Corrosion fatigue test clamp

Abstract

The utility model discloses a corrosion fatigue test clamp. A clamping rod penetrating hole is formed in the center of a bottom plate of a corrosive liquid container; the lower end of the clamping rod is clamped and fixed on a lower chuck of the fatigue testing machine, and the upper end of the clamping rod penetrates into the corrosive liquid container through the clamping rod penetrating hole; the center of the lower surface of the supporting disc is fixedly connected with the upper end of the clamping rod; the locking nut is positioned outside the lower part of the bottom plate of the corrosive liquid container and is screwed on the clamping rod; the sealing gasket is positioned between the supporting disc and the bottom plate of the corrosive liquid container and is sleeved on the clamping rod; the pressing disc is located in the corrosive liquid container and located above the supporting disc. The pressing bolt is connected between the pressing disc and the supporting disc; the lower end of the sample vertically abuts against the center of the upper surface of the supporting disc. The outer side of the sample lower clamping section is sleeved with the pressing sleeve, and the outer side of the pressing sleeve is sleeved with the pressing disc; the middle reducing section of the sample is positioned inside the corrosive liquid container, and the upper clamping section of the sample extends to the outside above the corrosive liquid container and is clamped and fixed on the upper chuck of the fatigue testing machine.

Description

Technical Field

[0001] The utility model belongs to the technical field of metal corrosion fatigue tests, and particularly relates to a corrosion fatigue test fixture. Background Art

[0002] In various engineering applications, the fatigue performance of materials plays a crucial role in the safety of the overall project. According to statistics, component failures caused by metal material fatigue account for about 80% of all component failures. The fatigue fracture of components often has the characteristics of suddenness, high locality, and disaster.

[0003] With the rapid development of industry, the working conditions of metal components have become increasingly complex. In addition to serving in the conventional atmospheric environment, more and more metal components are applied in corrosive environments. Due to the particularity of the service conditions, once a metal component undergoes fatigue fracture, it will cause huge safety accidents and incalculable economic losses. Therefore, it is particularly important to carry out fatigue tests on metal components in corrosive environments.

[0004] In the corrosion high-cycle fatigue test, for the requirement that the specimen needs to be immersed in the corrosive solution, the traditional solution is relatively simple. First, the lower clamping end of the specimen is lengthened, and a round hole is machined in the center of the bottom plate of the corrosive solution container. Then, the lower clamping end of the specimen is passed through the round hole, and then the lower clamping end of the specimen is adhesively bonded and sealed to the bottom plate of the corrosive solution container at the round hole using an adhesive. During the test, the upper and lower clamping ends of the specimen are respectively clamped between the upper and lower chucks of the fatigue testing machine, and the middle reduced diameter section of the specimen is located inside the corrosive solution container.

[0005] However, the above solution has obvious drawbacks. First, during the curing process of the adhesive, the positions of the corrosive solution container and the specimen are likely to shift, which may result in insecure bonding, liquid leakage, etc. During the test, there is a risk that the corrosive solution container leaks liquid or even falls off from the lower clamping end of the specimen, which will not only cause the fatigue test data to be unusable, but also the spilled corrosive solution will harm the test personnel and the fatigue testing machine.

[0006] In addition, after the lower clamping end of the specimen is bonded to the bottom plate of the corrosion liquid container, it needs to be left standing for a period of time to ensure that the bonding between the lower clamping end of the specimen and the bottom plate of the corrosion liquid container is as firm as possible. However, in high-cycle fatigue tests, the high-stress part of the test progresses very quickly. To ensure the test efficiency, a large number of corrosion liquid containers need to be prepared. Moreover, after the test, the separation of the specimen from the corrosion liquid container is also very troublesome, and it is easy to damage the surface and fracture of the specimen during the removal of the binder, thus causing great trouble to the subsequent research work. In addition, most of the corrosion liquid containers are made of acrylic materials and are easily damaged under stress. Therefore, in terms of test efficiency and test economy, the traditional solutions are difficult to meet the requirements of corrosion fatigue tests. Summary of the Invention

[0007] Aiming at the problems existing in the prior art, the present invention provides a corrosion fatigue test fixture, which abandons the traditional method of fixing the specimen and the corrosion liquid container with a binder, can realize the rapid installation and disassembly of the specimen and the corrosion liquid container, and the installation and disassembly process is simple and easy to operate. During the test, the problems of liquid leakage and falling off of the corrosion liquid container can be effectively avoided. The fixture after disassembly can be reused, can adapt to specimens of different sizes, can greatly improve the test efficiency, and at the same time reduce the test cost.

