Engine blade vibration fatigue test tool

Abstract

The utility model relates to the technical field of engine blade manufacturing, in particular to an engine blade vibration fatigue test tool, an upper clamping plate and a lower clamping plate are driven by a pressing device to clamp an engine blade, the upper clamping plate, the lower clamping plate and a connecting block are integrally formed, and through an arc transition cavity, the upper clamping plate and the lower clamping plate are integrally connected. The vibration fatigue of the clamping blocks in the vibration fatigue test process can be reduced, then the clamping stability of the engine blade is guaranteed, in the engine blade clamping process, stress generated in the relative movement process of the upper clamping plate and the lower clamping plate can be dispersed through the arc transition cavities, and the engine blade clamping stability is improved. Therefore, the stress concentration of the clamping block in the vibration fatigue test process is avoided.

Description

Technical Field

[0001] This utility model relates to the field of engine blade manufacturing technology, and in particular to a vibration fatigue testing fixture for engine blades. Background Technology

[0002] Currently, with the continuous improvement of material properties and social demands, various specifications of engine blades are emerging in an endless stream. Vibration is the most common load form during the service of engine blades. The fatigue failure caused by vibration must be considered in the blade strength design process in order to effectively improve its service safety and reliability. Conducting vibration fatigue tests on engine blades and obtaining performance data is not only a necessary assessment link in the engine blade research and development and production process, but also an important means of engine blade strength design and life prediction. The vibration fatigue test of engine blades requires a long test cycle (usually lasting several hours or even several days) and a high loading frequency (usually requiring hundreds to thousands of hertz), thus placing higher demands on the reliability of blade clamping.

[0003] To test the vibration fatigue performance of engine blades, those skilled in the art have developed an engine blade vibration fatigue testing fixture. The engine blade is clamped by a fixture and then connected to a vibration table for easy connection. However, due to the high-frequency vibration of the vibration table, the clamping stability of the fixture is reduced, so an engine blade vibration fatigue testing fixture with high clamping stability is needed. Utility Model Content

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a tooling for testing engine blade vibration fatigue.

[0005] This utility model is achieved through the following technical solution: a vibration fatigue testing fixture for engine blades, comprising a mounting base for connecting to a vibration table, a clamping block for clamping engine blades on the mounting base, a clamping device connected to the clamping block, the clamping block comprising an upper clamping plate and a lower clamping plate, a clamping opening for cooperating with the engine blades being formed between the upper and lower clamping plates, the upper and lower clamping plates being connected by a connecting block, a transverse arc transition cavity being provided on the connecting block, the opening of the arc transition cavity facing the clamping opening, the upper sidewall of the arc transition cavity being connected to the upper clamping plate, the lower sidewall of the arc transition cavity being connected to the lower clamping plate, and the upper clamping plate, the lower clamping plate and the connecting block being integrally formed.

[0006] Furthermore, both the upper and lower clamping plates are provided with clamping block tenons that mate with the tenons of the engine blades.

[0007] Furthermore, the mounting base includes a base for connecting to the vibration table, a gantry frame is provided at the upper end of the base, the clamping block is disposed inside the gantry frame, the lower end of the clamping block is supported by the base, and the clamping device includes a lifting pressure rod disposed on the gantry frame, the lifting pressure rod pushing the upper pressure plate downward during descent.

[0008] Furthermore, the lifting pressure rod is threadedly connected to the crossbeam of the gantry frame, and a pad is provided between the lifting pressure rod and the upper pressure plate, with the pad in contact with the surface of the upper pressure plate.

[0009] Furthermore, the lower end of the lifting rod is provided with a hemispherical top, and the upper surface of the pad is provided with an inner recessed circular groove that mates with the hemispherical top.

[0010] Furthermore, the clamping block is rectangular in shape, and the base is provided with engraved lines that cooperate with the clamping block and the pad.

