CN114993863B - Metal fatigue resistance detection device - Google Patents

Abstract

The invention discloses a metal fatigue resistance performance detection device, comprising a base and a fixture assembly and a detection assembly respectively arranged on the base; an inverted "U"-shaped frame is arranged on the base; the detection assembly comprises a driving motor, a motor side crank, a planetary gear, an inner gear ring, a gear side crank, a connecting rod, a piston, a guide seat, a mounting rod and a hammer head, wherein the output shaft of the driving motor is fixedly connected to the motor side crank, one end of the motor side crank is rotatably connected to the axis of the planetary gear, the planetary gear is meshed with the inner gear ring, one end of the gear side crank is fixedly connected to the axis of the planetary gear, the other end of the gear side crank is rotatably connected to one end of the connecting rod, a first sliding groove arranged along the vertical center line of the inner gear ring is opened on one side of the guide seat, the piston is slidably arranged in the first sliding groove, the other end of the connecting rod passes through the lateral wall of the "U"-shaped frame and is rotatably connected to the top of the piston, the bottom of the piston is fixedly connected to the mounting rod, and the bottom of the mounting rod is fixedly connected to the hammer head.

Description

Metal fatigue resistance testing device

Technical Field

The invention relates to the technical field of metal detection, in particular to a metal anti-fatigue performance detection device.

Background technique

Metal fatigue refers to the process in which materials and components gradually produce local permanent cumulative damage in one or several places under cyclic stress or cyclic strain, and cracks or sudden complete fractures occur after a certain number of cycles. When materials and structures are subjected to repeated changing loads, even if the stress value does not exceed the strength limit of the material, or even lower than the elastic limit, damage may occur. This phenomenon of material and structure damage under repeated alternating loads is called metal fatigue failure.

Therefore, for production safety, it is often necessary to test the fatigue resistance of metal pipes. At present, most commonly used fatigue resistance testing devices use a simple crank structure to drive a hammer to hammer the metal pipe, that is, the crank drives the connecting rod and the piston drives the hammer. However, the simple structure of directly driving the connecting rod and the piston to drive the hammer is prone to generate radial force at the piston, which not only causes greater vibration of the device, but also easily leads to excessive errors in the test results.

Summary of the invention

In order to solve the problems existing in the prior art, the present invention provides a metal fatigue resistance performance detection device.

The technical solution adopted by the present invention is:

A metal fatigue resistance testing device comprises a base and a clamp assembly for fixing a metal pipe and a testing assembly for testing force applied to the metal pipe, which are respectively arranged on the base; an inverted "U"-shaped frame is provided on the base, and the bottom ends of the two longitudinal walls of the "U"-shaped frame are fixedly connected to the top of the base; the testing assembly comprises a driving motor, a motor side crank, a planetary gear, an inner gear ring, a gear side crank, a connecting rod, a piston, a guide seat, a mounting rod and a hammer head, the driving motor is fixedly arranged on the top of the transverse wall of the "U"-shaped frame, the inner gear ring is fixedly arranged on the top of the transverse wall of the "U"-shaped frame and is located on one side of the output shaft of the driving motor, the output shaft of the driving motor is fixedly connected to the motor side crank, one end of the motor side crank is rotatably connected to the axis of the planetary gear, the planetary gear is meshingly connected to the inner gear ring, and the One end of the gear side crank is fixedly connected to the axis of the planetary gear, and the other end of the gear side crank is rotatably connected to one end of the connecting rod, the diameter of the inner gear ring is twice the diameter of the planetary gear, and the rotation axis of the connecting rod rotatably connected to the gear side crank is located on the pitch circle of the planetary gear. The guide seat is vertically fixed to the bottom of the transverse wall of the "U"-shaped frame, and one side of the guide seat is provided with a first sliding groove arranged along the vertical center line of the inner gear ring. The piston is slidably arranged in the first sliding groove, and the other end of the connecting rod passes through the transverse wall of the "U"-shaped frame and is rotatably connected to the top of the piston. The transverse wall of the "U"-shaped frame is provided with a clearance hole that cooperates with the connecting rod, and the bottom of the piston is fixedly connected to the mounting rod, and the bottom of the mounting rod is fixedly connected to the hammer head; the clamp assembly is fixedly arranged on the top of the base and is located below the hammer head.

