A turning jig for flat plate tensile test pieces

Abstract

The application discloses a turning processing clamp suitable for a flat plate tensile test piece, which comprises a connecting column used for being connected with a lathe main shaft; a fixed plate is fixedly connected with the front end surface of the connecting column, and the fixed plate, the lathe main shaft and the connecting column are coaxially arranged; at least one fixed groove for accommodating the flat plate tensile test piece is formed in the front end surface of the fixed plate, and the length direction of the fixed groove is arranged perpendicularly to the radial direction of the fixed plate; the fixed groove which is arranged perpendicularly to the radial direction of the fixed plate can realize tangential eccentric clamping of the flat plate tensile test piece, that is, the flat plate tensile test piece is made into an arc segment of a circular annular whole blade disc disc body, so that when turning is performed, the processing tool marks of the turning surface of the flat plate tensile test piece are closer to the processing tool marks of the whole blade disc disc body, and thus the accuracy of a later tensile test is improved.

Description

Technical Field

[0001] This invention belongs to the field of tensile test specimen processing technology, and particularly relates to a turning fixture suitable for flat tensile test specimens. Background Technology

[0002] In the field of aero-engine integral bladed disk manufacturing, the main machining process for the integral bladed disk body is turning. To better understand the performance of the integral bladed disk after turning, a tensile test piece (flat plate) made of the same material as the integral bladed disk is usually used to simulate the machining process. Finally, the performance of the tensile test piece is measured, which is equivalent to obtaining the performance of the integral bladed disk after turning.

[0003] Currently, lathes are commonly used for machining shaft parts, but rarely for machining flat parts. Moreover, when flat parts are machined by fixing their center position to the lathe axis using common lathe fixtures, the cutting tool marks are inconsistent with those of the actual disc body. This results in a significant difference between the tensile properties of the machined tensile test specimen and the tensile properties of the integral bladed disk body, leading to inaccurate test results. Summary of the Invention

[0004] The purpose of this invention is to provide a turning fixture suitable for flat plate tensile test specimens, which fixes the tensile test specimens and adjusts their machining marks so that the machining marks are closer to the machining marks of the integral bladed disk body.

[0005] The present invention adopts the following technical solution: a turning fixture suitable for flat tensile test specimens, including a connecting column for connecting with a lathe spindle;

[0006] A fixing plate is fixedly connected to the front end face of the connecting column, and the fixing plate, the vehicle-mounted main shaft and the connecting column are set coaxially;

[0007] At least one fixing groove for accommodating a flat tensile test specimen is provided on the front end face of the fixing plate. The length direction of the fixing groove is perpendicular to the radial direction of the fixing plate. The size of the fixing groove is the same as the size of the flat tensile test specimen, and the depth of the fixing groove is less than the thickness of the flat tensile test specimen after processing.

[0008] Furthermore, when there are multiple fixing slots, the multiple fixing slots are symmetrically arranged with respect to the center point of the fixing plate.

[0009] Furthermore, multiple fixed slots are connected end to end, and the shape they form is a regular polygon.

[0010] Furthermore, a blind hole communicating with the fixing groove is provided on the wall surface of the edge of the fixing groove, and the blind hole extends from the front end face of the fixing plate to the rear end face.

[0011] Furthermore, a fixing hole is provided on the fixing plate at the position corresponding to the fixing groove;

[0012] The fixing holes are symmetrically distributed at both ends of the fixing groove.

[0013] Furthermore, each fixing slot corresponds to at least four fixing holes.

[0014] Furthermore, the fixing plate is a circular plate.

[0015] Furthermore, the blind hole is located at the corner of the fixing groove.

[0016] Furthermore, the connecting column is a cylinder.

[0017] The beneficial effects of this invention are: by setting a fixing groove perpendicular to its radial direction on the fixing plate, this invention can achieve tangential eccentric clamping of the flat plate tensile test piece, that is, make the flat plate tensile test piece into an arc segment of the integral bladed disk body in the shape of a ring. In this way, when turning, it can ensure that the machining marks on the turning surface of the flat plate tensile test piece are closer to the machining marks of the integral bladed disk body, thereby improving the accuracy of the subsequent tensile test. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the processing state of a tensile test specimen in the prior art;

[0019] Figure 2 This is a schematic diagram of the tensile test specimen.

