A resonant link fatigue testing apparatus

Abstract

The application discloses a resonant type connecting rod fatigue test device, which comprises a main frame body, a bottom part frame of a vibration exciter is fixed in the middle part of the top surface of the bottom plate of the main frame body, two ends of a first vertical guide rod are installed on the top plate and the bottom plate of the main frame body, two ends of a second vertical limiting rod are installed on the top plate and the bottom plate of the main frame body, a counterweight connecting block is in the middle part of the main frame body, and the first vertical guide rod and the second vertical limiting rod are inserted into left and right through holes of the counterweight connecting block; the actual working condition is more in conformity with the fact, the device has the advantages of simple structure, small size and low cost.

Description

Technical fields:

[0001] This invention relates to the field of fatigue testing equipment technology, and more specifically to a resonant connecting rod fatigue testing device. Background technology:

[0002] Engine connecting rods connect the piston and crankshaft, transmitting the forces acting on the piston to the crankshaft. Therefore, connecting rods are subjected to non-uniform alternating loads from in-cylinder pressure and reciprocating inertial forces, making fatigue fracture their primary failure mode. Consequently, fatigue testing of engine connecting rods is a crucial step in connecting rod development.

[0003] Currently, hydraulic or mechanical loading is commonly used for connecting rod fatigue testing, but it has the following shortcomings:

[0004] The hydraulic cylinders of hydraulic test benches can only apply unidirectional loads, which does not match the alternating loads experienced by the connecting rods during actual operation. Furthermore, the low loading frequency of the cylinders results in long test cycles, high energy consumption, large footprint of auxiliary equipment such as oil tanks, pump stations, and pipelines, and significant vibration and noise during testing.

[0005] Mechanical loading structures are complex, the amplitude of test loads is limited, and energy consumption is high. Summary of the Invention:

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a resonant connecting rod fatigue testing device that is more consistent with actual working conditions and has a simple structure, small size, and low cost.

[0007] The solution of the present invention to the aforementioned technical problem is:

[0008] A resonant linkage fatigue testing device includes a main frame, a bottom frame of an exciter fixed in the middle of the top surface of the bottom plate of the main frame, two ends of a first vertical guide rod installed on the top plate and bottom plate of the main frame, two ends of a second vertical limiting rod installed on the top plate and bottom plate of the main frame, a counterweight connecting block located in the middle of the main frame, and the first vertical guide rod and the second vertical limiting rod inserted into the left and right through holes of the counterweight connecting block.

[0009] The top of the transmission rod at the top of the vibrator presses against the middle of the bottom surface of the counterweight connecting block. Two lower connecting seats are fixed in the middle of the top surface of the counterweight connecting block. An upper horizontal fixing plate is provided below the top plate of the main frame. Two upper connecting seats are fixed in the middle of the bottom surface of the upper horizontal fixing plate. An upper vertical adjusting screw is fixed in the middle of the upper horizontal fixing plate. The top of the upper vertical adjusting screw extends out of the top surface of the upper horizontal fixing plate and passes through the through hole in the middle of the top plate of the main frame. An upper limit nut is screwed to the top of the upper vertical adjusting screw. The bottom surface of the upper limit nut presses against the top surface of the top plate of the main frame. Upper elastic sleeves are installed on the two upper connecting seats and lower elastic sleeves are installed on the two lower connecting seats. The upper and lower mounting through holes of the connecting rod to be tested are fitted with corresponding upper and lower elastic sleeves.

[0010] The inner walls of the left and right ends of the upper and lower elastic sleeves are tapered. Two transverse adjusting screws are respectively inserted into the upper and lower elastic sleeves. An axial threaded through hole is formed in the middle of the end support block. The end support block is threaded into the end of the transverse adjusting screw. The outer wall of the end support block is tapered and presses against the inner wall of the end of the upper or lower elastic sleeve. The outer walls of the upper and lower elastic sleeves press against the inner walls of the corresponding mounting through holes of the upper and lower connecting seats. The middle outer wall of the upper or lower elastic sleeve presses against the inner wall of the corresponding mounting through hole of the connecting rod.