[0011] The beneficial effects of this utility model are as follows: The engine blade vibration fatigue testing fixture clamps the engine blade through the upper and lower clamping plates driven by the clamping device. The upper and lower clamping plates and the connecting block are integrally formed, and the circular arc transition cavity can reduce the vibration fatigue of the clamping block itself during the vibration fatigue test, thereby ensuring the clamping stability of the engine blade. During the clamping process of the engine blade, the circular arc transition cavity can disperse the stress generated during the relative movement of the upper and lower clamping plates, thereby avoiding stress concentration of the clamping block itself during the vibration fatigue test. At the same time, the relative movement of the upper and lower clamping plates is a rotation around the axis of the circular arc transition cavity, with a large rotation angle, thereby giving the engine blade a larger contact area with the upper and lower clamping plates, and making the clamping more stable. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of Example 1;

[0013] Figure 2 This is a schematic diagram showing the connection between the clamping block and the gantry frame;

[0014] Figure 3 This is a schematic diagram of the lifting pressure bar structure;

[0015] Figure 4 This is a schematic diagram of the pad structure;

[0016] Figure 5 This is a schematic diagram of the end face of the clamping block;

[0017] Figure 6 This is a schematic diagram of the lifting pressure bar in Example 2.

[0018] The components include: 1. Vibration table; 2. Gantry frame; 3. Clamping block; 4. Pad plate; 5. Lifting pressure bar; 6. Engine blade; 101. Stepped mounting hole; 102. Horizontal engraving; 103. Upper clamping plate; 104. Longitudinal engraving; 105. Clamping block tenon; 106. Arc transition cavity; 107. Engine blade tenon; 108. Inner recessed circular groove; 109. Lower clamping plate; 110. Hexagonal socket; 111. Hemispherical top head; 112. Main rod; 113. Support seat; 114. Cam; 115. Handle. Detailed Implementation

[0019] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.

[0021] Example 1

[0022] like Figure 1-5As shown, a vibration fatigue testing fixture for engine blades includes a mounting base for connecting to a vibration table 1. A clamping block 3 for holding an engine blade 6 is mounted on the mounting base. The clamping block 3 is connected to a clamping device. Specifically, the mounting base includes a base for connecting to the vibration table 1. A gantry frame 2 is bolted to the upper end of the base. The mounting base is disc-shaped and made of stainless steel, enabling stable vibration transmission and high resistance to mechanical vibration. The gantry frame 2 is cut from stainless steel sheet. The clamping block 3 is installed inside the gantry frame 2. The clamping block 3 is rectangular in shape, cast from spring steel, and surface-ground. The clamping block 3 includes an upper clamping plate 103 and a lower clamping plate 109. A clamping opening for the engine blade 6 is formed between the upper clamping plate 103 and the lower clamping plate 109. The upper clamping plate 103 and the lower clamping plate 109 are connected by a connecting block. The connecting block has a transverse arc-shaped transition cavity 106. The opening of the arc-shaped transition cavity 106 faces the clamping opening. The diameter of the arc-shaped transition groove is the maximum width of the clamping opening. The arc transition groove is 0.5-1.0 times larger, which ensures that the arc transition groove has a sufficiently large size. The arc transition groove extends to both ends of the clamping block 3. The upper sidewall of the arc transition cavity 106 is connected to the upper clamping plate 103, and the lower sidewall of the arc transition cavity 106 is connected to the lower clamping plate 109. The upper clamping plate 103, the lower clamping plate 109 and the connecting block are integrally cast, which can reduce the vibration fatigue of the clamping block 3 itself during the vibration fatigue test, thereby ensuring the clamping stability of the engine blade 6. During the clamping of the engine blade 6, the arc transition cavity 106 can disperse the stress generated during the relative movement of the upper clamping plate 103 and the lower clamping plate 109, thereby avoiding stress concentration of the clamping block 3 itself during the vibration fatigue test. The upper clamping plate 103 and the lower clamping plate 109 are both integrally formed with clamping block tenons 105 that cooperate with the engine blade tenon 107, thereby ensuring the clamping stability of the engine blade 6. For different models of engine blade 6, different models of clamping blocks 3 are selected, thereby obtaining different models of clamping openings.

