Device and method for measuring rigidity of table board of punching machine tool

Abstract

The invention provides a device and a method for measuring the rigidity of a punching machine table board, and belongs to the technical field of machine tool table board rigidity measurement. Comprising a test support, a displacement detection member and a loading structure. The four corners of the test support are connected with the four corners of a to-be-detected punching machine table top through cushion blocks. The loading structures are arranged at the middle part of a to-be-detected table board of the punching machine tool, and multiple groups of loading structures are arranged at intervals; the plurality of displacement detection members are arranged on the test support at intervals. The to-be-detected punching machine table top is pressurized through the loading structure, the deformation displacement generated by the to-be-detected punching machine table top in the loading process is detected through the displacement detection piece, and the test support is connected with the four corners of the to-be-detected punching machine table top only through the cushion blocks arranged at the four corners of the test support. Therefore, when the loading structure loads the table board of the punching machine tool to be detected, the test support will not deform along with the loading structure, and the detection precision of the displacement detection piece is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of machine tool table stiffness measurement, and relates to a measuring device and a measuring method for the stiffness of a stamping machine tool table. Background Art

[0002] In the manufacturing industry, as one of the important equipment, presses are widely used in the forming, stamping and processing of metal parts. The performance of a press not only depends on the design of its mechanical structure and transmission system, but is also closely related to the stiffness and stability of the workbench. The workbench bears huge loads during the pressurization process, so its stiffness characteristics are directly related to the stability of the production process and the quality of the final product.

[0003] The stiffness of the workbench refers to its ability to resist deformation under the action of external forces. Insufficient stiffness may cause elastic deformation of the workbench and the mold during the pressurization process, thus affecting the accuracy of the mold and the stamped parts. The positioning and fitting of the mold require high precision. If the stiffness of the workbench is insufficient, it will cause large deformation of the mold, resulting in problems such as out-of-tolerance dimensions of the stamped parts, affecting the life and reliability of the mold, etc.

[0004] During the mold design process, in order to ensure the rationality and processing accuracy of the mold, designers usually compensate for the deformation of the table according to manufacturing experience. At present, there is no reliable press stiffness data for reference. To improve the efficiency of surface compensation, it is necessary to perform surface compensation based on actual stiffness data. However, traditional stiffness measurement methods cannot provide sufficient accuracy and reliability. Compensating the die surface based on experience alone may lead to problems such as failure of mold trial, long mold repair time in the later stage, and increased development cycle.

[0005] In the prior art, a relatively accurate die surface compensation amount can be obtained through the finite element overall modeling analysis method for stamping. However, the use of the solid models of the upper and lower table surfaces of the press in the model results in a large number of model elements and a long calculation time, which does not meet the requirements of engineering applications. If simplified finite element models (such as using beam elements and shell elements to replace solid models) are used for the upper and lower table surfaces of the press, a relatively accurate die surface compensation amount can be obtained on the premise of reducing the number of elements and the calculation time. The simplified finite element model allows the use of press stiffness measurement data for calibration and verification, and allows the measurement of the deformation at multiple points under a certain load.

[0006] In summary, the prior art has problems such as insufficient accuracy, poor repeatability, and inability to monitor in real time in the measurement of the stiffness of the press workbench, thus unable to provide sufficient support for mold design. Therefore, there is an urgent need for a new precise measurement system to improve this situation. Through the method provided by the present invention, high-precision table stiffness data can be obtained under dynamic conditions, which is convenient for corresponding compensation during mold design, improves the fitting rate of the mold, and reduces the mold repair time and production cost. Summary of the Invention

[0007] The present invention aims to provide a high-precision and high-reliability stiffness measurement system and method for a press workbench, so as to solve the defects of traditional measurement techniques, provide a method capable of real-time monitoring and accurately calculating the stiffness of the press workbench, and improve the quality of the mold and thus the quality of stamped parts by combining means such as mold structure or finite element analysis with the stiffness of the tabletop.

