove for the end of the thin-walled sample to carry the locking portions into, and the end of the thin-walled sample is rotatably disposed within the first groove. A second groove is provided on the inner wall surface of the first groove, and a locking groove is provided on the inner wall surface of the second groove. The locking grooves of the clamping assemblies at both ends of the thin-walled sample are located on the same plane. When the locking portions at both ends of the thin-walled sample are engaged in the locking grooves, the entire thin-walled sample can be positioned on the same plane. Combined with the thicker clamping assembly and its resistance to deformation when clamped on the testing machine, high-precision control of the thin-walled sample is achieved, greatly improving the loading accuracy of the thin-walled sample.

Description

Technical Field

[0001] This invention relates to the field of mechanical property testing equipment, and in particular to a clamping system and clamping method for achieving high-precision control in thin-wall testing. Background Technology

[0002] With the continuous improvement of the thrust-to-weight ratio of aero engines, the service temperature of turbine blades is also increasing, and the internal structure of turbine blades is becoming increasingly complex. The use of film cooling systems can effectively reduce the surface temperature of the blades, but this blade structure requires the parts to have very thin walls, with the thinnest part even less than 0.5 mm. Studies have found that the mechanical properties of these thin-walled parts of turbine blades are usually lower than those of standard specimens. This performance deviation caused by cross-sectional dimensions is called the thin-wall effect. In order to accurately predict the performance and life of parts with thin-walled sections, people are paying more and more attention to the impact of the thin-wall effect. In recent years, many researchers have begun to prepare thin-walled mechanical property specimens of different thicknesses to study the thin-wall effect.

[0003] When a normal specimen is placed on a testing machine (such as a creep tester), it should be centered under no-stress conditions. Because thin-walled specimens have small wall thicknesses and are easily bent and twisted, their stress sensitivity is very high. Human error during installation and slight unevenness of the testing machine clamps and the specimen surface (which is difficult to observe with the naked eye) can cause the specimen to undergo unbalanced deformation under stress, resulting in the specimen being out of axis from the direction of the applied force. Especially for plate-shaped specimens, if any contact area with the tie rod deforms, it will cause the specimen to deflect and not be coaxial with the force, resulting in deformation of the specimen during mechanical property testing and affecting the accuracy of the test data.

[0004] For example, the invention patent with application number "201810314417.3" and title "A Tensile Testing Machine" discloses a tensile testing machine that fixes the specimen by means of upper and lower clamps. However, when dealing with thin-walled specimens, the thin-walled specimens are prone to deformation during clamping, resulting in inaccurate loading of the thin-walled specimens and affecting the accuracy of the final test.

[0005] The invention patent with application number "201510184070.1" and title "A Tensile Testing Machine for Blades" discloses a tensile testing machine. It has grooves on both the upper and lower clamps that match the specimen. When the specimen is connected to the groove, it can be positioned well. However, the upper clamps fix the specimen by pin. When assembling the pins, which are easily deformable thin-walled specimens, the contact position may be deformed, affecting the final test accuracy.

[0006] Therefore, there is an urgent need for a clamping system that can achieve high-precision control of thin-walled test, with high loading accuracy of thin-walled specimens and high accuracy of test data. Summary of the Invention

[0007] The purpose of this invention is to provide a clamping system and clamping method for achieving high-precision control of thin-walled test, in order to solve the problems existing in the prior art. By utilizing the thicker characteristics of the clamping component to replace the connection between the thin-walled sample and the clamping end of the testing machine, and cooperating with the clamping component to position the thin-walled sample, high-precision control of the loading of the thin-walled sample is achieved, improving the loading accuracy of the thin-walled sample, and thus improving the accuracy of the test data.

