A method and production line for equal grinding of blank holders for automotive stamping parts dies

Abstract

This invention relates to a method and production line for equal grinding of the pressure plate of an automotive stamping die; the method includes: simultaneously coloring all balance blocks; maintaining the correct order of all balance blocks and the adjusting shims below them; drilling holes in different feature surfaces of the previous process part; placing the resulting part on the punch and placing lead wire; adjusting the press closing height to establish the pressure energy of the pressure plate; measuring the thickness of the lead wire on different feature surfaces of the die; replacing the part and brushing colorant on both sides; reinstalling the balance blocks and corresponding shims; adjusting the press closing height to the pressure plate grinding height; adjusting all balance block shims at the same height until the balance block coloring reaches more than 95%; repeatedly grinding the hard spots of the pressure plate according to the coloring of the front and back sides of the part; finely grinding the pressure plate until the part is free of pressure-damaged hard spots; this invention reduces the influence of CNC machining errors and differences in the balance of different presses, shortens the die grinding and debugging cycle, and improves the production stability of automotive stamping dies.

Description

Technical Field

[0001] This invention belongs to the field of automotive stamping die grinding technology, and relates to a method and production line for equal grinding of automotive stamping die pressure plate. Background Technology

[0002] The working principle of automotive stamping dies is as follows Figure 1 The workpiece is placed on the lower die. The pressure plate, powered by a nitrogen spring or press, presses the workpiece before the working part of the upper die, ensuring the workpiece's shape perfectly conforms to both dies. Once the workpiece is stably conformed, the die begins to work on it. The function of the pressure plate is to ensure a stable fit between the workpiece and the die. Balance blocks and shims are installed between the pressure plate and the lower die to balance the gap between them, ensuring a uniform and stable gap. Due to machining errors and die deformation under stress, the workpiece may not perfectly conform between the pressure plate and the lower die. To ensure a uniform gap of one material thickness between the pressure plate and the lower die, the pressure plate needs to be ground by a fitter to guarantee the workpiece's conformation and stability. This invention provides a method and production line for equal-weight grinding of the pressure plate of an automotive stamping die.

[0003] Traditional methods for grinding automotive mold blanks involve grinding directly after the mold is assembled, without measuring the grinding gap, and then adjusting the height of the balance blocks after grinding. This method significantly increases the grinding cycle and workload for fitters due to the accumulation of CNC machining and assembly errors. Furthermore, when molds are manufactured by different stamping equipment or transferred to OEMs during production debugging, the coloring of the mold blanks can change due to differences in the precision of the stamping equipment, directly affecting the stability of mold debugging and mass production. Since the mounting surfaces of different presses are not perfectly level, differences between presses can exist, greatly impacting mold fitting. This often requires a significant amount of time for refitting, extending the mold delivery cycle.

[0004] Patent document CN106944899A provides a method for grinding and polishing automotive molds, including the following steps: if geometric accuracy is not considered, only steps S3-S4 are performed; otherwise, steps S1-S4 are performed.

[0005] S1. Before polishing, inspect the surface of the mold body for machining marks. S2. Roughly polish the mold surface with a 320# diamond fiber oilstone to remove tool marks and burrs. S3. Perform semi-finish polishing with 500#, 700#, 900#, 1100#, and 1300# abrasive pads in sequence to remove machining marks. Before changing to different grades of abrasive pads, wipe the mold body surface with 100% pure cotton soaked in alcohol and check the polishing condition. S4. Apply 35000# polishing compound to the polishing wheel and perform mirror-finish polishing on the mold surface. This polishing method for automotive headlight molds is simple, requires low labor intensity, greatly shortens the polishing cycle, and reduces mold production costs. Molds produced using this method have a smooth and high-precision surface.

[0006] The aforementioned patent document relates to a polishing method for automotive headlight molds.

[0007] Patent document CN111974884A provides a method for improving the R-angle fit rate of stamping dies for automotive body panels, belonging to the field of automotive mold manufacturing, specifically involving a method for improving the R-angle fit rate of stamping dies. Through the development and application of gap shaping technology, the concave R-angle of the die surface is reduced before actual machining, significantly improving the R-angle fit rate of the die. The method involves reducing the radius of curvature of the concave R-angle of the die surface, while keeping the corresponding convex R-angle unchanged, thereby increasing the gap between the upper and lower dies at the R-angle location to compensate for the machining residue from small-diameter tools. Depending on the size of the radius of curvature, it is reduced by 0.5–1 mm while ensuring continuity with adjacent curved surfaces. By increasing the gap between the upper and lower dies at the R-angle location to compensate for the machining residue from small-diameter tools, the machining process becomes more standardized, the rough workmanship mode is upgraded to a technical standard, the degree of CNC is greatly improved, the on-site workload is reduced, the debugging time is shortened, the manual grinding time and error of fitters are reduced, and the efficiency and quality of the finishing process are improved.

