Stamping method for stable production on single-acting press by using multiple-acting die

Abstract

The invention provides a stamping method for stable production on a single-action press by using a multi-action die, which comprises the following steps of: adjusting the pressure P1 of an upper air cushion and / or the pressure P2 of a lower air cushion to ensure that P1 / P2 is less than or equal to 25%. The method has the advantages that the working time sequence of each component of the mold is kept stable, the product quality and the production stability are improved, the overall efficiency is improved by more than 80%, the production takt is improved, the mold debugging period is shortened, the production and debugging cost is reduced, and the production efficiency is improved; meanwhile, the pressing machine is protected against overhigh load impact of the mold, the precision of the pressing machine is guaranteed, and the problems that double-acting and triple-acting molds are difficult to debug on a single-acting pressing machine and the production stability is poor are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of stamping dies, and in particular to a stamping method for stable production using multi-action dies on a single-action press. Background Art

[0002] With the development of the automobile industry, low cost and high efficiency are increasingly pursued. At present, based on factors such as press cost and cycle time, single-action presses are generally used to produce stamping dies; and based on the requirements for automobile styling, the use of double-action and triple-action dies cannot be avoided. As a result, a large number of double-action and triple-action dies have to be debugged and produced on single-action presses, and nitrogen cylinders are set in the mold to replace the double-action function of the single-action press to assist in pressing. However, the actual debugging and production process has poor stability, large fluctuations in part quality and production efficiency, and a long debugging cycle. At the same time, there is another problem. Due to the large impact of the air cushion on the upper mold on the tensile pad under the press, it is easy to cause changes in the accuracy of the air cushion guide rail under the press, which in turn affects the production quality of all molds on this press line.

[0003] In order to solve the above problems, the applicant took measures such as optimizing the coloring of the pressing surface, welding of drawbeads, enlarging the product corner radius, and adjusting the overall pressure, but none of them completely solved the problem.

[0004] Invention patent content

[0005] In order to solve the above technical problems, the present invention provides a stamping method for stable production using a multi-action mold 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 mold.

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

[0007] A stamping method for stable production using a multi-action die on a single-action press, the multi-action die comprising an upper die and a lower die that match each other, the upper die comprising an upper die seat, an upper pressure ring and a punch, an upper air cushion is arranged inside the upper pressure ring, and the upper pressure ring is connected to the upper air cushion; the lower die comprises a lower die seat, a lower pressure ring and a concave die; the single-action press comprises a slide block and a workbench, the workbench 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:

[0009] S100, fixing the upper die seat to the slide block of the single-action press; fixing the lower die seat to the workbench of the single-action press, so that the lower pressure edge ring is connected to the lower air cushion support rod;

[0010] S200, adjusting 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, placing the sheet on the lower die and stamping the parts, specifically:

[0012] S301, starting the lower air cushion driving mechanism to enable the lower air cushion supporting rod to lift up the lower pressure edge ring;

[0013] S302, start the slider driving mechanism to make the slider move downward, drive the upper die to move downward, make the upper pressure ring abut against the sheet material; under the pressure of the lower pressure ring, make the upper pressure ring move upward;

[0014] S303, the slider moves further downward, so that the lower edge pressure ring moves downward under the action of the upper die, so that the punch and the die are closed until the part is formed.

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

[0016] Furthermore, the method further 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 edge pressing ring and the lower edge pressing ring are guided up and down by guide plates, and the guiding clearance of the guide plates is not greater than 0.05 mm, so that the pressing surfaces of the upper edge pressing ring and the lower edge pressing ring remain parallel when they move up and down to avoid shaking.

[0018] Furthermore, the method further comprises adjusting the gap between the upper blank holder and the lower blank holder by a coloring method, specifically:

[0019] S01, apply colored oil on the sheet;

[0020] S02, placing the sheet material on the lower die for stamping according to steps S100-S300;

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

[0022] S04. When the gap between the pressing surfaces is unqualified, the upper die and / or the lower die are debugged and repaired, and then the color change rate of the oil on the parts of the sheet is tested according to steps S01-S03 until the gap between the pressing surfaces is qualified.

[0023] Furthermore, the colored oil is blue oil or red oil, which is convenient for observing the coloring state.

[0024] Furthermore, the upper air cushion comprises a plurality of nitrogen cylinders arranged along the circumference of the upper pressure ring, and the upper pressure ring is connected to the top rods of the nitrogen cylinders, so that the upper pressure ring is subjected to balanced force and operates stably.

[0025] Furthermore, a plurality of nitrogen cylinders are connected in series through pipelines, and a pressure gauge is arranged on the pipeline to facilitate observation of the pressure state of the nitrogen cylinders.

