This application is a national stage application of PCT Application No. PCT/JP2005/016527 which was filed on Sep. 8, 2005 and published on Mar. 16, 2006 as International Publication No. WO 2006/028175, the entire disclosure of which is incorporated herein by reference. This application claims priority from the International Application pursuant to 35 U.S.C. §365, and from Japanese Patent Application No. 2004-264434, filed Sep. 10, 2004, under 35 U.S.C. §119, the entire disclosures of which are incorporated herein by reference.
The present invention relates to a system, method, computer software arrangement and computer-accessible medium for press-forming of a material.
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.
One object of the present invention is to provide an improved press-forming process for materials.
In a press-forming system according to exemplary embodiments of the present invention, a processing device such as, e.g., a computer, can be configured to control a press machine and can be connected to a network. The computer can receive detailed material characteristics of metallic materials on demand from a server-side computer via the network, where such characteristics may be difficult to obtain using conventional techniques. The computer can also receive information relating to environmental changes and process shapes associated with the press machine from various measuring devices (e.g., sensors) provided at the press machine. Such information may also be difficult to obtain in a timely manner using conventional techniques. In this manner, a system can be provided in which press-forming conditions can be calculated based on variations of the material characteristics and changes in the environment of the press machine, the press machine can be controlled based on the calculated press forming conditions, and improved press-formed products can be obtained.
A press forming system in accordance with exemplary embodiments of the present invention can be provided which has a press-forming apparatus configured to press-form a material, a user-side computer configured to accept user input and to control the press-forming apparatus, a material property database which may store material identification numbers for identifying the material being press-formed by the press-forming apparatus, where certain material property data in the database can be associated with the material identified by the material identification number, and a computer server device connected to the user-side computer via a network. The user-side computer can include a data input arrangement for providing a material identification number, and a material identification number transmission arrangement configured to transmit the material identification number. The server side computer can include a receiving arrangement configured to receive the material identification number transmitted by the material identification number transmission arrangement, and a material property data transmission arrangement configured to transmit the material property data stored in the material property database which corresponds to the received material identification number. The user-side computer can further include a material property data receiving arrangement configured to receive the material property data. The press-forming apparatus can include a punch, a die and a blank-holder, and can further include a process condition control arrangement configured to press-form a material using one or more process conditions based at least in part on the material property data received by the material property data receiving arrangement.
A press-forming method can be provided in accordance with exemplary embodiments of the present invention which can include: inputting a material identification number, which can identify a material to be press-formed, using a user-side computer; transmitting the material identification number to a server-side computer; receiving the material identification number using the server-side computer via a network; transmitting material property data stored in a material property database which corresponds to the received material identification number; receiving the material property data using the user-side computer; and press-forming the material using at least one process condition based on the received material property data.
A software arrangement and a computer-accessible medium in accordance with exemplary embodiments of the present invention can be provided which includes, e.g.: instructions which, when executed, can configure a processing arrangement associated with a user-side computer to receive a material identification number identifying a material to be press-formed; instructions which, when executed, can configure a processing arrangement to transmit the material identification number from the user-side computer to a server-side computer; instructions which, when executed, can configure a processing arrangement associated with a server-side computer to receive the material identification number; instructions which, when executed, can configure a processing arrangement associated with a server-side computer to transmit material property data via a network, where the material property data may be stored in a material property database and can correspond to the material identification number received via a network; instructions which, when executed, can configure a processing arrangement associated with a server-side computer to transmit the material property data to the user-side computer; and instructions which, when executed, can configure a processing arrangement to control a press-forming apparatus by varying at least one process condition based on the received material property data.
These and other objects, features and advantages of the present invention will become apparent upon reading the following detailed description of embodiments of the invention, when taken in conjunction with the appended claims.
