Through flushing guide for rapid drilling with electrical discharge machining system

Abstract

A through-flush guide (100) having a sleeve (104) extending from a mast (12) attached to an electrical discharge machining apparatus (10) towards a work platform (14). An electrode (18) of an electrical discharge machining device extends through the sleeve to the work stage. The sleeve includes a dielectric fluid channel surrounding the electrode (18). A guide tip (150) on the sleeve receives the dielectric fluid and directs it at a focal point (F) at a distance (S) from an end of the guide tip.

Description

Technical Field

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

[0002] During FHD, an EDM electrode is used to erode material from a metal workpiece in a compact, circular area, thereby creating a hole in the workpiece. The electrode is fed through a guide comprising a horizontal guide body that holds a vertical, hollow sleeve positioned above the workpiece. The end of the sleeve is positioned away from the workpiece, with the tip of the electrode protruding toward a work location on the workpiece. A spark or plasma channel between the electrode tip and the workpiece converts at least some of the metal in the workpiece into plasma, eroding the material at the work location. As the material is eroded, the electrode is fed into the resulting cavity to create a generally cylindrical borehole in the workpiece. Due to the erosion of the workpiece material and the consumption of electrode material, metal debris may accumulate in the hole, which may hinder the progress of hole formation. For example, the presence of debris may cause arcing between the electrode and the workpiece, such as arcing through the debris.

[0003] In order to reduce the accumulation of debris, the EDM system can include a flushing arrangement in which a liquid is delivered to the hole to flood the hole and the accumulated material is taken away from the working position. Typically, a dielectric fluid (such as water or dielectric oil) is used as a flushing liquid, which is widely referred to as "dielectric fluid" in this article. It should be understood that the term "dielectric fluid" is not limited to the examples provided above, but can also include any suitable dielectric fluid that is now known or later found to be suitable. Some flushing arrangements use so-called "jet flushing," also known as "side flushing," in which a nozzle or opening guides the dielectric fluid to the working position. However, this is not as accurate as, for example, pressure flushing (also known as jet flushing) in FHD. Pressure flushing is a common flushing technique in which a pressurized dielectric fluid is provided to the working position. Two main types of pressure flushing are used: through-workpiece and through-electrode ("through-flushing"). During through-flushing, the dielectric fluid delivered by the electrode leaves the tip of the electrode at the working position, floods the working position, and then flows out of the working position. The dielectric fluid can then take the debris away from the working position while cooling the electrode and workpiece at the working position.

[0004] One factor in the beneficial effects of flushing lies in the design of the electrodes used. In through-flushing, the electrodes are hollow and have an outer diameter that determines the diameter of the hole they can drill. The electrodes can have a single channel or multiple channels through which the dielectric fluid can be delivered. The number of channels an electrode has and the ratio of its inner diameter to its outer diameter determine its durability and the drilling speed it can achieve. Generally, drilling speed varies directly with the value of the ratio, while wall thickness, electrode durability, and taper vary inversely with the value of the ratio. That is, electrodes with thinner walls can drill faster with a smaller taper, but they also wear faster than electrodes with thicker walls.

[0005] In FHD, single-channel electrodes are advantageous because they produce better performance than other designs. However, prior art devices for through-flushing in single-channel electrodes can still result in more debris remaining in the hole than desired, particularly when the electrode approaches the far surface of the workpiece during the pre-penetration period of machining. This reduces cutting efficiency, resulting in slow progress until the electrode finally penetrates the far surface of the workpiece. To attempt to address this issue, hybrid flushing arrangements have been used with varying degrees of success. For example, combining through-flushing with jet flushing can improve results. However, even hybrid systems can experience slowed cutting progress during the near-penetration period. Summary of the Invention

[0006] All aspects, examples and features mentioned below can be combined in any technically possible way.

[0007] One aspect of the present disclosure provides a through-irrigation guide for fast hole drilling (“FHD”) electrical discharge machining (“EDM”), the through-irrigation guide comprising: a guide body. The guide body is particularly configured for attachment to an EDM device. The guide body particularly includes a mounting end configured for attachment to the EDM device. The irrigation guide also includes a cannula having a hollow body, the cannula having a first end and a second end opposite the first end, wherein the first end is mounted on the guide body and is configured to receive and convey an electrode of the EDM device, and wherein the cannula is configured to receive a dielectric fluid and convey the dielectric fluid around the electrode from the first end of the cannula to the second end of the cannula; and a guide tip located on the second end of the cannula, wherein the cannula and the guide tip have a common centerline, the guide tip including an electrode channel defined along the centerline and a dielectric fluid channel defined around the electrode channel, wherein a funnel portion of the guide tip is configured to direct the dielectric fluid toward a focal point located a distance from a distal end of the guide tip.

