A method for forming a convex thin sheet stainless steel part

Abstract

This invention discloses a forming method for corrugated stainless steel parts with convex thin plates. The forming method includes mold mounting, pre-forming by stamping, stamping forming, and shearing correction. Using the forming method described in this invention, existing punch presses are utilized. During the stamping process, a rubber pad is added to the existing mold, and multiple stamping operations are employed. Utilizing the principle of rubber expansion and contraction, the flow of material during the forming process can be effectively controlled. This ensures uniform material flow under forming force, thereby preventing wrinkling of the parts. This method not only effectively solves the technical problem of wrinkling easily at the perimeter of the corrugated area but also improves forming efficiency, thereby increasing the pass rate of formed parts, ensuring product quality, and significantly reducing processing costs. It can be applied to the processing of easily wrinkled parts, is easy to operate, and is suitable for widespread application.

Description

Technical Field

[0001] This invention relates to the field of sheet metal forming technology, specifically to a forming method for corrugated stainless steel parts made of convex thin sheet. Background Technology

[0002] In the sheet metal forming process, in addition to structurally regular parts, irregularly shaped structural parts are frequently encountered, such as... Figures 1 to 4 The convex, corrugated stainless steel part shown is only 0.3mm thick. The part has a certain curvature and is an irregular, non-standard structural component. Based on strength requirements, numerous densely arranged reinforcing ribs are designed on its surface. When forming this type of part using existing stamping processes, due to the dense internal reinforcing ribs and the thin material, the material in the reinforcing rib area tends to shrink drastically towards the center during stamping, while the material outside the reinforcing rib area flows excessively. This causes tangential strain at the junction of the reinforcing rib area and the edge of the part, and wrinkling along the edges of the reinforcing ribs, resulting in a decrease in part quality and even scrapping of the finished product. Therefore, to meet the processing requirements of this type of part, existing stamping methods need to be improved. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the problems existing in the background art by providing a convenient forming method. Using this forming method, by adding a rubber pad to the existing mold and adopting a multiple stamping process, the material around the edge of the reinforcing rib is prevented from shrinking and wrinkling, thereby improving processing efficiency and product quality and reducing processing costs. Specifically, it is a forming method for corrugated stainless steel parts with convex thin plates.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: a forming method for corrugated stainless steel parts with convex thin plates, characterized in that: the forming method includes mold mounting, pre-forming by stamping, stamping forming, and shearing correction, specifically including the following steps:

[0005] (1) Install the mold. First, install the mold on the punch press workbench. The upper mold is a concave mold made of lead alloy, while the lower mold is a convex mold made of cast steel. Then, after the mold is opened, a rubber pad is placed on the convex mold on the upper surface of the lower mold. Finally, the stainless steel blank to be formed is placed on the rubber pad.

[0006] (2) Stamping preforming: In the stamping preforming process, the closing gap between the upper and lower dies in the mold should be finely adjusted so that when the upper and lower dies close during the stamping process, there is a certain closing gap between the upper and lower dies so that the upper and lower dies cannot be completely fitted together and leave a rubber buffer expansion allowance. Then, under the action of the stamping press, the stainless steel blank is stamped and preformed using the upper die made of lead alloy and the lower die made of cast steel to obtain a semi-finished product.

[0007] (3) Stamping: In the stamping process, the mold installed on the press workbench is replaced in advance. The upper mold is made of epoxy resin and replaced with the upper mold made of lead alloy. Then, the closing gap between the upper and lower molds in the mold is finely adjusted so that when the upper and lower molds are closed during the stamping process, the upper and lower molds can fit together completely without any closing gap. Then, paper tape is used to stick inside the upper mold. The bonding part corresponds to the wrinkle-prone part in the semi-finished product. Finally, under the action of the press, the upper mold made of epoxy resin and the lower mold made of cast steel are used to stamp the semi-finished product to obtain the stamped finished product.

[0008] (4) Shearing and correction: the stamped product obtained after stamping is sheared according to the design requirements, and the part is locally corrected and shaped to obtain the finished part.

[0009] Furthermore, the forming method for corrugated stainless steel parts with convex thin plates according to the present invention is characterized in that: during the mold assembly process in step (1), the rubber pad is made of polyurethane soft rubber with a thickness of 5mm, and the rubber pad is required to cover the entire working surface of the lower mold and the area outside the working surface.

[0010] Furthermore, in the forming method for corrugated stainless steel parts with convex thin plates described in this invention, during the stamping pre-forming process in step (2), the specific method for finely adjusting the closing gap between the upper and lower dies in the mold is to adjust the upper die upward so that the closing gap between the upper and lower dies is 2-3 mm, thereby leaving a rubber buffer allowance so that the upper and lower dies cannot be completely fitted together.

[0011] Furthermore, in the forming method for corrugated stainless steel parts with convex thin plates described in this invention, during the stamping process in step (3), the degree and position of wrinkling are predicted according to the shape and structure of the semi-finished product, and 1 to 3 layers of paper tape are bonded to the corresponding position in the upper mold.