[0008] To achieve the above object, the present invention adopts the following technical solutions: A corrosion fatigue test fixture includes a specimen, a corrosion liquid container, a compression sleeve, a compression plate, a compression bolt, a support plate, a clamping rod, a sealing gasket and a locking nut; a clamping rod through-hole is provided at the center of the bottom plate of the corrosion liquid container; the lower end of the clamping rod is clamped and fixed on the lower chuck of the fatigue testing machine, and the upper end of the clamping rod passes through the clamping rod through-hole into the interior of the corrosion liquid container; the support plate is located inside the corrosion liquid container, and the center of the lower surface of the support plate is fixedly connected to the upper end of the clamping rod; the locking nut is located outside the bottom of the corrosion liquid container and is screwed onto the clamping rod; the sealing gasket is located between the support plate and the bottom plate of the corrosion liquid container and is sleeved on the clamping rod; the compression plate is located inside the corrosion liquid container and is arranged directly above the support plate; the compression bolt is connected between the compression plate and the support plate; the lower end of the specimen vertically abuts against the center of the upper surface of the support plate; the compression sleeve is sleeved on the outer side of the lower clamping section of the specimen, and the compression plate is sleeved on the outer side of the compression sleeve; the middle reduced-diameter section of the specimen is located inside the corrosion liquid container, and the upper clamping section of the specimen extends above the corrosion liquid container to the outside, and the upper clamping section of the specimen is clamped and fixed on the upper chuck of the fatigue testing machine.

[0009] A positioning convex block is provided at the bottom end of the lower clamping section of the specimen, and the cross-sectional shape of the positioning convex block is circular; a positioning groove is provided at the center of the upper surface of the support plate, and the cross-sectional shape of the positioning groove is circular, and the positioning groove is in plug-in fit with the positioning convex block.

[0010] The diameter of the positioning bump is larger than the diameter of the lower clamping section of the specimen. The diameter of the positioning bump is equal to the diameter of the positioning groove, and the axial length of the positioning bump is greater than the axial depth of the positioning groove.

[0011] The outer surface of the pressing sleeve adopts a two-stage stepped cylindrical surface structure, which is respectively denoted as a large-diameter cylindrical section and a small-diameter cylindrical section. A two-stage stepped cylindrical hole is provided at the center of the pressing disc, which is respectively denoted as a large-diameter cylindrical hole and a small-diameter cylindrical hole. The pressing sleeve is inserted and matched with the two-stage stepped cylindrical hole at the center of the pressing disc through the two-stage stepped cylindrical surface structure on the outer surface.

[0012] The diameter of the large-diameter cylindrical section is equal to the diameter of the large-diameter cylindrical hole, and the axial length of the large-diameter cylindrical section is greater than the axial depth of the large-diameter cylindrical hole. The diameter of the small-diameter cylindrical section is equal to the diameter of the small-diameter cylindrical hole, and the axial length of the small-diameter cylindrical section is greater than the axial depth of the small-diameter cylindrical hole.

[0013] The number of the pressing sleeves is several. The sizes of the two-stage stepped cylindrical surface structures on the outer surfaces of the several pressing sleeves are exactly the same, and the diameter of the central hole of the several pressing sleeves is adaptively selected according to the diameter of the lower clamping section of the specimen.

