Method and system for electrostatically charging stamping lubricant to control deposition

Abstract

The present disclosure provides methods and systems for electrostatically charging stamping lubricants to control deposition. A method of lubricating a sheet of material includes moving the sheet in a first direction and operating a printing nozzle to deposit a lubricant on the sheet as the sheet moves in the first direction. The printing nozzle sprays a lubricant in a second direction transverse to the first direction and toward the first side of the sheet. The method includes charging the lubricant such that the lubricant ejected from the printing nozzle is in the form of charged droplets, and applying an external electric field between the printing nozzle and the sheet to attract the charged droplets to the sheet.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Application No. 18 / 360,255, filed on July 27, 2023, and entitled “METHOD AND SYSTEM FORELECTROSTATICALLY CHARGING STAMPING LUBRICANT TO CONTROL DEPOSITION,” the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present disclosure relates to methods and systems for lubricating sheet metal and forming metal parts therefrom. Background Art

[0004] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0005] Some mass-produced metal parts, such as, for example, body panels for vehicles, may start out as sheet metal coils. The coils are typically unwound in a continuous manner while being cut into discrete flat sheet metal blanks. Sheet metal blanks are typically discrete flat sheets of material having a predetermined length and shape. Each sheet metal blank is then coated with a uniform thickness of lubricant before being moved to a press line or being stacked for storage until ready to be moved to a press line. A press line typically includes one or more stamping presses configured to form the flat sheet metal blanks into three-dimensional metal parts. Some stamping presses also remove small amounts of sheet metal during the stamping process.

[0006] Lubricants are usually applied to the sheet metal blanks with uniform thickness across the entire length and width of the sheet metal blanks, regardless of the stamping process. In addition, the lubricant application systems currently used usually result in excessive lubricant consumption and overspray, which require complex and expensive capture and recovery technologies. In addition, stacking completely and evenly lubricated sheet metal blanks may cause lubricants to squeeze out from the edges. This extruded lubricant may cause the stacked sheet metal blanks to stick together, which may make it difficult to remove a single sheet metal blank from the stack, such as with a robotic arm. Inadvertently loading two sheet metal blanks that stick together into a stamping press may damage the stamping press and stop production. In addition, excessive lubrication may make it more difficult to clean, pre-treat and paint metal parts after stamping.

[0007] The present disclosure addresses these and other problems associated with conventional sheet metal lubrication and stamping operations and apparatus. Summary of the invention

[0008] This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.

[0009] According to one form of the teachings of the present disclosure, a method of lubricating a sheet of material includes moving the sheet in a first direction, and operating a print nozzle to deposit a lubricant on the sheet while the sheet moves in the first direction. The print nozzle ejects the lubricant in a second direction transverse to the first direction and toward a first side of the sheet. The method includes charging the lubricant so that the lubricant ejected from the print nozzle is in the form of charged droplets, and applying an external electric field between the print nozzle and the sheet to attract the charged droplets to the sheet.

[0010] According to a variation of the method that can be used alone or in any combination, the method also includes adjusting the speed of the charged droplets by adjusting the external electric field; controlling the strength of the external electric field based on the speed at which the plate moves along the first direction; the plate is a metallic material; charging the lubricant before it is ejected from the print nozzle; charging the lubricant as it is ejected from the print nozzle or immediately after it is ejected from the print nozzle; the print nozzle is located below the plate; the external electric field is in the range of 30 to 120 kV / m; the charged droplets are positively charged; the positive charge is in the range of 10 to 200 kV; the charge carried by the charged droplets reaches a range of 10 to 200 kV; the lubricant is charged by a first charging device, and the external electric field is provided by a second charging device separate from the first charging device.

[0011] According to another form of the teachings of the present disclosure, a method for lubricating a sheet of material includes moving the sheet along a first direction, and operating a print nozzle to deposit lubricant on the sheet while the sheet moves along the first direction. The print nozzle ejects the lubricant in a second direction transverse to the first direction and toward a first side of the sheet. The method includes: charging the lubricant with a first charging device so that the lubricant ejected from the print nozzle is in the form of charged droplets; operating a second charging device to apply an external electric field between the print nozzle and the sheet to attract the charged droplets to the sheet; and adjusting the velocity of the charged droplets by adjusting the strength of the external electric field.

[0012] According to a variant of the method, which may be employed alone or in any combination, the strength of the external electric field is controlled based on the speed at which the sheet moves along the first direction; the printing nozzle is located below the sheet.

[0013] According to another form of the teachings of the present disclosure, a system for lubricating a metal plate to be formed into a metal part includes a print head, a first charging device, a second charging device, and a control module. The print head includes a plurality of nozzles. Each of the plurality of nozzles includes an orifice plate, an actuator, and a body. The orifice plate and the body cooperate to define a reservoir, which is configured to hold a lubricant. The actuator is configured to vibrate the lubricant in the reservoir so that the lubricant is ejected as droplets through the holes of the orifice plate. The first charging device is configured to charge the lubricant. The second charging device is configured to generate an external electric field between the print head and the metal plate. The control module is configured to control the operation of the second charging device to selectively adjust the strength of the external electric field.

[0014] According to variations of the system that may be employed individually or in any combination, the control module is configured to selectively adjust the strength of the external electric field based on the speed at which the plate moves along the first direction; the first charging device is configured to charge the lubricant before the lubricant is ejected from the print nozzle; the first charging device is configured to charge the lubricant as the lubricant is ejected from the print nozzle or immediately after the lubricant is ejected from the print nozzle; the first charging device is configured to charge the lubricant in the range of 10 to 200 kV and the external electric field in the range of 30 to 120 kV / m.

