Cantilever type flat plate reciprocating bending fatigue testing machine

Abstract

The utility model relates to a cantilever type flat plate reciprocating bending fatigue testing machine which comprises a rack, a heating system is arranged on a top plate of the rack, and a fixing assembly used for fixing the fixed end of a horizontally arranged flat plate sample is arranged in the heating system. The right side of the fixing assembly is provided with a loading assembly used for being connected with the free end of the flat plate sample; a power assembly is arranged on a bottom plate of the machine frame, the power output end of the power assembly is connected with a loading assembly through a conjugate transmission assembly capable of vertically moving in a reciprocating mode, the power assembly drives the loading assembly to swing up and down through the conjugate transmission assembly, and reciprocating bending of a flat plate sample is achieved. The device is reasonable in design, can realize reciprocating bending fatigue test of a flat sample in a high-temperature environment, is beneficial to material fatigue life research in the high-temperature environment, and is high in reliability, accurate in loading and low in cost.

Description

Technical field:

[0001] The utility model relates to a cantilever type flat plate reciprocating bending fatigue testing machine. Background technology:

[0002] Fatigue damage of parts will affect production efficiency and thus the economy, and more seriously, it will endanger the lives of workers. In order to prevent fatigue damage, it is necessary to explore the fatigue life of materials. The current method is to conduct fatigue tests, and the equipment used for fatigue tests is fatigue testing machines.

[0003] At present, the most common fatigue testing machine is the bending fatigue testing machine, which is often used for fatigue testing of rod-shaped specimens. There are fewer fatigue testing machines suitable for bending fatigue testing of flat specimens. In the prior art, Chinese Patent No. 201110124491.7 discloses a reciprocating bending corrosion fatigue testing machine, which is equipped with multiple eccentric wheel mechanisms on the rotating shaft, and all specimens are immersed in a corrosion tank filled with corrosive media to achieve simultaneous testing of multiple flat specimens in a corrosive environment. Chinese Patent No. 201820391665.3 discloses a metal sheet repeated bending fatigue testing device, the loading mechanism of which adopts a crank-slider mechanism to realize fatigue testing of reciprocating swing bending of the metal sheet in the front and rear directions. This mechanical structure only allows one specimen to be loaded at a time. Chinese Patent No. 201921169211.2 discloses a bending fatigue testing device for flat specimens based on a vibration table, the loading mechanism of which adopts a vibration table, and the test efficiency is greatly improved. However, the above-mentioned flat plate reciprocating bending fatigue testing machines cannot perform fatigue tests in high temperature environments. Therefore, it is necessary to propose a cantilever plate reciprocating bending fatigue testing machine. Utility model content:

[0004] The utility model makes improvements on the problems existing in the above-mentioned prior art, that is, the technical problem to be solved by the utility model is to provide a cantilevered plate reciprocating bending fatigue testing machine.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the utility model is: a cantilevered flat-plate reciprocating bending fatigue testing machine, comprising a frame, a heating system is arranged on the top plate of the frame, a fixing component for fixing the fixed end of a horizontally arranged flat-plate specimen is arranged inside the heating system, and a loading component for connecting with the free end of the flat-plate specimen is arranged on the right side of the fixing component; a power component is arranged on the bottom plate of the frame, and the power output end of the power component is connected to the loading component via a conjugate transmission component that can move back and forth vertically, and the power component drives the loading component to swing up and down through the conjugate transmission component to realize reciprocating bending of the flat-plate specimen.

[0006] Furthermore, the conjugate transmission assembly includes a yoke, an eccentric spline shaft, an inner eccentric wheel, an outer eccentric wheel and a bearing. The yoke is vertically arranged, and a stepped through hole is arranged in the middle part of the yoke and runs through in the transverse direction. The eccentric spline shaft is arranged in the transverse direction and the spline portion extends into the stepped through hole; the inner eccentric wheel is provided with a spline hole matching with the spline portion of the eccentric spline shaft, and a limiting flange is arranged on the outer peripheral side of the left end of the inner eccentric wheel; the outer eccentric wheel is sleeved on the outer side of the inner eccentric wheel, and the right end face of the outer eccentric wheel is connected to the middle part of the right end face of the spline portion of the eccentric spline shaft through a connecting gasket; the bearing is sleeved on the outer side of the left end of the outer eccentric wheel, and the bearing is located between the limiting flange and the step surface of the stepped through hole and slides with the left end of the stepped through hole.

