Dedicated integrated testing system for tensioners

Abstract

This invention discloses a dedicated integrated testing system for tensile testers, comprising a testing unit, a hydraulic pump, and a CNC unit. The testing unit is used to test the tensile tester and provide real-time feedback of test data. The hydraulic pump drives the tested hydraulic tensile tester and provides real-time feedback of the output pressure value. The hydraulic pump can be any type of hydraulic pump equipped with a pressure sensor to detect the output pressure. The CNC unit controls the working state of the hydraulic pump and receives and processes the test data fed back by the testing unit and the output pressure value fed back by the hydraulic pump. This invention, through the CNC unit of the dedicated integrated testing system for tensile testers, controls the operation of the hydraulic pump and the testing unit and generates a test report based on the feedback values. It can intuitively reflect whether the tensile tester is qualified, eliminate errors caused by manual processing, and make the test results more accurate.

Description

Technical Field

[0001] This utility model relates to the field of tensile testing technology, and in particular to a testing device for hydraulic tensile devices. Background Technology

[0002] A hydraulic tensioner is a specialized bolt preload tool. Bolt preload can be simply understood as the clamping force exerted by the bolt on the connected parts along the bolt's axial direction. Bolt preload is generated by the bolt being stretched within its elastic range. When using bolts to fasten parts, insufficient preload results in insufficient connection strength. Excessive preload may cause the bolt to break, or lead to the connected parts being crushed, stuck, twisted, deformed, or broken, or the threads being damaged by excessive shear force. The magnitude of the preload is a crucial factor affecting the reliability of bolted connections.

[0003] Currently, there are two main ways to control bolt preload: one is to control the torque applied to the nut using a torque wrench to achieve the purpose of controlling the preload; the other is to use a tensioner to apply a tension of the target preload magnitude to the bolt before tightening to achieve the purpose of controlling the preload.

[0004] While both methods show a positive correlation between torque and preload, there is no direct conversion between them. Factors such as the bolt material and specifications, as well as the surface roughness of the material being tightened, all affect the relationship between torque and preload. Therefore, controlling bolt preload with a torque wrench can result in a significant range of errors. Compared to a torque wrench, a tensioner can control bolt preload more accurately.

[0005] The principle of a hydraulic tensioner is as follows: a hydraulic pump is used as the power source, and a hydraulic cylinder is used as the driving device. The piston of the hydraulic cylinder is connected to the screw through a tension nut. Before tightening the nut, the tensioner is started to apply a tension force to the screw that is the same as the target preload, so that the bolt rod is stretched, and then the nut is tightened.

[0006] Under normal circumstances, the input oil pressure P, piston cross-sectional area S, and output tension F of a hydraulic tensioner satisfy the relationship F=PS. However, due to factors such as piston cross-sectional dimension errors, friction between the piston and the inner wall of the cylinder, sealing between the piston and the inner wall of the cylinder, sealing between the cylinder and the cylinder head, and sealing between the cylinder head and the piston connecting rod, there will be errors between the actual output tension and the rated output tension of the hydraulic tensioner. Therefore, newly assembled hydraulic tensioners need to undergo rigorous testing to ensure that their errors are within the specified range.

[0007] The basic principle of testing hydraulic tensioners is the same: a test screw is set up, and the hydraulic tensioner under test is used to stretch the test screw according to the calibrated input oil pressure. The tension force on the test screw is monitored by a sensor, and the measured tension F on the test screw is determined. 实 and the rated output tension F corresponding to the rated input oil pressure 标 Calculate the error rate: (F) 实 -F 标 ) / F 标 .

[0008] Factors affecting the test results of hydraulic tensioners include: the structural form of the testing device, the method for detecting the tensile force on the test bolt, and the air inside the hydraulic cylinder of the tensioner. Among these, the structural form of the testing device and the method for detecting the tensile force on the test bolt are two main research directions for improving the accuracy of hydraulic tensioner tests. However, the impact of air inside the hydraulic cylinder of the tensioner on the test results has received little attention and research.

