A method and system for measuring static load deformation of a closed press

Abstract

The present application belongs to the technical field of press performance detection, and particularly relates to a closed press static load deformation measurement method and system. The method first standardizes the adjustment of the press state and arranges the loading and measurement components, arranges multiple hydraulic loaders on the workbench according to a rule, and installs high-precision indicating tables at the four corners of the slider and specific positions. Then, five-stage segmented loading is performed, and the deformation data of each measuring point are recorded synchronously. Finally, the overall rigidity, left-right deflection of the slider and left-right deflection of the workbench are calculated based on the obtained data. Through the standardized loading arrangement rule, multi-measuring-point synchronous data acquisition and staged loading process, the present application effectively improves the accuracy, consistency and repeatability of the static load deformation measurement of the press, and can accurately evaluate the overall rigidity of the press and the bending resistance of the key components.

Description

Technical Field

[0001] This invention belongs to the field of press performance testing technology, specifically relating to a method and system for measuring static deformation of a closed press. Background Technology

[0002] As equipment in the equipment manufacturing industry, presses are used for processes such as sheet metal stamping, forming, and forging.

[0003] In press stiffness measurement tests, the hydraulic loaders are placed roughly on the worktable, with varying front-to-back spacing, left-to-right spacing, and distances between the loaders and the table edge. This irregular arrangement causes the resultant load point to deviate from the geometric center of the table, generating an additional overturning moment. The columns bear extra tension and compression, and the overall machine stiffness measurement values ​​fluctuate with the arrangement. Furthermore, the measurement results for different batches of the same equipment exhibit significant dispersion, making it difficult to meet requirements.

[0004] The method for measuring slider deflection involves densely arranging indicator tables on the bottom surface. The number, location, and spacing of measuring points vary, and different operators select different spans of measuring points. Some divide the deformation difference by the local spacing, while others divide by the entire length of the base plate. This results in chaotic dimensional processing and makes the measured data incomparable laterally. Summary of the Invention

[0005] This invention provides a method for measuring the static deformation of a closed press. Through standardized loading and precise measurement point positioning, it enables accurate detection of the overall machine stiffness, slider and worktable deflection, thereby improving measurement consistency and accuracy.

[0006] The methods include: S1: Adjust the mold loading height of the closed press to the middle position, so that the slide stops at the bottom dead center, and adjust the balancer air pressure to the working air pressure; at the same time, prepare multiple hydraulic loaders of the same specifications and multiple high-precision indicators; S2: The hydraulic loaders are evenly distributed within two-thirds of the length and width of the worktable surface, in two equal rows, with the center of the loader placed at the center of the equally divided area. S3: Install the first, second, third, and fourth indicators on the upper crossbeam of the measuring platform, with the probes of each indicator vertically upward contacting the four corner areas of the lower end face of the slider base plate; install the fifth indicator on the upper crossbeam of the measuring platform, with the probe vertically upward contacting the center area of ​​the lower end face of the slider base plate, and located in the middle of the line connecting the first and second indicators; install the sixth indicator on the lower crossbeam of the measuring platform, with the probe vertically downward contacting the center area of ​​the upper end face of the moving worktable. S4: The hydraulic loader is used to load the press worktable in segments. The load starts from zero and increases in stages according to one-fifth, two-fifths, three-fifths, four-fifths and five-fifths of the nominal force. After each loading, the readings of the first indicator, the second indicator, the third indicator, the fourth indicator, the fifth indicator and the sixth indicator are recorded. S5: Calculate the arithmetic mean of the readings of the first, second, third, and fourth indicators under each load level, and use it as the average relative deformation of the press under that load level. S6: Based on the readings of the first, second, and fifth indicators under the nominal force load, and the span between the measuring points of the first and second indicators, calculate the left and right deflection of the bottom surface of the slider under the uniformly distributed load. S7: Calculate the left and right deflections of the workbench under uniform load based on the reading of the sixth indicator under the nominal load and the center distance between the left and right support legs.

[0007] According to another embodiment of this application, a closed press static load deformation measurement system is provided, the system comprising: a press body, a hydraulic loading assembly, a displacement measuring assembly, and a measuring table; The press body includes: a body, a slide block, a worktable, and a movable worktable; the lower end of the slide block has a horizontal slide block base plate, the worktable is located below the slide block, and the movable worktable is positioned above the worktable. The hydraulic loading assembly includes: multiple hydraulic loaders of the same specifications; The displacement measurement assembly includes: a first indicator, a second indicator, a third indicator, a fourth indicator, a fifth indicator, and a sixth indicator; The measuring stand is placed independently on the press base or the ground, without contacting the worktable or the press body; the measuring stand includes four columns, an upper crossbeam and a lower crossbeam; the four columns are erected on the outside of the moving worktable, the upper crossbeam is fixedly connected to the four columns and located below the slider base plate, and the lower crossbeam is fixedly connected to the four columns and located above the moving worktable. The first indicator, the second indicator, the third indicator, and the fourth indicator are installed on the upper crossbeam, and the probes of each indicator are vertically upward in contact with the four corner areas of the lower end face of the slider base plate. The fifth indicator is installed on the upper crossbeam, with its probe vertically upward contacting the center area of ​​the lower end face of the slider base plate, and located in the middle of the line connecting the first and second indicators; the sixth indicator is installed on the lower crossbeam, with its probe vertically downward contacting the center area of ​​the upper end face of the movable worktable.