[0008] The present invention provides a measuring device for the stiffness of a stamping machine tabletop, including a test bracket, a displacement detector, and a loading structure;

[0009] The four corners of the test bracket are connected to the four corners of the stamping machine tabletop to be detected through cushion blocks;

[0010] The loading structure is arranged at the middle part of the stamping machine tabletop to be detected, and there are multiple groups arranged at intervals, for applying pressure loading to the stamping machine tabletop to be detected;

[0011] The displacement detector has multiple pieces arranged at intervals on the test bracket, for measuring the deformation amount of the stamping machine tabletop to be detected during the loading process.

[0012] Further, the test bracket includes a first support beam and a second support beam;

[0013] There are two pieces of the first support beam arranged at intervals, and one end of the two first support beams is installed on the stamping machine tabletop to be detected;

[0014] There are at least two pieces of the second support beam arranged at intervals, and at least two pieces of the second support beam are installed on the other ends of the two first support beams far from the stamping machine tabletop to be detected, and a cross-shaped structure is formed horizontally between a single first support beam and a single second support beam.

[0015] Further, the loading structure includes support steel columns, hydraulic cylinders, and loading force test strain gauges arranged on the support steel columns;

[0016] There are multiple groups of the support steel columns, a single group of support steel columns is arranged between two adjacent second support beams, and a single group of support steel columns includes at least two support columns arranged at intervals. One end of a single support column is installed on the stamping machine tabletop to be detected, and the other end of the single support column extends in a direction away from the stamping machine tabletop along the vertical direction;

[0017] There are multiple hydraulic cylinders corresponding to the support columns one by one, and a single loading structure is installed on the end of the support column far from the test bracket;

[0018] The loading force test strain gauges are provided with multiple groups corresponding to the support columns one by one. Each group of loading force test strain gauges is provided with at least one unidirectional strain gauge installed along the central axis direction of the support column.

[0019] Furthermore, the test bracket is set as a structural member made of aluminum alloy.

[0020] Furthermore, the displacement detection component is set as a contact type high-precision displacement sensor, and the voltage signal output by the displacement sensor is set within 0 - 10V, and the measuring range is set as 0 - 2mm.

[0021] Furthermore, in addition to the above structure, the measuring device for the stiffness of the stamping machine tool table also includes a data collector. The data collector is simultaneously signal-connected to the loading force test strain gauges and the displacement detection component, and is used to receive the data collected by the displacement detection component and the loading force test strain gauges.

[0022] Furthermore, the data collector is set as a portable data collector. The portable data collector is internally provided with a shielded signal line, a transmission data line, and supporting software for storing, analyzing, and processing data.

[0023] The present invention also includes a method for measuring the stiffness of the stamping machine tool table, which includes the following steps:

[0024] Step 1: Assemble and debug the measurement of the stiffness of the stamping machine tool table as described above;

[0025] Step 2: Apply load;

[0026] Before starting the pressure application, start the portable data collector; and set the sampling frequency of the portable data collector to 100 - 150 times per second;

[0027] Drive the hydraulic cylinder in the loading structure to apply pressure to the stamping machine tool table to be detected. The applied load shall not exceed 75 - 80% of the rated load that the stamping machine tool table to be detected can withstand. After reaching its load pressure, hold the pressure for 5 - 10 seconds, and then release the pressure;

[0028] Step 3: Data analysis;

[0029] Process the real-time voltage signal collected by the portable data collector, and combine the applied pressure magnitude and the deformation amount to calculate the elastic deformation amount of the stamping machine tool table to be detected;

[0030] Process the strain signal collected by the portable data collector. According to the relationship between stress, strain, the pressure received by the support steel column, and the cross-sectional area, use the following formula to calculate the stiffness value F of the detected stamping machine tool table:

[0031] F = (ε1 - ε0) × E × πR 2 ;

[0032] Wherein, ε1 is the final value of the strain gauge for loading force test; ε0 is the initial value of the strain gauge for loading force test; E is the elastic modulus of the support steel column, and its value is 200 - 220 GPa; R is the radius of the cross-section of the support steel column.