Preferably, the clamp assembly includes a mounting seat, a fixed block, a sliding block and a clamp, the mounting seat is fixedly arranged on the top of the base, a second sliding groove is opened on the top of the mounting seat, the fixed block is fixedly arranged at one end of the second sliding groove, the sliding block is slidably arranged at the other end of the second sliding groove, and clamps are respectively provided on opposite sides of the fixed block and the sliding block.

Preferably, a screw rod is provided in the second slide groove, one end of the screw rod is rotatably connected to the lower part of the fixed block, the other end of the screw rod is threadedly connected to the lower part of the sliding block and passes through the side wall of the mounting seat and extends to the outside of the mounting seat, the other end of the screw rod is rotatably connected to the mounting seat, and the part of the other end of the screw rod exposed outside the mounting seat is fixedly connected to a handle.

Preferably, the clamp includes a chuck, a clamping plate and a clamping column, one side of the chuck is rotatably connected to the fixed block and the side opposite to the sliding block through a rotating shaft, one end of the rotating shaft on the chuck corresponding to the fixed block passes through the fixed block and is transmission-connected to the output shaft of the driving motor through a transmission assembly, a plurality of clamping columns arranged along the radial direction of the chuck are evenly distributed through the side wall of the chuck, the clamping column is slidingly connected to the side wall of the chuck, one end of the clamping column located on the inner side of the chuck is fixedly connected to the clamping plate, and one end of the clamping column located on the outer side of the chuck is fixedly connected to a baffle, and a spring is connected between the baffle and the side wall of the chuck.

Preferably, the transmission assembly includes a worm wheel, a transmission shaft, a driving bevel gear and a driven bevel gear, a part of the output shaft of the drive motor is a worm, the worm wheel is meshingly connected to the worm, the top end of the transmission shaft is fixedly connected to the axis of the worm wheel, the bottom end of the transmission shaft passes through the lateral wall of the "U"-shaped frame and is rotatably connected to the lateral wall of the "U"-shaped frame, the bottom end of the transmission shaft is fixedly connected to the driving bevel gear, the driving bevel gear is meshingly connected to the driven bevel gear, and one end of the rotating shaft corresponding to the fixed block is fixedly connected to the axis of the driven bevel gear.

Preferably, the driven bevel gear, the rotating shaft, the axial center of the chuck and the corresponding positions of the fixed block and the sliding block are provided with interconnected through cavities, the inner side wall of the cavity is provided with an internal thread, the cavity thread is connected to a threaded rod, one end of the threaded rod extends into the chuck and is fixedly connected to a conical chuck, and the other end of the threaded rod extends out of the cavity and is fixedly connected to a handle.

Preferably, the bottom of the hammer head is rotatably connected to a roller.

Preferably, a film pressure sensor is provided between the hammer head and the mounting rod, a display screen is fixedly provided on the base, and the film pressure sensor is connected to the display screen via a wire signal.

The beneficial effects of the present invention are:

1. The driving motor drives the connecting rod to drive the hammer to hammer the metal pipe to complete the detection through the motor side crank in cooperation with the inner gear ring, planetary gear and gear side crank. Since the diameter of the inner gear ring is twice the diameter of the planetary gear, the rotation axis of the connecting rod and the gear side crank is located on the pitch circle of the planetary gear, so the connecting rod will move up and down along the vertical center line of the inner gear ring, so as not to generate radial force on the piston, which can reduce vibration and improve detection accuracy;

2. The metal pipe is fixed by a clamp. The distance between the sliding block and the fixed block can be adjusted to adapt to metal pipes of different lengths, which is also convenient for installing the metal pipe;

3. The same driving motor is used to drive the hammer to hammer the metal pipe and drive the metal pipe to rotate at the same time, which reduces the cost of the device;

4. For metal pipes with larger diameters, they can be clamped from the outside through the clamping plate, and for metal pipes with smaller diameters, they can be clamped from the inside through the conical chuck, which has a wide range of applications.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the structure and working process of an existing commonly used crank-connecting rod mechanism;

FIG2 is a schematic diagram of the front view of the structure of an embodiment of the present invention;

FIG3 is a schematic diagram of the right side structure of the detection component in an embodiment of the present invention;

FIG4 is a schematic diagram of the front view structure and working process of the clamp assembly in an embodiment of the present invention;

: 1. crank, 2. connecting rod, 3. piston, 4. base, 5. "U"-shaped frame, 6. driving motor, 7. motor side crank, 8. planetary gear, 9. inner ring gear, 10. gear side crank, 11. connecting rod, 12. piston, 13. guide seat, 14. mounting rod, 15. hammer head, 16. mounting seat, 17. fixed block, 18. sliding block, 19. screw, 20. handle, 21. chuck, 22. splint, 23. clamping column, 24. rotating shaft, 25. baffle, 26. spring, 27. first bevel gear, 28. second bevel gear, 29. transmission shaft, 30. active bevel gear, 31. driven bevel gear, 32. threaded rod, 33. conical chuck, 34. roller, 35. film pressure sensor, 36. display screen.