[0008] As can be seen from the above technical solutions, the present invention has the following advantages: The loader of this invention is arranged in two equally spaced rows within two-thirds of the length and width of the platform, with the center falling at the center of the equally spaced area. The geometric relationship of the load distribution is uniquely determined, and different operators can reproduce the same loading pattern, eliminating measurement dispersion caused by arbitrary arrangement. The four corner indicators are arranged at a preset distance from the edge of the slider base plate. The four points are symmetrical about the geometric center. After arithmetic averaging, the rigid body rotation components are automatically canceled out, while vertical translational deformation is retained. The overall machine stiffness is calculated using the average relative deformation, resulting in stable results. The measuring platform is arranged independently of the press frame columns. The four columns stand on the outside of the platform. The upper crossbeam carries the slider center indicator, and the lower crossbeam carries the platform center indicator, forming an external measurement reference chain. The absolute sinking of the slider, the absolute sinking of the platform, and the relative displacement of the two can be read separately. The overall machine stiffness and component deflection data are naturally decoupled, and the elastic deformation of the machine body is no longer coupled into the readings. The slider deflection measurement only takes three points on the transverse axis of symmetry. The curvature is obtained by dividing the difference between the average sinking at the edge and the sinking at the center by the span of the measuring point, and then extrapolating to the entire plate length. This replaces the dense distribution of points on the bottom surface. The collinear arrangement of the three points makes the left and right deflection calculation benchmarks unified as the transverse axis of symmetry, and the dimension processing is consistent.

[0009] Five equal loading levels were applied, with samples taken segment by segment from zero to the nominal force. Five data pairs were obtained from the load-deformation curve. The secant stiffness could be calculated by the difference between adjacent levels, and the slope of the elastic segment could be calculated by the overall fitting. The stiffness evaluation was expanded from a single point to multiple segments, and the boundary between the gap compaction segment and the elastic linear segment was clearly distinguishable on the curve.

[0010] The deflection of the worktable is measured by the distance between the centers of the left and right legs of the frame. The deflection is obtained directly by the ratio of the reading of the center indicator of the table to the span. The frame columns stand on the outside of the table and do not bear the loading reaction force. The reference settlement can be ignored. The bending deformation of the table can be measured independently. The deformation of the base frame is no longer used to artificially inflate the deflection value. Attached Figure Description

[0011] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0012] Figure 1 Schematic diagram of a closed-type press static load deformation measurement system; Figure 2 This is a schematic diagram of the displacement measurement component; Figure 3 A schematic diagram of the loader layout; Figure 4 This is a graph showing the overall machine stiffness. Figure 5 This is a schematic diagram of the overall machine stiffness curve.

[0013] Explanation of reference numerals in the attached figures: P1-First indicator, P2-Second indicator, P3-Third indicator, P4-Fourth indicator, P5-Fifth indicator, P6-Sixth indicator, 1-Measuring stand, 2-Slider, 3-Slider base plate, 4-Moving worktable, 5-Hydraulic loader, 6-Worktable surface, 7-Pressure body, 8-Upper crossbeam, 9-Lower crossbeam. Detailed Implementation

[0014] Combination Figures 1 to 3 As shown, the closed-type press static load deformation measurement system includes a press body 7, a hydraulic loading assembly, a displacement measurement assembly, and a measuring table 1.

[0015] The press body 7 includes a body, a slider 2, a worktable 6, and a movable worktable 4. The slider 2 has a horizontal slider base plate 3 at its lower end, the worktable 6 is located below the slider, and the movable worktable 4 is positioned above the worktable 6.

[0016] The hydraulic loading assembly includes multiple hydraulic loaders 5 of the same specifications. Each hydraulic loader 5 is arranged on the upper surface of the worktable 6, and is distributed in two equal rows along the preset loading range in the length and width directions of the worktable 6.

[0017] Specifically, the preset loading range is divided equally along the length direction according to the number of loaders in each row, and equally along the width direction according to the front and rear rows, forming multiple sub-regions with equal area. The geometric center of each sub-region is the geometric center of the corresponding hydraulic loader 5.

[0018] Taking 6 loaders as an example: Preset loading range length L x =3000mm, width W y =2000mm; two rows, front and back, three in each row. The length is divided into three equal segments, each 1000mm; the width is divided into two equal segments, each 1000mm; resulting in 3 columns × 2 rows, a total of 6 sub-regions of 1000mm × 1000mm; the center point of each sub-region is the placement point of the hydraulic loader 5. When there are four loaders, a lower pad is added between the hydraulic loader 5 and the worktable 6, and an upper pad is added between the hydraulic loader 5 and the slider base plate 3 to expand the load transfer area.

[0019] The displacement measurement assembly includes a first indicator P1, a second indicator P2, a third indicator P3, a fourth indicator P4, a fifth indicator P5, and a sixth indicator P6.

[0020] The measuring stand 1 is placed independently on the press base or the ground, without contacting the worktable 6 or the press body. The measuring stand 1 includes four columns, an upper crossbeam 8, and a lower crossbeam 9. The four columns are erected on the outside of the movable worktable 4, the upper crossbeam 8 is fixedly connected to the four columns and located below the slider base plate 3, and the lower crossbeam 9 is fixedly connected to the four columns and located above the movable worktable 4.

[0021] The first indicator P1, the second indicator P2, the third indicator P3, and the fourth indicator P4 are mounted on the upper crossbeam 8, with the probes of each indicator vertically upward contacting the four corner areas of the lower end face of the slider base plate 3, 150mm from the edge of the slider base plate 3. The fifth indicator P5 is mounted on the upper crossbeam 8, with its probe vertically upward contacting the center area of ​​the lower end face of the slider base plate 3, and located at the midpoint of the line connecting the first indicator P1 and the second indicator P2. The sixth indicator P6 is mounted on the lower crossbeam 9, with its probe vertically downward contacting the center area of ​​the upper end face of the movable worktable 4.

[0022] It should be noted that the four columns of the measuring stand 1 are independently positioned relative to the worktable 6, making the measuring stand 1 a self-contained frame, independent of the press columns or crossbeams, thus isolating the influence of the machine body's elastic deformation on the reference values ​​of the fifth and sixth indicators. The installation relationship between the upper crossbeam 8 and the fifth indicator is such that the fifth indicator is positioned directly below the center of the slider base plate 3, with the probe touching the lower end face of the slider base plate 3 upwards to directly obtain the slider center sinking amount. The installation relationship between the lower crossbeam 9 and the sixth indicator is such that the sixth indicator is positioned directly above the center of the upper end face of the moving worktable 4, with the probe touching the upper end face of the moving worktable 4 downwards to directly obtain the moving worktable 4 center sinking amount. The vertically opposite arrangement of the fifth and sixth indicators on the measuring stand 1 forms a direct measurement chain for the relative displacement between the lower end face of the slider base plate 3 and the upper end face of the moving worktable. The reading of the fifth indicator reflects the absolute displacement of the slider base plate 3, and the reading of the sixth indicator reflects the absolute displacement of the moving worktable 4; the difference between the two is the overall machine elastic deformation.

