Can body ironing system and method with reduced tear off

Abstract

Can body ironing systems are provided. Can body ironing systems include a ram assembly having a first position and a second position along an axis, the ram assembly including a ram and a punch. Can body ironing systems also include a tool pack having a plurality of ironing dies, each ironing die of the plurality of ironing dies including an inner surface defining a central aperture. Can body ironing systems include where the punch is received within the apertures of the plurality of ironing dies in the first position and is withdrawn from the apertures in the second position. Can body ironing systems include where at least one ironing die of the plurality of ironing dies includes a lubricant reservoir disposed adjacent to the central aperture.

Description

CAN BODY IRONING SYSTEM AND METHOD WITH REDUCED TEAR OFFREFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 63 / 613,100, filed on December 21, 2023, and entitled CAN BODY IRONING SYSTEM WITH REDUCED TEAR OFF, the content of which is hereby incorporated by reference in its entirety.FIELD OF THE INVENTION

[0002] This application relates to metalworking techniques, and more particularly to can body ironing and redraw processes.BACKGROUND

[0003] Cylindrical or tubular structures (hereinafter referred to as “cans”) are generally formed by making a blank out of material (such as metal) and then drawing the blank to form a shallow cup. After the shallow cup is initially drawn, a can body ironing system may carry the cups on an end of a reciprocating ram through a series of ironing dies to obtain a desired size and thickness of the can. The can body driven by the ram may contact a bottom forming tool to shape the bottom of the can (e.g., to have a dome). Systems generally lubricate the sheet material prior to drawing the shallow cup. However, during progressive reciprocation, the lubricant is exhausted, leading to high instances of tear off during ironing.SUMMARY

[0004] Embodiments covered by this patent are defined by the claims below, not this summary. This summary is a high-level overview of various embodiments and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this patent, any or all drawings, and each claim.

[0005] The present technology is generally directed to can body ironing systems. Systems include a ram assembly having a first position and a second position along an axis, the ram assembly including a ram and a punch. Systems also include a tool pack having a plurality of ironing dies, where each ironing die of the plurality of ironing dies has an inner surface defining a central aperture. Systems include where the punch is received within the apertures of the plurality of ironing dies in the first position, and is withdrawn from the apertures in the second position. Systems include where at least one ironing die of the plurality of ironing dies includes a lubricant reservoir disposed adjacent to the central aperture.

[0006] In embodiment, the plurality of ironing dies further include an entry surface and an exit surface, where the inner surface is formed between the entry surface and the exit surface. In yet more embodiments, the lubricant reservoir includes an injection port. Furthermore, in embodiments, the injection port includes an inlet fluidly connected to a lubricant source and an outlet formed in the exit surface. Moreover, in embodiments, the outlet is formed in the exit surface adjacent to the inner surface. Embodiments include where the lubricant reservoir includes a surface trap. Additionally or alternatively, the surface trap is formed in the inner surface adjacent to the exit surface.

[0007] The present technology is also generally directed to can body ironing systems. Systems include a ram assembly having a first position and a second position along an axis, the ram assembly including a ram and a punch. Systems also include a tool pack having three or more ironing dies, each ironing die of the three or more ironing dies including an inner surface defining a central aperture. Systems include where the punch is received within the apertures of the plurality of ironing dies in a first position, and is withdrawn from the apertures in a second position. Systems further include where at least two ironing dies of the three or more ironing dies include a lubricant reservoir disposed adjacent to the central aperture.

[0008] In embodiments, the tool pack further includes a redraw die at a proximal end of the central aperture, where a first ironing die of the three or more ironing dies is disposed adjacent to the redraw die and a third ironing die of the three or more ironing dies is disposed at a distal end of the central aperture. In more embodiments, a second ironing die of the three or more ironing dies is disposed between the first ironing die and the third ironing die, where the first ironing die and the second ironing die include the lubricant reservoir. In further embodiments, the lubricantreservoir of the first ironing die is disposed a first radial position, and lubricant reservoir of the second ironing die is disposed at a second radial position, where the first radial position is spaced apart from the second radial position. Additionally or alternatively, in embodiments, the redraw die further includes a lubricant reservoir. Furthermore, in embodiments, the plurality of dies further include an entry surface and an exit surface, where the inner surface is formed between the entry surface and the exit surface. In yet more embodiments, the lubricant reservoir includes an injection port, where the injection port includes an inlet fluidly connected to a lubricant source and an outlet formed in the exit surface. Moreover, in embodiments, the lubricant reservoir comprises a surface trap, and wherein the surface trap is formed in the inner surface adjacent to the exit surface.

[0009] The present technology is also generally directed to drawing and ironing method for forming a can. Methods include driving a metal article disposed around cup-shaped blank in a linear motion within a central aperture of a first ironing die of a tool pack. Methods include contacting an exterior surface of the metal article with a lubricant from a lubricant reservoir of the first ironing die. Methods include driving the metal article through a central aperture of a second ironing die.

[0010] In embodiments, methods include contacting the exterior surface of the metal article with a second lubricant from a second lubricant reservoir of the second ironing die and driving the metal article through a central aperture of a third ironing die. In further embodiments, the first ironing die, second ironing die, and / or third ironing die also include an entry surface, an exit surface, and an inner surface, wherein the inner surface defines the central aperture and is formed between the entry surface and the exit surface. Moreover, in embodiments, methods include where the contacting includes an injection port disposed in an exit surface of the first ironing die and / or second ironing die. In yet more embodiments, the contacting includes a surface trap disposed in an inner surface of the first ironing die and / or second ironing die.

