Small rotating bending fatigue testing machine

Abstract

The utility model relates to the field of material fatigue testing devices, in particular to a small-sized rotary bending fatigue testing machine, which comprises a rack assembly, a high-speed main shaft, a loading assembly, a detection assembly and a control system, and is characterized in that a main shaft motor and the high-speed main shaft are arranged on the rack assembly and are in transmission connection through a belt transmission assembly; the output end of the high-speed main shaft is provided with a clamping assembly for clamping a sample, the loading assembly is used for being hung at the other end of the sample, and the control system is used for controlling the main shaft motor to stop rotating when the number of rotation turns of the sample detected by the detection assembly reaches a preset number of rotation turns or the sample is broken. According to the utility model, the structural complexity of the whole device is simplified, so that the device is simple in structure, accurate in loading and stable and reliable in operation.

Description

Technical Field

[0001] The utility model relates to the field of material fatigue testing devices, in particular to a small rotary bending fatigue testing machine. Background Art

[0002] The destruction of materials under cyclic loads is called fatigue failure. The stress at which fatigue failure occurs is generally lower than the yield stress of the material. Fatigue generally begins with microstructural changes caused by internal stress and strain in the material. With the addition of cyclic loads, this change gradually evolves into permanent macroscopic cracks. As cracks in different parts expand, the material eventually fails. Rotational bending fatigue is a form of fatigue in which a high-speed rotating structure is simultaneously subjected to a bending moment, in which the material is subjected to gradient cyclic stress. Rotational bending fatigue test requirements: The specimen rotates and is subjected to a bending moment, and the force that generates the bending moment is constant and does not rotate.

[0003] The implementation of material fatigue testing is inseparable from various types of fatigue testing machines. For rotary bending fatigue testing machines, most of the existing ones in China use cantilever levers to assist weight loading, which requires a corresponding tailstock or guide rail on the table, often making the loading device more complicated and increasing the installation and adjustment steps of the specimen; because loading requires a longer tail rod support, and the overall power-transmission system of the equipment is mostly arranged in a straight line, there are many components along the length of the equipment, which makes the length of the equipment larger and the equipment more bulky.

[0004] Therefore, it is necessary to provide a small rotary bending fatigue testing machine to solve the above problems. Utility Model Content

[0005] The utility model provides a small rotary bending fatigue testing machine to solve the problem that most of the prior art uses cantilever levers to assist weight loading, which requires a corresponding tailstock or guide rail to be matched on the table, often making the loading device more complicated and increasing the installation and adjustment steps of the sample; since loading requires a longer tail rod support and the overall power-transmission system of the equipment is mostly arranged in a straight manner, the number of components on the length of the equipment is large, making the length of the equipment larger and the equipment more bulky.

[0006] The utility model adopts a small rotary bending fatigue testing machine adopts the following technical scheme, including:

[0007] The frame assembly has a spindle motor horizontally slidably arranged in the middle, and a high-speed spindle is horizontally rotatably arranged on the top; the input end of the high-speed spindle is connected to the output end of the spindle motor through a belt transmission assembly, and the output end of the high-speed spindle is provided with a clamping assembly for clamping one end of the sample;

[0008] A loading assembly, which is used to be suspended at the other end of the sample, and comprises: a U-shaped force-adding seat, a suspension assembly for hanging the rudder-adding weight is arranged at the bottom of the U-shaped force-adding seat, a bearing seat is rotatably arranged in the U-shaped groove on the upper side, a connecting ring is rotatably connected in the bearing seat through the bearing, and the other end of the sample is used to be connected to the ring hole of the connecting ring;

[0009] A detection component and a control system, wherein the control system is used to control the spindle motor to stop rotating when the number of rotations of the sample detected by the detection component reaches a preset number of rotations or the sample breaks.

[0010] Preferably, the clamping assembly comprises: an ER nut, which is arranged at the output end of the high-speed spindle, and an ER collet is connected inside the ER nut.