Detailed ways

The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

Example

As shown in FIG2 , a metal fatigue resistance testing device comprises a base 4 and a clamp assembly for fixing a metal pipe and a testing assembly for testing the force applied to the metal pipe, which are respectively arranged on the base 4; an inverted "U"-shaped frame 5 is provided on the base 4, and the bottom ends of the two longitudinal walls of the "U"-shaped frame 5 are fixedly connected to the top of the base 4; the testing assembly comprises a driving motor 6, a motor side crank 7, a planetary gear 8, an inner gear ring 9, a gear side crank 10, a connecting rod 11, a piston 12, a guide seat 13, a mounting rod 14 and a hammer head 15, the driving motor 6 is fixedly arranged on the top of the transverse wall of the "U"-shaped frame 5, the inner gear ring 9 is fixedly arranged on the top of the transverse wall of the "U"-shaped frame 5 and is located on one side of the output shaft of the driving motor 6, the output shaft of the driving motor 6 is fixedly connected to the motor side crank 7, one end of the motor side crank 7 is rotatably connected to the axis of the planetary gear 8, the planetary gear 8 is meshed with the inner gear ring 9, and the gear One end of the wheel side crank 10 is fixedly connected to the axis of the planetary gear 8, and the other end of the gear side crank 10 is rotatably connected to one end of the connecting rod 11. The diameter of the inner gear ring 9 is twice the diameter of the planetary gear 8. The rotation axis of the connecting rod 11 rotatably connected to the gear side crank 10 is located on the pitch circle of the planetary gear 8. The guide seat 13 is vertically fixed at the bottom of the horizontal wall of the "U"-shaped frame 5. One side of the guide seat 13 is provided with a first sliding groove arranged along the vertical center line of the inner gear ring 9. The piston 12 is slidably arranged in the first sliding groove. The other end of the connecting rod 11 penetrates the horizontal wall of the "U"-shaped frame 5 and is rotatably connected to the top of the piston 12. The horizontal wall of the "U"-shaped frame 5 is provided with a clearance hole that cooperates with the connecting rod 11. The bottom of the piston 12 is fixedly connected to the mounting rod 14, and the bottom of the mounting rod 14 is fixedly connected to the hammer head 15; the clamp assembly is fixedly arranged on the top of the base 4 and is located below the hammer head 15.

As shown in FIG1 , in a conventional crank 1 and connecting rod 2 mechanism, one end of the crank 1 is fixed, and the other end performs circular motion to drive one end of the connecting rod 2, thereby driving the other end of the connecting rod 2 to perform linear motion. The linear motion path of the piston 3 is used as the center line, and the position of one end of the connecting rod 2 alternates between the two sides of the center line. When there is an angle between the connecting rod 2 and the center line, a radial force is generated on the piston 3. The alternating positive and negative directions of the force will generate vibration, and will also cause part of the energy provided by the crank 1 to be consumed ineffectively.

The present invention improves the crank-connecting rod mechanism by providing an inner ring gear 9 and a planetary gear 8, wherein the diameter of the inner ring gear 9 is twice the diameter of the planetary gear 8, and one end of the gear-side crank 10 is fixedly connected to the axis of the planetary gear 8, and the rotation axis of the connecting rod 11 and the gear-side crank 10 is rotatably connected is located on the pitch circle of the planetary gear 8, and when the axis of the planetary gear 8 and the axis of the inner ring gear 9 are located in the same horizontal plane, the rotation axis of the connecting rod 11 and the gear-side crank 10 is rotatably connected is located at the center of the inner ring gear 9. Therefore, when the driving motor 6 drives the planetary gear 8 to rotate in the inner gear ring 9 through the motor side crank 7, the rotation axis of the connecting rod 11 and the gear side crank 10 connected to each other moves up and down along the vertical center line of the inner gear ring 9. Since the other end of the connecting rod 11 and the piston 12 also move up and down along the vertical center line of the inner gear ring 9, the connecting rod 11 as a whole will move up and down along the vertical center line of the inner gear ring 9, which greatly reduces the radial force generated at the piston 12, thereby greatly reducing vibration and reducing the ineffective consumption of the energy of the driving motor 6. The present invention drives the hammer head 15 to hammer the metal pipe fixed by the clamp assembly through the improved crank-connecting rod mechanism to complete the fatigue resistance test of the metal material, and the whole device has good vibration reduction effect and high energy utilization rate. In order to balance the weight on both sides of the motor side crank 7 and further reduce vibration, a counterweight block can also be set at the other end of the motor side crank 7 relative to the planetary gear 8, and the weight of the counterweight block is suitable to meet the load matching of the two ends of the motor side crank 7.

