Strip spring integral fatigue test fixture

Abstract

The present disclosure belongs to the field of nuclear power technology, and specifically relates to a strip spring overall fatigue test fixture. The present disclosure clamps the strip spring to be tested by using a bottom plate positioning plate and a pressure plate, and uses a pad and a test rod to press against the steel convex and spring piece of the strip spring, realistically simulating the real service constraint conditions of the simulated strip spring, and solving the problem of being unable to test and study the overall fatigue performance of the strip spring. Thus, the simulation and testing of the real working conditions of the spring can be realized, which provides important theoretical guidance and technical support for studying the fatigue performance of the strip spring, and has important scientific significance and engineering application value.

Description

Technical Field

[0001] The invention belongs to the technical field of nuclear power, and in particular relates to a strip spring integral fatigue test fixture. Background Art

[0002] Strip springs are widely used in the production of nuclear fuel elements and play a key supporting role. Therefore, their fatigue performance is directly related to the service life and reliability of the equipment. However, due to the special size of strip springs and the complex stress conditions during service, the current testing and research on the fatigue performance of strip springs is based on a single spring or simplified actual working conditions. With the improvement of equipment quality and service life requirements, traditional testing methods and means can no longer meet the needs of engineering applications. Therefore, there is an urgent need for suitable equipment to test the fatigue performance of the strip spring as a whole according to actual service conditions. Summary of the invention

[0003] In order to overcome the problems existing in the related art, a strip spring integral fatigue test fixture is provided.

[0004] According to one aspect of an embodiment of the present disclosure, a strip spring integral fatigue test fixture is provided, the strip spring integral fatigue test fixture comprising: a bottom plate, a positioning plate, a pressing plate, a test rod, and a plurality of pads;

[0005] The upper surface of the bottom plate is provided with a plurality of grooves, each groove is embedded with a cushion block, and the arc-shaped upper surface of each cushion block faces the opening of the embedded groove;

[0006] The positioning plate is connected above the bottom plate, and the positioning plate is a circular frame structure. The inner frame contour of the positioning plate is adapted to the edge contour of the strip spring to be tested, so that the strip spring to be tested is embedded in the inner frame of the positioning plate and covers a plurality of pads. The distribution of the pads embedded in each groove is adapted to the distribution of the steel convexities on the lower surface of the strip spring to be tested, and the upper surface of each pad can contact with a steel convexity.

[0007] The pressure plate cover is arranged above the positioning plate, and the pressure plate and the positioning plate are connected to each other to clamp and fix the edge of the strip spring to be tested; the pressure plate is a circular frame structure;

[0008] The upper end of the test rod is connected to a fatigue testing machine, and the lower end of the test rod passes through the inner frame of the pressure plate and is pressed against the gasket of the strip spring to be tested. The fatigue testing machine is used to apply multiple preset threshold pressures to the test rod to test the fatigue pressure value of the strip spring to be tested.

[0009] In a possible implementation, the plurality of pads are divided into a plurality of groups, the pads in each group have the same height, the number of pads in each group is the same as the number of the plurality of grooves, and the pads in different groups have different heights.

[0010] In a possible implementation, the bottom plate is a circular frame structure.

[0011] In a possible implementation, the lower end of the test rod includes a plurality of pressure heads, and each pressure head can press against a spring leaf of the strip spring to be tested.

[0012] In a possible implementation manner, the positioning plate is connected to the base plate by a plurality of screws.

[0013] In a possible implementation, the pressing plate is connected to the positioning plate and the bottom plate respectively through a plurality of screws.

[0014] In a possible implementation, a plurality of positioning grooves are provided on the edge of the strip spring to be tested, and a plurality of positioning threaded holes are provided along the axial direction on the bottom plate, the positioning plate and the pressing plate;

[0015] The strip spring integral fatigue test fixture also includes a plurality of positioning screws, each of which is threadedly connected to a positioning threaded hole of the base plate, a positioning threaded hole of a positioning plate and a positioning threaded hole of a pressure plate, and is clamped in a positioning groove.

[0016] In a possible implementation, the curvature of the upper surface of the cushion block and the curvature of the lower surface of the test rod are consistent with the curvature of the side surface of the fuel rod.

[0017] In a possible implementation, the strip spring integral fatigue test fixture further includes a plurality of baffles, each of which is connected to a side surface of the base plate.

[0018] In a possible implementation manner, each baffle is connected to the base plate via screws.

[0019] The beneficial effects of the present disclosure are as follows: the present disclosure uses the bottom plate positioning plate and the pressure plate to clamp the strip spring to be tested, and uses the pad and the test rod to press the steel convex and the spring piece of the strip spring, which realistically simulates the real service constraint conditions of the strip spring and solves the problem of being unable to test and study the overall fatigue performance of the strip spring. Thus, the simulation and testing of the real working conditions of the spring can be realized, which provides important theoretical guidance and technical support for studying the fatigue performance of the strip spring and has important scientific significance and engineering application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a strip spring integral fatigue test fixture according to an exemplary embodiment.