[0011] A connecting rod bushing is fitted on the inner wall of the corresponding mounting through hole of the connecting rod, and the outer wall of the middle part of the upper or lower elastic sleeve is pressed against the inner wall of the corresponding connecting rod bushing.

[0012] The first vertical guide rod is a cylindrical rod, and its outer side wall is close to or in close contact with the inner side wall of the left through hole;

[0013] A vertical guide groove is formed on the inner wall of the left through hole. The top surface of the vertical guide groove extends out of the top surface of the counterweight connecting block. Multiple vertically arranged balls are inserted in the vertical guide groove. An upper annular plate is fixedly connected to the top surface of the counterweight connecting block at the left through hole by bolts. The first vertical guide rod is inserted in the middle through hole of the upper annular plate. The upper annular plate covers the vertical guide groove. All the balls are located at the left through hole and are in close contact with the outer wall of the first vertical guide rod.

[0014] The second vertical limiting rod has multiple vertically extending oblique sidewalls formed on its sidewall, and part of the outer sidewall of the second vertical limiting rod is in close contact with the inner sidewall of the right through hole.

[0015] The top surface of the counterweight connecting block is fixedly connected to the left and right sides by bolts.

[0016] The bottom end of the upper vertical adjusting screw is formed with a spherical part with an outer diameter larger than that of the upper vertical adjusting screw. The middle part of the upper horizontal fixing plate is formed with a vertical screw-in through hole. The inner side wall of the bottom end of the vertical screw-in through hole is a conical wall surface. The upper vertical adjusting screw is screwed into the vertical screw-in through hole, and the upper outer side wall of the spherical part is pressed against the conical wall surface at the bottom of the vertical screw-in through hole.

[0017] The upper horizontal fixing plate has upper vertical guide holes formed on its left and right sides, and the upper parts of the first vertical guide rod and the second vertical limiting rod are inserted into the corresponding upper vertical guide holes.

[0018] The tops of the first vertical guide rod and the second vertical limiting rod are inserted into the corresponding upper vertical through holes formed on the top plate of the main frame. The bottoms of the first vertical guide rod and the second vertical limiting rod are inserted into the corresponding recesses on the top surface of the bottom plate of the main frame. Two positioning connecting seats are fixed on the top surface of the bottom plate of the main frame. The lower parts of the first vertical guide rod and the second vertical limiting rod are inserted into the middle through holes of the corresponding positioning connecting seats. Annular grooves are formed on the lower outer side walls of the first vertical guide rod and the second vertical limiting rod. Multiple radially extending screw-in through holes are formed on the outer side walls of the side plates of the positioning connecting seats. Set bolts are screwed into the corresponding screw-in through holes. The protrusion at the inner end of the set bolt is located in the middle through hole of the positioning connecting seat and inserted into the corresponding annular groove.

[0019] The upper and lower elastic sleeves are metal sleeves with cylindrical outer walls.

[0020] The upper and lower elastic sleeves have multiple left and right cutting grooves formed on their side plates. The left cutting groove extends from the left end of the upper or lower elastic sleeve to the right, and the right cutting groove extends from the right end of the upper or lower elastic sleeve to the left.

[0021] In the upper and lower elastic sleeves, all left and right cutting grooves are spaced apart.

[0022] The outstanding effects of this invention are:

[0023] It utilizes the natural frequency and first mode shape of the test system to apply a small alternating load whose excitation frequency is close to the natural frequency. The test system will then generate a large reciprocating vibration response along the vertical centerline where the center of the two mounting holes of the connecting rod is located. At this time, by adjusting the excitation frequency, the purpose of applying the required load can be achieved.

[0024] Compared with existing technologies, it utilizes the principle of resonance and uses an electromagnetic vibrator as the vibration excitation. During the test, the required test load can be easily obtained by frequency tuning. It has a simple structure and high vibration frequency. At the same time, by adjusting the counterweight connecting block and the counterweight of the connecting block, the vibration load can be made to match the actual operation, making the test more accurate. It has low manufacturing cost and good performance.