[0015] According to one form of the teachings of the present disclosure, a method of manufacturing a metal part is provided. The method includes: performing a test stamping process on a test sheet metal blank; generating a strain map of the test sheet metal blank for the test stamping process; generating a lubrication program based on the strain map; applying lubrication to the sheet metal according to the lubrication program; and stamping the sheet metal to form the metal part. The lubrication program is configured to control a lubrication system to apply lubrication to the sheet metal in a non-uniform distribution across the sheet metal. The non-uniform distribution is related to the strain map.

[0016] According to a variation of the method that may be employed alone or in any combination: lubrication is applied by a print head comprising a plurality of print nozzles, each print nozzle being individually controlled by a lubrication program; the method further comprising linearly moving the metal sheet while the print head applies lubrication to the metal sheet; the lubrication program being configured to apply lubrication to a first region of the metal sheet according to a first thickness and to apply lubrication to a second region of the metal sheet according to a second thickness, the first thickness being thicker than the second thickness; the first region of the metal sheet is associated with a strain map region having a higher strain than a strain map region associated with the second region of the metal sheet; the print head being configured to apply lubrication pixels to the metal sheet such that the size of each lubrication pixel is between 20 microns and 3,000 microns; the lubrication program being configured to: vary the spacing between pixels, or vary the size of pixels, or vary both the spacing between pixels and the size of pixels; the plurality of print nozzles comprising a first subset of print nozzles and a second subset of print nozzles, wherein applying lubrication to the metal sheet comprises applying a liquid lubricant to the metal sheet from the first subset of print nozzles and applying a dry film lubricant to the metal sheet from the second subset of print nozzles; the lubrication program being configured to apply lubrication pixels to the metal sheet during the application of lubrication to the metal sheet blank less lubrication is applied near the edge of the sheet metal; applying lubrication to the sheet metal according to the lubrication procedure includes applying a dry film lubricant in a machine-readable pattern; the method also includes scanning the metal part for defects and automatically adjusting the lubrication procedure based on the detected defects; the test sheet metal blank is a computer model of a physical sheet metal blank, and the test stamping process is a computer simulation of a stamping process, wherein the computer simulation generates the strain map; the test sheet metal blank is a physical piece of sheet metal, and the test stamping process physically deforms the test sheet metal blank, wherein the method includes inspecting the test sheet metal blank after the test stamping process, and generating the strain map based on the inspection of the test sheet metal blank after the test stamping process; the method also includes operating a blanking machine on the sheet metal, the blanking machine removing material from discrete lengths of sheet metal to form sheet metal blanks; before the blanking machine removes the material from discrete lengths of sheet metal to form sheet metal blanks, applying lubrication to the sheet metal according to the lubrication procedure; after the blanking machine removes the material from discrete lengths of sheet metal to form sheet metal blanks, applying lubrication to the sheet metal according to the lubrication procedure.

[0017] According to another form of the teachings of the present disclosure, a method for manufacturing a metal part includes: performing a computer simulation of a stamping process to be performed on a metal sheet blank, the computer simulation calculating a strain map of the metal sheet blank for the stamping process; generating a lubrication program based on the strain map, the lubrication program being configured to control a print head to apply lubrication to the metal sheet material so that the lubrication has a thickness that varies across the metal sheet material, the thickness being related to the strain map; applying lubrication to the metal sheet material according to the lubrication program; cutting the metal sheet material into a predetermined shape to define the metal sheet blank; and stamping the metal sheet blank to form a metal part.

[0018] According to a variation of the method that may be employed alone or in any combination: the lubrication program is configured to control a print head to apply a first thickness of lubrication to a first area of ​​the metal sheet material and a second thickness of lubrication to a second area of ​​the metal sheet material, the first thickness being thicker than the second thickness, wherein the first area of ​​the metal sheet material is associated with a strain map region having a higher strain than a strain map region associated with the second area of ​​the metal sheet material; the print head includes a plurality of print nozzles, each print nozzle being individually controlled by the lubrication program, wherein the method includes moving the metal sheet material past the print head while the print head remains stationary and applying lubrication to the metal sheet material according to the lubrication program.

[0019] According to another form of the teachings of the present disclosure, a system for lubricating a metal sheet to be formed into a metal part is provided. The system includes a printhead and at least one control module. The printhead includes a plurality of lubricant nozzles. Each of the plurality of lubricant nozzles can be individually controlled to selectively spray lubricant onto the metal sheet according to a lubrication program. At least one control module is configured to generate a lubrication program based on a strain map. The strain map is an output of a computer simulation of a stamping process to be performed on the metal sheet. At least one control module is configured to control the operation of the printhead to apply lubricant to the metal sheet according to the lubrication program.

[0020] Further areas of applicability will become apparent from the description provided herein.It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order that the present disclosure may be better understood, various forms of the present disclosure will now be described by way of example with reference to the accompanying drawings, in which:

[0022] Figure 1 is a schematic flow chart of a method of producing a metal part from a metal sheet according to the teachings of the present disclosure;

[0023] Figure 2is a schematic perspective view of a lubrication device according to the teachings of the present disclosure;

[0024] Figure 3 According to the teachings of this disclosure Figure 2 A schematic bottom view of a portion of a print head of a lubrication device;

[0025] Figure 4 is used for Figure 3 A schematic cross-sectional view of an example of a nozzle in a print head;

[0026] Figure 5 According to the teachings of this disclosure Figure 3 A schematic top view of a pixel lubrication spray pattern of a print head;

[0027] Figure 6 According to the teachings of this disclosure Figure 3 A top view of an example of a barcode lubrication spray pattern of a print head;

[0028] Figure 7 According to the teachings of this disclosure Figure 3 A top view of a second example of a barcode lubrication spray pattern of a print head;

[0029] Figure 8 is a top view of a strain map of a metal component according to the teachings of the present disclosure;

[0030] Fig. 9 is a schematic bottom view of a portion of a lubrication system according to another configuration of the teachings of the present disclosure;

[0031] 10 is a schematic bottom view of a portion of a lubrication system in accordance with yet another configuration of the teachings of the present disclosure.