[0011] Various implementations described herein can include additional systems, methods, features, and advantages, which cannot necessarily be expressly disclosed herein but will be apparent to one of ordinary skill in the art upon examination of the following detailed description and accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within the present disclosure and protected by the accompanying claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The specification makes reference to the following appended figures, in which use of like reference numerals in different figures is intended to illustrate like or analogous components.

[0013] FIG. 1 illustrates a can body iron system according to embodiments.

[0014] FIG. 2 illustrates a view of an ironing die according to embodiments of the present technology.

[0015] FIG. 3 illustrates a view of an ironing die according to embodiments of the present technology.

[0016] FIG. 4 illustrates a process of forming a can body according to embodiments of the present technology.DETAILED DESCRIPTION

[0017] The subject matter of embodiments of the present invention is described here with specificity to meet statutory requirements, but this description is not necessarily intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described. Directional references such as “up,” “down,” “top,” “bottom,” “left,” “right,” “front,” and “back,” among others, are intended to refer to the orientation as illustrated and described in the figure (or figures) to which the components and directions are referencing.

[0018] Ironing and redraw dies are utilized in making can bodies through a series of forming steps that progressively thin the sidewall of the can body while increasing the height of the can. The ironing process controls the final dimensions of the can sidewall, and produce the sidewall quality demanded in the industry, such as low roughness and high shine. However, the ironing process also contributes to failures, referred to as “tear offs” herein, where portions of the sidewall fracture from the can body. Such a failure is problematic, as tear offs require stoppage of can production, removal of the damage can, including tear offs, before the process may be restarted. Thus, it wouldbe beneficial to reduce the occurrence of tear offs, both to increase efficiency of the can body forming process, but also to improve the quality of the can body. Previous attempts have included incorporating a lubricant in a cooling fluid that is applied to the ironing system during processing. However, such systems failed to apply lubricant to an exterior surface of the can body between respective ironing operations, as coolant is freely flowed into the system, without ensuring can body contact. Thus, improvements to one or more of the discussed problems would be beneficial in the art.

[0019] Described herein are can body ironing systems and associated methods that reduce instances of tear off during can body ironing and / or redraw. Namely, the present technology has found that by providing one or more lubricant reservoirs at one or more of the ironing dies, tear off occurrence may be drastically reduced. Without wishing to be bound by theory, it is believed that the roughness of the can body decreases with successive ironing operations, resulting in less lubricant maintained in defects on the sheet material. Thus, lubricant in typical processes decreases as the can body thins and smooths, increasing the risk for tear off occurrence. In addition, ironing dies may remove lubricant during the ironing process (e.g. scraping lubricant from the surface), thus additionally or alternatively removing lubricant from the surface as the can is formed. The present technology has surprisingly found that by incorporating one or more lubricant reservoirs at a land area of an ironing die, targeted lubricant may be applied without disrupting the can body ironing process.

[0020] FIG. 1 illustrates an example of a can body ironing system 100 according to embodiments. In general, the can body ironing system 100 includes various components for performing a drawing and ironing process in which a can body 104 is formed from a cup-shaped blank 102. The cupshaped blank 102 may be formed from various materials as desired, and in some embodiments, the cup-shaped blank 102 is a metal such as but not limited to an aluminum or an aluminum alloy such as a Ixxx series aluminum alloy, a 2xxx series aluminum alloy, a 3xxx series aluminum alloy, a 4xxx series aluminum alloy, a 5xxx series aluminum alloy, a 6xxx series aluminum alloy, a 7xxx series aluminum alloy, a 8xxx series aluminum alloy and / or any other aluminum or aluminum alloy as desired.

[0021] As illustrated in FIG. 1, the can body ironing system 100 generally includes a ram assembly 106, a tool pack 108, and optionally a domer 110, among other components. A housingor enclosure 138 optionally is included for at least partially housing one or more components of the can body ironing system 100.

[0022] The ram assembly 106 includes a ram 112 and a punch 114 supported by the ram 112. The ram 112 is generally elongated along an axis 128, and the punch 114 may be supported at or proximate to an end of the ram 112. The punch 114 generally includes a punch sleeve 116 and a punch nose 118. In some embodiments, the punch sleeve 116 and the punch nose 118 are separate components, although in other embodiments the punch sleeve 116 and the punch nose 118 may be a single or monolithic component. The can body ironing system 100 includes an actuator 120 that drives or otherwise causes the ram assembly 106 to have reciprocating linear motion (represented by arrow 122) in a predetermined direction. Various types of actuators may be utilized as the actuator 120 causing the reciprocating linear motion of the ram assembly 106.

[0023] The tool pack 108 includes one or more dies 124, and in certain embodiments the tool pack 108 includes a plurality of dies 124, such as one or more dies, two or more dies, three or more dies, or more, or any ranges or values therebetween. Each die 124 includes an aperture 126 and is arranged along the axis 128 such that during drawing and ironing, the ram assembly 106 drives the cup-shaped blank 102 through the dies 124. Thus, in embodiments, the ram assembly may have a first position disposed fully or partially withing the central aperture formed by the plurality of dies, and a second withdrawn position, where the ram assembly is removed from the central aperture. In embodiments, each die of the plurality of dies may form a portion of the central aperture. For instance, in the illustrated embodiment, a redraw die 124A may form a first portion of a central aperture at a proximal end 142 of the tool pack 108, a first ironing die 124B may form a portion of a central aperture adjacent to the redraw die, a second ironing die 124C may form a portion of a central aperture adjacent to the first ironing die, and a third ironing die 124D may form a portion of a central aperture adjacent to a distal end 144 of the tool pack 108. However, it should be clear that the central aperture may have a length corresponding to the number of ironing dies utilized. Furthermore, it should be clear that the ram assembly may progressively drive from the proximal end 142 to the distal end 144 of the tool pack, through respective portions of the central aperture. As will be illustrated in greater detail in FIGS. 2 and 3, an inner surface of each die may define the central aperture.