[0014] A number of bolt through holes are uniformly arranged on the disc body of the pressing disc along the circumferential direction. A number of blind threaded holes are uniformly arranged on the upper surface of the disc body of the support disc along the circumferential direction. The number of the blind threaded holes is the same as that of the bolt through holes and the positions correspond one by one.

[0015] The nut of the pressing bolt is located above the bolt through hole, and the screw rod of the pressing bolt passes through the bolt through hole and is screwed with the blind threaded hole.

[0016] The support disc and the clamping rod adopt an integral structure. An external thread is provided on the outer surface of the upper half of the clamping rod. The locking nut is threadedly connected with the upper half of the clamping rod, and the number of the locking nuts is at least one.

[0017] The beneficial effects of the present utility model:

[0018] The corrosion fatigue test fixture of the present utility model abandons the traditional method of fixing the specimen and the corrosion liquid container by using an adhesive, can realize the rapid installation and disassembly of the specimen and the corrosion liquid container, and the installation and disassembly processes are simple and easy to operate. During the test, the problems of liquid leakage and falling off of the corrosion liquid container can be effectively avoided. The fixture after disassembly can be reused, can be adapted to specimens of different sizes, can greatly improve the test efficiency, and simultaneously reduce the test cost. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the overall structure of the corrosion fatigue test fixture of the present utility model;

[0020] Figure 2 Schematic diagram of the specimen structure of the corrosion fatigue test fixture of the present utility model;

[0021] Figure 3 Schematic diagram of the compression sleeve structure of the corrosion fatigue test fixture of the present utility model;

[0022] Figure 4 Schematic diagram of the compression disc structure of the corrosion fatigue test fixture of the present utility model;

[0023] Figure 5 Schematic diagram of the combined structure of the support disc and the clamping rod of the corrosion fatigue test fixture of the present utility model;

[0024] In the figure, 1 - specimen, 2 - corrosion liquid container, 3 - compression sleeve, 4 - compression disc, 5 - compression bolt, 6 - support disc, 7 - clamping rod, 8 - sealing washer, 9 - locking nut, 10 - clamping rod through hole, 11 - positioning convex block, 12 - positioning groove, 13 - large-diameter cylindrical section, 14 - small-diameter cylindrical section, 15 - large-diameter cylindrical hole, 16 - small-diameter cylindrical hole, 17 - bolt through hole, 18 - threaded blind hole. Specific embodiments

[0025] The following further describes the present utility model in detail with reference to the accompanying drawings and specific embodiments.

[0026] As Figures 1 to 5 shown, a corrosion fatigue test fixture includes a specimen 1, a corrosion liquid container 2, a compression sleeve 3, a compression disc 4, a compression bolt 5, a support disc 6, a clamping rod 7, a sealing washer 8 and a locking nut 9; a clamping rod through hole 10 is provided at the center of the bottom plate of the corrosion liquid container 2; the lower end of the clamping rod 7 is clamped and fixed on the lower chuck of the fatigue testing machine, and the upper end of the clamping rod 7 passes through the clamping rod through hole 10 and enters the interior of the corrosion liquid container 2; the support disc 6 is located inside the corrosion liquid container 2, and the center of the lower surface of the support disc 6 is fixedly connected to the upper end of the clamping rod 7; the locking nut 9 is located outside the bottom plate of the corrosion liquid container 2 and is screwed onto the clamping rod 7; the sealing washer 8 is located between the support disc 6 and the bottom plate of the corrosion liquid container 2 and is sleeved on the clamping rod 7; the compression disc 4 is located inside the corrosion liquid container 2 and is arranged directly above the support disc 6; the compression bolt 5 is connected between the compression disc 4 and the support disc 6; the lower end of the specimen 1 vertically abuts against the center of the upper surface of the support disc 6; the compression sleeve 3 is sleeved on the outer side of the lower clamping section of the specimen 1, and the compression disc 4 is sleeved on the outer side of the compression sleeve 3; the middle reduced-diameter section of the specimen 1 is located inside the corrosion liquid container 2, the upper clamping section of the specimen 1 extends to the outside above the corrosion liquid container 2, and the upper clamping section of the specimen 1 is clamped and fixed on the upper chuck of the fatigue testing machine.