[0032] 11 is a schematic side view of a portion of a lubrication system in accordance with yet another configuration of the teachings of the present disclosure.

[0033] 12 is a schematic side view of a lubrication system in accordance with yet another configuration of the teachings of the present disclosure.

[0034] 13 is a schematic top view of a lubrication system in accordance with yet another configuration of the teachings of the present disclosure.

[0035] 14 is a schematic top view of a lubrication system in accordance with another configuration of the teachings of the present disclosure; and

[0036] 15 is a schematic side view of a lubrication system in accordance with yet another configuration of the teachings of the present disclosure.

[0037] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. DETAILED DESCRIPTION

[0038] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0039] refer to Figure 1 , a flow chart and system for a method of manufacturing a metal component 110 is shown. The metal sheet material 114 is fed through a lubrication system 130, such as by rollers (not specifically shown, but may be similar to, for example, Figure 2 those shown in ).

[0040] In one form, the sheet metal material 114 may be unrolled from a metal coil 120. In one form, the sheet metal material 114 may be cut into predetermined discrete lengths from the coil 120 prior to being fed through the lubrication system 130 such that discrete rectangular flat sheets of metal are fed into the lubrication system 130. In another form, the lubrication system 130 acts on a continuous sheet of metal from the coil 120.

[0041] At the lubrication system 130, lubrication is applied to the sheet metal material 114. The application of lubrication is controlled by a control module 134, as described in more detail below. Although described herein as "one" control module 134, it should be understood that one or more control modules may be used.

[0042] After lubrication, the sheet metal material is fed to a feeder 118 or feeder machine, such as by rollers (not specifically shown, but may be similar to, for example, Figure 2 ). The blanking machine 118 performs a blanking operation to form a sheet metal blank 122. The sheet metal blank 122 is a predefined overall shape and may optionally include cutouts 124. The blanking operation produces scrap or offcuts 126, such as metal material removed to define the shape and any cutouts 124. The blanking operation may also cut metal material from the coil 120, such that the sheet metal blank 122 is a discrete piece of metal material that has not been cut before or after lubrication.

[0043] In the example provided, the sheet metal blank 122 is a flat sheet of material having a predefined shape. In alternative configurations not specifically shown, the sheet metal blank 122 may include a slight bend or an initial bend. In the specific example provided, the metal component 110 is a vehicle body or frame panel, and the cutout 124 is a rough opening corresponding to a door and / or window opening in the final metal component 110, although other types of metal components may be manufactured.

[0044] Although shown and described herein as lubricating the sheet metal material 114 prior to the blanking process of the blanking machine 118, in an alternative configuration not specifically shown, the lubrication system 130 may be after the blanking machine 118 so that lubricant is applied to the sheet metal blank 122 after being processed by the blanking machine 118 in a manner similar to that discussed below. In yet another configuration not specifically shown, a lubrication system similar to the lubrication system 130 may be included before and after the blanking machine 118 so that the lubrication applied before the blanking machine 118 may be dedicated to the blanking operation, and the lubrication applied after the blanking machine 118 may be dedicated to the subsequent stamping operation.

[0045] Additional references Figure 2 , the lubrication system 130 includes a control module 134 and a print head 210. The print head 210 communicates with the control module 134, and the control module 134 is configured to control the operation of the print head 210, as described in detail below. The lubrication system 130 may also optionally include a lubrication capture and recirculation system 214, which is configured to capture and reuse or recirculate excess lubrication. The lubrication capture and recirculation system 214 may be any suitable system and may include, for example, devices such as a pump (not specifically shown), a recirculation conduit 218, and a filter (not specifically shown).

[0046] In the example provided, the printhead 210 is stationary and the sheet metal material 114 is translated past the printhead 210 while the printhead 210 sprays lubricant onto the sheet metal material 114 as the sheet metal material 114 moves past. For example, the sheet metal material 114 may be translated by the roller 222, but other configurations may be used. In the example provided, the printhead 210 is located above the path of the sheet metal material 114 so that the printhead 210 sprays the lubricant onto the top surface of the sheet metal material 114. In alternative configurations such as shown in FIGS. 11 and 12, for example, the printhead 210 may be positioned below the path of the sheet metal material 114 to spray the lubricant onto the bottom surface of the sheet metal material 114, or, although not specifically shown, more than one printhead may be used so that one printhead sprays the top surface and another printhead sprays the bottom surface.

[0047] One or more sensors 226 may be in communication with control module 134 and configured to detect sheet metal material 114, such as detecting its position in the X and / or Y directions relative to, for example, printhead 210. Sensors 226 may also be configured to detect a width of sheet metal material 114.

[0048] Although the sheet metal material 114 is shown as translating horizontally, other orientations may be used. Although pairs of rollers 222 are shown, such that the sheet metal material 114 passes between two rollers 222 in each pair of rollers, other configurations may be used, such as rollers 222 located only below the sheet metal material 114.