[0007] Furthermore, a first connecting hole is opened on the right end face of the outer eccentric wheel near the edge, and a second connecting hole is opened in the middle of the right end face of the spline part of the eccentric spline shaft, and both ends of the connecting gasket are respectively fixed by locking bolts matching the first connecting hole and the second connecting hole.

[0008] Furthermore, a vertically arranged upper shaft is screwed in the middle of the top surface of the yoke, and the upper end of the upper shaft is connected to the loading assembly through a rod end joint bearing; a vertically arranged lower shaft is screwed in the middle of the bottom surface of the yoke, and the lower shaft is slidably matched with a round flange linear bearing arranged at the right end of the bottom plate of the frame.

[0009] Furthermore, the loading assembly includes a pair of Z-shaped rocker arms which are horizontally arranged and symmetrically distributed in the front and rear directions. The right ends of the pair of rocker arms are connected by a joint, and the right end of the joint is hinged to the upper end of the rod end joint bearing; the left ends of the pair of rocker arms are respectively hinged to the hinge seats fixed on the top plate through longitudinal hinge axes, and a longitudinally arranged loading plate is fixed between the bottom ends of the left ends of the pair of rocker arms, and the free end of the flat specimen is locked to the top surface of the loading plate.

[0010] Furthermore, the fixing assembly includes an adjustment frame fixed to the top surface of the top plate, a longitudinally arranged support plate is fixed to the top of the adjustment frame, and the fixed end of the flat sample is locked to the top surface of the support plate.

[0011] Furthermore, the bottom of the left ends of a pair of rocker arms are each provided with a plurality of first locking holes that are evenly spaced laterally and used to cooperate with the first bolt to lock the loading plate; the left end of the top plate is provided with a plurality of second locking holes that are evenly spaced laterally and used to cooperate with the second bolt to lock the adjusting frame.

[0012] Furthermore, the power assembly includes a power motor, the output shaft of the power motor is connected to the input shaft of the power head via a coupling, and the output shaft of the power head is an eccentric spline shaft; a motor seat is fixed to the left end of the base plate, and the power motor is installed on the top of the motor seat.

[0013] Furthermore, it also includes a detection device, which includes a proximity switch, an electronic counter and an automatic control relay. The proximity switch is installed at the right end of the top surface of the motor base and is located directly below the protruding bolt position of the coupling. The proximity switch outputs a high-voltage signal to the electronic counter after detecting that the coupling rotates one circle; the common signal line and the low-level signal line of the automatic control relay are installed in parallel on the support plate, and the high-level signal line of the automatic control relay is installed on the loading plate. When the automatic control relay detects that the common parallel line is disconnected from the high-level line, the counting channel of the proximity switch is cut off.

[0014] Furthermore, the heating system includes a heating furnace covered on the outside of the fixed component and the heating component, the bottom of the heating furnace is supported by a bracket fixed on the top plate, the bottom of the heating furnace is provided with a clearance hole for the upper end of the conjugate transmission component to pass through, the heating furnace is provided with an internal circulation cooling component, and the heating furnace is connected to the temperature control box.

[0015] Compared with the prior art, the utility model has the following effects: the utility model has a reasonable design, can realize the reciprocating bending fatigue test of flat specimens in a high temperature environment, is helpful for the study of material fatigue life in a high temperature environment, and has high reliability, precise loading and low cost. Description of the drawings:

[0016] Figure 1 It is a three-dimensional structural schematic diagram of an embodiment of the utility model;

[0017] Figure 2 It is a schematic diagram of the main structure of an embodiment of the utility model;

[0018] Figure 3 yes Figure 2 The schematic diagram of the heating system is omitted;

[0019] Figure 4 It is a schematic diagram of the top view of the structure of an embodiment of the utility model (the heating system is omitted);

[0020] Figure 5 yes Figure 4 AA section diagram in;

[0021] Figure 6 It is a schematic cross-sectional structure diagram of a conjugate transmission assembly in an embodiment of the utility model;

[0022] Figure 7 It is a schematic diagram of the three-dimensional structure of the yoke in the embodiment of the utility model;

[0023] Figure 8 This is a schematic diagram of eccentricity adjustment in the embodiment of the utility model. Figure 1 ;

[0024] Fig. 9This is a schematic diagram of eccentricity adjustment in the embodiment of the utility model. Figure 2 ;

[0025] Fig.10 It is a working principle diagram of an embodiment of the utility model;

[0026] Fig.11 It is a schematic diagram of the structure of a flat plate sample in an embodiment of the utility model;

[0027] Fig.12 This is a schematic diagram of a repeated bending fatigue test of a flat plate specimen in an embodiment of the utility model;

[0028] Fig.13 It is the result of finite element numerical simulation of stress distribution when the amplitude of the flat plate specimen in the embodiment of the utility model is the largest.

