A multi-blade synchronous random equivalent loading fatigue test device

Abstract

The present invention relates to the technical field of strength test of aero-engine components, and particularly to a multi-blade synchronous random equivalent loading fatigue test device, which includes a tension screw, a blade positioning block, a horizontal top block, a vertical lower top block and a vertical upper top block. The bottom of the blade positioning block is connected to the moving coil of the vibration table. The installation groove includes a communicating tenon groove, a horizontal positioning groove and a vertical positioning groove. The tenon groove cooperates with the tenon head of the blade, and both the vertical lower top block and the vertical upper top block cooperate with the vertical positioning groove; both the vertical lower top block and the vertical upper top block abut against the horizontal top block; the tension screw is a bidirectional screw, and the vertical lower top block and the vertical upper top block are threadedly connected to different threaded segments of the tension screw. The present invention enables multiple blade test pieces to simultaneously feel the vibration load transmitted by the vibration tester, so that the load can accurately and truly act on the blades to be tested, so as to simulate the boundary conditions endured in the engine working state, and finally achieve the purpose of examining the fatigue strength of the blade test pieces.

Description

Technical Field

[0001] The present invention relates to the technical field of strength test of aero-engine components, and specifically to a multi-blade synchronous random equivalent loading fatigue test device. Background Art

[0002] Aero-engine blades are extremely important work components of aero-engines and play a very important role in the structure of aero-engines. When working, the blades are not only subjected to the action of high-temperature and high-pressure airflows, but also to the centrifugal force and vibration load brought by ultra-high rotational speeds, and very strict requirements are imposed on the materials and processing technologies of the blades. To verify the stability of the blade processing technology and the rationality of the structural design, it is necessary to conduct a vibration fatigue strength test on the blades to verify the strength reserve of the parts and provide a theoretical and experimental basis for the condition assessment and life evaluation of the parts.

[0003] Currently, due to the changes in the international situation and the increase in military training tasks, the demand for engines is continuously increasing, which also leads to a sharp increase in the demand for blades. With the improvement of the reliability requirements of engines, more stringent requirements are also put forward for the reliability and processing technology stability of engine components, and a specified number of blades need to be sampled for fatigue strength assessment for almost every machining batch. At the same time, the improvement of blade processing technology and the application of new materials and new processes all require fatigue strength verification tests on the blades.

[0004] Therefore, the test efficiency has become a bottleneck process restricting engine delivery. In order to meet the test requirements and improve the test efficiency, it is necessary to conduct fatigue tests on multiple blades simultaneously to complete the test tasks as quickly as possible with limited test equipment resources, so as to ensure the on-time delivery of the engines. Summary of the Invention

[0005] Aiming at the problem that it is not easy to conduct fatigue tests on multiple blades simultaneously in the prior art, the present invention provides a multi-blade synchronous random equivalent loading fatigue test device, so that when fatigue tests are conducted on aero-engine blades on a vibration tester, multi-blade narrowband random vibration loads can be applied.

[0006] The present invention is realized through the following technical solutions:

[0007] A multi-blade synchronous random equivalent loading fatigue test device, comprising a tensioning screw, a blade positioning block, a horizontal top block, a vertical lower top block and a vertical upper top block. The bottom of the blade positioning block is connected to the moving coil of the vibration table. The blade positioning block is evenly provided with a plurality of mounting grooves along the circumferential direction. The mounting groove includes a communicating mortise groove, a horizontal positioning groove and a vertical positioning groove. The mortise groove cooperates with the tenon of the blade. One end of the horizontal top block is located in the horizontal positioning groove and cooperates with the bottom of the blade tenon, and the other end extends out of the horizontal positioning groove and is located in the vertical positioning groove. The vertical lower top block and the vertical upper top block both cooperate with the vertical positioning groove. The vertical lower top block and the vertical upper top block are arranged on both sides of the extended horizontal top block, and the vertical lower top block and the vertical upper top block are both in contact with the horizontal top block. The tensioning screw is a two-way screw, and the vertical lower top block and the vertical upper top block are threadedly connected to different threaded sections of the tensioning screw.

[0008] Preferably, the blade positioning block is in an inverted T shape, and the bottom of the blade positioning block is provided with a disc structure, and the disc structure is connected to the moving coil of the vibration table.

[0009] Preferably, the cross-section of the mortise groove along the length axis is in a dovetail shape, the cross-section of the horizontal positioning groove along the length axis is in a rectangular shape, and the cross-section of the vertical positioning groove perpendicular to the length axis is in a trapezoidal shape.

[0010] Preferably, the mortise groove is coaxial with the horizontal positioning groove, and the length axis of the vertical positioning groove is perpendicular to the length axis of the horizontal positioning groove.

[0011] Preferably, the end of the horizontal top block that cooperates with the bottom of the blade tenon is in a flat surface structure.