[0011] Preferably, the suspension assembly comprises: a lifting ring connected to the bottom of the U-shaped force-adding seat, and the lifting ring is connected to a lifting hook weight seat for placing the rudder-adding weight via a spring.

[0012] Preferably, it also includes a tensioning assembly, which is arranged on one side of the spindle motor and is used to adjust the position of the spindle motor to adjust the tightness of the conveyor belt of the belt transmission assembly.

[0013] Preferably, the tensioning assembly includes: a fixed mounting plate horizontally mounted on the frame assembly, a movable mounting plate slidably arranged on the fixed mounting plate, a top screw bolt is arranged on the fixed mounting plate through a top screw seat, and the end of the top screw bolt is in contact with the side end surface of the movable mounting plate; a limit guide assembly for limiting the movement of the movable mounting plate is also arranged on the movable mounting plate; wherein the spindle motor is arranged on the movable mounting plate.

[0014] Preferably, the position limiting guide assembly comprises: a locking bolt and a long through slot provided on the movable mounting plate, and the locking bolt passes through the long through slot to fasten the movable mounting plate to the fixed mounting plate.

[0015] Preferably, a cylindrical pin is arranged between the side wall of the bearing seat and the inner wall of the U-shaped groove of the U-shaped force seat, one end of the cylindrical pin is fixed to the side wall of the bearing seat, and the other end of the cylindrical pin is rotatably connected to the inner wall of the U-shaped groove of the U-shaped force seat.

[0016] Preferably, the detection component includes: a spindle magnet, which is arranged on the high-speed spindle, and a counting sensor is arranged at the same height position of the frame assembly on one side of the high-speed spindle, and the number of times the spindle magnet is detected by the counting sensor is used as the number of rotations of the sample; a force seat magnet is arranged on the top of the U-shaped force seat, and a normally closed Hall sensor is arranged on the frame assembly above the U-shaped force seat, and the sample is broken when the force seat magnet cannot be detected within the detection range of the normally closed Hall sensor.

[0017] Preferably, the control system includes: a control box, in which a frequency converter, a counter and a controller are arranged; the normally closed switch of the counter and the normally closed Hall sensor are both connected in series in the control loop of the spindle motor; the counter is used to receive the number of rotations of the sample detected by the counting sensor, and the counter sends the received number of rotations of the sample to the controller, when the controller determines that the received number of rotations of the sample meets the preset number of rotations, the controller controls the normally closed switch of the counter to disconnect, or when the controller receives that the normally closed Hall sensor does not detect the force seat magnet, the controller controls the normally closed switch of the normally closed Hall sensor to automatically disconnect to control the spindle motor to stop; the frequency converter is used to adjust the speed of the spindle motor; wherein the counting sensor, the normally closed Hall sensor and the spindle motor are all electrically connected to the controller.

[0018] Preferably, the belt drive assembly includes a driving pulley, a conveyor belt and a driven pulley, the driving pulley is fixed to the output end of the spindle motor, the driven pulley is fixed to the input end of the high-speed spindle, and the conveyor belt is connected between the driving pulley and the driven pulley.

[0019] The beneficial effects of the utility model are:

[0020] 1. The bearing seat is set by rotating on the U-shaped force-adding seat of the loading component, and then a connecting ring is connected to the bearing seat through the bearing rotation. The connecting ring is used to hang on the free end of the sample, so that when the loading component is hung on the sample, the bearing seat can rotate, thereby ensuring its own rotational freedom, so that the rudder weight connected to the lower part of the loading component is less affected, ensuring the stability of loading, and thus ensuring the accuracy of the loading test. The overall configuration of the double-layer staggered design is that the high-speed spindle is set on the upper layer of the frame component, and the spindle motor is installed on the middle layer of the frame component. At the same time, the belt drive component is used to transmit the power output by the spindle motor to the high-speed spindle, thereby simplifying the design of the transmission part, that is, reducing the number of components on the length of the equipment, reducing the length size of the equipment, making it compact in structure, highly integrated as a whole, and occupying a small area; through the design of the freely suspended loading component, other accessories on the top surface of the frame component are reduced. Secondly, the loading component is freely suspended at the end of the sample without other constraints, so the loading weight of the loading component acts entirely on the sample, that is, the structural complexity of the entire device is simplified, while making the device structure simple, the loading is accurate, and the operation is stable and reliable.