[0033] Furthermore, the specific process of assembling and debugging the measurement of the stiffness of the stamping machine tool table is as follows:

[0034] Mark the placement positions for installing the support steel columns on the stamping machine tool table to be detected, and ensure that the placement positions of the support steel columns are symmetrically arranged along the central axis in the horizontal direction of the stamping machine tool table to be detected;

[0035] Install the loading force test strain gauges along the axial direction on the side of each support steel column, and then place one end of the connecting piece of the four support steel columns installed with the loading force test strain gauges at the marked positions on the stamping machine tool table to be detected;

[0036] Install hydraulic cylinders on each support steel column, and use a level to calibrate the positions of the hydraulic cylinders to ensure that each hydraulic cylinder is in a horizontal state;

[0037] After assembling the test bracket, place it on the stamping machine tool table to be detected, and place multiple annular cushion blocks between the first support beam and the stamping machine tool table to be detected to adjust the height of the test bracket, so as to ensure that the test bracket is in a horizontal state relative to the reference point on the stamping machine tool table to be detected; then relatively fix the test bracket and the stamping machine tool table to be detected through bolts to prevent the test bracket from shifting during the pressure test;

[0038] Install multiple displacement sensors at the positions corresponding to the second support beam and the support steel column respectively but do not lock and fix them;

[0039] Pre-press the displacement sensors to keep the initial voltage value at 4 - 6 V to ensure that the displacement sensors are within the working range;

[0040] Use a square to observe whether the current displacement sensor is perpendicular to the stamping machine tool table to be detected;

[0041] If the current displacement sensor is not perpendicular to the stamping machine tool table to be detected, fine-tune the current displacement sensor until the current displacement sensor is perpendicular to the stamping machine tool table to be detected, and then lock and fix the displacement sensor;

[0042] Use a square to observe in turn whether other displacement sensors are perpendicular to the tabletop of the stamping machine to be detected, and ensure that each displacement sensor is perpendicular to the tabletop of the stamping machine to be detected before locking and fixing.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] A measuring device for the stiffness of the tabletop of a stamping machine provided by the present invention includes a measuring bracket, a displacement detecting member, and a loading structure. The loading structure pressurizes the tabletop of the stamping machine to be detected, and the displacement detecting member detects the deformation displacement amount generated by the tabletop of the stamping machine to be detected during the loading process. The test bracket is only connected to the four corners of the tabletop of the stamping machine to be detected through the cushion blocks arranged at its four corners, so as to ensure that when the loading structure loads the tabletop of the stamping machine to be detected, the test bracket will not deform accordingly, so as to ensure the detection accuracy of the displacement detecting member.

[0045] In addition to the purposes, features, and advantages described above, the present invention has other purposes, features, and advantages. The following will refer to the drawings to further elaborate on the present invention in detail. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0047] Figure 1 is a

[0048] Wherein:

[0049] 1. Test bracket, 2. Support steel column, 3. Hydraulic cylinder, 4. Displacement sensor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] To make the above objects, features, and advantages of the present invention more clearly understood, the following will describe the specific embodiments of the present invention in detail with reference to the drawings. It should be noted that the drawings of the present invention are all in simplified forms and use non-precise scales, only for the convenience of clearly assisting in the description of the embodiments of the present invention; the several mentioned in the present invention are not limited to the specific quantities in the drawing examples; the orientation or positional relationships indicated by 'front', 'center', 'back', 'left', 'right', 'top', 'bottom','middle', etc. in the present invention are all based on the orientation or positional relationships shown in the drawings of the present invention, and do not indicate or imply that the devices or components referred to must have a specific orientation, nor can they be understood as a limitation to the present invention.