[0020] Figure 3 A schematic diagram of the tensile test specimen from another perspective;

[0021] Figure 4 This is a schematic diagram showing the machining process of the entire bladed disk body;

[0022] Figure 5 This is a schematic diagram of the structure of the front end face of the fixing plate in an embodiment of the present invention;

[0023] Figure 6 This is a schematic diagram of the structure of the rear end face of the fixing plate in an embodiment of the present invention;

[0024] Figure 7 This is a structural schematic diagram of the front end face of the fixing plate from another perspective in an embodiment of the present invention;

[0025] Figure 8 This is a diagram showing the state of a flat tensile test specimen mounted on a fixed plate in an embodiment of the present invention.

[0026] Figure 9 This is a diagram showing the state of multiple flat tensile test specimens mounted on a fixed plate in an embodiment of the present invention.

[0027] Figure 10This is a state diagram from another perspective when multiple flat tensile test specimens are mounted on the fixing plate in an embodiment of the present invention;

[0028] Figure 11 This is a schematic diagram of the shape of the second machining mark on the flat plate tensile test specimen obtained in an embodiment of the present invention.

[0029] Among them: 10. Fixing plate; 11. Fixing groove; 12. Blind hole; 13. Fixing hole;

[0030] 20. Connecting post;

[0031] 30. Flat plate tensile test specimen; 31. First through hole; 32. Tensile section; 33. Second through hole;

[0032] 40. Integral bladed disk body; 50. Cutting tools;

[0033] 100. Fixing device; 200. Second machining mark; 300. First machining mark; Detailed Implementation

[0034] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0035] The structure of the flat plate tensile test specimen 30 in this invention is as follows: Figure 2 and Figure 3 As shown, it is a flat, elongated strip with a uniform thickness. The middle section is a tensile section 32, and both ends are fixed sections. The width of the tensile section 32 is smaller than the width of the fixed sections. A first through hole 31 and a second through hole 33 are provided on both fixed sections. The first through hole 31 / second through hole 33 on the two fixed sections are symmetrical with respect to the center of the flat tensile test piece 30. One side of the first through hole 31 / second through hole 33 is an enlarged hole, meaning the hole diameter gradually decreases from the surface inwards. When a certain depth is reached, the hole diameter is equal to the diameter of the through hole.

[0036] In existing technologies, such as Figure 1 As shown, when a flat plate tensile specimen 30 is used to simulate the turning of an integral bladed disk structure, it is fixed on a fixing device 100, and its center point is located on the axis of the lathe shaft. During the turning process, the flat plate tensile specimen 30 rotates with the fixing device 100 to turn its surface, and finally a second machining mark 300 is formed on the surface. The second machining mark 300 is concentric arc on the surface of the flat plate tensile specimen 30, and relative to the tensile direction of the flat plate tensile specimen 30, the second machining mark 300 is perpendicular to the tensile direction.

[0037] During the turning process of the integral bladed disk body 40, the machining diagram is as follows: Figure 4As shown, the integral bladed disk body is annular. When the integral bladed disk body 40 rotates with the lathe, the tool 50 moves radially along it. Finally, the third machining mark on the surface of the integral bladed disk body 40 is a number of concentric circular lines coaxial with the integral bladed disk body 40.

[0038] The force experienced by the integral bladed disk during its service life is low-cycle tangential tensile stress. This low-cycle tangential tensile stress is consistent with the direction of the third machining mark mentioned above, but inconsistent with the direction of the second machining mark 300 mentioned above. Therefore, if the existing method is used to process the flat plate tensile test piece 30 and conduct a tensile test to simulate the tensile properties of the integral bladed disk, the final test results will have a large error.

[0039] More specifically, the angle between the surface texture direction and the fatigue stress direction has a significant impact on fatigue life. In low-cycle tensile fatigue tests, fatigue cracks often originate at the bottom of the troughs in the surface texture and propagate perpendicular to the fatigue stress direction. When the surface texture direction is perpendicular to the fatigue stress direction, multiple fatigue cracks generated at the bottom of the surface texture troughs during the fatigue test are very likely to connect with each other along the texture to form fatigue line sources, accelerating fatigue failure. However, when the surface texture is parallel to the fatigue stress direction, although fatigue cracks are still most likely to start from the bottom of the surface texture troughs, fatigue cracks generated at different troughs are less likely to connect with each other, which can delay fatigue failure.

