Blank holder force detection method of stamping equipment

Abstract

The invention provides a blank holder force detection method for stamping equipment, and belongs to the technical field of stamping production. The blank holder force detection method comprises the following steps: stamping a test piece; the blank holder force P at the first blank holder is obtained; when the stamped test piece cracks and / or wrinkles, the blank holder force P is the defect blank holder force P defect; recording a defect blank holder force P defect and establishing a defect blank holder force P defect threshold value, wherein the defect blank holder force P defect threshold value comprises a blank holder force over-large threshold value and a blank holder force over-small threshold value; in the production process, the blank holder force P at the first blank holder is detected, the blank holder force P is compared with the defect threshold value of the defect blank holder force P, and if the blank holder force P is larger than the overlarge threshold value of the blank holder force or smaller than the undersmall threshold value of the blank holder force, an alarm is given out.

Description

Technical Field

[0001] The invention relates to the technical field of stamping production, and in particular to a method for detecting the blank holding force of a stamping device. Background Art

[0002] When stamping a plate, the upper and lower pressure rings of the stamping equipment clamp the plate in the middle to limit the material feeding speed of the plate. If the pressure is too high, the gap between the upper and lower pressure rings will be smaller than the normal gap, which will reduce the material feeding speed during the stretching process, resulting in easy cracking. If the pressure is too low, the gap between the upper and lower dies will be larger than the normal gap, which will make the material feeding speed during the stretching process too fast, resulting in easy wrinkling.

[0003] Before the stamping equipment leaves the factory, the stamping equipment manufacturer needs to measure and debug the blank holding force of the stamping equipment test platform to obtain standard parameters, under which qualified products without cracking and / or wrinkling can be pressed out. When the finished stamping equipment leaves the factory, due to machine errors and variations, the blank holding force of the stamping equipment after leaving the factory needs to be measured and debugged again based on the factory parameters before it can be put into stamping production.

[0004] In the existing blank holder force measurement, blue tan oil is applied to the balance block of the blank holder ring. After the die completes a stamping operation, the gap between the upper and lower blank holder rings is judged to be large or small by observing the color depth of the blue tan oil applied to the balance block. Since the pressure value cannot be quantified by the manual blue tan oil application method, it is entirely based on subjective and empirical judgment, which makes it impossible to make an accurate judgment. As a result, the parameters debugged are quite different from the factory parameters, and the stamped product may crack and / or wrinkle. In addition, the pressure cannot be monitored in real time during the stamping process, and parameters cannot be provided for production quality monitoring. Summary of the invention

[0005] The purpose of the present invention is to provide a method for detecting the blank holding force of a stamping equipment, which solves the defect that the blank holding force cannot be accurately quantified due to manually judging whether the gap between the upper and lower blank holding rings is large or small by looking at the depth of the color of the blue oil pressed on the balance block. It realizes real-time monitoring of the pressure during production after mass production, provides an accurate threshold for monitoring production quality, and quantifies the pressure value in the key area, which serves as a reference for debugging the stamping equipment back to the production line.

[0006] To achieve the purpose of the present invention, the present invention adopts the following technical solutions:

[0007] The present invention provides a blank holding force detection method for a stamping device, wherein the stamping device comprises at least one pressure sensor, a first mold, a second mold, a first blank holding ring, a second blank holding ring and a blank holding cylinder, wherein the first mold and the second mold are arranged relatively to each other and configured to cooperate with each other to form a plate, wherein the first blank holding ring is movably arranged on the first mold, and the first blank holding ring surrounds the first mold, and the second blank holding ring is arranged on the second mold corresponding to the first blank holding ring, the blank holding cylinder is connected to the first blank holding ring, and the pressure sensor is arranged between the first blank holding ring and the second blank holding ring, and the pressure sensor is configured to measure the blank holding force applied by the first blank holding ring; the blank holding force detection method comprises:

[0008] Punching the test piece;

[0009] Obtain the blank holding force P at the first blank holding circle;

[0010] When cracks and / or wrinkles are present on the test piece after stamping, the blank holding force P is the defective blank holding force P. 缺陷 ;

[0011] Record defect blank holding force P 缺陷 And establish the defect blank holding force P 缺陷 Threshold value, blank holding force P 缺陷 The thresholds include the threshold of excessive blank holder force and the threshold of insufficient blank holder force;

[0012] During the production process, the blank holder force P at the first blank holder ring is tested, and the blank holder force P and defective blank holder force P are tested. 缺陷 If the blank holder force P is greater than the excessive blank holder force threshold or less than the insufficient blank holder force threshold, an alarm is issued.