[0021] 2. Secondly, the utility model can carry out rotary bending fatigue strength test and fatigue interruption test at room temperature on small-sized standard specimens, and the test process complies with national standards; the whole machine has a simple and compact structure, a highly integrated design, and a small footprint; the whole machine has stepless frequency conversion speed regulation, which enables the specimen to run at different speeds (maximum 6000r / min) with high operating efficiency; specimens of different sizes that meet national standards can be installed by replacing the clamping device, and the operation is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of the overall structure of a small rotary bending fatigue testing machine of the utility model;

[0024] Figure 2 For the utility model Figure 1 A schematic diagram of the structure of the rack assembly in FIG.

[0025] Figure 3 It is a structural schematic diagram of a spindle motor, a belt drive assembly and a high-speed spindle in a small rotary bending fatigue testing machine of the utility model;

[0026] Figure 4 It is a structural schematic diagram of a tensioning assembly in a small rotary bending fatigue testing machine of the utility model;

[0027] Figure 5 It is a structural schematic diagram of a loading component in a small rotary bending fatigue testing machine of the utility model;

[0028] Figure 6 For the utility model Figure 5 A partial enlarged view of the middle A;

[0029] Figure 7 It is a schematic diagram of the position relationship between the spindle magnet and the counting sensor on the high-speed spindle of a small rotary bending fatigue testing machine of the utility model;

[0030] Figure 8 A structural schematic diagram of a control system in a small rotary bending fatigue testing machine of the utility model;

[0031] Fig. 9 A schematic diagram of the positional relationship between a normally closed Hall sensor and a force-adding seat magnet after a loading assembly is suspended on a specimen in a small rotary bending fatigue testing machine of the utility model;

[0032] Fig.10 The utility model is a schematic diagram of the structure of a small rotary bending fatigue testing machine after a conveyor belt protective cover is removed.

[0033] In the figure: 1. rack; 101. frame; 102. cover plate; 103. door plate; 104. hinge; 105. handle; 106. table bottom plate; 107. foot; 108. conveyor belt protection cover; 109. specimen protection cover; 2. spindle motor; 3. belt drive assembly; 301. driving pulley; 302. conveyor belt; 303. driven pulley; 304. high-speed spindle; 305. support; 306. ER nut; 307. ER collet; 308. specimen; 4. tensioning assembly; 401. movable mounting plate; 402. fixed mounting plate; 403. lock Tightening bolt; 404, top screw bolt; 405, top screw seat; 5, loading assembly; 501, U-shaped force seat; 502, cylindrical pin; 503, bearing seat; 504, connecting ring; 505, high-speed bearing; 506, lifting ring; 507, spring; 508, hook weight seat; 509, rudder weight; 510, fixed top screw; 6, control assembly; 601, control box; 602, frequency converter; 603, counter; 604, switch assembly; 605, counting sensor; 606, spindle magnet; 607, normally closed Hall sensor; 608, force seat magnet. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0035] An embodiment of a small rotary bending fatigue testing machine of the utility model is as follows Figure 1 and Fig.10 As shown, it includes: a frame assembly 1, a high-speed spindle 304, a loading assembly 5, a detection assembly and a control system 6; the frame assembly 1, wherein the lower part thereof is provided with a spindle motor 2 for horizontal sliding, and the upper part thereof is provided with a high-speed spindle 304 for horizontal rotation; the input end of the high-speed spindle 304 is connected to the output end of the spindle motor 2 through a belt transmission assembly 3, and the output end of the high-speed spindle 304 is provided with a clamping assembly for clamping one end of the sample 308; the loading assembly 5 is used to be suspended at the other end of the sample 308, and the loading assembly 5 includes: a U-shaped loading assembly A force seat 501, a suspension component for suspending a rudder weight 509 is arranged at the bottom of the U-shaped force seat 501, a bearing seat 503 is rotatably arranged in the U-shaped groove thereon, a connecting ring 504 is rotatably connected to the bearing seat 503 through a bearing 505, and the other end of the sample 308 is used to be connected to the ring hole of the connecting ring 504; a detection component and a control system 6, the control system 6 is used to control the spindle motor 2 to stop when the number of rotations of the sample 308 detected by the detection component reaches a preset number of rotations or the sample 308 is broken.