[0051] Embodiment:

[0052] See Figure 1 As shown, a stamping machine table stiffness measuring device provided by the present invention includes a test bracket 1, a displacement sensor 4, a loading driving member, a support steel column 2, a loading force test strain gauge, and a data collector arranged on the test bracket 1;

[0053] The test bracket 1 includes a first support beam and a second support beam. There are two pieces of the first support beam arranged at intervals. One ends of the two pieces of the first support beam are connected to the four corners of the stamping machine table to be detected through pads. There are at least two pieces of the second support beam arranged at intervals. At least two pieces of the second support beam are installed on the other ends of at least two pieces of the first support beam away from the stamping machine table to be detected, and each single-piece first support beam and each single-piece second support beam are arranged perpendicular to each other along the horizontal plane;

[0054] A plurality of the displacement sensors 4 are installed at intervals on each single-piece second support beam;

[0055] There are multiple groups of the support steel columns 2. A single group of the support steel columns 2 is arranged between two adjacent second support beams. Each single group of the support steel columns 2 includes at least two support columns arranged at intervals. One end of each single-piece support column is installed on the stamping machine table to be detected, and the other end of each single-piece support column extends in a direction away from the stamping machine table to be detected along the vertical direction;

[0056] There are multiple pieces of the loading driving members arranged corresponding to the support columns one by one, and each single-piece loading driving member is installed on the end of the support column away from the test bracket 1;

[0057] There are multiple groups of the loading force test strain gauges arranged corresponding to the support columns one by one. Each single group of the loading force test strain gauges includes at least one unidirectional strain gauge installed along the central axis direction of the support column;

[0058] The data collector is simultaneously signal-connected to the loading force test strain gauge and the displacement sensor 4, and is used to receive the data collected by the displacement sensor 4 and the loading force test strain gauge.

[0059] Preferably, the data collector is preferably set as a Beetest-1008 type portable data collector produced by Beijing BCT Technology Co., Ltd. This portable data collector is internally equipped with a shielded signal line, a transmission data line, and a supporting software for storing, analyzing, and processing data. The data collected by the displacement sensor 4 and the loading force test strain gauge are transmitted to this portable data collector through the shielded signal line for storage, analysis, and processing, and the calculation result of the stiffness of the stamping machine tool table is generated. Specifically, the input end of the displacement sensor is powered by a 12V regulated power supply, the output end of the displacement sensor is connected to the supporting software through the shielded signal line, and the signal collected by the loading force test strain gauge is a resistance signal, which is connected to the supporting software through the shielded signal line.

[0060] Preferably, the test bracket 1 is set as a structural member made of aluminum alloy.

[0061] Preferably, the support steel column 2 is preferably set as a cylindrical structure.

[0062] Preferably, a connecting member is further provided between the support steel column 2 and the support platform, and the connecting member is set as a square, rectangular, or polygonal structure whose inscribed circle is greater than or equal to the outer diameter of the support steel column 2.

[0063] Preferably, the displacement sensor is preferably set as a contact type high-precision displacement sensor, and the output voltage signal of the displacement sensor is set within 0-10V and the measuring range is set as 0-2mm.

[0064] The present invention also provides a method for measuring the stiffness of the stamping machine tool table by using the above-mentioned stamping machine tool table stiffness measuring device, including the following steps:

[0065] Step 1, preparation work;

[0066] In this embodiment, the support steel columns are preferably set as four pieces; mark the placement positions for installing the four support steel columns on the stamping machine tool table to be detected, and ensure that the placement positions of the four support steel columns are symmetrically arranged along the central axis in the horizontal direction of the stamping machine tool table to be detected;

[0067] Install a loading force test strain gauge at one end of each support steel column and a connecting member at the other end, and then place the connecting member end of the four support steel columns installed with the loading force test strain gauges at the marked positions on the stamping machine tool table to be detected;

[0068] Install a hydraulic cylinder on each support steel column, and use a level to calibrate the position of the hydraulic cylinder to ensure that each hydraulic cylinder is in a horizontal state;

[0069] After assembling the test bracket, place it on the workbench of the stamping machine to be tested, and place multiple annular cushion blocks between the first support beam and the workbench of the stamping machine to be tested to adjust the height of the test bracket, so as to ensure that the test bracket is horizontal relative to the reference point on the workbench of the stamping machine to be tested; then relatively fix the test bracket and the workbench of the stamping machine to be tested with bolts to prevent the test bracket from displacing during the pressure test.