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

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

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

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

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

[0013] Another aspect of the disclosure includes any of the preceding aspects and wherein the electrode channel of the lead tip is larger at its entrance than at the distal end of the lead tip.

[0014] Another aspect of the present disclosure includes any of the preceding aspects, further comprising an electrode guide tube within and concentric with the cannula, wherein the electrode guide tube is configured to receive an electrode.

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

[0016] One aspect of the present disclosure provides a through-irrigation guide for performing FHD using an EDM device, comprising: a guide body having a mounting end configured to be attached to the EDM device and a distal end opposite the mounting end; a cannula having a hollow body, the cannula having a first end mounted on the guide body and a second end opposite the first end; a guide tip located on the second end of the cannula, wherein the cannula and the guide tip have a common centerline; and an electrode channel defined in the guide body and extending along the centerline. a dielectric fluid channel defined in the lead body, the cannula, and the lead tip and extending therethrough to the distal end of the lead tip, wherein the dielectric fluid channel surrounds the electrode channel in the cannula and the lead tip, and wherein a funnel portion of the lead tip defines the dielectric fluid channel to deliver dielectric fluid to a focal point located a distance from the distal end of the lead tip.

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

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

[0019] Another aspect of the present disclosure includes any of the preceding aspects and wherein a plurality of supports extend between an 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 lead body includes a connection configured to deliver the dielectric fluid to the interior of the electrode.

[0021] One aspect of the present invention provides an electrical discharge machining (EDM) device, comprising: a work platform; a mast extending above the work platform; an electrode feeding system; a dielectric fluid supplier; and a guide for an electrode of the EDM device, the guide comprising: a guide body mounted on the mast of the EDM device; a sleeve having a hollow body, the sleeve having a first end mounted on the guide body and a second end opposite to the first end; and a guide tip located on the second end of the sleeve, the sleeve and the guide tip having a common centerline, wherein the guide body is configured to convey an electrode from the electrode feeding system to the sleeve and to feed the dielectric fluid to the sleeve. An electrical fluid is delivered to the cannula from a fluid supply, wherein the first end of the cannula is configured to receive the electrode and deliver the electrode along the centerline to the lead tip, and the cannula is configured to receive a dielectric fluid around the electrode and deliver the dielectric fluid from the first end of the cannula to the lead tip, and wherein the lead tip includes an electrode channel defined along the centerline and configured to receive the electrode from the cannula, the lead tip further including a dielectric fluid channel defined around the electrode channel, and a funnel portion of the lead tip is configured to direct the dielectric fluid toward a focal point located a distance from a distal end of the lead tip.

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

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

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

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

[0026] Another aspect of the disclosure includes any of the preceding aspects and wherein the lead tip electrode channel is larger at its entrance than at the distal end of the lead tip.

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

[0028] The details of one or more implementations are set forth in the drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] These and other features of the present disclosure will be more readily understood from the following detailed description of various aspects of the present disclosure taken in conjunction with the accompanying drawings which depict various embodiments of the present disclosure, in which:

[0030] Figure 1 is a schematic side view of an EDM apparatus using a through-irrigation guide according to an embodiment of the present disclosure;

[0031] Figure 2 is a schematic cross-sectional view of a through irrigation guide according to an embodiment of the present disclosure;

[0032] Figure 3 It is based on Figure 2 a schematic exploded view of a through irrigation guide of an embodiment of the present disclosure as seen in FIG;

[0033] Figure 4 is an enlarged schematic cross-sectional view of a guide tip of a through-irrigation guide according to an embodiment of the present disclosure;

[0034] Figure 5 According to the embodiment of the present disclosure Figure 4 Another enlarged schematic cross-sectional view of the guide tip;

[0035] Figure 6A and Figure 6B is a schematic diagram illustrating the performance of an EDM device using a prior art flushing arrangement; and

[0036] Figure 6C is a schematic diagram of the performance of an EDM device using a through-irrigation guide according to an embodiment of the present disclosure.