[0025] Meanwhile, it is connected to the connecting rod through the upper and lower elastic sleeves, and the connecting bushings of the upper and lower elastic sleeves are locked in place to ensure tight connection. This ensures that the upper and lower elastic sleeves will not collide with the connecting rod during testing, thus ensuring the accuracy of the test. Attached image description:

[0026] Figure 1 This is a partial structural schematic diagram of the present invention;

[0027] Figure 2 This is a partial front view of the present invention;

[0028] Figure 3 This is a partial cross-sectional view of the present invention;

[0029] Figure 4 yes Figure 3 A magnified view of a portion of the image;

[0030] Figure 5 This is a partial cross-sectional view of the present invention at a different angle;

[0031] Figure 6 It is a partial structural diagram of the upper or lower elastic sleeve;

[0032] Figure 7 yes Figure 6 A schematic diagram of the local structure at a different angle;

[0033] Figure 8 This is a partial structural diagram of the connecting bushing;

[0034] Figure 9 This is a partial top view of the present invention;

[0035] Figure 10 This is a partial sectional view of the mounting connector.

[0036] Figure 11 This is a schematic diagram of the finite element analysis simulation of the experiment of this invention;

[0037] Figure 12 This is a schematic diagram of the finite element analysis simulation of the first-order vibration mode of the connecting rod with the first vertical guide rod and the second vertical limiting rod installed.

[0038] Figure 13 This is a schematic diagram of the finite element analysis simulation of the first-order vibration mode of the connecting rod without the first vertical guide rod and the second vertical limit rod installed. Detailed implementation method:

[0039] For example, see below. Figures 1 to 10As shown, a resonant linkage fatigue testing device includes a main frame 200. The bottom frame 301 of the exciter 300 is fixed in the middle of the top surface of the bottom plate of the main frame 200. The two ends of the first vertical guide rod 201 are installed on the top plate and the bottom plate of the main frame 200. The two ends of the second vertical limiting rod 202 are installed on the top plate and the bottom plate of the main frame 200. The counterweight connecting block 60 is located in the middle of the main frame 200. The first vertical guide rod 201 and the second vertical limiting rod 202 are inserted into the left and right through holes of the counterweight connecting block 60.

[0040] The top end of the transmission rod 302 at the top of the vibrator 300 presses against the middle of the bottom surface of the counterweight connecting block 60. The middle of the bottom surface of the counterweight connecting block 60 is formed with a spherical groove, and the top end of the transmission rod 302 is spherical, which presses against the inner wall of the spherical groove. The two cooperate with each other.

[0041] Two lower connecting seats 20 are fixed in the middle of the top surface of the counterweight connecting block 60. An upper horizontal fixing plate 70 is provided below the top plate of the main frame 200. Two upper connecting seats 10 are fixed in the middle of the bottom surface of the upper horizontal fixing plate 70. An upper vertical adjusting screw 71 is fixed in the middle of the upper horizontal fixing plate 70. The top of the upper vertical adjusting screw 71 extends out of the top surface of the upper horizontal fixing plate 70 and passes through the middle through hole of the top plate of the main frame 200. An upper limit nut 72 is screwed to the top of the upper vertical adjusting screw 71. The bottom surface of the upper limit nut 72 presses against the top surface of the top plate of the main frame 200. Upper elastic sleeves 30 are installed on the two upper connecting seats 10, and lower elastic sleeves 40 are installed on the two lower connecting seats 20. The upper and lower mounting through holes of the connecting rod 100 to be tested are fitted with corresponding upper elastic sleeves 30 and lower elastic sleeves 40.

