A stamping method for stable production using multi-action dies on a single-action press

Abstract

This invention provides a stamping method for stable production using multi-action dies on a single-action press. The method involves adjusting the pressure P1 of the upper air cushion and / or the pressure P2 of the lower air cushion to ensure that P1 / P2 ≤ 25%. The advantages of this invention are: maintaining stable operating sequence of each die component, improving product quality and production stability, increasing overall efficiency by over 80%, improving production cycle time, shortening the die debugging cycle, reducing production and debugging costs, and increasing production efficiency; simultaneously, it protects the press from excessive load impact from the die, ensuring press accuracy, and solving the problems of difficult debugging and poor production stability of double-action and triple-action dies on single-action presses.

Description

Technical Field

[0001] This invention relates to the field of stamping die technology, and more specifically, to a stamping method for stable production using multi-action dies on a single-action press. Background Technology

[0002] With the development of the automotive industry, there is an increasing pursuit of low cost and high efficiency. Currently, considering factors such as press cost and cycle time, single-action presses are commonly used for stamping die production. However, due to automotive styling requirements, the use of double-action and triple-action dies cannot be avoided. This results in a large number of double-action and triple-action dies having to be debugged and produced on single-action presses, with nitrogen cylinders installed inside the dies to replace the double-action function of the single-action press for auxiliary material pressing. However, in actual debugging and production, stability is poor, part quality and production efficiency fluctuate greatly, and the debugging cycle is long. Another problem exists: the impact of the air cushion on the die on the lower stretching pad of the press is significant, which can easily cause changes in the accuracy of the air cushion guide rail, thus affecting the production quality of all dies on this press line.

[0003] To address the aforementioned issues, the applicant implemented measures such as optimizing the coloring of the blank holder surface, welding the draw beads, enlarging the product's rounded corners, and adjusting the overall pressure, but none of these measures completely resolved the problem.

[0004] Invention Patent Content

[0005] To solve the above-mentioned technical problems, the present invention provides a stamping method for stable production using multi-action dies on a single-action press, wherein the pressure P1 of the nitrogen cylinder is set to 25% or less of the pressure P2 of the lower air cushion to maintain the working sequence of each component of the die.

[0006] The present invention solves the technical problem by adopting the following technical solution:

[0007] A stamping method for stable production using multi-action dies on a single-action press, wherein the multi-action die includes a matching upper die and a lower die, the upper die includes an upper die base, an upper pressure ring, and a punch, an upper air cushion is provided inside the upper pressure ring, and the upper pressure ring is connected to the upper air cushion; the lower die includes a lower die base, a lower pressure ring, and a die; the single-action press includes a slide block and a worktable, the worktable has a lower air cushion, and a plurality of lower air cushion support rods are connected to the lower air cushion;

[0008] The specific method is as follows:

[0009] S100. Fix the upper die base to the slider of the single-action press; fix the lower die base to the worktable of the single-action press, so that the lower pressure edge ring is connected to the lower air cushion support rod.

[0010] S200, Adjust the pressure P1 of the upper air cushion and / or the pressure P2 of the lower air cushion so that P1 / P2≤25%;

[0011] S300. Place the sheet metal on the lower die and stamp the part, specifically:

[0012] S301. Start the lower air cushion drive mechanism to make the lower air cushion support rod lift the lower pressure edge ring;

[0013] S302. Start the slider drive mechanism to make the slider move downward, which drives the upper die to move downward, so that the upper pressure ring abuts against the sheet metal; under the pressure of the lower pressure ring, the upper pressure ring moves upward.

[0014] S303, the slider moves further downward, causing the lower pressure ring to move downward under the action of the upper die, so that the punch and die close together to form the part.

[0015] Furthermore, the method also includes adjusting the pressure P1 of the upper air cushion and the pressure P2 of the lower air cushion to the theoretical simulation value P01 and the pressure P2 of the lower air cushion to the theoretical simulation value P02 when initially adjusting the pressure P1 of the upper air cushion and the pressure P2 of the lower air cushion, so that the mold can be actually debugged according to the theoretical simulation value, making the debugging process simpler.