[0013] According to one embodiment of the present invention, obtaining the blank holding force generated at the first blank holding ring includes: a plurality of pressure sensors are installed on the first blank holding ring at intervals, and when the first blank holding ring and the second blank holding ring jointly clamp the edge of the test piece, the pressure sensor abuts against the second blank holding ring to obtain the blank holding force P.

[0014] According to an embodiment of the present invention, obtaining the blank holder force P generated at the first blank holder ring further comprises: punching out a plurality of test pieces, and measuring the blank holder force P in real time when punching each test piece. 实 , real-time recording of blank holding force P 实 .

[0015] According to one embodiment of the present invention, when cracks and / or wrinkles occur in the test piece after stamping, the blank holding force P is a defective blank holding force P. 缺陷 Including: After each test piece is stamped, take it out and observe whether there are defects. If there are defects, the blank holding force P corresponding to the defective test piece is 实 Determined as defective blank holding force P 缺陷 .

[0016] According to an embodiment of the present invention, before stamping the test piece, the method further includes: controlling the output pressure of the edge holding cylinder so that the output pressure of the edge holding cylinder set for each test piece before stamping is different.

[0017] According to an embodiment of the present invention, a plurality of balancing blocks for abutting against the second blank holder ring are arranged on the first blank holder ring, and before the test piece is punched, a different number of gaskets are arranged on each balancing block.

[0018] According to one embodiment of the present invention, a top block is provided corresponding to the pressure sensor in the second pressure ring, and the abutment surface of the top block matches the sensing surface of the pressure sensor, and when the second pressure ring and the first pressure ring jointly clamp the test piece, the sensing surface of the pressure sensor abuts against the abutment surface of the top block.

[0019] According to one embodiment of the present invention, it also includes obtaining the parameters of the parallelism of the first blank holder ring and the second blank holder ring, comparing the parameters of the parallelism with a preset standard parallelism threshold, if the parameters of the parallelism exceed the standard parallelism threshold, it is determined that the first blank holder ring and the second blank holder ring are not parallel; if the obtained parameters of the parallelism are within the standard parallelism threshold, it is determined that the first blank holder ring and the second blank holder ring are parallel.

[0020] According to an embodiment of the present invention, obtaining the parameters of the parallelism of the first blank holder and the second blank holder includes: obtaining the pressure difference P between the pressure sensors between the two 差 .

[0021] According to an embodiment of the present invention, after the stamping equipment is shipped to the production line and before it is put into production, the stamping equipment is debugged, and the debugging includes:

[0022] Punching the test piece;

[0023] When there are multiple pressure sensors, if the blank holding force measured by at least one of the pressure sensors is greater than the excessive blank holding force threshold, the number of gaskets on the balancing block adjacent to the pressure sensor is increased accordingly;

[0024] If the blank holding force measured by at least one of the pressure sensors is less than the threshold value of the blank holding force being too small, the number of gaskets on the balancing block adjacent to the pressure sensor is correspondingly reduced or the gaskets are removed;

[0025] If the blank holding forces measured by all the pressure sensors are greater than the blank holding force excessive threshold, the output pressure of the blank holding cylinder is reduced accordingly;

[0026] If the blank holding forces measured by all the pressure sensors are less than the blank holding force too small threshold, the output pressure of the blank holding cylinder is increased accordingly;

[0027] Until the blank holding forces obtained by all pressure sensors are smaller than the blank holding force excessive threshold value and larger than the blank holding force insufficient threshold value.