[0008] The aforementioned patent documents are not very relevant to this application. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the problem that the accumulation of errors in CNC machining and assembly in the prior art greatly increases the fitter's grinding cycle and workload, and to provide a method for equal grinding of the pressure plate of automotive stamping part mold.

[0010] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0011] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution:

[0012] A method for grinding a die pressure plate in equal quantities includes the following steps:

[0013] S1. Empty the mold, adjust the pressure plate and the adjusting shims under the balance block so that all balance blocks are colored at the same time.

[0014] S2. Remove all balance weights, and ensure that the order of all balance weights and the adjusting shims under the balance weights is not disordered;

[0015] S3. Drill holes in the feature surfaces of different areas of the part made in the previous process to place the measuring wire, and prepare the wire at the same time.

[0016] S4. Place the part obtained in S3 on the punch and place the lead wire.

[0017] S5. The press closing height is adjusted to the point where the pressure of the pressure plate can be established, and the workpiece in S4 is not trimmed or shaped. Record the value of the closing height as the pressure plate fitting height.

[0018] S6. Measure the thickness of the lead wire on different characteristic surfaces of the mold;

[0019] S7. Replace the part in S5, brush colorant on both sides, and place it on the punch.

[0020] S8. Reinstall the balance weights and corresponding shims;

[0021] S9. Adjust the press closing height to the pressure plate fitting height, and press the press for one return stroke;

[0022] S10. Observe the coloring of the pressure plate and the balance block. Add or subtract all the balance block shims at the same height until the coloring of the balance block reaches more than 95%. Then, according to the coloring of the front and back of the part in S7, grind the hard spots of the pressure plate.

[0023] S11. Repeat step S10, and polish multiple times until the coloring of the pressure plate is greater than 60% and the coloring of all balance blocks is greater than 95%.

[0024] S12. Replace the part obtained in S10, repeat step S10, and polish multiple times until the color of the pressure plate is greater than 70% and the color of all balance blocks is greater than 95%.

[0025] S13. Replace the part obtained in S12, repeat step S10, and polish multiple times until the color of the pressure plate is greater than 80% and the color of all balance blocks is greater than 95%; polish the pressure plate.

[0026] S14. Replace the part obtained in S13, repeat step S10, and perform fine polishing multiple times until the coloring of the pressure plate is greater than 85% and the coloring of all balance blocks is greater than 95%; polish the pressure plate.

[0027] S15. Close the press and adjust it to the bottom dead center. Use the part obtained in S14 to press it. Check the pressure plate for hard spots and repair them.

[0028] S16. Replace the part obtained in S15, press it again, and finely grind the pressure plate until the part is free of pressure damage and hard spots.

[0029] Furthermore, the lead wire is selected to be 1.5 times the thickness of the sheet material.

[0030] Furthermore, in S6, the thickness of the lead wire is measured on different feature surfaces of the mold. If it exceeds the actual thickness of the sheet metal after the part is formed by more than 0.1 mm, or if Δ is greater than the machining error allowed by CNC, the mold is returned to CNC for reprocessing. The value of subtracting the actual thickness of the sheet metal at the measurement position from the thickness of the lead wire is recorded as Δ.

[0031] Furthermore, in S4, the part obtained in S3 is placed on the punch, lead wire is placed, and it is fixed with putty to prevent the lead wire from shifting.

[0032] Furthermore, in S4, the part obtained in S3 is placed on the punch, lead wire is placed, and it is fixed with adhesive oil to prevent the lead wire from shifting.

[0033] Furthermore, the thickness of the mating plate for the side mold trimming pressure plate is 0.8 mm.

[0034] Furthermore, in S10, all balance blocks are fitted with 0.05mm shims at the same height.

[0035] Further, in S13, replace the new part and repeat step S10. At this time, the coloring of the pressure plate is uniform and light, and the balance block shim is removed by 0.05 mm.

[0036] A production line for grinding the blank holder of an automotive stamping part die in equal quantities includes a die, which includes an upper die, a blank holder, and a lower die. During the grinding process of the blank holder, the pressure of the blank holder is provided by a nitrogen cylinder, polyurethane, or a press.

