An anti-instability fixture and test device for thin plate strain fatigue performance test

Abstract

The utility model discloses an anti-instability fixture and test device for thin plate strain fatigue performance test, which relates to fatigue test fixture equipment. It includes a first clamp and a second clamp, both of which are symmetrically provided with positioning holes, and positioning bolts are detachably installed in the positioning holes; a specimen is suitable for installation between the first clamp and the second clamp; the first clamp includes an upper plate part and a lower plate part, and a connecting groove is provided between the upper plate part and the lower plate part, and a guide column is installed in the connecting groove, one end of the guide column is connected to the inner wall of the connecting groove of the lower plate part, and the other end of the guide column is installed in the connecting groove in the upper plate part; the second clamp has the same structure as the first clamp. The utility model solves the bending problem and the technical problem of inaccurate positioning of the extensometer in the prior art.

Description

Technical Field

[0001] The utility model relates to a fatigue test fixture, in particular to an anti-instability fixture and a test device for a thin plate strain fatigue performance test. Background Art

[0002] As a new generation of automobile stamping steel, dual-phase steel is widely used in automobile stamping and structural parts due to its high strength, high initial work hardening rate, good stamping forming performance, low yield strength ratio and other advantages [1-2]. The microstructure of dual-phase steel is mainly composed of ferrite and a small amount of martensite. By adjusting the martensite content in dual-phase steel, dual-phase steels of different strength levels can be obtained to meet the strength requirements of different automobile parts [3]. Automobiles are often subjected to continuous alternating loads during driving and will suffer fatigue failure under conditions far below the static strength. Therefore, the materials used are required to have not only good static mechanical properties, but also excellent fatigue properties, especially low-cycle strain fatigue performance indicators, which are particularly important for the safe design of automobile structures. However, due to the thin thickness of cold-rolled dual-phase steel (generally not more than 3mm), it is easy to suffer from lateral buckling instability in the thickness direction when subjected to tension and compression cyclic loads. Therefore, in the strain-controlled low-cycle fatigue test of dual-phase steel thin plates, preventing its instability to obtain reliable test data has become a hot topic for researchers.

[0003] The anti-instability fixture for the thin plate tension and compression fatigue test is used to clamp on both sides of the thin plate. Reference application number: 201610512481.3 Anti-bending device for thin plate tension and compression strain control fatigue test, the same applicant as this applicant, the applicant found in actual use that when the first lower clamping part and the first upper clamping part are relatively separated, it is easy to cause bending of the specimen, especially the greater the separation distance, the easier it is to happen. Furthermore, the existing electronic extensometers are often fixed to the fixture with multiple turns of elastic rope, so the position of the electronic extensometer is often not a fixed position, and the artificial installation position is more arbitrary.

[0004] In view of this, the present utility model is proposed. Utility Model Content

[0005] In order to solve the above technical problems, the basic concept of the technical solution adopted by the utility model is:

[0006] In view of the shortcomings of the prior art, the utility model provides a machine tool with a gantry and an iron chip recovery function. The specific technical solution is as follows:

[0007] An anti-instability fixture for a thin plate strain fatigue performance test comprises a first clamping plate and a second clamping plate, wherein the first clamping plate and the second clamping plate are both symmetrically provided with positioning holes, and positioning bolts are detachably installed in the positioning holes;

[0008] A specimen is suitable for being installed between the first clamping plate and the second clamping plate;

[0009] The first clamping plate includes an upper plate portion and a lower plate portion, wherein a connecting groove is provided between the upper plate portion and the lower plate portion, wherein a guide column is installed in the connecting groove, wherein one end of the guide column is connected to the inner wall of the connecting groove of the lower plate portion, and the other end of the guide column is installed in the connecting groove in the upper plate portion;

[0010] The second clamping plate has the same structure as the first clamping plate. The positioning bolt is suitable for locking the first clamping plate and the second clamping plate; the upper plate portion and the lower plate portion are separated and connected by a guide column. The length of the guide column is suitable for being sufficient for the length after the specimen breaks, that is, it is sufficient to realize the pulling test even in the extreme position, such as in the pulling direction.

[0011] In a further technical solution, a limit block is installed at the upper end of the guide column, and the limit block is installed in the connecting groove; a fixing ring is installed at the port of the connecting groove located on the upper plate, and the outer ring of the fixing ring is fixedly connected to the port of the connecting groove, and the inner diameter of the fixing ring is smaller than the outer diameter of the limit block.