[0027] A positioning convex block 11 is provided at the bottom end of the lower clamping section of the specimen 1, and the cross-sectional shape of the positioning convex block 11 is circular; a positioning groove 12 is provided at the center of the upper surface of the support disk 6, the cross-sectional shape of the positioning groove 12 is circular, and the positioning groove 12 is in plug-in fit with the positioning convex block 11.

[0028] The diameter of the positioning convex block 11 is greater than the diameter of the lower clamping section of the specimen 1, the diameter of the positioning convex block 11 is equal to the diameter of the positioning groove 12, and the axial length of the positioning convex block 11 is greater than the axial depth of the positioning groove 12.

[0029] The outer surface of the pressing sleeve 3 adopts a two-stage stepped cylindrical surface structure, which is respectively denoted as a large-diameter cylindrical section 13 and a small-diameter cylindrical section 14; a two-stage stepped cylindrical hole is provided at the center of the pressing disk 4, which is respectively denoted as a large-diameter cylindrical hole 15 and a small-diameter cylindrical hole 16; the pressing sleeve 3 is in plug-in fit with the two-stage stepped cylindrical hole at the center of the pressing disk 4 through the two-stage stepped cylindrical surface structure on the outer surface.

[0030] The diameter of the large-diameter cylindrical section 13 is equal to the diameter of the large-diameter cylindrical hole 15, and the axial length of the large-diameter cylindrical section 13 is greater than the axial depth of the large-diameter cylindrical hole 15; the diameter of the small-diameter cylindrical section 14 is equal to the diameter of the small-diameter cylindrical hole 16, and the axial length of the small-diameter cylindrical section 14 is greater than the axial depth of the small-diameter cylindrical hole 16.

[0031] The number of the pressing sleeves 3 is several, the sizes of the two-stage stepped cylindrical surface structures on the outer surfaces of the several pressing sleeves 3 are exactly the same, and the diameter of the central hole of the several pressing sleeves 3 is selected to be adapted to the diameter of the lower clamping section of the specimen 1.

[0032] A number of bolt through holes 17 are evenly distributed along the circumferential direction on the disk body of the pressing disk 4; a number of threaded blind holes 18 are evenly distributed along the circumferential direction on the upper surface of the disk body of the support disk 6, and the number of the threaded blind holes 18 is the same as that of the bolt through holes 17 and the positions correspond one by one.

[0033] The nut of the pressing bolt 5 is located above the bolt through hole 17, and the screw rod of the pressing bolt 5 passes through the bolt through hole 17 and is screwed with the threaded blind hole 18.

[0034] The support disk 6 and the clamping rod 7 adopt an integral structure. An external thread is provided on the outer surface of the upper half of the clamping rod 7, and the locking nut 9 is threadedly connected to the upper half of the clamping rod 7, and the number of the locking nuts 9 is at least one.

[0035] The following describes a primary use process of the present invention with reference to the accompanying drawings:

[0036] Firstly, a test sample 1 to be tested is prepared, and according to the diameter of the lower clamping section of the test sample 1, a compression sleeve 3 with a center hole diameter equal to the diameter of the lower clamping section is selected.

[0037] Pick up the support plate 6 and the clamping rod 7 assembly, and insert the sealing gasket 8 on the clamping rod 7 of the assembly, then move the clamping rod 7 toward the container mouth of the corrosive liquid container 2 and move the assembly until the clamping rod 7 passes through the clamping rod insertion hole 10 at the center of the bottom plate of the corrosive liquid container 2 to the outside of the container.

