An impact test fixture

Abstract

The utility model discloses an impact test frock in aerospace technology field, including the first frock and the second frock of symmetrical setting, the first frock and the second frock all are equipped with the placement hole, two groups the bearing of all being fixedly installed in the placement hole, the first frock and the second frock all are connected with external test platform through the connecting piece, the opposite side of the first frock and the second frock all are fixedly installed with the mounting disc. The utility model discloses the rigid structure design of symmetrical setting first frock and second frock, the material quality reinforcement treatment of collet and the adaptive assembly of high -strength pin shaft, build up stable " frock - collet - pin shaft - test platform " load transfer system, can effectively bear the load demand of big load impact test, fills the design vacancy of domestic big load impact test frock, breaks the application limitation of existing small load frock, satisfies the anti -impact performance test demand of high -end field key bearing component such as aerospace.

Description

Technical Field

[0001] This utility model relates to the field of aerospace technology, and in particular to an impact testing fixture. Background Technology

[0002] In high-end equipment fields such as aerospace, critical load-bearing components often face sudden impact loads during service. Their impact resistance directly determines the structural reliability and operational safety of the equipment. Therefore, specialized impact tests are necessary to accurately verify the impact resistance of these components. Among these tests, high-load impact tests on components with high load-bearing requirements are the core step in evaluating the performance of such components under extreme operating conditions and are of great significance for ensuring the overall safety of the equipment.

[0003] Currently, domestic research and application of impact testing are mostly focused on the field of small-load standard impact testing with proportionally reduced loads. For example, the small-load impact testing fixtures commonly found on the market are mainly adapted to test benches with small load specifications. They fix small-sized specimens with low load requirements through simple clamping and positioning structures to complete performance testing under impact loads. Such fixtures have formed a relatively mature application system in small-load testing scenarios.

[0004] However, in actual large-load impact testing, existing small-load impact testing fixtures and related equipment have certain problems. On the one hand, the load-bearing capacity and structural design of existing fixtures cannot meet the requirements of large-load testing, resulting in a lack of corresponding test fixture support for specimens requiring large-load impact testing, making it difficult to conduct accurate performance evaluation and creating a gap in fixture design in the field of large-load impact testing in China. On the other hand, existing fixtures are prone to asymmetrical stress on specimens during testing, causing the load transfer path to deviate during the test. This not only affects the accuracy and reliability of impact test data, but may also cause damage to the specimens or fixtures themselves due to uneven stress, affecting the smooth progress of the test. Therefore, we urgently need an impact testing fixture to solve the above problems. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a new technical solution for impact testing fixtures. Through the rigid structure of symmetrical fixtures, the angular compensation function of bearings, the stable load transfer of bushings and high-strength pins, and the precise positioning of mounting rings, reliable bearing capacity for large-load impact tests is achieved, effectively avoiding the problem of misalignment of test specimens, filling the gap in domestic fixture design, and ensuring the accuracy of test data.

[0006] The purpose of this utility model is achieved as follows: An impact testing fixture includes a first fixture and a second fixture arranged symmetrically. Both the first fixture and the second fixture have placement holes. Bearings are fixedly installed in both sets of placement holes. Both the first fixture and the second fixture are connected to an external test bench through connectors. Mounting plates are fixedly installed on opposite sides of the first fixture and the second fixture. One set of mounting plates is fixedly connected to a mounting ring for mounting the test specimen, and the other set of mounting plates is fixedly connected to an impact plate for impacting the test specimen.

[0007] Optionally, the connecting component includes bushings symmetrically arranged on the first and second toolings for connection with the test bench, and the two sets of bushings are coaxially arranged with the bearings inside the corresponding first and second toolings.

[0008] Optionally, a pin is coaxially inserted inside the bearing, and the two ends of the pin extend into the bushings on the corresponding sides.

[0009] Optionally, the inner diameter of the mounting ring matches the outer diameter of the impact disc.

[0010] Optionally, flanges are coaxially provided on the first and second toolings and at the corresponding bushings. One end of the flange is connected to the first and second toolings, and the other end is fixedly connected to the corresponding bushing.

[0011] Optionally, the bearing is a radial spherical bearing.

[0012] Optionally, the pin is made of a high-strength alloy.

[0013] Optionally, the bushing is made of 45 steel or 40Cr alloy structural steel.

