Through flash guide for high-speed drilling of electric discharge processing system

Abstract

To provide a through flash guide for high-speed drilling of an electric discharge processing system.SOLUTION: A through flash guide (100) includes a quill (104) extending from a mast (12) attached to an electric discharge processing device (10) toward a work table. An electrode (18) of the electric discharge processing device penetrates the quill and extends up to the work table. The quill includes a dielectric fluid passage in the periphery of the electrode (18). A guide distal end (150) on the quill receives dielectric fluid and guides the dielectric fluid to a focal point (F) distant from a distal end of the guide distal end by a stand-off distance (S).SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates generally to electrical discharge machining ("EDM") systems, particularly to fast hole drilling ("FHD") with such systems, and more particularly to a through flush guide for improving FHD performance. [Background technology]

[0002] During FHD, an EDM electrode is used to remove (erode) material from a metal workpiece in a tight circular area to form a hole in the workpiece. The electrode is fed through a guide that includes a horizontal guide body that holds a vertical hollow quill positioned above the workpiece. The tip of the quill is away from the workpiece, and the tip of the electrode protrudes toward the machining location on the workpiece. A spark or plasma channel between the tip of the electrode and the workpiece converts at least a portion of the workpiece metal into plasma, removing (eroding) material from the workpiece. As material is removed (eroded), the electrode is fed into the resulting cavity, forming a substantially cylindrical hole in the workpiece. As workpiece material is removed (eroded) and the electrode material is consumed, metal debris can accumulate in the hole and impede hole formation. For example, the presence of debris can result in arcing between the electrode and the workpiece through the debris.

[0003] To reduce debris collection, EDM systems can include a flush arrangement that delivers a liquid to the hole, flooding the hole and carrying the collected material away from the work site. Typically, a dielectric liquid, such as water or a dielectric oil, is used as the flushing liquid, broadly referred to herein as a “dielectric fluid.” It should be understood that the term “dielectric fluid” is not limited to the above examples and can include any suitable dielectric fluid now known or later discovered to be suitable. Some flushing arrangements employ so-called “jet flushing” (also known as “side flushing”), in which a nozzle or orifice directs the dielectric fluid toward the work site. However, this is less precise in FHD than, for example, pressure flushing, also known as injection flushing. Pressure flushing is a common flushing technique in which a dielectric fluid is delivered to the work site under pressure. There are two types of pressure flushing: through the workpiece and through the electrode ("through flushing"). In through flushing, the dielectric fluid is pumped through the electrode, exits the tip of the electrode at the machining site, overflows at the machining location, and flows out of the machining location. The dielectric fluid carries debris away from the machining location and can also cool the electrode and workpiece at the machining location.

[0004] A factor in the benefit of flushing is the design of the electrode used. In through-flushing, the electrode is hollow and has an outer diameter, which determines the diameter of the hole it drills. Electrodes can have a single passage through which the dielectric fluid passes, or multiple passages. No matter how many passages an electrode has, the ratio of inner diameter to outer diameter determines the electrode's durability and achievable drilling speed. Generally, drill speed varies directly with the value of this ratio, while wall thickness, electrode durability, and degree of tapering vary inversely with the value of the ratio. That is, thin-walled electrodes with less tapering can drill faster, but they wear out faster than thick-walled electrodes.

[0005] In FHD, single-passage electrodes are favored for their superior performance over other designs. However, prior art systems for through-flushing with single-passage electrodes can result in more debris remaining in the hole than desired, particularly as the electrode approaches the far surface of the workpiece during the pre-breakthrough period. This reduces cutting efficiency and causes machining to proceed slowly until the electrode finally breaks through the far surface of the workpiece. To try to combat this problem, hybrid flushing arrangements have been used to varying degrees of success. For example, combining through-flushing and jet flushing can improve results. However, even hybrid systems can sometimes experience reduced machining progress during the near-breakthrough period. Summary of the Invention

[0006] All aspects, examples and features described below may be combined in any manner technically possible.