[0024] In the example illustrated, the tool pack 108 includes four dies 124A-D - an initial die 124A may be a redraw die and the subsequent dies 124B-D, which may be ironing dies. As discussed in detail below, the redraw die may deform the cup-shaped blank 102 from a shallower and wider body into a narrower and longer body, and the ironing dies may iron sidewalls of the cup-shaped blank 102 from an initial thickness to an end thickness and to elongate the cup-shaped blank 102 to form the can body 104. The number of dies 124 illustrated should not be considered limiting.

[0025] In certain embodiments, the can body ironing system 100 includes a cup holder 127 in alignment with the axis 128 for initially receiving and supporting the cup-shaped blank 102 along the axis 128 before it is driven through the tool pack 108. The domer 110 of the can body ironing system 100 may shape a bottom of the can body 104 after the tool pack 108.

[0026] During a drawing and ironing process, the ram assembly 106 (particularly the punch 114) engages the cup-shaped blank 102 along the axis 128 and forces the cup-shaped blank 102 through the tool pack 108. As the cup-shaped blank 102 is forced through the tool pack 108, the cup-shaped blank 102 is drawn and ironed such that it deformed from a shallower and wider body into a narrower and longer can body 104 and with a reduced wall thickness. The domer 110 may shape the bottom of the can body 104. The ram assembly 106 may be driven at any suitable speed to produce a desired number of can bodies 104 per minute. As some non-limiting examples, the ram assembly 106 may be driven at speeds of approximately 200-450 strokes per minute, such as about 400-450 strokes per minute, where one stroke refers to one cycle of engaging a cup-shaped blank 102, forming, and releasing one can body 104. In other words, at 200-450 strokes per minute, the assembly engages, forms, and releases can bodies at a rate of about 200-450 strokes per minute.

[0027] During the drawing and ironing process, the cup-shaped blank 102 is subjected to various forces. A total force or load is the force applied by the punch 114 (through the ram assembly 106) onto the cup-shaped blank 102 during ironing. The total force or load generally represents the sum of a friction force between the punch 114 and sidewalls of the cup-shaped blank 102 and a punch nose force between the punch 114 and the bottom of the cup-shaped blank 102. In various embodiments, obtaining measurements of two of the three forces may allow for a determination of the third (e.g., obtaining measurements of the total force and the punch nose force may allow for determination of the friction force).

[0028] In various embodiments, the can body ironing system 100 includes a sensor system 130 with a first sensor 132 for measuring the total force or load and a second sensor 134 for measuring the punch nose force. The sensor system 130 optionally may include a controller 136 (e.g., processor and / or memory) communicatively coupled to the sensors 132, 134, and the controller 136 may determine friction forces during drawing and ironing based on the information from the sensors 132, 134. In other embodiments, the sensor system 130 need not include the controller 136, and the information from the sensors 132, 134 may be provided to an operator and / or other device as desired.

[0029] The controller 136 can include one or more of a general purpose processing unit, a processor specially designed for ironing analysis and / or ironing applications, a processor specially designed for wireless communications (such as a Programmable System On Chip from Cypress Semiconductor or other suitable processors). A memory may be provided with the controller 351 to store data gathered by various sensors of the sensor system 130, although it need not include a memory in other examples. The memory may include a long-term storage memory and / or a shortterm working memory. The memory may be used by the controller 136 to store a working set of processor instructions. The processor may write data to the memory. The memory may include a traditional disk device. In some aspects, the memory could include either a disk based storage device or one of several other type storage mediums to include a memory disk, USB drive, flash drive, remotely connected storage medium, virtual disk drive, or the like. Various other features including, but not limited to, a communication circuit / unit, an optional display, an optional speaker, and / or power storage unit may also be included in the controller 136 . In some aspects, some or all of the components of the controller 136 may be included together in a single package or sensor suite, such as within the same enclosure. In additional or alternative aspects, some of the components may be included together in an enclosure and the other components may be separate. Thus, the controller 136 may be a distributed system. This is merely one example and other configurations may be implemented, may be provided on the ram body 112, although in other examples, the controller 136 may be provided at other locations on the ram 112 and / or at other suitable locations that may or may not be on the ram 112. As such, the particular location of the controller 136 should not be considered limiting on the current disclosure.

[0030] In various aspects, the controller 136 communicates data with the sensors 132, 134 (and possibly other sensors) such that the controller 136 receives a data signal from the sensors 132, 134. In various examples, the data signals include forces, pressures, temperatures, accelerations, vibrations, etc. detected by the various sensors. The controller 136 can analyze the data from the sensors 132, 134 and control one or more parameters of the can body ironing system 100 (e.g., parameters that affect the ironing process). In other examples, the controller 136 can control the one or more parameters based on input received prior to the ironing process.

[0031] In certain embodiments, the second sensor 134 for measuring the punch nose force may be provided on the punch 114. In such embodiments, the second sensor 134 may be movable with the ram assembly 106 during the reciprocating linear motion of the drawing and ironing process.