[0009] Newly assembled hydraulic tensioners often have air filling the cylinders and inlet / outlet channels. Since air is much more compressible than the hydraulic medium, during pressurization, the air in the cylinders gradually merges into the hydraulic medium. As the pressure increases, the rate of air merging changes, causing fluctuations in the hydraulic system's pressure values. This can distort the sampled hydraulic values ​​during testing, affecting the accuracy of the results. Therefore, before testing a new hydraulic tensioner, air must be purged to ensure accurate results. The principle is to pressurize the tensioner, forcing air out of the hydraulically sealed gaps in the cylinders. Currently, air purging of hydraulic tensioners relies solely on the experience of the testing operator, which is insufficiently accurate.

[0010] Furthermore, existing tensile testing devices require recording the hydraulic pump output pressure and the measured tensile force on the test screw for each pressurization, followed by manual calculation of the test results. This results in low automation, cumbersome operation, and a long testing process. Summary of the Invention

[0011] The purpose of this invention is to build a complete integrated testing system for hydraulic tensioners based on existing hydraulic tensioners and computer and control technology. This system can automatically complete pressurization, recording, calculation, output results, and store test data.

[0012] A dedicated integrated testing system for tensioners, including: The test unit is used to test the tensile test object and provide real-time feedback of test data. A hydraulic pump is used to drive the hydraulic tensioner under test and provide real-time feedback of the output pressure value. The hydraulic pump can be any type of hydraulic pump equipped with a pressure sensor to detect the output pressure.

[0013] The numerical control unit is used to control the working state of the hydraulic pump and to receive and process the test data fed back by the test unit and the output pressure value fed back by the hydraulic pump.

[0014] The test unit can be any existing tensile test device, such as the cylinder-based tensile test device disclosed in the invention patent application with publication number CN113804549A, or the pressure sensor-based tensile test device disclosed in the utility model patent with publication number CN212988673U.

[0015] The test unit may include one set of tensile testing devices, or two or more sets of tensile testing devices.

[0016] The numerical control unit includes a control module, a data processing module, and a storage module. The control module is used to control the operating status of the hydraulic pump. The storage module is used to store parameter information of the tensile tester (including the tensile tester model and tensile force parameters), as well as current test data and historical test reports. The data processing module is used to receive the test data of the test unit and the output pressure data of the hydraulic pump in real time, and generate a test report based on the test data of the test unit, the output pressure data of the hydraulic pump, and the corresponding tensile parameters in the storage module.

[0017] Furthermore, the hydraulic pump is preferably a double-acting hydraulic pump, including a high-pressure working port and a low-pressure working port, using a servo motor as the power unit, and using a solenoid valve to switch the output of the high-pressure working port or the low-pressure working port. The control module includes a motor control signal output interface for connecting to the controller of the servo motor and a solenoid valve control signal output interface for connecting to the solenoid valve of the hydraulic pump.

[0018] Specifically, the data processing module calculates the theoretical tensile value based on the theoretical pressure value and tensile parameters, calculates the error based on the measured tensile value and the theoretical tensile value, and generates a test report based on the theoretical tensile value, theoretical pressure value, measured tensile value, measured pressure value and error.

[0019] Furthermore, the CNC unit also includes an input / output device for interacting with the user. The input / output device can be a touch screen that integrates input and output, or it can be a combination of independent input and output devices. The input device can be one or more of the following: keyboard, mouse, touchpad, barcode scanner, etc. The output device can be one or more of the following: monitor, printer, projector, etc., which can output report content.

[0020] Furthermore, the CNC unit also includes a communication module for communicating with a remote server or device. This allows users to remotely access or control the testing system via computers, mobile phones, or other devices, read testing reports, or for the testing system to obtain parameter information of the tensile tester from a remote server.

[0021] Furthermore, a hydraulic cylinder-based tensile testing device is preferably used, wherein the data processing module calculates the measured tensile force value (the tensile force value on the test screw) based on the pressure value output by the pressure sensor and the cross-sectional area of ​​the test cylinder.

