Forming processes can be performed using various forming conditions such as, for example, a mold shape, a lubricating condition, a forming speed, a blank-holder force, a temperature of a mold and a material to be press-formed. Conventionally, such conditions may be defined in advance for a particular material based on, e.g., a prior similar procedure, an experimental production, a process simulation using a finite element method, or the like. This approach can be used for metallic materials undergoing, e.g., a deep-drawing process, a bending process, a cutting process, and the like, using a press-forming device.
However, various metallic materials which may be used as, e.g., a plate material, a pipe material, a bar material, a wire material, a granular material, and so on, can be obtained from a raw material and/or a scrap material passing through several processes such as, e.g., melting, smelting, molding, rolling, heat treatment and/or a secondary pressing process. Consequently, a certain degree of variation may exist in mechanical properties of a formed product arising from variations in process conditions resulting from, e.g., a variation of chemical components, a nonuniformity of temperature, and so on. Accordingly, undesirable forming results may occur because formability may vary in different portions of the material or throughout a production lot, even if adequate forming conditions are defined in advance as described above. Quality control in a material manufacturing process can be performed more rigorously to help avoid such undesirable forming behavior. However, excessive quality control requirements may cause an increase in material cost, and thus may not be preferable.
Poor forming behavior may also occur because of environmental changes during a press-forming process, for example, a temperature change of a mold in a continuous press-forming process, an abrasion of the mold, changes of temperature and humidity of an atmosphere, etc., even if the characteristic mechanical properties of the material itself remain uniform.
For example, a technique for performing a forming process by controlling forming conditions in accordance with conditions of a material and a mold is described in Japanese Patent Application No. Hei 7-266100. A relationship can be determined in advance between a shape of a press material, mechanical and chemical properties of the press material, lamination characteristics such as a plating, and physical characteristics of the material surface, such as oil quantity present, and/or a blank-holder load capable of obtaining a predetermined press quality. An adequate blank-holder load can be determined based on a relationship between a predetermined physical quantity of the press material and the press-forming conditions capable of obtaining the predetermined press quality. Air pressure of an air cylinder can thus be controlled so that a press-forming process can be performed with an adequate blank-holder load.
For example, techniques in which press conditions are adjusted based on machine information and mold information unique to a press-forming device are described, e.g., in Japanese Patent Application Nos. Hei 5-285700 and Hei 6-246499.
Further, techniques in which a material to be processed can be adjusted to a predetermined bending angle in a bending press-forming process using a press brake are described, e.g., in Japanese Patent Application Nos. Hei 7-265957, Hei 10-128451, and Hei 8-300048.
Material characteristics and environments can vary temporarily or momentarily when a material is press-formed. However, it can be extremely difficult to predict the above-described variation of material characteristics and environmental changes when the material to be processed is press-formed beforehand, even if the blank-holder load is controlled based on the material characteristics, information unique to the press-process device, and/or the mold information, as described in Japanese Patent Application Nos. Hei 7-266100, Hei 5-285700, and Hei 6-246499 described above. Further, it can be difficult to measure and characterize a complicated three-dimensional shape such as a drawing press-process and a cutting press-process on the moment. Additionally, the material to be press-processed during the press-forming process can be engaged by the mold, and therefore it may be very difficult to measure an accurate shape, even if the forming conditions are adjusted in accordance with a deformed state of the material during press-forming as described, e.g., in the above-cited Japanese Patent Application No. Hei 7-265957, Japanese Patent Application No. Hei 10-128451, and Japanese Patent Application No. Hei 8-300048.
Thus, there may be a need for improved systems, methods, software arrangements and computer-accessible media for press-forming of materials which overcome the above-mentioned deficiencies.
USPTO Backgrounds
USPTO Backgrounds