[0049] Back to Figure 1 After lubrication 130 and blanking 118, the lubricated sheet metal blank 122 may optionally be stacked with other lubricated sheet metal blanks to form a stack of sheet metal blanks 138. The sheet metal blank 122 is then removed from the stack 138 and moved to a punch press 142. In an alternative configuration, the sheet metal blank 122 may enter the punch press 142 directly without being stacked.

[0050] In yet another alternative configuration, not specifically shown, the lubrication system 130 may be located after the stack of sheet metal blanks 138 and before the punch press 142 .

[0051] The punch press 142 performs punching operations on the sheet metal blank 122. These punching operations can punch the sheet metal blank 122 between dies (not specifically shown), which can form the sheet metal blank 122 into a three-dimensional shape. The punching operation can optionally remove additional scrap or offcuts 144. Although one punch press 142 is schematically shown, multiple punch presses can be used to achieve the final three-dimensional shape of the metal part 110.

[0052] refer to Figure 3 , the print head 210 includes a plurality of nozzles 310. Each nozzle 310 is connected to the control module 134 for electrical communication therewith and is configured to be controlled independently of each other nozzle 310. Thus, each nozzle 310 is individually addressable, such that the control module 134 is configured to independently activate and deactivate each nozzle 310 according to a lubrication program, as described in more detail below.

[0053] The print head 210 includes a first set of nozzles (i.e., nozzles 310 within the dashed area 314) connected to a lubrication source 318, which may include at least, for example, a reservoir (not specifically shown) and a pump (not specifically shown). In the example provided, the first set of nozzles 314 may be arranged in an array along the Y direction, while the metal sheet material 114 ( Figure 2 ) is configured to translate in the X direction relative to the print head 210, although other arrangements may be used. The print head 210 may optionally include a second set of nozzles 322 that may be arranged in a second array along the Y direction, although other arrangements may be used. The print head 210 may be configured to span the entire width (i.e., in the Y direction) of the metal sheet material 114 ( Figure 2 ).

[0054] In the example provided, the second set of nozzles 322 can be connected to a second lubrication source 326, which can optionally be separate from the first lubrication source 318. The first lubrication source 318 and the second lubrication source 326 can optionally supply different types of lubrication. In one form, the first lubrication source 318 provides a liquid lubricant, while the second lubrication source 326 provides a solid lubricant, such as a powder or dry film wax, for example. In an alternative configuration not specifically shown, both the first set of nozzles 314 and the second set of nozzles 322 can be connected to the same lubrication source. Although two arrays of nozzles 310 are shown, the nozzles 310 can be arranged in other configurations.

[0055] Nozzles 310 may be any suitable type of nozzles configured to be independently controlled and to print lubrication with an accuracy that provides lubrication pixels between 20 microns and 3,000 microns in size.

[0056] refer to Figure 4 , schematically illustrating an example of a nozzle 310 . Figure 4 The exemplary nozzle 310 is a piezoelectrically actuated nozzle, but other types of nozzles may be used. In some forms, this type of nozzle may be referred to as an ultrasonic atomizer. The exemplary nozzle 310 includes an orifice plate 410, an actuator 414, and a body 418. The body 418 and the orifice plate 410 cooperate to define a reservoir 422, which is configured to hold a certain volume of lubricant. The body 418 defines an inlet 426, which leads to the reservoir 422 and is configured to supply lubricant material M to the reservoir 422. The orifice plate 410 defines one or more holes 430. In the example provided, multiple holes 430 are shown, but in alternative forms, a single hole or more or fewer holes than shown may be used. The actuator 414 is a piezoelectric actuator configured to vibrate the orifice plate 410. The vibration of the orifice plate 410 causes the lubricant to be ejected from the nozzle 310 through the hole 430.

[0057] In some alternative forms, actuator 414 may be attached to body 418 separately from orifice plate 410, such as within reservoir 422, for example, and configured to generate acoustic pressure waves in the lubricant within reservoir 422. The acoustic pressure waves may cause lubricant to be ejected from nozzle 310 through orifice 430.

[0058] In other forms, nozzle 310 may be other types of printing nozzles known in the art. For example, nozzle 310 may be a piezoelectric jet nozzle, a thermal jet nozzle, a valve jet nozzle, or other inkjet nozzle capable of printing pixels between 20 microns and 3,000 microns in size.

[0059] Back to Figure 1 The control module 134 is configured to independently control each nozzle 310 based on the lubrication schedule 148 ( Figure 3 ) operation. To generate the lubrication program 148, a test stamping process 152 is performed on a test sheet metal blank. Based on the results of the test stamping process 152, a strain map 810 ( Figure 8 ). Based on the strain diagram 810 ( Figure 8 ) Generate lubrication program 148.

[0060] In one form, the test stamping process 152 is a simulated stamping process performed on a computer (not specifically shown) such that the test sheet metal blank is a computer model of the actual sheet metal blank 122. The test sheet metal blank is loaded into a computer program that performs a simulation (e.g., finite element analysis) of the stamping process on the test sheet metal blank (i.e., the computer model). The computer program generates a strain map from the simulation performed on the test sheet metal blank. The strain map 810 ( Figure 8 ) may include values ​​indicating strain at different locations along the test sheet metal blank. The strain map 810 may also optionally include other values, such as friction coefficient values, thickness values, locations of potential fractures, etc.