[0042] The inner walls of the left and right ends of the upper elastic sleeve 30 and the lower elastic sleeve 40 are tapered. Two transverse adjusting screws 50 are respectively inserted into the upper elastic sleeve 30 and the lower elastic sleeve 40. The middle part of the end support block 51 is formed with an axial threaded through hole. The end support block 51 is threaded into the end of the transverse adjusting screw 50. The outer wall of the end support block 51 is tapered and presses against the inner wall of the end of the upper elastic sleeve 30 or the lower elastic sleeve 40. The outer walls of the upper elastic sleeve 30 and the lower elastic sleeve 40 press against the inner walls of the corresponding mounting through holes of the upper connecting seat 10 and the lower connecting seat 20. The middle outer wall of the upper elastic sleeve 30 or the lower elastic sleeve 40 presses against the inner wall of the corresponding mounting through hole of the connecting rod 100.

[0043] Furthermore, a connecting rod bushing 101 is fitted onto the inner wall of the corresponding mounting through hole of the connecting rod 100, and the outer wall of the middle part of the upper elastic sleeve 30 or the lower elastic sleeve 40 is pressed against the inner wall of the corresponding connecting rod bushing 101.

[0044] Furthermore, the first vertical guide rod 201 is a cylindrical rod, and its outer side wall is close to or in close contact with the inner side wall of the left through hole.

[0045] A vertical guide groove is formed on the inner wall of the left through hole. The top surface of the vertical guide groove extends out of the top surface of the counterweight connecting block 60. Multiple vertically arranged ball bearings 1 are inserted in the vertical guide groove. The top surface of the counterweight connecting block 60 at the left through hole is fixedly connected to an upper annular plate 2 by bolts. The first vertical guide rod 201 is inserted in the middle through hole of the upper annular plate. The upper annular plate 2 covers the vertical guide groove. All the ball bearings 1 are located at the left through hole and are close to the outer wall of the first vertical guide rod 201.

[0046] Furthermore, the side wall of the second vertical limiting rod 202 is formed with multiple vertically extending oblique side walls, that is, during its processing, the side wall of the second vertical limiting rod 202 is partially beveled to achieve partially oblique side walls.

[0047] Part of the outer wall of the second vertical limiting rod 202 is in close contact with the inner wall of the right through hole.

[0048] The above structure allows the first vertical guide rod 201 to guide the counterweight connecting block 60 when it moves up and down, while the second vertical limiting rod 202 only serves as a limiting function, mainly to prevent the counterweight connecting block 60 from lateral translation. Therefore, the outer side wall forming part is inclined to the side wall to reduce the contact area between it and the inner side wall of the right through hole.

[0049] Furthermore, the first vertical guide rod 201 and the second vertical limiting rod 202 also ensure that the first mode shape of the entire system (the first mode shape refers to the vibration mode of the structure at its lowest natural frequency, i.e., the fundamental frequency. It is the simplest and most basic mode of structural vibration, usually manifested as the uniform vibration of the entire structure) is consistent with the direction of the fatigue test load applied to the connecting rod, that is, the vibration of the connecting rod 100 is along the vertical direction of the center vertical line of the connecting rod 100 (the center line between the center of the upper mounting through hole and the center of the lower mounting through hole of the connecting rod 100), such as... Figure 12 Without the first vertical guide rod 201 and the second vertical limiting rod 202, the vibration direction of the connecting rod 100 will be tilted, resulting in a test structure that is not what is required and reducing accuracy. Figure 13 .

[0050] Furthermore, the top left and right sides of the counterweight connecting block 60 are both fixedly connected to connecting counterweight blocks 61 by bolts. The connecting counterweight blocks 61 are arc-shaped blocks. This connecting counterweight block 61 can be increased or decreased according to the test requirements, thereby changing the total amount between the counterweight connecting block 60 and the connecting counterweight block 61 to meet the test load requirements.

[0051] The bottom end of the upper vertical adjusting screw 71 is formed with a spherical part with an outer diameter larger than that of the upper vertical adjusting screw 71. The middle part of the upper horizontal fixing plate 70 is formed with a vertical screw-in through hole. The inner side wall of the bottom end of the vertical screw-in through hole is a conical wall surface. The upper vertical adjusting screw 71 is screwed into the vertical screw-in through hole, and the upper outer side wall of the spherical part is pressed against the conical wall surface at the bottom of the vertical screw-in through hole.