Further objects, features and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying figures showing illustrative embodiments, results and/or features of the exemplary embodiments of the present invention, in which:
Throughout the figures, the same reference numerals and characters, unless otherwise stated, are used to denote like features, elements, components or portions of the illustrated embodiments. Moreover, while the present invention will now be described in detail with reference to the figures, it is done so in connection with the illustrative embodiments.
The material property data providing device 101 can be configured to provide material property data, representing characteristics of a material to be press-formed by the press-forming device 102, to the condition-setting calculation device 104 based on a request from the condition-setting calculation device 104. The material property data providing device 101 can be associated with, e.g., a personal computer.
For example, a cold-rolled high tensile strength steel sheet with a tensile strength of 590 [MPa], a sheet thickness of 1.4 [mm], and a sheet surface size of 1000 [mm]×500 [mm] can be provided as an exemplary material to be processed. Such cold-rolled high tensile strength steel sheets can be provided in 100-sheet packages to the press-forming system. Production lot numbers can be associated with such packages. Material property data can be provided for the cold rolled high tensile strength steel sheet which can include, for example, one or more of sheet thickness, a yield stress, a tensile strength, 0.2% proof stress, an elongation, an n-value, an r-value, a relational expression between a stress and a strain, a hardness, a temperature, a surface roughness, a friction coefficient, a lubricant film thickness, and so on.
The material identification number receiving portion 101a can be configured to receive a material identification number transmitted from the condition-setting calculation device 104, as described herein below. In certain exemplary embodiments of the present invention, the material identification number can correspond to a production lot number supplied with the package of sheets.
The material property search portion 101b can search the material property data contained in the material property database 106 which corresponds to the material identification number received by the material identification number receiving portion 101a. As stated above, the material property data can be identified in the material property database 106 by a material identification number.
The material property data encryption portion 101c can encrypt the material property data searched by the material property search portion 101b. The material property data transmission portion 101d can transmit the encrypted material property data to the condition-setting calculation device 104.
The billing portion 101e can update, for example, a transmission history file (which can include, e.g., a client name, connection date and time, transmission data amount, and so on) when the material property data is transmitted to the user-side condition-setting calculation device 104. It can also be configured to aggregate the transmission history file periodically, and may generate bills based on a total communication quantity.
In
The control device 103 can be configured to control operations of the press-forming device 102 and/or to monitor operations of the press-forming device 102 in accordance with the forming conditions provided by the condition-setting calculation device 104. The press-forming device 102 can press-form the material based on control provided by the control device 103. As described above, a press-forming apparatus can include both a press-forming device 102 and a control device 103 in accordance with certain exemplary embodiments of the present invention.
The press-forming device 102 shown in
Additional components of the press-forming device 102 can be provided such as, e.g., an air cylinder, a hydraulic cylinder, a heater, and/or a hydraulic controller, even though such additional components are not shown in
The control device 103 can include a speed control device 103a, a blank-holder force control device 103b, a temperature control device 103c, a mold distortion measuring unit 103d, a punch reaction force measuring unit 103e, a mold temperature measuring unit 103f, a material deformation measuring unit 103g, a state quantity storage unit 103h, a control calculation unit 103i, and/or a state measuring unit 103j.
The speed control device 103a can be provided to control a forming speed defined by, e.g., a drive speed of the die 102a. The blank-holder force control device 103b can be provided to control a blank-holder pressure (e.g., a blank-holder force) provided by the blank holder 102e to the material to be processed 300. The temperature control device 103c can be provided to control the temperature of the mold.
The mold distortion measuring unit 103d can be provided to measure a distortion of the mold by reading a detected value of the strain sensor 102b. The punch reaction force measuring unit 103e can be provided to measure the punch reaction force by reading a detected value of the load cell 102c. The mold temperature measuring unit 103f can be provided to measure the temperature of the mold and the material to be processed 300 by reading a detected value of a temperature sensor (e.g., a thermocouple) attached to the die 102a, the punch 102d, and so on.