[0028] An embodiment of the present invention has the following advantages or beneficial effects:

[0029] The present invention provides a blank holding force detection method for a stamping device, wherein the stamping device comprises at least one pressure sensor, a first die, a second die, a first blank holding ring, a second blank holding ring and a blank holding cylinder, wherein the first die and the second die are arranged relatively to each other and configured to cooperate with each other to form a plate, wherein the first blank holding ring is movably arranged on the first die, and the first blank holding ring surrounds the first die, and the second blank holding ring is arranged on the second die corresponding to the first blank holding ring, the blank holding cylinder is connected to the first blank holding ring, and the pressure sensor is arranged between the first blank holding ring and the second blank holding ring, and the pressure sensor is configured to measure the blank holding force applied by the first blank holding ring; the blank holding force detection method comprises:

[0030] Punching the test piece;

[0031] Obtain the blank holding force P at the first blank holding circle;

[0032] When cracks and / or wrinkles are present on the test piece after stamping, the blank holding force P is the defective blank holding force P. 缺陷 ;

[0033] Record defect blank holding force P 缺陷 And establish the defect blank holding force P 缺陷 Threshold value;

[0034] During the production process, the blank holder force P at the first blank holder ring is tested, and the blank holder force P and defective blank holder force P are tested. 缺陷 Threshold value is compared. If the blank holder force P is within the defect blank holder force P 缺陷 When the threshold is reached, an alarm is issued.

[0035] Since the pressure value measured by the pressure sensor is positively correlated with defects such as wrinkling and cracking, the pressure during production can be monitored in real time after the stamping die equipment is mass-produced, providing a threshold for monitoring production quality, so that the stamping die equipment has quantified pressure values ​​in key areas, which can be used as a reference for debugging the stamping die equipment when it returns to the production line. For example: the stamping die equipment is manufactured and debugged by the mold manufacturer and qualified parts are delivered, and its pressure sensor information is recorded as a standard parameter. When the stamping die equipment returns to the production line, due to machine errors and variations, cracking and wrinkling occur during the debugging process. By referring to the standard parameters of the pressure sensor pressure value before shipment and comparing it with the pressure value measured during the production line debugging, the debugging of the stamping equipment is completed. During debugging, if the blanking force measured by all sensors is greater than the blanking force threshold or less than the blanking force threshold, the output pressure of the blanking cylinder is reduced or increased accordingly until all pressure sensors measure The blank holding force is less than the threshold value of excessive blank holding force and greater than the threshold value of too small blank holding force; if the blank holding force measured by at least one of the pressure sensors is greater than the threshold value of excessive blank holding force or less than the threshold value of too small blank holding force, the number of gaskets on the balancing block adjacent to the position of the pressure sensor is increased or decreased accordingly until the blank holding force measured by the pressure sensor is less than the threshold value of excessive blank holding force and greater than the threshold value of too small blank holding force. There is no need to stop the machine and manually apply blue tan oil, which improves the accuracy of judgment and the efficiency of measurement and debugging, realizes real-time monitoring of the blank holding force during the forming process of stamping parts, and then realizes the ability to provide parameters for production quality monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and other features and advantages of the present invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings.

[0037] Figure 1 is a cross-sectional view showing a stamping device according to an exemplary embodiment.

[0038] Figure 2 is another cross-sectional view of a stamping device according to an exemplary embodiment.

[0039] Figure 3 The diagram is a schematic diagram showing the distribution of pressure sensors of a stamping device when stamping a side panel according to an exemplary embodiment.

[0040] Figure 4 The diagram is a schematic diagram showing the distribution of pressure sensors of a stamping device when stamping a door inner panel according to an exemplary embodiment.

[0041] The reference numerals are described as follows:

[0042] 1. Pressure sensor; 11. Mounting seat; 2. First mold; 3. Second mold; 4. First blank holder; 41. Balance block; 5. Second blank holder; 51. Top block; 6. Test piece. DETAILED DESCRIPTION

[0043] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present invention will be comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their detailed description will be omitted.

[0044] The terms "a", "an", "the", and "said" are used to indicate the presence of one or more elements / components / etc.; the terms "comprising" and "having" are used to express an open-ended inclusive meaning and mean that additional elements / components / etc. may be present in addition to the listed elements / components / etc.

[0045] like Figure 1-4 As shown, a method for detecting the blank holding force of a stamping equipment according to an embodiment of the present invention, wherein the stamping equipment includes at least one pressure sensor 1, a first mold 2, a second mold 3, a first blank holding ring 4, a second blank holding ring 5 and a blank holding cylinder.

[0046] The first mold 2 and the second mold 3 are arranged relatively to each other and configured to cooperate with each other to form the plate. For example, the second mold 3 is located directly above the first mold 2. During stamping, the second mold 3 moves downward perpendicular to the horizontal plane and stamps the plate together with the first mold 2.