[0023] Optionally, when the number of hydraulic loaders is small, such as four, a lower pad is sandwiched between the hydraulic loader and the worktable, and an upper pad is sandwiched between the hydraulic loader and the slider base plate. The clamping relationship between the pads and the hydraulic loaders, the worktable, and the slider base plate increases the bearing area, reduces contact stress concentration, and makes the loader's output force more evenly distributed between the slider base plate and the worktable, reducing the interference of local indentation on deformation measurement.

[0024] The measurement process of the system of this invention involves applying a load to the slider base plate using a hydraulic loader. The load is increased progressively from zero in increments of one-fifth, two-fifths, three-fifths, four-fifths, and five-fifths of the nominal force. After each load level stabilizes, the readings of all indicators are recorded. The readings of the first to fourth indicators are used to calculate the overall machine stiffness. The readings of the first, second, and fifth indicators are used to calculate the lateral deflection of the slider; the reading of the sixth indicator is used to calculate the lateral deflection of the moving worktable.

[0025] In this embodiment, the measuring stand is independent of the press body to avoid interference from the measuring reference caused by the deformation of the press body; the probe contacts the lower end face of the slider base plate upward to directly obtain the slider displacement; the probe contacts the upper end face of the moving worktable downward to directly obtain the worktable displacement; the fifth and sixth indicators arranged vertically form a direct measuring chain, and the difference is the elastic deformation of the whole machine.

[0026] The static deformation measurement method for a closed-type press according to this application will be described in detail below. Specific details such as particular system structures and technologies are presented for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application can also be implemented in other embodiments without these specific details.

[0027] It should be understood that, when used in this specification, the term "comprising" indicates the presence of the described feature, integral, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0028] To facilitate a clear description of the technical solutions of this application, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, nor do they necessarily imply that they are different.

[0029] The terms "one embodiment" or "some embodiments" used in this application mean that one or more embodiments of this application include the specific features, structures, or characteristics described in that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this application do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Please see Figure 1 The diagram shows a flowchart of a method for measuring the static deformation of a closed-type press in a specific embodiment. The method includes: S1: Adjust the mold loading height of the closed press to the middle position, so that the slide stops at the bottom dead center, and adjust the balancer air pressure to the working air pressure; at the same time, prepare multiple hydraulic loaders of the same specifications and multiple high-precision indicators.

[0032] In some embodiments, the die mounting height of the closed press is adjusted to the intermediate position. The die mounting height is the vertical distance between the bottom surface of the slide and the upper surface of the table plate when the slide is at its bottom dead center, and the intermediate position refers to 50% of the distance adjustment stroke.

[0033] An optional operating method is as follows: Loosen the mechanical locking device of the mold height adjustment mechanism, start the mold adjustment motor to drive the worm gear pair, causing the connecting rod length to change. Observe the mold adjustment indicator pointer reaching the middle scale, then stop the motor and relock. Stop the slider at the bottom dead center. The bottom dead center is the lowest limit position of the slider stroke, located by a crankshaft angle encoder or mechanical stop. Jog the main motor to the bottom dead center and then cut off the power to keep the slider stationary. Adjust the balancer air pressure to the working air pressure.

[0034] The balancer is a pneumatic or hydraulic balancing device that counteracts the weight of the slider and upper die. The working air pressure is the rated balancing pressure value specified on the equipment nameplate. The output pressure of the air tank or accumulator is adjusted to this rated value through the pressure regulating valve. After observing that the pressure gauge pointer is stable, the pressure regulating valve is locked. Prepare multiple hydraulic loaders of the same specifications.

[0035] The hydraulic loader is a single-acting or double-acting hydraulic cylinder with a rated working pressure not lower than the maximum oil pressure required for the test and a stroke not less than the maximum compression required for the test. Multiple high-precision indicators are prepared. These indicators are mechanical dial indicators or electronic digital dial indicators, with a range covering the estimated maximum deformation.

[0036] S2: The hydraulic loaders are evenly distributed within two-thirds of the length and width of the worktable, in two equal rows, with the center of the loader placed at the center of the equally divided area.

[0037] In some specific embodiments, the process of evenly distributing the hydraulic loaders within two-thirds of the length and width of the worktable includes the following steps: S211: Get the length L and width W of the workbench.

[0038] The worktable here is a rectangular plane. The length L refers to the dimension in the direction of slider movement, and the width W refers to the dimension perpendicular to the direction of slider movement.

[0039] S212: Determine if L is greater than 5000 mm. If L ≤ 5000 mm, calculate the length L of the arrangement area of ​​the hydraulic loader in the length direction of the worktable. x =(2 / 3)×L, if L>5000 then calculate L. x =(4 / 5)×L; Calculate the left boundary L of the loading interval in the length direction. eft =(LL x ) / 2, right boundary R ight =(L+L x ) / 2.

[0040] It should be noted that the longer the press table, the greater the relative proportion of the load distribution area that needs to be covered can be, from 2 / 3 to 4 / 5, to simulate the stress concentration area of ​​a large-table press during actual stamping. eft and R ight The calculation ensures that the center of the loading interval coincides with the center of the platform along its length, thus avoiding off-center loading.

[0041] S213: Width W of the area where the hydraulic loader is arranged in the width direction of the press worktable. y The calculation method is as follows: when L≤5000, W y =(2 / 3)×W; when L>5000, W y =(4 / 5)×W. Calculate the front boundary F of the loading interval in the width direction. ront =(WW y ) / 2, rear boundary R ear =(W+W y ) / 2; Place the bottom geometric center point of each hydraulic loader at the length coordinate ∈ [L eft ,R ight ], and the width coordinate ∈ [F ront ,R ear Within the rectangular area of ​​].