The material deformation measuring unit 103g can be provided to measure a degree of deformation of the material to be processed 300. The state measuring unit 103j can be provided to measure the material to be processed 300 before a press-forming process to obtain material property measurement data. Examples of material property measurement data which may be measured can include, e.g., data based on a hardness, a surface roughness, a friction coefficient, and so on.
The state quantity storage unit 103h can be provided to store a history of state quantity of the press-forming device 102 which may be measured by the mold distortion measuring unit 103d, the punch reaction force measuring unit 103e, the mold temperature measuring unit 103f, the material to be processed deformation measuring unit 103g, and/or the state measuring unit 103j as described above. The control device 103 can thus be used to provide control over certain process conditions, as described above.
The condition-setting calculation device 104 may have a forming condition input portion 104a, a material identification number input portion 104b, a material identification number transmission portion 104c, a material property data receiving portion 104d, a material property data decryption portion 104e, and a forming condition calculation portion 104f.
The forming condition input portion 104a can be provided to receive and store basic forming conditions based on an operation of an operation portion provided by a user. In certain exemplary embodiments of the present invention, the forming condition input portion 104a can receive information such as a blank-holder force, a forming speed, a mold temperature, and so on, as the basic forming conditions.
The material identification number input portion 104b can be provided to receive the input of a material identification number based on a user's operation for a material characteristic inquiry screen 401 as shown in
The material identification number transmission portion 104c can be provided to transmit the material identification number (production lot number) to the material property data providing device 101 when, e.g., a transmission button is pressed by the user after the material identification number (e.g., a production lot number) is provided to the material characteristic inquiry screen 401 shown in
The material property data receiving portion 104d can be provided to receive encrypted material property data transmitted from the material property data providing device 101 in response to the material identification number transmitted by the material identification number transmission portion 104c.
The material property data decryption portion 104e can be used to decrypt the encrypted material property data for calculating the forming conditions.
The condition-setting calculation device 104 can include a material property receive screen 402, as shown in
The forming condition calculation portion 104f can be provided to calculate or determine forming conditions in the press-forming device 102 by using the material property data received by the material property data receiving portion 104d, the state quantity of the press-forming device 102 stored in the state quantity storage unit 103h, and so on.
Operation of an exemplary press-forming system in accordance with exemplary embodiments of the present invention may be described with reference to the flow charts shown in
The press-forming system can wait until the material to be processed 300 is provided to the press-forming device 102 (step S1). When the material to be processed 300 is provided to the press-forming device 102, the material identification number input portion 104b of the condition-setting calculation device 104 can determine whether or not the material identification number has been provided and the transmission button has been pressed, based on the user's operation of the material property inquiry screen 401 shown in
When the material identification number is provided and the transmission button is pressed as a result of the above determination, the material identification number transmission portion 104c of the condition-setting calculation device 104 transmits the material identification number to the material property data providing device 101 (step S3).
Next, the material identification number receiving portion 101a of the material property data providing device 101 determines whether the material identification number transmitted at the step S3 is received or not (step S4).
When the material identification number is received, the material property search portion 101b of the material property data providing device 101 obtains the material property data corresponding to the material identification number from the material property database 106 (step S5).
Next, the material property data encryption portion 101c of the material property data providing device 101 encrypts the material property data (step S6).
The material property data transmission portion 101d of the material property data providing device 101 then transmits the encrypted material property data to the condition setting calculation device 104 (step S7).
Next, the material property data receiving portion 104d of the condition-setting calculation device 104 can determine whether or not the transmitted encrypted material property data is received (step S8).
When the material property data is received, the material property data decryption portion 104e of the condition setting calculation device 104 may decrypt the material property data (step S9). The material property data receiving portion 104d can then record the decrypted material property data (step S10).
Next, the forming condition input portion 104a of the condition-setting calculation device 104 may determine whether or not the basic forming conditions have been provided based on the user's operation (step S11). When the basic forming conditions are provided, the forming condition input portion 104a can store the basic forming conditions (step S12).