[0052] The upper horizontal fixing plate 70 has upper vertical guide through holes formed on its left and right sides. The upper parts of the first vertical guide rod 201 and the second vertical limiting rod 202 are inserted into the corresponding upper vertical guide through holes.

[0053] The tops of the first vertical guide rod 201 and the second vertical limiting rod 202 are engaged in the corresponding upper vertical through holes formed on the top plate of the main frame 200. The bottoms of the first vertical guide rod 201 and the second vertical limiting rod 202 are inserted into the corresponding recesses on the top surface of the bottom plate of the main frame 200, and their outer walls press against the inner walls of the corresponding recesses on the top surface of the bottom plate of the main frame 200. Two positioning connecting seats 80 are fixed on the top surface of the bottom plate of the main frame 200. The lower parts of the first vertical guide rod 201 and the second vertical limiting rod 202 are inserted into the middle through hole of the corresponding positioning connecting seat 80. The lower outer side wall of the first vertical guide rod 201 and the second vertical limiting rod 202 is formed with an annular groove. The outer side wall of the side plate of the positioning connecting seat 80 is formed with multiple radially extending screw through holes. The set bolt 81 is screwed into the corresponding screw through hole. The protrusion at the inner end of the set bolt 81 is located in the middle through hole of the positioning connecting seat 80 and inserted into the corresponding annular groove.

[0054] It uses a positioning connector 80 and a set bolt 81 to limit the bottom of the first vertical guide rod 201 and the second vertical limit rod 202, preventing the first vertical guide rod 201 and the second vertical limit rod 202 from disengaging from the bottom recess, and further achieving limiting and fixing.

[0055] Furthermore, the upper connecting seat 10 includes an upper fixed connecting block 11 and an upper connecting block 12 fixed to the bottom surface of the upper fixed connecting block 11 by bolts. The upper fixed connecting block 11 is fixed to the middle of the bottom surface of the upper horizontal fixed plate 70. An upper semi-circular groove is formed in the middle of the bottom surface of the upper fixed connecting block 11, and a lower semi-circular groove is formed in the middle of the top surface of the upper connecting block 12. The upper semi-circular groove and the lower semi-circular groove form a mounting through hole. The end of the upper elastic sleeve 30 is inserted into the mounting through hole, and its outer side wall is pressed against the inner side wall of the corresponding mounting through hole.

[0056] The lower connecting seat 20 includes a lower fixed connecting block 21 and a lower connecting block 22 fixed to the top surface of the lower fixed connecting block 21 by bolts. The bottom surface of the lower fixed connecting block 21 is fixed to the middle of the top surface of the counterweight connecting block 60. A first lower semi-circular groove is formed in the middle of the top surface of the lower fixed connecting block 21, and a second lower semi-circular groove is formed in the middle of the bottom surface of the lower connecting block 22. The first lower semi-circular groove and the second lower semi-circular groove form an installation through hole. The end of the lower elastic sleeve 40 is inserted into the installation through hole of the lower connecting seat 20, and its outer side wall is pressed against the inner side wall of the corresponding installation through hole.

[0057] The upper and lower mounting through holes of the connecting rod 100 to be tested are fitted with corresponding upper elastic sleeves 30 and lower elastic sleeves 40; the inner sidewall of the corresponding mounting through hole of the connecting rod 100 is fixed by interference fit with a connecting rod bushing 101; the middle outer sidewall of the upper elastic sleeve 30 or the lower elastic sleeve 40 is pressed against the inner sidewall of the corresponding connecting rod bushing 101; and a lubrication groove is formed on the inner sidewall of the connecting rod bushing 101.

[0058] Furthermore, the outer end of the end support block 51 is formed with an outwardly protruding rotating part, and the outer end of the axially threaded through hole extends out of the outer end face of the rotating part.