[0029] In the figure:

[0030] 1-Horizontal adjustment support caster; 2-bottom plate; 3-motor seat; 4-power motor; 5-proximity switch; 6-coupling; 7-top plate; 8-heating furnace; 81-bracket, 9-power head; 91-eccentric spline shaft; 10-conjugate transmission assembly; 101-inner eccentric wheel; 1011-limiting flange; 102-outer eccentric wheel; 103-bearing; 104-upper shaft; 105-yoke block; 106-connecting gasket; 107-lower shaft; 11-adjustment frame; 12-support plate; 1 30-first high temperature resistant nylon pad; 131-second high temperature resistant nylon pad; 132-third high temperature resistant nylon gasket; 133-high temperature resistant nylon sleeve; 14-hinge seat; 15-loading plate; 16-rocker; 17-joint; 18-rod end joint bearing, 19-flat specimen; 20-step through hole; 21-first connecting hole; 22-second connecting hole; 23-first locking hole; 24-second locking hole; 25-frame; 26-vertical support rod; 27-round flange linear bearing. Specific implementation method:

[0031] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0032] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0033] like Figures 1 to 9As shown, the utility model is a cantilevered flat plate reciprocating bending fatigue testing machine, comprising a frame 25, a heating system is arranged on the top plate 7 of the frame 25, a fixing assembly for fixing the fixed end of the horizontally arranged flat plate specimen is arranged inside the heating system, and a loading assembly for connecting with the free end of the flat plate specimen 19 is arranged on the right side of the fixing assembly; a power assembly is arranged on the bottom plate 2 of the frame 25, and the power output end of the power assembly is connected to the loading assembly via a conjugate transmission assembly 10 that can reciprocate vertically, and the power assembly drives the loading assembly to swing up and down through the conjugate transmission assembly to achieve reciprocating bending of the flat plate specimen 19. The flat plate specimens arranged on the fixing assembly and the loading assembly are heated by the heating system, and the loading assembly swings up and down driven by the conjugate transmission assembly, and the loading assembly drives the flat plate specimen to bend reciprocatingly up and down, thereby achieving reciprocating bending fatigue test of the flat plate specimen in a high temperature environment, which is helpful for studying the fatigue life of materials in a high temperature environment.

[0034] In this embodiment, the frame 25 includes a top plate 7 and a bottom plate 2 that are distributed in parallel. The top plate 7 and the bottom plate 2 are connected around each other via vertical support rods. Horizontally adjustable support casters 1 are provided around the bottom of the bottom plate 2 for horizontal adjustment and movement of the entire testing machine.

[0035] In this embodiment, the conjugate transmission assembly 10 includes a yoke 105, an eccentric spline shaft 91, an inner eccentric wheel 101, an outer eccentric wheel 102 and a bearing 103. The yoke 105 is vertically arranged, and a stepped through hole 20 is arranged in the middle of the yoke 105 and runs through in the transverse direction. The left end of the stepped through hole 20 has a large aperture and the right end has a small aperture; the eccentric spline shaft 91 is arranged in the transverse direction, and the spline portion of the eccentric spline shaft 91 extends into the stepped through hole 20; the inner eccentric wheel 101 extends into the stepped through hole, and a spline hole matching the spline portion of the eccentric spline shaft is arranged on the inner eccentric wheel 101. The left end of the inner eccentric wheel 101 A limiting flange 1011 is provided on the outer circumference; the outer eccentric wheel 102 extends into the stepped through hole 20, and the outer eccentric wheel 102 is sleeved on the outer side of the inner eccentric wheel 101. The right end face of the outer eccentric wheel 102 is connected to the middle part of the right end face of the spline part of the eccentric spline shaft 91 through a connecting gasket 106, so that the eccentric spline shaft, the inner eccentric wheel and the outer eccentric wheel are connected as a whole, and the three rotate together; the bearing 103 is sleeved on the outer side of the left end of the outer eccentric wheel 102, and the bearing 103 is located between the limiting flange 1011 and the stepped surface of the stepped through hole 20, and the bearing 103 is slidably matched with the left end of the stepped through hole 20. As the eccentric spline shaft 91 rotates, the bearing 103 sleeved on the outer eccentric wheel 102 will slide in the left end of the stepped through hole in the yoke 105, so that the yoke 105 moves up and down, thereby realizing up and down reciprocating linear movement. Preferably, the bearing is a deep groove ball bearing. An eccentric spline shaft and inner and outer eccentric wheel structures are used to achieve reciprocating bending motions with different amplitudes.