[0022] Furthermore, the testing system also includes a cabinet, which contains a hydraulic chamber for placing or installing the hydraulic pump, an input chamber for placing or installing input devices, a test chamber for placing or installing the tensile testing device, and a data chamber for placing or installing the CNC unit circuit board and display. The input chamber has symmetrically positioned sliding rails on its left and right inner walls, and a tray for placing input devices such as a keyboard and mouse is fixedly connected between these sliding rails. The test chamber is divided into upper and lower halves by a horizontal partition. The upper half is the tensile testing operation room, and the part of the testing device used to connect to the tensile tester is located in the upper half.

[0023] Furthermore, the testing chamber is equipped with two testing stations, each with a set of tensile testing devices (two testing stations on the left and right: a first testing station and a second testing station, each equipped with a first testing device and a second testing device, respectively). The two sets of tensile testing devices have different applicable tensile force ranges. By setting up two sets of tensile testing devices with different applicable tensile force ranges, it is convenient to test tensile testers of different specifications without the need to disassemble and replace the testing devices.

[0024] Furthermore, the bottom of the lower half of the test chamber is provided with a storage box for storing test screws of different specifications used for the tensile testing device.

[0025] Furthermore, the cabinet includes a top plate, a bottom plate, side plates, and partitions. The top plate, bottom plate, side plates, and partitions are welded or bolted together to form the outer shell of the cabinet, separating the hydraulic chamber, the input chamber, the testing chamber, and the data chamber. The upper half of the testing chamber is fitted with two sliding protective doors, and the lower half is fitted with two double-leaf doors. The sliding protective doors effectively prevent the test screw, tension sleeve, or other tensioned components from breaking and ejecting from the operating room, thus protecting personnel. The doors in the lower half facilitate the maintenance and repair of the testing device, and also allow for the use of the space below the testing platform as storage space.

[0026] Furthermore, four evenly distributed casters are fixed to the lower end face of the base plate to facilitate the movement of the cabinet.

[0027] To ensure rigorous and accurate test results and to avoid the influence of air in the tensioner's cylinder on the test results, the above-mentioned integrated testing system for tensioners should be purged of air according to the following steps before testing: Step S1: Start the hydraulic pump to pressurize the hydraulic tensioner, monitor the real-time output pressure of the hydraulic pump, and when the test pressure is reached, stop the hydraulic pump output and return the oil.

[0028] Step S2: Calculate the oil pressure fluctuation rate Q in the rapid pressure rise segment of the oil pressure waveform. If the oil pressure fluctuation rate Q is greater than the preset oil pressure fluctuation rate threshold Q', repeat step S1. If the oil pressure fluctuation rate Q is less than or equal to the preset oil pressure fluctuation rate threshold Q', the air purging is complete.

[0029] The oil pressure fluctuation rate Q refers to the percentage of the number of sampling points (time points) M where the oil pressure fluctuation difference C is greater than the preset oil pressure fluctuation difference threshold C', relative to the total number of sampling points N-2n for which the oil pressure fluctuation difference is calculated: M / (N-2n)*100%; where N is the total number of oil pressure sampling points in the rapid pressurization section, and 2n is the number of sampling points for which the fluctuation difference is not calculated.

[0030] The oil pressure fluctuation difference C refers to the difference between the actual oil pressure sampled value P0 and the ideal oil pressure value P0' at the sampling point: C = |P0 - P0'|. As an alternative, the ideal hydraulic pressure value P0' can be calculated using the following formula: P0' = P1 + (P2 - P1) / 2 = (P1 + P2) / 2. In this formula, n hydraulic pressure samples adjacent to the target sampling point are taken as a group (the total number is 2n + 1, with n preferably 1 or 2). P1 is the first hydraulic pressure sample in this group, and P2 is the last hydraulic pressure sample in this group. (Since the above method cannot calculate the fluctuation difference between the first n and last n hydraulic pressure samples in the rapid pressure increase section, the fluctuation rate Nn calculated in this invention is used as the denominator. Because the pressure effect of air on the hydraulic system exists throughout the entire rapid pressure increase section, ignoring the 2n hydraulic pressure samples has little impact on the judgment result.) As an improvement, the ideal oil pressure value P0' can be calculated by the following formula: P0'=(P1+P2+…+Pm) / m, where m=2n + 1. Take the n oil pressure sample values ​​adjacent to the oil pressure sample value of the fluctuation difference to be calculated, and combine them with the oil pressure sample value of the fluctuation difference to form a group of continuous oil pressure sample values ​​with a total of m. Take the average value of this group of oil pressure sample values ​​as the ideal oil pressure value P0'.