[0037] It should be noted that the drawings of the present disclosure are not necessarily drawn to scale. The drawings are intended to depict only typical aspects of the present disclosure and therefore should not be considered to limit the scope of the present disclosure. In the drawings, similar numbers represent similar elements between the drawings. DETAILED DESCRIPTION

[0038] First, in order to clearly describe the current technology, it will be necessary to select certain terms when referring to and describing relevant machine components within an illustrative application of a through flush guide for fast hole drilling (FHD) using electrical discharge machining (EDM). In doing so, common industry terms will be used and adopted, where possible, in a manner consistent with their accepted meaning. Unless otherwise indicated, such terms should be given a broad interpretation consistent with the context of this application and the scope of the appended claims. One of ordinary skill in the art will understand that several different or overlapping terms may often be used to refer to a particular component. An object that may be described herein as a single part may include multiple components and be referenced in another context as consisting of multiple components. Alternatively, an object that may be described herein as comprising multiple components may be referred to elsewhere as a single part.

[0039] In addition, some descriptive terms can be used regularly in this article, and defining these terms at the beginning of this section should prove to be helpful.Unless otherwise stated, these terms and their definition are as follows.As used herein, "downstream" and "upstream" are terms indicating the direction relative to the flow of fluid, such as a dielectric fluid passing through an EDM device or through one of the EDM device component systems.The term "downstream" corresponds to the direction of fluid flow, and the term "upstream" refers to the direction opposite to flow (i.e., the direction in which flow is emitted).

[0040] In addition, several descriptive terms may be used regularly herein, as described below. The terms "first," "second," and "third" may be used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of individual components.

[0041] The terms used herein are only used to describe the purpose of specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. It will be further understood that when used in the specification, the terms "comprise" and / or "comprising" specify the presence of stated features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or their groups. "Optional" or "optionally" means that the event or situation described subsequently may or may not occur, or the parts or elements described subsequently may or may not exist, and the description includes instances in which the event occurs or the parts exist and instances in which the event does not occur or the parts do not exist.

[0042] When an element or layer is referred to as being "on," "engaged to," "connected to," "coupled to," or "mounted to" another element or layer, it may be directly on, engaged to, connected to, coupled to, or mounted to another element or layer, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on," "directly engaged to," "directly connected to," or "directly coupled to" another element or layer, there may be no intervening elements or layers. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. The verb forms "couple" and "mount" are used interchangeably herein.

[0043] As noted above, and with reference to the attached Figures 1 to 6C , the present disclosure provides a through-flushing guide for FHD EDM. Figure 1 As shown schematically, 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 that is configured for attachment to the mast 12. The mast 12 may also include an electrode feed system (or supply arrangement) 16 that provides an electrode 18 for EDMing a workpiece 20 at a work location 22 on the workpiece 20. As is known in the art, the electrode 18 may be a solid wire or hollow with one or more channels extending along its length. For FHD, the electrode 18 preferably has a single channel extending therethrough, but any suitable electrode configuration may be used with embodiments as disclosed herein. Figure 1 1 and 2. As also schematically shown in FIG, a dielectric fluid supply 24 may be included and connected to the through-flow irrigation guide 100 via a conduit 26 or the like. For example, the conduit 26 may be connected to a dielectric fluid passage 106 defined in the guide body 102 of the through-flow irrigation guide 100, which may then direct the dielectric fluid through a sleeve 104 mounted on the guide body 102 and to the work site 22. The guide body 102 may be configured for attachment to the mast 12 or other portion of the EDM device 10 in any suitable manner known now or in the future.

[0044] like Figure 2 Cross-sectional view and Figure 3, the sleeve 104 includes a hollow body 105 having a first (inlet) end mounted on the guide body 102 and a second (outlet) end opposite the first end. The sleeve 104 can be configured to receive and transport the electrode 18 of the EDM device 10 along a centerline CL of the sleeve 104. The guide body 102 can include an electrode receiver 110 located on a top portion thereof, which can be a conical or frusto-conical cavity formed in the head of a bolt 112 or the like. The electrode receiver 110 can have an inlet defined therein that is wider than the outer diameter of the electrode 18. The electrode receiver 110 can also include an electrode channel defined therein that is slightly larger than the outer diameter of the electrode 18.

