CN112595613A - Device and method for testing bending fatigue performance of coating of piston rod of hydraulic cylinder - Google Patents
Device and method for testing bending fatigue performance of coating of piston rod of hydraulic cylinder Download PDFInfo
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Abstract
The invention discloses a device and a method for testing the bending fatigue performance of a coating of a piston rod of a hydraulic cylinder, wherein the device comprises a load applying system, a stress detecting system and a crack monitoring system; the load application system applies bending load to the coating area of the piston rod; the stress detection system detects the bending stress change of the coating area of the piston rod applied with the bending load; and the crack monitoring system monitors the corresponding bending fatigue times of the coating when the first coating of the coating area of the piston rod applied with the bending load is subjected to bending fatigue crack. Therefore, the test and evaluation of the bending fatigue resistance of the coating of the piston rod are realized, the problem of technical deficiency of the bending fatigue resistance test and evaluation of the coating of the surface of the piston rod of the hydraulic cylinder in the traditional design process is effectively solved, and the improvement of the working reliability and safety of the piston rod of the hydraulic cylinder in a severe environment is facilitated.
Description
Technical Field
The invention relates to the technical field of hydraulic cylinder coating performance evaluation, in particular to a device and a method for testing the bending fatigue performance of a coating of a piston rod of a hydraulic cylinder.
Background
The hydraulic cylinder is a hydraulic actuating element which converts hydraulic energy into mechanical energy and makes linear reciprocating motion, has the advantages of simple structure, reliable work and the like, and is widely applied to hydraulic systems of large equipment such as engineering machinery, marine equipment and the like. In the working process, the piston rod needs to perform frequent reciprocating telescopic motion, and the surface of the piston rod is in contact with the medium of the surrounding working environment for a long time. Meanwhile, because the large-scale equipment is in a severe working environment and generally contains corrosive media such as acid-base, high-salt and high-humidity, the surface of the piston rod is easy to lose effectiveness such as pitting corrosion and corrosion, and further faults such as oil leakage and clamping stagnation of the hydraulic cylinder are caused, and the working reliability and safety of the large-scale equipment are affected. Therefore, in engineering application, a corrosion-resistant functional coating is prepared on the surface of the piston rod by adopting a surface technology according to the actual use working condition requirement, so that the environmental adaptability of the piston rod is improved. Common coating types include electroplated chromium layers, hot sprayed WC and ceramic coatings, laser-clad corrosion-resistant metal coatings, and the like. Meanwhile, in order to improve the properties of wear resistance of abrasive particles, sand erosion, collision of hard objects and the like on the surface of the piston rod, the surface coating of the piston rod is required to have certain wear resistance and hardness. The hardness of the general electroplated chromium layer is more than or equal to 700HV, the hardness of the hot spraying WC coating is more than or equal to 1200HV, the hardness of the hot spraying ceramic coating is more than or equal to 1100HV, and the hardness of the laser cladding corrosion-resistant metal coating is more than or equal to 800 HV.
However, in actual use, the hydraulic cylinder needs to withstand the working load in addition to being in contact with the surrounding working medium. Under normal working conditions, the hydraulic cylinder mainly bears axial compression or tensile load, but also needs to bear frequent reciprocating lateral load under severe environments, for example, a suspension cylinder for engineering machinery needs to bear the lateral load caused by shaking of a vehicle body when a road surface bumps, and a maritime work hydraulic cylinder and a hydraulic cylinder need to bear frequent lateral impact of seawater and sea wind on the surface of the suspension cylinder. The cyclic reciprocating action of the side load causes cyclic reciprocating lateral bending of the piston rod during operation of the hydraulic cylinder and cyclic bending stress is generated inside the coating. Because the hardness of the piston rod coating is high, the toughness of the piston rod coating is generally relatively low, and the coating can generate bending fatigue failure and fatigue cracks along with the continuous accumulation of the cyclic bending stress. After the coating cracks, external corrosive media can easily penetrate into the matrix through the cracks and then generate corrosion reaction with the matrix to generate corrosion. More seriously, the fatigue fracture of the matrix can be caused, and accidents can be caused.