[0031] Regarding how to determine the rapid pressure rise segment: you can refer to the content disclosed in patent No. 2021100782278, and determine the starting position of the rapid rise segment in the oil pressure waveform by calculating the waveform similarity.

[0032] Alternatively, based on the characteristics of the oil pressure waveform generated by the air purging method described in this invention, the slope comparison method can be used to determine the starting position of the rapid pressure boosting section (the first oil pressure sampling value of the rapid pressure boosting section).

[0033] Specifically: using the sampling time t as the x-axis and the oil pressure sampling value as the y-axis, draw an oil pressure waveform diagram, and calculate the slope at each sampling point one by one along the waveform curve from back to front.

[0034] Calculate the slope K of the sampling point corresponding to time t. t Time: Take the three time points t adjacent to time t before time t. -1 t -2 t -3 The oil pressure sampling values ​​are used to calculate the average value and the result is recorded as P. 前 Take the three adjacent time points t after time t. +1 t +2 t +3 The oil pressure sampling values ​​are calculated, and the average value is denoted as P. 后 Then follow formula K. t = (P 后 - P 前 ) / (t +2 - t -2 )calculate.

[0035] When the slope is equal to zero (due to the fluctuation of the sampled values, the calculated slope of the pressure balance section cannot be exactly equal to zero, but it is close to zero, so a threshold is set. When the calculated slope is less than this threshold, it is judged that the slope is equal to zero), the fourth time point t adjacent to the current time t is used. +4 The oil pressure sampling value is used as the first oil pressure sampling value in the rapid pressurization stage.

[0036] The beneficial effects of this invention are as follows: The integrated testing system for tensioners disclosed in this application can control the hydraulic pump and testing unit through a CNC unit to cooperate in providing feedback values ​​and generating test reports. This provides a direct indication of whether the tensioner under test is qualified, eliminating errors caused by manual processing and making the test results more accurate. To ensure safety during the testing process, the testing system is equipped with a complete cabinet, which not only allows for a reasonable layout of each work area but also prevents personnel injury from the breakage of the test piece. The air purging method effectively eliminates air from the cylinder of the hydraulic tensioner, preventing it from gradually merging into the hydraulic medium and causing pressure fluctuations in the hydraulic system. This eliminates the inaccuracy of judgment based on the experience of the testing operator, effectively ensuring the accuracy of the test results. Attached Figure Description