[0032] Referring to FIG. 1, in various embodiments, the first sensor 132 for measuring the total load may be provided at a fixed location on or within the can body ironing system 100. In such embodiments, while the second sensor 134 is movable with the ram assembly 106, the first sensor 132 may generally maintain its position during the drawing and ironing process. Mounting the first sensor 132 at the fixed location within the can body ironing system 100 relative to the ram assembly 106, and particularly behind the last ironing die 124 of the can body ironing system 100, may allow for a measurement of the total load during the drawing and ironing process without requiring that the ram 112 be instrumented. Mounting the first sensor 132 at the fixed location may further reduce vibrational noise in sensor measurements thereby allowing for improved determinations of friction forces or other information based on the measured data. In various embodiments, the fixed first sensor 132 may reduce fatigue on the sensor (and extend the working life of the sensor) and may increase ease of access for installation, maintenance, and / or repair.

[0033] In certain embodiments, the first sensor 132 is provided with the tool pack 108, and in some embodiments, the first sensor 132 may be provided behind a last ironing die of the one or more dies 124 along the axis 128. In various embodiments, the first sensor 132 may be provided in place of a wear plate traditionally provided behind the ironing die 124. In the embodiment illustrated in FIG. 1, the first sensor 132 is mounted behind the third ironing die 124 of the tool pack 108. In certain embodiments, and as discussed in detail below, the first sensor 132 may be aligned with the dies 124 along the axis 128, which may minimize and / or eliminate the impact of the first sensor 132 on the precision alignment of the tool pack 108.

[0034] Regardless of whether one or more sensors are utilized, as discussed above, in conventional can body ironing systems, lubricant may be introduced to a sheet material utilized for forming can body 104 prior to an initial drawing and ironing operation. However, the lubricant may be removed when moving from die 124A towards die 124D due to the ironing process, increasing the risk of tear offs. In addition, without wishing to be bound by theory, it is believed that the decrease in surface roughness of the exterior of the can body due to the ironing process also removes surface defects from the exterior surface of the can body that can retain lubricant. Thus, as the can body decreases in thickness, surface roughness is decreased, and less lubricant may be retained on an exterior surface of the can body.

[0035] Referring to FIG. 2, a close-up view of an ironing die 224, which may be any one or more of ironing dies 124A - 124D discussed above and any one or more features of the ironing system of FIG. 1, is illustrated ironing a portion of a can body 204 disposed on punch sleeve 216. The ironing system 200 includes a punch sleeve 216 that drives the punch and can body 204 in an axial direction 220. As illustrated in FIG. 2, the ironing die 224 includes an entry surface 226, an inner surface 228, and an exit surface 234. The inner surface 228, also referred to as a “land area” defines an opening or gap 212, and also defines an interior diameter of the respective die (and therefore an interior diameter of the central aperture). During ironing, the punch drives the can body 204 through the gap 212 of the ironing die 224 in the axial direction 220 such that the sidewalls of the can body 204 are ironed from an initial thickness 230 to an end thickness 232. The ironing process may be repeated as many times as desired (and with as many types of ironing dies as desired) to produce a body having a desired wall thickness. However, as discussed above, in embodiments, three ironing dies alone or in combination with one redraw die may be utilized.

[0036] As discussed above, the present technology surprisingly shows that by incorporating one or more lubricant reservoirs within one or more of the ironing dies, lubricant may be precisely applied to the exterior surface of the sidewall of the can body. Thus, the lubricant may be applied (or re-applied) prior to the sidewall contacting a second ironing die (such as ironing die 124C discussed above). Namely, the present technology shows that by contacting the exterior surface of the can body with lubricant after one or more ironing operations, such as directly after in embodiments, lubricant may be precisely placed, exhibiting a marked improvement in tear offs and other defects.

[0037] As illustrated in FIG. 2, in embodiments, the reservoir may be or include an injection port 206. In the illustrated embodiment, one or more injection ports 206 may extend radially through the respective ironing die 224, having an inlet 236 connecting to a lubricant source, and an outlet 238 at an exit surface 234 of the ironing die, adjacent to the central aperture. While the injection port 206 is shown adjacent to land surface 228, in embodiments, the outlet may be disposed anywhere along exit surface 234. However, in embodiments, it may be desirable to contact the can body 204 after exiting the land surface 228, reapplying the lubricant in a controlled manner. While only one injection port 206 is illustrated, it should be clear that the respective ironing die 224 may have one or more, two or more, three or more, four or more injection ports, or any ranges or values there between, spaced radially around the ironing die 224.

[0038] Nonetheless, in embodiments, the lubricant may be flowed through or into the one or more reservoirs at a rate of about 1 gallon per minute to about 25 gallons per minute, such as about 2 gallons per minute to about 24 gallons per minute, such as about 3 gallons per minute to about 23 gallons per minute, such as about 4 gallons per minute to about 22 gallons per minute, such as about 5 gallons per minute to about 21 gallons per minute, such as about 6 gallons per minute to about 20 gallons per minute, such as about 7 gallons per minute to about 19 gallons per minute, such as about 8 gallons per minute to about 18 gallons per minute, such as about 9 gallons per minute to about 17 gallons per minute, such as about 9.5 gallons per minute to about 15.5 gallons per minute, or any ranges or values therebetween.

[0039] Furthermore, in embodiments, the one or more injection ports may have a diameter of about 0.01” to about 1”, such as from about 0.02” to about 0.8”, such as about 0.04” to about 0.6”, such as about 0.06” to about 0.4”, such as about 0.08” to about 0.2”, or any ranges or values therebetween.