[0008] To achieve the above objectives, the present invention provides the following solution: The present invention provides a clamping system for achieving high-precision control of thin-walled test, including a thin-walled sample and a clamping assembly connected to the clamping end of a testing machine. The end of the thin-walled sample is connected to the clamping end of the testing machine through the clamping assembly. The clamped thickness of the clamping assembly is greater than the maximum dimension of the end of the thin-walled sample. At least one locking portion is provided on both sides of the end of the thin-walled sample. The clamping assembly is provided with a first groove into which the end of the thin-walled sample carries the locking portion. The end of the thin-walled sample is rotatably disposed in the first groove. At least one second groove is provided on the inner wall surface of the first groove for the locking portion to rotate. A locking groove matching the locking portion is provided on the inner wall surface of the second groove. The locking grooves in the clamping assembly at both ends of the thin-walled sample are located on the same plane.

[0009] Preferably, the axial cross-section of the second groove is a circle that matches the rotation path of the snap-fit ​​part, and the axis of the second groove coincides with the force direction of the testing machine.

[0010] Preferably, a rotational fit clearance is provided between the first groove and the end of the thin-walled sample, and between the second groove and the snap-fit ​​portion, to ensure normal rotation.

[0011] Preferably, the snap-fit ​​portion has a rectangular structure.

[0012] Preferably, the thickness of the snap-fit ​​portion is the same as the thickness of the thin-walled sample.

[0013] Preferably, the snap-fit ​​portion is integrally formed with the thin-walled sample.

[0014] Preferably, the clamping assembly is T-shaped, and the smaller end of the clamping assembly is provided with the first groove.

[0015] Preferably, the clamping assembly is made of ceramic or high-temperature alloy.

[0016] Preferably, the clamping assembly includes a first clamping block and a second clamping block. The lower surface of the first clamping block is connected to the upper surface of the second clamping block, and the lower surface of the first clamping block is provided with a first splicing groove, and the upper surface of the second clamping block is provided with a second splicing groove. After the first clamping block and the second clamping block are connected, the first splicing groove and the second splicing groove are spliced ​​together to form the first groove and the second groove.

[0017] The present invention also provides a clamping method for the clamping system described above for achieving high-precision control in thin-wall testing, comprising the following steps:

[0018] S1: Connect the clamping assembly to the clamping end of the testing machine, and insert both ends of the thin-walled sample into the first groove of the different clamping assemblies, and make the snap-fit ​​part correspond to the second groove;

[0019] S2: Control the thin-walled sample to rotate along its axial direction, and screw the locking part into the second groove;

[0020] S3: After controlling the thin-walled sample to rotate by a certain angle, make the snap-fit ​​part correspond to the snap-fit ​​groove, and adjust the upper clamping component upward so that the snap-fit ​​part snaps into the snap-fit ​​groove;

[0021] S4: Start the test. The testing machine uses the clamping assembly to test the mechanical properties of the thin-walled specimen.

[0022] The present invention achieves the following technical effects compared to the prior art:

[0023] 1. In this invention, the clamping thickness of the clamping assembly is greater than the maximum dimension of the thin-walled sample end. A thicker clamping assembly is used to replace the thin-walled sample. The thicker the clamping thickness, the less likely deformation will occur during clamping. Furthermore, during the installation of the thin-walled sample after installing the clamping assembly, since the clamping assembly is already held by the testing machine, its weight will not cause the thin-walled sample to bend or deform. Simply insert the end of the thin-walled sample into the first groove, align the locking part with the second groove, rotate the thin-walled sample so that the locking part corresponds to the locking groove, and then pull the thin-walled sample to engage the locking part into the locking groove. Because the thin-walled sample... The locking slots in the clamping components at both ends are located on the same plane. When the locking parts at both ends of the thin-walled specimen are engaged in the locking slots, the entire thin-walled specimen can be located on the same plane. At the same time, there is no rigid clamping between the clamping components and the thin-walled specimen, which avoids the deformation problem when the thin-walled specimen is connected to the clamping components. Combined with the characteristic that the clamping components are not easily deformed when clamped on the testing machine, the entire thin-walled specimen can be installed in the tensile area of ​​the testing machine without deformation. This achieves high-precision control of the thin-walled specimen, greatly improves the loading accuracy of the thin-walled specimen, and thus improves the accuracy of the test data.