[0036] Among them, Figure 5 As shown, the suspension assembly includes: a lifting ring 506 connected to the bottom of the U-shaped booster seat 501, the lifting ring 506 is connected to a hook weight seat 508 for placing a rudder weight 509 through a spring 507, a cylindrical pin 502 is arranged between the side wall of the bearing seat 503 and the inner wall of the U-shaped groove of the U-shaped booster seat 501, one end of the cylindrical pin 502 is fixed to the side wall of the bearing seat 503, and the other end of the cylindrical pin 502 is rotatably connected to the inner wall of the U-shaped groove of the U-shaped booster seat 501; in this embodiment, when the suspension assembly is suspended on the sample 308, specifically, the free end of the sample 308 is extended into the inner hole of the connecting ring 504, and is pressed by the fixed top screw 510 on the connecting ring 504, so that the sample 308 drives the connecting ring 504 to rotate. The outside of the connecting ring 504 is a high-speed bearing 505 and a bearing seat 503. The centers of the two sides of the bearing seat 503 are connected by threads with cylindrical pins 502. The cylindrical pins 502 are rotatably connected to the force-adding seat 501, so that the bearing seat 503 can rotate around the cylindrical pins 502, while the force-adding seat 501 remains vertical to ensure the stability of loading. The bottom of the force-adding seat 501 is connected to a lifting ring 506 by threads. The lifting ring 506 is connected to a hook weight seat 508 on which a rudder-adding weight 509 is placed through a spring 507. The rudder-adding weight 509 is placed on the hook weight seat 508. The spring 507 is used to reduce the vibration of the rudder-adding weight 509 during the experiment caused by processing and installation errors.

[0037] Specifically, Figure 3 As shown, the clamping assembly of this embodiment includes: an ER nut 306, which is arranged at the output end of the high-speed spindle 304. Specifically, a conical chuck seat with external threads is arranged at the output end of the high-speed spindle 304, and the ER nut 306 is connected to the high-speed spindle 304 through the conical chuck seat with external threads. An ER collet 307 is connected inside the ER nut 306, and the ER collet 307 is used to clamp the sample 308.