[0023] The lower end of the clamping block 3 is supported by the base. The clamping device includes a lifting rod 5 installed on the gantry 2. During the descent, the lifting rod 5 pushes the upper pressure plate downward. Specifically, the lifting rod 5 includes a main rod 112, which is threadedly connected to the crossbeam of the gantry 2. A threaded through hole is machined on the crossbeam of the gantry 2 to stably guide the main rod 112. An internal hexagonal hole 110 is machined at the upper end of the lifting rod 5, which can be turned to control the lifting rod 5's rise and fall. A pad 4 is installed between the lifting rod 5 and the upper pressure plate. The pad 4 is a stainless steel plate with a thickness of more than 8mm. The pad 4 is in contact with the upper pressure plate. The lifting rod 5 is integrally formed with a hemispherical top 111 at its lower end. The upper surface of the pad 4 is machined with an inner recessed circular groove 108 that matches the hemispherical top 111. During the clamping process of the clamping block 3 clamping the engine blade tenon 107, the upper pad 103 swings and deforms. Through the cooperation of the hemispherical top 111 and the inner recessed circular groove 108, the angle of force between the lifting rod 5 and the pad 4 can be adjusted, thereby ensuring the stability of clamping. It can also limit the cooperation position between the lifting rod 5 and the pad 4, improving assembly efficiency.

[0024] The base and the clamping block 3 have a flat surface, which facilitates the movement of the clamping block 3. The base is machined with engraved lines that cooperate with the clamping block 3 and the pad 4, including mutually perpendicular longitudinal engraved lines 104 and transverse engraved lines 102. The longitudinal engraved lines 104 and transverse engraved lines 102 are aligned with the axis of the main rod 112, which provides a reference during the installation of the clamping block 3 and the pad 4 and facilitates the positioning of the clamping block 3 and the pad 4.

[0025] The base is connected via stepped mounting holes 101 and countersunk bolts, thus preventing the bolts from coming loose and causing danger during the vibration fatigue test.

[0026] Example 2

[0027] like Figure 6 As shown, an engine blade vibration fatigue testing fixture differs from Embodiment 1 in that the main rod 112 is connected to the crossbeam of the gantry 2 with a tolerance fit. A support seat 113 is installed on the gantry 2, and a cam 114 is installed on the support seat 113 through a transverse rotating shaft. The cam 114 is connected to a handle 115, and the cam 114 is rotated by the handle 115, thereby driving the main rod 112 to push the upper pressure plate 103 downward. Compared with Embodiment 1, the operation is more stable and simpler, which is more convenient for batches of engine blades 6 of a single model. However, adjusting the clamping force is more troublesome, and it is easy to loosen during the vibration fatigue test.

[0028] During the testing process, we also tried using electric push rods, hydraulic cylinders and other drive structures to drive the main rod 112, which could adjust the clamping force, but it was greatly affected by vibration and could not be used for a long time.

[0029] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A vibration fatigue testing fixture for engine blades, comprising a mounting base for connecting to a vibration table, wherein the mounting base is provided with a clamping block for holding the engine blades, and the clamping block is connected to a clamping device, characterized in that, The clamping block includes an upper clamping plate and a lower clamping plate, and a clamping opening is formed between the upper clamping plate and the lower clamping plate to cooperate with the engine blade. The upper clamping plate and the lower clamping plate are connected by a connecting block. The connecting block is provided with a transverse arc transition cavity. The opening of the arc transition cavity faces the clamping opening. The upper sidewall of the arc transition cavity is connected to the upper clamping plate, and the lower sidewall of the arc transition cavity is connected to the lower clamping plate. The upper clamping plate, the lower clamping plate and the connecting block are integrally formed.

2. The engine blade vibration fatigue testing fixture according to claim 1, characterized in that, Both the upper and lower clamping plates are equipped with clamping tenons that mate with the tenons of the engine blades.

3. The engine blade vibration fatigue testing fixture according to claim 1, characterized in that, The mounting base includes a base for connecting to the vibration table. A gantry frame is provided at the upper end of the base. The clamping block is disposed inside the gantry frame. The lower end of the clamping block is supported by the base. The clamping device includes a lifting pressure rod disposed on the gantry frame. The lifting pressure rod pushes the upper pressure plate downward during descent.

4. The engine blade vibration fatigue testing fixture according to claim 3, characterized in that, The lifting pressure rod is threadedly connected to the crossbeam of the gantry frame, and a pad is provided between the lifting pressure rod and the upper pressure plate, with the pad in contact with the surface of the upper pressure plate.

5. The engine blade vibration fatigue testing fixture according to claim 4, characterized in that, The lower end of the lifting pressure rod is provided with a hemispherical top, and the upper surface of the pad plate is provided with an inner recessed circular groove that matches the hemispherical top.

6. The engine blade vibration fatigue testing fixture according to any one of claims 3-5, characterized in that, The clamping block is rectangular in shape, and the base has engraved lines that cooperate with the clamping block and the pad.

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