[0061] A computer (e.g., the same or different computer as the computer that generated strain map 810) can then generate a lubrication program based on strain map 810. For example, the lubrication program can be configured to provide a higher lubrication thickness to locations where strain map 810 indicates high strain levels. Additionally or alternatively, the lubrication program can be configured to provide a higher level of lubrication where the resulting material is thinner and / or where simulations predict that cracking may occur.

[0062] In one form, the lubrication procedure may reduce or eliminate the application of lubrication within a predetermined distance from the edge of the sheet metal blank 122 so that a less lubricated or no lubricated boundary 814 ( Figure 8 ).

[0063] In an alternative form, the test sheet metal blank can be a physical sheet metal blank (similar to the sheet metal blank 122), and the test stamping process 152 can include physically stamping the test sheet metal blank. The stamped test sheet metal blank can then be measured or scanned to generate a strain map 810. For example, the stamped test sheet metal blank can be physically measured with a tool, or scanned with a three-dimensional scanner (not shown), such as a laser scanner, a radar scanner, an optical scanner, or other suitable scanner. The measured values ​​can indicate strains at different locations along the test sheet metal blank. For example, the measured values ​​can determine the change in thickness and / or the location where the crack occurs. The measured values ​​associated with its position on the test sheet metal blank produce a strain map 810. The strain map 810 is then used to generate a lubrication program 148 in a manner similar to that described above with reference to the computer-simulated test stamping process 152.

[0064] In one form, the test stamping process may optionally include test runs (e.g., actual physical tests or computer simulated test runs) of both the stamping process and the blanking process such that the strain map 810 is based on the operation of both the blanking machine 118 and the punch press 142, and the lubrication program is based on both operations.

[0065] The control module 134 uses the lubrication program to control the selective activation of the nozzles 310 to apply lubrication to the actual sheet metal material 114 such that lubrication is applied non-uniformly across the sheet metal material 114 in a manner that correlates to the strain map 810 .

[0066] After one or more stamping operations, the metal part 110 may optionally be scanned 160 (e.g., an optical scanner, a laser scanner, etc.), and any defects may be used to modify the lubrication schedule to generate a new lubrication schedule 148 for use by the control module 134. In one form, machine learning may utilize the results of the scan 160 to automatically adjust the lubrication schedule.

[0067] refer to Figure 8 , shows an exemplary strain diagram 810 of a sheet metal blank 122 for the example provided. Figure 8 , the strain graph 810 and the sheet metal blank 122 are shown superimposed on discrete lengths of sheet metal material 114 for ease of understanding. Figure 8 In the diagram, different regions or strain levels are indicated by different shades or colors. Figure 8 A visual representation of a strain map is shown, but a strain map may simply be a set of data relating strain values ​​and their corresponding locations (e.g., coordinates) on the sheet metal blank 122. It should be understood that different applications will have sheet metal blanks of different sizes, shapes, and contours, and that strain maps for different applications will be different.

[0068] In one form, the lubrication program may be configured to apply lubrication to a first region 818 of the sheet metal material 114 according to a first thickness and to apply lubrication to a second region 822 of the sheet metal material 114 according to a second thickness, the first thickness being thicker than the second thickness. In one form, the first region 818 of the sheet metal material 114 is associated with a region of the strain map 810 having a higher strain than a region of the strain map 810 associated with the second region 822 of the sheet metal material 114. Any number of regions having different strain levels, and therefore different thicknesses or types of lubrication, may be used based on the resolution of the simulation or measurement and the resolution of the print head 210.

[0069] refer to Figure 5 , lubrication system 130( Figure 1 and Figure 2Another feature of the ) is that the control module can control the precise application of lubricant to produce lubricated pixels 510. Figure 5 In the example shown, lubrication is shown as shaded squares, while areas without lubrication are shown as blank squares. Although square pixels are shown, other shapes may be used, depending on the nozzle 310 ( Figure 3 and Figure 4 ) configuration, such as, for example, circular pixels. As discussed above, the size of the pixels ranges from 20 microns to 3,000 microns.

[0070] In one form, such as Figure 5 As shown in , pixels may alternate between lubricated pixels 510 and non-lubricated pixels over a given area of ​​the metal sheet material 114. In some applications, such a lubrication distribution may provide adequate lubrication coverage while using less lubrication than uniformly coating the entire area.

[0071] In another form, the lubrication program may be configured to change the spacing between pixels 510 and / or change the size of pixels 510 across the sheet metal material 114 based on the strain map 810 (ie, still within the range of 20 microns to 3000 microns).

[0072] In another form, Figure 6 and Figure 7 As shown in FIG. 6 , precise pixelated control over lubrication application can allow lubrication to be displayed as a barcode 610 ( Figure 6 ) or 710( Figure 7 ) is applied to certain locations of the metal sheet material 114. Figure 6 and Figure 7 A linear barcode and a two-dimensional barcode (e.g., a QR code) are shown separately, but other types of barcodes or scannable codes may be used. In one form, the lubricant may optionally be a material that fluoresces under a specific wavelength range (e.g., ultraviolet), and a scanner (not shown) utilizing that wavelength range may be used to scan the sheet metal material 114 (e.g., before stamping or after stamping).

[0073] The barcode 610 or 710 may include any suitable information. In one form, the barcode 610 or 710 may include a metal and / or lubrication batch number and / or date, but other information may be used. For example, the information may indicate a vehicle part number and / or manufacturing location, among other information. Although a machine scannable barcode is shown, other information may be printed in addition to or in lieu of a barcode, such as, for example, human readable text or symbols.

[0074] In the example provided, barcodes 610 and 710 are applied with a dry film lubricant, but other configurations may be used.