In one embodiment, the clamp assembly includes a mounting seat 16, a fixed block 17, a sliding block 18 and a clamp, the mounting seat 16 is fixedly arranged on the top of the base 4, a second slide groove is opened on the top of the mounting seat 16, the fixed block 17 is fixedly arranged at one end of the second slide groove, the sliding block 18 is slidably arranged at the other end of the second slide groove, and clamps are respectively provided on the opposite sides of the fixed block 17 and the sliding block 18.

The metal pipe is fixed by two clamps on the fixed block 17 and the sliding block 18. The sliding block 18 can be moved to adjust the distance between it and the fixed block 17, which not only facilitates the installation of the metal pipe into the two clamps, but also can adapt to metal pipes of different lengths.

In one embodiment, a screw rod 19 is provided in the second slide groove, one end of the screw rod 19 is rotatably connected to the lower part of the fixed block 17, the other end of the screw rod 19 is threadedly connected to the lower part of the sliding block 18 and passes through the side wall of the mounting seat 16 to extend to the outside of the mounting seat 16, the other end of the screw rod 19 is rotatably connected to the mounting seat 16, and the other end of the screw rod 19 exposed outside the mounting seat 16 is fixedly connected to a handle 20. The position of the sliding block 18 can be moved by rotating the screw rod 19 by the handle 20.

In one embodiment, the clamp includes a chuck 21, a clamping plate 22 and a clamping column 23. One side of the chuck 21 is rotatably connected to the side opposite to the fixed block 17 and the sliding block 18 through a rotating shaft 24. One end of the rotating shaft 24 on the chuck 21 corresponding to the fixed block 17 passes through the fixed block 17 and is transmission-connected to the output shaft of the driving motor 6 through a transmission assembly. A plurality of clamping columns 23 arranged along the radial direction of the chuck 21 are evenly distributed through the side wall of the chuck 21. The clamping columns 23 are slidingly connected to the side wall of the chuck 21. The end of the clamping column 23 located on the inner side of the chuck 21 is fixedly connected to the clamping plate 22. The end of the clamping column 23 located on the outer side of the chuck 21 is fixedly connected to a baffle 25. A spring 26 is connected between the baffle 25 and the side wall of the chuck 21.

When fixing the metal tube, first move the sliding block 18 so that there is a sufficient distance between it and the fixed block 17, pull out the clamping column 23 on the clamping disc 21 of the fixed block 17, and the setting of the baffle 25 can facilitate pulling the clamping column 23, then put one end of the metal tube into the clamping disc 21 of the fixed block 17, and then release the clamping column 23, then pull out the clamping column 23 on the clamping disc 21 of the sliding block 18, move the sliding block 18 toward the fixed block 17, so that the other end of the metal tube enters the clamping disc 21 of the sliding block 18, and finally release the clamping column 23 on the clamping disc 21 of the sliding block 18, and fix the metal tube by pressing the clamping plate 22 with the spring 26.

In one embodiment, the transmission assembly includes a worm wheel, a transmission shaft 29, a driving bevel gear 30 and a driven bevel gear 31. A part of the output shaft of the drive motor 6 is a worm, and the worm wheel is meshingly connected to the worm. The top end of the transmission shaft 29 is fixedly connected to the axis of the worm wheel, and the bottom end of the transmission shaft 29 passes through the lateral wall of the "U"-shaped frame 5 and is rotatably connected to the lateral wall of the "U"-shaped frame 5. The bottom end of the transmission shaft 29 is fixedly connected to the driving bevel gear 30, and the driving bevel gear 30 is meshingly connected to the driven bevel gear 31. One end of the rotating shaft 24 corresponding to the fixed block 17 is fixedly connected to the axis of the driven bevel gear 31.

