Test piece displacement limiting device

Abstract

The invention belongs to the field of aircraft structure fatigue tests, and particularly relates to a test piece displacement limiting device which comprises a test piece, a limiting device, a limiting switch and a limiting support. The limiting bracket is fixed on a supporting, loading or checking rack which is not changed relative to a test piece in position, the limiting device is adhered to the surface of the test piece, and the limiting switch is fixedly connected to the limiting bracket and is rotationally connected with the limiting device. The displacement of the test piece in any direction can be limited, and damage or destruction caused by excessive local deformation of the test piece structure is avoided; for the follow-up loading test, the relative displacement between the test piece and the loading structure can be limited, and the relative position between the test piece and the loading structure is kept unchanged; the limit switch bracket can ensure that the position of the limit switch can be adjusted in any direction, so that mounting and processing errors can be eliminated; the device is simple in structure and simple in manufacturing and mounting process.

Description

Technical Field

[0001] The present application belongs to the field of aircraft structure fatigue testing, and in particular relates to a test piece displacement limiting device. Background Art

[0002] In the fatigue test of aircraft structure, in order to simulate the actual loading condition of aircraft structure, it is necessary to apply a load spectrum whose load size and direction change periodically or irregularly with time. Under the action of fatigue load, the structure of the test piece will be displaced. In order to avoid abnormalities during the fatigue test, which may cause the test piece to be damaged due to excessive displacement of the structure, it is necessary to install a displacement limiting device for the test piece. The displacement limiting device currently used is a contact limit switch, which is characterized in that when the displacement change of the test piece reaches a certain value and touches the contact of the limit switch, the protection is triggered and the test is suspended to avoid damage or destruction of the test piece. The disadvantage is that it can only limit the displacement of the test piece in one direction, which meets the test safety protection requirements in most fatigue tests. However, for some special tests, such as flap fatigue test, dynamic loading is required during the test, that is, the relative position of the test piece and the loading device needs to be kept unchanged during the deflection of the flap. At this time, it is necessary to limit the displacement of the test piece in any direction, and the existing method has obvious shortcomings.

[0003] Therefore, how to limit the displacement of the test piece in any direction during the test is a problem that needs to be solved. Summary of the invention

[0004] The purpose of the present application is to provide a test piece displacement limiting device to solve the problem in the prior art that it is difficult to limit the displacement of the test piece in any direction.

[0005] The technical solution of the present application is: a test piece displacement limiting device, including a test piece, a limit device, a limit switch and a limit bracket; the limit bracket is fixed on a support, loading or inspection bench whose relative position with the test piece remains unchanged, the limit device is adhered to the surface of the test piece, the limit switch is fixedly connected to the limit bracket and the limit switch is rotatably connected to the limit device, and when position adjustment is required, the limit bracket can rotate along the connection position between the limit switch and the limit device.

[0006] Preferably, the limit device includes a fixed plate, a bent rod and a circular ring. The fixed plate is a rectangular structure and is adhered to the surface of the test piece. The two ends of the bent rod are respectively integrally connected to the fixed plate and the circular ring. The middle position of the circular ring is rotatably connected to the contacts of the limit switch.

[0007] Preferably, the limit bracket includes a column and a T-block, one end of the T-block is bolted to the side wall of the column, the interior and end of the T-block are hollow structures, the top of the T-block is provided with a flange, and the limit switch is bolted to the flange of the T-block.

[0008] Preferably, the column is a hollow structure and a waist-shaped groove is opened on the side wall. The bolt head between the T-block and the column is inserted into the interior of the column and fixed on the T-block by a nut.

[0009] The test piece displacement limiting device of the present application has the following advantages:

[0010] 1) It can limit the displacement of the test piece in any direction to avoid excessive local deformation of the test piece structure, resulting in damage or destruction;

[0011] 2) For dynamic loading tests, the relative displacement between the test piece and the loading structure can be limited to ensure that the relative position between the two remains unchanged;

[0012] 3) The limit switch bracket can ensure that the limit switch position can be adjusted in any direction, which can eliminate installation and processing errors;

[0013] 4) The device has a simple structure, and the manufacturing and installation process is simple;

[0014] 5) It is universal and can be used in all fatigue tests. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solution provided by the present application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present application.

[0016] Figure 1 This is a schematic diagram of the overall structure of this application;

[0017] Figure 2 This is a schematic diagram of the structure of the limit device of this application;

[0018] Figure 3 This is a schematic diagram of the limiting bracket structure of this application.

[0019] 1. Test piece; 2. Limit device; 3. Limit switch; 4. Limit bracket; 5. Fixing plate; 6. Bend rod; 7. Ring; 8. Column; 9. T-block. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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 creative work are within the scope of protection of the present invention.