[0070] Step 2: Install and calibrate the displacement sensor;

[0071] Pre-pressurize the displacement sensor to keep the initial voltage value at 4 - 6V to ensure that the displacement sensor is within the working range;

[0072] Use a square to observe whether the current displacement sensor is perpendicular to the workbench of the stamping machine to be tested;

[0073] If the current displacement sensor is not perpendicular to the workbench of the stamping machine to be tested, fine-tune the current displacement sensor until the current displacement sensor is perpendicular to the workbench of the stamping machine to be tested, and then lock and fix the displacement sensor;

[0074] Use a square to observe in turn whether other displacement sensors are perpendicular to the workbench of the stamping machine to be tested, and lock and fix each displacement sensor after ensuring that each displacement sensor is perpendicular to the workbench of the stamping machine to be tested.

[0075] Pre-pressurize the displacement sensor to keep the initial voltage value at 4 - 6V to ensure that the displacement sensor is within the working range; specifically, during the pre-pressurization of the displacement sensor, the data collector can be turned on to observe the output voltage of each displacement sensor in real time until each displacement sensor reaches the correct initial voltage value.

[0076] Step 3: Load application;

[0077] Connect a hydraulic pump to a four-way distribution valve to drive the hydraulic cylinder. During the pressurization process, ensure that the pressures of the four hydraulic cylinders are consistent through the four-way distribution valve, so as to eliminate local eccentric loading caused by unevenness;

[0078] Before the formal pressurization, check the stamping machine table stiffness measuring device to ensure that there is no mutual interference between the components of the stamping machine table stiffness measuring device;

[0079] Pressurize the hydraulic cylinder, and the applied load shall not exceed 80% of the rated load that the workbench of the stamping machine to be tested can withstand. After reaching the load pressure, hold the pressure for 5 seconds and then relieve the pressure;

[0080] Meanwhile, before starting the pressurization, start the portable data acquisition instrument to ensure the integrity of the records; set the data sampling frequency of the portable data acquisition instrument to 100 times per second to monitor the displacement changes of each point on the tabletop of the stamping machine tool to be detected in real time during the pressurization process, and store, analyze, and process the real-time data obtained from the monitoring.

[0081] Furthermore, to improve the measurement accuracy, repeat the pressurization and depressurization processes of the hydraulic cylinder 1 - 3 times, and take the average value as the reference data.

[0082] Step 4: Data analysis;

[0083] Process the real-time voltage signals collected by the portable data acquisition instrument, and combine the applied pressure magnitude and the deformation amount to calculate the elastic deformation amount of the tabletop of the stamping machine tool to be detected.

[0084] Specifically, assume that the displacement sensor is a voltage-type sensor, and its voltage range is 0 - 10V, and the displacement corresponding to 1V is 0.25mm. Then, the calculation formula for the elastic deformation amount d of the tabletop of the stamping machine tool to be detected during the pressurization process is as follows:

[0085] d = (V2 - V1) × 0.25;

[0086] Wherein, V2 is the output voltage of the displacement sensor during pressure holding, and V1 is the initial voltage of the displacement sensor.

[0087] Process the strain signals collected by the portable data acquisition instrument, and according to the relationship between stress, strain, the pressure received by the support steel column, and the cross-sectional area, use the following formula to calculate the loading force F (i.e., the stiffness value of the tabletop of the stamping machine tool to be detected) of the tabletop of the stamping machine tool to be detected:

[0088] F = (ε1 - ε0) × E × πR 2 ;

[0089] Wherein, ε1 is the final value of the strain gauge for loading force testing, ε0 is the initial value of the strain gauge for loading force testing, E is the elastic modulus of the support steel column (its value is preferably 210GPa), and R is the radius of the cross-section of the support steel column.