The state measuring unit 103j of the control device 103 may then measure the hardness, the surface roughness, the friction coefficient, and so on of the material to be processed 300, and can store the material property measurement data based on the measured hardness, surface roughness, and friction coefficient (step S13).
Next, the forming condition calculation portion 104f of the condition-setting calculation device 104 can read the history of the state quantity of the press-forming device 102 stored in the state quantity storage unit 103h of the control device 103 (step S14). At this time, the forming condition calculation portion 104f can also read the material property measurement data stored in step S13.
Next, the forming condition calculation portion 104f corrects the forming conditions of the press-forming device 102 based on the material property data stored in step S10, the basic forming conditions stored in step S12, and the history of the state quantity of the press-forming device 102 and the material characteristic measurement data read at step S14 (step S13).
For example, an initial value “C0(i)” of a forming condition can be corrected by using the following relationship:
C0′(i)=C0(i)×(1+Σ(T1(i, j)×P(j)/P0(j)−1))); i=1 to L, j=1 to M. (EXPRESSION 1)
In this Equation, “C0′(i)” can be a Forming Condition Determined Based on the correction. “T1(i, j)” can be an influence function matrix representing a relationship between a deviation of a material property of the material to be processed 300 relative to a standard value, and a correction amount of the forming condition. “P(j)” can be an actual performance value associated with each material property. “P0(j)” can be a standard or reference value of each material property. “M” can represent the number of material properties considered. “L” can refer to the number of setting values of the forming condition.
Here, the initial value “C0(i)” of the forming conditions may be constant or it may change during the forming process. When it is changed during the forming process, for example, a setting value for a stroke amount of the punch 102d may be provided.
Components of the influence function matrix “T1(i, j)” can be obtained from a change of an optimal forming condition (e.g., a sensitivity analysis) relative to changes of various material properties, by using a forming simulation based on, e.g., a finite element method. Such components may also be determined statistically based on, e.g., a relationship between a variation of the material properties and the forming conditions and certain measurements of product quality (e.g., cracks, wrinkles, springback, surface distortion, and so on) obtained from an actual mass production press. Alternatively, an actual measured value of the product quality can be provided to the press-forming device 102 as instruction data and, for example, it may be created and updated by using a learning function such as one provided by a neural network. Techniques for relating material properties and forming conditions are not limited to those described above, and arbitrary settings may also be used.
Referring to
Next, the mold distortion measuring unit 103d, the punch reaction force measuring unit 103e, the mold temperature measuring unit 103f, and/or the material to be processed deformation measuring unit 103g may measure the state quantity of the press-forming device 102 during the press-forming process (step S17).
The forming condition calculation portion 104e can then determine whether a difference of the state quantity measured in step S17 and a target state quantity defined in advance is within a tolerance range or not (step S18). When the difference is within the tolerance range as a result of this determination, the control calculation unit 103i then determines whether the press-forming process is completed or not, for example, based on the measured result of the material to be processed deformation measuring unit 103g (step S19).
When the press-forming of the material can be completed as a result of this determination, the state quantity measured in step S17 may be stored or recorded in the state quantity storage unit 103h (step S20). The process then goes back to step S1, and can wait for an acceptance of the next material to be processed 300. If the press-forming process is not completed, the process goes back to step S17, and the state quantity is measured again.
When it is determined that the difference between the state quantity measured in step S17 and the pre-defined target state quantity is not within the tolerance range in step S18, the forming condition calculation portion 104f can correct the forming condition (step S21). The process then goes back to step S17, and the state quantity is measured again.
The forming condition “C0′(i)” provided in Expression (1) above can be corrected by using the following relationship:
C(i)=C0′(i)×(1+Σ(T2(i, k)×S(k)/S0(k)−1))); i=1 to L, k=1 to N. (EXPRESSION 2)
In this expression, “C(i)” can represent a correction value for the forming condition. “T2(i, k)” can be an influence function matrix representing a relationship between a deviation of the measured various state quantities relative to a standard value and a correction amount of a forming condition. “S(k)” can represent the state quantity measured in step S17. “S0(k)” can be a standard or reference value of the state quantity. “N” can represent the number of the state quantities considered.