[0042] In this way, the principle of symmetrical centering is adopted in the width direction, so that the loading area covers two-thirds or four-fifths of the middle area of ​​the table surface, avoiding the edge stress change zone.

[0043] In some specific embodiments, the steps of distributing the loaders in two equal rows with the center of the loader located at the center of the equally divided area include: S221: Determine the total number N of hydraulic loaders, and determine that N is an even number; divide the N loaders into front and rear rows, with each row containing N / 2 loaders.

[0044] It should be noted that the N value is read based on the actual number of hydraulic loaders. If N is odd, add one loader or adjust the loader specifications to make N an even number. The front row refers to the side closest to the press operator, and the back row refers to the side furthest from the operator. Place N / 2 loaders in the front row and N / 2 loaders in the back row. An even number ensures that the number of loaders in each row is equal, resulting in the same total load generated by the front and back rows and preventing overturning moments.

[0045] S222: Calculate the spacing D between the centerlines of the front and rear rows of loaders, D=(2 / 3)×W y Set the width coordinate of the center line of the front loader to F. ront +D / 2, Width coordinate of the rear loader centerline = R ear -D / 2.

[0046] It should be noted that the spacing between the front and rear rows is designed to be two-thirds of the width of the loading area, so that the loading point is located symmetrically in the width direction of the worktable, simulating the point of application of the resultant force of a uniformly distributed load. The coordinates of the front and rear rows are symmetrical about the centerline in the width direction.

[0047] S223: For the front row, calculate the equally spaced intervals a=L along the length direction. x / (N / 2); Set the center length coordinate of the first loader in the front row to L. eft +a / 2, subsequent loaders are incremented by 'a'; for the back row, the same 'a' value is used, and the center length coordinate of the first loader in the back row is set to L. eft +a / 2, subsequent loaders are incremented by 'a'; this ensures that the center point of all loaders is located on a grid point determined by both the length and width coordinates.

[0048] It should be noted that when N / 2 = 1, a = L x The first and only loader center length coordinate = L eft +L x / 2, which is the midpoint of the loading interval.

[0049] When N / 2≥2, a=L x / (N / 2). The center distance of the first loader in the front row from the left boundary is a / 2, and the center distance of each subsequent loader is a. The same applies to the back rows. The set of length coordinates of the loader center points is {L}. eft +(k-0.5)×a | k=1,2,...,N / 2}, the width coordinates of the first row are fixed as F. ront +D / 2, rear row fixed as R ear -D / 2.

[0050] It can be seen that the equidistant arrangement ensures that the loaders are evenly distributed along the length, avoiding local load concentration. Placing the first loader at half a distance from the boundary ensures that the distance from both the first and last loaders to the boundary of the loading area is a / 2, achieving symmetry at both ends. This arrangement ensures that the resultant force of the loaders is located exactly at the geometric center of the loading interval, i.e., the center of the equally divided area.

[0051] S3: Install the first indicator P1, the second indicator P2, the third indicator P3, and the fourth indicator P4 on the upper crossbeam of the measuring platform, with the probes of each indicator vertically upward contacting the four corner areas of the lower end face of the slider base plate; install the fifth indicator P5 on the upper crossbeam of the measuring platform, with the probe vertically upward contacting the center area of ​​the lower end face of the slider base plate, and located in the middle of the line connecting the first indicator P1 and the second indicator P2; install the sixth indicator P6 on the lower crossbeam of the measuring platform, with the probe vertically downward contacting the center area of ​​the upper end face of the moving worktable.

[0052] S4: The hydraulic loader is used to apply segmented loads to the press worktable. The load is increased step by step from zero to one-fifth, two-fifths, three-fifths, four-fifths, and five-fifths of the nominal force. After each loading, the readings of the first indicator P1, the second indicator P2, the third indicator P3, the fourth indicator P4, the fifth indicator P5, and the sixth indicator P6 are recorded.

[0053] In some specific embodiments, step S4 specifically includes the following steps: S41: Determine the value of the nominal force Fn, and calculate the five load level values ​​of one-fifth, two-fifths, three-fifths, four-fifths, and five-fifths, respectively denoted as F1, F2, F3, F4, and F5.

[0054] It should be noted that the nominal force value should be read from the nameplate or technical parameter table of the press. Set F1=Fn / 5, F2=2×Fn / 5, F3=3×Fn / 5, F4=4×Fn / 5, F5=Fn.

[0055] S42: Start the hydraulic loader to increase the output load, reaching F1, F2, F3, F4, and F5 in sequence; after each load level is reached, maintain the load fluctuation within ±1% for a preset duration.

[0056] The slow loading here prevents elastic vibration caused by impact loads, allowing the press structure to enter a quasi-static deformation state.

[0057] S43: During the maintenance time of each load level, read the dial values ​​of the first to sixth indicator tables in sequence, and fill the reading of each table into the corresponding cell of the data recording table according to the load level.

[0058] S5: Calculate the arithmetic mean of the readings of the first indicator P1, the second indicator P2, the third indicator P3, and the fourth indicator P4 under each load level, and use it as the average relative deformation of the press under that load level.

[0059] In some specific embodiments, S5 specifically includes the following steps: S51: Extract four sets of readings from the first indicator P1, the second indicator P2, the third indicator P3, and the fourth indicator P4 under the same load level. Add the four values ​​together and divide by four to obtain the readings and average values ​​under that load level.

[0060] S52: Repeat the above summation and division operations for the five load levels in sequence to obtain five average values. Each average value corresponds to the average relative deformation of the press in the working direction under a load level.