[0037] Furthermore, the pressure plate of the mold is obtained by grinding the pressure plate of the mold according to any one of claims 1-9 in equal quantities.

[0038] Compared with the prior art, the beneficial effects of the present invention are:

[0039] This invention achieves precise grinding of the pressure plate by accurately measuring the grinding gap before mold repair and scientifically adjusting the mold balance block, thereby reducing the impact of CNC machining errors and differences in the balance of different presses, shortening the mold grinding and debugging cycle, and improving the production stability of automotive stamping parts molds. Attached Figure Description

[0040] The invention will now be further described with reference to the accompanying drawings:

[0041] Figure 1 This is a flowchart of a method for equal grinding of a blank holder for an automotive stamping part according to the present invention;

[0042] Figure 2 A schematic diagram of the working process of an automotive stamping die;

[0043] Figure 3 This is a schematic diagram of the structure of an automotive stamping die. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The embodiments of this invention will be described in detail below with reference to the accompanying drawings.

[0045] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0046] The present invention will now be described in detail with reference to the accompanying drawings:

[0047] A method for grinding the pressure plate of an automotive stamping die in equal quantities involves grinding the pressure plate of the die, wherein the die has an upper die, a pressure plate, and a lower die, and the pressure of the pressure plate is provided by a nitrogen cylinder, polyurethane, or a press during the grinding process.

[0048] The technical solution adopted in this invention is: a method for equal-volume grinding of automotive mold pressure plates, comprising the following steps:

[0049] (1) Empty the mold, adjust the pressure plate and the adjusting shims under the balance block so that all balance blocks are colored at the same time;

[0050] (2) Remove all balance blocks, and ensure that the order of all balance blocks and the adjusting shims under the balance blocks is not disordered;

[0051] (3) Drill holes in the feature surfaces of different areas of the previous process part to place the measuring lead wire. At the same time, prepare the lead wire. The lead wire should be 1.5 times the thickness of the sheet material.

[0052] (4) Place the workpiece on the punch and place the lead wire. You can use clay or adhesive oil to fix it to prevent the lead wire from shifting.

[0053] The part is a product produced by the mold, and the previous process part is a product produced by the previous process mold. Generally, when grinding and coloring the pressure plate, it is necessary to use the part produced by the previous process mold.

[0054] (5) When the press closing height is adjusted to the point where the pressure of the pressure plate can be established, and the workpiece is not trimmed or shaped, record the value of the closing height as the pressure plate fitting height.

[0055] (6) Measure the thickness of the lead wire on different feature surfaces of the mold. If it exceeds the actual thickness of the sheet metal after the part is formed by more than 0.08 mm, (here, the value of the thickness of the lead wire minus the actual thickness of the sheet metal at the measurement position is recorded as Δ) that is, Δ>0.08 mm, or Δ is greater than the machining error allowed by CNC, it is recommended that the mold be returned to CNC for reprocessing.

[0056] (7) Replace the part, brush colorant on both sides, and place it on the punch;

[0057] (8) Reinstall the balance weights and corresponding shims;

[0058] (9) Adjust the press closing height to the pressure plate fitting height, and press the press for one return stroke;

[0059] (10) Observe the coloring of the pressure plate and the balance block, add or subtract all the balance block shims at the same height until the coloring of the balance block reaches more than 95%, and then grind the hard spots of the pressure plate according to the coloring of the front and back of the part.

[0060] (11) Repeat step (10) and polish multiple times until the coloring of the pressure plate is greater than 60% and the coloring of all balance blocks is greater than 95%.

[0061] (12) Replace with a new part and repeat step (10). Polish multiple times until the color of the pressure plate is greater than 70% and the color of all balance blocks is greater than 95%.

[0062] The coloring of parts used in the lamination and fitting process typically becomes inaccurate after three rounds of testing, necessitating frequent replacement with new parts for lamination and fitting. The "new parts" mentioned here refer to new parts from the preceding process, not the same part as the original. Parts, process parts, and new parts are all products pressed from molds.

[0063] (13) Replace with a new part and repeat step (10), grinding multiple times until the material is pressed.

[0064] The coloring of the board is greater than 80%, and the coloring of all balance blocks is greater than 95%; push-burning pressure plate.

[0065] (14) Replace with a new part and repeat step (10), polishing repeatedly until the surface is smooth and even.

[0066] The pressure plate is colored more than 85%, and all balance blocks are colored more than 95%; the pressure plate is polished.