[0040] Therefore, it is very difficult for lathe technicians to improve the consistency between the machining method of the flat plate tensile test piece 30 and the machining process of the actual disk body part by turning it. It is necessary to improve the consistency of the parallel tool marks obtained by turning the flat plate tensile test piece 30 and the integral bladed disk body 40.

[0041] As a feasible method, the plate tensile test specimen 30 can be tangentially eccentrically clamped. However, existing turning equipment is difficult to meet the clamping conditions and cannot guarantee the machining requirements. In order to achieve the clamping conditions for the plate tensile test specimen 30, and at the same time maximize the consistency of its machining effect with the integral bladed disk body 40, and ensure that the subsequent tensile fatigue test results meet expectations, a tooling fixture suitable for turning plate tensile test specimens is needed to solve the existing problems.

[0042] This invention discloses a turning fixture suitable for flat tensile test specimens, such as... Figure 5 and Figure 6As shown, it includes a connecting column 20 for connecting to a lathe spindle; a fixing plate 10 is fixedly connected to the front end face of the connecting column 20, and the fixing plate 10, the lathe spindle, and the connecting column 20 are coaxially arranged; at least one fixing groove 11 for accommodating a flat tensile test piece 30 is provided on the front end face of the fixing plate 10, and the length direction of the fixing groove 11 is perpendicular to the radial direction of the fixing plate 10; wherein, the size of the fixing groove 11 is the same as the size of the flat tensile test piece 30, and the depth of the fixing groove 11 is less than the thickness of the flat tensile test piece 30 after processing.

[0043] The present invention enables tangential eccentric clamping of the flat plate tensile test specimen 30 by setting a fixing groove 11 perpendicular to its radial direction on the fixing plate 10. In other words, the flat plate tensile test specimen 30 becomes an arc segment of the integral bladed disk body that forms a ring. In this way, when turning, the machining marks on the turning surface of the flat plate tensile test specimen 30 can be more closely similar to the machining marks of the integral bladed disk body, thereby improving the accuracy of the subsequent tensile test.

[0044] In one embodiment, the connecting column 20 is preferably cylindrical, which facilitates clamping on the lathe. Moreover, the cylindrical structure ensures more even force distribution across all parts when rotating with the lathe spindle, reducing machining errors caused by imbalance. Similarly, the fixing plate 10 is a circular plate, and the thickness of the fixing plate 10 is equal at all locations.

[0045] As one implementation, when there are multiple fixing slots 11, the multiple fixing slots 11 are symmetrically arranged with respect to the center point of the fixing plate 10. This allows multiple flat tensile test specimens 30 to be processed at one time, saving testing time. Moreover, the symmetrical arrangement can make the overall weight balanced, thus reducing machining errors caused by imbalance.

[0046] More specifically, such as Figure 8 , Figure 9 and Figure 10 As shown, multiple fixed grooves 11 are connected end to end, forming a regular polygon. The difference between this design and the one described above is that in the former, the distances of each fixed groove 11 from the center point of the fixed plate 10 may differ. Therefore, although the tool marks during machining are similar to those of the overall bladed disk body 40, the different distances result in different tool mark curvatures on each plate tensile test piece 30, which can affect the test results. Therefore, the regular polygon design ensures that the distances of the multiple plate tensile test pieces 30 from the center point are equal, resulting in consistent tool mark curvatures on each plate tensile test piece 30 and minimizing the variation in measurement results.

[0047] In embodiments of the present invention, such as Figure 7As shown, a blind hole 12 communicating with the fixing groove 11 is provided on the wall surface of the edge of the fixing groove 11. The blind hole 12 extends from the front end face of the fixing plate 10 to the rear end face. Since the fixing groove 11 and the flat plate tensile test specimen 30 are the same size, when fixing the flat plate tensile test specimen 30, although bolts are also used, the two are interference fit. After the flat plate tensile test specimen 30 is processed, it is difficult to remove it from the fixing groove 11, and it is easy to damage the flat plate tensile test specimen 30. Therefore, the blind hole 12 is designed so that if necessary, other tools can be used to pry the flat plate tensile test specimen 13 into the blind hole 12 to facilitate its removal from the fixing groove 11.