[0007] One aspect of the present disclosure provides a through flush guide for fast hole drilling (“FHD”) electrical discharge machining (“EDM”). The through flush guide includes a guide body. The guide body is particularly configured for attachment to an EDM apparatus. The guide body, in particular, comprises a mounting end configured for attachment to an EDM apparatus. The flush guide further includes a quill with a hollow body having a first end and a second end opposite the first end. The first end is mounted on the guide body and configured to receive and convey an electrode of the EDM apparatus. The quill is configured to receive and convey dielectric fluid around the electrode from the first end of the quill to the second end of the quill.The flash guide further includes a guide tip on the second end of the quill. The quill and the guide tip have a common centerline. The guide tip includes an electrode passage defined along the centerline and a dielectric fluid passage defined around the electrode passage. A funnel portion of the guide tip is configured to direct dielectric fluid toward a focal point located at a standoff distance away from an end of the guide tip.

[0008] Another aspect of the present disclosure includes any of the preceding aspects, wherein the guide tip has a main portion with an inner wall and an inner body, the electrode passage is defined along a center of the inner body, and the dielectric fluid passage is defined between an outer wall of the inner body and the inner wall of the main portion.

[0009] Another aspect of the present disclosure includes any of the preceding aspects, wherein the funnel portion is part of the main portion that begins a shift distance away from the end of the guide tip through which the electrode and the dielectric fluid exit, and an inclination of the inner wall of the main portion changes to a first angle relative to the centerline of the guide tip at the shift distance.

[0010] Another aspect of the present disclosure includes any of the preceding aspects, wherein the dielectric fluid passage is frustoconical in the funnel portion.

[0011] Another aspect of the present disclosure includes any of the preceding aspects, wherein an inclination of the outer wall of the inner body changes to a second angle relative to the centerline of the guide tip at the shift distance.

[0012] Another aspect of the present disclosure includes any of the preceding aspects, wherein the second angle and the first angle are equal.

[0013] Another aspect of the present disclosure includes any of the preceding aspects, wherein the electrode passage of the guide tip is larger at an entry thereof than at the end of the guide tip.

[0014] Another aspect of the present disclosure includes any of the preceding aspects, further including an electrode guide tube within and concentric with the quill, the electrode guide tube being configured to receive the electrode.

[0015] Another aspect of the present disclosure includes any of the preceding aspects, wherein the end of the guide tip is configured to remain the standoff distance away from a workpiece during the FHD EDM process.

[0016] One aspect of the present disclosure provides a through flush guide for an FHD using an EDM apparatus. The through-flash guide includes a guide body with a mounting end configured for attachment to an EDM apparatus and a distal end opposite the mounting end; a quill with a hollow body having a first end mounted on the guide body and a second end opposite the first end; a guide tip on the second end of the quill, wherein the quill and the guide tip have a common centerline; and an electrode passage defined in and extending through the guide body along the centerline to exit at an end of the guide tip, the electrode passage configured to receive an electrode of the EDM apparatus.the electrode passage configured to receive an electrode of the EDM apparatus; and a dielectric fluid passage defined in and extending through the guide body, the quill, and the guide tip to the end of the guide tip, wherein the dielectric fluid passage surrounds the electrode passage in the quill and the guide tip, and a funnel portion of the guide tip defines the dielectric fluid passage to deliver dielectric fluid to a focal point located at a standoff distance from the end of the guide tip.

[0017] Another aspect of the present disclosure includes any of the preceding aspects, wherein the guide tip includes an inner wall and an inner body, and the inner wall of the guide tip together with the outer wall of the inner body define the dielectric fluid passage in the guide tip.

[0018] Another aspect of the present disclosure includes any of the preceding aspects, wherein the inner wall in the funnel portion is inclined at a first angle toward the centerline of the guide tip.

[0019] Another aspect of the present disclosure includes any of the preceding aspects, wherein a plurality of supports extend between the inner wall of the guide tip and the inner body.

[0020] Another aspect of the present disclosure includes any of the preceding aspects, wherein the dielectric fluid passage in the guide body includes a connection configured to deliver dielectric fluid to an interior of the electrode.

[0021] One aspect of the present disclosure provides an electrical discharge machining (EDM) apparatus. The EDM apparatus includes a work platform, a mast extending above the work platform, an electrode feed system, a dielectric fluid supply, and a guide for an electrode of the EDM apparatus. The guide includes a guide body mounted on the mast of the EDM apparatus, a quill with a hollow body having a first end mounted on the guide body and a second end opposite the first end, and a guide tip on the second end of the quill. The quill and the guide tip have a common centerline, and the guide body is configured to deliver an electrode from the electrode feed system to the quill and to deliver dielectric fluid from the fluid supply to the quill.a first end of the quill configured to receive and convey the electrode along the centerline to the guide tip, the quill configured to receive and convey the dielectric fluid around the electrode from the first end of the quill to the guide tip, the guide tip configured to receive the electrode from the quill and including an electrode passage defined along the centerline configured to receive the electrode from the quill, the guide tip also includes a dielectric fluid passage defined around the electrode passage, and a funnel portion of the guide tip configured to direct the dielectric fluid toward a focal point located a standoff distance from the end of the guide tip. dielectric fluid toward a focal point located at a standoff distance away from an end of the guide tip).

