METHOD AND SYSTEM FOR ELECTROSTATIC CHARGING OF PUNCHING LUBRICANT FOR CONTROLLING DEPOSIT

Abstract

A method for lubricating a sheet of material involves moving the sheet along a first direction and operating a pressure nozzle to deposit a lubricant onto the sheet as the sheet moves along this first direction. The pressure nozzle ejects the lubricant in a second direction, perpendicular 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 pressure nozzle is in the form of charged droplets, and applying an external electric field between the pressure nozzle and the sheet to attract the charged droplets to the sheet.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Application No. 18 / 360,255, filed July 27, 2023, and entitled "METHOD AND SYSTEM FOR ELECTROSTATICALLY CHARGING STAMPING LUBRICANT TO CONTROL DEPOSITION," the contents of which are incorporated herein by reference in their entirety. FIELD OF TECHNOLOGY

[0002] The present disclosure relates to a method and system for lubricating and forming a metal component from sheet metal. GENERAL STATE OF THE ART

[0003] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0004] Some mass-produced metal components, such as vehicle body panels, may begin as a coil of sheet metal. The coil is typically continuously unwound while being cut into discrete, flat sheet metal blanks. The sheet metal blank is typically a discrete, flat sheet of metal that has a predetermined length and shape. Each sheet metal blank is then coated with a uniform thickness of a lubricant before being moved to a stamping press line or stacked for storage until ready to be moved to the stamping press line. The stamping press line typically includes one or more stamping presses configured to form the flat sheet metal blank into a three-dimensional metal component. Some stamping presses also remove small amounts of sheet metal during the stamping process.

[0005] The lubricant is typically applied to the sheet metal blank in a uniform thickness across its entire length and width, without consideration of the stamping process. Furthermore, the lubricant application systems currently in use typically result in excessive lubrication consumption and overspray, requiring complicated and expensive collection and recycling technologies. Additionally, stacking sheet metal blanks that are fully and uniformly lubricated can result in the lubrication being squeezed out of the edges. This squeezed-out lubrication can cause the stacked sheet metal blanks to stick together, which can make it difficult to remove an individual sheet metal blank from the stack, such as with a robotic arm.Accidentally loading two stuck-together sheet metal blanks into the stamping press can damage the press and slow production. Furthermore, excessive lubrication can complicate cleaning, pretreating, and painting the metal components after stamping.

[0006] The present disclosure addresses these and other problems associated with traditional processes and apparatus for lubricating and punching sheet metal. SUMMARY

[0007] This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.

[0008] In one form consistent with 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 pressure nozzle to deposit a lubricant onto the sheet as the sheet moves along the first direction. The pressure 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 such that the lubricant ejected from the pressure nozzle is in the form of charged droplets, and applying an external electric field between the pressure nozzle and the sheet to attract the charged droplets to the sheet.

[0009] According to variations of this method, which can be used individually or in any combination: the method further includes adjusting a velocity of the charged droplets by adjusting the external electric field; controlling a strength of the external electric field based on a speed of the sheet moving along the first direction; the sheet is a metal material; the lubricant is charged before it is ejected from the print nozzle; the lubricant is charged while it is ejected or immediately after it is ejected from the print nozzle; the print nozzle is located below the sheet; the external electric field is in the range of 30-120 kV / m; the charged droplets are charged with a positive charge; the positive charge is in the range of 10-200 kV; the charged droplets are charged to within the range of 10-200 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;

[0010] In another form consistent with 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 pressure nozzle to deposit a lubricant onto the sheet as the sheet moves along the first direction. The pressure 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 such that the lubricant ejected from the pressure nozzle is in the form of charged droplets, operating a second charging device to apply an external electric field between the pressure nozzle and the sheet to attract the charged droplets to the sheet, and adjusting a velocity of the charged droplets by adjusting a strength of the external electric field.

[0011] According to variations of this method, which can be used individually or in any combination: the strength of the external electric field is controlled based on a speed of the sheet moving along the first direction; the printing nozzle is located below the sheet.

[0012] In yet another form consistent with the teachings of the present disclosure, a system for lubricating sheet metal to be formed into a metal component includes a printhead, a first charging device, a second charging device, and a control module. The printhead includes a plurality of nozzles. Each nozzle 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 configured to hold lubricant. The actuator is configured to vibrate the lubricant in the reservoir to eject the lubricant as droplets through an orifice of the orifice plate. The first charging device is configured to electrically charge the lubricant. The second charging device is configured to create an external electric field between the printhead and the sheet metal.The control module is configured to control operation of the second charging device to selectively adjust a strength of the external electric field.

[0013] According to variations of this system, which may be used individually or in any combination: the control module is configured to selectively adjust the strength of the external electric field based on a speed of the sheet moving along a first direction; the first charging device is configured to electrically charge the lubricant before the lubricant is ejected from the print nozzle; the first charging device is configured to electrically charge the lubricant while it is being ejected or immediately after it is ejected from the print nozzle; the first charging device is configured to electrically charge the lubricant in the range of 10-200 kV and the external electric field is in the range of 30-120 kV / m.