[0048] Furthermore, the blind hole 12 is located at the corner of the fixing groove 11, which allows for better prying of the flat plate tensile test piece 13, so that one corner of it is subjected to force.

[0049] Regarding the fixing of the flat plate tensile test specimen 30, bolt connection is used in this embodiment of the invention. Specifically, fixing holes 13 are provided on the fixing plate 10 at positions corresponding to the fixing groove 11; the fixing holes 13 are symmetrically distributed at both ends of the fixing groove 11. Countersunk bolts are used to ensure a more stable connection.

[0050] Symmetrical distribution ensures balanced stress on the plate tensile test specimen 13. Furthermore, since the plate tensile test specimen 30 requires machining of two surfaces and uses flat-head bolts, enlarged holes need to be drilled at different locations on the two surfaces of the plate tensile test specimen 30. To facilitate connection, through holes are also drilled on the fixing plate 10 to better match the first through hole 31 (second through hole 33), meaning that each fixing groove 11 corresponds to at least four fixing holes.

[0051] In summary, this invention achieves a final flat plate tensile test specimen 30 with an eccentrically tangential clamping relative to the lathe axis, resulting in a surface on the end face of the flat plate tensile test specimen 30 that exhibits... Figure 11 The parallel arc-shaped second machining mark 200 shown is smaller as the eccentricity increases. The tool mark in the middle area of ​​the plate tensile test piece 30 is basically consistent with the parallel turning tool mark of the integral bladed disk body 40, and the cutting direction is consistent with the tensile stress direction. This achieves that the turning effect of the plate test piece is basically consistent with the turning effect of the real disk body, ensuring that the subsequent tensile fatigue test results meet expectations.

Claims

1. A turning fixture suitable for tensile testing of flat plates, characterized in that, Includes a connecting post (20) for connection with the lathe spindle; The front end face of the connecting column (20) is fixedly connected to a fixing plate (10), and the fixing plate (10), the vehicle-mounted main shaft and the connecting column (20) are coaxially arranged; The front end face of the fixing plate (10) is provided with at least one fixing groove (11) for accommodating the flat tensile test piece (30). The length direction of the fixing groove (11) is perpendicular to the radial direction of the fixing plate (10). The size of the fixing groove (11) is the same as the size of the flat tensile test piece (30), and the depth of the fixing groove (11) is less than the thickness of the flat tensile test piece (30) after processing.

2. The turning fixture for flat tensile test specimens as described in claim 1, characterized in that, When there are multiple fixing slots (11), the multiple fixing slots (11) are symmetrically arranged with respect to the center point of the fixing plate (10).

3. A turning fixture suitable for flat tensile test specimens as described in claim 2, characterized in that, The multiple fixed slots (11) are connected end to end, and the shape they form is a regular polygon.

4. A turning fixture suitable for flat tensile test specimens as described in claim 2 or 3, characterized in that, A blind hole (12) communicating with the fixing groove (11) is provided on the wall surface of the edge of the fixing groove (11), and the blind hole (12) extends from the front end face of the fixing plate (10) to the rear end face.

5. A turning fixture suitable for flat tensile test specimens as described in claim 4, characterized in that, A fixing hole (13) is provided on the fixing plate (10) at a position corresponding to the fixing groove (11); The fixing holes (13) are symmetrically distributed at both ends of the fixing groove (11).

6. A turning fixture suitable for flat tensile test specimens as described in claim 5, characterized in that, Each of the aforementioned fixing slots (11) has at least four fixing holes.

7. A turning fixture suitable for flat tensile test specimens as described in claim 5 or 6, characterized in that, The fixing plate (10) is a circular plate.

8. A turning fixture for flat tensile test specimens as described in claim 4, characterized in that, The blind hole (12) is located at the corner of the fixing groove (11).

9. A turning fixture for flat tensile test specimens as described in claim 8, characterized in that, The connecting column (20) is a cylinder.

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