[0038] like Figure 2As shown, the rack assembly 1 of this embodiment includes: a frame 101, a cover plate 102, a door panel 103, a hinge 104, a handle 105, a table bottom plate 106, a foot 107, a conveyor belt protection cover 108 and a sample protection cover 109. The frame 101 forms an outer frame and an inner frame inside the outer frame. The outer frame and the inner frame are connected as a whole by matching bolts and nuts. The top of the outer frame forms the upper layer of the rack assembly 1, and the top of the inner frame forms the middle layer of the rack assembly 1. In this embodiment, aluminum profiles are selected as the material of the frame 101, and the frame 101 is connected by multiple aluminum plates with corner pieces. The cover plate 102 is fixed to the frame 101 by bolts and nuts, the door panel 103 is connected to the frame 101 by hinges 104, and the handle 105 is installed in the middle of the door panel. The door panel 103 is a double-door form, which can be rotated around the hinge 104 to open, so as to facilitate the addition and subtraction of weights in subsequent tests. The table bottom plate 106 is installed on the top of the outer frame, and holes are opened on it for the conveyor belt of the belt drive assembly 3 and the ring 506 and spring 507 of the loading assembly 5 to pass through. The foot 107 is installed on the bottom of the frame 101 through threads. There are nuts on the foot 107 to adjust the frame 101 as a whole to make it level. The bottom of the foot 107 can be fixed to the ground by bolts. Figure 1 and Figure 2 As shown, the conveyor belt protection cover 108 is arranged outside the transmission assembly 3, and the conveyor belt protection cover 108 is fixed to the conveyor belt opening of the table bottom plate 106 by bolts, and the conveyor belt protection cover 108 is made of sheet metal. The sample protection cover 109 is a transparent structure, which can be detachably connected to the table bottom plate 106. The sample protection cover 109 is freely placed on the table bottom plate 106 and covers the loading assembly 5 to cover the loading part, so as to observe the operation of the test machine and prevent the sample 308 and the parts of the loading assembly 5 from falling out during operation. The sample protection cover 109 is made of acrylic plate; it should be noted that, Figure 1 and 3 As shown, the high-speed spindle 304 is a stepped shaft. The high-speed spindle 304 is horizontally mounted on the top of the table bottom plate 106 on the top of the frame 101 through two supports 305, and is supported by the left and right supports 305. The supports 305 are fixed to the table bottom plate by bolts and nuts, and a pair of angular contact ball bearings arranged back to back are arranged inside, so that it has greater bending stiffness and ensures rotation accuracy and bearing capacity.

[0039] like Figure 3As shown, in the embodiment of the utility model, the belt transmission assembly 3 includes a driving pulley 301, a conveyor belt 302, and a driven pulley 303; the driving pulley 301 is fixed to the output shaft of the spindle motor 2 through a flat key and a top screw, and the driven pulley 303 is installed at the input end of the high-speed spindle 304 through a flat key and a top screw, and is fixed with a shaft end retaining ring and a bolt, and the bolt is equipped with a spring washer to prevent loosening; the conveyor belt 302 is sleeved on the driving pulley 301 and the driven pulley 303. In this embodiment, the conveyor belt 302 can be a synchronous belt to improve the transmission accuracy.

[0040] like Figure 4 As shown, in the embodiment of the utility model, a tensioning assembly 4 is also included. The tensioning assembly 4 is arranged on one side of the spindle motor 2 and is used to adjust the position of the spindle motor 2 to adjust the tightness of the conveyor belt 302 of the belt transmission assembly 3; Figure 4 As shown, in the embodiment of the utility model, the tensioning assembly 4 includes: a fixed mounting plate 402 horizontally mounted on the frame assembly 1, a movable mounting plate 401 is slidably arranged on the fixed mounting plate 402, a top screw bolt 404 is arranged on the fixed mounting plate 402 through a top screw seat 405, and the end of the top screw bolt 404 contacts the side end surface of the movable mounting plate 401; a limit guide assembly for limiting the movement of the movable mounting plate 401 is also arranged on the movable mounting plate 401; specifically, the limit guide assembly includes: a locking bolt 403 and a long through slot opened on the movable mounting plate 401, and the locking bolt 403 passes through the long through slot to fasten the movable mounting plate 401 to the fixed mounting plate 402. Among them, the spindle motor 2 is arranged on the movable mounting plate 401. It should be noted that, in this embodiment, the movable mounting plate 401 and the fixed mounting plate 402 are pressed together by the locking bolts 403. At the same time, the limiting guide assembly can also be provided with matching straight protrusions and grooves on the movable mounting plate 401 and the fixed mounting plate 402. The protrusions and grooves cooperate to enable the movable mounting plate 401 to slide straightly along the fixed mounting plate 402. The spindle motor 2 is fixed to the movable mounting plate 401 by bolts; the top screw seat 405 is installed on the fixed mounting plate 402 by bolts, and the top screw bolts 404 pass through the top screw seat 405 to tighten the side wings of the movable mounting plate 401. When the tightness of the conveyor belt 302 needs to be adjusted, the locking bolt 403 is loosened, and the movable mounting plate 401 is pushed outward by tightening the top screw bolt 404 to move the spindle motor 2, so that the driving pulley 301 is away from the driven pulley 303, thereby achieving the tensioning of the conveyor belt 302; by loosening the top screw bolt 404, and then manually pushing the movable mounting plate 401 to move the spindle motor 2, the driving pulley 301 is moved close to the driven pulley 303, thereby achieving the loosening of the conveyor belt 302; after the adjustment is completed, the locking bolt 403 is tightened to fix the movable mounting plate 401 to fix the spindle motor 2.