[0014] In one form consistent with the teachings of the present disclosure, a method for manufacturing a metal component is provided. The method includes performing a test stamping process on a test sheet metal blank, generating a stress map of the test sheet metal blank for the test stamping process, generating a lubrication program based on the stress map, applying lubrication to the metal sheet according to the lubrication program, and stamping the metal sheet to form the metal component. The lubrication program is configured to control a lubrication system to apply lubrication to the metal sheet in a non-uniform distribution across the metal sheet. The non-uniform distribution correlates with the stress map.

[0015] According to variations of this method, which may be used individually or in any combination: the lubrication is applied by a print head including a plurality of print nozzles, each print nozzle being individually controlled by the lubrication program; the method further includes linearly moving the metal sheet while the print head applies the lubrication to the metal sheet; the lubrication program is configured to apply the lubrication according to a first thickness to a first region of the metal sheet and to apply the lubrication according to a second thickness to a second region of the metal sheet, wherein the first thickness is thicker than the second thickness; the first region of the metal sheet correlates to a region of the stress map having a higher stress than a region of the stress map correlated to the second region of the metal sheet;the printhead is configured to apply lubrication pixels to the metal sheet such that a size of each smear pixel is 20 micrometers to 3,000 micrometers; the lubrication program is configured to: change a spacing between the pixels or change the size of the pixels or change both the spacing between the pixels and the size of the pixels; the plurality of print nozzles includes a first subset of print nozzles and a second subset of print nozzles, wherein applying lubrication to the metal sheet includes 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 is configured to apply less lubrication near edges of a metal sheet blank;includes applying the lubrication to the metal sheet according to the lubrication program applying a dry film lubricant in a machine-readable pattern; the method further includes scanning the metal component for defects and automatically adjusting the lubrication program based on detected defects; the test metal sheet blank is a computer model of a physical metal sheet blank and the test punching process is a computer simulation of a punching process, wherein the computer simulation generates the stress map; the test metal sheet blank is a physical piece of metal sheet and the test punching process physically deforms the test metal sheet blank, the method includes inspecting the test metal sheet blank after the test punching process and the stress map is generated based on the inspection of the test metal sheet blank after the test punching process;The method further includes operating a stamping machine on the metal sheet, wherein the stamping machine removes material from a discrete length of the metal sheet to form a sheet metal blank; applying the lubrication to the metal sheet according to the lubrication program prior to the stamping machine removing the material from the discrete length of the metal sheet to form the sheet metal blank; applying the lubrication to the metal sheet according to the lubrication program after the stamping machine removing the material from the discrete length of the metal sheet to form the sheet metal blank.

[0016] In another form consistent with the teachings of the present disclosure, a method of manufacturing a metal component includes: performing a computer simulation of a stamping process to be performed on a sheet metal blank, the computer simulation calculating a stress map of the sheet metal blank for the stamping process; generating a lubrication program based on the stress map, the lubrication program configured to control a print head for applying lubrication to the sheet metal material such that the lubrication has a thickness that varies across the sheet metal material, the thickness being correlated to the stress map; applying lubrication to the sheet metal material according to the lubrication program; cutting the sheet metal material into a predetermined shape to define the sheet metal blank; and stamping the sheet metal blank to form the metal component.

[0017] According to variations of this method, which may be used individually or in any combination: the lubrication program is configured to control the print head to apply a first thickness of lubrication to a first region of the sheet metal material and to apply a second thickness of lubrication to a second region of the sheet metal material, wherein the first thickness is thicker than the second thickness and wherein the first region of the sheet metal material correlates to a region of the stress map having a higher stress than a region of the stress map correlating to the second region of the sheet metal material;the printhead includes a plurality of print nozzles, each print nozzle being individually controlled by the lubrication program, and wherein the method includes moving the sheet metal material past the printhead while the printhead remains stationary and applies the lubrication to the sheet metal material according to the lubrication program;

[0018] According to another form consistent with the present disclosure, a system for lubricating sheet metal to be formed into a metal component is provided. The system includes a printhead and at least one control module. The printhead includes a plurality of lubricant nozzles. Each lubricant nozzle of the plurality of lubricant nozzles is individually controllable to selectively eject lubricant onto the sheet metal according to a lubrication program. The at least one control module is configured to generate the lubrication program based on a stress map. The stress map is an output of a computer simulation of a stamping process to be performed on the sheet metal. The at least one control module is configured to control operation of the printhead to apply the lubricant to the sheet metal according to the lubrication program.