[0037] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Figure 1 This is a schematic diagram of a specific example of the integrated detection system of the present invention; Figure 2 This is a partial structural schematic diagram of a specific example of the integrated detection system of the present invention; Figure 3 This is a partial structural front view of a specific example of the integrated detection system of the present invention; Figure 4 This is a schematic diagram of the numerical control principle of the integrated detection system of the present invention; Figure 5 This is a schematic diagram of the structure of a test unit, which is a specific example of the integrated detection system of the present invention. Figure 6 This is a schematic diagram of the working principle of a hydraulic pump, which is a specific example of the integrated detection system of the present invention. Figure 7 It is a record table of measured data on the tension of the test screw and the output pressure of the hydraulic pump; Figure 8 This is a test report of a specific example of the integrated detection system of the present invention; Figure 9 This is a pressure rise curve of the hydraulic tensioner under theoretical conditions; Figure 10 This is a graph showing the actual pressure rise of the hydraulic tensioner when air is contained in the cylinder. Figure 11 This is a schematic diagram illustrating the calculation methods for fluctuation difference and slope; In the diagram: 101. Cabinet; 102. Data cavity; 104. Opening door; 115. Protective door; 116. Guide groove; 141. Top plate; 142. Side plate; 114. Sliding rail; 106. Tray; 117. Casters; 107. Bracket; 143. Base plate; 108. Storage box; 105. Test cavity; 140. Partition; 113. Input cavity; 112. Fixing plate; 109. Hydraulic pump; 130. Hydraulic cavity; 202. Test unit; 151. CNC unit; 152. Control module; 153. Storage module; 154. Data processing module; 155. CNC unit circuit board; 156. Motor control signal output interface; 157. Solenoid valve control signal output interface; 158. Hydraulic pump pressure signal receiver; 159. Tensioner pressure signal receiver; 120. Servo motor; 121. Two-position four-way solenoid valve; 122. Two-position two-way solenoid valve; 160. Hollow cylinder; 161. Clamping component; 162. Support plate; 164. Auxiliary fixing component; 165. Test screw; 166. Hydraulic piston; 167. Tensioner; 168. Transition component; 150. Plunger pair. Detailed Implementation

[0038] The integrated testing system for tensioners of the present invention will be further described with reference to the accompanying drawings.

[0039] like Figure 1 , Figure 2 and Figure 3 As shown, the detection system described in this example includes a cabinet 101. The cabinet 101 is divided into a hydraulic chamber 130, an input chamber 113, a test chamber 105, and a data chamber 102 by welding or bolting through a top plate 141, a bottom plate 143, side plates 142, and a partition 140. A vertical partition divides the test chamber 105 to the left side of the cabinet 101. Two parallel horizontal partitions divide the area to the right of the vertical partition into the data chamber 102, the input chamber 113, and the hydraulic chamber 130 from top to bottom. Two parallel guide grooves 116 are fixed between the side plates 142 and are respectively fixedly connected to the horizontal partitions and the top plate 141. Two protective doors 115 are slidably connected between the guide grooves 116. Below the guide grooves 116, there are hinged and symmetrically shaped opening and closing doors 104 that are hinged to the side plates 142. Four evenly distributed casters 117 are fixed on the lower end face of the bottom plate 143.

[0040] The input cavity 113 has symmetrically positioned sliding rails 114 on its left and right inner walls. A tray 106 is fixedly connected between the sliding rails 114, and a keyboard and mouse are placed on the upper surface of the tray 106.

[0041] like Figure 1-4As shown, a display and a CNC unit circuit board are installed in the data cavity 102. The CNC unit circuit board 155 is provided with a motor control signal output interface 156, a solenoid valve control signal output interface 157, a hydraulic pump pressure signal receiving port 158, and a tensioner pressure signal receiving port 159.

[0042] The control module 152 sends working instructions to the motor control signal output interface 156 and the solenoid valve control signal output interface 157. The pressure sensor in the hydraulic pump 109 transmits the pressure signal to the hydraulic pump pressure signal receiving port 158 ​​via a data line. The pressure sensor in the test unit 202 transmits the pressure signal to the tensioner pressure signal receiving port 159 via a data line. The hydraulic pump pressure signal receiving port 158 ​​and the tensioner pressure signal receiving port 159 feed the data back to the data processing module 154 and perform calculations together with the tensioner parameters transmitted from the storage module 153. The data processing module 154 displays the processed data in tabular form on the display and stores the data in the storage module 153.

[0043] A hydraulic pump 109 is placed inside the hydraulic chamber 130.