[0026] Furthermore, when using computer simulation to design the multi-action 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, and 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 to stabilize, and shortening the mold debugging cycle as a whole.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

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

[0029] (2) This method can be applied to the early design of the mold as a supplementary condition for process design. By setting a reasonable pressure ratio, it ensures that the theoretical basis of the mold matches the actual debugging, providing sufficient debugging space for the later mold debugging. It has a high guiding value for both the actual production debugging of the mold and the early development of new molds. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

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

[0034] In the figure: 1-upper die; 11-upper die seat; 12-upper pressure ring; 13-punch; 14-upper air cushion; 141-nitrogen cylinder; 142-guide plate; 2-lower die; 21-lower die seat; 22-lower pressure ring; 23-die; 24-lower air cushion. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0036] The present invention provides a stamping method for stable production using a multi-action die on a single-action press, wherein the multi-action die comprises an upper die 1 and a lower die 2 that are matched with each other. Figure 1-Figure 4 As shown, the upper die 1 includes an upper die seat 11, an upper pressure ring 12 and a punch 13, an upper air cushion 14 is arranged inside the upper pressure ring 12, and the upper pressure ring 12 is connected to the upper air cushion 14; the lower die 2 includes a lower die seat 21, a lower pressure ring 22 and a concave die 23; the single-action press includes a slide block and a workbench, the workbench has a lower air cushion 24, and a plurality of lower air cushion 24 support rods are connected to the lower air cushion 24;

[0037] The specific method is:

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

[0039] S200, adjusting 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, placing the sheet material on the lower die 2, and stamping the parts, specifically:

[0041] S301, start the driving mechanism of the lower air cushion 24, so that the supporting rod of the lower air cushion 24 lifts up the lower pressure edge ring 22;

[0042] S302, start the slider driving mechanism to make the slider move downward, drive the upper die 1 to move downward, make the upper pressure ring 12 abut against the sheet material; under the pressure of the lower pressure ring 22, make the upper pressure ring 12 move upward;

[0043] S303, the slider moves further downward, so that the lower edge pressing ring 22 moves downward under the action of the upper die 1, so that the punch 13 and the die 23 are closed until the part is formed.

[0044] During production, the multi-action mold is installed on the single-action press. The multi-action mold includes a double-action mold and a triple-action mold. 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 size so that the pressure ratio P1 / P2 between the two 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 so that the pressure ratio P1 / P2 is 25%, 24%, 23%, 22%, 21%, 20%, etc., and then the sheet is punched. Figure 4As shown, during stamping, the upper pressure ring 12 is lifted up by the upper air cushion 14, and the driving mechanism of the lower air cushion 24 (such as a hydraulic cylinder) drives the lower air cushion 24 to rise, so that the support rod of the lower air cushion 24 lifts the lower pressure ring 22, and the sheet material is placed on the lower pressure ring 22 of the lower die 2; the slider of the single-acting press is driven downward by the slider driving mechanism (such as a servo motor), driving the upper die to move downward, so that the upper pressure ring 12 moves downward to press the sheet material, and the lower pressure ring 22 pushes the upper pressure ring 12 back until the upper pressure ring 12 runs upward to the bottom and stops running; 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 are in contact and the mold is closed to form the part.

[0045] Preferably, reference Figure 2 and Figure 3 As shown, the upper air cushion 14 includes a plurality of nitrogen cylinders 141 arranged along the circumference of the upper pressure ring 12. The upper pressure ring 12 is connected to the top rod of the nitrogen cylinder 141, so that the upper pressure ring 12 is subjected to balanced force and operates stably. The plurality of nitrogen cylinders 141 are connected in series through pipelines, and a pressure gauge is arranged on the pipeline, so that the pressure state of the nitrogen cylinder 141 can be conveniently observed, and the pressure increase of the upper air cushion 14 can be further observed when the upper air cushion 14 and the lower air cushion 24 are in contact.