Therefore, by combining the analysis, the development of the bending fatigue resistance performance evaluation of the piston rod coating has important significance for improving the service reliability of the hydraulic cylinder in a severe environment. At present, related research documents and reports in China are few, a method for testing the bending fatigue resistance of the piston rod coating is not provided, and a related detection device is not developed at the same time, so that the bending fatigue resistance of the piston rod coating in a severe environment cannot be evaluated, the popularization and application of the coating are limited, and the service reliability and safety of a host are brought with greater risks.
Disclosure of Invention
The invention aims to provide a device and a method for testing the bending fatigue performance of a coating of a piston rod of a hydraulic cylinder, which effectively solve the problem of the technical defect of testing the bending fatigue resistance of the surface coating of the piston rod in the traditional design process and are beneficial to improving the working reliability and safety of the piston rod of the hydraulic cylinder in a severe environment.
The invention adopts the following technical scheme for realizing the aim of the invention:
the invention provides a device for testing the bending fatigue performance of a coating of a piston rod of a hydraulic cylinder, which comprises a load applying system, a stress detecting system and a crack monitoring system, wherein the load applying system is connected with the stress detecting system;
the load applying system is used for applying bending load to the coating area of the piston rod;
the stress detection system is used for detecting the bending stress change of the coating area of the piston rod applied with the bending load;
the crack monitoring system is used for monitoring the corresponding bending fatigue times of the coating when the bending fatigue cracks of the first coating of the coating area of the piston rod are applied with bending load.
Further, the load applying system comprises two bases for erecting the piston rods, and a loading device capable of regulating and controlling loading parameters is suspended above the bases.
Furthermore, a supporting seat is arranged on the base, two clamping blocks capable of moving in opposite directions or in a back-to-back direction are arranged on the supporting seat to fix the end part of the piston rod, and a first driving mechanism used for driving the two clamping blocks to move in opposite directions or in a back-to-back direction is connected to the supporting seat.
Furthermore, the supporting seat can be horizontally arranged on the base in a rotating mode through a connecting shaft.
Further, first actuating mechanism including set up in driving motor on the supporting seat, driving motor's output shaft is connected with one pair of dextrorotation lead screw left through drive mechanism, two the grip block corresponds threaded connection respectively in the both sides of dextrorotation lead screw left, and two grip block sliding connection in on the supporting seat.
Further, the loading device comprises an actuator hydraulic cylinder suspended above the base, and the output end of the actuator hydraulic cylinder is connected with a bending fatigue test pressure head.
Further, the bending fatigue test pressure head include with the output of actuator pneumatic cylinder rotates the loading fixing base of being connected, the bottom of loading fixing base is provided with the installation piece, but be provided with the compression roller of free rotation on the installation piece.
Furthermore, the number of the mounting blocks is two, the two mounting blocks are movably connected to the bottom of the loading fixing seat, and a second driving mechanism for driving the two mounting blocks to move in the opposite direction or in the opposite direction is connected to the loading fixing seat.
Furthermore, the stress detection system comprises a strain gauge which is used for being stuck to the surface of the coating of the maximum bending stress area of the piston rod, and the strain gauge is electrically connected with the strain test system.
Furthermore, the crack monitoring system comprises a reflection target spot for deformation monitoring, wherein the reflection target spot is used for being pasted on the maximum bending stress area of the piston rod, and the reflection target spot for deformation monitoring is electrically connected with the signal receiving device.