[0012] Preferably, the end of the horizontal top block extending out of the vertical positioning groove is provided with two symmetric bevel structures.

[0013] Preferably, the vertical lower top block abuts against the horizontal top block in an inclined plane manner; the vertical upper top block abuts against the horizontal top block in an inclined plane manner.

[0014] Preferably, a spring is provided between the vertical lower top block and the vertical upper top block.

[0015] Preferably, the spring is sleeved on the outer wall of the tensioning screw.

[0016] Preferably, the vertical lower top block is provided with a first stepped through hole, the first stepped through hole includes a communicating first hole and a second hole, and the diameter of the first hole is larger than the diameter of the second hole. The vertical upper top block is provided with a second stepped through hole, the second stepped through hole includes a communicating third hole and a fourth hole, and the diameter of the third hole is larger than the diameter of the fourth hole. The first hole and the third hole cooperate to form a mounting hole, the spring is located in the mounting hole, and the first hole and the fourth hole are threadedly matched with the tensioning screw.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] A multi-blade synchronous random equivalent loading fatigue test device of the present invention connects multiple blade test pieces to a vibration tester, and holds the blades through a blade positioning block, a horizontal top block, a vertical lower top block, and a vertical upper top block under the action of a tension screw, so as to transfer the random vibration load of the vibration table to the four blades to be tested, and perform equivalent synchronous loading on the four blades, solving the problem that only a single blade can be tested under a sine fixed-frequency environment during the current blade fatigue strength assessment test. This device adopts an upper and lower combined V-shaped block tensioning and a horizontal top block tightening method to simulate the centrifugal force state of the blade under the engine working condition.

[0019] A multi-blade synchronous random equivalent loading fatigue test device of the present invention adopts an integrated structure, ensuring the rigidity of the structure and the symmetry of load transfer. This device and method can correctly and accurately apply the load, ensuring the authenticity and accuracy of the test results. This structure can realize the fatigue strength assessment of four blades simultaneously, and can be extended to more blade installation positions after continuous improvement of the structure, greatly improving the test efficiency.

[0020] A multi-blade synchronous random equivalent loading fatigue test device of the present invention has a compact structure and is easy to install and adjust. The vibration load of the tester can be transferred to the test piece through this device, and the narrowband random load generated by the vibration tester can act on multiple blade test pieces, so as to achieve the purpose of simultaneously conducting fatigue strength assessment tests on multiple blades. At the same time, it has strong versatility, can be used for the fatigue strength assessment of similar aero-engine blade test pieces, has a wide application range, and has strong engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic diagram of a multi-blade synchronous random equivalent loading fatigue test device of the present invention;

[0022] Figure 2 is a top view of a multi-blade synchronous random equivalent loading fatigue test device of the present invention;

[0023] Figure 3 is a cross-sectional view of a blade positioning block in a multi-blade synchronous random equivalent loading fatigue test device of the present invention;

[0024] Figure 4 is a top view of a blade positioning block in a multi-blade synchronous random equivalent loading fatigue test device of the present invention;

[0025] Figure 5It is the top view of the horizontal positioning block in a multi-blade synchronous random equivalent loading fatigue test device of the present invention;

[0026] Figure 6 It is the front view of the horizontal positioning block in a multi-blade synchronous random equivalent loading fatigue test device of the present invention;

[0027] Figure 7 It is the top view of the vertical lower top block in a multi-blade synchronous random equivalent loading fatigue test device of the present invention;

[0028] Figure 8 It is the cross-sectional view of the vertical lower top block in a multi-blade synchronous random equivalent loading fatigue test device of the present invention;

[0029] Figure 9 It is the top view of the vertical upper top block in a multi-blade synchronous random equivalent loading fatigue test device of the present invention;

[0030] Figure 10 It is the cross-sectional view of the vertical upper top block in a multi-blade synchronous random equivalent loading fatigue test device of the present invention.

[0031] In the figure, 1 is the blade positioning block; 2 is the horizontal top block; 21 is the planar structure; 22 is the inclined plane structure; 3 is the vertical lower top block; 4 is the vertical upper top block; 5 is the first stepped through hole; 51 is the first hole; 52 is the second hole; 6 is the second stepped through hole; 61 is the third hole; 62 is the fourth hole; 7 is the disc structure; I is the mortise groove; II is the horizontal positioning groove; III is the vertical positioning groove; a is the moving coil; b is the blade; c is the tensioning screw; d is the spring; e is the screw. Detailed implementation manners

[0032] The following further elaborates on the present invention in detail with specific embodiments, which is an explanation rather than a limitation of the present invention.

[0033] The present invention discloses a multi-blade synchronous random equivalent loading fatigue test device. Referring to Figure 1 、 2 , it includes a tensioning screw c, a blade positioning block 1, a horizontal top block 2, a vertical lower top block 3 and a vertical upper top block 4.