[0090] Through the above implementation solutions, a device and a measurement method for measuring the stiffness of the tabletop of a stamping machine tool provided by the present invention can accurately obtain the loading force (stiffness value) and its deformation amount of the tabletop of the stamping machine tool to be detected, that is, it can be used as a direct reference for the deformation compensation of the tabletop of the stamping machine tool, and can also correct the stamping finite element model through experimental data, fully consider the deformation of the press and the die surface, thereby realizing the overall simulation of the stamping production line and predicting the deformation situation of the die surface.

[0091] As a further embodiment of the present invention, taking the measurement of the lower table surface of a 500T press as an example, it is assumed that the output voltage values of multiple displacement sensors are collected at a rate of 100 times per second; it is assumed that the displacement sensors are provided with three groups spaced apart from each other, and each group is provided with 6 pieces spaced apart from each other. The first group of displacement sensors are respectively labeled as A1, A2, A3, A4, A5, and A6, the second group of displacement sensors are respectively labeled as B1, B2, B3, B4, B5, and B6, and the DG group of displacement sensors are respectively labeled as C1, C2, C3, C4, C5, and C6; the data collected by multiple sensors and the loading force of the hydraulic cylinder are automatically read, and the displacement amounts of the multiple displacement sensors specifically calculated are shown in Table 1.

[0092] Table 1: Test Results (Displacement Amount) of the Lower Table Surface of a 500T Press

[0093]

[0094] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A device for measuring the rigidity of a punching machine table, characterized in that: It comprises a test bracket (1), a displacement detection member and a loading structure; The four corners of the test bracket (1) are connected to the four corners of the table of the punching machine to be tested through pads; The loading structure is arranged on the middle part of the table of the stamping machine to be tested, and is provided with a plurality of groups arranged at intervals from each other, and is used to perform pressure loading on the table of the stamping machine to be tested; The displacement detection member is provided with a plurality of members which are arranged on the test bracket (1) at intervals from each other and are used to measure the deformation amount of the table of the punching machine tool to be detected during the loading process.

2. The device for measuring the rigidity of a punching machine table according to claim 1, characterized in that: The test stand (1) comprises a first support beam and a second support beam; The first support beam is provided with two pieces spaced apart from each other, and one end of the two first support beams is mounted on the table of the stamping machine to be tested; The second support beam is provided with at least two pieces which are spaced apart from each other, and at least two second support beams are installed on the other end of the two first support beams away from the table of the stamping machine to be inspected, and a cross structure is formed between a single first support beam and a single second support beam along a horizontal plane.

3. The device for measuring the rigidity of a punching machine table according to claim 1, characterized in that: The loading structure comprises a supporting steel column (2), a hydraulic cylinder (3) and a loading force testing strain gauge arranged on the supporting steel column (2); The support steel columns (2) are provided in a plurality of groups, a single group of support steel columns (2) is arranged between two adjacent second support beams, and the single group of support steel columns (2) comprises at least two support columns arranged at intervals from each other, one end of the single support column is mounted on the table of the stamping machine to be inspected, and the other end of the single support column is extended in a vertical direction away from the table of the stamping machine to be inspected; The hydraulic cylinder (3) is provided with a plurality of pieces arranged in one-to-one correspondence with the support columns, and a single-piece loading structure is installed on an end of the support column away from the test bracket (1); The loading force test strain gauges are provided with multiple groups arranged in one-to-one correspondence with the support columns, and a single group of loading force test strain gauges is provided with at least one unidirectional strain gauge installed along the central axis direction of the support column.

4. The device for measuring the rigidity of a punching machine table according to claim 1, characterized in that: The test bracket (1) is configured as a structural member made of aluminum alloy.