The transmission assembly drives the hammer 15 and the metal tube to rotate at the same time when the output shaft of the driving motor 6 drives the hammer 15, so as to achieve hammering of different positions of the metal tube, avoid hammering of the hammer 15 at the same place all the time, improve detection accuracy, save power source and save cost. The first bevel gear 27 on the output shaft of the driving motor 6 drives the second bevel gear 28 to rotate, and then drives the transmission shaft 29, the driving bevel gear 30 and the driven bevel gear 31, and finally drives the rotating shaft 24 and the chuck 21 on the fixed block 17 to rotate, so as to achieve the rotation of the metal tube.

In one of the embodiments, the driven bevel gear 31, the rotating shaft 24, the axis of the chuck 21, and the corresponding positions of the fixed block 17 and the sliding block 18 are provided with interconnected through cavities, the inner side wall of the cavity is provided with an internal thread, the cavity is threadedly connected to a threaded rod 32, one end of the threaded rod 32 extends into the chuck 21 and is fixedly connected to a conical chuck 33, and the other end of the threaded rod 32 extends out of the cavity and is fixedly connected to a handle 20.

The threaded rod 32 connected by the inner thread of the cavity is used to adjust the position of the tapered chuck 33. When the outer diameter of the metal tube is small, the clamping plates 22 may be unable to completely clamp the metal tube due to mutual obstruction. In this case, the metal tube can be fixed from the inside by the tapered chuck 33. When the tapered chuck 33 is needed, the sliding block 18 is first moved to have a sufficient distance between it and the fixed block 17, and the threaded rod 32 on one side of the fixed block 17 is rotated by the handle 20 to extend the tapered chuck 33, and one end of the metal tube is sleeved on the tapered chuck 33 on one side of the fixed block 17, and then the threaded rod 32 on one side of the sliding block 18 is rotated by the handle 20 to extend the tapered chuck 33, and then the sliding block 18 is moved toward the fixed block 17, so that the tapered chuck 33 on one side of the sliding block 18 enters the other end of the metal tube and fixes the metal tube.

In one embodiment, a roller 34 is rotatably connected to the bottom of the hammer head 15 .

The roller 34 can reduce the conversion of the hammering force of the hammer head 15 into friction force during the rotation of the metal pipe, thereby improving the detection accuracy.

In one embodiment, a film pressure sensor 35 is provided between the hammer head 15 and the mounting rod 14, a display screen 36 is fixedly provided on the base 4, and the film pressure sensor 35 and the display screen 36 are connected via wire signals.

The hammer head 15 continuously hammers the metal rod to cause bending fatigue failure of the metal rod, and the film pressure sensor 35 can measure the maximum radial load that the metal rod can withstand. The hammering force of the hammer head 15 can be adjusted by the driving motor 6. Changing the hammering speed of the hammer head 15 can change the hammering force. The data measured by the film pressure sensor 35 can be displayed on the display.

The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims (8)