[0024] 2. In this invention, the axial cross-section of the second groove is a circle that matches the rotation path of the snap-fit ​​part. When the thin-walled sample carrying the snap-fit ​​part enters the first groove, and the thin-walled sample rotates, causing the snap-fit ​​part to rotate in the second groove, the second groove can provide a limiting effect for the rotation of the snap-fit ​​part, ensuring that the snap-fit ​​part can be accurately snapped into the snap-fit ​​groove. Since the axis of the second groove coincides with the force direction of the testing machine, when the snap-fit ​​part is snapped into the snap-fit ​​groove, the axis of the thin-walled sample coincides with the force direction of the testing machine.

[0025] 3. In this invention, rotational fit gaps are provided between the first groove and the end of the thin-walled sample, and between the second groove and the snap-fit ​​part to ensure normal rotation. This can effectively prevent the thin-walled sample and the snap-fit ​​part from being damaged or bent during rotation, and further ensure the accurate loading of the thin-walled sample.

[0026] 4. In this invention, the clamping assembly is configured as a first clamping block and a second clamping block, so that when the part of the thin-walled sample located inside the clamping assembly breaks, the clamping assembly can be opened and the broken part inside can be quickly removed. Attached Figure Description

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a schematic diagram of the clamping system for achieving high-precision control in thin-wall testing according to the present invention;

[0029] Figure 2 This is a cross-sectional view of the clamping assembly of the present invention;

[0030] Figure 3 This is a schematic diagram of the structure of the first clamping block of the present invention;

[0031] Figure 4 This is a cross-sectional view of the clamping system for achieving high-precision control of thin-wall testing according to the present invention;

[0032] Figure 5 This is a schematic diagram of the structure of the thin-walled sample of the present invention;

[0033] The components include: 1. clamping assembly; 2. thin-walled sample; 3. snap-fit ​​part; 4. first groove; 5. second groove; 6. snap-fit ​​groove; 7. first clamping block; 8. second clamping block; and 9. connecting hole. Detailed Implementation

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0035] The purpose of this invention is to provide a clamping system and clamping method for achieving high-precision control of thin-walled test, in order to solve the problems existing in the prior art. By utilizing the thicker characteristics of the clamping component to replace the connection between the thin-walled sample and the clamping end of the testing machine, and in conjunction with the positioning of the thin-walled sample by the clamping component, high-precision control of the loading of the thin-walled sample is achieved, thereby improving the loading accuracy of the thin-walled sample and thus improving the accuracy of the test data.