[0047] The first pressure ring 4 is movably disposed on the first mold 2 , and the first pressure ring 4 surrounds the first mold 2 . The first pressure ring 4 has a clamping portion at its inner edge. The second pressure ring 5 is disposed on the second mold 3 corresponding to the first pressure ring 4 .

[0048] The edge holding cylinder is connected to the first edge holding ring 4 through the top rod of the workbench and drives the first edge holding ring 4 to move up and down. The force of the edge holding cylinder is controlled by adding and subtracting air pressure, for example, by inputting an MPa value through a controller parameter input module to operate.

[0049] The pressure sensor 1 is disposed between the first blank holder ring 4 and the second blank holder ring 5 and close to outer edges of the first blank holder ring 4 and the second blank holder ring 5 . The pressure sensor 1 is configured to measure the blank holding force applied by the first blank holder ring 4 .

[0050] When the plate is placed on the first mold 2, the second mold 3 moves downward and applies pressure to the plate toward the first mold 2. At the same time, the edge holding cylinder drives the first edge holding ring 4 upward to clamp the edge of the plate together with the second edge holding ring 5 to limit the feeding speed of the plate. At this time, the two ends of the pressure sensor 1 are respectively in contact with the first edge holding ring 4 and the second edge holding ring 5 to obtain the edge holding force at the first edge holding ring 4.

[0051] The blank holding force detection method comprises:

[0052] Punching the test piece 6;

[0053] Obtain the blank holding force P at the first blank holding ring 4;

[0054] When the test piece 6 has cracks and / or wrinkles after stamping, the blank holding force P is the defective blank holding force P. 缺陷 , and the defect blank holding force P 缺陷 Set as alarm parameter; when there is no cracking or wrinkling on the test piece 6, the blank holding force P is the qualified blank holding force P 合格 ;

[0055] The defect blank holding force P 缺陷 Set as alarm parameter, and set qualified blank holding force P 合格 Set to standard parameters;

[0056] Record defect blank holding force P 缺陷 And establish the defect blank holding force P 缺陷 Threshold value;

[0057] During the production process, the blank holding force P at the first blank holding ring 4 is detected, and the blank holding force P and the defective blank holding force P are compared. 缺陷 Threshold value is compared. If the blank holder force P is within the defect blank holder force P 缺陷 When it is within the threshold, an alarm is issued.

[0058] The blank holding force detection method of the present invention, since the obtained blank holding force is positively correlated with defects such as wrinkling and cracking, can monitor the blank holding force during production in real time after the stamping equipment is mass-produced, provide a threshold for monitoring production quality, and enable the stamping equipment to have a quantified pressure value in the key area, which can be used as a reference for debugging the stamping equipment back to the production line. There is no need to stop the machine and manually apply blue oil, which improves the accuracy of judgment and the efficiency of measurement and debugging, realizes real-time monitoring of the blank holding force during the stamping part forming process, and then realizes the ability to provide parameters for production quality monitoring.

[0059] In a preferred embodiment of the present invention, obtaining the blank holding force generated at the first blank holding ring 4 includes: a plurality of pressure sensors 1 are installed at intervals on the first blank holding ring 4, and when the first blank holding ring 4 and the second blank holding ring 5 jointly clamp the edge of the test piece 6, the pressure sensor 1 abuts against the second blank holding ring 5 to obtain the blank holding force P. By using a plurality of pressure sensors 1, the acquisition accuracy is further improved.

[0060] Optionally, each pressure sensor 1 is located close to a position where cracking and / or wrinkling of the test piece is likely to occur, so as to further improve the accuracy of the measurement. Figure 3 , 4As shown, the door inner panel and side panel of the vehicle are prone to cracking and / or wrinkling defects in the A, B, C, and D regions during stamping, and multiple pressure sensors 1 are arranged close to the A, B, C, and D regions, respectively.

[0061] In a preferred embodiment of the present invention, obtaining the blank holder force P generated at the first blank holder ring 4 further includes: punching out a plurality of test pieces 6, and measuring the blank holder force P in real time when punching each test piece 6. 实 , real-time recording of blank holding force P 实。 The multiple test pieces 6 include multiple defective test pieces and multiple qualified test pieces. For example, the multiple defective test pieces include at least one test piece with a wrinkling defect, at least one test piece with a cracking defect, and at least one test piece with both cracking and wrinkling defects. In this embodiment, multiple test pieces are used to enrich data information and reduce risks in the later production process.