1. A metal fatigue resistance testing device, characterized in that it comprises a base (4) and a clamp assembly for fixing a metal pipe and a testing assembly for testing the force applied to the metal pipe, which are respectively arranged on the base (4); an inverted "U"-shaped frame (5) is arranged on the base (4), and the bottom ends of the two longitudinal walls of the "U"-shaped frame (5) are fixedly connected to the top of the base (4); the testing assembly comprises a driving motor (6), a motor side crank (7), a planetary gear (8), an inner gear ring (9), a gear side crank (10), a connecting rod (11 ), a piston (12), a guide seat (13), a mounting rod (14) and a hammer head (15), the drive motor (6) is fixedly arranged on the top of the transverse wall of the "U"-shaped frame (5), the inner gear ring (9) is fixedly arranged on the top of the transverse wall of the "U"-shaped frame (5) and is located on one side of the output shaft of the drive motor (6), the output shaft of the drive motor (6) is fixedly connected to the motor side crank (7), one end of the motor side crank (7) is rotatably connected to the axis of the planetary gear (8), and the planetary gear (8) is meshingly connected to the inner gear ring (9), One end of the gear side crank (10) is fixedly connected to the axis of the planetary gear (8), and the other end of the gear side crank (10) is rotatably connected to one end of the connecting rod (11). The diameter of the inner gear ring (9) is twice the diameter of the planetary gear (8). The rotation axis of the connecting rod (11) and the gear side crank (10) is located on the pitch circle of the planetary gear (8). The guide seat (13) is vertically fixed to the bottom of the horizontal wall of the "U"-shaped frame (5). One side of the guide seat (13) is provided with a groove along the inner gear ring (9). The first slide groove is arranged on the vertical center line of the "U"-shaped frame (5), the piston (12) is slidably arranged in the first slide groove, the other end of the connecting rod (11) passes through the transverse wall of the "U"-shaped frame (5) and is rotatably connected to the top of the piston (12), the transverse wall of the "U"-shaped frame (5) is provided with a clearance hole that cooperates with the connecting rod (11), the bottom of the piston (12) is fixedly connected to the mounting rod (14), and the bottom of the mounting rod (14) is fixedly connected to the hammer head (15); the clamp assembly is fixedly arranged on the top of the base (4) and is located below the hammer head (15). 2. The metal fatigue resistance testing device according to claim 1 is characterized in that the fixture assembly comprises a mounting seat (16), a fixed block (17), a sliding block (18) and a fixture, the mounting seat (16) is fixedly arranged on the top of the base (4), a second slide groove is opened on the top of the mounting seat (16), the fixed block (17) is fixedly arranged at one end of the second slide groove, the sliding block (18) is slidably arranged at the other end of the second slide groove, and the opposite sides of the fixed block (17) and the sliding block (18) are respectively provided with fixtures. 3. The metal fatigue resistance testing device according to claim 2 is characterized in that a screw rod (19) is provided in the second slide groove, one end of the screw rod (19) is rotatably connected to the lower part of the fixed block (17), the other end of the screw rod (19) is threadedly connected to the lower part of the sliding block (18) and passes through the side wall of the mounting seat (16) and extends to the outside of the mounting seat (16), the other end of the screw rod (19) is rotatably connected to the mounting seat (16), and the part of the other end of the screw rod (19) exposed outside the mounting seat (16) is fixedly connected to a handle (20). 4. The metal fatigue resistance testing device according to claim 2 is characterized in that the clamp comprises a chuck (21), a clamping plate (22) and a clamping column (23), one side of the chuck (21) is rotatably connected to the fixed block (17) and the opposite side of the sliding block (18) through a rotating shaft (24), one end of the rotating shaft (24) on the chuck (21) corresponding to the fixed block (17) passes through the fixed block (17) and is then transmitted to the output shaft of the driving motor (6) through the transmission assembly. The side wall of the chuck (21) is evenly penetrated by a plurality of clamping columns (23) arranged along the radial direction of the chuck (21); the clamping columns (23) are slidably connected to the side wall of the chuck (21); one end of the clamping column (23) located on the inner side of the chuck (21) is fixedly connected to a clamping plate (22); one end of the clamping column (23) located on the outer side of the chuck (21) is fixedly connected to a baffle (25); a spring (26) is connected between the baffle (25) and the side wall of the chuck (21). 5. The metal fatigue resistance testing device according to claim 4 is characterized in that the transmission assembly comprises a worm wheel, a transmission shaft (29), a driving bevel gear (30) and a driven bevel gear (31), a part of the output shaft of the drive motor (6) is a worm, the worm wheel is meshingly connected with the worm, the top end of the transmission shaft (29) is fixedly connected to the axis of the worm wheel, the bottom end of the transmission shaft (29) passes through the lateral wall of the "U"-shaped frame (5) and is rotatably connected to the lateral wall of the "U"-shaped frame (5), the bottom end of the transmission shaft (29) is fixedly connected with the driving bevel gear (30), the driving bevel gear (30) is meshingly connected with the driven bevel gear (31), and one end of the rotating shaft (24) corresponding to the fixed block (17) is fixedly connected to the axis of the driven bevel gear (31). 6. The metal fatigue resistance testing device according to claim 5 is characterized in that the driven bevel gear (31), the rotating shaft (24), the chuck (21) axis center and the corresponding positions of the fixed block (17) and the sliding block (18) are provided with interconnected through cavities, the inner side wall of the cavity is provided with an internal thread, the cavity is threadedly connected with a threaded rod (32), one end of the threaded rod (32) extends into the chuck (21) and is fixedly connected to a conical chuck (33), and the other end of the threaded rod (32) extends out of the cavity and is fixedly connected to a handle (20). 7. The metal fatigue resistance testing device according to claim 1, characterized in that a roller (34) is rotatably connected to the bottom of the hammer head (15). 8. The metal fatigue resistance testing device according to claim 1 is characterized in that a thin film pressure sensor (35) is provided between the hammer head (15) and the mounting rod (14), a display screen (36) is fixedly provided on the base (4), and the thin film pressure sensor (35) and the display screen (36) are connected via a wire signal.