[0022] Another aspect of the present disclosure includes any of the preceding aspects, wherein the guide tip has a main portion with an inner wall around an inner body, the electrode passage is defined along a center of the inner body, and the dielectric fluid passage is defined between an outer wall of the inner body and the inner wall of the main portion.

[0023] Another aspect of the present disclosure includes any of the preceding aspects, wherein the funnel portion is part of the main portion that begins a shift distance away from the end of the guide tip through which the electrode and the dielectric fluid exit, and an inclination of the inner wall of the main portion changes to a first angle relative to the centerline of the guide tip at the shift distance.

[0024] Another aspect of the present disclosure includes any of the preceding aspects, wherein an inclination of the outer wall of the inner body changes to a second angle relative to the centerline of the guide tip at the shift distance.

[0025] Another aspect of the present disclosure includes any of the preceding aspects, wherein the second angle and the first angle are equal.

[0026] Another aspect of the present disclosure includes any of the preceding aspects, wherein the guide tip electrode passage is larger at its entrance than at the end of the guide tip.

[0027] Two or more aspects described in this disclosure, including those described in this Summary, may be combined to form an embodiment not specifically described herein.

[0028] The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. [Brief explanation of the drawings]

[0029] These and other features of the present disclosure will be more readily understood from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings illustrating various embodiments of the present disclosure. [Figure 1] FIG. 1 is a schematic side view of an EDM apparatus using a through-flash guide according to an embodiment of the present disclosure. [Figure 2] 1 is a schematic cross-sectional view of a through flash guide according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a schematic exploded perspective view of the through flash guide according to the embodiment of the present disclosure seen in FIG. 2; [Figure 4] FIG. 10 is an enlarged schematic cross-sectional view of a guide tip of a through-flush guide according to an embodiment of the present disclosure. [Figure 5] 5 is a further enlarged schematic cross-sectional view of the guide tip of FIG. 4 in accordance with an embodiment of the present disclosure. [Figure 6A] 1 is a schematic graph of the performance of an EDM device using a prior art flash arrangement. [Figure 6B] 1 is a schematic graph of the performance of an EDM device using a prior art flash arrangement. [Figure 6C] 10 is a schematic graph of the performance of an EDM device using a through-flash guide according to an embodiment of the present disclosure.

[0030] It should be noted that the drawings of the present disclosure are not necessarily to scale. The drawings are intended to depict only typical aspects of the present disclosure and therefore should not be considered as limiting the scope of the present disclosure. In the drawings, like numbers represent like elements between the drawings. DETAILED DESCRIPTION OF THE INVENTION

[0031] As an initial matter, a clear explanation of the state of the art requires the selection of specific terminology when referring to and describing relevant machine components within the exemplary application of a through-flush guide for high-speed drilling ("FHD") using electrical discharge machining ("EDM"). In doing so, common industry terminology will be used, where possible, and employed in a manner consistent with its common meaning. Unless otherwise specified, such terms should be given a broad interpretation consistent with the context of this application and the appended claims. Those skilled in the art will recognize that particular components are often referred to using several different or overlapping terms. Something described herein as a single part may include and be referred to as being made up of multiple parts in other contexts. Alternatively, something described herein as including multiple components may be referred to elsewhere as a single part.

[0032] Additionally, several descriptive terms may be used periodically herein, and it may be helpful to define these terms at the beginning of this section. These terms and their definitions are as follows, unless otherwise specified: "Downstream" and "upstream," as used herein, are terms that refer to a direction relative to the flow of a fluid, such as a dielectric fluid, through an electrical discharge machining apparatus or through one of an electrical discharge machining apparatus component systems. The term "downstream" corresponds to the direction of fluid flow, and the term "upstream" refers to the direction opposite the flow (i.e., the direction in which the flow occurs).

[0033] Furthermore, certain descriptive terms may be regularly used herein, as explained below: The terms "first," "second," and "third" may be used interchangeably to distinguish one component from another, and are not intended to imply the position or importance of the individual components.