[0034] The blade positioning block 1 is in an inverted T shape, and a disc structure 7 is provided at the bottom of the blade positioning block 1. The disc structure 7 is connected to the moving coil a of the vibration table through a screw e.

[0035] A plurality of mounting grooves are uniformly arranged along the circumferential direction of the blade positioning block 1. Referring to Figure 3 、 4, the installation groove includes a communicating tenon groove I, a horizontal positioning groove II, and a vertical positioning groove III. The tenon groove I cooperates with the tenon of the blade b. In this embodiment, there are four installation grooves. The cross-section of the tenon groove I along the length axis is dovetail-shaped, the cross-section of the horizontal positioning groove II along the length axis is rectangular, and the cross-section of the vertical positioning groove III perpendicular to the length axis is trapezoidal. The tenon groove I and the horizontal positioning groove II are coaxial, and the length axis of the vertical positioning groove III is perpendicular to the length axis of the horizontal positioning groove II.

[0036] Referring to Figure 5 , 6 , one end of the horizontal top block 2 is located in the horizontal positioning groove II and cooperates with the bottom of the tenon of the blade b. Among them, the end of the horizontal top block 2 that cooperates with the bottom of the tenon of the blade b is a planar structure 21.

[0037] The vertical lower top block 3 and the vertical upper top block 4 are arranged on both sides of the horizontal top block 2 along the axis of the vertical positioning groove III. The vertical lower top block 3 and the vertical upper top block 4 are both in contact with the horizontal top block 2. The other end of the horizontal top block 2 extends out of the horizontal positioning groove II and is located in the vertical positioning groove III, and is provided with two symmetrical inclined plane structures 22, which cooperate with the vertical lower top block 3 and the vertical upper top block 4 respectively. The vertical upper top block 4 and the horizontal top block 2 are in contact with each other in an inclined plane manner, and the vertical lower top block 3 and the horizontal top block 2 are in contact with each other in an inclined plane manner.

[0038] The tensioning screw c is a two-way screw, and the vertical lower top block 3 and the vertical upper top block 4 are threadedly connected to different threaded sections of the tensioning screw c.

[0039] A spring d is provided between the vertical lower top block 3 and the vertical upper top block 4, and the spring d is sleeved on the outer wall of the tensioning screw c. Referring to Figure 7 , 8 , the vertical lower top block 3 is provided with a first stepped through hole 5, and the first stepped through hole 5 includes a communicating first hole 51 and a second hole 52. The diameter of the first hole 51 is larger than the diameter of the second hole 52; Referring to Figure 9 , 10 , the vertical upper top block 4 is provided with a second stepped through hole 6, and the second stepped through hole 6 includes a communicating third hole 61 and a fourth hole 62. The diameter of the third hole 61 is larger than the diameter of the fourth hole 62. The first hole 51 and the third hole 61 cooperate to form an installation hole, the spring d is located in the installation hole, and the first hole 51 and the fourth hole 62 are threadedly engaged with the tensioning screw c.

[0040] The implementation principle of a multi-blade synchronous random equivalent loading fatigue test device of the present invention is:

[0041] Before the test, fix the blade positioning block 1 on the moving coil a of the vibration table with eight screws e. Place the horizontal top block 2 in the horizontal positioning groove (Ⅱ) through the bottom surface of the mortise groove I. Place the vertical lower top block 3 at the bottom of the vertical positioning groove Ⅲ. Place the spring d in the third step through hole of the vertical lower top block 3. Place the vertical upper top block 4 in the upper part of the vertical positioning groove Ⅲ, and install the spring d into the fourth step through hole of the vertical upper top block 4. Pass the tensioning screw c through the step hole of the vertical upper top block 4 and cooperate with the threaded hole on the vertical lower top block 3.

[0042] During the test, install the tenon of the blade b in the mortise groove I of the blade positioning block 1. Use a torque-limiting wrench to rotate the tensioning screw c so that the vertical lower top block 3 moves upward along direction ②, and the vertical upper top block 4 moves downward along direction ③. Under the action of the inclined plane at the upper right corner of the vertical lower top block 3 and the inclined plane at the lower right corner of the vertical upper top block 4, the horizontal top block 2 moves along direction ①, and finally presses tightly against the tenon of the blade b to make the blade b reach a rigid holding state.

[0043] After the test is completed, loosen the tensioning screw c. The vertical upper top block 4 moves upward under the action of the spring d, thereby releasing the thrust on the horizontal top block 2, and the blade b is in a relaxed state and can be easily taken out. This device is a symmetric structure with four workstations, and the clamping process for each workstation is the same before the test. After ensuring that the blades b at all workstations are firmly clamped, finally turn on the vibration table to apply a narrowband random vibration load to the blades b to achieve the fatigue strength assessment of multiple blades b simultaneously.