[0012] In a further technical solution, both ends of the first clamping plate and the second clamping plate are provided with clamping parts, and fixing holes are opened on the clamping parts.

[0013] In a further technical solution, two sets of guide posts are provided on the first clamping plate and the second clamping plate, and a clamping portion is symmetrically provided between the upper plate portion and the lower plate portion;

[0014] An observation recess one is arranged in the clamping portion, and the observation recess one is located between the corresponding two groups of guide columns. The observation recesses one of the upper plate portion and the lower plate portion are suitable for being paired to form a forward observation groove.

[0015] In a further technical solution, observation recesses 2 are symmetrically arranged at the clamping parts of the first clamping plate and the second clamping plate, and the two groups of observation recesses 2 are suitable for being combined into lateral observation grooves.

[0016] A test device for an anti-instability fixture for a thin plate strain fatigue performance test, comprising an anti-instability fixture for the test; and a test bench, wherein an upper clamping mechanism is installed on the test bench, a working opening is provided in the test bench, and a lower clamping mechanism is installed in the working opening; the upper clamping mechanism and the lower clamping mechanism respectively clamp two groups of clamping parts;

[0017] A position frame is installed on the test bench, and an electronic extensometer is installed on the position frame.

[0018] In a further technical solution, the positioning frame includes a base plate, which is detachably connected to the test bench and installed outside the working port; a vertical plate is installed on the base plate, a vertical groove is provided in the vertical plate, a horizontal plate is installed in the vertical groove, an elastic clamp is installed on the horizontal plate, and the elastic clamp is provided in multiple groups and installed on multiple groups of side surfaces of the electronic extensometer.

[0019] In a further technical solution, a spur rack and a ratchet bar are respectively arranged in the vertical groove, and the spur rack is located on the side of the ratchet bar relative to the anti-instability clamp; the ratchet bar is provided with ratchets and tilted upward, suitable for being clamped by the limit piece.

[0020] A center block is arranged at the bottom side of the transverse plate, a mounting hole is opened in the center block, and an adjusting shaft is installed in the mounting hole, and a connecting bearing is installed at one end of the adjusting shaft and is installed in the mounting hole;

[0021] The adjusting shaft extends out of the vertical slot and is equipped with an adjusting knob, a connecting gear is installed on the adjusting shaft, and the connecting gear is meshed with the spur rack;

[0022] A lower bending shaft is installed at the bottom of the middle block, and a limiting member is installed on the lower bending shaft. The limiting member is suitable for abutting against the ratchet bar.

[0023] In a further technical solution, the limiter comprises a collar, a left plate and a right plate, the collar is provided with a mounting groove; the tops of the left plate and the right plate are limitedly mounted in the mounting groove, and a return spring is installed between the left plate and the right plate;

[0024] The ratchet bars are provided in two groups, and the bottoms of the left plate and the right plate are movably connected to the corresponding ratchet bars respectively; and a protective plate is provided on the side of the left plate and the right plate which is relatively far away from the spur rack.

[0025] Beneficial effects:

[0026] 1. The utility model realizes the directional movement of the upper plate and the lower plate through the guide column, and has a good guiding effect in different strain fatigue performance tests.

[0027] 2. The utility model realizes the detection of different extensometers by setting a forward observation slot and a lateral observation slot, so as to facilitate strain observation and data recording and collection.

[0028] 3. The utility model moves the electronic extensometer up and down by setting a position frame, realizes the up and down movement by the meshing of the gear and the spur rack, and realizes the failure of the limiter by the reset spring to achieve the movement effect of the gear rack meshing; and then realizes the ratchet effect of the left plate and the right plate on the ratchet plate to achieve the fixing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the utility model or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] In the attached picture:

[0031] Figure 1 It is a schematic diagram of an existing anti-instability fixture;

[0032] Figure 2 It is a schematic diagram of the anti-instability clamp in the utility model;

[0033] Figure 3 This is a schematic diagram of the first splint in the utility model;

[0034] Figure 4 It is a cross-sectional view of the connecting groove of the first clamping plate in the utility model;

[0035] Figure 5 This is another schematic diagram of a first splint of the utility model;

[0036] Figure 6 This is a schematic diagram of another anti-instability clamp of the utility model;

[0037] Figure 7 This is a front schematic diagram of the test bench of the utility model;

[0038] Figure 8 It is a structural diagram of the position frame of the utility model;

[0039] Fig. 9 It is a vertical cross-sectional view of the vertical plate and the horizontal plate of the utility model along the vertical groove;

[0040] Fig.10 It is a side sectional view of the limiting member of the utility model.