[0036] It should be noted that the eccentric spline shaft has an eccentrically arranged spline portion, while the inner eccentric wheel is eccentrically arranged relative to the spline portion, and the outer eccentric wheel is eccentrically arranged relative to the inner eccentric wheel.

[0037] In this embodiment, the right end surface of the outer eccentric wheel 102 is provided with a first connection hole 21 near the edge, the middle part of the right end surface of the spline portion of the eccentric spline shaft 91 is provided with a second connection hole 22, and both ends of the connection gasket 106 are respectively fixed by locking bolts matched with the first connection hole 21 and the second connection hole 22. It should be noted that when the positional relationship between the inner and outer eccentric wheels and the eccentric spline shaft is adjusted according to the amplitude required for the test, the connection gaskets with different spacings between the first connection hole and the second connection hole need to be replaced to adapt.

[0038] In this embodiment, the shape of the flat plate sample 19 is a variable cross-section type in order to meet the requirement of constant stress, and the flat plate sample 19 is loaded in a cantilever manner.

[0039] In this embodiment, the loading assembly includes a pair of Z-shaped rocker arms 16 which are horizontally arranged and symmetrically distributed along the front and rear directions. The left ends of the pair of rocker arms are spaced apart from each other at a large distance, while the right ends of the pair of rocker arms are spaced apart from each other at a small distance. The right ends of the pair of rocker arms 16 are connected by a joint 17, and the joint 17 can be hinged to the right ends of the pair of rocker arms. The right end of the joint 17 is hinged to the upper end of the rod end joint bearing 18. The left ends of the pair of rocker arms 16 are respectively hinged to the hinge seats 14 fixed on the top plate 7 through longitudinal hinge shafts to facilitate the up and down swinging of the pair of rocker arms. A longitudinally arranged loading plate 15 is fixed between the bottom ends of the left ends of the pair of rocker arms 16, and the free end of the flat specimen 19 is bolted to the top surface of the loading plate 15.

[0040] In this embodiment, the fixing assembly includes an adjustment frame 11 vertically fixed to the top surface of the top plate 7, a longitudinally arranged support plate 12 is fixed to the top of the adjustment frame 11, and the fixed end of the flat sample 19 is locked to the top surface of the support plate 12 by bolts.

[0041] In this embodiment, the bottom of the left end of the pair of swing rods 16 is provided with a plurality of first locking holes 23 evenly spaced in the transverse direction, and the first locking holes 23 are used to cooperate with the first bolt to lock the loading plate 15; the left end of the top plate 7 is provided with a plurality of groups of second locking holes 24 evenly spaced in the transverse direction, and the second locking holes 24 are used to cooperate with the second bolt to lock the adjustment frame 11. Through the plurality of first locking holes and the plurality of second locking holes, the fixing positions of the loading plate and the adjustment frame can be adjusted in the transverse direction, so as to meet the test requirements of flat specimens of different lengths.

[0042] In this embodiment, a first high temperature resistant nylon pad 130 is installed between the support plate 12 and the adjustment frame 11, a second high temperature resistant nylon pad 131 is installed at the contact part of the loading plate 15 and the rocker rod 16, and a third high temperature resistant nylon gasket 132 and a high temperature resistant nylon sleeve 133 are installed at the bolt position for the purpose of insulation.

[0043] In this embodiment, the heating system includes a heating furnace 8 which is covered on the outside of the fixed component and the heating component. The bottom of the heating furnace 8 is supported by a bracket 81 fixed on the top plate 7. The bottom of the heating furnace 8 is provided with a clearance hole for the upper end of the conjugate transmission component to pass through. The heating furnace 8 is provided with an internal circulation cooling component. The heating furnace is connected to the temperature control box to achieve test requirements under different temperature environments.