[0036] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] Please refer to the following: Figures 1-5As shown, a clamping system for achieving high-precision control in thin-walled testing is provided, including a thin-walled specimen 2 and a clamping assembly 1 connected to the clamping end of a testing machine. The clamping end of the testing machine can be a conventional jaw. The end of the thin-walled specimen 2 is connected to the clamping end of the testing machine via the clamping assembly 1. The clamping thickness of the clamping assembly 1 is greater than the maximum dimension of the end of the thin-walled specimen 2. A thicker clamping assembly 1 is used instead of the thin-walled specimen 2. The thicker the clamping thickness, the less likely deformation will occur during clamping. Furthermore, during the process of installing the thin-walled specimen 2 after installing the clamping assembly 1, since the clamping assembly 1 is already clamped by the testing machine, its gravity will not cause the thin-walled specimen 2 to bend or deform. At least one locking part 3 is provided on both sides of the end of the thin-walled specimen 2. Parts 3 can be arranged symmetrically or staggered. The clamping assembly 1 is provided with a first groove 4 for the end of the thin-walled sample 2 carrying the locking part 3 to extend into. The cross-sectional shape of the first groove 4 can be rectangular, and the length of the rectangle is not less than the sum of the width of the end of the thin-walled sample 2 and the length of the locking parts 3 on both sides, to ensure that the end of the thin-walled sample 2 carrying the locking part 3 can extend into it. The width of the rectangle matches the width of the end of the thin-walled sample 2. Alternatively, the main body can be circular, but the circle needs to protrude outwards corresponding to the position of the locking part 3. The diameter of the circle matches the width of the end of the thin-walled sample 2, and the size of the protruding part matches the locking part 3. Or other shapes can be used to allow the end of the thin-walled sample 2 carrying the locking part 3 to extend into it. The end of the thin-walled sample 2 is rotatably positioned in the first groove 4. The specific rotation method is rotation around its own axis. At least one second groove 5 is provided on the inner wall of the first groove 4 for the locking part 3 to rotate. When the locking parts 3 on both sides of the thin-walled sample 2 are symmetrically arranged, the number of second grooves 5 is equal to the number of sets of symmetrical locking parts 3. When the locking parts 3 on both sides of the thin-walled sample 2 are misaligned, the number of second grooves 5 is equal to the sum of the number of locking parts 3 on both sides of the thin-walled sample 2. A locking groove 6 matching the locking part 3 is provided on the inner wall of the second groove 5. The locking grooves 6 in the clamping assemblies 1 at both ends of the thin-walled sample 2 are located on the same plane. Simply insert the end of the thin-walled sample 2 into the first groove 4, align the locking part 3 with the second groove 5, and then rotate the thin-walled sample 2 so that the locking part 3 corresponds to the locking groove 6. Then, pull the thin-walled sample 2 to engage the locking part 3 into the locking groove 6. Since the locking grooves 6 in the clamping components 1 at both ends of the thin-walled sample 2 are on the same plane, when the locking parts 3 at both ends of the thin-walled sample 2 are engaged into the locking grooves 6, the entire thin-walled sample 2 can be positioned on the same plane. At the same time, there is no rigid clamping between the clamping components 1 and the thin-walled sample 2, avoiding the deformation problem when the thin-walled sample 2 is connected to the clamping components 1. Combined with the characteristic that the clamping components 1 is not easily deformed when clamped on the testing machine, the entire thin-walled sample 2 can be installed in the tensile area of ​​the testing machine without deformation, that is, high-precision control of the thin-walled sample 2 is achieved, which greatly improves the loading accuracy of the thin-walled sample 2 and thus improves the accuracy of the test data.

[0038] The axial cross section of the second groove 5 is set to be a circle that matches the rotation path of the snap-fit ​​part 3. When the thin-walled sample 2 carries the snap-fit ​​part 3 into the first groove 4, and the thin-walled sample 2 rotates, causing the snap-fit ​​part 3 to rotate in the second groove 5, the second groove 5 can provide a limiting effect for the rotation of the snap-fit ​​part 3, ensuring that the snap-fit ​​part 3 can be accurately snapped into the snap-fit ​​groove 6. Since the axis of the second groove 5 coincides with the force direction of the testing machine, when the snap-fit ​​part 3 is snapped into the snap-fit ​​groove 6, the axis of the thin-walled sample 2 coincides with the force direction of the testing machine.

[0039] Rotational fit gaps can be provided between the first groove 4 and the end of the thin-walled sample 2, and between the second groove 5 and the snap-fit ​​part 3, to ensure normal rotation. This can effectively prevent the thin-walled sample 2 and the snap-fit ​​part 3 from being damaged or bent during rotation, and further ensure the accurate loading of the thin-walled sample 2. At the same time, the inner wall of the snap-fit ​​groove 6 away from the axis of the second groove 5 can be set to an outward inclined structure to ensure that the snap-fit ​​part 3 can accurately slide into the snap-fit ​​groove 6 to complete the positioning of the thin-walled sample 2 when there is a fit gap.