[0012] Furthermore, in the forming method for corrugated stainless steel parts with convex thin plates according to the present invention, the punch press is a 400-630 ton hydraulic punch press, the punch press worktable includes an upper worktable and a lower worktable, the upper die of the mold is installed under the upper worktable, and the lower die is installed on the lower worktable.

[0013] The forming method for corrugated stainless steel parts with convex thin plates, as described in this invention, offers several advantages over existing technologies. Firstly, by adding rubber pads to existing molds and employing multiple stamping processes using the elasticity of rubber during the forming process, the material flow can be effectively controlled. This ensures uniform material flow under forming force, preventing wrinkles in the parts. Secondly, compared to existing methods, this method largely eliminates the need for manual correction. Existing methods typically require approximately 40 minutes of manual correction per part. The improved method almost entirely eliminates manual correction; even minor imperfections are addressed with minimal, localized adjustments rather than extensive manual correction. This significantly improves forming efficiency and reduces labor costs.

[0014] Therefore, the forming method described in this invention can not only effectively solve the technical problem of wrinkling at the boundary of the corrugated area, but also improve its forming efficiency, thereby increasing the pass rate of part forming, ensuring product forming quality, and greatly reducing processing costs. It can be applied to the processing of easily wrinkled parts, and its operation is convenient and suitable for widespread application. Attached Figure Description

[0015] The present invention will now be described in further detail with reference to the accompanying drawings.

[0016] Figure 1 A three-dimensional structural diagram of a convex thin-plate corrugated stainless steel part;

[0017] Figure 2 for Figure 1 Main view;

[0018] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure along the AA direction;

[0019] Figure 4 for Figure 3 Enlarged schematic diagram of the local structure at point B.

[0020] Figure 5 A schematic diagram of an existing cast steel lower mold structure;

[0021] Figure 6 for Figure 5 A schematic diagram of the structure after the rubber pad is laid on the middle and lower mold;

[0022] Figure 7 A schematic diagram of the structure for bonding paper tape to an existing epoxy resin mold.

[0023] Figure 8Physical samples of products processed using the method described in this invention. Figure 1 ;

[0024] Figure 9 Physical samples of products processed using the method described in this invention. Figure 2 ;

[0025] Figure 10 The actual product after laying rubber pads on the existing lower mold. Figure 1 ;

[0026] Figure 11 The actual product after laying rubber pads on the existing lower mold. Figure 2 ;

[0027] Figure 12 The images show a comparison of physical products processed using existing methods and the method described in this invention. Detailed Implementation

[0028] To further illustrate the concept of the present invention, specific embodiments are described below to illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0029] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness or purpose of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, terms such as "above," "below," "front," and "back" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0030] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection" and "provided with" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0031] It should be noted that the term "comprising" or any other variation is 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.

[0032] like Figures 5 to 7 As shown, this embodiment provides a forming method for a corrugated stainless steel part with a thickness of 0.3 mm. The forming method includes mold mounting, pre-forming by stamping, stamping, and shearing correction, specifically including the following steps:

[0033] (1) Mold installation: Using an existing 630-ton hydraulic press as the power source, the mold is first installed on the press worktable. The upper mold is a concave mold made of lead alloy, while the lower mold is a convex mold made of cast steel. The upper mold is installed under the upper worktable, and the lower mold is installed on the lower worktable. Then, in the lower mold after mold opening, a 5mm thick polyurethane soft rubber is used as a rubber pad. The rubber pad is laid on the convex mold, and it is required that the rubber pad can cover the entire working surface of the lower mold and the area outside the working surface. Finally, a 0.3mm thick stainless steel blank to be formed is laid on the rubber pad. The actual picture after laying the rubber pad is shown below. Figure 10 and Figure 11 As shown;

[0034] (2) Stamping preforming: In the stamping preforming process, the closing gap between the upper and lower dies in the mold needs to be finely adjusted first. The specific fine adjustment method is to adjust the upper die upwards, and the closing gap between the upper die and the lower die should be 2-3mm. The purpose is to use the rubber pad to buffer the expansion effect, so that when the upper die made of lead alloy material and the lower die made of cast steel are used to stamp and preform stainless steel blanks, the upper and lower dies in the mold cannot be completely fitted. After finely adjusting the corresponding gap, the upper die is moved to the lower die direction under the action of the stamping press. Through the cooperation of the upper and lower dies, the semi-finished product after stamping preforming can be obtained.

[0035] (3) Stamping: In the stamping process, the mold installed on the press workbench is replaced in advance. The upper mold made of epoxy resin is replaced with the upper mold made of lead alloy. Then, the closing gap between the upper and lower molds in the mold is finely adjusted so that when the upper and lower molds in the mold are closed during the stamping process, the upper and lower molds can be completely fitted without any closing gap. Then, paper tape is used to bond to the upper mold. The bonding part corresponds to the wrinkle-prone part of the semi-finished product. Finally, under the action of the press, the upper mold made of epoxy resin and the lower mold made of cast steel are used to stamp the semi-finished product to obtain the stamped finished product. In the specific use, the bonding position and number of bonding layers of paper tape can be predicted according to the shape structure of the semi-finished product. The degree and position of wrinkling can be predicted. 1 to 3 layers of paper tape can be bonded to the corresponding position in the upper mold.