[0044] In this specific example, the hydraulic pump 109 selected is a double-acting hydraulic pump, such as... Figure 4 and Figure 6 As shown, the hydraulic pump includes a servo motor 120, a plunger assembly 150, a two-position four-way solenoid valve 121, and a two-position two-way solenoid valve 122. The control module 152 transmits control signals to the servo motor 120 via a motor control signal output interface 156. The lower end of the output shaft of the servo motor 120 extends through the top cover of the oil tank into the inner cavity of the oil tank. A cam for the plunger assembly 150 is installed at the lower end of the output shaft of the servo motor 120. The oil outlet of the plunger assembly 150 communicates with the oil outlet of the pump body valve assembly. The control module 152 can also transmit control signals to the two-position four-way solenoid valve 121 and the two-position two-way solenoid valve 122 via a solenoid valve control signal output interface 157. Switching between the high-pressure and low-pressure working ports, the outlet of the plunger assembly 150 is connected to the inlet of the two-position four-way solenoid valve 121, the return port of the two-position four-way solenoid valve 121 is connected to the return pipeline, the inlet of the two-position two-way solenoid valve 122 is connected to the first working port of the two-position four-way solenoid valve 121, and the outlet of the two-position two-way solenoid valve 122 is connected to the return pipeline. The outlet of the plunger assembly 150 is unidirectionally connected to the high-pressure working port through the high-pressure output pipeline, and the high-pressure working port is unidirectionally connected to the oil tank through the return pipeline. The second working port of the two-position four-way solenoid valve 121 is connected to the low-pressure working port and is connected to the inner cavity of the oil tank through the hydraulic control outlet.

[0045] The test chamber 105 is divided into upper and lower halves by a horizontal partition. A bracket 107 is fixed between the left and right walls of the lower half. Two fixing plates 112, positioned left and right, are installed on the upper surface of the bracket 107. Test units 202 with different parameters are fixedly installed on the fixing plates 112 and the upper horizontal partition, respectively. A storage box 108 for storing test screws of different specifications is provided in the lower half. The test units 202 with different parameters can expand the applicability of the test screws and improve the testing efficiency.

[0046] In this specific example, the test unit 202 selected is a hydraulic cylinder-based tensile testing device, such as... Figure 5 As shown, the test unit 202 includes a hollow cylinder 160, a test screw 165, a clamping member 161, a tensioner 167, and a support plate 162. The hollow cylinder 160 is fixedly connected to the horizontal partition 140 by a nut. A hydraulic piston 166 is slidably connected inside the hollow cylinder 160. The upper end face of the hydraulic piston 166 is pressed against the tensioner 167 through a transition member 168. Hydraulic oil can be injected into the hollow cylinder 160 to press the tensioner 167 upward. The tensioner 167 acts on the test screw 165 and stretches it upward. The pressure sensor in the test unit 202 transmits the pressure signal to the tensioner pressure signal receiving port in the CNC unit circuit board 155 through a data line.

[0047] Test unit 202 also includes auxiliary fixing component 164, which is fixedly connected to fixing plate 112 by nuts. Support plate 162 is located directly below clamping member 161 and is pressed against it. Clamping member 161 is detachably connected to the lower end of test screw 165 and cooperates with hollow cylinder 160.

[0048] When the testing work begins, (1) The testing personnel use a handheld barcode scanner to scan the model of the tensile tester to be tested. The CNC unit will retrieve the model and tensile parameters of the tensile tester stored in the storage module, and then fix the tensile tester to be tested in the cabinet 101 and close the protective door 115. (2) The inspector pulls out the tray 106 and sends a test command to the CNC unit 151 via the input keyboard; (3) The control module 152 controls the hydraulic pump 109 to start. During the process of the hydraulic pump 109 output pressure rising, it takes three sets of output pressure data of the hydraulic pump 109 at the set pressure value of 40MPa and feeds the data back to the data processing module 154 to calculate the average measured pressure value. The average measured pressure value is calculated in the same way at set pressure values ​​of 50MPa, 60MPa, 70MPa, 80MPa, 90MPa, and 100MPa. The sampled values ​​are as follows: Figure 7 As shown in the first, third, and fifth columns, the data processing module 154 calculates the theoretical tensile force value using the tensile force parameters of the corresponding tensioner stored in the storage module 153. (4) As the output pressure of the hydraulic pump 109 increases, the pressure on the test screw 165 also increases. The average value of the pressure values ​​output by three pressure sensors is calculated when the set pressure values ​​are 40MPa, 50MPa, 60MPa, 70MPa, 80MPa, 90MPa, and 100MPa. Then, the tension value received by the test screw 165 is calculated based on the cross-sectional area of ​​the test cylinder. The results are as follows: Figure 7 As shown in columns two, four, and six; (5) The data processing module 154 calculates the average error and maximum error based on the measured tensile force and the theoretical tensile force, and generates a test report based on the set pressure, theoretical tensile force, average measured tensile force, average measured pressure, maximum error, and average error, such as Figure 8 As shown; (6) The test report will be displayed on the monitor and stored in the storage module 153 in the CNC unit 151.