[0014] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. According to one embodiment of this disclosure, the impact test fixture design, through the rigid structure design of the symmetrically arranged first and second fixtures, combined with the material reinforcement treatment of the bushing and the matching assembly of the high-strength pin, constructs a stable "fixture-shoulder-pin-test bench" load transfer system, which can effectively bear the load requirements of large load impact tests, fills the design gap of large load impact test fixtures in China, breaks the application limitations of existing small load fixtures, and meets the impact performance testing requirements of key load-bearing components in high-end fields such as aerospace.

[0015] 2. According to one embodiment of this disclosure, the impact test fixture design utilizes the angular compensation capability of the bearing, combined with the high-precision coaxial design of the placement hole and the symmetrical center line of the fixture, and the circumferential limiting of the test specimen by the positioning keyway on the inner wall of the mounting ring. At the same time, by utilizing the dimensional adaptability between the mounting ring and the impact plate, it can effectively offset the coaxiality problem caused by the installation deviation of the test bench, the assembly deviation of the test specimen, and the slight deformation of the test specimen during the impact process. This avoids the offset of the impact load transmission, ensures the accuracy and repeatability of the impact test data, and reduces the risk of test errors or component damage caused by the misalignment of the test specimen. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the first and second tooling structures of this utility model.

[0018] Figure 2 This is a schematic diagram of the impact disc structure of this utility model.

[0019] Figure 3 This is a schematic diagram of the installation disk structure of this utility model.

[0020] Figure 4 This is a schematic diagram of the first tooling structure of this utility model.

[0021] Figure 5 This is a schematic diagram of the bushing structure of this utility model.

[0022] Figure 6 This is a schematic diagram of the pin structure of this utility model.

[0023] Figure 7 This is a schematic diagram of the bearing structure of this utility model.

[0024] The following are marked in the diagram: 1. First tooling; 2. Second tooling; 3. Placement hole; 4. Bearing; 5. Mounting plate; 6. Mounting ring; 7. Impact plate; 8. Bushing; 9. Pin; 10. Flange. Detailed Implementation

[0025] 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 protection scope of the present utility model.

[0026] like Figure 1-7 As shown, an impact testing fixture includes a first fixture 1 and a second fixture 2 arranged symmetrically. Both the first fixture 1 and the second fixture 2 are provided with placement holes 3. Bearings 4 are fixedly installed in both sets of placement holes 3. The bearings 4 are radial spherical bearings 4.

[0027] Here, the main body of the first tooling 1 and the second tooling 2 is formed by integral forging of No. 45 steel. After forging, it is normalized to eliminate internal stress. The thickness of the main body of the tooling is controlled at 30-40mm to ensure that the overall structure has the rigidity to resist large load impacts. The axis of the two sets of placement holes 3 is strictly coincident with the symmetrical center line of the first tooling 1 and the second tooling 2, and the coaxiality error is controlled within 0.02mm. The inner wall of the placement hole 3 is treated with high frequency induction hardening, with a hardening layer depth of 2-3mm. After hardening, the hardness reaches HRC40-HRC45, which improves the support strength of the hole wall for the bearing 4 and avoids the deformation of the hole wall under large loads.

[0028] Furthermore, the radial spherical bearing 4 adopts a single-slit outer ring structure. Extreme pressure lithium-based grease is evenly applied to the contact surface between its outer ring and the inner wall of the mounting hole 3. The grease filling amount is 1 / 3 to 1 / 2 of the internal space of the bearing 4. This can reduce the friction loss of the bearing 4 during operation and form a stable oil film under impact load, avoiding wear caused by direct metal contact.

[0029] Furthermore, the overall forging and normalizing treatment of the main body of the tooling, the quenching and strengthening of the placement hole 3, and the material optimization of the bushing 8 (45 steel tempering / 40Cr nitriding and the 40CrNiMoA high-strength design of the pin 9) increase the overall rated load capacity of the tooling to over 80kN. This allows it to be stably adapted to large load impact test scenarios, such as impact testing of large load-bearing components in the aerospace field. It completely fills the design gap of large load impact test tooling in China, breaks the application limitations of existing small load tooling with a load capacity of ≤20kN, and meets the needs of high-end equipment fields for large load impact testing.

[0030] It is important to note that the high-precision coaxial design of the placement hole 3 and the symmetrical center line of the tooling, combined with the angular compensation capability of the radial spherical bearing 4, can compensate for angular deviations of ±3°. In conjunction with the positioning keyway of the mounting ring 6, it ensures that the axis of the test piece coincides with the axis of the tooling, effectively offsetting the coaxiality error caused by the installation deviation of the test bench and the assembly deviation of the test piece. This avoids load transfer offset caused by the misalignment of the test piece during the impact process, and the offset can be controlled within 0.05mm. This ensures the accuracy and repeatability of impact test data, such as impact acceleration and peak impact force, and reduces the risk of test misjudgment due to data distortion.