[0021] Figure 2 is a cross-sectional view of a base plate according to an exemplary embodiment.

[0022] Figure 3 is a top view of a base plate according to an exemplary embodiment.

[0023] Figure 4 is a cross-sectional view of a positioning plate according to an exemplary embodiment.

[0024] Figure 5 is a top view of a positioning plate according to an exemplary embodiment.

[0025] Figure 6 FIG. 4 is a schematic diagram showing a strip spring embedded in a positioning plate according to an exemplary embodiment.

[0026] Figure 7 is a schematic diagram of a pressing plate according to an exemplary embodiment.

[0027] Figure 8 is a top view of a pressing plate according to an exemplary embodiment.

[0028] Fig. 9 The figure is a top view of a strip spring integral fatigue test fixture according to an exemplary embodiment. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] In the present disclosure, one side of the strip spring may be a steel bulge, and the other side of the strip spring opposite to the steel bulge may be a spring sheet. During the actual service of the strip spring, the steel bulge and the spring sheet of the strip spring are squeezed by different fuel rods at the same time.

[0031] Figure 1 It is a schematic diagram of a strip spring integral fatigue test fixture according to an exemplary embodiment. Figure 2 is a cross-sectional view of a base plate according to an exemplary embodiment. Figure 3 FIG. 1 is a top view of a bottom plate according to an exemplary embodiment. Figure 1 As shown, the strip spring integral fatigue test fixture comprises: a bottom plate 6, a positioning plate 5, a pressing plate 4, a test rod (not shown in the figure) and a plurality of pads 8;

[0032] like Figures 1 to 3 As shown, the upper surface of the bottom plate 6 is provided with a plurality of grooves, such as Figure 1 As shown, a pad 8 can be embedded in each groove, and the arc-shaped upper surface of each pad 8 faces the opening of the embedded groove.

[0033] like Figure 1 As shown, the positioning plate 5 is connected above the base plate 6 , for example, the base plate 6 and the positioning plate 5 can be connected by screws 1 .

[0034] Figure 4 is a cross-sectional view of a positioning plate according to an exemplary embodiment. Figure 5 is a top view of a positioning plate according to an exemplary embodiment. Figure 6 FIG. 1 is a schematic diagram showing a strip spring embedded in a positioning plate according to an exemplary embodiment. Figures 4 to 6 As shown, the positioning plate is a circular frame structure. Figure 6 As shown, the inner frame contour of the positioning plate 5 is adapted to the edge contour of the strip spring 13 to be tested, so that the strip spring 13 to be tested is embedded in the inner frame of the positioning plate. Figure 1 As shown, the strip spring 13 to be tested covers a plurality of pads 8, and the distribution of the pads embedded in each groove matches the distribution of the steel protrusions 12 on the lower surface of the strip spring 13 to be tested, and the upper surface of each pad 8 can contact a steel protrusion 12, and the position where the lower surface of the strip spring 13 to be tested and the steel protrusion 12 are directly opposite is the spring piece 11;

[0035] like Figure 1 As shown, the pressing plate 4 is covered on the positioning plate 5. For example, the pressing plate 4 can be connected with the positioning plate 5 and the bottom plate 6 by screws 1. The pressing plate and the positioning plate are connected to each other to clamp and fix the edge of the strip spring to be tested.

[0036] Figure 7 is a schematic diagram of a pressing plate according to an exemplary embodiment. Figure 8 FIG. 1 is a top view of a pressure plate according to an exemplary embodiment. Figures 7 and 8 As shown, the pressing plate is a circular frame structure, such as Figure 1 As shown, the inner frame of the pressure plate can expose the strip spring to be tested.

[0037] The upper end of the test rod is connected to a fatigue testing machine (not shown in the figure), and the lower end of the test rod passes through the inner frame of the pressure plate and is pressed against the spring sheet of the strip spring to be tested. The fatigue testing machine is used to apply multiple preset threshold pressures to the test rod to test the fatigue pressure value of the strip spring to be tested.

[0038] During the fatigue test, it is ensured that the contact surface between the tested strip spring and the fuel rod is subjected to positive pressure during the entire test process. During the test, the tested strip spring is compressed to the nominal displacement, and then a certain amount of compression is applied. At this position, the load is reciprocated according to the cyclic load, and the number of cycles experienced when the tested strip spring is completely broken is recorded; if the tested strip spring is still not broken after 1×107 load cycles, the test can be stopped.

[0039] The present invention uses the bottom plate positioning plate and the pressure plate to clamp the strip spring to be tested, and uses the pad and the test rod to press the steel convex and the spring piece of the strip spring to be tested, which realistically simulates the real service constraint conditions of the strip spring to be tested, and solves the problem of being unable to test and study the overall fatigue performance of the strip spring to be tested. Therefore, the simulation and testing of the real working conditions of the spring can be realized, which provides important theoretical guidance and technical support for studying the fatigue performance of the strip spring to be tested, and has important scientific significance and engineering application value.