[0019] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. DRAWINGS

[0020] For a full understanding of the disclosure, various forms thereof will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a schematic flow diagram of a method for producing a metal component from sheet metal in accordance with the teachings of the present disclosure; Fig. 2 is a schematic view of a lubricating device in accordance with the teachings of the present disclosure; Fig. 3 is a schematic bottom view of a portion of a print head of the lubricator of Fig. 2 in accordance with the teachings of the present disclosure; Fig. 4 is a schematic cross-sectional view of an example of a nozzle for use in the printhead of Fig. 3; Fig. 5 is a schematic plan view of an example of a pixel smear spray pattern from the printhead of Fig. 3 in accordance with the teachings of the present disclosure; Fig. 6 is a plan view of an example of a barcode smear spray pattern from the print head of Fig. 3 in accordance with the teachings of the present disclosure; Fig. Figure 7 is a plan view of a second example of a barcode smear spray pattern from the printhead of Fig. 3 in accordance with the teachings of the present disclosure; Fig. 8 is a plan view of a stress map of a metal component in accordance with the teachings of the present disclosure; Fig. 9 is a schematic bottom view of a portion of a lubrication system of another configuration in accordance with the teachings of the present disclosure; Fig. 10 is a schematic bottom view of a portion of a lubrication system of yet another configuration in accordance with the teachings of the present disclosure; Fig. 11 is a schematic side view of a lubrication system of yet another configuration in accordance with the teachings of the present disclosure; Fig. 12 is a schematic side view of a lubrication system of yet another configuration in accordance with the teachings of the present disclosure; Fig. 13 is a schematic plan view of a lubrication system of yet another configuration in accordance with the teachings of the present disclosure; Fig. 14 is a schematic plan view of a lubrication system of another configuration in accordance with the teachings of the present disclosure; and Fig. 15 is a schematic side view of a lubrication system of yet another configuration in accordance with the teachings of the present disclosure.

[0021] The drawings described in this document are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way. DETAILED DESCRIPTION

[0022] 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 corresponding reference characters indicate like or corresponding parts and features throughout the drawings.

[0023] With reference to Fig. 1 is a flow diagram of a method and system for manufacturing a metal component 110. Sheet metal material 114 is guided through a lubrication system 130, such as rollers (which are not specifically shown but may, for example, be similar to those shown in Fig. 2 are shown).

[0024] In one form, the sheet metal material 114 may be unwound from a roll 120 of metal. In one form, the sheet metal material 114 may be cut from the roll 120 into predetermined discrete lengths before 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 operates on the continuous sheet of metal from the roll 120.

[0025] At the lubrication system 130, lubrication is applied to the sheet metal material 114. The application of the lubrication is controlled by a control module 134, which is described in more detail below. While "one" control module 134 is described herein, it is understood that one or more control modules may be used.

[0026] After lubrication, the sheet metal material is fed into a punch 118 or punching machine, such as by rollers (which are not specifically shown but may, for example, be similar to those used in Fig. 2). The puncher 118 performs punching operations to form a sheet metal blank 122. The sheet metal blank 122 is a predefined overall shape and may optionally include recesses 124. The punching operation generates scrap or waste 126, such as material removed to define the shape and any recesses 124. The punching operation may also separate the metal stock from the roll 120 so that the sheet metal blank 122 is a discrete piece of metal stock, unless already separated before or after lubrication.

[0027] In the example provided, the sheet metal blank 122 is a flat sheet having a predefined shape. In an alternative configuration not specifically shown, the sheet metal blank 122 may include small or initial bends. In the specific example provided, the metal component 110 is a vehicle body or frame panel, and the recesses 124 are openings corresponding to door and / or window openings in the final metal component 110, although other types of metal components may be fabricated.

[0028] While this document describes lubricating the sheet metal stock 114 prior to the punching process of punch 118, in an alternative configuration not specifically illustrated, the lubrication system 130 may be located downstream of punch 118 so that lubrication is applied in a manner similar to that described below, but after the sheet metal blank 122 is processed by punch 118. In yet another configuration not specifically illustrated, the lubrication system 130, similar to lubrication system 130, may be included before and after punch 118 so that the lubrication applied before punch 118 may be specific to the punching operation, and the lubrication applied after punch 118 may be specific to subsequent stamping operations.

[0029] With additional reference to Fig. 2, the lubrication system 130 includes the control module 134 and a printhead 210. The printhead 210 is in communication with the control module 134, and the control module 134 is configured to control the operation of the printhead 210, as described in detail below. The lubrication system 130 may also optionally include a lubrication collection and return system 214 configured to capture and reuse or recycle excess lubrication. The lubrication collection and return system 214 may be any suitable system and may include devices such as, for example, pumps (not illustrated), return lines 218, and filters (not specifically illustrated).

[0030] 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 ejects 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 rollers 222, although other configurations may be used. In the example provided, the printhead 210 is located over the path of the sheet metal material 114, such that the printhead 210 sprays lubricant onto a top surface of the sheet metal material 114. In an alternative configuration, such as those described, for example, in Fig. 11 and Fig. 12, the print head 210 may be positioned beneath the path of the sheet metal material 114 to spray lubricant onto the underside surface of the sheet metal material 114, or, while not specifically shown, more than one print head may be used such that one sprays the topside surface and another sprays the bottomside surface.

[0031] One or more sensors 226 may be in communication with the 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 the print head 210. The sensors 226 may also be configured to detect the width of the sheet metal material 114.

[0032] While the sheet metal material 114 is illustrated being translated horizontally, other orientations may be used. While pairs of rollers 222 are illustrated such that the sheet metal material 114 passes through two rollers 222 of each pair, other configurations may be used, such as rollers 222 located only beneath the sheet metal material 114.