[0016] Furthermore, the method also includes fine-tuning the pressure P1 of the upper air cushion and the pressure P2 of the lower air cushion, so that P1 / P2 < P01 / P02.

[0017] Furthermore, the upper and lower pressure rings are guided up and down by guide plates. The guide gap of the guide plates is no more than 0.05mm, so that the pressure surfaces of the upper and lower pressure rings remain parallel when they move up and down, thus avoiding shaking.

[0018] Furthermore, the method also includes adjusting the gap between the pressing surfaces of the upper and lower pressing rings using a coloring method, specifically:

[0019] S01. Apply colored oil to the sheet metal;

[0020] S02. Place the sheet metal on the lower die for stamping according to steps S100-S300;

[0021] S03. After stamping, check the color change of the oil on the parts of the sheet metal. When the color change rate of the oil on the parts of the sheet metal is greater than or equal to 80%, the gap of the blanking surface is qualified; when the color change rate of the oil on the parts is less than 80%, the gap of the blanking surface is unqualified.

[0022] S04. When the gap between the blanking surfaces is not up to standard, the upper and / or lower dies shall be adjusted and repaired, and then the discoloration rate of the oil on the parts of the sheet metal shall be tested according to steps S01-S03 until the gap between the blanking surfaces is up to standard.

[0023] Furthermore, the colored oil is either blue or red, which makes it easier to observe the coloring process.

[0024] Furthermore, the upper air cushion includes multiple nitrogen cylinders arranged circumferentially along the upper pressure ring. The upper pressure ring is connected to the push rod of the nitrogen cylinder, so that the upper pressure ring is subjected to balanced force and operates stably.

[0025] Furthermore, multiple nitrogen cylinders are connected in series via pipelines, with pressure gauges installed on the pipelines to facilitate observation of the pressure status of the nitrogen cylinders.

[0026] Furthermore, when using computer simulation to design the multi-movement mold, the pressure P1 of the upper air cushion is set to the theoretical simulation value P01, and the pressure P2 of the lower air cushion is set to the theoretical simulation value P02, with P01 / P02≤25%, so that the theoretical basis of the mold matches the actual debugging, providing sufficient debugging space for the later mold debugging, greatly shortening the time required for mold debugging and stabilization, and shortening the overall mold debugging cycle.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] (1) During the production process, the working sequence of each component of the mold is stable, which improves product quality and production stability, increases overall efficiency by more than 80%, improves production cycle, shortens mold debugging cycle, reduces production and debugging costs, and improves production efficiency; at the same time, it protects the press from excessive load impact of the mold, ensures the accuracy of the press, and solves the problems of difficult debugging and poor production stability of double-action and triple-action molds on single-action presses.

[0029] (2) This method can be applied to the early design of molds as a supplementary condition for process design. By setting a reasonable pressure ratio, the theoretical basis of the mold can be matched with the actual debugging, providing sufficient debugging space for the later mold debugging. It has high guiding value for both the actual production debugging of molds and the early development of new molds. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the upper mold structure of the present invention.

[0031] Figure 2 This is a schematic diagram of the lower mold structure of the present invention.

[0032] Figure 3 This is a schematic diagram of the air cushion structure of the present invention.

[0033] Figure 4 This is a schematic diagram of the stamping structure of the present invention.

[0034] In the diagram: 1-Upper mold; 11-Upper mold base; 12-Upper pressure ring; 13-Punch; 14-Upper air cushion; 141-Nitrogen cylinder; 142-Guide plate; 2-Lower mold; 21-Lower mold base; 22-Lower pressure ring; 23-Die; 24-Lower air cushion. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0036] This invention provides a stamping method for stable production using multi-moving dies on a single-moving press, wherein the multi-moving die includes a matching upper die 1 and a lower die 2, as shown in the reference. Figures 1-4 As shown, the upper mold 1 includes an upper mold base 11, an upper pressure ring 12, and a punch 13. An upper air cushion 14 is provided on the inner side of the upper pressure ring 12, and the upper pressure ring 12 is connected to the upper air cushion 14. The lower mold 2 includes a lower mold base 21, a lower pressure ring 22, and a die 23. The single-action press includes a slider and a worktable. The worktable has a lower air cushion 24, and multiple lower air cushion 24 support rods are connected to the lower air cushion 24.