[0044] In this embodiment, the power assembly includes a power motor 4, the output shaft of the power motor 4 is connected to the power head 9 via a coupling 6, and the output shaft of the power head 9 is an eccentric spline shaft 91; a motor seat 3 is fixed to the left end of the base plate 2, and the power motor 4 is installed on the top of the motor seat 3. Further, the power motor is connected to a frequency converter to facilitate the adjustment of the experimental frequency.

[0045] In another embodiment, the frequency converter is also connected to the alarm module. When the power supply voltage of the device is insufficient, the frequency converter detects that the power supply voltage required by the power motor 4 is insufficient, and the frequency converter will not operate to protect the power motor 4, and alarm to provide fault information. When the device does not respond and does not operate when the device is started, that is, when the power motor 4 is in a fault state or cannot be started, the frequency converter will detect whether the power motor is in a normal state. When the power motor 4 is in the starting and running state, the frequency converter will synchronously detect the state of the power motor. If the power motor fails, the frequency converter will stop the operation of the power motor 4 to achieve the purpose of protecting the power motor 4. The fault of the power motor 4 is detected by the frequency converter and the fault information of the power motor 4 is displayed. The maintenance personnel will perform corresponding power motor 4 fault repairs according to the fault information detected by the frequency converter.

[0046] In another embodiment, a detection device is further included, and the detection device includes a proximity switch 5, an electronic counter and an automatic control relay. The proximity switch 5 is installed at the right end of the top surface of the motor base 3 and is located directly below the protruding bolt position of the coupling 6. The proximity switch 5 detects that the coupling 6 rotates one circle and outputs a high-potential signal to the electronic counter. During operation, the power motor 4 drives the coupling 6 to rotate when it rotates. The coupling 6 rotates one circle, and the protruding bolt on the coupling 6 passes through the proximity switch 5. The proximity switch 5 outputs a high-potential signal to the electronic counter. When the electronic counter receives the high-potential signal output by the proximity switch 5, it will count once.

[0047] The common signal line of the automatic control relay is installed in parallel with the low-level signal line on the support plate, and the high-level signal line of the automatic control relay is installed on the loading plate. When the automatic control relay detects that the common parallel line is disconnected from the high-level line, the counting channel of the proximity switch is cut off; since the counting channel is cut off, the electronic counter cannot receive the proximity switch 5 signal and will stop counting and keep the currently recorded value. At the same time, the automatic control relay is also connected to the PLC and the alarm module. Since the detection signal is cut off, the automatic control relay outputs a potential signal to the PLC. The PLC receives the output signal of the automatic control relay, and the PLC enters the internal counting stop program and sends a workstation completion instruction to stop the power motor 4 from rotating and send the instruction to the external control circuit relay. At this time, the external relay is turned on, and the control alarm module is started, prompting the operator that the workstation has completed the experiment.

[0048] In this embodiment, the eccentricity of the eccentric spline shaft 91 is 9 mm, the eccentricity of the inner eccentric wheel 101 is 4.4 mm, and the eccentricity of the outer eccentric wheel 102 is 2 mm. The end faces of the eccentric spline shaft 91, the inner eccentric wheel 101 and the outer eccentric wheel 102 are all engraved with marks to facilitate the test personnel to adjust the amplitude. The eccentricity and amplitude are in a similar triangle relationship, and the formula is:

[0049]

[0050] Where s is the specimen amplitude; e is the eccentricity; l is the distance from the free end of the flat specimen to the center of the hinged seat. Under the shape and size of the specimen, l=55mm; L is the center distance between the two holes of the rod, L=140mm.

[0051] In this embodiment, a vertically arranged upper shaft 104 is screwed in the middle of the top surface of the yoke 105, and the upper end of the upper shaft 104 is connected to the loading assembly through a rod end joint bearing 18. When the upper shaft 104 moves up and down, the loading assembly is driven to move through the rod end joint bearing 18; a vertically arranged lower shaft 107 is screwed in the middle of the bottom surface of the yoke 105, and the lower shaft 107 is slidably matched with a round flange linear bearing arranged at the right end of the bottom plate 2 of the frame to play a guiding role.