[0040] Since the snap-fit ​​part 3 is directly subjected to the tensile force transmitted by the clamping assembly 1 from the testing press, the snap-fit ​​part 3 has a rectangular structure, which increases the contact area between the snap-fit ​​part 3 and the snap-fit ​​groove 6, disperses stress, and improves the service life of the snap-fit ​​part 3.

[0041] To ensure uniform force transmission, the thickness of the snap-fit ​​part 3 is set to be the same as the thickness of the thin-walled sample 2.

[0042] The snap-fit ​​part 3 can be integrally set with the thin-walled sample 2, thereby improving the structural strength of the connection between the thin-walled sample 2 and the snap-fit ​​part 3 and reducing the probability of breakage at the connection.

[0043] To facilitate clamping by the clamping end of the testing machine, the clamping component 1 is T-shaped, and the smaller end of the clamping component 1 is provided with a first groove 4. When actually selecting the clamping end of the testing machine, the free end can be L-shaped, directly clamping the larger end of the clamping component 1. The stepped structure at the turning point between the larger end and the smaller end of the clamping component 1 can work with the L-shaped free end of the clamping end to improve the clamping effect of the testing machine on the clamping component 1.

[0044] Since some tensile tests need to be performed at high temperatures, clamping assembly 1 is made of high-temperature resistant materials such as ceramics or high-temperature alloys.

[0045] In this embodiment, two locking parts 3 are provided on both sides of the thin-walled specimen 2, and four locking parts 3 are provided at the ends of the thin-walled specimen 2. In this way, when subjected to actual tension, the eight locking parts 3 at both ends of the thin-walled specimen 2 can disperse the stress and reduce the probability of the thin-walled specimen 2 breaking at the connection between the locking parts 3 due to stress concentration. The specific number of locking parts 3 can be determined according to the predetermined tensile force, and the number of locking parts 3 increases with the increase of the predetermined tensile force.

[0046] To address the situation where the thin-walled sample 2 breaks within the clamping assembly 1, making it difficult to remove the broken portion, the clamping assembly 1 includes a first clamping block 7 and a second clamping block 8. The lower surface of the first clamping block 7 is connected to the upper surface of the second clamping block 8. Specifically, both the first clamping block 7 and the second clamping block 8 are provided with connecting holes 9, which are connected by pins or bolts. The lower surface of the first clamping block 7 is provided with a first splicing groove, and the upper surface of the second clamping block 8 is provided with a second splicing groove. After the first clamping block 7 and the second clamping block 8 are connected, the first splicing groove and the second splicing groove are spliced ​​to form a first groove 4 and a second groove 5. When the thin-walled sample 2 breaks within the clamping assembly 1, the clamping assembly 1 can be opened to quickly remove the broken portion.

[0047] In this embodiment, the first clamping block 7 and the second clamping block 8 are designed to have the same structure, which facilitates processing and production.

[0048] The present invention also provides a clamping method for the clamping system described above for achieving high-precision control in thin-wall testing, comprising the following steps:

[0049] S1: Connect the clamping assembly 1 to the clamping end of the testing machine, adjust the height of the upper clamping assembly 1 upwards, and place the thin-walled sample 2 between the upper and lower clamping assemblies 1. Control the upper clamping assembly 1 to move downwards, and insert both ends of the thin-walled sample 2 into the first groove 4 of the different clamping assemblies 1, and make the snap-fit ​​part 3 correspond to the second groove 5.

[0050] S2: Manual or machine control (when the rotation is controlled by machine, a rotation mechanism needs to be set at both the upper and lower clamping ends of the testing machine) The thin-walled specimen 2 rotates around its axis, and the snap-fit ​​part 3 is screwed into the second groove 5.

[0051] S3: After controlling the thin-walled sample 2 to rotate by a certain angle, the locking part 3 is aligned with the locking groove 6. The upper clamping component 1 is adjusted upward, and the locking parts 3 at both ends of the thin-walled sample 2 are locked into the corresponding locking grooves 6, thus completing the positioning of the thin-walled sample 2.