[0040] In embodiments, some or all of the ironing dies, such as ironing dies 124A-124D may contain reservoirs, such as one or more injection ports 206, in embodiments. In embodiments, ironing die 124A may be a redraw die, and may not contain one or more injection ports, where ironing dies 124B-124D, or interior ironing dies 124B and / or 124C, may each contain one or more injections ports. However, in embodiments, some or all of ironing dies 124A-124D may contain one or more injection ports. In such embodiments, the one or more injection ports may be strategically staggered between adjacent ironing dies. Namely, a first ironing die, such as ironingdie 124B, may contain one or more injection ports formed radially around the inner surface of ironing die 124B, second ironing die, such as ironing die 124C may contain one or more injection ports formed radially around the inner surface of ironing die 124C, and / or third ironing die, such as ironing die 124D may contain one or more injection ports formed radially around the inner surface of ironing die 124D. In embodiments, an injection port, and outlet thereof, of the first ironing die may be disposed along a first radius, where a second injection port, and outlet thereof, of the second ironing die are disposed along a second radius, spaced apart from the first radius. In such a manner, the outlet may be disposed at or adjacent to the land surface without causing deficiencies in the ironing process, as any surface defects formed (if any) from the outlet, may be ironed at the second ironing die. Namely, as the outlet of the second ironing die is offset from the outlet of the first ironing die, if any defect is formed, it may be corrected by the subsequent ironing operation. The same may be true for the second ironing die to third ironing die. In embodiments, the third ironing die may have a third injection port, and outlet thereof, disposed along a third radius, spaced apart from both the first radius and the second radius. However, in embodiments, the third radius may be spaced apart from the second radius (of the adjacent ironing die), while being generally co-linear with the first radius. While only a single injection port and outlet have been discussed, it should be understood that when more than one injection port 206 is utilized on a respective ironing die 224, that all or a portion of the injection ports on a first ironing die may be disposed along one or more first radii and all of a portion of the injection ports on an adjacent ironing die may be disposed along one or more second radii, such that outlets of the first ironing die and adjacent ironing die are radially offset.

[0041] However, referring to FIG. 3, it should be understood that other reservoir orientations are contemplated herein for applying a lubricant to an exterior surface of a can body after one or more ironing operations. Referring to FIG. 3, a close-up view of an ironing die 324, which may be any one or more of ironing dies 124A - 124D and contain any one or more features of the ironing system of FIG. 1 discussed above, is illustrated ironing a portion of a can body 304 disposed on punch sleeve 316. The ironing system 300 includes a punch sleeve 316 that drives the punch and can body 304 in an axial direction 320. As illustrated in FIG. 3, the ironing die 324 includes an entry surface 326, an inner surface 328, and an exit surface 334. The inner surface 328, also referred to as a “land area” defines an opening or gap 312. During ironing, the punch drives the can body 304 through the gap 312 of the ironing die 324 in the axial direction 320 such that thesidewalls of the can body 304 are ironed from an initial thickness 330 to an end thickness 332. The ironing process may be repeated as many times as desired (and with as many types of ironing dies as desired) to produce a body having a desired wall thickness. However, as discussed above, in embodiments, three ironing dies alone or in combination with one redraw die may be utilized.

[0042] As illustrated in FIG. 3, in embodiments, the reservoir may be or include a surface trap 340, forming one or more depressions in a can body contacting surface of the respective die. In the illustrated embodiment, one or more surface traps 340 may extend circumferentially around the respective ironing die 224. While the surface trap 340 is shown as a depression formed as part of the land surface 328, in embodiments, the surface trap may be formed along exit surface 334. However, in embodiments, it may be desirable to contact the can body 304 as the can body is exiting the land surface 328, reapplying the lubricant in a controlled manner. While only one surface trap is illustrated, it should be clear that the respective ironing die 324 may have one or more, two or more, three or more, four or more surface traps, or more, or any ranges or values there between, spaced circumferentially around the ironing die 324. For instance, in embodiments, the surface trap 340 may not extend continuously around the circumference of the land surface and may instead be in the form of discrete holes or islands, spaced apart circumferentially and / or radially around and along land surface 328. In embodiments, the one or more surface traps may have a depth (e.g. from can body contact surface towards and exterior of the die) and / or a width (e g. extending along the body contact surface) of about 0.01” to about 0.5”, such as from about 0.025” to about 0.4”, such as from about 0.05” to about 0.3”, such as from about 0.1” to about 0.2, such as from about 0.125” to about 0.175”, or any ranges or values therebetween.

[0043] Regardless of the number and distribution of the surface trap(s) 340, in embodiments, the one or more depressions may have a generally smooth shoulder region 342. In embodiments, the shoulder 342, forming the interface between the surface trap 340 and land surface 328, may have a generally circular or sloped profile (e.g., may not form an angled surface), so as to prevent defects from forming and / or minimize any defects or depressions formed from the surface trap in a can surface.

[0044] In embodiments, the surface trap 340 may be filled with a lubricant prior to processing, such that lubricant is released from the surface trap during processing. In such a manner, the surface trap may be re-applied or re-filled with lubricant between can processing as needed.However, in embodiments, the surface trap 340 may be fluidly connected to a lubricant source, such as via one or more injection ports. In such a manner, the one or more surface traps 340 may be continuously refilled during processing.