[0061] It should be noted that the four indicators are located at the four corners of the bottom surface of the slider, corresponding to the positions of the four columns of the press body. When the press bears a vertical load, the slider undergoes overall vertical displacement, but the displacement at the four corners may vary slightly due to asymmetry of the press body, off-center loading, or manufacturing errors. Taking the arithmetic mean can eliminate the deviation caused by the difference in the four corner displacements, obtaining the overall average sinking of the slider, which represents the comprehensive elastic deformation in the working direction of the press. In step S52, the load level number i is set to 1, 2, 3, 4, 5, corresponding to the load value Fi = i × Fn / 5. For each i, step S51 is executed: read the readings of the first indicator P1, the second indicator P2, the third indicator P3, and the fourth indicator P4 under that load level, and record them as a. 1i a 2i a 3i a 4i Calculate S i =a 1i +a 2i +a 3i +a 4i Calculate P avgi =S i / 4. The average deformation P under the first level of load. avg1 The average deformation P under the second level load avg2 The average deformation P under the third level of load avg3 The average deformation P under the fourth level load avg4 The average deformation P under the fifth level load avg5 Fill in the rows corresponding to the average value column of the calculation indicator table in the data record table in sequence.

[0062] This invention takes into account that the elastic deformation of a press increases approximately linearly with increasing load, but the actual curve may exhibit slight nonlinearity. By obtaining the average deformation at five different load levels, a load-deformation curve can be plotted to verify linearity, calculate stiffness, or identify outliers. The five points cover the entire process from no-load to full-load, meeting the sampling requirements for stiffness calculation.

[0063] S6: Based on the readings of the first indicator P1, the second indicator P2, and the fifth indicator P5 under the nominal force load, as well as the span between the measuring points of the first indicator P1 and the second indicator P2, calculate the left and right deflection of the bottom surface of the slider under the uniformly distributed load.

[0064] In some specific embodiments, S6 specifically includes the following steps: S61 retrieves the readings of the first indicator P1, the second indicator P2, and the fifth indicator P5 under the nominal force load recorded in S4, and subtracts the initial readings of each indicator under zero load to obtain the absolute deformation ΔP1 of the first indicator P1, the absolute deformation ΔP2 of the second indicator P2, and the absolute deformation ΔP5 of the fifth indicator P5. A steel tape measure is used to measure the straight-line distance between the center of the probe of the first indicator P1 and the center of the probe of the second indicator P2 on the transverse axis of symmetry of the bottom surface of the slider, which is recorded as the measuring point span L12.

[0065] S62 sums ΔP1 and ΔP2 obtained in S61 and divides by two to obtain the average deformation ΔP12 between the first indicator P1 and the second indicator P2; calculates the difference ΔP12 and ΔP5, Δf = ΔP12 - ΔP5; divides the difference Δf by the span L12 of the measuring point to obtain the deformation difference ratio per unit span of the slider bottom surface; multiplies the deformation difference ratio by the length of the slider bottom plate to obtain the left and right deflection of the slider bottom surface under uniform load.

[0066] It should be noted that the readings of the first indicator P1, the second indicator P2, and the fifth indicator P5 under the nominal force load condition are recorded as v1F, v2F, and v5F, respectively. Here, the first indicator P1 and the second indicator P2 are arranged symmetrically on the left and right sides of the bottom surface of the slider, and the fifth indicator P5 is arranged at the transverse center of the bottom surface of the slider. These three indicators form a three-point symmetrical measurement line on the transverse axis of symmetry. The readings of the first indicator P1 and the second indicator P2 reflect the sinking of the left and right edges of the slider, while the reading of the fifth indicator P5 reflects the sinking of the center of the slider.

[0067] Extract the initial readings of the three indicators under zero load conditions, and record them as v10, v20, and v50, respectively. Calculate the absolute deformation of the first indicator P1 measuring point using the formula ΔP1=v1F-v10, the second indicator P2 measuring point using the formula ΔP2=v2F-v20, and the fifth indicator P5 measuring point using the formula ΔP5=v5F-v50. Align the zero point of the steel tape measure with the center of the first indicator P1 probe, straighten the steel tape measure to the center of the second indicator P2 probe, and read the straight-line distance between the centers of the two probes on the transverse axis of symmetry of the bottom surface of the slider, recording it as the measuring point span L12. The measuring point span L12 is the center distance between the probes of the first indicator P1 and the second indicator P2, representing the horizontal reference length between the left and right measuring points. The absolute deformation is obtained by subtracting the zero-position reading from the loaded reading, eliminating the influence of the initial installation reference and the zero position of the instrument.

[0068] For S62, retrieve ΔP1, ΔP2, ΔP5, and L12 obtained from S61; calculate the average deformation between the first indicator P1 and the second indicator P2 using the formula ΔP12=(ΔP1+ΔP2) / 2. Calculate the difference between the average subsidence of the left and right edges and the subsidence of the center using the formula Δf=ΔP12-ΔP5; and calculate the difference using the formula δ... 滑 =Δf / L12×L to calculate the left and right deflection of the slider, where δ 滑 Let ΔP12, ΔP5, L12, and L be the left and right deflections of the slider. Substitute ΔP12, ΔP5, L12, and L into the above formula and calculate the left and right deflection values ​​of the slider successively.

[0069] Here, three local measurements replace the dense measurement points on the entire plate, reducing the number of indicator gauges. The curvature extrapolation method extends the results of the local three-point measurements to the left and right deflection of the entire plate, avoiding the need to arrange too many measurement points on the bottom surface of the slider.

[0070] S7: Calculate the left and right deflections of the workbench under uniform load based on the reading of the sixth indicator P6 under nominal load and the center distance between the left and right support legs.

[0071] In some specific embodiments, S7 specifically includes the following steps: S71 retrieves the reading of the sixth indicator P6 under nominal load and the initial reading of the sixth indicator P6 under zero load recorded by S4. The absolute deformation of the sixth indicator P6 measuring point is obtained by subtracting the initial reading from the nominal load reading. A steel tape measure is used to measure the straight-line distance on the horizontal axis of symmetry between the center of the bottom surface of the left and right legs of the measuring platform, which is recorded as the distance between the center of the left and right legs of the platform, L6.

[0072] S72 divides the absolute deformation of the sixth indicator P6 measuring point obtained from S71 by the center distance L6 between the left and right platform legs to obtain the left and right deflection of the workbench plate under uniform load.