[0067] (15) After the press is closed and adjusted to the bottom dead center, place the workpiece that was painted in the previous process onto the convex part.

[0068] On the mold, the press performs one stroke to check for pressure marks and hard spots on the part, and performs grinding and repair on the corresponding pressure plate area.

[0069] The part here is the part used to confirm the grinding area during the grinding process. It is the part pressed out by the pressure plate after the previous process part has been painted.

[0070] (16) Replace with a new part, brush the previous part with color again and place it on the punch. Press it for one stroke, check the part for pressure damage and hard spots, and finely grind the pressure plate until the part is free of pressure damage and hard spots.

[0071] This invention provides an equal-weight grinding method for automotive mold blank holders, which can verify the inherent accuracy of the mold after CNC machining and eliminate accumulated machining errors from CNC and assembly processes.

[0072] It can avoid repeated mold preparation and debugging, shorten the manufacturing and debugging cycle; it can avoid repeated mold preparation and debugging after the mold is transferred to another site; it can improve mold production efficiency; and it can increase the service life of the mold.

[0073] Example: The thickness of the mating sheet material for the trimming and pressing plate of the side panel mold of a certain car model is 0.8MM.

[0074] A method for grinding equal quantities of pressure plates for automotive molds includes the following steps:

[0075] S1. Empty the mold and adjust the balance block shims of the pressure plate to make all balance blocks color at the same time.

[0076] S2. Remove all balance weights, ensuring that the order of all balance weights and their adjusting shims is not disordered;

[0077] S3. Drill holes in the feature surfaces of different areas of the part manufactured in the previous process;

[0078] S4. Place the workpiece on the punch, place a lead wire at the drilled hole, and use clay or grease to stick the lead wire to the punch to prevent it from slipping off.

[0079] S5. Adjust the press closing height to the height of the pressure plate. At this time, the pressure of the pressure plate can be established and the workpiece is not trimmed.

[0080] S6. Measure the thickness of the lead wire on different feature surfaces of the mold. If Δ = 0.08 mm, the processing is deemed qualified and the pressure plate can be prepared.

[0081] S7. Replace the part, brush colorant on both sides, and place it on the punch.

[0082] S8. Reinstall the balance weights and corresponding shims;

[0083] S9. Adjust the press closing height to the height of the pressure plate; press the press for one return stroke;

[0084] S10. Observe the coloring of the pressure plate and balance blocks. It was found that the coloring of one balance block was incomplete. All balance blocks were then fitted with 0.05mm shims at the same height to ensure that all balance blocks were properly colored. Afterwards, the hard spots on the pressure plate were polished and repaired.

[0085] S11. Repeat step (10) and polish multiple times until the coloring of the pressure plate is greater than 60% and the coloring of all balance blocks is greater than 95%.

[0086] S12. Replace with a new part and repeat step (10). Polish multiple times until the coloring of the pressure plate is greater than 70% and the coloring of all balance blocks is greater than 95%.

[0087] S13. Replace with a new part and repeat step (10). At this time, the coloring of the pressure plate is uniform and light. Remove the balance block shims by 0.05 mm. Polish multiple times until the coloring of the pressure plate is greater than 80% and the coloring of all balance blocks is greater than 95%; polish the pressure plate.

[0088] S14. Replace with a new part and repeat step (10). Polish repeatedly until the color of the pressure plate is greater than 85% and the color of all balance blocks is greater than 95%. Polish the pressure plate.

[0089] S15. After closing the press and adjusting it to the bottom dead center, press one stroke using 85% colored parts, check the workpiece for pressure marks and hard spots, and perform grinding and repair on the corresponding pressure plate area.

[0090] S16. Replace with a new part, and place the previous part on the punch after painting it again. Press it for one stroke, check the part for pressure marks and hard spots, and finely grind the pressure plate until the part is free of pressure marks and hard spots.

[0091] This invention provides a method for equal-weight grinding of automotive mold pressure plates. By adjusting the balance blocks to ensure equal weight, the pressure plate is not affected by lateral forces during grinding, preventing uneven loading of the mold. Measurement of lead wire verifies whether the CNC machining meets the grinding requirements and verifies the grinding workload. Coloring the front and back of the workpiece accurately locates the grinding area of ​​the pressure plate, reducing the grinding cycle. This invention involves multiple parts replacements and repeated grinding to ensure accuracy. The coloring rate of the pressure plate reaches 85%, and the coloring rate of the balance blocks reaches 95%.