The invention also provides a method for testing the bending fatigue performance of the coating of the piston rod of the hydraulic cylinder, which comprises the following steps:
before the test is started, calculating to obtain the maximum value of the loading force required by the bending fatigue test according to the parameters of the piston rod;
determining a test load loading rule according to a stress change rule in the service process of the piston rod;
setting loading parameters based on a preset maximum loading force value and a loading rule, starting a load applying system, starting loading and recording related data in the test process;
detecting a bending stress change of a coating area of the piston rod applied with a bending load by a stress detection system;
monitoring the corresponding bending fatigue times of the first coating when the bending fatigue crack of the coating area of the piston rod is generated by a crack monitoring system;
and observing the surface crack condition of the piston rod coating, and further judging the bending fatigue resistance of the coating under a certain cycle number.
The invention has the following beneficial effects:
on one hand, the invention designs a device for testing the bending fatigue resistance of the coating of the piston rod of the hydraulic cylinder; on the other hand, the method for testing the bending fatigue resistance of the coating of the hydraulic cylinder piston rod integrates the functions of load regulation, stress detection, crack monitoring and fatigue resistance evaluation, so that the bending fatigue resistance of the coating of the piston rod is tested and evaluated, the problem that the bending fatigue resistance of the coating on the surface of the hydraulic cylinder piston rod is tested and evaluated in the traditional design process is effectively solved, and the working reliability and safety of the hydraulic cylinder piston rod in a severe environment are improved.
Drawings
FIG. 1 is a schematic diagram illustrating a bending fatigue performance test of a coating of a piston rod of a hydraulic cylinder according to an embodiment of the present invention;
FIG. 2 is a schematic view illustrating a loading process of a bending fatigue performance test of a coating of a piston rod of a hydraulic cylinder according to an embodiment of the present invention;
FIG. 3 is a schematic view of a device for testing bending fatigue performance of a coating of a piston rod of a hydraulic cylinder according to an embodiment of the present invention;
FIG. 4 is a schematic view of an assembly structure of the base and the V-shaped supporting seat in FIG. 3;
FIG. 5 is a schematic structural view of the V-shaped support seat shown in FIGS. 3 and 4;
FIG. 6 is a schematic structural diagram of the loading device in FIG. 3;
FIG. 7 is a first schematic structural view of the bending fatigue testing indenter of FIG. 3;
fig. 8 is a structural schematic diagram of the bending fatigue test indenter in fig. 3.
Detailed Description
The invention is further described with reference to specific examples. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
The invention provides a method for testing the bending fatigue resistance of a high-performance hydraulic cylinder piston rod coating in a severe environment and a special testing device, on one hand, a method for testing the bending fatigue resistance of the piston rod coating, which integrates load regulation, stress detection, crack monitoring and fatigue performance evaluation, is provided based on a three-point or four-point bending method, on the other hand, a special device for testing and evaluating the bending fatigue resistance of the coating, which is suitable for piston rods with different specifications, is designed, so that the bending fatigue resistance of the piston rod coating is tested and evaluated, the problem of technical deficiency of the bending fatigue resistance of the surface coating of the piston rod in the traditional design process is effectively solved, and the working reliability and safety of the hydraulic cylinder piston rod in the severe environment are improved.
The invention designs a coating bending fatigue resistance testing device capable of meeting the requirements of piston rods with different specifications, the whole structure of which is shown in figure 3 and mainly comprises a load applying system 10, a stress detecting system (a coating stress strain detecting system), a crack monitoring system (a dynamic deformation measuring system) and a piston rod 20.
The load applying system 10 adopts a hydraulic loading mode and mainly comprises a platform 11, a base 12, a V-shaped supporting seat 13, an upright post 14, a loading device 15, a supporting plate 16 and the like. The base 12 and the upright post 14 are fixed on the platform 11 through T-shaped bolts, and the loading device 15 is fixed on the upright post 14 through a support plate 16.
The V-shaped supporting seat 13 is mounted on the upper surface of the base 12 through the connecting shaft 17, the overall structure is as shown in FIG. 4, the V-shaped supporting seat 13 can rotate freely relative to the base 12, so that mounting errors between the bases 12 on two sides are compensated, and the V-shaped clamping block 132 and the piston rod 20 are uniformly stressed in the test process.