[0045] The spacer tube 114 can be axially interposed between the bolt 112 and the sleeve 104 and can be connected to the first end of the sleeve 104 via corresponding threads 115 formed on the inner surface of the spacer tube 114 and on the outer surface of the first end of the sleeve 104. The spacer tube 114 can also be coupled to the guide body 102 via a friction fit or by threads (not shown) formed on the outer surface of the spacer tube 114 and the inner surface of the electrode channel. The spacer tube 114 can include a joint 116 ( Figure 2 ). In embodiments, the junction 116 can direct the fluid from the dielectric fluid channel 106 to the sleeve 104. In other embodiments, the junction 116 can also direct the dielectric fluid into and / or along the electrode 18. It should be understood that, in embodiments, features of the electrode receiver 110 and / or the spacer tube 114 can be integrally formed with the guide body 102.

[0046] In an embodiment, the cannula 104 may include an electrode guide tube 118 concentric therewith, through which the electrode 18 may extend. Regardless of whether the cannula 104 includes the electrode guide tube 118, an upper channel 120 may be defined between the inner surface of the cannula 104 and the electrode 18. That is, the cannula 104 may be configured to receive the dielectric fluid around the electrode 18 in the upper channel 120 and to convey the dielectric fluid from a first end of the cannula 104 to a second end of the cannula 104 opposite the first end of the cannula 104. The first end of the cannula 104 is proximal to the guide body 102 and distal to the workpiece 20, while the second end of the cannula 104 is distal to the guide body 102 and proximal to the workpiece 20.

[0047] The guide tip 150 can be mounted on the second end of the cannula 104 via a connector portion 152 of the guide tip 150, such as using threads 154. The cannula 104 and the guide tip 150 can have a common centerline CL, which can also be shared by the electrode channel 108, the electrode receiver 110, the bolt 112, the spacer tube 114, the electrode guide tube 118, and the electrode 18. Figure 4 , the guide tip 150 may include a lower channel 156 defined therein that is in fluid communication with an upper channel 120 defined in the cannula 104 between the hollow body 105 and the electrode 18 or the electrode guide tube 118, respectively. Thus, a dielectric fluid may flow from the upper channel 120 and through the lower channel 156 to the outlet end 166 of the guide tip 150. The electrode 18 may pass along the center of the guide tip 150, such as in an electrode channel 108 of the guide tip defined along its center, wherein the electrode 18 may be guided in an electrode guide tube 118 disposed within the electrode channel 108 of the guide tip in an embodiment. Thus, the lower channel 156 provides a dielectric fluid passage around the guide tip defined by the electrode channel 108. The main portion 158 of the guide tip 150 may extend from the connector portion 152 to the outlet end 166 of the guide tip 150. When the connector portion 152 is mounted on the second end of the sleeve 104, for example when the connector portion 152 is screwed into the second end of the hollow body 105 using the threads 154, the shoulder 157 ( Figure 4 ) can be adjacent to the second end of the hollow body 105 of the sleeve 104.

[0048] Continue to refer Figure 2 and Figure 3 , and observe Figure 4 and Figure 5 , the main portion 158 may include an inner body 160 through which the electrode 18 may pass. In embodiments including the inner body 160, the main portion 158 may be said to constitute an outer body 165 between its outer surface and the inner wall 170. The inner body 160 includes an electrode guide 162 at the connector portion 152, the electrode guide having an inlet having an inner diameter greater than the outer diameter of the electrode 18 or the electrode guide tube 118 (if present), and the electrode guide toward the electrode channel 108 (see FIG. Figure 5 ) is getting smaller and smaller, that is, gradually tapering in the axial direction. In an embodiment, space is left in the electrode channel 108 for the electrode 18 or the electrode guide tube 118 to move. The legs or supports 164 can be arranged between the outer wall 168 of the inner body 160 and the inner wall 170 of the main part 158 ​​to hold the inner body 160 within the guide tip 150. As shown in Figure 4As particularly seen in FIG, multiple sets of supports 164 may be included, such as an upper set and a lower set shown to the right of the guide tip 150 above the lower channel 156. Figure 4 As shown, one or more sets of supports 164 can be circumferentially offset from one another, as shown, with the lower set of supports 164 not shown in cross-section, while the upper set of supports 164 is shown in cross-section. An outer wall 168 of the inner body 160 and an inner wall 170 of the main portion 158 can collectively define the lower passage 156 in the main portion 158.