[0045] In embodiments, some or all of the ironing dies, such as ironing dies 124A-124D may contain reservoirs, such as one or more surface traps 340, in embodiments. In embodiments, ironing die 124A may be a redraw die, and may not contain one or more surface traps, where ironing dies 124B-124D may each contain one or more surface traps. However, in embodiments, some or all of ironing dies 124A-124D may contain one or more surface traps. In such embodiments, the one or more surface traps may be strategically staggered between adjacent ironing dies. Namely, a first ironing die, such as ironing die 124B, may contain one or more surface traps formed at a first radial position along inner surface 328 of ironing die 124B, second ironing die, such as ironing die 124C may contain one or more surface traps formed at a second radial position along inner surface 328 of ironing die 124C, and / or third ironing die, such as ironing die 124D may contain one or more surface traps formed at a third radial position along inner surface 328 of ironing die 124D. In embodiments, a surface trap of the first ironing die may be disposed along the inner circumference of the ironing die (such as the land surface), at a first radial position, and a second surface trap of the second ironing die may be disposed at a section radial position along the inner circumference of the second ironing, spaced apart from the first radial position. In such a manner, the surface trap may be disposed at or adjacent to the land surface, as any surface defects formed (if any) from the surface trap, may be ironed at the second ironing die, as the surface trap of the second ironing die is offset from the surface trap of the first ironing die. The same may be true for the second ironing die to third ironing die.

[0046] In embodiments, the third ironing die may have a third surface trap disposed at a third radial position along the inner circumference of the third ironing die, spaced apart from both the first radial position and the second radial position. However, in embodiments, the third radial position may be spaced apart from the second radial position (of the adjacent ironing die), while being generally aligned with the first radial position. While only a single surface trap on each die has been discussed, it should be understood that when more than one surface trap 340 is utilized on a respective ironing die 324, that all or a portion of the surface traps on a first ironing die may be disposed at one or more first radial positions and all of a portion of the surface traps on anadjacent ironing die may be disposed at one or more second radial positions, such that surface traps of the first ironing die and adjacent ironing die are circumferentially offset.

[0047] FIG. 4 may illustrate one or more methods 400 of forming a can body according to embodiments of the present technology. Referring to FIG. 4, method 400 may include preparing a metal article, such as can body 104, 204, 304, for ironing and redraw. Preparing the metal article can include cutting it to the appropriate shape and dimensions, applying initial lubrication, etc. By way of example, but not limitation, a disk is blanked out of an aluminum sheet. The blank may be formed by any method known in the art, such as by punching or cutting. In one embodiment an outer cutting tool cuts an aluminum sheet into a disk, and the disk is immediately drawn into a cup. The disk may be drawn into a cup with an inner cup forming tool. The cutting and drawing may be carried out by a double action press, where the first action performs disk cutting and the second action performs cup forming in a continuous motion.

[0048] In various aspects, the formed cup has a fairly large diameter that requires further operation to reduce its size to a smaller diameter to facilitate subsequent operations. This is accomplished by a redraw process. A suitable redraw process may include, for example, the direct redraw process wherein the cup is drawn from inside of the cup base by using similar cup forming tools to reduce its diameter and displace the material to form a taller cup wall. Another suitable redraw process for use in the methods described herein is the reverse redraw process wherein the cup is drawn from the bottom of the cup and metal is folded in an opposite direction to form the taller cup wall. The methods disclosed herein may include either of these redraw processes, but are not limited to these redraw processes. Depending on machine requirements, limitations, and process requirements, there may be multiple redraw processes or combinations of redraw processes. After the cup is drawn to a final diameter, as described in detail below, an ironing tool will stretch and thin the cup wall to achieve the final wall thickness and length. Preparing the metal article can also include positioning the metal article relative to the punch and / or the ironing die for ironing.

[0049] Operation 405 may include engaging the metal article with punch 114, driving the article in the axial direction through one or more ironing dies, such ironing dies 124A-124D discussed in regards to FIGS. 1-3. As the metal article is drive through the ironing die(s), a wall thickness of the metal article is reduced. Nonetheless, in embodiments, operation 405 may include driving thearticle in an axial direction through the first ironing die, such as first ironing die 124B discussed above, and may include driving the article through a redraw die and the first ironing die.

[0050] At operation 410, lubrication may be applied at the first ironing die, but downstream of the first ironing operation (e g., where the can body is thinned at entry surface / land surface interface), utilizing one or more reservoirs discussed above. Namely, by applying lubricant to an exterior surface (e.g., sidewall of the can body), after a first ironing operation, such as after a first thinning of the can body sidewall, lubricant may be re-applied and maintained on the exterior surface prior to a second ironing operation. Conversely, application prior to or during an ironing operation results in scraped or lost lubricant, forming an insufficient lubricated surface for further ironing operations. Thus, the metal article may be driven through a second ironing die at operation 415, with greatly reduced or even eliminated risk of tear offs and surface defects.

[0051] As illustrated, methods according to the present technology may include repeating the driving and lubricating operation for the number of ironing die operations desired. In the illustrated embodiment, three ironing dies may be utilized. Thus, optional operation 420 may therefore include applying lubricant at the second ironing die, but downstream of the second ironing operation, utilizing one or more reservoirs discussed above. Namely, by applying lubricant to an exterior surface (e g., sidewall of the can body), after a second ironing operation, such as after a second thinning of the can body sidewall, lubricant may be re-applied and maintained on the exterior surface prior to a third ironing operation. For instance, optional operation 425 may include driving the metal article through a third ironing die, such as third ironing die 124D discussed above. If additional ironing operations are desired, it should be clear that the drive and application operations may be repeated based upon the number of ironing dies and respective operations. Furthermore, in embodiments, it may be desired to apply lubricant at a redraw die, prior to a first ironing operation. Nonetheless, in embodiments, the initial lubricant applicant may be sufficient for a redraw ironing operation and a first ironing operation.