[0073] It should be noted that the reading v6F of the sixth indicator P6 under nominal load and the initial reading v60 of the sixth indicator P6 under zero load are extracted from the S4 data record. The absolute deformation of the sixth indicator P6 measuring point is calculated using the formula ΔP6=v6F-v60. The reading of the sixth indicator P6 reflects the downward displacement of the worktable surface relative to the reference of the measuring platform. The initial reading v60 under zero load records the initial reference displacement caused by the self-weight of the measuring platform and the installation gap, and the nominal load reading v6F records the total downward displacement of the worktable surface after loading. Subtracting the two eliminates the influence of the initial reference, obtaining the absolute downward displacement ΔP6 of the worktable surface caused purely by the uniformly distributed load. The center distance L6 between the left and right supports of the measuring platform is the horizontal span between the measuring point of the sixth indicator P6 and the two side support points, constituting the horizontal reference length for calculating the left and right deflection of the worktable.

[0074] Based on the absolute deformation ΔP6 of the sixth indicator P6 measuring point and the center distance L6 between the left and right support legs obtained from S71, the sixth indicator P6 measuring point is located directly below the transverse center of the measuring platform. Under a uniformly distributed load, the worktable undergoes symmetrical bending, and the sixth indicator P6 is at the mid-span position. The absolute settlement ΔP6 is the mid-span deflection value. The center distance L6 between the left and right support legs is the support span. The ratio of the mid-span deflection to the span directly reflects the degree of transverse bending of the worktable. Formula δ 台 =ΔP6 / L6 normalizes the vertical displacement at mid-span to a deflection ratio relative to the support span, expressing the horizontal bending deformation of the worktable in the left-right direction. The result is directly calculated from measured data, avoiding the transmission of errors from multiple measurement points.

[0075] In one embodiment of the present invention, based on the static deformation measurement method of a closed press, the following will provide a possible embodiment and describe its specific implementation in a non-limiting manner.

[0076] The method for measuring the static deformation of a closed press according to the present invention includes three parts: overall machine stiffness measurement, slider deflection measurement, and worktable deflection measurement.

[0077] Overall machine stiffness is calculated by dividing the nominal force by the average relative deformation between the worktable and the slider at a given position when a uniformly distributed nominal force is applied over a specified range on the worktable surface. Slider deflection is the ratio of the deformation of the slider bottom surface measured to the span of its measuring point when a uniformly distributed nominal force is applied over a specified range on the worktable surface. Worktable deflection is the ratio of the deformation of the worktable plate to the span of its measuring point when a uniformly distributed nominal force is applied over a specified range on the worktable surface.

[0078] The test conditions of this invention are defined as follows: the mold height is adjusted to the middle position; the slider stops at the bottom dead center; and the balancer air pressure is the working air pressure.

[0079] A first indicator P1, a second indicator P2, a third indicator P3, a fourth indicator P4, and a fifth indicator P5 are installed 150mm (X1, Y1) from the edge of the slider base plate. These five indicators are positioned above the test frame, with their contacts on the bottom surface of the slider, to measure the deformation at the corresponding positions on the slider's worktable. A sixth indicator P6 is placed below the center of the test frame, with its contacts on the top surface of the moving worktable, to measure the relative deformation of the moving worktable at the corresponding position. If the slider base plate has a T-slot or hole, the X1 and Y1 positions should be adjusted appropriately to avoid the slot or hole.

[0080] The hydraulic loaders are, in principle, evenly distributed along the length L of the worktable. x and width W y Within the specified range, where conditions permit, multiple loaders should be deployed to ensure the load is distributed as evenly as possible. The loaders should be of identical specifications and arranged in two rows, with their centers positioned at the center of the equally divided area. The distance between their centers is specified as 2 / 3W. y The left and right spacing 'a' is determined according to the number of loaders based on the principle of equal division, see Appendix. Figure 3 For single-unit and line presses with a worktable length L less than or equal to 5000mm: L x =2 / 3×L, W y =2 / 3×W; For presses with a table length greater than 5000mm, such as multi-station presses, the general formula is: L x =4 / 5×L, W y =4 / 5×W.

[0081] Apply load to the press and use gauges to measure the deformation at the corresponding locations. Start with zero and gradually increase the load, incrementing in steps of Fn / n. Record the gauge readings after each load increase, continuing until 100% nominal force is reached. Record the readings of gauges P1, P2, P3, and P4 in segments, and calculate the average value for each segment. Table 1 shows the overall machine stiffness test data.

[0082] Table 1. Record of overall machine stiffness test data

[0083] Table 2 shows the record of deflection test data for the slider and the moving worktable.

[0084] Table 2. Data Recording of Deflection Tests on Slider and Moving Worktable

[0085] For the calculation of the overall machine stiffness, the overall machine stiffness is calculated according to formula (1), and the overall machine stiffness curve is shown in the appendix. Figure 4 As shown.

[0086] = = (1) In the formula: —Overall machine rigidity; —The elastic deformation of the press in the working direction when the test load reaches the nominal force; —The increase in loading force for each test; —The difference between the average values ​​of the four tables corresponding to each test loading, which is the amount of elastic deformation in the working direction of the press.

[0087] The left and right deflection of the slider can be calculated using formula (2): = (2) In the formula: The left and right deflection of the slider; , , These are the readings of the first indicator P1, the fifth indicator P5, and the second indicator P2, respectively. L1 represents the measured distance between the first indicator P1 and the second indicator P2. .

[0088] The lateral deflection of the movable worktable is calculated according to formula (3): =(Δ2 / L2)(3) In the formula: The left and right deflection of the worktable; The left and right deflection of the workbench is read from the sixth indicator P6; L2 is the distance between the centers of the left and right support legs.

[0089] It can be seen that standardized loading and measurement point layout eliminate human error and improve measurement repeatability and consistency. Segmented loading and multi-point data acquisition ensure that the data closely reflects actual working conditions. The system completes the testing of overall machine stiffness, slider deflection, and moving table deflection in a single operation, improving testing efficiency. The calculation formulas can directly output stiffness and deflection, facilitating equipment performance evaluation.

[0090] The following is a specific implementation example: A closed-type two-point press was selected, with a nominal force of It is equipped with 6 hydraulic loaders of the same specifications.