[0059] Furthermore, the upper elastic sleeve 30 and the lower elastic sleeve 40 are metal sleeves with cylindrical outer walls;

[0060] The upper elastic sleeve 30 and the lower elastic sleeve 40 have multiple left cutting grooves 31 and right cutting grooves 32 formed on their side plates. The left cutting groove 31 extends from the left end of the upper elastic sleeve 30 or the lower elastic sleeve 40 to the right, and the right cutting groove 32 extends from the right end of the upper elastic sleeve 30 or the lower elastic sleeve 40 to the left.

[0061] Furthermore, in the upper elastic sleeve 30 and the lower elastic sleeve 40, all the left cutting grooves 31 and right cutting grooves 32 are arranged at intervals.

[0062] Furthermore, both the upper elastic sleeve 30 and the lower elastic sleeve 40 are formed with three left cutting grooves 31 and three right cutting grooves 32. The three left cutting grooves 31 are evenly distributed on the upper elastic sleeve 30 or the lower elastic sleeve 40 with the central axis of the upper elastic sleeve 30 or the lower elastic sleeve 40 as the center, and the three right cutting grooves 32 are evenly distributed on the upper elastic sleeve 30 or the lower elastic sleeve 40 with the central axis of the upper elastic sleeve 30 or the lower elastic sleeve 40 as the center.

[0063] Figure 11 This is a schematic diagram of the finite element analysis simulation of the experiment in this embodiment.

[0064] In this embodiment, during installation, the middle portions of the upper elastic sleeve 30 and the lower elastic sleeve 40 are first inserted into the connecting bushing 101 at the corresponding mounting through hole of the connecting rod 100. Then, the two ends of the upper elastic sleeve 30 and the lower elastic sleeve 40 are inserted into the mounting through holes of the corresponding upper connecting seat 10 and the corresponding lower connecting seat 20. Two lateral adjusting screws 50 are respectively inserted into the upper elastic sleeve 30 and the lower elastic sleeve 40. The end support block 51 is screwed into the end of the lateral adjusting screw 50. The rotating end support block 51 is rotated by rotating the rotating end face formed in the middle of its outer end face. The end support block 51 rotates, causing its outer side wall to press against the inner side wall at the end of the upper elastic sleeve 30 or the lower elastic sleeve 40. As the end support block 51 moves inward, the outer side walls of the upper elastic sleeve 30 and the lower elastic sleeve 40 are pushed outward, pressing against the inner side walls of the corresponding mounting through holes of the upper connecting seat 10 and the lower connecting seat 20. The middle outer side wall of the upper elastic sleeve 30 or the lower elastic sleeve 40 presses against the inner side wall of the connecting bushing 101 of the corresponding mounting through hole of the connecting rod 100, thus achieving a locking and fixing.

[0065] After installation, this structure ensures a tight connection between the inner wall of the connecting bushing 101 of the connecting rod 100 and the outer wall of the upper elastic sleeve 30 or lower elastic sleeve 40, eliminating gaps and preventing impact loads during subsequent tests, thus ensuring test accuracy. This is because fatigue testing machines cannot accurately reproduce the actual operating conditions of the connecting rod and cannot form a lubricating oil film to reduce impact loads on the hole / shaft clearance, potentially leading to abnormal failures. To address this issue, adjustable upper elastic sleeve 30 and lower elastic sleeve 40 are used to eliminate gaps, preventing erroneous test results and ensuring test accuracy.

[0066] Meanwhile, as needed, corresponding counterweight blocks 61 of the same weight are fixedly connected to the left and right sides of the top surface of the counterweight connecting block 60 by bolts to meet the load requirements, thereby changing the vibration frequency of the transmission rod 302.