[0062] Among them, the minimum value of the multiple blank holding forces recorded corresponding to the multiple cracked test pieces is the threshold value of excessive blank holding force, and the maximum value of the multiple blank holding forces recorded corresponding to the multiple wrinkled test pieces is the threshold value of insufficient blank holding force.

[0063] In a preferred embodiment of the present invention, when cracks and / or wrinkles are present in the test piece 6 after stamping, the blank holding force P is a defective blank holding force P. 缺陷 It includes: after each test piece 6 is stamped, take it out and observe whether it has defects. If it has defects, the blank holding force P corresponding to the defective test piece 6 is 实 Determined as defective blank holding force P 缺陷 . And the defect blank holding force P 缺陷 Input relevant alarm information items, for example, the alarm information items include cracking alarm items, wrinkling alarm items and cracking and wrinkling items, to establish defect blank holding force thresholds and data information of various defects.

[0064] If there is no defect, the blank holding force P corresponding to the defect-free test piece 6 is 实 The qualified blank holding force P 合格 . And the qualified blank holding force P 合格 Enter into the standard information item to establish the standard blank holder force threshold.

[0065] In a preferred embodiment of the present invention, before stamping the test piece 6, the process further includes: controlling the output pressure of the edge-holding cylinder so that the output pressure of the edge-holding cylinder set before stamping is different for each test piece 6, so as to obtain test pieces with various defects or qualified test pieces under different edge-holding cylinder output pressures, and enrich the detection threshold. For example, when the output pressure of the edge-holding cylinder is too large, a test piece with severe overall cracking can be obtained. When the output pressure of the edge-holding cylinder is too small, a test piece with severe overall wrinkling can be obtained.

[0066] like Figure 4 As shown, in a preferred embodiment of the present invention, a plurality of balancing blocks 41 for contacting with the second blank holder ring 5 are arranged on the first blank holder ring 4, and before punching the test piece 6, different numbers of gaskets are arranged on each balancing block 41. For example, increasing or decreasing the gaskets on the local balancing blocks 41 can adjust whether the test piece is partially wrinkled, partially cracked, or has no cracks and no wrinkles.

[0067] like Figure 1 , 2 As shown, in a preferred embodiment of the present invention, the second blank holder 5 is provided with a top block 51 corresponding to the pressure sensor 1, and the abutting surface of the top block 51 matches the sensing surface of the pressure sensor 1. When the second blank holder 5 and the first blank holder 4 jointly clamp the test piece 6, the sensing surface of the pressure sensor 1 abuts against the abutting surface of the top block 51, so as to improve the service life of the pressure sensor 1 and avoid damage to the sensing surface due to mismatch with the sensing surface. For example, when the sensing surface of the pressure sensor 1 is spherical, the abutting surface of the top block 51 is a corresponding arc groove. In addition, the concave and convex pressures can also achieve automatic alignment to avoid misaligned abutment.

[0068] When the sensing surface of the pressure sensor 1 abuts against the abutting surface of the top block 51 , the pressure sensor 1 generates different electrical signals according to different abutting pressures.

[0069] In a preferred embodiment of the present invention, it also includes obtaining the parameters of the parallelism of the first blank holder 4 and the second blank holder 5, comparing the parameters of the parallelism with the preset standard parallelism threshold value, if the parameters of the parallelism exceed the standard parallelism threshold value, it is determined that the first blank holder 4 and the second blank holder 5 are not parallel and trigger an alarm or a maintenance prompt; if the obtained parallelism parameters are within the standard parallelism threshold value, it is determined that the first blank holder 4 and the second blank holder 5 are parallel, so as to monitor the balance of the abutment force of various parts of the first blank holder 4 and the second blank holder 5 when they are abutted. When the abutment force of various parts of the first blank holder 4 and the second blank holder 5 is uneven, cracking and / or wrinkling defects are likely to occur.