[0033] Returning to Fig. 1, after lubrication 130 and deburring 118, the lubricated sheet metal blank 122 may optionally be stacked with other lubricated sheet metal blanks to form a stack 138 of sheet metal blanks. The sheet metal blank 122 is then removed from the stack 138 and moved into a punch press 142. In an alternative configuration, the sheet metal blank 122 may be advanced directly to the punch press 142 without being stacked.

[0034] In yet another alternative configuration, not specifically illustrated, the lubrication system 130 may be located behind the stack 138 of sheet metal blanks and in front of the punch press 142.

[0035] The punch press 142 performs punching operations on the sheet metal blank 122. These punching operations may press the sheet metal blank 122 between dies (not specifically shown) that may form the sheet metal blank 122 into three-dimensional shapes. The punching operations may optionally remove additional scrap or waste 144. While one punch press 142 is illustrated schematically, a variety of punch presses may be used to achieve the final three-dimensional shape of the metal component 110.

[0036] With reference to Fig. 3, the printhead 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 any other nozzle 310. Thus, each nozzle 310 is individually controllable, so that the control module 134 is configured to independently turn each nozzle 310 on and off according to a lubrication program, which is described in more detail below.

[0037] The printhead 210 includes a first set of nozzles (i.e., the nozzles 310 within the dashed region 314) connected to a lubrication source 318, which may include, for example, at least one reservoir (not specifically shown) and a pump (not specifically shown). In the example provided, a first set of nozzles 314 may be arranged in an array along the Y-direction while the sheet metal material 114 ( Fig. 2) is configured to be translated relative to the print head 210 in the X-direction, 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 print the entire width (i.e., in the Y-direction) of the sheet metal material 114 ( Fig. 2) to span.

[0038] In the example provided, the second set of nozzles 322 may be connected to a second lubrication source 326, which may optionally be separate from the first lubrication source 318. The first lubrication source 318 and the second lubrication source 326 may optionally supply different types of lubrication. In one form, the first lubrication source 318 provides a liquid lubricant, and the second lubrication source 326 provides a solid lubricant, such as, for example, a powder or a dry film wax. In an alternative configuration not specifically shown, both the first set of nozzles 314 and the second set of nozzles 322 may be connected to the same lubrication source. While two arrays of nozzles 310 are illustrated, the nozzles 310 may be arranged in other configurations.

[0039] The nozzles 310 may be any suitable type of nozzle configured to be independently controlled and to print lubrication with precision, providing lubrication pixels ranging in size from 20 microns to 3,000 microns.

[0040] With reference to Fig. 4, an example of a nozzle 310 is schematically illustrated. The exemplary nozzle 310 of Fig. 4 is a piezoelectrically actuated nozzle, although 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 capable of holding a volume of lubricant. The body 418 defines an inlet 426 open to the reservoir 422 and configured to supply lubricant material M to the reservoir 422. The orifice plate 410 defines one or more passages 430. In the example provided, a plurality of passages 430 are illustrated; in an alternative form, a single passage or more or fewer passages than shown may be used. The actuator 414 is a piezoelectric actuator configured to vibrate the passage plate 410.The vibration of the passage plate 410 causes the lubricant to be ejected from the nozzle 310 through the passages 430.

[0041] In some alternative forms, the actuator 414 may be mounted separately from the orifice plate 410 on the body 418, such as within the reservoir 422, for example, and configured to generate acoustic pressure waves in the lubricant located within the reservoir 422. The acoustic pressure waves may cause the lubricant to be ejected from the nozzle 310 through the orifices 430.

[0042] In still other forms, the nozzles 310 may be other types of printing nozzles known in the art. For example, the nozzles 310 may be piezoelectric jet nozzles, thermal jet nozzles, valve jet nozzles, or other inkjet nozzles capable of printing pixels between 20 micrometers and 3,000 micrometers in size.

[0043] Returning to Fig. 1, the control module 134 is configured to control the operation of each nozzle 310 ( Fig. 3) based on a lubrication program 148. To generate the lubrication program 148, a test punching process 152 is performed on a test metal sheet blank. Based on the results of the test punching process 152, a stress map 810 ( Fig. 8). The lubrication program 148 is generated based on the load map 810 ( Fig. 8) is generated.

[0044] In one form, the test punching process 152 is a simulated punching 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 punching process on the test sheet metal blank (i.e., the computer model). The computer program generates a stress map from the simulation performed on the test sheet metal blank. The stress map 810 ( Fig. 8) may include values ​​that may indicate stress at various locations along the test metal sheet blank. The stress map 810 may optionally also include other values, such as a coefficient of friction values, thickness values, and locations for potential tearing, among others.

[0045] A computer (e.g., the same computer or a different computer than the one that generated the stress map 810) may then generate the lubrication program based on the stress map 810. For example, the lubrication program may be configured to provide greater thicknesses of lubrication at locations where the stress map 810 indicates higher levels of stress. Additionally or alternatively, the lubrication program may be configured to provide higher levels of lubrication where the resulting material is thinner and / or where the simulation predicts that cracking may occur.