[0046] The appropriate pressure P2 of the lower air cushion 24 can meet the molding requirements of the product. If P2 is too large, the product may be torn, and if P2 is too small, the product may be wrinkled; the appropriate pressure P1 of the upper air cushion 14 can meet the internal molding requirements of the product. If P1 is too large, it will also cause internal tearing of the product. If P1 is too small, it may cause insufficient internal molding of the product, which will lead to insufficient rigidity and large rebound of the product. However, there is interaction between the upper air cushion 14 and the lower air cushion 24 during the working process of the mold. The pressure of the upper air cushion 14 will be affected by many factors. First, the pressure of the upper air cushion 14 of the mold is provided by the nitrogen cylinder 141, but the actual pressure value of the nitrogen cylinder 141 changes greatly during the pressure process, especially the instantaneous pressure change of the upper air cushion 14 and the lower air cushion 24 is large, sometimes reaching about twice the theoretical pressure value. Second, when the tact of the mold production increases, the contact speed of the upper air cushion 14 and the lower air cushion 24 will increase, and the impact force will increase during contact, which will cause the pressure value of the nitrogen cylinder 141 to rise. When the mold is designed, a working timing diagram for each component of the mold is set. When the mold is closed, the theoretical requirement is that the upper air cushion 14 of the mold is compressed first, and the lower air cushion 24 of the press is compressed later. In order to ensure the sequence of mold movements, the set pressure of the upper air cushion 14 is required to be lower than the pressure of the lower air cushion 24. Considering the inertia during movement, the pressure P1 of the upper air cushion 14 is required to be no higher than 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, P1 / P2≤25%. This can ensure that when the pressure of the upper air cushion 14 instantly rises at the moment the upper air cushion 14 and the lower air cushion 24 come into contact, 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 can be 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, and thus maintains the stability of the quality of the product, improves the adaptability margin of the mold in the long-term mass production process, and avoids the situation where the pressure on the lower air cushion 24 is greater than the set value of the lower air cushion 24, causing the working sequence of the upper air cushion 14 and the lower air cushion 24 to change during the mold closing process, resulting in changes in the molding mechanism of the product.

[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 the mold development simulation, and the sheet is stamped according to steps S100-S300 to observe whether the quality of the part is 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 workpiece fluctuates, the pressure P1 of the upper air cushion 14 and the pressure P2 of the lower air cushion 24 are fine-tuned to reduce the pressure P1 of the upper air cushion 14, or increase the pressure P2 of the lower air cushion 24, or simultaneously reduce the pressure P1 of the upper air cushion 14 and increase the pressure P2 of the lower air cushion 24, thereby reducing the pressure ratio P1 / P2, so that P1 / P2<P01 / P02, and performing actual debugging based on the theoretical simulation values. The debugging process is guided by the theoretical simulation values, which makes the debugging process simpler and saves debugging time.

[0048] During the simulation of mold development, the multi-action mold is designed using computer simulation, and the pressure P1 of the upper air cushion 14 is set to the theoretical simulation value P01, and the pressure P2 of the lower air cushion 24 is set to the theoretical simulation value P02, and P01 / P02≤25%. By setting a reasonable pressure ratio P01 / P02, the pressure ratio requirements of the upper air cushion 14 and the lower air cushion 24 of the mold can be used as a supplementary condition for mold process design, improve the process and design of the early development of the mold, and match the theoretical basis of the mold with the actual debugging, providing sufficient debugging space for the later mold debugging. Through computer simulation, multiple sets of theoretical simulation values ​​P01 and P02 can be set while keeping P01 / P02≤25%, and the optimal values ​​that meet the stamping process can be found and applied to the actual debugging of the mold, which greatly shortens the time required for mold debugging and stabilization, and shortens the mold debugging cycle as a whole.

[0049] In the actual production process, the matching of the guide of the upper air cushion 14 and the guide of the lower air cushion 24 of the press, the uniformity of the coloring of the upper and lower pressure rings 12 and 22 of the mold, and the parallelism between the upper and lower pressure rings 12 and the bottom surface will cause changes in the pressure on the lower air cushion 24. During stamping, the upper and lower pressure rings 12 and 22 are guided by the guide plate 142 to move up and down. In order to keep the pressure surfaces parallel and without shaking when the upper and lower pressure rings 12 and 22 move up and down, the guide clearance of the guide plate 142 is not greater than 0.05mm.

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

[0051] S01, apply colored oil on the sheet;

[0052] S02, placing the sheet material on the lower die 2 for stamping according to steps S100-S300;

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

[0054] S04. When the gap between the pressing surfaces is unqualified, the upper die 1 and / or the lower die 2 are debugged and repaired, and then the color change rate of the oil in the parts of the sheet is tested according to steps S01-S03 until the gap between the pressing surfaces is qualified.