5. The device for measuring the rigidity of a punching machine table according to claim 1, characterized in that: The displacement detection element is configured as a contact type high-precision displacement sensor, and the output voltage signal of the displacement sensor is configured within 0-10V and the measuring range is configured to be 0-2mm.

6. The device for measuring the rigidity of a punching machine table according to any one of claims 1 to 5, characterized in that: It also includes a data collector, which is connected to the load force test strain gauge and the displacement detection member by signals and is used to receive data collected by the displacement detection member and the load force test strain gauge.

7. The device for measuring the rigidity of a punching machine table according to claim 6, characterized in that: The data collector is configured as a portable data collector, which has built-in shielded signal lines, data transmission lines, and supporting software for storing, analyzing, and processing data.

8. A method for measuring the rigidity of a punching machine table, characterized in that: The following steps are involved: Step 1, assembling and debugging the measurement of the table top rigidity of the stamping machine as claimed in claim 7; Step 2: Load application; Before the pressurization begins, start the portable data acquisition instrument; and set the sampling frequency of the portable data acquisition instrument to 100-150 times / second; Drive the hydraulic cylinder in the loading structure to pressurize the table of the stamping machine to be tested. The loaded load shall not exceed 75-80% of the rated load that the table of the stamping machine to be tested can bear. After reaching the load pressure, maintain the pressure for 5-10 seconds and then release the pressure; Step 3: Data analysis; The real-time voltage signal collected by the portable data acquisition instrument is processed, and the elastic deformation of the table of the punching machine to be tested is calculated by combining the applied pressure and deformation. The strain signal collected by the portable data acquisition instrument is processed, and the stiffness value F of the tested stamping machine table is calculated using the following formula according to the relationship between stress, strain, pressure on the supporting steel column and the cross-sectional area: F=(ε1-ε0)×E×πR 2 ; Among them, ε1 is the final value of the load force test strain gauge; ε0 is the initial value of the load force test strain gauge; E is the elastic modulus of the supporting steel column, which is 200-220GPa; R is the radius of the cross section of the supporting steel column.

9. The method for measuring the rigidity of a punching machine table according to claim 8, characterized in that: The specific process of assembling and debugging the measurement of the table stiffness of the stamping machine is as follows: Mark the placement position for installing the support steel column on the table of the stamping machine to be tested, and ensure that the placement position of the support steel column is symmetrically arranged along the central axis of the horizontal direction of the table of the stamping machine to be tested; A load force test strain gauge is installed on one end of each support steel column, and then one end of the connecting piece of the four support steel columns installed with the load force test strain gauge is placed on the marked position on the table of the stamping machine to be tested; Install a hydraulic cylinder on each supporting steel column and use a level to calibrate the position of the hydraulic cylinder to ensure that each hydraulic cylinder is in a horizontal state; After assembling the test bracket, place it on the table of the stamping machine to be tested, and place multiple annular pads between the first support beam and the table of the stamping machine to be tested to adjust the height of the test bracket, thereby ensuring that the test bracket is in a horizontal state relative to the reference point on the table of the stamping machine to be tested; then, the test bracket and the table of the stamping machine to be tested are relatively fixed by bolts to prevent the test bracket from being displaced during the pressure test; Installing a plurality of displacement sensors at positions corresponding to the second support beam and the support steel column respectively but not locking them; Pre-pressurize the displacement sensor to keep the base initial voltage value at 4-6V to ensure that the displacement sensor is within the working range; Use a square to observe whether the current displacement sensor is perpendicular to the table of the stamping machine to be tested; If the current displacement sensor is not perpendicular to the table of the stamping machine to be detected, the current displacement sensor is fine-tuned until the current displacement sensor is perpendicular to the table of the stamping machine to be detected, and the displacement sensor is locked and fixed; Use a protractor to observe in turn whether other displacement sensors are perpendicular to the table of the stamping machine to be tested, and lock and fix them after ensuring that each displacement sensor is perpendicular to the table of the stamping machine to be tested.

Images