[0046] In one form, the lubrication program may reduce or prevent lubrication from being applied within a predetermined distance from the edges of the sheet metal blank 122, such that a boundary 814 ( Fig. 8) results from less or no lubrication.

[0047] In an alternative form, the test sheet metal blank may be a physical sheet metal blank (similar to sheet metal blank 122), and the test stamping process 152 may involve physically stamping the test sheet metal blank. The stamped test sheet metal blank may then be measured or scanned to generate the stress map 810. For example, the stamped test sheet metal blank may be physically measured or scanned with three-dimensional scanners (not shown), such as laser scanners, radar scanners, optical scanners, or other suitable scanners. The measurements may indicate stress at different locations along the test sheet metal blank. For example, the measurements may measure changes in thickness and / or locations where cracking has occurred. The measured values, correlated with their locations on the test sheet metal blank, result in the stress map 810.The stress map 810 is then used to generate the lubrication program 148 in a manner described above with respect to the computer-simulated test punching process 152.

[0048] In one form, the test punching process optionally includes test runs (e.g., physical tests or computer-simulated test runs) of both the punching process and the punching process, such that the stress map 810 is based on the operation of both the punch 118 and the punch press 142, and the lubrication program is based on both operations.

[0049] The control module 134 uses the lubrication program to selectively activate the nozzles 310 to apply the lubrication to the actual sheet metal material 114 such that the lubrication is not applied uniformly across the sheet metal material 114 in a manner that correlates with the stress map 810.

[0050] The metal component 110 can be scanned 160 after one or more stamping operations (e.g., optical scanners, laser scanners, etc.), and any defects can be used to modify the lubrication program to generate a new lubrication program 148 for the control module 134. In one form, the result of the scan 160 can be used through machine learning to automatically adjust the lubrication program.

[0051] With reference to Fig. 8 illustrates an exemplary stress map 810 for the sheet metal blank 122 of the provided example. In Fig. 8, the stress map 810 and the sheet metal blank 122 are illustrated superimposed over a discrete length of the sheet metal material 114 for easy understanding. In Fig. 8, different regions or levels of stress are indicated by different shades or colors. While Fig. 8 shows a visual representation of a stress map, the stress map may simply be a data set correlating with the stress values ​​and their locations (e.g., coordinates) on the sheet metal blank 122. It should be understood that different applications have sheet metal blanks with different sizes, shapes, and contours, and that the stress map will be different for different applications.

[0052] In one form, the lubrication program may be configured to apply lubrication according to a first thickness to a first region 818 of the sheet metal material 114 and to apply the lubrication according to a second thickness to a second region 822 of the sheet metal material 114, wherein the first thickness is thicker than the second thickness. In one form, the first region 818 of the sheet metal material 114 correlates with a region of the stress map 810 that has a higher stress than a region of the stress map 810 that correlates with the second region 822 of the sheet metal material 114. Based on the resolution of the simulation or measurements and the resolution of the printhead 210, any number of regions having different stress levels and, consequently, different lubrication thicknesses or types may be applied.

[0053] With reference to Fig. 5, another feature of the lubrication system 130 ( Fig. 1 and Fig. 2) that the control module can control precise application of the lubricant to create lubrication pixels 510. In the Fig. In the example shown in Figure 5, the lubrication is illustrated as dark squares and areas without lubrication are illustrated as light squares. While square pixels are illustrated, depending on the design of the nozzles 310 ( Fig. 3 and Fig. 4) Other shapes may be used, such as rounded pixels. As discussed above, the pixels have a size in the range of 20 micrometers to 3,000 micrometers.

[0054] In a form and as in Fig. As illustrated in Figure 5, the pixels alternate between lubricated pixels 510 and unlubricated pixels over a given area of ​​the metal sheet material 114. In some applications, such a distribution of lubrication may provide adequate lubrication coverage while using less lubrication than if the entire region were coated uniformly.

[0055] In another form, the lubrication program may be configured to change the spacing between the pixels 510 and / or change the size of the pixels 510 (ie, still within the range of 20 micrometers to 3,000 micrometers) across the sheet metal material 114 based on the stress map 810.

[0056] In another in the Fig. 6 and Fig. 7, the precise pixel-based control of the application of lubrication may allow the lubrication to be applied at specific locations on the sheet metal material 114 in the form of a barcode 610 ( Fig. 6) or 710 ( Fig. 7) is applied. Fig. 6 and Fig. 7 illustrate a linear barcode and a 2D barcode (e.g., QR code), respectively, but other types of barcodes or scannable codes may be used. In one form, the lubrication may optionally be a material that fluoresces under a specific wavelength range (e.g., ultraviolet), and a scanner (not shown) that utilizes this wavelength range may be used to scan the sheet metal material 114 (e.g., before and after stamping).

[0057] 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 data, although other information may be used. For example, the information may indicate, among other information, a vehicle part number and / or a manufacturing location. While machine-scannable barcodes are shown, other information may be printed in addition to or in place of a barcode, such as human-readable symbols.