[0037] The specific method is as follows:

[0038] S100. Fix the upper mold base 11 to the slider of the single-action press; fix the lower mold base 21 to the worktable of the single-action press, so that the lower pressure edge ring 22 is connected to the lower air cushion 24 support rod.

[0039] S200, Adjust the pressure P1 of the upper air cushion 14 and / or the pressure P2 of the lower air cushion 24 so that P1 / P2≤25%;

[0040] S300. Place the sheet metal on the lower die 2 and stamp the part, specifically:

[0041] S301. Start the lower air cushion 24 drive mechanism to make the lower air cushion 24 support rod lift the lower pressure ring 22;

[0042] S302. Start the slider drive mechanism to make the slider move downward, which drives the upper mold 1 to move downward, so that the upper pressure ring 12 abuts against the sheet metal; under the pressure of the lower pressure ring 22, the upper pressure ring 12 moves upward.

[0043] S303, the slider moves further downward, causing the lower pressure ring 22 to move downward under the action of the upper mold 1, so that the punch 13 and the die 23 close together to form the part.

[0044] During production, a multi-action die is installed on a single-action press. The multi-action die includes double-action and triple-action dies. Then, the pressure P1 of the upper air cushion 14 and / or the pressure P2 of the lower air cushion 24 are adjusted to a suitable value, ensuring that the pressure ratio P1 / P2 is ≤25%. For example, the pressure P1 of the upper air cushion 14 and the pressure P2 of the lower air cushion 24 are adjusted to a pressure ratio of 25%, 24%, 23%, 22%, 21%, 20%, etc., before stamping the sheet metal. (Reference) Figure 4As shown, during stamping, the upper pressure ring 12 is lifted by the upper air cushion 14, and the driving mechanism (such as a hydraulic cylinder) of the lower air cushion 24 drives the lower air cushion 24 to rise, causing the lower air cushion 24 support rod to lift the lower pressure ring 22, placing the sheet metal on the lower pressure ring 22 of the lower die 2; the slider of the single-action press is driven downward by the slider driving mechanism (such as a servo motor), which drives the upper die downward, causing the upper pressure ring 12 to move downward and press the sheet metal, and the lower pressure ring 22 pushes the upper pressure ring 12 back until the upper pressure ring 12 moves upward to the bottom and stops moving; the slider continues to move downward, and the upper die 1 pushes the lower pressure ring 22 back again until the punch 13 and the die 23 contact and close the mold to form the part.

[0045] Preferably, refer to Figure 2 and Figure 3 As shown, the upper air cushion 14 includes multiple nitrogen cylinders 141 arranged circumferentially along the upper pressure ring 12. The upper pressure ring 12 is connected to the push rod of the nitrogen cylinder 141, ensuring that the upper pressure ring 12 is subjected to balanced force and operates stably. The multiple nitrogen cylinders 141 are connected in series through pipelines, and pressure gauges are installed on the pipelines to facilitate observation of the pressure status of the nitrogen cylinders 141, and further to observe the pressure rise of the upper air cushion 14 at the moment of contact between the upper air cushion 14 and the lower air cushion 24.