[0055] The coloring method can be used to debug and repair the upper die 1 and / or the lower die 2 so that the gap between the upper pressure ring 12 and the lower pressure ring 22 is not greater than the thickness of the sheet material. First, the sheet material is fully coated with colored oil. Preferably, blue oil or red oil is used to facilitate observation of the coloring state. Then, according to steps S100-S300, the sheet material coated with oil is placed on the lower die 2 for stamping. When adjusting the gap between the pressure surfaces, the pressure P1 of the upper air cushion 14 is still 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 part of the sheet material that is pressed will change. Check the color change of the oil on the part. When the color change rate of the oil on the part is greater than or equal to 80%, the gap between the pressure surfaces is qualified; when the color change rate of the oil on the part is less than 80%, the gap between the pressure surfaces is unqualified. When the gap between the pressing surfaces is unqualified, the mold needs to be repaired. The upper mold 1 or the lower mold 2 can be debugged and repaired as needed, or both the upper mold 1 and the lower mold 2 can be debugged and repaired at the same time. Then, the color change rate of the parts of the sheet metal is detected using the coloring method according to steps S01-S03 until the gap between the pressing surfaces is qualified.

[0056] Before adjusting the pressure P1 of the upper air cushion 14 ≤ 25% of the pressure P2 of the lower air cushion 24, a total of 11 batches of production were carried out, 6 batches showed quality fluctuations, the stable period was less than 2 batches, and the average shutdown time was 21.2 minutes per thousand pieces; after the ratio was adjusted, 5 batches of production were carried out, and no quality instability problems occurred. There was only routine shutdown time of an average of 2.6 minutes per thousand pieces, and there was no shutdown due to quality fluctuations. The production efficiency was improved by about 88%.

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

[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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A stamping method for stable production using a multi-action die on a single-action press, characterized in that: The multi-action mold includes an upper mold and a lower mold that are matched, the upper mold includes an upper mold base, an upper pressure ring and a punch, an upper air cushion is arranged on the inner side of 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 concave mold; the single-action press includes a slide block and a workbench, the workbench has a lower air cushion, and a plurality of lower air cushion support rods are connected to the lower air cushion; The specific method is: S100, fixing the upper die seat to the slide block of the single-action press; fixing the lower die seat to the workbench of the single-action press, so that the lower pressure edge ring is connected to the lower air cushion support rod; S200, adjusting the pressure P1 of the upper air cushion and / or the pressure P2 of the lower air cushion so that P1 / P2≤25%; S300, placing the sheet on the lower die and stamping the parts, specifically: S301, starting the lower air cushion driving mechanism to enable the lower air cushion supporting rod to lift up the lower pressure edge ring; S302, start the slider driving mechanism to make the slider move downward, drive the upper die to move downward, make the upper pressure ring abut against the sheet material; under the pressure of the lower pressure ring, make the upper pressure ring move upward; S303, the slider moves further downward, so that the lower edge pressure ring moves downward under the action of the upper die, so that the punch and the die are closed until the part is formed.

2. The punching method for stable production using a multi-action die on a single-action press according to claim 1, characterized in that: The method further comprises initially adjusting the pressure P1 of the upper air cushion and the pressure P2 of the lower air cushion, wherein the pressure P1 of the upper air cushion is adjusted to a theoretical simulation value P01 and the pressure P2 of the lower air cushion is adjusted to a theoretical simulation value P02.

3. The punching method for stable production using a multi-action die on a single-action press according to claim 2, characterized in that: The method further includes finely adjusting 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 punching method for stable production using a multi-action die on a single-action press according to claim 1, characterized in that: The upper pressure ring and the lower pressure ring are guided up and down by the guide plate, and the guide clearance of the guide plate is not more than 0.05mm.

5. The punching method for stable production using a multi-action die on a single-action press according to claim 1, characterized in that: The method further includes adjusting the gap between the upper and lower blank holders by a coloring method, specifically: S01, apply colored oil on the sheet; S02, placing the sheet material on the lower die for stamping according to steps S100-S300; S03. After stamping is completed, check the color change of the oil on the parts of the sheet. When the color change rate of the oil on the parts of the sheet is greater than or equal to 80%, the gap between the pressing surfaces is qualified; when the color change rate of the oil on the parts is less than 80%, the gap between the pressing surfaces is unqualified. S04. When the gap between the pressing surfaces is unqualified, the upper die and / or the lower die are debugged and repaired, and then the color change rate of the oil on the parts of the sheet is tested according to steps S01-S03 until the gap between the pressing surfaces is qualified.

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

7. The punching method for stable production using a multi-action die on a single-action press according to claim 1, characterized in that: The upper air cushion comprises a plurality of nitrogen cylinders arranged along the circumference of the upper pressure ring, and the upper pressure ring is connected to the top rods of the nitrogen cylinders.

8. The punching method for stable production using a multi-action die on a single-action press according to claim 7, characterized in that: Multiple nitrogen cylinders are connected in series through pipelines, and pressure gauges are set on the pipelines.

9. The punching method for stable production using a multi-action die on a single-action press according to claim 1 or 2, characterized in that: When the multi-action mold is designed by computer simulation, 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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