[0049] As in Figure 4 and especially in the further amplification Figure 5 As specifically seen in FIG, the funnel portion 172 of the main portion 158 can begin to shift a distance C away from the outlet end 166 of the guide tip 150. At the shift distance C, the inclination 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 an embodiment, the inclination of the outer wall 168 of the inner body 160 can remain unchanged in the funnel portion 172, but in other embodiments, the inclination of the outer wall 168 of the inner body 160 can change to a second angle β relative to the centerline CL of the guide tip 150 at the shift distance C. The first angle α and the second angle β can be equal (thereby creating parallel surfaces), but do not need to be equal. In any case, the first angle α and the second angle β can be selected so that the dielectric fluid exits the outlet end 166 of the guide tip 150 at an angle θ (also known as the "angle of attack" of the exiting dielectric fluid) and with an inwardly directed velocity component. Thus, in an embodiment, the lower channel 156 in the funnel portion 172 can be frusto-conical and can 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 embodiment shown, the channel thickness t remains constant throughout the funnel portion 172, but in other embodiments, the channel thickness t can vary (e.g., decrease toward the outlet end 166).

[0050] Thus, the funnel portion 172 of the guide tip 150, and in particular, the lower passage 156, is configured to direct the dielectric fluid toward a focal point F located at a distance S from the end 166 of the guide tip 150. For example, the lower passage 156 in the funnel portion is inclined toward the common centerline CL of the cannula and the guide tip in a direction toward the outlet end 166 of the guide tip 150, such as the distance from the workpiece 22. For example, the lower passage 156 can be annular in cross-section within the funnel portion 172, and more specifically, circular in cross-section. The average diameter of the annular cross-section, i.e., the arithmetic mean of the diameters of the inner wall 170 of the main portion 158 of the guide tip 150 or outer body 165 and the outer wall 168 of the inner body 160, respectively, decreases in a direction toward the outlet end 166. The standoff distance S can be a setting of the EDM device 10. For example, the EDM device 10 can be configured to maintain a standoff distance of 0.25 inches from the workpiece 20. In an embodiment, channel thickness t, channel spacing X, and angle of attack θ can be selected based on the characteristics of electrode 18 (such as the outer diameter of electrode 18). Channel thickness t, channel spacing X, and angle of attack θ can also be selected to provide laminar flow when the dielectric fluid leaves the guide tip 150, which can more effectively remove debris than non-laminar flow. In addition, channel thickness t, channel spacing X, and angle of attack θ can also be selected to ensure that the dielectric fluid is aimed at the focal point F, which in an embodiment will be at the working part 22. That is, channel thickness t, channel spacing X, and angle of attack θ can be selected to ensure that a sufficient amount of dielectric fluid arrives at a distance S apart, such as by directing the dielectric fluid to the focal point F.

[0051] In an embodiment, the first angle α and the second angle and β can be selected to produce the desired angle of attack θ. In an embodiment, for example, for an electrode with an outer diameter of 0.039 inch, a distance S of 0.25 inch and a channel thickness t of 0.030 inch can be advantageous. In this example, considering the material for guide tip 150 and inner body 160, an inner body wall thickness 180 of 0.020 inch at end 166 and an inner body wall thickness 182 of 0.040 inch at a displacement distance C are suitable. In addition, in this example, the angle of attack θ of approximately 20 ° provides enough dielectric fluid laminar flows to the working part 22. It should be noted that angle of attack θ, displacement distance C, inner body wall thickness, outer body wall thickness and channel spacing X can change according to electrode outer diameter as described above.

[0052] The funnel portion 172 and the lower channel 156 therein can effectively shape the discharged dielectric fluid into a hollow cone, or alternatively, in embodiments, into a frustoconical segment having a height separated by a distance S and an outer diameter at the base approximately equal to the diameter of the inner wall 170 of the main portion 158 at the end 166 (i.e., as shown in FIG. Figure 5, which is X+2t), and whose inner diameter at the base is approximately equal to the diameter of the outer wall 168 of the inner body 160 at the end 166 ( Figure 5 ). The inner and outer surfaces of the hollow cone of dielectric fluid can be separated by at least a thickness t 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 and β and as may be desired and / or suitable for a particular application.

[0053] The through-irrigation guide 100 or portions thereof can be made using additive manufacturing ("AM"). In particular, the guide tip 150 is suitable for being manufactured using AM using resin, plastic, metal (such as sintered metal powder), or any other material compatible with dielectric fluid flushing and EDM. In addition, variations of the guide tip 150, such as having different flow rates, standoff distances D, first and second angles α and β, angles of attack θ, channel thickness t, wall thickness, and other variables, can be made and maintained near the EDM device 10. If the task requires a guide tip 150 having different characteristics, the user can exchange one variation of the guide tip 150 for another. The guide tip 150 can be provided with an attachment mechanism (e.g., threads) that facilitates easy engagement with and removal from the cannula 104.