Components of the influence function matrix “T2(i, k)” can be obtained from the change of the optimal forming condition (e.g., a sensitivity analysis) relative to the changes of various material characteristics by using a forming simulation employing, e.g., a finite element method, similar to the manner in which components of the influence function matrix “T1(i, j)” can be determined. The components can also be determined statistically based on a relationship between a variation of the material properties and the forming condition and a measure of product quality (e.g., cracks, wrinkles, springback, surface distortion, and so on) produced in the actual mass production press. Alternatively, an actual measured value of the product quality can be provided to the press-forming device 102 as instruction data and, for example, it can be created and updated by using a learning function such as that provided by a neural network. Determination and formulation of a state quantity are not limited to the techniques described above, and arbitrary settings may also be used.
As described above, the actual performance value and the standard value of a material property may be compared, forming conditions such as the forming speed and the blank-holder pressure can be corrected based on this comparison, and the press-forming process may then be started using the corrected forming conditions. Therefore, it may be possible to reduce the occurrences of cracks and wrinkles, and to suppress influences of variable factors difficult to predict such as the variation of the material properties and/or environmental changes that may occur when the material is press-formed. Accordingly, it may be possible to determine improved forming conditions, and to obtain desirable formed products.
The flow charts shown in
Further, the material identification number (e.g., production lot number) can be provided using a keyboard or a mouse provided in connection with the condition setting calculation device 104, but the material identification number may not necessarily be provided as described above. For example, a barcode storing information relating to the production lot number can be attached to the material to be processed 300. The barcode can be read by a barcode reader, the production lot number of the material to be processed 300 can be determined based on the barcode information, and the determined production lot number can be transmitted to the material property data providing device 101.
The production lot number may also be stored, e.g., in an IC tag, a disk recording medium such as, e.g., a flexible disk, a magnetic disk or an optical disk, etc., and the number may be transmitted from such media to the material property data providing device 101.
In one exemplary embodiment of the present invention, a cold-rolled high tensile strength steel sheet with a tensile strength of 590 [MPa], a sheet thickness of 1.4 [mm], a size of a sheet surface of 1000 [mm]×500 [mm] can be provided as a material to be processed.
The condition setting calculation device 104 may receive material property data such as actual performance values of the tensile strength, 0.2% proof stress, a total elongation, and the sheet thickness from the material property data providing device 101.
Next, initial values of the forming speed and the blank-holder pressure can be corrected for each production lot by using Expression (1) above using the actual performance values of the material properties before the press-forming process is performed. For example, the standard value “P0(j)” of the material properties can be provided by Expression (3) below, the actual performance value “P(j)” of the material properties can be provided by Expression (4) below, the standard value “C0(i)” of the forming conditions can be provided by Expression (5) below, and the influence function matrix “T1(i, j)” can be obtained from Expression (6) below. These values can each substituted into Expression (1), and a correction value “C0′(i)” of the forming conditions can be obtained as shown in Expression 7 below.
Next, a test press can be performed, where the punch reaction force measuring unit 103e and the mold distortion measuring unit 103d can measure the punch reaction force and the mold distortion during the forming, respectively. After it has been confirmed that the press-formed product obtained by performing the test press is not defective and has no cracks, wrinkles, or the like, the forming condition calculation portion 104f of the condition-setting calculation device 104 can provide a forming speed and a blank-holder pressure based on Expression 7 above. A measured maximum value of the punch reaction force and a maximum value of the mold distortion can be used as standard values of the state quantity. In the example shown above in Expression 3-Expression 7, the forming condition calculation portion 104f can sets a standard value “S0(k)” of the state quantity shown below:
The forming condition calculation portion 104f may calculate the forming condition “C(i)” using Expression 2 above, and outputs the calculated forming condition “C(i)” to the control calculation unit 103i of the control device 103. The control calculation unit 103i can start the press-forming process based on this forming condition “C(i)”.