[0031] Both the first tooling 1 and the second tooling 2 are connected to the external test bench via connecting parts. The connecting parts include bushings 8 symmetrically arranged on the first tooling 1 and the second tooling 2 for connecting to the test bench. The bushings 8 are made of 45 steel or 40Cr alloy structural steel. The two sets of bushings 8 are coaxially arranged with the bearings 4 inside the corresponding first tooling 1 and the second tooling 2. A pin 9 is coaxially inserted inside the bearing 4, and both ends of the pin 9 extend into the bushings 8 on the corresponding sides. The pin 9 is made of high-strength alloy.

[0032] Here, if the bushing 8 is made of 45 steel, it needs to undergo a tempering treatment of "quenching at 840-860℃ + tempering at 550-600℃", and the hardness after treatment is controlled to HRC28-HRC32; if 40Cr alloy structural steel is used, an additional surface gas nitriding treatment is added on the basis of tempering, with a nitriding temperature of 500-520℃, a nitriding time of 15-20h, and a nitriding layer depth of 0.15-0.25mm, to improve the wear resistance and fatigue resistance of the bushing 8; the pin 9 is made of 40CrNiMoA high-strength alloy material, and its surface is treated with hard chrome plating, with a chrome plating layer thickness of 5-10μm and a surface roughness Ra≤0.8μm after chrome plating, which not only enhances the rust resistance of the pin 9, but also improves the surface hardness to resist impact wear.

[0033] Furthermore, the extreme pressure lithium-based grease filling of the radial spherical bearing 4 reduces the friction coefficient between the inner and outer rings of the bearing 4, avoiding component wear caused by dry friction; the chrome plating of the pin 9 and the nitriding treatment of the bushing 8 increase the surface hardness of the components to HRC50 or higher, improving wear resistance by 3-5 times and extending the overall service life of the tooling; at the same time, the long-lasting effect of the grease and the modular design of the components reduce the frequency and cost of later maintenance, improving the economic efficiency of the tooling.

[0034] Flanges 10 are coaxially provided on the first tooling 1 and the second tooling 2 at the corresponding bushing 8. One end of the flange 10 is connected to the first tooling 1 and the second tooling 2, and the other end is fixedly connected to the corresponding bushing 8.

[0035] Here, the connection surfaces of flange 10 with the first tooling 1 and the second tooling 2 are milled, with a flatness error of ≤0.03mm / m. Anaerobic adhesive is applied to the mating surfaces during connection, and six M12 high-strength bolts are evenly arranged around the circumference. The bolt preload ensures a tight fit between flange 10 and the tooling. The connection between mounting plate 5 and the tooling is double-fixed by welding and bolts. The welded part forms a continuous fillet weld with a weld leg height of 6-8mm. After welding, non-destructive testing is performed to ensure there are no welding defects. At the same time, four positioning bolt holes are set around the circumference of mounting plate 5, and secondary reinforcement is carried out by M10 hexagonal socket head cap bolts to prevent mounting plate 5 from shifting or falling off under impact load.

[0036] Mounting discs 5 are fixedly mounted on opposite sides of the first fixture 1 and the second fixture 2. One set of mounting discs 5 is fixedly connected to a mounting ring 6 for mounting the test specimen, and the other set of mounting discs 5 is fixedly connected to an impact disc 7 for impacting the test specimen. The inner diameter of the mounting ring 6 matches the outer diameter of the impact disc 7.

[0037] Here, an axial positioning keyway is provided on the inner wall of the mounting ring 6. The keyway is 8mm wide and 4mm deep, and is adapted to the positioning key on the outer periphery of the test piece to achieve circumferential positioning of the test piece. A layer of polyurethane buffer pad with a thickness of 3-5mm is pasted on the end face of the impact disc 7 facing the mounting ring 6. The buffer pad is made by compression molding and has a Shore hardness of 60-70D. The buffer pad absorbs the peak load at the moment of impact and avoids the concentration of impact stress.

[0038] Furthermore, the dual fixing structure of "welding + bolts" on the mounting plate 5 ensures the connection strength between the mounting plate 5 and the tooling under impact load, avoiding test accidents caused by the mounting plate 5 falling off; the polyurethane buffer pad of the impact plate 7 can absorb a certain amount of peak impact load, reducing impact stress damage to the tooling body and the test piece, and reducing the risk of fragments flying from the broken test piece; the anaerobic adhesive seal and bolt pre-tightening of the flange 10 prevent relative displacement between the flange 10 and the tooling under large loads, ensuring a stable load transmission path, and further improving the safety and reliability of the large load impact test.