[0040] In a possible implementation, the plurality of pads are divided into a plurality of groups, the pads in each group have the same height, the number of pads in each group is the same as the number of the plurality of grooves, and the pads in different groups have different heights. In this way, different pre-deformations when the actual spring is installed can be simulated by inserting pads of different heights.

[0041] In a possible implementation, the bottom plate is a circular frame structure, so that the pad can be easily disassembled and assembled.

[0042] In a possible implementation, the lower end of the test rod includes a plurality of pressure heads, each of which can press against a spring sheet of the strip spring to be tested, thereby testing a plurality of spring sheets at the same time, thereby improving the test efficiency.

[0043] In a possible implementation, a plurality of positioning grooves are provided on the edge of the strip spring to be tested, and a plurality of positioning threaded holes are provided along the axial direction on the bottom plate, the positioning plate and the pressure plate;

[0044] like Figure 1 As shown, the strip spring integral fatigue test fixture further includes a plurality of positioning screws 2, each of which is threadedly connected to a positioning threaded hole of the base plate, a positioning threaded hole of a positioning plate, and a positioning threaded hole of a pressure plate, and is clamped in a positioning groove. In this way, radial displacement of the strip spring to be tested relative to the base plate and the positioning plate can be further effectively avoided.

[0045] Fig. 9 FIG. 1 is a top view of a strip spring integral fatigue test fixture according to an exemplary embodiment. Fig. 9 As shown, the strip spring integral fatigue test fixture further includes a plurality of baffles 10, each of which is connected to a side surface of a bottom plate (not shown in the figure) under the pressure plate 4. This can further effectively fix the strip spring to be tested. Each baffle is connected to the bottom plate by screws.

[0046] The embodiments of the present disclosure have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A strip spring integral fatigue test fixture, characterized in that: The strip spring integral fatigue test fixture comprises: a base plate, a positioning plate, a pressure plate, a test rod and a plurality of pads; The upper surface of the bottom plate is provided with a plurality of grooves, each groove is embedded with a cushion block, and the arc-shaped upper surface of each cushion block faces the opening of the embedded groove; The positioning plate is connected above the bottom plate, and the positioning plate is a circular frame structure. The inner frame contour of the positioning plate is adapted to the edge contour of the strip spring to be tested, so that the strip spring to be tested is embedded in the inner frame of the positioning plate and covers a plurality of pads. The distribution of the pads embedded in each groove is adapted to the distribution of the steel convexities on the lower surface of the strip spring to be tested, and the upper surface of each pad can contact with a steel convexity. The pressure plate cover is arranged above the positioning plate, and the pressure plate and the positioning plate are connected to each other to clamp and fix the edge of the strip spring to be tested; the pressure plate is a circular frame structure; The upper end of the test rod is connected to the fatigue testing machine, and the lower end of the test rod passes through the inner frame of the pressure plate and presses against the spring sheet of the strip spring to be tested. The fatigue testing machine is used to apply multiple preset threshold pressures to the test rod to test the fatigue pressure value of the strip spring to be tested.

2. The strip spring integral fatigue test fixture according to claim 1, characterized in that: The plurality of pads are divided into a plurality of groups, the pads in each group have the same height, the number of pads in each group is the same as the number of the plurality of grooves, and the pads in different groups have different heights.

3. The strip spring integral fatigue test fixture according to claim 1, characterized in that: The bottom plate is a circular frame structure.

4. The strip spring integral fatigue test fixture according to claim 1, characterized in that: The lower end of the test rod includes a plurality of pressure heads, each of which can press against a spring leaf of the strip spring to be tested.

5. The strip spring integral fatigue test fixture according to claim 1, characterized in that: The positioning plate is connected to the bottom plate through a plurality of screws.

6. The strip spring integral fatigue test fixture according to claim 1, characterized in that: The pressing plate is connected to the positioning plate and the bottom plate respectively through a plurality of screws.

7. The strip spring integral fatigue test fixture according to claim 1, characterized in that: A plurality of positioning grooves are provided on the edge of the strip spring to be tested, and a plurality of positioning threaded holes are provided along the axial direction on the bottom plate, the positioning plate and the pressing plate; The strip spring integral fatigue test fixture also includes a plurality of positioning screws, each of which is threadedly connected to a positioning threaded hole of the base plate, a positioning threaded hole of a positioning plate and a positioning threaded hole of a pressure plate, and is clamped in a positioning groove.

8. The strip spring integral fatigue test fixture according to claim 1, characterized in that: The curvature of the upper surface of the pad and the curvature of the lower surface of the test rod are consistent with the curvature of the side surface of the fuel rod.

9. The strip spring integral fatigue test fixture according to claim 1, characterized in that: The strip spring integral fatigue test fixture further comprises a plurality of baffles, each of which is connected to a side surface of the base plate.

10. The strip spring integral fatigue test fixture according to claim 9, characterized in that: Each baffle is connected to the bottom plate by screws.

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