[0058] In the examples provided, the 610 and 710 barcodes are applied using a dry film lubricant, although other configurations can be used.

[0059] In another form and with reference to Fig. 8. The lubrication program may be configured to provide the boundary 814 with less lubrication (or no lubrication) within a predefined distance from the edges 826 (e.g., the perimeter and / or the edges defining the recesses) of the sheet metal blank 122. By providing less lubrication near the edges, it may be easier to separate the stacked sheet metal blanks 122.

[0060] In addition, the precise print head 210 and the individual control of the nozzles 310 of the print head 210 allow different sizes and shapes of sheet metal material or blanks to be used with the same lubrication system 130 by simply changing the lubrication program.

[0061] With reference to Fig. 9 illustrates a lubrication system 130-2 of a second construction. The lubrication system 130-2 is similar to the lubrication system 130 ( Fig. 1-3) are similar unless otherwise shown or described herein. Accordingly, similar features are indicated by similar numbers, and only differences will be explained in detail. In particular, the lubrication system 130-2 includes a plurality of nozzles 310 that are individually controllable and an array of nozzles 910 that are not individually controllable, but instead are all controlled together.

[0062] In the example provided, the nozzles 910 are generally located in the center of the path along which the sheet metal material 114 passes, although other configurations may be used. The nozzles 910 all provide a uniform amount of lubrication at the same time. The control module 134 may be in communication with a valve 914 between the lubricant supply 326 and the nozzles 910. When the valve 914 is open, the lubricant flows from all of the nozzles 910.

[0063] In the example provided, lubricant supply 326 is separate from lubricant supply 318, although other configurations may be used. In one form, lubricant supplies 318, 326 provide the same type of lubricant. In an alternative form, lubricant supplies 318, 326 provide different types of lubricant. In an alternative configuration, some of the nozzles 910 may have more or differently sized passages so that different amounts of lubricant exit each nozzle 910 based on the condition of valve 914, even though all nozzles are operating simultaneously.

[0064] The nozzles 910 can optionally be electrostatically charged to charge the lubricant exiting the nozzles 910 so that it is attracted to the sheet metal material 114. In one configuration, the individually controllable nozzles 310 are not electrostatically charged. In another configuration, the individually controllable nozzles 310 can be electrostatically charged.

[0065] In the example provided, the individually controllable nozzles 310 can be arranged in an array (similar Fig. 3) be arranged over the entire width of the path of the sheet metal material 114. In an alternative configuration, which is shown in Fig. 10 and designated by reference numeral 130-3, the individually controllable nozzles 310 may be located only over the path of the sheet metal material 114, with the nozzles 910 not configured to spray. For example, the nozzles 910 may be positioned to spray generally in the center of the path, while the nozzles 310 may be located only near the edges of the path.

[0066] As a result, a different number of nozzles 310 can be selectively turned on or off to prevent overspray when the lubrication system 130-2 or 130-3 is used for different widths of sheet metal components. Thus, the lubrication system 130-2 or 130-3 can optionally provide lubrication for different widths of the sheet metal and can provide the lubrication as a uniform or non-uniform distribution. Alternatively, the lubrication system 130-2 or 130-3 can provide reduced lubrication near the edges while providing either a uniform or non-uniform distribution over the center. In the case of the lubrication system 130-3, a non-uniform distribution over the center can be achieved with predetermined different numbers or sizes of passages among the nozzles 910.

[0067] With reference to Fig. 11 illustrates a portion of a lubrication system 130-4. The lubrication system 130-4 is similar to the other lubrication systems of the present disclosure unless otherwise shown or described herein. Accordingly, similar features are indicated by similar numbers, and only differences will be discussed in detail. In particular, the lubrication system 130-4 is configured to spray upward from beneath the sheet metal material 114, and the lubrication system 130-4 includes a charging device 1110 in communication with the control module 134. In other words, the positive Z direction shown is upward, and gravity acts in the opposite direction (negative Z direction). In an alternative form not specifically shown, gravity may act in the positive or negative X direction, or at an angle relative to the X and Z directions.In the example provided, the sheet metal material 114 moves in the positive X direction relative to the print head 210.

[0068] While not shown, an additional print head (e.g., top print head) may optionally be disposed over the metal sheet material 114 to spray the top surface thereof.

[0069] The charging device 1110 is configured to electrically charge the lubricating particles as they traverse the air gap between the printhead 210 and the sheet metal material 114. In the form in which the optional upper printhead is included, the upper printhead may or may not optionally include a corresponding charging device (not shown).

[0070] In the provided example, the charging device 1110 includes one or more plates 1114 that create an electric field (schematically illustrated by the opposing arrows between the plates 114) configured to charge the particles and controlled by the control module 134. The plates 1114 may be coupled to the printhead 210 or may be separate and disposed between the printhead 210 and the sheet metal material 114. In the provided example, 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 may charge the lubricating particles to a charge in the range of 10-200 kV.