[0034] The terms used herein are for the purpose of describing particular embodiments only and are not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. It will be further understood that as used herein, the terms "comprises" and / or "comprising" specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. "Optionally" or "optional" means that the subsequently described event or circumstance may or may not occur, or the subsequently described component or element may or may not be present, and that the description includes instances in which the event occurs or the element is present as well as instances in which the event does not occur or the element is not present.

[0035] When an element or layer is referred to as being "on," "engaged," "connected," "coupled," or "attached" to another element or layer, it may be directly engaged, connected, coupled, or attached to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is "directly" on, "directly engaged," "directly connected," or "directly coupled" to another element or layer, there are no intervening elements or layers present. Other words used to describe relationships between elements should be interpreted similarly (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). As used herein, the term "and / or" includes any combination of one or more of the associated listed items. The verb forms of "couple" and "mount" may be used interchangeably herein.

[0036] As indicated above and with reference to accompanying FIGS. 1-6C, the present disclosure provides a through-flush guide for FHD EDM. As seen schematically in FIG. 1, the EDM apparatus 10 may include a mast 12 extending above a work platform 14. The mast 12 may support a through-flush guide 100 configured to mount thereto. The mast 12 may also include an electrode supply system (or supply arrangement) 16 that supplies an electrode 18 used to discharge machine a workpiece 20 at a work site 22 thereon. As known in the art, the electrode 18 may be a solid wire or may be hollow with one or more flow passages extending along its length. For FHD, the electrode 18 preferably has a single flow passage extending therethrough, although any suitable electrode configuration may be employed in embodiments as disclosed herein. As also shown schematically in FIG. 1, a dielectric fluid supply 24 may be included and may be connected to the flash guide 100 via a conduit 26 or the like. For example, the conduit 26 may connect to a dielectric fluid passage 106 defined in the guide body 102 of the through-flush guide 100, which passage 106 may then direct the dielectric fluid to the machining location 22 via a quill 104 attached to the guide body 102. The guide body 102 may be configured to attach to the mast 12 or other portion of the EDM machine apparatus 10 in any suitable manner known now or in the future.

[0037] As seen in more detail in the cross-sectional view of FIG. 2 and the exploded view of FIG. 3 , the quill 104 includes a hollow body 105 having a first (entrance) end attached to the guide body 102 and a second (exit) end opposite the first end. The quill 104 may be configured to receive and transport the electrode 18 of the electrical discharge machining apparatus 10 along a centerline CL of the quill 104. The guide body 102 may include an electrode receiver 110 at an upper portion thereof, which may be a conical or frustoconical cavity formed in the head of a bolt 112 or the like. The electrode receiver 110 may have an entrance defined therein that is wider than the outer diameter of the electrode 18. The electrode receiver 110 may also include an electrode passage defined therein that is slightly larger than the outer diameter of the electrode 18.

[0038] The spacer tube 114 may be axially interposed between the bolt 112 and the quill 104 and may be coupled to the first end of the quill 104 by corresponding threads or the like 115 formed on the inner surface of the spacer tube 114 and the outer surface of the first end of the quill 104. The spacer tube 114 may also be coupled to the guide body 102 by a friction fit or by threads or the like (not shown) formed on the outer surface of the spacer tube 114 and the inner surface of the electrode passage. The spacer tube 114 may include a junction 116 ( FIG. 2 ) for the dielectric fluid passage 106 and the electrode passage. In embodiments, the junction 116 may direct fluid from the dielectric fluid passage 106 to the quill 104. In other embodiments, the junction 116 may also direct the dielectric fluid to and / or along the electrode 18. It should be understood that features of the electrode receiver 110 and / or the spacer tube 114 may be integrally formed with the guide body 102 in embodiments.

[0039] In an embodiment, the quill 104 may include an electrode guide tube 118 concentric therewith and through which the electrode 18 may extend. Regardless of whether the quill 104 includes the electrode guide tube 118, an upper flow passage 120 may be defined between the inner surface of the quill 104 and the electrode 18. That is, the quill 104 may be configured to receive and transport a dielectric fluid around the electrode 18 within the upper flow passage 120 from a first end of the quill 104 to a second end of the quill 104 opposite the first end of the quill 104. The first end of the quill 104 is proximal to the guide body 102 and distal to the workpiece 20, while the second end of the quill 104 is distal to the guide body 102 and proximal to the workpiece 20.