[0052] A collection of exemplary embodiments is provided below, including at least some explicitly enumerated as an “Illustration” providing additional description of a variety of example embodiments in accordance with the concepts described herein. These illustrations are not meant to be mutually exclusive, exhaustive, or restrictive; and the disclosure not limited to these exampleillustrations but rather encompasses all possible modifications and variations within the scope of the issued claims and their equivalents.

[0053] As used below, any reference to a series of aspects (e.g., “Aspects 1-4”) or nonenumerated group of aspects (e.g., “any previous or subsequent aspect”) is to be understood as a reference to each of those aspects disjunctively (e.g., “Aspects 1-4” is to be understood as “Aspects 1, 2, 3, or 4”).

[0054] Aspect 1 : A can body ironing system comprising: a ram assembly having a first position and a second position along an axis, the ram assembly comprising a ram and a punch; and a tool pack comprising: a plurality of ironing dies, each ironing die of the plurality of ironing dies comprising an inner surface defining a central aperture, wherein the punch is received within the apertures of the plurality of ironing dies in the first position, and is withdrawn from the apertures in the second position; and wherein at least one ironing die of the plurality of ironing dies comprise a lubricant reservoir disposed adjacent to the central aperture.

[0055] Aspect 2: The system of aspect 1, wherein the plurality of ironing dies further comprise an entry surface and an exit surface, wherein the inner surface is formed between the entry surface and the exit surface.

[0056] Aspect 3: The system of aspect 1 or 2, wherein the lubricant reservoir comprises an injection port.

[0057] Aspect 4: The system of any one of aspects 1 to 3, wherein the injection port comprises an inlet fluidly connected to a lubricant source and an outlet formed in the exit surface.

[0058] Aspect 5: The system of any one of aspects 1 to 4, wherein the outlet is formed in the exit surface adjacent to the inner surface.

[0059] Aspect 6: The system of any one of aspects 1 to 5, wherein the lubricant reservoir comprises a surface trap.

[0060] Aspect 7: The system of any one of aspects 1 to 6, wherein the surface trap is formed in the inner surface adjacent to the exit surface.

[0061] Aspect 8: A can body ironing system comprising: a ram assembly having a first position and a second position along an axis, the ram assembly comprising a ram and a punch; and a toolpack comprising three or more ironing dies, each ironing die of the three or more ironing dies comprising an inner surface defining a central aperture, wherein the punch is received within the apertures of the plurality of ironing dies in a first position, and is withdrawn from the apertures in a second position; and wherein at least two ironing dies of the three or more ironing dies comprise a lubricant reservoir disposed adjacent to the central aperture.

[0062] Aspect 9: The system of any one of aspects 1 to 8, wherein the tool pack further comprises a redraw die at a proximal end of the central aperture and wherein a first ironing die of the three or more ironing dies is disposed adjacent to the redraw die and a third ironing die of the three or more ironing dies is disposed at a distal end of the central aperture.

[0063] Aspect 10, The system of any one of aspects 1 to 9, wherein a second ironing die of the three or more ironing dies is disposed between the first ironing die and the third ironing die, wherein the first ironing die and the second ironing die comprise the lubricant reservoir.

[0064] Aspect 11: The system of any one of aspects 1 to 10, wherein the lubricant reservoir of the first ironing die is disposed a first radial position, and lubricant reservoir of the second ironing die is disposed at a second radial position, wherein the first radial position is spaced apart from the second radial position.

[0065] Aspect 12: The system of any one of aspects 1 to 11, wherein the redraw die further comprises a lubricant reservoir.

[0066] Aspect 13: The system of any one of aspects 1 to 12, wherein the plurality of dies further comprise an entry surface and an exit surface, wherein the inner surface is formed between the entry surface and the exit surface.

[0067] Aspect 14: The system of any one of aspects 1 to 13, wherein the lubricant reservoir comprises an injection port, and wherein the injection port comprises an inlet fluidly connected to a lubricant source and an outlet formed in the exit surface.

[0068] Aspect 15: The system of any one of aspects 1 to 14, wherein the lubricant reservoir comprises a surface trap, and wherein the surface trap is formed in the inner surface adjacent to the exit surface.

[0069] Aspect 16: A drawing and ironing method for forming a can, the method comprising: driving a metal article disposed around cup-shaped blank in a linear motion within a centralaperture of a first ironing die of a tool pack; contacting an exterior surface of the metal article with a lubricant from a lubricant reservoir of the first ironing die; and driving the metal article through a central aperture of a second ironing die.

[0070] Aspect 17: The method of aspect 16, further comprising contacting the exterior surface of the metal article with a second lubricant from a second lubricant reservoir of the second ironing die and driving the metal article through a central aperture of a third ironing die.

[0071] Aspect 18: The method of aspect 16 or 17 wherein the first ironing die, second ironing die, and / or third ironing die further comprise an entry surface, an exit surface, and an inner surface, wherein the inner surface defines the central aperture and is formed between the entry surface and the exit surface.

[0072] Aspect 19: The method of any one of aspects 16 to 18, wherein the contacting comprises an injection port disposed in an exit surface of the first ironing die and / or second ironing die.

[0073] Aspect 20: The method of any one of aspects 16 to 19, wherein the contacting comprises a surface trap disposed in an inner surface of the first ironing die and / or second ironing die.

[0074] As used herein, the terms “invention,” “the invention,” “this invention,” and “the present invention” are intended to refer broadly to all of the subject matter of this patent application and the claims below. Statements containing these terms should be understood not to limit the subject matter described herein or to limit the meaning or scope of the patent claims below.