The maximum value of the punch reaction force and the maximum value of the mold distortion during the forming can then be measured each time the press-forming process is performed, and the forming speed and the blank-holder pressure can be corrected in accordance with the difference between the measured maximum value of the punch reaction force and maximum value of the mold distortion, and the set standard values.
For example, when the measured value “S(k)” of the state quantity defined based on the maximum value of the punch reaction force and the maximum value of the mold distortion during the forming reaches the values shown in Expression 9 below, the forming condition calculation portion 104f can substitute the setting value “C0′(i)” of the forming condition shown in Expression 7, the standard value “S0(k)” of the state quantity shown in Expression 8, and the influence function matrix “T2(i, k)” shown in Expression 10 below into Expression 2. A correction value “C(i)” of the forming condition can then be obtained as shown in Expression 11 below. Incidentally, in the above description, the influence function matrix “T2(i, k)” can be set in advance.
As described above, the punch reaction force and the mold distortion during the press-process can be measured in addition to the material property data received from the material property data providing device 101, and the forming speed and the blank-holder pressure can be corrected in accordance with the measured results. Therefore, it becomes possible to determine improved forming conditions of the material to be processed 300, and to obtain a better-formed product.
As described above, the forming speed and the blank-holder pressure are corrected each time the press-forming process is performed. However, these values may be corrected after a number of press-forming processes have been performed. Further, the maximum value of the punch reaction force and the maximum value of the mold distortion during the press-forming process can be set equal to the standard value “S0(k)” of the state quantity, but the standard value “S0(k)” of the state quantity can be determined from a time-series of data of the punch reaction force and a time-series of data of the mold distortion during the press-forming process. For example, values of these parameters obtained at several points within the time-series of data may be used to evaluate the standard value “S0(k)” of the state quantity.
Additionally, the press-forming process can be performed without changing the forming speed and the blank-holder pressure as shown in Expression 11, but these values may be changed during the press-forming process in accordance, e.g., with a punch stroke.
In a further exemplary embodiment of the present invention, the condition setting calculation device 104 can receive actual performance values of the tensile strength, the 0.2% proof stress, the total elongation, and the sheet thickness from the material property data providing device 101. Additionally, the condition-setting calculation device 104 can provide material property data which may not be provided by the material property data providing device 101, e.g., material property data which may not be known by an operator of the material property data providing device 101, based on an operation by a user of the operation portion provided at the condition setting calculation device 104. For example, a procedure can be provided in which an actual performance value of a lubricant film thickness is provided as an example of such material property data.
The forming condition calculation portion 104f can correct forming conditions such as, e.g., the forming speed and the blank-holder pressure by using Expression 1 based on the received material property data and the inputted material property data.
The forming conditions can be corrected, for example, by substituting the standard value “P0(j)” of the material properties shown in Expression 12 below, the influence function matrix “T1(i, j)” shown in Expression 13 below, and the actual performance value “P(j)” of the material properties defined from the above-stated material property data into Expression 1.
As described above, the forming conditions can be corrected by considering the material property data which may be known only at the user side using the condition setting calculation device 104, in addition to the material property data received from the material property data providing device 101. Therefore, it may be possible to suppress an influence of variable factors such as a lubricity between the mold and the material to be processed 300 and a surface property, in addition to the variation of the material properties and the environmental changes which may be present. Accordingly, a more desirable forming condition can be obtained in such circumstances.
In a further exemplary embodiment of the present invention, the condition setting calculation device 104 can again receive material property data in the form of actual performance values of the tensile strength, the 0.2% proof stress, the total elongation, and the sheet thickness from the material property data providing device 101. However, a representative value of a particular production lot (for example, the representative value of 100 sheets of materials to be processed 300) can also be received as material property data.