[0041] In the figure: 1. first clamping plate; 2. second clamping plate; 3. positioning hole; 4. positioning bolt; 5. upper plate; 6. lower plate; 7. connecting groove; 8. guide column; 9. limit block; 10. fixing ring; 11. clamping part; 12. fixing hole; 13. clamping mouth; 14. observation notch one; 15. observation notch two; 16. upper clamping mechanism; 17. lower clamping mechanism; 18. bottom plate; 19. vertical plate; 20. horizontal plate; 21. elastic clamping plate; 22. straight rack; 23. ratchet; 24. neutral block; 25. adjusting shaft; 26. connecting bearing; 27. adjusting knob; 28. connecting gear; 29. ​​lower bending shaft; 30. collar; 31. left plate; 32. right plate; 33. reset spring; 34. protective plate; 100. specimen; 200. electronic extensometer. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail in combination with the embodiments below. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.

[0043] The application principle of the utility model is further described below in conjunction with the accompanying drawings and specific embodiments.

[0044] Figure 1 It is a clamp currently available and is often used for strain fatigue performance testing of thin plate specimens. The thickness of thin plate metal specimens is usually less than 3mm.

[0045] Example 1

[0046] like Figures 2 to 4 As shown, it is an embodiment of the utility model, an anti-instability fixture for thin plate strain fatigue performance test, comprising a first clamping plate 1 and a second clamping plate 2, wherein the first clamping plate 1 and the second clamping plate 2 are both symmetrically provided with positioning holes 3, and positioning bolts 4 are detachably installed in the positioning holes 3; a sample 100 is suitable for being installed between the first clamping plate 1 and the second clamping plate 2;

[0047] The first clamping plate 1 includes an upper plate portion 5 and a lower plate portion 6, and a connecting groove 7 is provided between the upper plate portion 5 and the lower plate portion 6, and a guide column 8 is installed in the connecting groove 7, one end of the guide column 8 is connected to the inner wall of the connecting groove 7 of the lower plate portion 6, and the other end of the guide column 8 is installed in the connecting groove 7 in the upper plate portion 5; the second clamping plate 2 has the same structure as the first clamping plate 1. After the first clamping plate and the second clamping plate are symmetrically assembled, the positioning bolts 4 are passed through the positioning holes 3 for locking and installation, and the positioning nuts are installed and locked if necessary. The strain fatigue test is performed by pulling, pulling, pressing, and pressing tests at both ends of the clamp. By installing the guide column 8, the output direction is ensured to reduce the probability of bending of the specimen and avoid affecting the test.

[0048] exist Figure 4 It can be known that a limit block 9 is installed at the upper end of the guide column 8, and the limit block 9 is installed in the connection groove 7; a fixing ring 10 is installed at the port of the connection groove 7 located at the upper plate 5, and the outer ring of the fixing ring 10 is fixedly connected to the port of the connection groove 7, and the inner diameter of the fixing ring 10 is smaller than the outer diameter of the limit block 9. Further, the limit block 9 can be preferentially installed into the connection groove, and then the fixing ring 10 can be welded at the notch of the connection groove to realize that the two ends of the guide column are restricted in the upper plate and the lower plate. Both ends of the first clamping plate 1 and the second clamping plate 2 are provided with a clamping portion 11, and a fixing hole 12 is opened on the clamping portion 11.

[0049] Example 2

[0050] like Figure 5 and Figure 6 As shown, another embodiment of the utility model is shown, based on Example 1, considering that the clamp is used to close to the sample in practice, the collected data of surface strain is easily disturbed by the clamp. Therefore, a larger observation slot is set. Two sets of guide columns 8 are set on the first clamping plate 1 and the second clamping plate 2, and a clamping portion 13 is symmetrically set between the upper plate portion 5 and the lower plate portion 6;

[0051] An observation recess 14 is provided in the clamping portion 13 , and the observation recess 14 is located between the corresponding two groups of guide columns 8 . The observation recesses 14 of the upper plate portion 5 and the lower plate portion 6 are suitable for being paired to form a forward observation groove.