[0075] In this description, reference is made to alloys identified by AA numbers and other related designations, such as “series” or “5xxx.” For an understanding of the number designation system most commonly used in naming and identifying aluminum and its alloys, see “International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys” or “Registration Record of Aluminum Association Alloy Designations and Chemical Compositions Limits for Aluminum Alloys in the Form of Castings and Ingot,” both published by The Aluminum Association.

[0076] As used herein, the meaning of “a,” “an,” and “the” includes singular and plural references unless the context clearly dictates otherwise.

[0077] The subject matter of embodiments of the present disclosure is described here with specificity to meet statutory requirements, but this description is not necessarily intended to limitthe scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described. Directional references such as “up,” “down,” “top,” “bottom,” “left,” “right,” “vertical,” “horizontal,” “lateral,” “longitudinal,” “front,” and “back,” among others, are intended to refer to the orientation as illustrated and described in the figure (or figures) to which the components and directions are referencing.

[0078] The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate embodiments of the invention, and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0079] The above-described aspects are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the present disclosure. Many variations and modifications can be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the present disclosure. All such modifications and variations are intended to be included herein within the scope of the present disclosure, and all possible claims to individual aspects or combinations of elements or steps are intended to be supported by the present disclosure. Moreover, although specific terms are employed herein, as well as in the claims that follow, they are used only in a generic and descriptive sense, and not for the purposes of limiting the described embodiments, nor the claims that follow.

Claims

CLAIMSThat which is claimed:

1. A can body ironing system comprising: a ram assembly having a first position and a second position along an axis, the ram assembly comprising a ram and a punch; and a tool pack comprising: a plurality of ironing dies, each ironing die of the plurality of ironing dies comprising an inner surface defining a central aperture, wherein the punch is received within the apertures of the plurality of ironing dies in the first position, and is withdrawn from the apertures in the second position; and wherein at least one ironing die of the plurality of ironing dies comprise a lubricant reservoir disposed adjacent to the central aperture.

2. The can body ironing system of claim 1, wherein the plurality of ironing dies further comprise an entry surface and an exit surface, wherein the inner surface is formed between the entry surface and the exit surface.

3. The can body ironing system of claim 2, wherein the lubricant reservoir comprises an injection port.

4. The can body ironing system of claim 3, wherein the injection port comprises an inlet fluidly connected to a lubricant source and an outlet formed in the exit surface.

5. The can body ironing system of claim 4, wherein the outlet is formed in the exit surface adjacent to the inner surface.

6. The can body ironing system of claim 2, wherein the lubricant reservoir comprises a surface trap.

7. The can body ironing system of claim 6, wherein the surface trap is formed in the inner surface adjacent to the exit surface.

8. A can body ironing system comprising: a ram assembly having a first position and a second position along an axis, the ram assembly comprising a ram and a punch; and a tool pack comprising three or more ironing dies, each ironing die of the three or more ironing dies comprising an inner surface defining a central aperture, wherein the punch is received within the apertures of the plurality of ironing dies in a first position, and is withdrawn from the apertures in a second position; and wherein at least two ironing dies of the three or more ironing dies comprise a lubricant reservoir disposed adjacent to the central aperture.

9. The can body ironing system of claim 8, wherein the tool pack further comprises a redraw die at a proximal end of the central aperture and wherein a first ironing die of the three or more ironing dies is disposed adjacent to the redraw die and a third ironing die of the three or more ironing dies is disposed at a distal end of the central aperture.

10. The can body ironing system of claim 9, wherein a second ironing die of the three or more ironing dies is disposed between the first ironing die and the third ironing die, wherein the first ironing die and the second ironing die comprise the lubricant reservoir.

11. The can body ironing system of claim 10, wherein the lubricant reservoir of the first ironing die is disposed a first radial position, and lubricant reservoir of the second ironing die is disposed at a second radial position, wherein the first radial position is spaced apart from the second radial position.

12. The can body ironing system of claim 10, wherein the redraw die further comprises a lubricant reservoir.

13. The can body ironing system of claim 8, wherein the plurality of dies further comprise an entry surface and an exit surface, wherein the inner surface is formed between the entry surface and the exit surface.

14. The can body ironing system of claim 13, wherein the lubricant reservoir comprises an injection port, and wherein the injection port comprises an inlet fluidly connected to a lubricant source and an outlet formed in the exit surface.

15. The can body ironing system of claim 13, wherein the lubricant reservoir comprises a surface trap, and wherein the surface trap is formed in the inner surface adjacent to the exit surface.

16. A drawing and ironing method for forming a can, the method comprising: driving a metal article disposed around cup-shaped blank in a linear motion within a central aperture of a first ironing die of a tool pack; contacting an exterior surface of the metal article with a lubricant from a lubricant reservoir of the first ironing die; and driving the metal article through a central aperture of a second ironing die.

17. The method of claim 16, further comprising contacting the exterior surface of the metal article with a second lubricant from a second lubricant reservoir of the second ironing die and driving the metal article through a central aperture of a third ironing die.

18. The method of claim 17, wherein the first ironing die, second ironing die, and / or third ironing die further comprise an entry surface, an exit surface, and an inner surface, wherein the inner surface defines the central aperture and is formed between the entry surface and the exit surface.

19. The method of claim 18, wherein the contacting comprises an injection port disposed in an exit surface of the first ironing die and / or second ironing die.

20. The method of claim 18, wherein the contacting comprises a surface trap disposed in an inner surface of the first ironing die and / or second ironing die.

Images