The condition setting calculation device 104 can provide material property data which may exhibit a large variation depending on the particular material to be processed 300, via the operation of the operation portion by the user provided at the condition setting calculation device 104. For example, an actual performance value of Vickers hardness of a particular material to be processed 300 can be provided as an example of such material property data.
The forming condition calculation portion 104f can correct the forming conditions such as, e.g., the forming speed and the blank-holder pressure by applying Expression 1 based on the received material property data and the provided material property data.
For example, the standard value “P0(j)” of the material characteristics shown in Expression 14 below, the influence function matrix “T1(i, j)” shown in Expression 15 below, and the actual performance value “P(j)” of the material characteristics defined based on the above-cited material property data can be substituted into Expression 1 to set the forming conditions.
As described above, the material property data, which can have a large effect on the press-forming process unless it is considered for each material to be processed 300, can be measured at the user side separately, and the forming conditions may be corrected using this the measured material property data. Therefore, it is possible to press-form the material adequately even if the material property data received from the material property data providing device 101 corresponds to a representative value of the particular production lot.
In a still further exemplary embodiment of the present invention, the condition setting calculation device 104 can receive actual performance values of the tensile strength, the 0.2% proof stress, the total elongation, and the sheet thickness from the material property data providing device 101 to use as the material property data. In addition, when the punch reaction force during the press-process exceeds a certain tolerance range, the blank-holder pressure can be adjusted so that the punch reaction force is within the tolerance range, and the press-process is continued with the adjusted bank-holder pressure.
For example, the standard value “P0(j)” of the material properties can be provided by Expression 16 below, the actual performance value “P(j)” of the material characteristics can be that shown in Expression 17, the standard value “C0(i)” of the forming conditions can be that shown in Expression 18, and the influence function matrix “T1(i, j)” can be that shown in Expression 19. These values can be substituted into Expression 1, and the correction value “C0′(i)” of the forming conditions in Expression 20 below can be obtained.
The press-forming process can be started in accordance with the correction value “C0′(i)” of the forming conditions. After the press-forming process is started, the punch reaction force during the press-process can be measured by using the punch reaction force measuring unit 103e as described above, and the maximum value of the measured punch reaction force can be stored in a recording medium provided at the condition setting calculation device 104 each time the press-forming process is performed.
The forming condition calculation portion 104f of the condition setting calculation device 104 can determine whether a moving average value, e.g., of 10 points of the punch reaction forces stored in the recording medium is within a pre-set tolerance range. When it is not within the tolerance range, the blank-holder pressure can be adjusted as described above, and the press-process is continued.
In the exemplary data shown in
For example, when the measured value “S(k)” of the state quantity defined from the maximum value of the punch reaction force reaches a value shown in Expression 21 below, the correction value “C0′(i)” of the forming conditions shown in Expression 20, the influence function matrix “T2(i, k)” shown in Expression 22 below, and the standard value “S0(k)” of the state quantity in Expression 23, may each be substituted into Expression 2, and the correction value “C(i)” of the forming conditions shown in Expression 24 can be obtained. In this exemplary procedure, the influence function matrix “T2(i, k)” can be set in advance.
As described above, the blank-holder pressure can be adjusted so that the punch reaction force returns to a value within the tolerance range when the punch reaction force during the press-forming process exceeds the tolerance range. Therefore, it may be possible to further reduce the occurrence of defective products, and to press-form a predetermined number of materials to be processed 300 in an improved manner.
The present example describes an exemplary process in which the blank-holder pressure is adjusted so that the punch reaction force remains within the tolerance range, and the press-forming process is continued using the adjusted blank-holder pressure. However, any one or more of the blank-holder pressure, the forming speed, or the mold temperature may be adjusted in this manner such that the state quantity exceeding the tolerance range returns to a value within the tolerance range, when the state quantity of, e.g., the punch reaction force, the mold temperature, the mold distortion amount, the deformation amount of the material to be processed 300, and/or the temperature of the material to be processed 300 exceeds a tolerance range during the press-forming process.