[0054] As described herein, conventional methods and systems for FHD EDM fail in at least one aspect and, in certain circumstances, may experience slowed cutting progress during the near-penetration period. Relative to those conventional methods and systems, the various embodiments described herein enhance debris removal during FHD EDM by directing the dielectric fluid to the work site 22 in a more intensive or focused manner using aspects of through-flush and jet-flush. The guide tip 150 receives the dielectric fluid from the cannula 104 to which the guide tip is removably attached. The guide tip includes one or more channels that convey the dielectric fluid from the cannula end of the guide tip to the working end of the guide tip. The channels are shaped to deliver the dielectric fluid to the work site more directly than prior art devices. In an embodiment, for example, as in Figure 5As particularly seen in FIG, the channel 156 can be annular with a constant thickness and parallel to the surface of the cannula 104 until a displacement distance S from the working end 166 of the guide tip 150. In other embodiments, the channel thickness and / or orientation can vary. In any case, at the displacement distance S, the outer diameter OD of the channel 156 can decrease as the channel approaches the working end 166 of the guide tip 150. This reduction in outer diameter OD can impart an angle α to the outer wall of the channel 156, causing the dielectric fluid to exit the working end 166 of the guide tip 150 at a desired angle θ. Over the displacement distance S, the inner diameter of the channel 156 can remain constant or can also decrease as the channel approaches the working end 166 of the guide tip 150. In some embodiments, due to the appropriate reduction in inner diameter ID, the thickness t of the channel can remain constant, while in other embodiments, the thickness t can decrease, and in other embodiments, the thickness t can increase.

[0055] It should be noted that the behavior of the cross-sectional area of ​​the channel on the displacement distance S may affect the delivery of the dielectric fluid. For example, if the cross-sectional area remains constant, the speed of the dielectric fluid should remain unchanged, and if the cross-sectional area is reduced, the dielectric fluid can be accelerated when it travels through the channel 156, leaving at a speed higher than the dielectric fluid at the displacement distance S in the channel 156. If the channel cross-sectional area increases on the displacement distance S, the dielectric fluid speed will decrease as it approaches the end 166 of the guide tip 150. In various embodiments, the slope of the channel outer diameter OD, the slope of the channel inner diameter ID, angle α, angle θ, thickness t and the displacement distance S are selected to deliver the dielectric fluid to the working position 22 to advantageously remove debris and cool the electrode 18 and the workpiece 20.

[0056] exist Figures 6A to 6C A comparison of the performance of a conventional device and a through irrigation guide 100 according to an exemplary embodiment of the present disclosure can be seen using a graph of hole progress in FIG, which shows the relationship between hole depth (in millimeters) and time (in minutes). Figures 6A to 6C A common workpiece 20 and desired hole size were used in each of the experiments shown. Figure 6A The hole progress using a conventional irrigation system is shown, where the dielectric fluid is delivered to the working site along the outside of the electrode guide tube. It can be seen that the progress becomes unstable just before reaching 4 minutes, effectively indicating the disadvantages of pre-penetration (PBT) and showing the method of pre-penetration detection (PBTD). Figure 6A As can be seen, there is no progress in flushing along the tube for 2 minutes before continuing towards breakthrough (BT) and completing the borehole. Figure 6B The hole progress using a conventional through-irrigation guide is shown, which, while exhibiting reduced periods of erratic behavior, still shows little progress over approximately one minute. Figure 6CThe hole progress using the embodiments disclosed herein is shown, and clearly demonstrates that the unstable pre-penetration behavior of conventional arrangements has been virtually eliminated. Furthermore, the pre-penetration time was reduced by nearly a minute, and the time to complete the hole was reduced by over two minutes, from over 6 minutes using external tube flushing to approximately 3.5 minutes using the through-flush guide according to the embodiments disclosed herein. Thus, the technical effect of the embodiments disclosed herein is to improve FHD EDM performance by more completely directing the dielectric fluid into the work site 22 using the guide tip 150, thereby improving debris removal and reducing hole completion time.