[0049] Reference Figure 9-11 Under ideal conditions, the pressure change curve during a single pressurization process of the hydraulic tensioner is as follows: Figure 9 As shown, the pressurization process consists of three stages: the initial pressurization stage, the constant pressure stage, and the rapid pressurization stage.

[0050] The initial pressurization stage is when the oil pressure starts from 0 and continues until it reaches a level sufficient to overcome piston resistance and gravity. During this stage, the hydraulic tensioner piston is stationary, and the pressure gradually increases. Once the pressure is sufficient to push the piston, the piston begins to move, and the pressure remains constant.

[0051] The constant pressure section is the phase from the start of piston movement to the end of the no-load stroke. During this phase, the piston is unloaded and has not yet begun to stretch the test screw; the pressure inside the cylinder remains constant.

[0052] The rapid pressure increase phase occurs after the piston begins to stretch the test screw. During this phase, as the tension on the test screw increases, the pressure inside the cylinder rises rapidly.

[0053] However, in reality, due to the presence of air within the hydraulic cylinder, during the rapid pressurization phase, under high pressure, the air dissolves into the hydraulic fluid, causing the internal pressure of the hydraulic system to fluctuate and rise. For example... Figure 10 As shown.

[0054] Reference Figure 11Assuming the oil pressure sampling values ​​at time points t-1, t-2, t-3, t, t+1, t+2, and t+3 are P1, P2, P3, P4, P5, P6, and P7 respectively, according to the air purging method described in this invention, the fluctuation difference Ct at time point t is Ct = |P4 - [(P1 + P2 + P3 + P4 + P5 + P6 + P7) / 7]|. The slope at time point t is Kt = [(P5 + P6 + P7) / 3 - (P1 + P2 + P3) / 3)] / (t+2 - t-2).

[0055] The above description provides one or more embodiments in conjunction with specific content, and does not imply that the specific implementation of this application is limited to these descriptions. Any methods or structures that are similar to or identical to those of this application, or any technical deductions or substitutions made based on the concept of this application, should be considered within the scope of protection of this application.