[0052] The clamping portions 13 of the first clamping plate 1 and the second clamping plate 2 are symmetrically provided with second observation notches 15 , and the two groups of second observation notches 15 are suitable for being combined into lateral observation slots.

[0053] Example 3

[0054] like Figures 7 to 10 As shown, it is another implementation scheme of the utility model, which is designed on the basis of Example 1 in order to realize stable fixation of the electronic extensometer so that it can be used to observe different positions of different samples. Specifically, it includes a test device of an anti-instability fixture for thin plate strain fatigue performance test, including an anti-instability fixture for test; and also includes a test bench, on which an upper clamping mechanism 16 is installed, a working opening is opened in the test bench, and a lower clamping mechanism 17 is installed in the working opening; the upper clamping mechanism 16 and the lower clamping mechanism 17 respectively clamp two groups of clamping parts 11;

[0055] A position frame is installed on the test bench, and an electronic extensometer 200 is installed on the position frame.

[0056] like Figure 8As shown, the position frame includes a base plate 18, which is detachably connected to the test bench and installed outside the working port; a vertical plate 19 is installed on the base plate 18, a vertical groove is provided in the vertical plate 19, a horizontal plate 20 is installed in the vertical groove, and an elastic clamp 21 is installed on the horizontal plate 20, and the elastic clamp 21 is provided in multiple groups and installed on multiple groups of side surfaces of the electronic extensometer 200.

[0057] like Fig. 9 As shown, a spur rack 22 and a ratchet bar 23 are respectively arranged in the vertical groove, and the spur rack 22 is located on the side of the ratchet bar 23 opposite to the anti-instability clamp; a center block 24 is arranged on the bottom side of the transverse plate 20, and a mounting hole is opened in the center block 24, and an adjusting shaft 25 is installed in the mounting hole, and one end of the adjusting shaft 25 is installed with a connecting bearing 26 and installed in the mounting hole; the adjusting shaft 25 extends to the outside of the vertical groove and is installed with an adjusting knob 27, and a connecting gear 28 is installed on the adjusting shaft 25, and the connecting gear 28 is meshed with the spur rack 22; a lower bending shaft 29 is installed at the bottom of the center block 24, and a limiting member is installed on the lower bending shaft 29, and the limiting member is suitable for abutting against the ratchet bar 23.

[0058] like Fig.10 As shown, the limiting member includes a collar 30, a left plate 31 and a right plate 32, and a mounting groove is provided on the collar 30; the tops of the left plate 31 and the right plate 32 are limitedly installed in the mounting groove, and a return spring 33 is installed between the left plate 31 and the right plate 32; the ratchet bars 23 are provided with two groups, and the bottoms of the left plate 31 and the right plate 32 are movably connected with the corresponding ratchet bars 23 respectively; the left plate 31 and the right plate 32 are both provided with a protective plate 34 on the side relatively away from the spur rack 22;

[0059] The tops of the left plate and the right plate can be rotatably connected in the mounting groove, and the support on both sides can be achieved by the reset spring. By manually pinching the protective plate, the left plate and the right plate can be brought closer and detached from the ratchet plate. At the appropriate position, the two sets of protective plates are loosened, and the reset spring is used to open them to both sides and abut against the ratchet on the ratchet plate to achieve an abutment limiting effect.

[0060] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0061] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An anti-instability fixture for thin plate strain fatigue performance test, characterized in that: It comprises a first clamping plate (1) and a second clamping plate (2), wherein the first clamping plate (1) and the second clamping plate (2) are both symmetrically provided with positioning holes (3), and positioning bolts (4) are detachably installed in the positioning holes (3); A sample (100) is suitable for being installed between the first clamping plate (1) and the second clamping plate (2); The first clamping plate (1) comprises an upper plate portion (5) and a lower plate portion (6), a connecting groove (7) is provided between the upper plate portion (5) and the lower plate portion (6), a guide column (8) is installed in the connecting groove (7), one end of the guide column (8) is connected to the inner wall of the connecting groove (7) of the lower plate portion (6), and the other end of the guide column (8) is installed in the connecting groove (7) in the upper plate portion (5); The second clamping plate (2) has the same structure as the first clamping plate (1).