[0067] The specific method is as follows: During the test, strain gauges (which are existing known components and will not be described in detail here) are attached to the body of the connecting rod 100. The frequency of the exciter 300 is adjusted, for example, from 200 Hz upwards. At this time, the counterweight block 61 is not fixedly connected to the top surface of the counterweight connecting block 60. The strain gauge values ​​are observed (the strain gauges are electrically connected to the control host via electrical connection wires, and the corresponding values ​​are displayed on the display screen of the control host). When the value rises rapidly, it indicates that the frequency of the exciter 300 is close to or equal to the natural frequency of the whole system in this embodiment. At this time, the test can be carried out. During this process, the connecting rod 100 experiences fatigue failure, that is, crack initiation and rapid propagation occur. At this time, the stiffness of the test system changes, and the natural frequency also changes accordingly. The system acceleration will be significantly different from that before failure. When this difference reaches the specified limit, the test ends, and a life-load value is obtained as the result of this test. When the test reaches 5x10 6 The test ends if the connecting rod 100 does not fail during the specified number of cycles.

[0068] Then, the next round of testing is conducted, this time requiring a change in the load applied to connecting rod 100. The weight of counterweight 61 is altered, thus changing the overall natural frequency. The frequency of the exciter 300 is adjusted while the stress value is observed. When the stress value rises sharply, it indicates that the system frequency is approaching the frequency of the exciter 300, thus achieving resonance. This stress value represents the load applied to connecting rod 100, and the test can then be conducted. The test procedure is the same as above and will not be detailed further.

[0069] By changing the frequency of the vibrator 300 and the number of connected counterweights 61, and measuring the rapid change in strain value of the connecting rod 100 using strain gauges, it is confirmed that the frequency adjustment is complete, and the test can be conducted. The aforementioned process is repeated to perform fatigue tests and obtain the results of the next test. This process is repeated until the test points of the connecting rod 100 that meet the confidence level are obtained. The fatigue limit results of the test are obtained by statistically analyzing the life-load values ​​of all failed specimens.

[0070] Finally, it should be noted that the above embodiments are merely representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments and many variations are possible. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention should be considered within the protection scope of the present invention.

Claims

1. A resonant linkage fatigue testing device, comprising a main frame (200), characterized in that: The bottom frame (301) of the vibrator (300) is fixed in the middle of the top surface of the bottom plate of the main frame (200). The two ends of the first vertical guide rod (201) are installed on the top plate and bottom plate of the main frame (200). The two ends of the second vertical limiting rod (202) are installed on the top plate and bottom plate of the main frame (200). The counterweight connecting block (60) is located in the middle of the main frame (200). The first vertical guide rod (201) and the second vertical limiting rod (202) are inserted into the left and right through holes of the counterweight connecting block (60). The top end of the transmission rod (302) at the top of the vibrator (300) presses against the middle of the bottom surface of the counterweight connecting block (60). Two lower connecting seats (20) are fixed in the middle of the top surface of the counterweight connecting block (60). An upper horizontal fixing plate (70) is provided below the top plate of the main frame (200). Two upper connecting seats (10) are fixed in the middle of the bottom surface of the upper horizontal fixing plate (70). An upper vertical adjusting screw (71) is fixed in the middle of the upper horizontal fixing plate (70). The top of the upper vertical adjusting screw (71) extends out of the upper horizontal fixing plate. The top surface of the upper vertical adjusting screw (71) passes through the middle through hole of the top plate of the main frame (200). The top of the upper vertical adjusting screw (71) is screwed with an upper limit nut (72). The bottom surface of the upper limit nut (72) presses against the top surface of the top plate of the main frame (200). The upper elastic sleeve (30) is installed on the two upper connecting seats (10), and the lower elastic sleeve (40) is installed on the two lower connecting seats (20). The upper and lower mounting through holes of the connecting rod (100) to be tested are fitted with corresponding upper elastic sleeves (30) and lower elastic sleeves (40). The inner walls of the left and right ends of the upper elastic sleeve (30) and the lower elastic sleeve (40) are tapered. Two transverse adjusting screws (50) are respectively inserted into the upper elastic sleeve (30) and the lower elastic sleeve (40). The middle part of the end support block (51) is formed with an axial screw-in through hole. The end support block (51) is screwed into the end of the transverse adjusting screw (50). The outer wall of the end support block (51) is tapered. It presses against the inner wall of the end of the upper elastic sleeve (30) or the lower elastic sleeve (40). The outer walls of the upper elastic sleeve (30) and the lower elastic sleeve (40) press against the inner walls of the corresponding mounting through holes of the upper connecting seat (10) and the lower connecting seat (20). The middle outer wall of the upper elastic sleeve (30) or the lower elastic sleeve (40) presses against the inner wall of the corresponding mounting through hole of the connecting rod (100).