The structure of the V-shaped support base 13 is shown in fig. 5, and includes a fixing base 131, and a V-shaped clamping block 132, a driving motor 133, a bidirectional left-right screw rod 134, and the like are mounted on the fixing base 131. The driving motor 133 drives the screw rod 134 to drive the two V-shaped clamping blocks 132 to move in the same direction or in the opposite direction along the guide rail according to the requirement of the input signal, so as to meet the installation and support requirements of the piston rods 20 with different specifications. Meanwhile, the driving motor 133 also has a self-locking function, and when the V-shaped clamping block 132 moves to a designated position, the driving motor 133 locks the V-shaped clamping block, so that the test load is transmitted to the fixing seat 131.
The loading device 15 is constructed as shown in fig. 6, and mainly includes two parts, namely an actuator hydraulic cylinder 151 and a bending fatigue testing ram 152, wherein the actuator hydraulic cylinder 151 is connected with the support plate 16 and the bending fatigue testing ram 152 through an upper connecting ring 153 and a lower connecting ring 154 respectively. The actuator hydraulic cylinder 151 is connected with a hydraulic pump station, and integrates a hydraulic control system and an electric control system to further realize regulation and control of loading parameters such as loading load amplitude, frequency and the like. The bending fatigue testing ram 152 can freely rotate relative to the actuator hydraulic cylinder 151, so that the application force of the compression rollers at two sides to the surface of the piston rod is balanced, and the phenomenon of unbalanced application force is avoided.
The four-point bending press head structure is shown in fig. 7 and mainly comprises a connecting disc 1521, a loading fixing seat 1522, an installation block 1523, a press roller 1524, a driving motor 1525 and the like. The compression roller 1524 is mounted on the mounting block 1523 and can rotate freely, so that frictional resistance between the workpiece and the surface of the workpiece in the bending process is reduced. The mounting block 1523 is slidably mounted on the loading fixing seat 1522 and is connected with the driving motor 1525 through a screw rod. According to the requirements of test parameters, the driving motor 1525 drives the mounting block 1523 to slide through the screw rod so as to adjust the distance between the compression rollers 1524. The three point bending ram configuration under pulsating cyclic stress is shown in figure 8.
Before the test is started, the maximum value of the loading force required by the bending fatigue test is calculated according to the length, the diameter, the yield strength and other parameters of the piston rod. And determining a test load loading rule according to the stress change rule of the piston rod in the service process. And then, the strain gauge is adhered to the coating surface of the maximum bending stress area of the piston rod and is connected with a strain testing system through a data transmission line. Meanwhile, the light-reflecting target spot for deformation monitoring is adhered to the maximum bending stress area of the piston rod and is connected with a signal receiving device. In the test process, firstly, the distance between the V-shaped clamping blocks is adjusted according to the diameter of the piston rod, and the piston rod is placed above the V-shaped supporting seat. And then adjusting the distance between the press rolls on the two sides of the bottom of the loading device to a specified test parameter value. And setting parameters such as a loading force value, loading frequency, loading times and the like based on the preset maximum loading force amplitude and loading rule. And finally, starting the hydraulic pump station, starting loading and recording relevant data of the test process. And after the test is finished, observing the surface crack condition of the piston rod coating by using a microscope, and further judging the bending fatigue resistance of the coating under a certain cycle number.
The invention discloses a method for testing the bending fatigue resistance of a high-performance hydraulic cylinder piston rod coating in a severe environment.
(1) Test load regulation and control method
The invention designs a method for testing the bending fatigue performance of a piston rod coating based on a three-point bending method and a four-point bending method respectively, in the design process of a hydraulic cylinder, a designer fully considers the stress condition of a piston rod in the service process, and the type, the design size and the structure of a base material of the piston rod adopted ensure that the maximum bending stress borne by the piston rod is less than the allowable stress, otherwise the piston rod is subjected to permanent deformation to cause failure. Therefore, based on the stress condition of the piston rod base material under the actual working condition, in the bending fatigue performance test, the maximum bending stress of the base material under the action of the maximum test load is smaller than the allowable stress value.