[0071] With reference to Fig. 12 illustrates a portion of a lubrication system 130-5. The lubrication system 130-5 is similar to the other lubrication systems of the present disclosure unless otherwise shown or described herein. Accordingly, similar features are indicated by similar numbers, and only differences will be discussed in detail. In particular, the lubrication system 130-5 is configured to spray upward from beneath the sheet metal material 114, and the lubrication system 130-5 includes a charging device 1210 in communication with the control module 134. In other words, the positive Z direction shown is upward, and gravity acts in the opposite direction (negative Z direction). In an alternative form not specifically shown, gravity may act in the positive or negative X direction, or at an angle relative to the X and Z directions.In the example provided, the sheet metal material 114 moves in the positive X direction relative to the print head 210.

[0072] While not shown, an additional print head (i.e., top print head) may optionally be disposed over the sheet metal material 114 to spray the top surface thereof.

[0073] The charging device 1210 is configured to electrically charge the lubricant before it exits the printhead 210. In one form, the charging device 1210 is located between a lubrication reservoir 1214 and the printhead 210, such as, for example, within the lubrication return system 214. In another form, not specifically shown, the charging device 1210 is attached to or within the printhead 210. In one form, the charging device 1210 can charge the lubrication particles in the range of 10-200 kV. In the form in which the optional upper printhead is included, the upper printhead can optionally receive charged lubrication from the same charging device 1210 as the printhead 210, or the upper printhead can have a corresponding charging device (not shown) or be configured not to spray charged lubricant.

[0074] With reference to both Fig. 11 and 12, the lubrication system 130-4 or 130-5 may be configured such that the sheet metal material 114 may optionally be grounded or oppositely charged to attract the charged lubricant droplets. Alternatively, the sheet metal material 114 may optionally be positioned between the external charging device 1122 and a grounded or oppositely charged electrode.

[0075] The control module 134 may be configured to control and selectively vary an external electric field (schematically illustrated by the arrows pointing in the positive Z direction) applied between the print head 210 and the sheet metal material 114. In one form, this electric field is applied in the range of 0-120 kV / m, and in some forms, more specifically, between 30-120 kV / m.

[0076] In one form, the voltage applied by the charging device 1110 or 1210 (e.g., if the charging device 1110 or 1210 is mounted on or near the printhead 210) can be varied to selectively vary the electric field between the printhead 210 and the sheet metal material 114. For example, the charging device 1110 can create the electric field between the printhead 210 and the sheet metal material 114, or if the charging device 1210 is mounted on the printhead 210, it can charge the printhead 210 to create the electric field between the printhead 210 and the sheet metal material 114.

[0077] In another form, the control module 134 may control the application of an 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 particles for lubrication. For example, in one form, the charging device 1122 or 1222 may be further from the passages 430 (in Fig. 4) than the charging device 1110 or 1210. Instead, the external charging device 1122 or 1222 merely creates an external electric field in the gap between the print head 210 and the sheet metal material 114, through which the already charged particles traverse.

[0078] The control module 134 can selectively vary the external electric field to selectively vary the speed at which the charged lubricant particles fly toward the sheet metal material 114. Thus, the velocity of the lubricant particles can be controlled and varied without changing the waveform or voltage of the actuators 414 ( Fig. 4) needs to be changed, which would also change the size of the ejected particles. In one form, the control module 134 can adjust the electric field based on a speed of the sheet metal material 114 and / or a distance between the print head 210 and the sheet metal material 114. For example, a stronger electric field can be used for faster speeds of the sheet metal material 114 and / or for greater distances.

[0079] While the printhead 210 is shown ejecting the droplets perpendicular to the movement of the sheet metal material 114, other configurations may be used, such as at a non-perpendicular angle, for example.

[0080] With reference to Fig. 13 illustrates a schematic plan view of an alternative form of a lubrication system 130-6. The lubrication system 130-6 is similar to the other lubrication systems of the present disclosure unless otherwise shown or described herein. Accordingly, similar features are indicated by similar numbers, and only differences are explained in detail. In this example, the one or more plates 1114 ( Fig. 11) around a ring 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 one of the nozzles 310. In this example, the ring 1314 also surrounds a single one of the nozzles radially outward of the ring 1310, although other configurations may be used.

[0081] With reference to Fig. 14 illustrates a schematic top view of an alternative form of lubrication system 130-7. The lubrication system 130-7 is similar to the other lubrication systems of the present disclosure unless otherwise shown or described herein. Accordingly, similar features are indicated by similar numbers, and only differences will be explained in detail. In this example, the one or more charging plates 1114 is a ring 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 the nozzles 310. In this example, the ring 1414 also surrounds a plurality of the nozzles radially outward of the ring 1410, although other configurations may be used.

[0082] With reference to Fig. 15 illustrates a non-limiting example of a lubrication system 130-8 in which the printhead ejects droplets in a direction that is not perpendicular to the movement of the sheet metal material 114. In this example, the droplets are ejected in the same direction as the movement of the sheet metal material 114, although other configurations may be used. The lubrication system 130-8 is similar to the other lubrication systems of the present disclosure unless otherwise shown or described herein. Accordingly, similar features are indicated by similar numbers, and only differences are 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 deflected toward the sheet metal material 114. While the droplets are shown being charged by external plates 1114, the material may alternatively be charged in the manner described with reference to FIG. Fig. 12 can be charged in the manner shown and described.