[0036] (4) Shearing and straightening: The stamped product obtained after stamping is sheared according to the design requirements, and the part is locally straightened and shaped to obtain the finished part, such as... Figure 8 and Figure 9 The image shown is a physical photograph of a product processed using the method described in this invention. Figure 12 The image shown is a comparison of the products processed using the existing method and the method described in this invention. The comparison shows that by using the method described in this invention, polyurethane rubber is used as a rubber pad, which is laid on the lower mold, and then pre-forming and stamping are performed, which can effectively avoid wrinkling problems.

[0037] The forming method described in this invention utilizes polyurethane rubber as a rubber pad during the preforming process. Taking advantage of the rubber pad's reaction force after compression under external force, pressure can be applied to the material surface, thus controlling the excessive material flow and achieving uniform material collection. Simultaneously, depending on the location and wrinkling degree of the reinforcing ribs, multiple layers of paper tape can be added to the upper mold. The bonded paper tape forms raised areas, which act as a buffer during stamping, reducing material flow during mold closing and controlling material flow during forming. This prevents tangential strain and wrinkling at the junction of the reinforcing ribs and surrounding areas.

[0038] In summary, the forming method described in this invention utilizes existing punch presses and adds rubber pads to the existing molds during the stamping process. By employing multiple stamping operations and leveraging the elasticity of rubber, the flow of material during the forming process can be effectively controlled. This ensures that the material flows uniformly under forming force, thereby preventing wrinkles in the parts. This method not only effectively solves the technical problem of wrinkling at the boundaries of corrugated areas but also improves forming efficiency, thereby increasing the pass rate of part forming, ensuring product quality, and significantly reducing processing costs. It can be applied to the processing of easily wrinkled parts, is easy to operate, and is suitable for widespread application.

[0039] Other aspects of this invention that are not detailed herein are all conventional techniques known to those skilled in the art.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. 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 forming method for corrugated stainless steel parts made of convex thin sheet, characterized in that: The forming method includes mold mounting, pre-forming by stamping, stamping, and shearing correction, specifically including the following steps: (1) Install the mold. First, install the mold on the punch press workbench. The upper mold is a concave mold, made of lead alloy. The lower mold is a convex mold, made of cast steel. Then, after the mold is opened, a rubber pad is placed on the convex mold on the upper surface of the lower mold. Finally, the stainless steel blank to be formed is placed on the rubber pad. (2) Stamping preforming: In the stamping preforming process, the closing gap between the upper and lower dies of the mold should be finely adjusted so that when the upper and lower dies of the mold are closed during the stamping process, there is a certain closing gap between the upper and lower dies so that the upper and lower dies cannot be completely fitted together and leave a rubber buffer margin. Then, under the action of the stamping press, the stainless steel blank is stamped and preformed using the upper die made of lead alloy and the lower die made of cast steel to obtain a semi-finished product. (3) Stamping: In the stamping process, the mold installed on the press workbench is replaced in advance. The upper mold is made of epoxy resin and replaced with the upper mold made of lead alloy. Then, the closing gap between the upper and lower molds in the mold is finely adjusted so that when the upper and lower molds are closed during the stamping process, the upper and lower molds can fit together completely without any closing gap. Then, paper tape is used to stick inside the upper mold. The bonding part corresponds to the wrinkle-prone part in the semi-finished product. Finally, under the action of the press, the upper mold made of epoxy resin and the lower mold made of cast steel are used to stamp the semi-finished product to obtain the stamped finished product. (4) Shearing and correction: the stamped product obtained after stamping is sheared according to the design requirements, and the part is locally corrected and shaped to obtain the finished part.

2. The forming method for corrugated stainless steel parts with convex thin plates according to claim 1, characterized in that: In the molding process of step (1), the rubber pad is made of 5mm thick polyurethane soft rubber, and the rubber pad is required to cover the entire working surface of the lower mold and the area outside the working surface.

3. The forming method for corrugated stainless steel parts with convex thin plates according to claim 1, characterized in that: In the step (2) of the stamping preforming process, the specific way to finely adjust the closing gap between the upper and lower dies in the mold is to adjust the upper die upward so that the closing gap between the upper and lower dies is 2-3mm, so that the upper and lower dies cannot be completely fitted together and leave a rubber buffer expansion allowance.

4. The forming method for corrugated stainless steel parts with convex thin plates according to claim 1, characterized in that: In the stamping process of step (3), based on the shape and structure of the semi-finished product, the degree and location of wrinkling are predicted, and 1 to 3 layers of paper tape are bonded to the corresponding position in the upper mold. The purpose is to reduce the mold gap in the parts of the part that are prone to wrinkling.

5. The forming method for corrugated stainless steel parts with convex thin plates according to claim 1, characterized in that: The punch press is a 400-630 ton hydraulic punch press. The punch press worktable includes an upper worktable and a lower worktable. The upper die of the mold is installed under the upper worktable, while its lower die is installed on the lower worktable.

Images