[0057] As used throughout the specification and claims, approximating language may be used to modify any quantitative representation that can be permissibly varied without resulting in a change in the basic function to which it relates. Accordingly, a value modified by one or more terms, such as "about," "approximately," and "substantially," is not limited to the precise value specified. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value. Here and throughout the specification and claims, range limitations may be combined and / or interchanged; unless the context or language indicates otherwise, these ranges are identified and include all subranges contained therein. "About" or "approximately" applied to a particular value of a range applies to both end values ​​and, unless otherwise dependent on the precision of the instrument for measuring the value, may indicate + / - 10% of the stated value.

[0058] The corresponding structures, materials, actions, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or action for performing the function in combination with other claimed elements specifically claimed. The description of the present disclosure has been given for the purposes of illustration and description, but it is not intended to be exhaustive or to limit the disclosure to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the present disclosure. The embodiments are selected and described in order to best explain the principles of the present disclosure and practical applications of such technologies, and to enable others skilled in the art to understand the various embodiments of the present disclosure and various modifications of the disclosed embodiments that may be suitable for the specific purposes envisioned.

Claims

1. A through-flushing guide (100) for rapid drilling electrical discharge machining, the through-flushing guide comprising: a guide body (102); a cannula (104) having a hollow body (105), the cannula having a first end and a second end opposite the first end, wherein the first end is mounted on the guide body (102) and is configured to receive and deliver an electrode (18) of an EDM device, and wherein the cannula (104) is configured to receive a dielectric fluid and deliver the dielectric fluid from the first end of the cannula to the second end of the cannula; and A guide tip (150) is positioned on the second end of the cannula, wherein the cannula (104) and the guide tip (150) have a common centerline (CL), the guide tip including an electrode channel (108) of the guide tip defined along the common centerline and a lower channel (156) providing a dielectric fluid channel of the guide tip (150) defined around the electrode channel, wherein in a funnel portion (172) of the guide tip, the lower channel (156) is configured to direct dielectric fluid toward a focal point (F) located a distance (S) from an outlet end (166) of the guide tip.

2. A through-irrigation guide according to claim 1, wherein the guide tip (150) has a main portion (158) having an inner wall (170) and an inner body (160), wherein the electrode channel (108) of the guide tip is defined along the center of the inner body, and the lower channel (156) providing the dielectric fluid passage of the guide tip is defined between the outer wall (168) of the inner body (160) and the inner wall (170) of the main portion (158).

3. A through-irrigation guide according to claim 2, wherein the funnel portion (172) begins a displacement 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 the inclination of the inner wall (170) of the main portion (158) changes to a first angle (α) relative to the common centerline (CL) of the guide tip and the cannula at the displacement distance.

4. A through-flushing guide according to any one of claims 2 or 3, wherein the funnel portion (172) starts a displacement 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 the inclination of the outer wall (168) of the inner body (160) changes to a second angle (β) relative to the center line of the guide tip at the displacement distance.

5. A through-flush guide according to claim 4 when appended to claim 3, wherein the second angle and the first angle are equal.

6. A through irrigation guide according to any preceding claim, wherein the lower channel (156) providing the dielectric fluid passage of the guide tip is frusto-conical in the funnel portion.

7. A through-irrigation guide according to any preceding claim, wherein the lower channel (156) providing the dielectric fluid passage of the guide tip is inclined towards the common centerline (CL) of the cannula and the guide tip in the funnel portion (172) of the guide tip in a direction towards the outlet end (166) of the guide tip (150).

8. The through-irrigation guide according to any preceding claim, further comprising an electrode guide tube (118) located within and concentric with the cannula (104), wherein the electrode guide tube is configured to receive an electrode (18).

9. The through-flush guide according to any preceding claim, wherein the guide body (102) is configured for attachment to an electrical discharge machining device (10).

10. The through-irrigation guide of any preceding claim, wherein the guide body (102) comprises a mounting end configured for attachment to an electrical discharge machining device and a distal end opposite the mounting end.

11. A through-flushing guide according to claim 2 or any one of claims 1 to 10 as appended thereto, 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. A through-irrigation guide according to any preceding claim, wherein the dielectric fluid passage (106) of the guide body is defined in and extends through the guide body (102).

13. The through-irrigation guide of the preceding claim, wherein the dielectric fluid passage (106) of the guide body comprises a connection configured to deliver dielectric fluid to the interior of an electrode.

14. An electrical discharge machining device (10), comprising: Work platform (14); a mast (12) extending above the work platform; Electrode feeding system (16); a dielectric fluid supplier (24); and A through-flushing guide (100) according to any preceding claim, attached to the mast (12).

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