Assuming that the yield strength of the piston rod base material is σsThe safety coefficient of the piston rod is S, the allowable stress [ sigma ] of the piston rod]Comprises the following steps: [ sigma ]]= σsand/S. Therefore, during the test loading process, the bending stress sigma of the piston rod base material is less than or equal to [ sigma ]] = σs/S。
When adoptingWhen the bending fatigue performance of the piston rod coating is tested by the three-point bending method, the stress analysis sketch is shown in fig. 1, and the maximum bending stress sigma = M borne by the piston rodmaxW, wherein the maximum bending moment Mmax= F/2 x y, piston rod bending resistance section coefficient W = pi D3/32. Substituting into a formula to obtain the maximum loading load value F not more than sigma in the test processs*πD3and/16S y. Wherein, F: total magnitude of test load, y: distance between the press roller and the supporting roller, D: the diameter of the piston rod.
The method can be obtained by the same calculation method, and when the bending fatigue performance of the piston rod coating is tested by adopting a four-point bending method, the maximum loading load value F is less than or equal to sigma in the test processs*πD3/16*S*y。
In the loading process, the stress ratio r can be set to be 0 or-1 according to the actual use working condition of the piston rod. When the stress borne by the piston rod in the using process is the pulsating cyclic stress, r = sigmamin/σmaxAnd = 0, a typical loading process is as shown in fig. 2 (a), and the loading method is that the ram is loaded to the maximum load value F according to a certain speed or a predetermined loading rule, then the ram is unloaded to the load value of 0, and then the ram is reloaded, and the cycle is continued until the specified number of tests. When the stress borne by the piston rod in the using process is symmetrical cyclic stress, r = sigmamin/σmaxAnd = 1, a typical loading process is as shown in fig. 2 (b), and the loading method is that the ram is loaded to the maximum load value F at a certain speed or according to a predetermined loading rule, then is unloaded to the load value of 0, then is loaded to the maximum load value-F in the opposite direction, then is unloaded to the load value of 0, and the cycle is continued until the specified number of tests.
(2) Method for detecting bending stress of coating
In the bending fatigue test process, the bending stress of the piston rod coating needs to be detected in real time, and the stress change process is recorded. On one hand, the problem that the test result is inaccurate due to overlarge loading force and overlarge stress caused by instability of a test system in the test process is solved. On the other hand, the stability of the bending fatigue resistance of the coating can be analyzed according to the stress change condition of the coating.
The invention provides a method for detecting the bending stress of the surface of a coating based on a stress-strain method, and a strain testing system is used for acquiring the change rule of the surface strain of the coating in real time. When the three-point bending method is adopted, the stress of the coating area of the piston rod acted by the press rollers is the largest, and when the four-point bending method is adopted, the coating area of the piston rod between the two press rollers is an equal stress area, and the coating bending stress of the area is the largest. Therefore, before testing, the strain gauge is adhered to the surface of the coating in the area with the largest stress, the strain gauge generates strain with the corresponding size along with the coating in the testing process, the strain change rule of the strain gauge can be tested through a strain testing system, the change rule of the strain epsilon of the coating along with the time in the testing process can be obtained, the elastic modulus E of the coating is known, and the change condition of the stress of the coating along with the time can be obtained through the formula sigma = E epsilon.
(3) Coating bending crack monitoring method
The monitoring of the bending fatigue crack of the coating aims to detect the corresponding bending fatigue times of the coating when the first fatigue crack occurs, and can also detect the generation condition of the crack on the surface of the coating in the test process.