Claims

1. A dedicated integrated testing system for tensioners, characterized in that, include: The test unit is used to test the tensile test object and provide real-time feedback of test data. A hydraulic pump is used to drive the hydraulic tensioner under test and provide real-time feedback of the output pressure value. The hydraulic pump is any hydraulic pump equipped with a pressure sensor to detect the output pressure. The numerical control unit is used to control the working state of the hydraulic pump and to receive and process the test data fed back by the test unit and the output pressure value fed back by the hydraulic pump. The numerical control unit includes a control module, a data processing module, and a storage module. The control module is used to control the working status of the hydraulic pump; The hydraulic pump is a double-acting hydraulic pump, including a high-pressure working port and a low-pressure working port. It uses a servo motor as a power unit and a solenoid valve to switch the output of the high-pressure working port or the low-pressure working port. The control module includes a motor control signal output interface for connecting to the controller of the servo motor and a solenoid valve control signal output interface for connecting to the solenoid valve of the hydraulic pump. The storage module is used to store parameter information of the tensile tester, current test data, and historical test reports. The parameter information includes the tensile tester model and tensile force parameters. The data processing module is used to receive the test data of the test unit and the output pressure data of the hydraulic pump in real time, and generate a test report based on the test data of the test unit, the output pressure data of the hydraulic pump and the corresponding tensile parameters in the storage module. The data processing module calculates the theoretical tensile value based on the theoretical pressure value and tensile parameters. The data processing module calculates the error based on the measured tensile value and the theoretical tensile value. Based on the theoretical tensile value, theoretical pressure value, measured tensile value, measured pressure value and error, the data processing module generates a test report. Before testing, perform air purging as follows: Step S1: Start the hydraulic pump to pressurize the hydraulic tensioner, monitor the real-time output pressure of the hydraulic pump, and when the test pressure is reached, stop the hydraulic pump output and return the oil. Step S2: Calculate the oil pressure fluctuation rate Q in the rapid pressure rise segment of the oil pressure waveform. If the oil pressure fluctuation rate Q is greater than the preset oil pressure fluctuation rate threshold Q', repeat step S1. If the oil pressure fluctuation rate Q is less than or equal to the preset oil pressure fluctuation rate threshold Q', the air purging is complete. The oil pressure fluctuation rate Q refers to the percentage of the number of sampling points M where the oil pressure fluctuation difference C is greater than the preset oil pressure fluctuation difference threshold C', out of the total number of sampling points N-2n for which the oil pressure fluctuation difference is calculated: M / (N-2n)*100%; where N is the total number of oil pressure sampling points in the rapid pressure boosting section, and 2n is the number of sampling points for which the fluctuation difference is not calculated. The oil pressure fluctuation difference C refers to the difference between the actual oil pressure sample value P0 and the ideal oil pressure value P0' at the sampling point: C=|P0-P0'|; The ideal oil pressure value P0' is calculated using the following formula: P0'=(P1+P2+…+Pm) / m, where m=2n + 1. The n oil pressure samples adjacent to the oil pressure sample value of the fluctuation difference being calculated are taken together with the oil pressure sample value of the fluctuation difference being calculated to form a group of continuous oil pressure samples with a total of m. The average value of this group of oil pressure samples is taken as the ideal oil pressure value P0'.

2. The integrated testing system for tensioners according to claim 1, characterized in that, The testing unit includes one, two, or more sets of tensile testing devices.

3. The integrated testing system for tensioners according to claim 1, characterized in that, The numerical control unit also includes an input / output device for user interaction. The input / output device is a touch screen with integrated input and output or a combination of independent input and output devices. The input device is one or more of the following: keyboard, mouse, touchpad, barcode scanner. The output device is one or more of the following: monitor, printer, projector, and other devices that can output report content. The numerical control unit also includes a communication module for communicating with a remote server or device.

4. The integrated testing system for tensioners according to claim 2, characterized in that, The aforementioned tensile testing device is a hydraulic cylinder-based tensile testing device, and the data processing module calculates the measured tensile force value based on the pressure value output by the pressure sensor and the cross-sectional area of ​​the test hydraulic cylinder.

5. The integrated testing system for tensioners according to claim 1, characterized in that, The testing system also includes a cabinet, which contains a hydraulic chamber for placing or installing the hydraulic pump, an input chamber for placing or installing an input device, a test chamber for placing or installing a tensile testing device, and a data chamber for placing or installing a CNC unit circuit board and a display. The input chamber has symmetrically positioned sliding rails on its left and right inner walls, and a tray for placing a keyboard and mouse input device is fixedly connected between the sliding rails. The test chamber is divided into upper and lower halves by a horizontal partition. The test chamber is equipped with two test stations, and each test station is equipped with a set of tensile testing devices. The two sets of tensile testing devices have different applicable tensile force ranges. The bottom of the lower half of the test chamber is equipped with a storage box for storing test screws of different specifications used for tensile testing devices.

6. The integrated testing system for tensioners according to claim 5, characterized in that, The cabinet includes a top plate, a bottom plate, side plates, and partitions. The top plate, bottom plate, side plates, and partitions are fixed together by welding or bolts to form the outer shell of the cabinet and to separate the hydraulic chamber, the input chamber, the test chamber, and the data chamber. The upper half of the test chamber is equipped with two sliding protective doors, and the lower half of the test chamber is equipped with two double-opening doors. The bottom plate is fixed with four omnidirectional wheels that are evenly distributed.

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