[0040] The guide tip 150 can be attached to the second end of the quill 104 via a connector portion 152 of the guide tip 150 having threads 154 or the like. The quill 104 and the guide tip 150 can have a common centerline CL, which can also be shared by the electrode passage 108, the electrode receptacle 110, the bolt 112, the spacer tube 114, and the electrode guide tube 118, as well as the electrode 18. With further reference to FIG. 4 , the guide tip 150 can include a lower passage 156 defined therein that is in fluid communication with an upper passage 120 in the quill 104, defined between the hollow body 105 and the electrode 18 or the electrode guide tube 118, respectively. A dielectric fluid can thereby flow from the upper passage 120 into the lower passage 156 and through the lower passage 156 to an outlet end 166 of the guide tip 150. The electrode 18 can pass through an electrode passage 108 of the guide tip defined through, for example, the center of the guide tip 150, and in embodiments, the electrode 18 can be guided within an electrode guide tube 118 provided within the electrode passage 108 of the guide tip. The lower channel 156 thus provides a dielectric fluid passage for the guide tip defined around the electrode passage 108. The main portion 158 of the guide tip 150 can extend from the connector portion 152 to an outlet end 166 of the guide tip 150. A shoulder 157 ( FIG. 4 ) of the main portion 158 can abut against the second end of the hollow body 105 of the quill 104 when the connector portion 152 is attached to the second end of the quill 104, such as when the connector portion 152 is threaded into the second end of the hollow body 105 using the threads 154.

[0041] With continued reference to FIGS. 2 and 3 , and with reference to the enlarged views in FIGS. 4 and 5 , the main portion 158 can include an inner body 160 through which the electrode 18 passes. In embodiments including the inner body 160, the main portion 158 can be said to define an outer body 165 between its outer surface and an inner wall 170. The inner body 160 includes an electrode guide 162 at the connector portion 152, which has an entrance with an inner diameter larger than the outer diameter of the electrode 18, or, if present, the electrode guide tube 118, and which tapers axially toward the electrode passage 108 (see FIG. 5 ) in the guide tip 150. Space is left in the electrode passage 108 for the electrode 18 or electrode guide tube 118 to travel in. Standoffs or supports 164 can be positioned between the outer wall 168 of the inner body 160 and the inner wall 170 of the main portion 158 to retain the inner body 160 within the guide tip 150. As particularly seen in Figure 4, multiple groups of supports 164 can be included, such as an upper group illustrated to the right of guide tip 150 above lower flow passage 156, and a lower group. As shown in Figure 4, one or more groups of supports 164 can be circumferentially offset from one another, as illustrated by the upper supports 164 being cross-sectioned while the lower group of supports 164 are not cross-sectioned. Together, outer wall 168 of inner body 160 and inner wall 170 of main portion 158 can define lower flow passage 156 within main portion 158.

[0042] As can be seen particularly in FIG. 4 and especially in the additionally enlarged FIG. 5 , the funnel portion 172 of the main portion 158 can begin a shift distance C away from the exit end 166 of the guide tip 150. At the shift distance C, the slope of the inner wall 170 of the main portion 158 can change to a first angle α relative to the centerline CL of the guide tip 150. In embodiments, the slope of the outer wall 168 of the inner body 160 can remain unchanged at the funnel portion 172, while in other embodiments, the outer wall 168 of the inner body 160 can change slope by a second angle β relative to the centerline CL of the guide tip 150 at the shift distance C. In either case, the first angle α and the second angle β can be selected so that the dielectric fluid exits the exit end 166 of the guide tip 150 with an inward velocity component at an angle θ, also referred to as the “angle of attack” of the exiting dielectric fluid. Thus, the lower channel 156 in the funnel portion 172 may, in embodiments, be cone-shaped and may have a channel thickness t defined between the outer wall 168 of the inner body 160 and the inner wall 170 in the funnel portion 172, and a channel spacing X defined by the outer wall 168 of the inner body 160. In the illustrated embodiment, the channel thickness t remains constant throughout the funnel portion 172, although in other embodiments the channel thickness t may vary (e.g., decrease toward the outlet end 166).