[0044] A multi-blade synchronous random equivalent loading fatigue test device of the present invention enables multiple blade b test pieces to simultaneously feel the vibration load transmitted by the vibration tester, so that the load can accurately and truly act on the blades b to be tested, to simulate the boundary conditions endured in the engine working state, and finally achieve the purpose of assessing the fatigue strength of the blade b test pieces.

[0045] The above are only the preferred embodiments of the present invention, and are not used to limit the technical solutions of the present invention in any way. Those skilled in the art should understand that without departing from the spirit and principle of the present invention, the technical solutions can be modified and replaced simply in several aspects, and these modifications and replacements also fall within the protection scope covered by the claims.

Claims

1. A multi-blade synchronous random equivalent loading fatigue test device, characterized in that It includes a tensioning screw (c), a blade positioning block (1), a horizontal top block (2), a vertical lower top block (3) and a vertical upper top block (4). The bottom of the blade positioning block (1) is connected to the moving coil (a) of the vibrating table. The blade positioning block (1) is evenly provided with a plurality of mounting grooves along the circumferential direction. The mounting groove includes a communicating mortise groove (I), a horizontal positioning groove (II) and a vertical positioning groove (III). The mortise groove (I) is matched with the tenon of the blade (b). One end of the horizontal top block (2) is located in the horizontal positioning groove (II) and is matched with the bottom of the tenon of the blade (b), and the other end extends out of the horizontal positioning groove (II) and is located in the vertical positioning groove (III); the vertical lower top block (3) and the vertical upper top block (4) are both matched with the vertical positioning groove (III); the vertical lower top block (3) and the vertical upper top block (4) are arranged on both sides of the extended horizontal top block (2), and the vertical lower top block (3) and the vertical upper top block (4) are both in contact with the horizontal top block (2); the tensioning screw (c) is a two-way screw, and the vertical lower top block (3) and the vertical upper top block (4) are threadedly connected to different threaded sections of the tensioning screw (c).

2. The multi-blade synchronous random equivalent loading fatigue test device according to claim 1, wherein The blade positioning block (1) is in an inverted T shape, and the bottom of the blade positioning block (1) is provided with a disc structure (7), and the disc structure (7) is connected to the moving coil (a) of the vibrating table.

3. The multi-blade synchronous random equivalent loading fatigue test device according to claim 1, characterized in that The cross-section of the mortise groove (I) along the length axis is in a dovetail shape, the cross-section of the horizontal positioning groove (II) along the length axis is in a rectangular shape, and the cross-section of the vertical positioning groove (III) perpendicular to the length axis is in a trapezoidal shape.

4. The multi-blade synchronous random equivalent loading fatigue test device according to claim 1, characterized in that The mortise groove (I) is coaxial with the horizontal positioning groove (II), and the length axis of the vertical positioning groove (III) is perpendicular to the length axis of the horizontal positioning groove (II).

5. The multi-blade synchronous random equivalent loading fatigue test device according to claim 1, wherein, One end of the horizontal top block (2) that is matched with the bottom of the tenon of the blade (b) is a plane structure (21).

6. The multi-blade synchronous random equivalent loading fatigue test device according to claim 1, characterized in that One end of the horizontal top block (2) extending out of the vertical positioning groove (III) is provided with two symmetrical inclined plane structures (22).

7. The multi-blade synchronous random equivalent loading fatigue test device according to claim 6, wherein The vertical lower top block (3) and the horizontal top block (2) are in contact with each other in an inclined plane manner; the vertical upper top block (4) and the horizontal top block (2) are in contact with each other in an inclined plane manner.

8. The multi-blade synchronous random equivalent loading fatigue test device according to claim 1, wherein A spring (d) is provided between the vertical lower top block (3) and the vertical upper top block (4).

9. The multi-blade synchronous random equivalent loading fatigue test device according to claim 8, characterized in that, The spring (d) is sleeved on the outer wall of the tensioning screw (c).

10. The multi-blade synchronous random equivalent loading fatigue test device according to claim 9, characterized in that, The vertical lower top block (3) is provided with a first stepped through hole, and the first stepped through hole includes a communicating first hole (51) and a second hole (52), and the diameter of the first hole (51) is larger than the diameter of the second hole (52); the vertical upper top block (4) is provided with a second stepped through hole, and the second stepped through hole includes a communicating third hole (61) and a fourth hole (62), and the diameter of the third hole (61) is larger than the diameter of the fourth hole (62). The first hole (51) and the third hole (61) cooperate to form a mounting hole, the spring (d) is located in the mounting hole, and the first hole (51) and the fourth hole (62) are threadedly matched with the tensioning screw (c).

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