[0091] The loaders are arranged in two rows, each covering two-thirds of the length and width, respectively. For overall machine stiffness testing: First indicator P1, second indicator P2, third indicator P3, and fourth indicator P4 are installed 150mm from the four corners of the slider. For deflection testing: A mounting frame, fifth indicator P5, and sixth indicator P6 are installed, aligned with the measuring points. The mold height is adjusted to the center position, the slider to the bottom dead center, and the balancer to the working air pressure. Loading is applied in five segments, and the indicator readings are recorded segment by segment. The overall machine stiffness, slider lateral deflection, and worktable lateral deflection are calculated. A standard recording table is used to record the applied force, the readings of each indicator, the average value, and the calculation results. The overall machine stiffness data recording table is shown in Table 3, and the overall machine stiffness curve is shown in... Figure 5 As shown.

[0092] Table 3. Overall Machine Stiffness Data Recording Table

[0093] Based on the current deformation of the 10000KN full-tonnage machine (5.06-0.55=4.51mm), the overall stiffness is 2217kN / mm. The deformation measurement data for the slider and moving worktable are recorded in Table 4.

[0094] Table 4. Deformation Measurement Data Record of Moving Worktable

[0095] Left and right deflection of the slider: =

[0096] =

[0097] Lateral deflection of the moving worktable: =

[0098] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0099] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for measuring the static deformation of a closed-type press, characterized in that the method... include: S1: Adjust the mold loading height of the closed press to the middle position, so that the slide stops at the bottom dead center, and adjust the balancer air pressure to the working air pressure; at the same time, prepare multiple hydraulic loaders of the same specifications and multiple high-precision indicators; S2: The hydraulic loaders are evenly distributed within two-thirds of the length and width of the worktable surface, in two equal rows, with the center of the loader placed at the center of the equally divided area. S3: Install the first indicator (P1), the second indicator (P2), the third indicator (P3), and the fourth indicator (P4) on the upper crossbeam of the measuring platform, with the probes of each indicator vertically upward contacting the four corner areas of the lower end face of the slider base plate; install the fifth indicator (P5) on the upper crossbeam of the measuring platform, with the probe vertically upward contacting the center area of ​​the lower end face of the slider base plate, and located at the midpoint of the line connecting the first indicator (P1) and the second indicator (P2); install the sixth indicator (P6) on the lower crossbeam of the measuring platform, with the probe vertically downward contacting the center area of ​​the upper end face of the moving worktable; S4: The hydraulic loader is used to load the press worktable in segments. The load starts from zero and increases in stages according to one-fifth, two-fifths, three-fifths, four-fifths and five-fifths of the nominal force. After each loading, the readings of the first indicator (P1), the second indicator (P2), the third indicator (P3), the fourth indicator (P4), the fifth indicator (P5) and the sixth indicator (P6) are recorded. S5: Calculate the arithmetic mean of the readings of the first indicator (P1), the second indicator (P2), the third indicator (P3), and the fourth indicator (P4) under each load level, and use it as the average relative deformation of the press under that load level. S6: Based on the readings of the first indicator (P1), the second indicator (P2), and the fifth indicator (P5) under the nominal force load, and the span between the measuring points of the first indicator (P1) and the second indicator (P2), calculate the left and right deflection of the bottom surface of the slider under the uniformly distributed load. S7: Calculate the left and right deflection of the workbench under uniform load based on the reading of the sixth indicator (P6) under nominal load and the center distance between the left and right frame legs.

2. The method for measuring static deformation of a closed-type press according to claim 1, characterized in that, In S2, the process of evenly distributing the hydraulic loaders within two-thirds of the length and width of the worktable surface includes the following steps: Get the length L and width W of the worktable surface; Determine if L is greater than 5000 mm. If L ≤ 5000 mm, calculate the length L of the area where the hydraulic loader is arranged along the length of the worktable. x =(2 / 3)×L, if L>5000 then calculate L. x =(4 / 5)×L; Calculate the left boundary L of the loading interval in the length direction. eft =(LL x ) / 2, right boundary R ight =(L+L x ) / 2; The width W of the area where the hydraulic loader is arranged in the width direction of the press table. y The calculation method is as follows: when L≤5000, W y =(2 / 3)×W; when L>5000, W y =(4 / 5)×W; Calculate the front boundary F of the loading interval in the width direction. ront =(WW y ) / 2, rear boundary R ear =(W+W y ) / 2; Place the bottom geometric center point of each hydraulic loader at the length coordinate ∈ [L eft ,R ight ], and the width coordinate ∈ [F ront ,R ear Within the rectangular area of ​​].

3. The method for measuring static deformation of a closed-type press according to claim 2, characterized in that, In S2, the loaders are distributed equally in two rows, with the center of the loaders placed at the center of the equally divided area. The specific steps include: Determine the total number N of hydraulic loaders, and ensure that N is an even number; divide the N loaders into a front row and a rear row, with each row containing N / 2 loaders. Calculate the spacing D between the center lines of the two rows of loaders: D = (2 / 3) × W y Set the width coordinate of the center line of the front loader to F. ront +D / 2, Width coordinate of the rear loader centerline = R ear -D / 2; For the front row, calculate the equal intervals a=L along the length direction. x / (N / 2); Set the center length coordinate of the first loader in the front row to L. eft +a / 2, subsequent loaders are incremented by 'a'; for the back row, the same 'a' value is used, and the center length coordinate of the first loader in the back row is set to L. eft +a / 2, subsequent loaders are incremented by 'a'; this ensures that the center point of all loaders is located on a grid point determined by both the length and width coordinates.

4. The method for measuring static deformation of a closed-type press according to claim 1, characterized in that, S4 specifically includes the following steps: Determine the value of the nominal force Fn, and calculate the values ​​for five load levels: one-fifth, two-fifths, three-fifths, four-fifths, and five-fifths. Start the hydraulic loader to increase the output load, sequentially reaching five load levels: one-fifth, two-fifths, three-fifths, four-fifths, and five-fifths of the nominal force. After reaching each load level, maintain the load fluctuation within ±1% for a preset duration. During the maintenance time of each load level, the dial readings of the first to sixth indicator meters are read sequentially, and the readings of each meter are filled into the corresponding cells of the data recording table according to the load level.