[0052] S4: Start the test. The testing machine uses clamping assembly 1 to test the mechanical properties of the thin-walled sample 2.

[0053] Any adaptive changes made according to actual needs are within the scope of protection of this invention.

[0054] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0055] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A clamping system for achieving high-precision control in thin-walled testing, characterized in that, The device includes a thin-walled specimen and a clamping assembly connected to the clamping end of a testing machine. The end of the thin-walled specimen is connected to the clamping end of the testing machine through the clamping assembly. The clamped thickness of the clamping assembly is greater than the maximum size of the end of the thin-walled specimen. At least one snap-fit ​​portion is provided on both sides of the end of the thin-walled specimen. The clamping assembly is provided with a first groove for the end of the thin-walled specimen to carry the snap-fit ​​portion into, and the end of the thin-walled specimen is rotatably disposed in the first groove. At least one second groove is provided on the inner wall surface of the first groove for the snap-fit ​​portion to rotate. A snap-fit ​​groove matching the snap-fit ​​portion is provided on the inner wall surface of the second groove. The snap-fit ​​grooves in the clamping assembly at both ends of the thin-walled specimen are located on the same plane. The axial cross section of the second groove is a circle that matches the rotation path of the snap-fit ​​part.

2. The clamping system for achieving high-precision control of thin-wall testing according to claim 1, characterized in that, The axis of the second groove coincides with the direction of force applied by the testing machine.

3. The clamping system for achieving high-precision control of thin-wall testing according to claim 2, characterized in that, A rotational fit clearance is provided between the first groove and the end of the thin-walled sample, and between the second groove and the snap-fit ​​part to ensure normal rotation.

4. The clamping system for achieving high-precision control of thin-wall testing according to claim 1, characterized in that, The snap-fit ​​part has a rectangular structure.

5. The clamping system for achieving high-precision control of thin-wall testing according to claim 4, characterized in that, The thickness of the snap-fit ​​portion is the same as the thickness of the thin-walled sample.

6. The clamping system for achieving high-precision control of thin-wall testing according to claim 5, characterized in that, The snap-fit ​​portion is integrally formed with the thin-walled sample.

7. The clamping system for achieving high-precision control of thin-wall testing according to claim 1, characterized in that, The clamping assembly is T-shaped, and the smaller end of the clamping assembly is provided with the first groove.

8. The clamping system for achieving high-precision control of thin-wall testing according to claim 7, characterized in that, The clamping assembly is made of ceramic or high-temperature alloy.

9. The clamping system for achieving high-precision control of thin-wall testing according to claim 7, characterized in that, The clamping assembly includes a first clamping block and a second clamping block. The lower surface of the first clamping block is connected to the upper surface of the second clamping block. The lower surface of the first clamping block is provided with a first splicing groove, and the upper surface of the second clamping block is provided with a second splicing groove. After the first clamping block and the second clamping block are connected, the first splicing groove and the second splicing groove are spliced ​​together to form the first groove and the second groove.

10. A clamping method for a clamping system for achieving high-precision control of thin-wall testing as described in any one of claims 1-9, characterized in that, Includes the following steps: S1: Connect the clamping assembly to the clamping end of the testing machine, and insert both ends of the thin-walled sample into the first groove of the different clamping assemblies, and make the snap-fit ​​part correspond to the second groove; S2: Control the thin-walled sample to rotate along its axial direction, and screw the locking part into the second groove; S3: After controlling the thin-walled sample to rotate by a certain angle, make the snap-fit ​​part correspond to the snap-fit ​​groove, and adjust the upper clamping component upward so that the snap-fit ​​part snaps into the snap-fit ​​groove; S4: Start the test. The testing machine uses the clamping assembly to test the mechanical properties of the thin-walled specimen.

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