[0041] Specifically, Figure 7 and Fig. 9 As shown, the detection component includes: a spindle magnet 606, which is arranged on the high-speed spindle 304, and a counting sensor 605 is arranged at the same height position of the frame assembly 1 on one side of the high-speed spindle 304. The number of times the spindle magnet 606 is detected by the counting sensor 605 is used as the number of rotations of the sample 308; a force seat magnet 608 is arranged on the top of the U-shaped force seat 501, and a normally closed Hall sensor 607 is arranged on the frame assembly 1 above the U-shaped force seat 501. When the force seat magnet 608 cannot be detected within the detection range of the normally closed Hall sensor 607, the sample 308 is broken.

[0042] Specifically, Figure 8As shown, the control system 6 includes: a control box 601, in which a frequency converter 602, a counter 603 and a controller are arranged; the normally closed switch of the counter 603 and the normally closed Hall sensor 607 are connected in series in the control loop of the spindle motor 2; the counting sensor 605, the normally closed Hall sensor 607 and the spindle motor 2 are all electrically connected to the controller, the counter 603 is used to receive the number of rotations of the sample 308 detected by the counting sensor 605, and the counter 603 sends the received number of rotations of the sample 308 to the controller, and the controller determines that the received number of rotations of the sample 308 meets the requirements. When the preset number of revolutions is reached, the controller controls the normally closed switch of the counter 603 to be disconnected, or when the controller receives that the normally closed Hall sensor 607 does not detect the force seat magnet 608, the controller controls the normally closed switch of the normally closed Hall sensor 607 to be automatically disconnected to control the spindle motor 2 to stop rotating; the frequency converter 602 is used to adjust the speed of the spindle motor 2; a switch display component 604 is also set on the outer wall of the control box 601, and the switch display component 604 includes a spindle motor switch, a frequency converter speed control switch, a counter adjustment button, a spindle speed display screen and a counting display screen; the frequency converter 602 is a stepless frequency conversion speed control. The counter 603 is a six-digit counter, and the maximum display of the six-digit counter is 999999. The display value can be adjusted by setting the magnification n. The input signal multiplied by the magnification is the final display value, that is, the actual number of revolutions is equal to the display value ÷ n, and the adjustable range of n is 0.0001-9.9999. In addition, the counter standard mode is to stop when the preset number is reached; the counting sensor 605 is a Hall sensor, which is fixed on the table bottom plate 106 through a bracket. The counting sensor 605 is set at the same height position of the frame assembly 1 on one side of the high-speed spindle 304. The spindle magnet 606 is pasted on the position of the high-speed spindle 304 directly opposite the counting sensor 605. Every time the high-speed spindle 304 rotates one circle, the spindle magnet 606 is detected once by the counting sensor 605, and the counting sensor 605 transmits a signal to the counter. The normally closed Hall sensor 607 is a normally closed Hall sensor, which is fixed on the table bottom plate above the loading system with a bracket and connected in series to the control circuit of the spindle motor. When there is a magnet in the sensing range of the sensor, it is in a closed state. Conversely, it is in a disconnected state when there is no magnet in the detection range. A force seat magnet 608 is pasted on the position above the force seat 501 directly opposite the normally closed Hall sensor 607. When the sample 308 is loaded normally, the force seat magnet 608 is within the sensing range of the normally closed Hall sensor 607, and the normally closed Hall sensor 607 is in a closed state; when the sample 308 breaks, the force seat 501 descends, and the controller controls the normally closed switch of the normally closed Hall sensor 607 to disconnect, thereby controlling the spindle motor 2 to stop.