[0043] The funnel portion 172 of the guide tip 150, and in particular the lower passage 156, is thus configured to direct the dielectric fluid toward a focal point F located at a standoff distance S from the end 166 of the guide tip 150, for example, in that the lower passage 156 of the funnel portion is inclined toward the common centerline CL of the quill and guide tip in a direction toward the exit end 166 of the guide tip 150, at a standoff distance S from the machining location 22. For example, the lower passage 156 may be ring-shaped in cross section in the funnel portion 172, or more specifically, may be circular ring-shaped. The average diameter of the ring-shaped cross section, i.e., the arithmetic mean value of the diameters of the inner wall 170 of the main portion 158 of the guide tip 150 or the outer body 165, respectively, and the outer wall 168 of the inner body 160, decreases in a direction toward the exit end 166. The standoff distance S may be a setting of the EDM apparatus 10. For example, the EDM apparatus 10 may be set to maintain a standoff distance of 0.25 inches from the workpiece 20. In embodiments, the channel thickness t, channel spacing X, and angle of attack θ may be selected based on characteristics of the electrode 18, such as the outer diameter of the electrode 18. The channel thickness t, channel spacing X, and angle of attack θ may also be selected to provide laminar flow of the dielectric fluid as it exits the guide tip 150, which may provide more efficient debris removal than non-laminar flow. Additionally, the channel thickness t, channel spacing X, and angle of attack θ may also be selected to ensure that the dielectric fluid is directed toward a focal point F, which, in embodiments, is at the processing location 22. That is, the channel thickness t, channel spacing X, and angle of attack θ may be selected to ensure that a sufficient amount of the dielectric fluid arrives at the standoff distance S, such as by directing the dielectric fluid toward the focal point F.

[0044] The first and second angles α and β may be selected in embodiments to provide a desired angle of attack θ. In embodiments, for example, for an electrode having an outer diameter of 0.039 inches, a standoff distance S of 0.25 inches and a channel thickness t of 0.030 inches may be advantageous. In this example, an inner body wall thickness 180 at end 166 of 0.020 inches and an inner body wall thickness 182 at shift distance C of 0.040 inches were appropriate for the materials used for guide tip 150 and inner body 160. Also, in this example, an angle of attack θ of approximately 20° provided sufficient laminar flow of the dielectric fluid to processing location 22. It should be noted that angle of attack θ, shift distance C, inner body wall thickness, outer body wall thickness, and channel spacing X may vary depending on the electrode outer diameter, as discussed above.

[0045] The funnel portion 172 and the lower passage 156 therein can effectively shape the exiting dielectric fluid into a hollow cone, or alternatively in embodiments, a conical cross-section, having a height of the standoff distance S, an outer diameter at its base approximately equal to the diameter of the inner wall 170 of the main portion 158 at the end 166 (i.e., X+2t, as labeled in FIG. 5 ), and an inner diameter at its base approximately equal to the diameter of the outer wall 168 of the inner body 160 at the end 166 ("X" in FIG. 5 ). The inner and outer surfaces of the hollow cone of dielectric fluid can be spaced apart by a thickness t, at least at the end 166 of the guide tip 150. In embodiments, the inner and outer surfaces of the hollow cone can converge or remain spaced apart depending on the first and second angles α, β, which may be desired and / or suitable for a particular application.

[0046] The through-flush guide 100, or portions thereof, can be manufactured using additive manufacturing (“AM”). In particular, the guide tip 150 is suitable for AM manufacturing using resins, plastics, metals such as sintered metal powder, or other materials compatible with dielectric fluid flushing and EDM. Furthermore, variations of the guide tip 150, such as those with different flow rates, standoff distances D, first and second angles α and β, angle of attack θ, channel thickness t, wall thickness, and other variables, can be fabricated and stored near the electrical discharge machining apparatus 10. A user can exchange one variation of the guide tip 150 for another if a task requires a guide tip 150 with different characteristics. The guide tip 150 can include an attachment mechanism (e.g., threads) to facilitate easy engagement and removal from the quill 104.