[0092] This invention provides another embodiment of a production line for the equal-quantity grinding of pressure plates for automotive stamping parts dies, comprising a die, which includes an upper die, a pressure plate, and a lower die. During the grinding process of the pressure plate, the pressure of the pressure plate is provided by a nitrogen cylinder, polyurethane, or a press. The pressure plate of the die is obtained by grinding using the aforementioned method for equal-quantity grinding of die pressure plates.

[0093] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be included within the scope of protection of the present invention. Furthermore, all content not described in detail in this specification is prior art known to those skilled in the art.

Claims

1. A method for grinding equal amounts of mold pressure plates, characterized in that, Includes the following steps: S1. Empty the mold, adjust the pressure plate and the adjusting shims under the balance block so that all balance blocks are colored at the same time. S2. Remove all balance weights, and ensure that the order of all balance weights and the adjusting shims under the balance weights is not disordered; S3. Drill holes in the feature surfaces of different areas of the part made in the previous process to place the measuring wire, and prepare the wire at the same time. S4. Place the part obtained in S3 on the punch and place the lead wire. S5. The press closing height is adjusted to the point where the pressure of the pressure plate can be established, and the workpiece in S4 is not shaped. Record the value of the closing height as the pressure plate fitting height. S6. Measure the thickness of the lead wire on different characteristic surfaces of the mold; S7. Replace the part in S5, brush colorant on both sides, and place it on the punch. S8. Reinstall the balance weights and corresponding shims; S9. Adjust the press closing height to the pressure plate fitting height, and press the press for one return stroke; S10. Observe the coloring of the pressure plate and the balance block. Add or subtract all the balance block shims at the same height until the coloring of the balance block reaches more than 95%. Then, according to the coloring of the front and back of the part in S7, grind the hard spots of the pressure plate. S11. Repeat step S10, and polish multiple times until the coloring of the pressure plate is greater than 60% and the coloring of all balance blocks is greater than 95%. S12. Replace the part obtained in S10, repeat step S10, and polish multiple times until the coloring of the pressure plate is greater than 70% and the coloring of all balance blocks is greater than 95%. S13. Replace the part obtained in S12, repeat step S10, and polish multiple times until the color of the pressure plate is greater than 80% and the color of all balance blocks is greater than 95%; polish the pressure plate. S14. Replace the part obtained in S13, repeat step S10, and perform fine polishing multiple times until the coloring of the pressure plate is greater than 85% and the coloring of all balance blocks is greater than 95%; polish the pressure plate. S15. Close the press and adjust it to the bottom dead center. Use the part obtained in S14 to press it. Check the pressure plate for hard spots and repair them. S16. Replace the part obtained in S15, press it again, and finely grind the pressure plate until the part is free of pressure damage and hard spots.

2. The method for equal grinding of a mold pressure plate according to claim 1, characterized in that: The lead wire should be 1.5 times the thickness of the sheet material.

3. The method for equal grinding of a mold pressure plate according to claim 1, characterized in that: In S6, the thickness of the lead wire on different feature surfaces of the mold is measured. If it exceeds the actual thickness of the sheet metal after the part is formed by more than 0.1 mm, the mold is returned to CNC for reprocessing.

4. The method for equal grinding of a mold pressure plate according to claim 1, characterized in that: In S4, the part obtained in S3 is placed on the punch, lead wire is placed, and it is fixed with putty to prevent the lead wire from shifting.

5. The method for equal grinding of a mold pressure plate according to claim 1, characterized in that: In S4, the part obtained in S3 is placed on the punch, lead wire is placed, and it is fixed with adhesive oil to prevent the lead wire from shifting.

6. The method for equal grinding of a mold pressure plate according to claim 1, characterized in that: The thickness of the mating plate for the side panel mold trimming and pressing plate is 0.8 mm.

7. The method for equal grinding of a mold pressure plate according to claim 1, characterized in that: In S10, all balance blocks are placed at the same height with 0.05mm shims.

8. The method for grinding a mold pressure plate in equal quantities according to claim 1, characterized in that, In step S13, replace the new part and repeat step S10. At this time, the coloring of the pressure plate is uniform and light. Remove the balance block shim by 0.05 mm.

9. A production line for equal grinding of pressure plates for automotive stamping parts dies, characterized in that: The mold includes an upper mold, a pressure plate, and a lower mold. During the grinding process of the pressure plate, the pressure of the pressure plate is provided by a nitrogen cylinder or a press. The pressure plate of the mold is obtained by grinding the pressure plate of the mold as described in any one of claims 1-8.

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