2. The anti-instability fixture for thin plate strain fatigue performance test according to claim 1, characterized in that: A limit block (9) is installed at the upper end of the guide column (8), and the limit block (9) is installed in the connecting groove (7); a fixing ring (10) is installed at the end of the connecting groove (7) located on the upper plate portion (5), and the outer ring of the fixing ring (10) is fixedly connected to the end of the connecting groove (7), and the inner diameter of the fixing ring (10) is smaller than the outer diameter of the limit block (9).

3. The anti-instability fixture for thin plate strain fatigue performance test according to claim 2, characterized in that: Both ends of the first clamping plate (1) and the second clamping plate (2) are provided with clamping parts (11), and the clamping parts (11) are provided with fixing holes (12).

4. The anti-instability fixture for thin plate strain fatigue performance test according to claim 2, characterized in that: Two groups of guide posts (8) are provided on the first clamping plate (1) and the second clamping plate (2), and a clamping portion (13) is symmetrically provided between the upper plate portion (5) and the lower plate portion (6); An observation recess (14) is provided in the clamping portion (13), and the observation recess (14) is located between the two corresponding groups of guide columns (8). The observation recesses (14) of the upper plate portion (5) and the lower plate portion (6) are suitable for being paired to form a forward observation groove.

5. The anti-instability fixture for thin plate strain fatigue performance test according to claim 2, characterized in that: The clamping portions (13) of the first clamping plate (1) and the second clamping plate (2) are symmetrically provided with observation notches 2 (15), and the two groups of observation notches 2 (15) are suitable for being combined into lateral observation slots.

6. A test device for an anti-instability fixture for a thin plate strain fatigue performance test, characterized in that: The invention comprises the anti-instability fixture for testing as claimed in claim 5; and further comprises a test bench, wherein an upper clamping mechanism (16) is installed on the test bench, a working opening is opened in the test bench, and a lower clamping mechanism (17) is installed in the working opening; the upper clamping mechanism (16) and the lower clamping mechanism (17) respectively clamp two groups of clamping parts (11); A position frame is installed on the test bench, and an electronic extensometer (200) is installed on the position frame.

7. The test device of the anti-instability fixture for thin plate strain fatigue performance test according to claim 6, characterized in that: The positioning frame comprises a base plate (18), the base plate (18) is detachably connected to the test bench and is installed outside the working port; a vertical plate (19) is installed on the base plate (18), a vertical groove is provided in the vertical plate (19), a horizontal plate (20) is installed in the vertical groove, an elastic clamping plate (21) is installed on the horizontal plate (20), and the elastic clamping plates (21) are provided in multiple groups and are installed on multiple groups of side surfaces of the electronic extensometer (200).

8. The test device of the anti-instability fixture for thin plate strain fatigue performance test according to claim 7, characterized in that: A spur rack (22) and a ratchet rack (23) are respectively arranged in the vertical groove, and the spur rack (22) is located on a side of the ratchet rack (23) opposite to the anti-instability clamp; A center block (24) is arranged on the bottom side of the transverse plate (20), a mounting hole is provided in the center block (24), an adjustment shaft (25) is installed in the mounting hole, and a connecting bearing (26) is installed at one end of the adjustment shaft (25) and is installed in the mounting hole; The adjusting shaft (25) extends outside the vertical slot and is provided with an adjusting knob (27); a connecting gear (28) is provided on the adjusting shaft (25), and the connecting gear (28) is meshed with the spur rack (22); A lower bending shaft (29) is installed at the bottom of the middle block (24), and a limiting member is installed on the lower bending shaft (29), and the limiting member is suitable for abutting against the ratchet bar (23).

9. The test device of the anti-instability fixture for thin plate strain fatigue performance test according to claim 8, characterized in that: The limiting member comprises a collar (30), a left plate (31) and a right plate (32); a mounting groove is arranged on the outer surface of the collar (30); the tops of the left plate (31) and the right plate (32) are limitedly mounted in the mounting groove; a return spring (33) is installed between the left plate (31) and the right plate (32); The ratchet bars (23) are provided in two groups, and the bottoms of the left plate (31) and the right plate (32) are movably connected to the corresponding ratchet bars (23) respectively; and a protective plate (34) is provided on the side of the left plate (31) and the right plate (32) which is relatively far away from the spur rack (22).

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