[0046] A suitable pressure P2 for the lower air cushion 24 is sufficient to meet the molding requirements of the part. If P2 is too high, it may cause the part to tear; if P2 is too low, it may cause the part to wrinkle. Similarly, a suitable pressure P1 for the upper air cushion 14 is sufficient to meet the internal molding requirements of the part. If P1 is too high, it may also cause internal tearing; if P1 is too low, it may result in insufficient internal molding, leading to insufficient rigidity and excessive springback in the part. However, there is an interaction between the upper air cushion 14 and the lower air cushion 24 during mold operation. The pressure of the upper air cushion 14 is affected by many factors. First, the pressure of the upper air cushion 14 is provided by the nitrogen cylinder 141, but the actual pressure value of the nitrogen cylinder 141 changes significantly during the compression process, especially at the moment of contact between the upper air cushion 14 and the lower air cushion 24, sometimes reaching about twice the theoretical pressure value. Second, when the production cycle of the mold increases, the contact speed between the upper air cushion 14 and the lower air cushion 24 increases, and the impact force at contact increases, thus causing the pressure value of the nitrogen cylinder 141 to rise. The mold's process design includes a working sequence diagram for each component. Theoretically, when the mold is closed, the upper air cushion 14 should be compressed first, followed by the lower air cushion 24. To ensure the correct sequence of mold actions, the pressure of the upper air cushion 14 should be less than that of the lower air cushion 24. Furthermore, considering the inertia during the movement, the pressure P1 of the upper air cushion 14 should not exceed 50% of the pressure P2 of the lower air cushion 24. When adjusting the pressure P1 of the upper air cushion 14 and the pressure P2 of the lower air cushion 24, ensuring that P1 / P2 ≤ 25% ensures that when the pressure of the upper air cushion 14 increases instantaneously at the moment of contact with the lower air cushion 24, the pressure P1 of the upper air cushion 14 is still less than the pressure P2 of the lower air cushion 24. More preferably, the pressure P1 of the upper air cushion 14 is less than 50% of the pressure P2 of the lower air cushion 24. This ensures that the working sequence of each component of the mold remains unchanged, reduces the impact on the equipment, maintains the stability of the part quality, and improves the adaptability margin of the mold in long-term mass production. This also prevents the working sequence of the upper air cushion 14 and the lower air cushion 24 from changing during the mold closing process and causing changes in the part forming mechanism when the pressure on the lower air cushion 24 exceeds the set value of the lower air cushion 24.

[0047] When initially adjusting the pressure P1 of the upper air cushion 14 and the pressure P2 of the lower air cushion 24, the pressure P1 of the upper air cushion 14 can be adjusted to the theoretical simulation value P01 and the pressure P2 of the lower air cushion 24 can be adjusted to the theoretical simulation value P02, so that the pressure ratio P1 / P2 of the two is consistent with the pressure ratio P01 / P02 of the theoretical simulation value set during mold development simulation. The sheet metal is stamped according to steps S100-S300, and the quality of the part is observed to be stable. If the quality of the part is stable, the pressure P1 of the upper air cushion 14 is kept at the theoretical simulation value P01 and the pressure P2 of the lower air cushion 24 is kept at the theoretical simulation value P02 for stable production. If the quality of the part fluctuates, the pressure P1 of the upper air cushion 14 and the pressure P2 of the lower air cushion 24 are finely adjusted. The pressure P1 of the upper air cushion 14 is reduced, or the pressure P2 of the lower air cushion 24 is increased, or the pressure P1 of the upper air cushion 14 is reduced and the pressure P2 of the lower air cushion 24 is increased at the same time, thereby reducing the pressure ratio P1 / P2 so that P1 / P2 < P01 / P02. Actual debugging is carried out based on theoretical simulation values. The debugging process is guided by theoretical simulation values, making the debugging process simpler and saving debugging time.

[0048] During mold development simulation, computer simulation is used to design the multi-movement mold. The pressure P1 of the upper air cushion 14 is set as the theoretical simulation value P01, and the pressure P2 of the lower air cushion 24 is set as the theoretical simulation value P02, with P01 / P02 ≤ 25%. By setting a reasonable pressure ratio P01 / P02, the required pressure ratio of the upper air cushion 14 and the lower air cushion 24 can be used as a supplementary condition for mold process design, improving the process and design in the early stages of mold development. It also allows the theoretical basis of the mold to match actual debugging, providing sufficient debugging space for later mold debugging. Through computer simulation, multiple sets of theoretical simulation values ​​P01 and P02 can be set while keeping P01 / P02 ≤ 25% to find the optimal values ​​that meet the stamping process. These values ​​can then be applied to actual mold debugging, greatly shortening the time required for mold debugging and stabilization, and shortening the overall mold debugging cycle.