[0052] In this embodiment, when the axis connecting the end faces of the inner eccentric wheel 101 and the outer eccentric wheel 102 is 180° relative to each other, the angle ɑ between the end face axis of the eccentric spline portion 91 and the end face axis of the outer eccentric wheel 102 is adjusted to achieve the eccentricity and amplitude shown in the following table. At this time, the two holes on the connecting gasket 106 used correspond to the first connecting hole (located on the outer eccentric wheel 102) and the second connecting hole (located on the eccentric spline shaft 91), and the distance between the two holes is 21.6 mm.

[0053]

[0054] In this embodiment, when the axis line of the inner eccentric wheel 101 and the outer eccentric wheel 102 is 0° relative to the horizontal plane, the eccentricity and amplitude shown in the following table can be achieved by adjusting the angle ɑ between the end face axis of the eccentric spline part 91 and the end face axis of the outer eccentric wheel 102. At this time, the two holes on the connecting gasket 106 used correspond to the first connecting hole (located on the outer eccentric wheel 102) and the second connecting hole (located on the eccentric spline shaft 91), and the distance between the two holes is 30.4mm.

[0055]

[0056] In this embodiment, when the cantilever type flat plate reciprocating bending fatigue testing machine is working: first, the positional relationship between the inner and outer eccentric wheels and the eccentric spline shaft 91 is adjusted according to the amplitude required for the test; then the free end of the flat plate sample 19 is fixed to the loading plate 15, and the fixed end of the flat plate sample 19 is fixed to the support plate 12, and then the temperature control box is opened, the heating temperature of the heating furnace 8 is adjusted, and the power motor 4 is started. The rotational motion of the power motor 4 is converted into the up and down reciprocating linear motion of the conjugate transmission component 10, and the conjugate transmission component 10 drives the loading component to swing up and down, and the loading component drives the flat plate sample 19 to bend up and down; when the flat plate sample 19 breaks, the automatic control relay detects that the common parallel line is disconnected from the high-level line, and the counting channel of the proximity switch will be cut off. Since the counting channel is cut off, the electronic counter cannot receive the proximity switch signal and will stop counting and keep the currently recorded value. After the repeated bending fatigue test of the flat plate is stopped, the flat plate sample is removed after cooling, and the data on the electronic counter is recorded.

[0057] The advantages of the utility model are:

[0058] 1. The structure for adjusting the amplitude is special. The structure of eccentric spline shaft-inner and outer eccentric wheels is used to adjust the amplitude of the flat specimen. The rotational motion is converted into the up and down reciprocating motion of the upper shaft through the conjugate structure, and then the free end of the flat specimen is loaded, which has good reliability.

[0059] 2. It can meet the bending fatigue test of flat specimens of different lengths. By adjusting the different positions of the adjustment frame on the top plate or adjusting the position of the loading plate on the swing rod, the test requirements of flat specimens of different lengths can be met, thereby improving the flexibility of use;

[0060] 3. Equipped with a heating system, it can realize plate reciprocating bending fatigue tests at different temperatures, which is helpful for material fatigue life research in high temperature environments.

[0061] If the present invention discloses or involves components or structures that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using bolts or screws), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutual fixed connection can also be replaced by an integrated structure (for example, manufactured by one-piece molding using a casting process) (except where it is obviously impossible to use an one-piece molding process).

[0062] In addition, unless otherwise stated, the terms used to indicate positional relationships or shapes in any of the technical solutions disclosed in the above utility model include states or shapes that are approximate, similar or close thereto.

[0063] Any component provided by the utility model can be assembled from multiple separate components, or can be a separate component manufactured by an integrated molding process.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the utility model can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the utility model, which should be included in the scope of the technical solution for protection of the utility model.

Claims

1. A cantilever plate reciprocating bending fatigue testing machine, characterized in that: The machine comprises a frame, a heating system is arranged on the top plate of the frame, a fixing assembly for fixing the fixed end of a horizontally arranged flat sample is arranged inside the heating system, a loading assembly for connecting with the free end of the flat sample is arranged on the right side of the fixing assembly; a power assembly is arranged on the bottom plate of the frame, a power output end of the power assembly is connected with the loading assembly via a conjugate transmission assembly that can move back and forth vertically, and the power assembly drives the loading assembly to swing up and down through the conjugate transmission assembly to realize reciprocating bending of the flat sample.