The bending fatigue crack of the piston rod coating is generally a micro crack which can not be detected by naked eyes or a camera, and the micro crack on the surface of the coating can not be observed easily because the piston rod is always in a motion state in the test process and the focal length of the piston rod can not be adjusted by a microscope in real time. Therefore, the invention provides a coating surface crack monitoring method based on a dynamic deformation measurement system, and the technical problem that cracks cannot be monitored in the dynamic movement process is effectively solved. And pasting reflective target spots on the coating surface of the maximum bending stress area, and detecting the dynamic position coordinates of each target spot in real time by using a three-dimensional double CMOS camera measurement technology so as to analyze the strain change condition of the coating of the piston rod. If a significant stress concentration is detected in the coating during the test, it is indicated that cracks are formed on the surface of the coating.
(4) Method for testing bending fatigue performance of coating
After the bending fatigue of the coating of the piston rod reaches a certain number of times, fatigue cracks are generated on the surface of the coating, and the corrosion resistance of the piston rod is further influenced. Therefore, the invention provides the method for analyzing and evaluating the fatigue resistance of the coating by comparing and analyzing the indexes of the bending fatigue times of the coating, the existence of fatigue cracks on the surface, the number of the fatigue cracks, the length of the fatigue cracks and the like. The fatigue cracks were observed using a microscope at a magnification of about 10 to 50 times.
The invention provides a method for testing and evaluating the bending fatigue resistance of a piston rod coating, which integrates load regulation, stress detection, crack monitoring and fatigue resistance evaluation based on a three-point or four-point bending method.
The invention provides a piston rod coating bending fatigue stress detection method based on a strain gauge test method, which can accurately, quickly and low-cost detect the change condition of the coating bending fatigue stress.
The invention utilizes the dynamic deformation measurement system to realize the real-time monitoring of the bending fatigue crack of the coating, and solves the problem that the methods such as a camera, a microscope and the like can not realize the detection of the microscopic fatigue crack in the dynamic process.
The V-shaped clamping block supporting device designed by the invention can realize automatic and accurate adjustment of the distance by motor driving according to the diameter of the piston rod, thereby meeting the test requirements of piston rods with different specifications.
The bending fatigue resistance testing device for the piston rod coating can simulate the stress change rule of the piston rod under the actual working condition, set corresponding test load adjusting parameters and effectively improve the accuracy of test results.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.
Claims (11)
1. The device for testing the bending fatigue performance of the coating of the piston rod of the hydraulic cylinder is characterized by comprising a load applying system, a stress detecting system and a crack monitoring system;
the load applying system is used for applying bending load to the coating area of the piston rod;
the stress detection system is used for detecting the bending stress change of the coating area of the piston rod applied with the bending load;
the crack monitoring system is used for monitoring the corresponding bending fatigue times of the coating when the bending fatigue cracks of the first coating of the coating area of the piston rod are applied with bending load.
2. The device for testing the bending fatigue property of the coating of the piston rod of the hydraulic cylinder according to claim 1, wherein the load applying system comprises two bases for erecting the piston rod, and a loading device capable of regulating and controlling loading parameters is suspended above the bases.
3. The device for testing the bending fatigue property of the coating of the piston rod of the hydraulic cylinder according to claim 2, wherein the base is provided with a supporting seat, the supporting seat is provided with two clamping blocks which can move towards or away from each other simultaneously so as to fix the end of the piston rod, and the supporting seat is connected with a first driving mechanism for driving the two clamping blocks to move towards or away from each other.
4. The device for testing the bending fatigue property of the coating of the piston rod of the hydraulic cylinder according to claim 3, wherein the supporting seat is horizontally and rotatably arranged on the base through a connecting shaft.
5. The device for testing the bending fatigue property of the coating of the piston rod of the hydraulic cylinder according to claim 3, wherein the first driving mechanism comprises a driving motor arranged on the supporting seat, an output shaft of the driving motor is connected with a pair of left-right-handed screw rods through a transmission mechanism, the two clamping blocks are respectively and correspondingly screwed on two sides of the pair of left-right-handed screw rods, and the two clamping blocks are slidably connected on the supporting seat.