[0049] In actual production, factors such as the matching of the upper air cushion 14 guide with the lower air cushion 24 guide, the uniformity of coloring of the upper and lower pressure rings 12 and 22 of the die, and the parallelism between the upper pressure ring 12 and the bottom surface will all cause changes in the pressure borne by the lower air cushion 24. During stamping, the upper and lower pressure rings 12 and 22 move up and down guided by the guide plate 142. In order to keep the pressing surfaces parallel and prevent wobbling when the upper and lower pressure rings 12 and 22 move up and down, the guide gap of the guide plate 142 is no more than 0.05mm.

[0050] The method further includes adjusting the gap between the pressing surfaces of the upper pressing ring 12 and the lower pressing ring 22 using a coloring method, specifically:

[0051] S01. Apply colored oil to the sheet metal;

[0052] S02. Place the sheet metal on the lower die 2 for stamping according to steps S100-S300;

[0053] S03. After stamping, check the color change of the oil on the parts of the sheet metal. When the color change rate of the oil on the parts of the sheet metal is greater than or equal to 80%, the gap of the blanking surface is qualified; when the color change rate of the oil on the parts is less than 80%, the gap of the blanking surface is unqualified.

[0054] S04. When the gap between the pressing surfaces is not up to standard, the upper die 1 and / or the lower die 2 shall be adjusted and repaired, and then the discoloration rate of the oil on the parts of the sheet metal shall be tested according to steps S01-S03 until the gap between the pressing surfaces is up to standard.

[0055] A coloring method can be used to adjust and refine the upper die 1 and / or lower die 2, ensuring that the gap between the pressing surfaces of the upper pressing ring 12 and the lower pressing ring 22 is no greater than the thickness of the sheet metal. First, the sheet metal is coated with a colored oil, preferably blue or red, for easy observation of the coloring. Then, following steps S100-S300, the oil-coated sheet metal is placed on the lower die 2 for stamping. When adjusting the gap between the pressing surfaces, the pressure P1 of the upper air cushion 14 is maintained at no more than 25% of the pressure P2 of the lower air cushion 24. After stamping, the color of the oil on the pressed parts of the sheet metal will change. The color change of the oil on the pressed parts is checked. When the color change rate of the oil on the pressed parts is greater than or equal to 80%, the gap between the pressing surfaces is acceptable; when the color change rate of the oil on the pressed parts is less than 80%, the gap between the pressing surfaces is unacceptable. When the gap between the blanking surfaces is not up to standard, the mold needs to be repaired. The upper mold 1 or the lower mold 2 needs to be repaired or adjusted as needed, or both the upper mold 1 and the lower mold 2 need to be repaired or adjusted at the same time. Then, the color change rate of the part of the sheet metal is tested by coloring method according to steps S01-S03 until the gap between the blanking surfaces is up to standard.

[0056] Before adjusting the pressure P1 of the upper air cushion 14 to be less than 25% of the pressure P2 of the lower air cushion 24, a total of 11 production batches were carried out, with 6 batches experiencing quality fluctuations. The stabilization period was less than 2 batches, and the average downtime was 21.2 minutes per thousand pieces. After the ratio was adjusted, 5 production batches were carried out, and no quality instability issues occurred. There were only regular downtimes, averaging 2.6 minutes per thousand pieces, and no downtime due to quality fluctuations occurred. Production efficiency increased by about 88%.

[0057] In the description of this invention, it should be noted that the term "and / or" when used to list two or more items means that it can take any one of the listed items, or any combination of two or more of the listed items.