2. A cantilever plate reciprocating bending fatigue testing machine according to claim 1, characterized in that: The conjugate transmission assembly includes a yoke, an eccentric spline shaft, an inner eccentric wheel, an outer eccentric wheel and a bearing. The yoke is arranged vertically, and a stepped through hole is arranged in the middle part of the yoke and runs through in the transverse direction. The eccentric spline shaft is arranged in the transverse direction and the spline portion extends into the stepped through hole. The inner eccentric wheel is provided with a spline hole matching with the spline portion of the eccentric spline shaft, and a limiting flange is arranged on the outer peripheral side of the left end of the inner eccentric wheel. The outer eccentric wheel is sleeved on the outer side of the inner eccentric wheel, and the right end face of the outer eccentric wheel is connected to the middle part of the right end face of the spline portion of the eccentric spline shaft through a connecting gasket. The bearing is sleeved on the outer side of the left end of the outer eccentric wheel, and the bearing is located between the limiting flange and the stepped surface of the stepped through hole and slidingly matches with the left end of the stepped through hole.

3. A cantilever plate reciprocating bending fatigue testing machine according to claim 2, characterized in that: The right end face of the outer eccentric wheel is provided with a first connecting hole near the edge, the middle part of the right end face of the spline part of the eccentric spline shaft is provided with a second connecting hole, and the two ends of the connecting gasket are respectively fixed by locking bolts matching the first connecting hole and the second connecting hole.

4. The cantilever plate reciprocating bending fatigue testing machine according to claim 2, characterized in that: A vertically arranged upper shaft is screwed in the middle of the top surface of the yoke, and the upper end of the upper shaft is connected to the loading assembly through a rod end joint bearing; a vertically arranged lower shaft is screwed in the middle of the bottom surface of the yoke, and the lower shaft is slidably matched with a round flange linear bearing arranged at the right end of the bottom plate of the frame.

5. The cantilever plate reciprocating bending fatigue testing machine according to claim 4, characterized in that: The loading assembly includes a pair of Z-shaped swing rods which are horizontally arranged and symmetrically distributed along the front and rear directions. The right ends of the pair of swing rods are connected by a joint, and the right end of the joint is hinged to the upper end of the rod end joint bearing; the left ends of the pair of swing rods are respectively hinged to the hinge seats fixed on the top plate through longitudinal hinge shafts, and a longitudinally arranged loading plate is fixed between the bottoms of the left ends of the pair of swing rods, and the free end of the flat sample is locked on the top surface of the loading plate.

6. The cantilever plate reciprocating bending fatigue testing machine according to claim 1, characterized in that: The fixing assembly comprises an adjustment frame fixed on the top surface of the top plate, a longitudinally arranged support plate is fixed on the top of the adjustment frame, and the fixed end of the flat sample is locked on the top surface of the support plate.

7. The cantilever plate reciprocating bending fatigue testing machine according to claim 5, characterized in that: The bottom of the left end of a pair of swing rods is provided with a plurality of first locking holes evenly spaced along the lateral direction and used to cooperate with the first bolt to lock the loading plate; the left end of the top plate is provided with a plurality of second locking holes evenly spaced along the lateral direction and used to cooperate with the second bolt to lock the adjustment frame.

8. The cantilever plate reciprocating bending fatigue testing machine according to claim 5, characterized in that: The power assembly includes a power motor, the output shaft of the power motor is connected to the input shaft of the power head via a coupling, and the output shaft of the power head is an eccentric spline shaft; a motor seat is fixed to the left end of the base plate, and the power motor is installed on the top of the motor seat.

9. The cantilever plate reciprocating bending fatigue testing machine according to claim 8, characterized in that: It also includes a detection device, which includes a proximity switch, an electronic counter and an automatic control relay. The proximity switch is installed at the right end of the top surface of the motor base and is located directly below the protruding bolt position of the coupling. The proximity switch outputs a high-potential signal to the electronic counter after detecting that the coupling rotates one circle; the common signal line and the low-level signal line of the automatic control relay are installed in parallel on the support plate, and the high-level signal line of the automatic control relay is installed on the loading plate. When the automatic control relay detects that the common parallel line is disconnected from the high-level line, the counting channel of the proximity switch is cut off.

10. The cantilever plate reciprocating bending fatigue testing machine according to claim 1, characterized in that: The heating system includes a heating furnace covered on the outside of the fixed component and the heating component. The bottom of the heating furnace is supported by a bracket fixed on the top plate. The bottom of the heating furnace is provided with a clearance hole for the upper end of the conjugate transmission component to pass through. The heating furnace is provided with an internal circulation cooling component, and the heating furnace is connected to the temperature control box.

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