[0075] In another form, again referring to Figure 8 , the lubrication procedure can be configured to provide a less lubricated (or no lubrication) boundary 814 within a predefined distance from an edge 826 (e.g., a perimeter and / or an edge defining a cut) of the sheet metal blank 122. By providing less lubrication near the edge, the stacked sheet metal blanks 122 can be more easily separated.

[0076] Additionally, the precision printhead 210 and individual control of the nozzles 310 of the printhead 210 allow different sizes and shapes of sheet metal materials or blanks to be used with the same lubrication system 130 simply by changing the lubrication program.

[0077] refer to Fig. 9 , a second configuration of the lubrication system 130-2 is shown. Unless otherwise shown or described herein, the lubrication system 130-2 is similar to the lubrication system 130 ( Figures 1 to 3 ). Therefore, similar features are indicated by similar numbers, and only the differences will be explained in detail. Specifically, the lubrication system 130-2 includes a plurality of nozzles 310 that can be controlled individually and an array of nozzles 910 that cannot be controlled individually but are all controlled together.

[0078] In the example provided, the nozzles 910 are arranged approximately in the center of the path that the sheet metal material 114 will pass through, but other configurations may be used. The nozzles 910 all provide lubrication in uniform amounts simultaneously. The control module 134 may communicate with a valve 914 between the lubricant supply 326 and the nozzles 910. When the valve 914 is open, lubricant flows from all nozzles 910.

[0079] In the example provided, the lubricant supply 326 is separate from the lubricant supply 318, but other configurations may be used. In one form, the lubricant supplies 318, 326 provide the same type of lubricant. In an alternative form, the lubricant supplies 318, 326 provide different types of lubricants. In an alternative configuration, some of the nozzles 910 may have more holes or holes of different sizes so that different amounts of lubricant can be discharged from each nozzle 910 despite all nozzles operating simultaneously based on the condition of the valve 914.

[0080] The nozzles 910 may optionally be electrostatically charged to charge the lubricant exiting the nozzles 910 so as to be attracted to the metal sheet material 114. In one configuration, the individually controllable nozzles 310 are not electrostatically charged. In another configuration, the individually controllable nozzles 310 may be electrostatically charged.

[0081] In the example provided, the individually controllable nozzles 310 are arranged in an array (similar to Figure 310 and indicated by reference numeral 130-3, the individually controllable nozzles 310 may be positioned only across the path of the sheet metal material 114 at locations where the nozzles 910 are not configured to spray. For example, the nozzles 910 may be positioned to spray generally in the middle of the path, while the nozzles 310 are only located near the edges of the path.

[0082] Thus, when lubrication system 130-2 or 130-3 is used for sheet metal parts of different widths, different numbers of nozzles 310 can be selectively turned on or off to avoid overspray. Thus, lubrication system 130-2 or 130-3 can optionally provide lubrication for sheet metal parts of different widths, and lubrication can be provided as a uniform or non-uniform distribution. Alternatively, lubrication system 130-2 or 130-3 can provide reduced lubrication near the edge while providing a uniform or non-uniform distribution across the middle. In the case of lubrication system 130-3, the non-uniform distribution across the middle can be achieved by predetermined different numbers or sizes of holes between nozzles 910.

[0083] Referring to FIG. 11 , a portion of a lubrication system 130-4 is shown. Unless otherwise shown or described herein, the lubrication system 130-4 is similar to other lubrication systems of the present disclosure. Therefore, similar features are indicated by similar numbers, and only the differences will be explained in detail. Specifically, the lubrication system 130-4 is configured to spray upward from below the metal sheet material 114, and the lubrication system 130-4 includes a charging device 1110 that communicates with the control module 134. In other words, the positive Z direction shown is upward, and gravity acts in the opposite (negative Z) direction. In alternative forms not specifically shown, gravity can act in the positive X direction or the negative X direction or at an angle relative to the X and Z directions. In the example provided, the metal sheet material 114 moves in the positive X direction relative to the print head 210.

[0084] Although not shown, additional print heads (eg, upper print heads) may optionally be disposed above the metal sheet material 114 to coat the top surface thereof.

[0085] The charging device 1110 is configured to charge the lubricating particles as they pass through the air gap between the printhead 210 and the metal sheet material 114. In forms including an optional upper printhead, the upper printhead may optionally have or not have a corresponding charging device (not shown).

[0086] In the example provided, the charging device 1110 includes one or more plates 1114 that generate an electric field (schematically shown by opposite arrows between the plates 114) that is configured to charge the particles and is controlled by the control module 134. The plates 1114 can be coupled to the printhead 210, or can be separate therefrom and disposed between the printhead 210 and the metal sheet material 114. In the example provided, the charging device 1110 applies a positive charge to the particles. In another form, the charging device applies a negative charge to the particles. In one form, the charging device 1110 can charge the lubricating particles to a range of 10 to 200 kV.

[0087] Referring to FIG. 12 , a portion of a lubrication system 130-5 is shown. Unless otherwise shown or described herein, the lubrication system 130-5 is similar to other lubrication systems of the present disclosure. Therefore, similar features are indicated by similar numbers, and only the differences will be explained in detail. Specifically, the lubrication system 130-5 is configured to spray upward from below the metal sheet material 114, and the lubrication system 130-5 includes a charging device 1210 that communicates with the control module 134. In other words, the positive Z direction shown is upward, and gravity acts in the opposite (negative Z) direction. In alternative forms not specifically shown, gravity can act in the positive X direction or the negative X direction or at an angle relative to the X and Z directions. In the example provided, the metal sheet material 114 moves in the positive X direction relative to the print head 210.