[0038] Pick up the first locking nut 9, insert the first locking nut 9 into the clamping rod 7 and screw it into the external thread of the outer surface of the upper half of the rod body until the first locking nut 9 contacts the lower surface of the bottom plate of the corrosive liquid container 2, then tighten the first locking nut 9, the support plate 6 and the clamping rod 7 assembly is fixed to the corrosive liquid container 2, at this time, the sealing gasket 8 is firmly pressed between the support plate 6 and the bottom plate of the corrosive liquid container 2, and the clamping rod through hole 10 is sealed. In order to ensure the reliability of the support plate 6 and the clamping rod 7 assembly to complete the fixation with the corrosive liquid container 2, the second locking nut 9 can be installed on the clamping rod 7 until the second locking nut 9 contacts the first locking nut 9, and then tighten the second locking nut 9, so as to achieve double insurance.

[0039] Transfer the assembled and fixed support plate 6 and clamping rod 7 combination and the corrosive liquid container 2 as a whole into the fatigue testing machine, and fix the lower half of the clamping rod 7 and the lower chuck of the fatigue testing machine together; then pick up the sample 1, and insert the positioning protrusion 11 at the lower end of the sample 1 downward into the positioning groove 12 at the center of the support plate 6; then pick up the clamping sleeve 3, and insert the large-diameter cylindrical section 13 of the clamping sleeve 3 downward into the sample 1 until the large-diameter cylindrical section 13 is in contact with the positioning protrusion 11; then pick up the clamping plate 4, and insert the large-diameter cylindrical hole 15 on the clamping plate 4 downward into the clamping sleeve 3 until the clamping plate 4 is completely placed on the clamping sleeve 3.

[0040] Pick up four clamping bolts 5, and put the four clamping bolts 5 into the four bolt passage holes 17 of the clamping plate 4 respectively, so that the lower end of the screw rod of the clamping bolt 5 enters the threaded blind hole 18 of the support plate 6, and tighten the clamping bolt 5 to move the clamping bolt 5 downward until the nut of the clamping bolt 5 contacts the upper surface of the clamping plate 4, and then tighten the clamping bolt 5 to complete the clamping and fixing of the clamping plate 4. At the same time, the clamping plate 4 completes the clamping and fixing of the clamping sleeve 3, and the clamping sleeve 3 completes the clamping and fixing of the positioning protrusion 11. Finally, the clamping and fixing of the sample 1 is achieved through the clamping and fixing of the positioning protrusion 11.

[0041] Lower the upper chuck of the fatigue testing machine, and fix the upper clamping section of the specimen 1 to the upper chuck of the fatigue testing machine. At this time, the clamping and fixing of the specimen 1 are completed. Subsequently, the corrosion liquid required for the test can be added into the corrosion liquid container 2 according to the test requirements, and the corrosion environment where the specimen 1 is located is simulated by the corrosion liquid. Then, under the simulated corrosion environment, the fatigue test is started according to the set fatigue test parameters.

[0042] After the fatigue test is completed, first remove the corrosion liquid in the corrosion liquid container 2, and then remove the compression bolt 5 to release the fixation of the specimen 1. If the test continues and the size parameters of the specimen 1 remain unchanged, the installation and test of the subsequent specimen 1 can be completed by referring to the installation and test process of the first specimen 1. If the size parameters of the specimen 1 are adjusted, only the adapted compression sleeve 3 needs to be replaced, and then the installation and test of the subsequent specimen 1 can also be completed by referring to the installation and test process of the first specimen 1. Therefore, the reuse of the fixture and the efficient conduct of the test are realized.

[0043] The solutions in the embodiments are not intended to limit the protection scope of the present invention. Any equivalent implementation or modification without departing from the present invention is included in the protection scope of the present invention.