[0047] As described herein, conventional approaches and systems for FHD EDM fail in at least one aspect, particularly in some cases, resulting in reduced cutting progress during periods near breakthrough. In comparison to these conventional approaches and systems, various embodiments described herein enhance debris removal during FHD EDM by directing dielectric fluid toward the machining location 22 in a more focused or focused manner using through-flushing and jet-flushing aspects. The guide tip 150 receives dielectric fluid from a removably attached quill 104. The guide tip includes one or more channels that deliver dielectric fluid from the quill end of the guide tip to the workpiece end of the guide tip. The channels are configured to deliver dielectric fluid to the machining location more directly than prior art devices. In embodiments, for example, as seen particularly in FIG. 5 , the channels 156 may be annular with a constant thickness and parallel to the surface of the quill 104 from the working end 166 of the guide tip 150 to the shift distance S. In other embodiments, the thickness and / or orientation of the channels may vary. In any event, over the shift distance S, the outer diameter OD of the flow channel 156 may decrease as the flow channel approaches the working end 166 of the guide tip 150. This decrease in outer diameter OD may impart an angle α to the outer wall of the flow channel 156 so that the dielectric fluid exits the working end 166 of the guide tip 150 at a desired angle θ. Over the shift distance S, the inner diameter of the flow channel 156 may remain unchanged or may decrease as the flow channel approaches the working end 166 of the guide tip 150. In some embodiments, the thickness t of the flow channel may remain constant as a result of the appropriate decrease in inner diameter ID, while in other embodiments, the thickness t may decrease and in other embodiments, the thickness t may increase.

[0048] It should be noted that the behavior of the cross-sectional area of ​​the flow channel over the shift distance S can affect the delivery of the dielectric fluid. For example, if the cross-sectional area remains constant, the velocity of the dielectric fluid will not change, but if the cross-sectional area decreases, the dielectric fluid will accelerate as it moves through the flow channel 156 and may exit at a higher velocity than the dielectric fluid that was present in the flow channel 156 at the shift distance S. If the cross-sectional area of ​​the flow channel increases over the shift distance S, the velocity of the dielectric fluid will decrease as it approaches the end 166 of the guide tip 150. In various embodiments, the slope of the flow channel outer diameter OD, the slope of the flow channel inner diameter ID, angle α, angle θ, thickness t, and shift distance S are selected to deliver the dielectric fluid to the processing location 22 for beneficial debris removal and cooling of the electrode 18 and workpiece 20.

[0049] A comparison of the performance of a conventional apparatus and a through-flush guide 100 according to an exemplary embodiment of the present disclosure can be seen in FIGS. 6A-6C using hole progress graphs showing hole depth (millimeters) versus time (minutes). A common workpiece 20 and desired hole size were used in each trial shown in FIGS. 6A-6C. FIG. 6A shows hole drilling progress using a conventional flush system in which dielectric fluid is delivered to the drilling site along the outer surface of the electrode guide tube. As can be seen, progress becomes erratic just before four minutes, effectively indicating the onset of pre-breakthrough (PBT) and providing a means for pre-breakthrough detection (PBTD). As can be seen in FIG. 6A, along-the-tube flushing makes no progress for two minutes before continuing toward breakthrough (BT) and hole completion. FIG. 6B shows hole progress using a conventional through-flush guide, showing reduced periods of erratic behavior but still little progress for approximately one minute. 6C shows the progression of the hole using embodiments disclosed herein, clearly demonstrating the near elimination of the erratic pre-breakthrough behavior of conventional arrangements. Furthermore, the time to pre-breakthrough is reduced by nearly one minute, and the time to hole completion is reduced by more than two minutes, from over six minutes using an external tube flash according to embodiments disclosed herein to approximately 3.5 minutes using a through-flush guide according to embodiments disclosed herein. Thus, the technical effect of embodiments of the present disclosure is to improve FHD EDM performance by more completely directing the dielectric fluid with guide tip 150 to machining location 22, thereby increasing debris removal and reducing hole completion time.

[0050] Approximate terms used throughout this specification and claims may be applied to modify any quantitative expression that can be permissibly varied without resulting in a change in the basic function to which it relates. Accordingly, values ​​modified by terms such as "about," "approximately," and "substantially" are not limited to the exact value specified. In at least some instances, approximate terms may correspond to the precision of the instrument used to measure the value. Throughout this specification and claims, range limitations may be combined and / or interchangeable. Such ranges are specified and include all subranges contained therein, unless the context or language indicates otherwise. "About" or "approximately," as applied to a particular value in a range, applies to both endpoints and may indicate ±10% of the stated value, unless dependent on the precision of the instrument used to measure the value.