[0083] With reference to Fig. 11-15, when the printheads 210 are positioned on both sides of the sheet metal material 114 (e.g., above and below), the droplets on one side of the sheet metal material 114 may be charged with an opposite polarity than the droplets on the opposite side. Thus, the electric field generated by the external charging device 1122 drives the droplets from both printheads 210 toward the sheet metal material 114.

[0084] Unless expressly stated otherwise herein, all numerical values ​​indicating mechanical / thermal properties, percentages of composition, dimensions and / or tolerances, or other characteristics are to be understood as modified by the word "about" or "approximately" when describing the scope of the present disclosure. This modification is desirable for various reasons, including industrial practice, material, manufacturing and assembly tolerances, and testability.

[0085] As used in this document, the phrase "at least one of A, B, and C" should be interpreted to mean a logical (A OR B OR C) using a non-exclusive logical OR, and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."

[0086] In this application, the term "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 combinational 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 (e.g.,integrator of an operational amplifier circuit as part of the heat flow data module) that provide the described functionality; or a combination of some or all of the foregoing, such as in a system-on-chip.

[0087] The term "memory" is a subset of the term "computer-readable medium." As used in this document, the term "computer-readable medium" does not include transitory electrical or electromagnetic signals propagating through a medium (such as a carrier wave); therefore, the term "computer-readable medium" can be considered tangible and non-transitory.Non-limiting examples of a non-transitory, tangible computer-readable medium include non-volatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (such as a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (such as an analog or digital magnetic tape or a hard disk drive), and optical storage media (such as a CD, a DVD, or a Blu-ray Disc).

[0088] The devices and methods described in this application may be implemented partially or entirely by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions embodied in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications that can be translated into computer programs through the routine work of a skilled technician or programmer.

[0089] The description of the disclosure is merely exemplary in nature, and thus variations that do not depart from the essence of the disclosure are intended to be within the scope of the disclosure. Such variations should not be considered a departure from the spirit and scope of the disclosure.

[0090] According to the present invention, a method for lubricating a sheet of material includes moving the sheet along a first direction; operating a pressure nozzle to deposit a lubricant onto the sheet as the sheet moves along the first direction, the pressure nozzle ejecting the lubricant in a second direction transverse to the first direction and toward a first side of the sheet; charging the lubricant with a first charging device such that the lubricant ejected from the pressure nozzle is in the form of charged droplets; operating a second charging device to apply an external electric field between the pressure nozzle and the sheet to attract the charged droplets to the sheet; and adjusting a velocity of the charged droplets by adjusting a strength of the external electric field.

[0091] In one aspect of the invention, the strength of the external electric field is controlled based on a speed of the sheet moving along the first direction.

[0092] In one aspect of the invention, the pressure nozzle is located under the sheet.

[0093] In one aspect of the invention, the sheet is a metal material. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 18 / 360,255

[0001]

Claims

[1] A method of lubricating a sheet of material, the method comprising: Moving the sheet along a first direction; Operating a pressure nozzle to deposit a lubricant on the sheet metal as the sheet metal moves along the first direction, the pressure nozzle ejecting the lubricant in a second direction transverse to the first direction and toward a first side of the sheet metal; 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. [2] The method of claim 1, further comprising adjusting a velocity of the charged droplets by adjusting the external electric field. [3] The method of claim 1, wherein a strength of the external electric field is controlled based on a speed of the sheet moving along the first direction. [4] The method of claim 1, wherein the lubricant is charged before being ejected from the printing nozzle. [5] The method according to claim 1, wherein the lubricant is charged while being ejected or immediately after being ejected from the printing nozzle. [6] The method of claim 1, wherein the pressure nozzle is located under the sheet. [7] The method of claim 1, wherein the external electric field is in the range of 30-120 kV / m. [8] The method of claim 1, wherein the charged droplets are charged with 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] A method according to any one of claims 1 to 9, wherein the charged droplets are charged to within the range of 10-200 kV. [11] A system for lubricating sheet metal to be formed into a metal component, the system comprising: a printhead including a plurality of nozzles, each nozzle of the plurality of nozzles including an orifice plate, an actuator, and a body, the orifice plate and the body cooperating to define a reservoir configured to hold lubricant, the actuator configured to vibrate the lubricant in the reservoir to eject the lubricant as droplets through an orifice of the orifice plate; a first charging device configured to electrically charge the lubricant; a second charging device configured to generate an external electric field between the print head and the metal sheet; and a control module configured to control operation of the second charging device to selectively adjust a strength of the external electric field. [12] The system of claim 11, wherein the control module is configured to selectively adjust the strength of the external electric field based on a speed of the sheet moving along a first direction. [13] The system of claim 11, wherein the first charging device is configured to electrically 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 electrically charge the lubricant while it is being ejected or immediately after it is ejected from each nozzle. [15] The system of claim 11, wherein the first charging device is configured to electrically charge the lubricant in the range of 10-200 kV, and the external electric field is in the range of 30-120 kV / m.

Images