[0088] Although not shown, an additional print head (ie, an upper print head) may optionally be disposed above the metal sheet material 114 to coat the top surface thereof.

[0089] The charging device 1210 is configured to charge the lubricant before the lubricant leaves the print head 210. In one form, the charging device 1210 is between the lubricant reservoir 1214 and the print head 210, such as, for example, within the lubrication recirculation system 214. In another form not specifically shown, the charging device 1210 is attached to the print head 210 or within the print head. In one form, the charging device 1210 can cause the charge carried by the lubricating particles to be in the range of 10 to 200 kV. In forms including an optional upper print head, the upper print head can optionally receive charged lubricant from the same charging device 1210 as the print head 210, or the upper print head can have a corresponding charging device (not shown) or can be configured not to spray charged lubricant.

[0090] 11 and 12, the lubrication system 130-4 or 130-5 can be configured so that the metal sheet material 114 can be optionally grounded or oppositely charged to attract charged lubricating droplets. Alternatively, the metal sheet material 114 can be optionally positioned between the external charging device 1122 and a grounded or oppositely charged electrode.

[0091] The control module 134 may be configured to control and selectively vary an external electric field (schematically shown by an arrow pointing in the positive Z direction) applied between the print head 210 and the metal sheet material 114. In one form, the applied electric field is in the range of 0 to 120 kV / m, and in some forms, more specifically between 30 to 120 kV / m.

[0092] In one form, the voltage applied by the charging device 1110 or 1210 (e.g., when the charging device 1110 or 1210 is mounted to or near the printhead 210) can be varied to selectively vary the electric field between the printhead 210 and the metal sheet material 114. For example, the charging device 1110 can generate an electric field between the printhead 210 and the metal sheet material 114, or if the charging device 1210 is mounted to the printhead 210, the charging device can charge the printhead 210 to generate an electric field between the printhead 210 and the metal sheet material 114.

[0093] In another form, the control module 134 may control the application of the external electric field via an optional external charging device 1122 or 1222. The external charging device 1122 or 1222 may be in addition to the charging device 1110 or 1210 and is not specifically configured to charge the lubricating particles. For example, in one form, the charging device 1122 or 1222 may be further away from the aperture 430 (at a position 100 m below the aperture 430) than the charging device 1110 or 1210. Figure 4 In contrast, the external charging device 1122 or 1222 generates an external electric field only in the gap between the print head 210 and the metal sheet material 114, through which the already charged particles pass.

[0094] The control module 134 can selectively change the external electric field to selectively change the speed of the charged lubricant particles flying toward the metal sheet material 114. Therefore, the speed of the lubricant particles can be controlled and changed without changing the actuator 414 ( Figure 4 ), which will also change the particle size of the ejected particles. In one form, the control module 134 can adjust the electric field based on the speed of the metal sheet material 114 and / or the distance between the print head 210 and the metal sheet material 114. For example, a stronger electric field can be used for faster speeds and / or greater distances of the metal sheet material 114.

[0095] Although the print head 210 is shown ejecting droplets perpendicular to the movement of the metal sheet material 114, other configurations may be used, such as at a non-perpendicular angle, for example.

[0096] Referring to FIG. 13 , a schematic top view of an alternative form of lubrication system 130 - 6 is shown. Unless otherwise shown or described herein, lubrication system 130 - 6 is similar to other lubrication systems of the present disclosure. Therefore, similar features are indicated by similar numbers, and only the differences will be explained in detail. In this example, one or more plates 1114 ( FIG. 11 ) are rings 1310, and the external charging device 1122 is also in the form of a ring 1314. In this example, the ring 1310 surrounds a single nozzle in the nozzles 310. In this example, the ring 1314 also surrounds a single nozzle in the nozzles radially outside the ring 1310, but other configurations may be used.

[0097] Referring to Figure 14, a schematic top view of an alternative form of lubrication system 130-7 is shown. Unless otherwise shown or described herein, lubrication system 130-7 is similar to other lubrication systems of the present disclosure. Therefore, similar features are indicated by similar numbers, and only the differences will be explained in detail. In this example, one or more charging plates 1114 are rings 1410, and the external charging device 1122 is also in the form of a ring 1414. In this example, the ring 1410 surrounds a plurality of nozzles 310. In this example, the ring 1414 also surrounds a plurality of nozzles radially outside the ring 1410, but other configurations may be used.

[0098] Referring to FIG. 15 , a non-limiting example of a lubrication system 130-8 is shown in which the print head ejects droplets in a direction that is not perpendicular to the movement of the metal sheet material 114. In this example, the droplets are ejected in the same direction as the movement of the metal sheet material 114, but other configurations may be used. Unless otherwise shown or described herein, the lubrication system 130-8 is similar to other lubrication systems of the present disclosure. Therefore, similar features are indicated with similar numbers, and only the differences will be explained in detail. In the example provided, the electric field generated by the external charging device 1122 changes the direction of the charged ejected droplets. The controller 134 can control the strength of the electric field generated by the external charging device 1122 to control the speed at which the droplets are redirected toward the metal sheet material 114. Although the droplets are shown to be charged by the external plate 1114, the material may alternatively be charged in the manner shown and described with reference to FIG. 12 .

[0099] 11 to 15 , when the printhead 210 is positioned on both sides (e.g., above and below) of the metal sheet material 114, the droplets on one side of the metal sheet material 114 may be charged with an opposite polarity to the droplets on the opposite side of the metal sheet material. In this way, the electric field generated by the external charging device 1122 drives the droplets from the two printheads 210 toward the metal sheet material 114.