[0043] Specific test principle

[0044] When in use, in the embodiment of the utility model, when conducting a test, set the display magnification of the counter and clear it to zero, set the preset number of test turns (if the sample 308 needs to be stopped when it breaks, set a larger value); clamp the clamping end of the sample 308 into the ER collet 307 of the clamping assembly at one end of the high-speed spindle 304, then tighten the ER nut 306 to clamp the sample 308, and then extend the other end of the sample 308 into the ring hole of the connecting ring 504 of the suspension assembly, and fix the test by tightening the top screw on the connecting ring 504. Sample 308, hang a hook weight seat 508 with a hook on the spring 507, start the spindle motor 2 and gradually accelerate to the speed required for the test, and after stable operation, add rudder weights 509 to the hook weight seat 508 step by step to the required loading weight; it should be noted that the loading weight here needs to remove the redundant weight introduced by the loading assembly 5, that is, the total weight of the U-shaped force seat 501, the cylindrical pin 502, the bearing seat 503, the connecting ring 504, the high-speed bearing 505, the hanging ring 506 and the spring 507. When the sample 308 breaks or the running reaches the specified number of circles, the spindle motor 2 automatically stops. The relationship between the load, torque and stress of the testing machine of the embodiment of the utility model is affected differently by the shape of the sample. When a funnel-shaped sample is used, the relationship between the stress on the surface of the sample 308 and the load and torque is:

[0045]

[0046]

[0047] M=PL

[0048] Among them, σ is stress, M is moment, I is moment of inertia, D is the diameter of the specimen test position (the thinnest part of the specimen), P is load, and L is the lever arm.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A small rotary bending fatigue testing machine, characterized in that: include: A frame assembly (1), wherein a spindle motor (2) is horizontally slidably arranged in the middle thereof, and a high-speed spindle (304) is horizontally rotatably arranged at the top thereof; the input end of the high-speed spindle (304) is transmission-connected to the output end of the spindle motor (2) via a belt transmission assembly (3), and a clamping assembly for clamping one end of a sample (308) is arranged at the output end of the high-speed spindle (304); A loading assembly (5) is used to be suspended on the other end of the sample (308), and comprises: a U-shaped force-adding seat (501), a suspension assembly for suspending a rudder-adding weight (509) is arranged at the bottom of the U-shaped force-adding seat (501), a bearing seat (503) is rotatably arranged in the U-shaped groove on the upper side, a connecting ring (504) is rotatably connected in the bearing seat (503) via a bearing (505), and the other end of the sample (308) is used to be connected to the ring hole of the connecting ring (504); A detection component and a control system (6), wherein the control system (6) is used to control the spindle motor (2) to stop rotating when the number of rotations of the sample (308) detected by the detection component reaches a preset number of rotations or the sample (308) is broken.

2. A small rotary bending fatigue testing machine according to claim 1, characterized in that: The clamping assembly comprises an ER nut (306), wherein the ER nut (306) is arranged at the output end of the high-speed spindle (304), and an ER collet (307) is connected inside the ER nut (306).

3. A small rotary bending fatigue testing machine according to claim 1, characterized in that: The suspension assembly comprises a lifting ring (506) connected to the bottom of the U-shaped booster seat (501), and the lifting ring (506) is connected to a lifting hook weight seat (508) for placing a rudder booster weight (509) via a spring (507).