Claims

1. A corrosion fatigue test fixture, characterized in that: The invention comprises a sample, a corrosive liquid container, a compression sleeve, a compression plate, a compression bolt, a support plate, a clamping rod, a sealing gasket and a locking nut; a clamping rod insertion hole is provided at the center of the bottom plate of the corrosive liquid container; the lower end of the clamping rod is clamped and fixed on the lower clamping head of the fatigue testing machine, and the upper end of the clamping rod is inserted into the corrosive liquid container through the clamping rod insertion hole; the support plate is located inside the corrosive liquid container, and the center of the lower surface of the support plate is fixedly connected to the upper end of the clamping rod; the locking nut is located outside the bottom plate of the corrosive liquid container and is screwed on the clamping rod; the sealing gasket is located outside the bottom plate of the corrosive liquid container and is screwed on the clamping rod; the sealing gasket is located at the bottom of the bottom plate of the corrosive liquid container. The specimen is located between the support plate and the bottom plate of the corrosive liquid container and is sleeved on the clamping rod; the clamping plate is located inside the corrosive liquid container and is arranged directly above the support plate; the clamping bolt is connected between the clamping plate and the support plate; the lower end of the specimen is vertically pressed against the center of the upper surface of the support plate; the clamping sleeve is sleeved on the outside of the lower clamping section of the specimen, and the clamping plate is sleeved on the outside of the clamping sleeve; the middle reduced diameter section of the specimen is located inside the corrosive liquid container, the upper clamping section of the specimen extends to the outside above the corrosive liquid container, and the upper clamping section of the specimen is clamped and fixed on the upper chuck of the fatigue testing machine.

2. A corrosion fatigue test fixture according to claim 1, characterized in that: A positioning protrusion is arranged at the bottom end of the lower clamping section of the sample, and the cross-sectional shape of the positioning protrusion is circular; a positioning groove is opened at the center of the upper surface of the support plate, and the cross-sectional shape of the positioning groove is circular, and the positioning groove is plugged into and matched with the positioning protrusion.

3. A corrosion fatigue test fixture according to claim 2, characterized in that: The diameter of the positioning protrusion is greater than the diameter of the lower clamping section of the sample, the diameter of the positioning protrusion is equal to the diameter of the positioning groove, and the axial length of the positioning protrusion is greater than the axial depth of the positioning groove.

4. A corrosion fatigue test fixture according to claim 1, characterized in that: The outer surface of the clamping sleeve adopts a two-stage stepped cylindrical surface structure, which is respectively recorded as a large-diameter cylindrical section and a small-diameter cylindrical section; a two-stage stepped cylindrical hole is opened at the center of the clamping disk, which is respectively recorded as a large-diameter cylindrical hole and a small-diameter cylindrical hole; the clamping sleeve is plugged into and matched with the two-stage stepped cylindrical hole at the center of the clamping disk through the two-stage stepped cylindrical surface structure on the outer surface.

5. A corrosion fatigue test fixture according to claim 4, characterized in that: The diameter of the large diameter cylindrical section is equal to the diameter of the large diameter cylindrical hole, and the axial length of the large diameter cylindrical section is greater than the axial depth of the large diameter cylindrical hole; the diameter of the small diameter cylindrical section is equal to the diameter of the small diameter cylindrical hole, and the axial length of the small diameter cylindrical section is greater than the axial depth of the small diameter cylindrical hole.

6. A corrosion fatigue test fixture according to claim 1, characterized in that: There are a number of compression sleeves, the dimensions of the two-stage stepped cylindrical surface structures on the outer surfaces of the compression sleeves are completely the same, and the diameters of the center holes of the compression sleeves are selected to match the diameter of the lower clamping section of the sample.

7. The corrosion fatigue test fixture according to claim 1, characterized in that: A plurality of bolt holes are evenly arranged along the circumferential direction on the disc body of the clamping disc; a plurality of threaded blind holes are evenly arranged along the circumferential direction on the upper surface of the disc body of the supporting disc, and the threaded blind holes are the same in number and have one-to-one corresponding positions as the bolt holes.

8. A corrosion fatigue test fixture according to claim 7, characterized in that: The nut of the clamping bolt is located above the bolt passing hole, and the screw rod of the clamping bolt passes through the bolt passing hole and is screwed together with the threaded blind hole.

9. The corrosion fatigue test fixture according to claim 1, characterized in that: The support plate and the clamping rod adopt an integrated structure, an outer thread is provided on the outer surface of the upper half of the clamping rod, the locking nut is threadedly connected to the upper half of the clamping rod, and the number of the locking nut is at least one.

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