[0021] A test piece displacement limiting device, such as Figure 1As shown, it includes a test piece 1, a limit device 2, a limit switch 3 and a limit bracket 4. The limit bracket 4 is fixed on a support, loading or inspection stand whose relative position with the test piece 1 remains unchanged, the limit device 2 is pasted on the surface of the test piece 1, the limit switch 3 is fixedly connected to the limit bracket 4, and the limit switch 3 is rotatably connected to the limit device 2. When position adjustment is required, the limit bracket 4 can be rotated along the connection position between the limit switch 3 and the limit device 2, so as to achieve adjustment in any direction of 360° circumferentially, and ensure that the relative position of the limit switch 3 and the limit device 2 is appropriate.

[0022] The working principle is as follows: During the fatigue test, when the displacement change of the test piece 1 in any direction (excluding the axial direction of the ring 7 of the limit device 2) reaches a certain value, the ring 7 at the end of the limit device 2 touches the contact of the limit switch 3, triggering the protection, and the test is suspended to avoid damage or destruction of the test piece 1; when the displacement change of the test piece 1 in the axial direction of the ring 7 of the limit device 2 reaches a certain value, the structural surface of the test piece 1 touches the contact of the limit switch 3, triggering the protection test to be suspended, and avoiding damage or destruction of the test piece 1.

[0023] like Figure 2 As shown, preferably, the limit device 2 includes a fixed plate 5, a bent rod 6 and a ring 7. The fixed plate 5 is a rectangular structure and is adhered to the surface of the test piece 1. The two ends of the bent rod 6 are integrally connected to the fixed plate 5 and the ring 7 respectively. The middle position of the ring 7 is rotatably connected to the contact of the limit switch 3, thereby realizing support for the limit bracket 4 to be adjusted in any direction.

[0024] Preferably, the limit bracket 4 includes a column 8 and a T-block 9, one end of the T-block 9 is bolted to the side wall of the column 8, the interior and end of the T-block 9 are hollow structures, the top of the T-block 9 is provided with a flange, and the limit switch 3 is bolted to the flange of the T-block 9 to ensure stable fixation.

[0025] like Figure 3 As shown, preferably, the column 8 is a hollow structure and a waist-shaped groove is opened on the side wall. The bolt head between the T-block 9 and the column 8 is inserted into the column 8 and fixed on the T-block 9 by a nut. Loosen the nut, the bolt can slide along the length direction of the column 8, so that the upper and lower positions of the T-block 9 and the limit switch 3 can be adjusted. After moving to a suitable position, tighten the nut, making the installation more flexible.

[0026] Through the above design, this application has the following advantages:

[0027] 1) It can limit the displacement of the test piece in any direction to avoid excessive local deformation of the test piece structure, resulting in damage or destruction;

[0028] 2) For dynamic loading tests, the relative displacement between the test piece and the loading structure can be limited to ensure that the relative position between the two remains unchanged;

[0029] 3) The limit switch bracket can ensure that the limit switch position can be adjusted in any direction, which can eliminate installation and processing errors;

[0030] 4) The device has a simple structure, and the manufacturing and installation process is simple;

[0031] 5) It is universal and can be used in all fatigue tests.

[0032] Finally, it should be noted that: the drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0033] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A test piece displacement limiting device, characterized in that: The invention comprises a test piece (1), a limit device (2), a limit switch (3) and a limit bracket (4); the limit bracket (4) is fixed on a support, loading or inspection stand whose relative position to the test piece (1) remains unchanged; the limit device (2) is adhered to the surface of the test piece (1); the limit switch (3) is fixedly connected to the limit bracket (4) and the limit switch (3) is rotatably connected to the limit device (2); when position adjustment is required, the limit bracket (4) can be rotated along the connection position between the limit switch (3) and the limit device (2).

2. The test piece displacement limiting device according to claim 1, characterized in that: The limit device (2) comprises a fixed plate (5), a bent rod (6) and a circular ring (7); the fixed plate (5) is a rectangular structure and is adhered to the surface of the test piece (1); the two ends of the bent rod (6) are respectively integrally connected to the fixed plate (5) and the circular ring (7); the middle position of the circular ring (7) is rotatably connected to the contact of the limit switch (3).

3. The test piece displacement limiting device according to claim 1, characterized in that: The limit bracket (4) comprises a column (8) and a T-shaped block (9), one end of the T-shaped block (9) is bolted to the side wall of the column (8), the interior and the end of the T-shaped block (9) are both hollow structures, the top of the T-shaped block (9) is provided with a flange, and the limit switch (3) is bolted to the flange of the T-shaped block (9).

4. The test piece displacement limiting device according to claim 3, characterized in that: The column (8) is a hollow structure and has a waist-shaped groove on its side wall. The bolt head between the T-block (9) and the column (8) is inserted into the column (8) and fixed on the T-block (9) by a nut.

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