2. The resonant connecting rod fatigue testing device according to claim 1, characterized in that: A connecting rod bushing (101) is fitted on the inner wall of the corresponding mounting through hole of the connecting rod (100), and the middle outer wall of the upper elastic sleeve (30) or the lower elastic sleeve (40) presses against the inner wall of the corresponding connecting rod bushing (101).

3. The resonant connecting rod fatigue testing device according to claim 1, characterized in that: The first vertical guide rod (201) is a cylindrical rod, and its outer side wall is close to or in close contact with the inner side wall of the left through hole; A vertical guide groove is formed on the inner wall of the left through hole. The top surface of the vertical guide groove extends out of the top surface of the counterweight connecting block (60). Multiple vertically arranged ball bearings (1) are inserted in the vertical guide groove. The top surface of the counterweight connecting block (60) at the left through hole is fixedly connected to an upper annular plate (2) by bolts. The first vertical guide rod (201) is inserted in the middle through hole of the upper annular plate. The upper annular plate (2) covers the vertical guide groove. All the ball bearings (1) are located at the left through hole and are close to the outer wall of the first vertical guide rod (201).

4. The resonant connecting rod fatigue testing device according to claim 1, characterized in that: The second vertical limiting rod (202) has multiple vertically extending oblique sidewalls formed on its sidewalls, and part of the outer sidewall of the second vertical limiting rod (202) is in close contact with the inner sidewall of the right through hole.

5. The resonant connecting rod fatigue testing device according to claim 1, characterized in that: The top surface of the counterweight connecting block (60) is fixedly connected to the left and right sides by bolts with connecting counterweight blocks (61).

6. The resonant connecting rod fatigue testing device according to claim 1, characterized in that: The bottom end of the upper vertical adjusting screw (71) is formed with a spherical part with an outer diameter larger than that of the upper vertical adjusting screw (71). The middle part of the upper horizontal fixing plate (70) is formed with a vertical screw-in through hole. The inner side wall of the bottom end of the vertical screw-in through hole is a conical wall surface. The upper vertical adjusting screw (71) is screwed into the vertical screw-in through hole. The upper outer side wall of the spherical part is pressed against the conical wall surface at the bottom of the vertical screw-in through hole.

7. The resonant connecting rod fatigue testing device according to claim 1, characterized in that: The upper horizontal fixing plate (70) has upper vertical guide through holes formed on its left and right sides. The upper parts of the first vertical guide rod (201) and the second vertical limiting rod (202) are inserted into the corresponding upper vertical guide through holes. The tops of the first vertical guide rod (201) and the second vertical limiting rod (202) are installed in corresponding upper vertical through holes formed on the top plate of the main frame (200). The bottoms of the first vertical guide rod (201) and the second vertical limiting rod (202) are inserted into corresponding recesses on the top surface of the bottom plate of the main frame (200). Two positioning connecting seats (80) are fixed on the top surface of the bottom plate of the main frame (200). 2) The lower part of the sleeve is inserted into the middle through hole of the corresponding positioning connector (80). The lower outer side wall of the first vertical guide rod (201) and the second vertical limit rod (202) is formed with an annular groove. The outer side wall of the side plate of the positioning connector (80) is formed with multiple radially extending screw through holes. The set bolt (81) is screwed into the corresponding screw through hole. The protrusion of the inner end of the set bolt (81) is in the middle through hole of the positioning connector (80) and inserted into the corresponding annular groove.

Images