[0058] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A stamping method for stable production using multi-action dies on a single-action press, characterized in that, The multi-action mold includes a matching upper mold and a lower mold. The upper mold includes an upper mold base, an upper pressure ring, and a punch. An upper air cushion is provided inside the upper pressure ring, and the upper pressure ring is connected to the upper air cushion. The lower mold includes a lower mold base, a lower pressure ring, and a die. The single-action press includes a slider and a worktable. The worktable has a lower air cushion, and multiple lower air cushion support rods are connected to the lower air cushion. The specific method is as follows: S100. Fix the upper die base to the slider of the single-action press; fix the lower die base to the worktable of the single-action press, so that the lower pressure edge ring is connected to the lower air cushion support rod. S200, Adjust the pressure P1 of the upper air cushion and / or the pressure P2 of the lower air cushion so that P1 / P2≤25%; S300. Place the sheet metal on the lower die and stamp the part, specifically: S301. Start the lower air cushion drive mechanism to make the lower air cushion support rod lift the lower pressure edge ring; S302. Start the slider drive mechanism to make the slider move downward, which drives the upper die to move downward, so that the upper pressure ring abuts against the sheet metal; under the pressure of the lower pressure ring, the upper pressure ring moves upward. S303, the slider moves further downward, causing the lower pressure ring to move downward under the action of the upper die, so that the punch and die close together to form the part.

2. The stamping method for stable production using multi-action dies on a single-action press according to claim 1, characterized in that, The method also includes adjusting the pressure P1 of the upper air cushion and the pressure P2 of the lower air cushion to the theoretical simulation value P01 and the pressure P2 of the lower air cushion to the theoretical simulation value P02 when initially adjusting the pressure P1 of the upper air cushion and the pressure P2 of the lower air cushion.

3. The stamping method for stable production using multi-moving dies on a single-moving press according to claim 2, characterized in that, The method also includes fine-tuning the pressure P1 of the upper air cushion and the pressure P2 of the lower air cushion so that P1 / P2 < P01 / P02.

4. The stamping method for stable production using multi-moving dies on a single-moving press according to claim 1, characterized in that, The upper and lower pressure rings move up and down guided by guide plates, with a guide gap of no more than 0.05mm.

5. The stamping method for stable production using multi-action dies on a single-action press according to claim 1, characterized in that, The method also includes adjusting the gap between the pressing surfaces of the upper and lower pressing rings using a coloring method, specifically: S01. Apply colored oil to the sheet metal; S02. Place the sheet metal on the lower die for stamping according to steps S100-S300; S03. After stamping, check the color change of the oil on the parts of the sheet metal. When the color change rate of the oil on the parts of the sheet metal is greater than or equal to 80%, the gap of the blanking surface is qualified; when the color change rate of the oil on the parts is less than 80%, the gap of the blanking surface is unqualified. S04. When the gap between the blanking surfaces is not up to standard, the upper and / or lower dies shall be adjusted and repaired, and then the discoloration rate of the oil on the parts of the sheet metal shall be tested according to steps S01-S03 until the gap between the blanking surfaces is up to standard.

6. The stamping method for stable production using multi-action dies on a single-action press according to claim 5, characterized in that, The colored oil is blue or red.

7. The stamping method for stable production using multi-action dies on a single-action press according to claim 1, characterized in that, The upper air cushion includes multiple nitrogen cylinders arranged circumferentially along the upper pressure ring, and the upper pressure ring is connected to the push rod of the nitrogen cylinder.

8. The stamping method for stable production using multi-action dies on a single-action press according to claim 7, characterized in that, Multiple nitrogen cylinders are connected in series via pipelines, and pressure gauges are installed on the pipelines.

9. The stamping method for stable production using multi-moving dies on a single-moving press according to claim 1 or 2, characterized in that, When using computer simulation to design the multi-movement mold, the pressure P1 of the upper air cushion is set to the theoretical simulation value P01, the pressure P2 of the lower air cushion is set to the theoretical simulation value P02, and P01 / P02≤25%.

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