[0100] Unless otherwise expressly indicated herein, all numerical values ​​indicating mechanical / thermal properties, composition percentages, dimensions and / or tolerances or other characteristics when describing the scope of the present disclosure should be understood to be modified by the word "about" or "approximately". Such modifications are desirable for a variety of reasons, including: industrial practice; material, manufacturing and assembly tolerances; and testing capabilities.

[0101] As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A or B or C), using a non-exclusive logical "or", and should not be construed to mean "at least one of A, at least one of B, and at least one of C."

[0102] In this application, the terms "controller" and / or "module" and / or "control module" may refer to, be part of, or include: an application-specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinatorial logic circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated, or group) that executes code; a memory circuit (shared, dedicated, or group) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality (e.g., an operational amplifier circuit integrator as part of a heat flux data module); or a combination of some or all of the above, such as in a system on a chip.

[0103] The term memory is a subset of the term computer-readable medium. The term computer-readable medium as used herein does not encompass transient electrical or electromagnetic signals propagated through a medium (such as on a carrier wave); therefore, the term computer-readable medium may be considered to be tangible and non-transitory. Non-limiting examples of non-transitory tangible computer-readable media are non-volatile memory circuits (such as flash memory circuits, erasable programmable read-only memory circuits, or mask read-only circuits), volatile memory circuits (such as static random access memory circuits or dynamic random access memory circuits), magnetic storage media (such as analog or digital tape or hard drives), and optical storage media (such as CDs, DVDs, or Blu-ray discs).

[0104] The apparatus and methods described in this application may be implemented partially or completely by a special-purpose computer, which is created by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program. The functional blocks, flow chart components, and other elements described above are used as software specifications, which can be translated into a computer program by routine work of a technician or programmer.

[0105] The description of the present disclosure is merely exemplary in nature, and therefore, variations that do not depart from the essence of the present disclosure are intended to be within the scope of the present disclosure. Such variations should not be regarded as departing from the spirit and scope of the present disclosure.

[0106] According to the present invention, a method for lubricating a material sheet includes moving the sheet along a first direction; operating a print nozzle to deposit lubricant on the sheet when the sheet moves along the first direction, wherein the print nozzle sprays the lubricant along a second direction transverse to the first direction and toward a first side of the sheet; charging the lubricant with a first charging device so that the lubricant sprayed from the print nozzle is in the form of charged droplets; operating a second charging device to apply an external electric field between the print nozzle and the sheet to attract the charged droplets to the sheet; and adjusting the velocity of the charged droplets by adjusting the strength of the external electric field.

[0107] In one aspect of the invention, the strength of the external electric field is controlled based on the speed at which the sheet moves along the first direction.

[0108] In one aspect of the invention, the printing nozzle is located below the sheet material.

[0109] In one aspect of the invention, the sheet material is a metallic material.

Claims

1. A method for lubricating a material sheet, the method comprising: moving the plate along a first direction; operating a print nozzle to deposit a lubricant on the sheet as the sheet moves along the first direction, wherein the print nozzle ejects the lubricant in a second direction transverse to the first direction and toward a first side of the sheet; charging the lubricant so that the lubricant ejected from the printing nozzle is in the form of charged droplets; as well as An external electric field is applied between the print nozzle and the sheet material to attract the charged droplets to the sheet material. 2 . The method of claim 1 , further comprising adjusting the velocity of the charged droplets by adjusting the external electric field. 3 . The method of claim 1 , wherein the strength of the external electric field is controlled based on a speed at which the sheet moves along the first direction. The method of claim 1 , wherein the lubricant is charged prior to being ejected from the print nozzle.

5. The method of claim 1, wherein the lubricant is charged as it is ejected from the print nozzle or immediately after being ejected from the print nozzle. The method of claim 1 , wherein the printing nozzle is located below the sheet material.

7. The method of claim 1, wherein the external electric field is in the range of 30 to 120 kV / m. The method according to claim 1 , wherein the charged droplets have a positive charge.

9. The method of claim 1, wherein the lubricant is charged by a first charging device and the external electric field is provided by a second charging device separate from the first charging device.

10. The method according to any one of claims 1 to 9, wherein the charge carried by the charged droplets is in the range of 10 to 200 kV.

11. A system for lubricating a metal sheet to be formed into a metal part, the system comprising: a printhead comprising a plurality of nozzles, each of the plurality of nozzles comprising an orifice plate, an actuator, and a body, the orifice plate and the body cooperating to define a reservoir configured to hold a lubricant, the actuator being configured to vibrate the lubricant in the reservoir to eject the lubricant as droplets through an aperture of the orifice plate; a first charging device configured to charge the lubricant; a second charging device configured to generate an external electric field between the print head and the metal plate; as well as A control module is configured to control the operation of the second charging device to selectively adjust the strength of the external electric field.

12. The system of claim 11, wherein the strength of the external electric field is selectively adjusted based on a speed at which the sheet moves along a first direction.

13. The system of claim 11, wherein the first charging device is configured to charge the lubricant before the lubricant is ejected from each nozzle.

14. The system of claim 11, wherein the first charging device is configured to charge the lubricant as it is ejected from each nozzle or immediately after it is ejected from each nozzle.

15. The system of claim 11, wherein the first charging device is configured to charge the lubricant in a range of 10 to 200 kV, and the external electric field in a range of 30 to 120 kV / m.

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