[0039] In this invention, firstly, the anaerobic adhesive sealant of the flange 10 and the circumferential bolts are used to fix the first tooling 1 and the second tooling 2 to their corresponding bushings 8, forming a rigid connection. Then, the tooling is stably fixed by adapting the bushings 8 to the external test bench. At the same time, the bearing 4 is fixedly assembled in the placement holes 3 of the first tooling 1 and the second tooling 2. The high-strength pin 9 coaxially passes through the bearing 4 and extends into the bushing 8, constructing a load transfer basic framework of "tooling-bearing-pin-shoulder-test bench". The reinforced material and high strength of the pin 9 provide structural support for bearing large impact loads. Next, one end of the test piece mates with the mounting ring 6 on the mounting plate 5 of the first fixture 1, achieving circumferential positioning of the test piece through the axial positioning keyway on the inner wall of the mounting ring 6. The other end of the test piece fits against the impact plate 7 on the mounting plate 5 of the second fixture 2, ensuring coaxiality between the test piece and the fixture by utilizing the fit between the inner diameter of the mounting ring 6 and the outer diameter of the impact plate 7. During the impact test, an external impact loading device applies an impact load to the impact plate 7. The load is transferred from the impact plate 7 to the test piece, then from the test piece to the mounting ring 6. Subsequently, the first tooling 1 and the second tooling 2 transfer the load to their own placement hole 3 area, then through the bearing 4 to the pin 9. Finally, the pin 9 distributes the load to the bushing 8 and transfers it to the external test bench, forming a complete load transfer path of "impact loading - impact plate 7 - test piece - mounting ring 6 - first tooling 1 / second tooling 2 - placement hole 3 - bearing 4 - pin 9 - bushing 8 - test bench". During the test, if there are installation deviations of the test bench, impact deformation of the test piece, or assembly gaps of tooling components, the bearing 4 can adaptively adjust the relative angles of the first tooling 1, the second tooling 2, and the pin 9 through angular compensation capability. The high-precision coaxial design of the placement hole 3 and the symmetrical center line of the tooling, as well as the positioning keyway limit of the mounting ring 6, further ensure that the test piece is always subjected to coaxial force. At the same time, the polyurethane buffer pad on the end face of the impact plate 7 can absorb part of the peak impact load, and the grease in the bearing 4 reduces component friction loss, together ensuring the accuracy, safety, and stability of the large load impact test.

[0040] The above description of the embodiments is only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. An impact testing fixture, characterized in that: The device includes a first fixture (1) and a second fixture (2) arranged symmetrically. Both the first fixture (1) and the second fixture (2) have placement holes (3). Bearings (4) are fixedly installed in both sets of placement holes (3). Both the first fixture (1) and the second fixture (2) are connected to an external test bench through connectors. Mounting plates (5) are fixedly installed on opposite sides of the first fixture (1) and the second fixture (2). One set of mounting plates (5) is fixedly connected to a mounting ring (6) for mounting the test specimen, and the other set of mounting plates (5) is fixedly connected to an impact plate (7) for impacting the test specimen.

2. The impact testing fixture according to claim 1, characterized in that: The connecting component includes bushings (8) symmetrically arranged on the first tooling (1) and the second tooling (2) for connecting with the test bench. The two sets of bushings (8) are coaxially arranged with the bearings (4) inside the corresponding first tooling (1) and second tooling (2).

3. The impact testing fixture according to claim 2, characterized in that: A pin (9) is coaxially inserted inside the bearing (4), and both ends of the pin (9) extend into the bushing (8) on the corresponding side.

4. The impact testing fixture according to claim 1, characterized in that: The inner diameter of the mounting ring (6) matches the outer diameter of the impact disc (7).

5. The impact testing fixture according to claim 1, characterized in that: A flange (10) is coaxially provided on the first tooling (1) and the second tooling (2) at the corresponding bushing (8). One end of the flange (10) is connected to the first tooling (1) and the second tooling (2), and the other end is fixedly connected to the corresponding bushing (8).

6. The impact testing fixture according to claim 1, characterized in that: The bearing (4) is a radial joint bearing.

7. The impact testing fixture according to claim 3, characterized in that: The pin (9) is made of a high-strength alloy.

8. The impact testing fixture according to claim 2, characterized in that: The bushing (8) is made of 45 steel or 40Cr alloy structural steel.

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