6. The device for testing the bending fatigue performance of the coating of the piston rod of the hydraulic cylinder according to claim 2, wherein the loading device comprises an actuator hydraulic cylinder suspended above the base, and an output end of the actuator hydraulic cylinder is connected with a bending fatigue testing pressure head.
7. The device for testing the bending fatigue performance of the coating of the piston rod of the hydraulic cylinder according to claim 6, wherein the bending fatigue testing pressure head comprises a loading fixing seat rotatably connected with the output end of the hydraulic cylinder of the actuator, a mounting block is arranged at the bottom of the loading fixing seat, and a freely rotatable compression roller is arranged on the mounting block.
8. The device for testing the bending fatigue performance of the coating of the piston rod of the hydraulic cylinder according to claim 7, wherein the number of the mounting blocks is two, the two mounting blocks are movably connected to the bottom of the loading fixing seat, and a second driving mechanism for driving the two mounting blocks to move in the opposite direction or in the opposite direction is connected to the loading fixing seat.
9. The coating bending fatigue performance testing device of the piston rod of the hydraulic cylinder as claimed in claim 1, wherein the stress detection system comprises a strain gauge adhered to the coating surface of the region with the largest bending stress of the piston rod, and the strain gauge is electrically connected with the strain testing system.
10. The device for testing the bending fatigue property of the coating of the piston rod of the hydraulic cylinder according to claim 1, wherein the crack monitoring system comprises a light-reflecting target spot for deformation monitoring, which is used for being stuck to a region with the largest bending stress of the piston rod, and the light-reflecting target spot for deformation monitoring is electrically connected with the signal receiving device.
11. A test method based on the device for testing the bending fatigue performance of the coating of the piston rod of the hydraulic cylinder according to any one of claims 1 to 10, is characterized in that,
before the test is started, calculating to obtain the maximum value of the loading force required by the bending fatigue test according to the parameters of the piston rod;
determining a test load loading rule according to a stress change rule in the service process of the piston rod;
setting loading parameters based on a preset maximum loading force value and a loading rule, starting a load applying system, starting loading and recording related data in the test process;
detecting a bending stress change of a coating area of the piston rod applied with a bending load by a stress detection system;
monitoring the corresponding bending fatigue times of the first coating when the bending fatigue crack of the coating area of the piston rod is generated by a crack monitoring system;
and observing the surface crack condition of the piston rod coating, and further judging the bending fatigue resistance of the coating under a certain cycle number.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011328543.8A CN112595613B (en) | 2020-11-24 | 2020-11-24 | Device and method for testing bending fatigue performance of hydraulic cylinder piston rod coating |
Applications Claiming Priority (1)
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| CN113484324A (en) * | 2021-06-30 | 2021-10-08 | 江苏徐工工程机械研究院有限公司 | Coating cracking resistance testing device and performance testing evaluation method |
| CN113514355A (en) * | 2021-04-23 | 2021-10-19 | 中国石油大学(华东) | Resonance bending fatigue testing machine for oil-gas pipe column |
| CN113514336A (en) * | 2021-07-22 | 2021-10-19 | 吉林大学 | Biaxial-loading weldment fatigue performance testing device and method |
| CN114383961A (en) * | 2021-12-30 | 2022-04-22 | 常州骏辉车辆配件有限公司 | Fatigue performance testing machine for piston rod detection |
| CN116773674A (en) * | 2023-08-23 | 2023-09-19 | 烟台星辉劳斯堡液压机械有限公司 | Device and method for testing bending fatigue performance of hydraulic cylinder piston rod coating |
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| CN116773674B (en) * | 2023-08-23 | 2023-11-03 | 烟台星辉劳斯堡液压机械有限公司 | Device and method for testing bending fatigue performance of hydraulic cylinder piston rod coating |
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