Additionally, a current value and an actual previous performance value of the state quantity such as the punch reaction force can be compared, and process conditions such as the blank-holder pressure may be adjusted in accordance with the compared result. For example, when a difference between the current value and the actual previous performance value of the state quantity such as, e.g., the punch reaction force exceeds a predetermined value, the blank-holder pressure can be adjusted so that the resulting difference does not exceed the predetermined value.
Further, the moving average value of, e.g., 10 points of the state quantity of the punch reaction force can be evaluated as being within the pre-set tolerance range or not, but the moving average value of the state quantity within a predetermined time may be evaluated as being within the pre-set tolerance range or not.
In a yet further exemplary embodiment of the present invention, the condition setting calculation device 104 can receive actual performance values of the tensile strength, the 0.2% proof stress, the total elongation, and the sheet thickness from the material property data providing device 101 as the material property data. However, the received material property data can be encrypted by the material property data providing device 101, and the press-forming can be performed using a procedure such as that described in Example 1 above after the material property data is decrypted by the condition setting calculation device 104. At this time, the material property data providing device 101 can be managed by a material manufacturer, and a transmission history file (containing, e.g., client name, connection date and time, amount of transmission data, and so on) may be updated each time the material property data is transmitted to a customer using the condition setting calculation device 104. The transmission history file can be periodically aggregated to generate a bill in accordance with a total communication amount. Accordingly, it is possible for the customer to obtain accurate material property data for each material processed while maintaining confidentiality of the data. Therefore, it is not necessary for the operator to experientially correct the forming conditions each time, and quality variation of the formed products may be reduced. Additionally, efforts needed to prepare a conventional paper-based mil sheet may be drastically reduced for the material manufacturer by the encryption and billing techniques described herein. Further, prevention of unauthorized copying and/or re-use of the material property data can be achieved, which can assist in covering administrative and/or maintenance expenses for this system while securing the confidentiality of the material property data.
Exemplary embodiments of the present invention also include, for example, computer program codes (e.g., in the form of software arrangements), where such program codes may be provided to configure, e.g., a computer or other processing arrangement associated with a piece of equipment or a system connected to various devices so as to at least in part control or operate the various devices in accordance with the various exemplary embodiments described herein. Such program codes may be provided in a form of any computer-accessible medium, e.g., a flexible disk, a hard disk, an optical disk, a magnetic optical disk, a CD-ROM, a magnetic tape, a non-volatile memory card, a ROM, and so on.
Such program codes, which may be operable in conjunction with an operating system, other application software, or the like through a computer or other processing arrangement to thereby realize the functions of the exemplary embodiments described herein, are also considered to be within the scope of the present invention. These program codes and/or software arrangements may also be stored, e.g., in a memory included in a function expansion board of a computer or a function expansion unit connected to the computer, and a CPU or other processing arrangement may be further included in the function expansion board or the function expansion unit to perform a part or all of the actual processes based on instructions provided by the program codes, such that the functions of the exemplary embodiments can be realized by the processes.
According to exemplary embodiments of the present invention, a material may be press-formed using process conditions based on material property data transmitted from a server-side computer to a user-side computer via a network. In this manner, it may be possible to define forming conditions which can account for variations of the material properties. Accordingly, improved forming conditions may be determined, and more reliable and higher-quality formed products can be obtained.
The foregoing merely illustrates the principles of the invention. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements, media and methods which, although not explicitly shown or described herein, embody the principles of the invention and are thus within the spirit and scope of the present invention. In addition, all publications referenced herein above are incorporated herein by reference in their entireties.
Number | Date | Country | Kind |
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2004-264434 | Sep 2004 | JP | national |
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PCT/JP2005/016527 | 9/8/2005 | WO | 00 | 3/9/2007 |
Publishing Document | Publishing Date | Country | Kind |
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WO2006/028175 | 3/16/2006 | WO | A |
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