4. A small rotary bending fatigue testing machine according to claim 1, characterized in that: It also includes a tensioning assembly (4), which is arranged on one side of the spindle motor (2) and is used to adjust the position of the spindle motor (2) so as to adjust the tightness of the conveyor belt (302) of the belt transmission assembly (3).

5. A small rotary bending fatigue testing machine according to claim 4, characterized in that: The tensioning assembly (4) comprises: a fixed mounting plate (402) horizontally mounted on the frame assembly (1); a movable mounting plate (401) slidably mounted on the fixed mounting plate (402); a top screw bolt (404) is mounted on the fixed mounting plate (402) via a top screw seat (405); the end of the top screw bolt (404) contacts the side end surface of the movable mounting plate (401); and a limit guide assembly for limiting the movement of the movable mounting plate (401) is also mounted on the movable mounting plate (401); wherein the spindle motor (2) is mounted on the movable mounting plate (401).

6. A small rotary bending fatigue testing machine according to claim 5, characterized in that: The limiting guide assembly comprises: a locking bolt (403) and a long through slot provided on the movable mounting plate (401); the locking bolt (403) passes through the long through slot to fasten the movable mounting plate (401) to the fixed mounting plate (402).

7. The small rotary bending fatigue testing machine according to claim 1, characterized in that: A cylindrical pin (502) is provided between the side wall of the bearing seat (503) and the inner wall of the U-shaped groove of the U-shaped energizing seat (501); one end of the cylindrical pin (502) is fixed to the side wall of the bearing seat (503), and the other end of the cylindrical pin (502) is rotatably connected to the inner wall of the U-shaped groove of the U-shaped energizing seat (501).

8. The small rotary bending fatigue testing machine according to claim 1, characterized in that: The detection component comprises: a spindle magnet (606) arranged on a high-speed spindle (304); a counting sensor (605) is arranged at an equal height position of a frame component (1) on one side of the high-speed spindle (304); the number of times the spindle magnet (606) is detected by the counting sensor (605) is used as the number of rotations of the sample (308); a force seat magnet (608) is arranged on the top of the U-shaped force seat (501); a normally closed Hall sensor (607) is arranged on the frame component (1) above the U-shaped force seat (501); when the force seat magnet (608) cannot be detected within the detection range of the normally closed Hall sensor (607), the sample (308) is broken.

9. A small rotary bending fatigue testing machine according to claim 8, characterized in that: The control system (6) comprises: a control box (601) in which a frequency converter (602), a counter (603) and a controller are arranged; The normally closed switch of the counter (603) and the normally closed Hall sensor (607) are both connected in series in the control circuit of the spindle motor (2); The counter (603) is used to receive the number of rotations of the sample (308) detected by the counting sensor (605), and the counter (603) sends the received number of rotations of the sample (308) to the controller. When the controller determines that the received number of rotations of the sample (308) meets a preset number of rotations, the controller controls the normally closed switch of the counter (603) to be disconnected, or when the controller receives that the normally closed Hall sensor (607) does not detect the force seat magnet (608), the controller controls the normally closed switch of the normally closed Hall sensor (607) to be automatically disconnected, so as to control the spindle motor (2) to stop rotating; A frequency converter (602) for adjusting the speed of the spindle motor (2); The counting sensor (605), the normally closed Hall sensor (607) and the spindle motor (2) are all electrically connected to the controller.

10. The small rotary bending fatigue testing machine according to claim 1, characterized in that: The belt transmission assembly (3) comprises a driving pulley (301), a conveyor belt (302) and a driven pulley (303); the driving pulley (301) is fixedly mounted on the output end of the spindle motor (2); the driven pulley (303) is fixedly mounted on the input end of the high-speed spindle (304); and the conveyor belt (302) is drivingly connected between the driving pulley (301) and the driven pulley (303).

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