[0051] Corresponding structure, materials, acts, and equivalents of all means- or step-plus-function elements in the following claims are intended to include any structure, material, or acts for performing a function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limiting to the disclosure in the form disclosed. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the present disclosure. The embodiments were chosen and described to best explain the principles of the disclosure and practical application of such techniques, and to enable those skilled in the art to appreciate various embodiments of the disclosure and various possible modifications of the disclosed embodiments as suited to the particular use(s) contemplated. [Explanation of symbols]

[0052] 10: Electrical discharge machining apparatus 12: Mast 14: Work platform 16: Electrode supply system 18: Electrode 20: Workpiece 22: Machining location 24: Dielectric fluid supply 26: Conduit 100: Through-flush guide 102: Guide body 104: Quill 105: Hollow body 106: Dielectric fluid passage 108: Electrode passage 110: Electrode holder 112: Bolt 114: Spacer tube 115: Thread 116: Joint 118: Electrode guide tube 120: Upper passage 150: Guide tip 152: Connector 154: Thread 156: Lower passage 157: Shoulder 158: Main section 160: Inner body 162: Electrode guide 164: Support 165: Outer body 166: Outlet end / working end 168: Outer wall 170: Inner wall 172: Funnel section 180, 182: Wall thickness α: First angle β: Second angle θ: Angle of attack C: Shift distance CL: Common center line D, S: Standoff distance F: Focus OD: Outside diameter t: Passage thickness X: Passage spacing

Claims

1. A through-flash guide (100) for high-speed drilling electrical discharge machining, comprising: A guide body (102); a quill (104) having a hollow body (105), the quill having a first end and a second end opposite the first end, the first end attached to the guide body (102) and configured to receive and transport an electrode (18) of the electrical discharge machining device, the quill (104) configured to receive and transport a dielectric fluid from the first end of the quill to the second end of the quill; a guide tip (150) provided at the second end of the quill; Including, The quill (104) and the guide tip (150) have a common centerline (CL); the guide tip includes an electrode passage (108) defined along the common centerline and a lower channel (156) providing a dielectric fluid passage for the guide tip (150) defined around the electrode passage; A through-flush guide, wherein the lower flow channel (156) in the funnel portion (172) of the guide tip is configured to direct the dielectric fluid toward a focal point (F) located a standoff distance (S) away from the outlet end (166) of the guide tip.

2. 2. The through flash guide of claim 1, wherein the guide tip has a main portion having an inner wall and an inner body, the electrode passage in the guide tip being defined along a center of the inner body, and the lower flow passage providing the dielectric fluid passage in the guide tip being defined between an outer wall of the inner body and the inner wall of the main portion.

3. 3. The through flash guide of claim 2, wherein the funnel portion begins a shift distance away from the outlet end of the guide tip in a direction toward the outlet end of the guide tip, and wherein a slope of the inner wall of the main portion changes at the shift distance to a first angle relative to the common centerline of the guide tip and the quill.

4. 4. The through flash guide of claim 3, wherein the funnel portion begins a shift distance (C) away from the outlet end (166) of the guide tip in a direction toward the outlet end (166) of the guide tip, and wherein a slope of the outer wall (168) of the inner body (160) changes to a second angle (β) relative to the centerline of the guide tip over the shift distance.

5. The through flash guide of claim 4 , wherein the second angle and the first angle are equal.

6. The through-flush guide of claim 1 , wherein the lower passage (156) providing the dielectric fluid passage at the guide tip is conical in the funnel portion.

7. 2. The through-flush guide of claim 1, wherein the lower passage (156) providing the dielectric fluid passage of the guide tip is inclined relative to the common centerline (CL) of the quill and the guide tip at the funnel portion (172) of the guide tip in a direction toward the outlet end (166) of the guide tip.

8. The through flash guide of claim 1 , further comprising an electrode guide tube (118) within the quill (104) and concentric with the quill (104), the electrode guide tube configured to receive an electrode (18).

9. The through-flash guide of claim 1 , wherein the guide body (102) is configured to be attached to the electrical discharge machining device (10).

10. The through flash guide of claim 1 , wherein the guide body (102) includes a mounting end configured for attachment to the electrical discharge machining device and a distal end opposite the mounting end.

11. The through flash guide of claim 2 , further comprising a plurality of supports (164) extending between the outer wall (168) of the inner body (160) and the inner wall (170) of the main portion (158).

12. The through-flush guide of claim 1 , wherein the guide body dielectric fluid passage (106) is defined within and extends through the guide body (102).

13. The through-flush guide of claim 1 , wherein the dielectric fluid passage (106) of the guide body includes a connection configured to route dielectric fluid to an interior of an electrode.

14. An electric discharge machining device (10), a working platform (14); a mast (12) extending above the work platform; an electrode supply system (16); a dielectric fluid supply (24); and a through-flash guide (100) according to any one of claims 1 to 13 attached to the mast (12).

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