[0070] In a preferred embodiment of the present invention, obtaining the parameters of the parallelism of the first blank holder 4 and the second blank holder 5 includes: obtaining the pressure difference P between the pressure sensors 1 of the two pressure sensors 1 差 For example, a first detection group and a second detection group are arranged on both sides of the first blank holder 4, and each of the first detection group and the second detection group includes two pressure sensors 1 to obtain the difference between the sum of the pressure values ​​of the first detection group and the sum of the pressure values ​​of the second detection group.

[0071] Of course, the first detection group and the second detection group are not limited to including two pressure sensors 1 , and those skilled in the art may select the number of pressure sensors 1 according to actual needs.

[0072] In one embodiment of the present invention, after the stamping equipment is shipped to the production line and before it is put into production, the stamping equipment is debugged, and the debugging of the stamping equipment includes:

[0073] Punching the test piece 6;

[0074] When there are multiple pressure sensors 1, for example, when there are eight pressure sensors 1, the multiple pressure sensors 1 are numbered respectively. If the blank holding force measured by the pressure sensor 1 numbered first and / or second is greater than the excessive blank holding force threshold, the number of gaskets on the balancing block 41 adjacent to the first and / or second pressure sensor 1 is increased accordingly to reduce the blank holding force at the first and / or second pressure sensor 1, until the blank holding forces measured by all the pressure sensors 1 are less than the excessive blank holding force threshold and greater than the insufficient blank holding force threshold, that is, until the blank holding forces measured by all the pressure sensors 1 are qualified blank holding forces P 合格 When the stamping part is partially cracked or wrinkled, the debugging is completed to carry out local debugging.

[0075] If the blank holding force measured by the pressure sensor 1 numbered first is smaller than the threshold value of the blank holding force being too small, the number of gaskets on the balancing block 41 adjacent to the pressure sensor 1 numbered first is reduced or the gaskets are removed accordingly to increase the blank holding force at the pressure sensor 1 numbered first, until the blank holding forces measured by all the pressure sensors 1 are smaller than the threshold value of the blank holding force being too large and larger than the threshold value of the blank holding force being too small, and the debugging is completed.

[0076] If the blank holding forces measured by all the pressure sensors 1 are greater than the excessive blank holding force threshold, the output pressure of the blank holding cylinder is reduced accordingly until the blank holding forces measured by all the pressure sensors 1 are less than the excessive blank holding force threshold and greater than the insufficient blank holding force threshold, and the debugging is completed.

[0077] If the blank holding forces measured by all the pressure sensors 1 are smaller than the threshold value of too small blank holding forces, the output pressure of the blank holding cylinder is increased accordingly until the blank holding forces measured by all the pressure sensors 1 are smaller than the threshold value of too large blank holding forces and larger than the threshold value of too small blank holding forces, and the debugging is completed.

[0078] In the embodiments of the present invention, the term "plurality" refers to two or more than two, unless otherwise clearly defined. The terms "installation", "connection", "fixation" and the like should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0079] In the description of the embodiments of the present invention, it needs to be understood that the directions or positional relationships indicated by the terms "upper" and "lower" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the embodiments of the present invention.

[0080] In the description of this specification, the description of the terms "one embodiment", "a preferred embodiment", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0081] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting the blank holding force of a stamping equipment, characterized in that: The stamping equipment comprises at least one pressure sensor (1), a first mold (2), a second mold (3), a first blank holder ring (4), a second blank holder ring (5) and a blank holder cylinder; the first mold (2) and the second mold (3) are arranged relative to each other and configured to cooperate with each other to form a plate; the first blank holder ring (4) is movably arranged on the first mold (2), and the first blank holder ring (4) surrounds the first mold (2); the second blank holder ring (5) is arranged on the second mold (3) corresponding to the first blank holder ring (4); the blank holder cylinder is connected to the first blank holder ring (4); the pressure sensor (1) is arranged between the first blank holder ring (4) and the second blank holder ring (5); the pressure sensor (1) is configured to measure the blank holder force applied by the first blank holder ring (4); The blank holding force detection method comprises: Punching the test piece (6); Obtaining the blank holding force P at the first blank holding ring (4); When the test piece (6) is cracked and / or wrinkled after stamping, the blank holding force P is a defective blank holding force P. 缺陷 ; Record defect blank holding force P 缺陷 And establish the defect blank holding force P 缺陷 Threshold value, the defect blank holding force P 缺陷 The thresholds include the threshold of excessive blank holder force and the threshold of insufficient blank holder force; During the production process, the blank holding force P at the first blank holding ring (4) is detected, and the blank holding force P and the defective blank holding force P are compared. 缺陷 If the blank holder force P is greater than the excessive blank holder force threshold or less than the insufficient blank holder force threshold, an alarm is issued.