5. The method for measuring static deformation of a closed-type press according to claim 1, characterized in that, S5 specifically includes the following steps: Extract four sets of readings from the first indicator (P1), the second indicator (P2), the third indicator (P3), and the fourth indicator (P4) under the same load level. Add the four values ​​together and divide by four to obtain the readings and average values ​​under that load level. Repeat the above summation and division operations for each of the five load levels to obtain five average values. Each average value corresponds to the average relative deformation of the press in the working direction under a load level.

6. The method for measuring static deformation of a closed-type press according to claim 1, characterized in that, S6 specifically includes the following steps: Retrieve the readings of the first indicator (P1), the second indicator (P2), and the fifth indicator (P5) under the nominal force load, and subtract the initial readings of each indicator under zero load to obtain the absolute deformation ΔP1 of the first indicator (P1), the absolute deformation ΔP2 of the second indicator (P2), and the absolute deformation ΔP5 of the fifth indicator (P5). Use a steel tape measure to measure the straight-line distance between the center of the probe of the first indicator (P1) and the center of the probe of the second indicator (P2) on the transverse axis of symmetry of the bottom surface of the slider, and record it as the span of the measuring point. Summing ΔP1 and ΔP2 obtained from S61 and dividing by two, we obtain the average deformation ΔP12 of the two points of the first indicator (P1) and the second indicator (P2); we calculate the difference ΔP12 and ΔP5, Δf = ΔP12 - ΔP5; we divide the difference Δf by the span of the measuring point to obtain the deformation difference ratio per unit span of the bottom surface of the slider; we multiply the deformation difference ratio by the length of the bottom plate of the slider to obtain the left and right deflection of the bottom surface of the slider under uniform load.

7. The method for measuring static deformation of a closed-type press according to claim 1, characterized in that, S7 specifically includes the following steps: Retrieve the reading of the sixth indicator (P6) under the nominal load and the initial reading of the sixth indicator (P6) under the zero load state recorded in S4. Subtract the initial reading from the nominal load reading to obtain the absolute deformation of the measuring point of the sixth indicator (P6). Use a steel tape measure to measure the straight distance between the center of the bottom surface of the left support and the center of the bottom surface of the right support on the horizontal axis of symmetry, and record it as the distance between the center of the left and right supports. Divide the absolute deformation of the sixth indicator (P6) obtained by S71 by the distance between the center of the left and right support legs to obtain the left and right deflection of the workbench under uniform load.

8. A closed-type press static load deformation measurement system, characterized in that, The system is used to implement the static deformation measurement method of a closed press as described in any one of claims 1 to 7; the system includes: a press body, a hydraulic loading assembly, a displacement measurement assembly, and a measuring table; The press body includes: a body, a slide block, a worktable, and a movable worktable; the lower end of the slide block has a horizontal slide block base plate, the worktable is located below the slide block, and the movable worktable is positioned above the worktable. The hydraulic loading assembly includes: multiple hydraulic loaders of the same specifications; The displacement measurement assembly includes: a first indicator (P1), a second indicator (P2), a third indicator (P3), a fourth indicator (P4), a fifth indicator (P5), and a sixth indicator (P6). The measuring stand is placed independently on the press base or the ground, without contacting the worktable or the press body; the measuring stand includes four columns, an upper crossbeam and a lower crossbeam; the four columns are erected on the outside of the moving worktable, the upper crossbeam is fixedly connected to the four columns and located below the slider base plate, and the lower crossbeam is fixedly connected to the four columns and located above the moving worktable. The first indicator (P1), the second indicator (P2), the third indicator (P3), and the fourth indicator (P4) are installed on the upper crossbeam, and the probes of each indicator are vertically upward in contact with the four corner areas of the lower end face of the slider base plate. The fifth indicator (P5) is installed on the upper crossbeam, with its probe vertically upward contacting the center area of ​​the lower end face of the slider base plate, and located in the middle of the line connecting the first indicator (P1) and the second indicator (P2); the sixth indicator (P6) is installed on the lower crossbeam, with its probe vertically downward contacting the center area of ​​the upper end face of the moving worktable.

9. The closed-type press static load deformation measurement system according to claim 8, characterized in that, Each hydraulic loader is arranged on the upper surface of the worktable, and is distributed in two equal rows along the preset loading range in the length and width directions of the worktable. The preset loading range is divided equally along the length direction by the number of loaders in each row, and equally along the width direction by the front and rear rows, forming multiple sub-regions of equal area. The geometric center of each sub-region is the geometric center of the corresponding hydraulic loader.

10. The closed-type press static load deformation measurement system according to claim 8, characterized in that, Also includes: microcontroller; The microcontroller is electrically connected to the hydraulic loader, the first indicator (P1), the second indicator (P2), the third indicator (P3), the fourth indicator (P4), the fifth indicator (P5), and the sixth indicator (P6), respectively. The microcontroller loads the press worktable in segments using a hydraulic loader. The load starts from zero and increases gradually in increments of one-fifth, two-fifths, three-fifths, four-fifths, and five-fifths of the nominal force. After each loading, the readings of the first indicator (P1), the second indicator (P2), the third indicator (P3), the fourth indicator (P4), the fifth indicator (P5), and the sixth indicator (P6) are recorded. Based on the readings of the first indicator (P1), the second indicator (P2), the third indicator (P3), and the fourth indicator (P4) under each load level, calculate their arithmetic mean, which is taken as the average relative deformation of the press under that load level. Based on the readings of the first indicator (P1), the second indicator (P2), and the fifth indicator (P5) under the nominal force load, as well as the span between the measuring points of the first indicator (P1) and the second indicator (P2), the left and right deflection of the bottom surface of the slider under the uniformly distributed load is calculated. Based on the readings of the sixth indicator (P6) under the nominal force load and the center distance between the left and right platform legs, the left and right deflections of the worktable under the uniformly distributed load are calculated.

Images