2. The blank holding force detection method according to claim 1, characterized in that: The method for obtaining the blank holding force generated at the first blank holding ring (4) comprises: a plurality of pressure sensors (1) are installed at intervals on the first blank holding ring (4), and when the first blank holding ring (4) and the second blank holding ring (5) jointly clamp the edge of the test piece (6), the pressure sensor (1) abuts against the second blank holding ring (5) to obtain the blank holding force P.

3. The blank holding force detection method according to claim 2, characterized in that: The step of obtaining the blank holding force P generated at the first blank holding ring (4) further comprises: punching out a plurality of test pieces (6), and measuring the blank holding force P in real time when punching each test piece (6). 实 , real-time recording of the blank holding force P 实。 4. The blank holding force detection method according to claim 1, characterized in that: When the test piece (6) is cracked and / or wrinkled after stamping, the blank holding force P is a defective blank holding force P. 缺陷 The process comprises: taking out each test piece (6) after stamping to observe whether there is a defect; if there is a defect, the blank holding force P corresponding to the defective test piece (6) is increased. 实 Determined as defective blank holding force P 缺陷 .

5. The blank holding force detection method according to claim 1, characterized in that: Before the test piece (6) is stamped, the method further includes: controlling the output pressure of the edge holding cylinder so that the output pressure of the edge holding cylinder set for each test piece (6) before stamping is different.

6. The blank holding force detection method according to claim 5, characterized in that: The first blank holder ring (4) is provided with a plurality of balancing blocks (41) for abutting against the second blank holder ring (5), and before the test piece (6) is punched, it also includes: different numbers of gaskets are provided on each balancing block (41).

7. The blank holding force detection method according to claim 1, characterized in that: The second pressure ring (5) is provided with a top block (51) corresponding to the pressure sensor (1), and the abutment surface of the top block (51) matches the sensing surface of the pressure sensor (1); when the second pressure ring (5) and the first pressure ring (4) jointly clamp the test piece (6), the sensing surface of the pressure sensor (1) abuts against the abutment surface of the top block (51).

8. The blank holding force detection method according to claim 1, characterized in that: The method further includes obtaining the parameters of the parallelism of the first blank holder ring (4) and the second blank holder ring (5), comparing the parameters of the parallelism with a preset standard parallelism threshold value, and if the parameters of the parallelism exceed the standard parallelism threshold value, determining that the first blank holder ring (4) and the second blank holder ring (5) are not parallel; if the obtained parameters of the parallelism are within the standard parallelism threshold value, determining that the first blank holder ring (4) and the second blank holder ring (5) are parallel.

9. The blank holding force detection method according to claim 8, characterized in that: The method of obtaining the parameters of the parallelism of the first blank holder (4) and the second blank holder (5) comprises: obtaining the pressure difference P between the pressure sensors (1) 差 .

10. The blank holding force detection method according to claim 1, characterized in that: After the stamping equipment is shipped out of the factory to the production line and before it is put into production, the stamping equipment is debugged, and the debugging includes: Punching the test piece (6); When there are multiple pressure sensors (1), if the blank holding force measured by at least one of the pressure sensors (1) is greater than the blank holding force excessive threshold, the number of gaskets on the balancing block (41) adjacent to the pressure sensor (1) is increased accordingly; If the blank holding force measured by at least one of the pressure sensors (1) is less than the blank holding force too small threshold, the number of gaskets on the balancing block (41) adjacent to the pressure sensor (1) is correspondingly reduced or the gaskets are removed; If the blank holding forces measured by all the pressure sensors (1) are greater than the blank holding force excessive threshold, the output pressure of the blank holding cylinder is reduced accordingly; If the blank holding forces measured by all the pressure sensors (1) are smaller than the blank holding force too small threshold, the output pressure of the blank holding cylinder is increased accordingly; Until the blank holding forces obtained by all the pressure sensors (1) are smaller than the blank holding force excessive threshold value and larger than the blank holding force insufficient threshold value.

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