Shell rib mirror image inclined hidden hole electric machining clamping and positioning tool and using method thereof

Abstract

The invention provides a shell rib mirror image inclined hidden hole electric machining clamping and positioning tool and a using method thereof, and belongs to the technical field of electric machining tools. The problem that in the prior art, the requirements for electrode extension adaptation, hole axis orientation and reliable positioning cannot be met at the same time, and consequently the inclined dark hole electric spark machining precision and efficiency are difficult to guarantee is solved. A threaded bushing is in threaded connection with an inclined plane of a supporting base, and a positioning disc coaxially sleeves the outer side of the threaded bushing and is connected with the supporting base; a circular spigot matched with the outer circle of the positioning disc is formed in the lower end face of the conical shell, a fixing spigot is formed in the upper end face of the conical shell, and a pressing plate screw is screwed into an internal thread of the threaded bushing to fix the fastening pressing plate to the fixing spigot of the conical shell; a first L-shaped support and a second L-shaped support are symmetrically arranged on the left side and the right side of the supporting base. The problems that in the prior art, the requirements for electrode extension adaptation, hole axis orientation and reliable positioning cannot be met at the same time, and consequently the inclined dark hole electric spark machining precision and efficiency are difficult to guarantee are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of electrical discharge machining (EDM) tooling technology, and in particular to an EDM clamping and positioning tooling for mirrored oblique dark holes in shell ribs and its usage method. Background Technology

[0002] A certain piece of equipment has a conical shell with three ribs, each with a set of interconnected vent holes, located at the same relative position on the ribs. Each rib has a radial blind hole on its neutral plane passing through the shell axis, which connects to mirrored oblique dark holes on both sides of the rib inside the shell. The radial holes penetrate the exterior of the shell and can be machined. However, due to structural and functional requirements, the mirrored oblique dark holes on both sides of the rib inside the shell are located near the inner conical surface of the shell, blocked by the small-end conical opening, making it a "dead corner" where the drill bit cannot directly penetrate. Therefore, machining is excluded from the process options.

[0003] After process demonstration, it was determined that electrical discharge machining (EDM) technology would be used to achieve the through-hole of the oblique dark hole. However, this process faces two positioning challenges: on the one hand, the radial position dimension of the mirror oblique dark hole is larger than the radius of the small end tapered hole, and the electrode cannot be directly clamped on the EDM machine spindle to reach the machining position. The electrode needs to be extended laterally to the target radial position. On the other hand, the axis of each oblique dark hole to be machined needs to be adjusted to a horizontal state and kept parallel to the X-axis or Y-axis of the machine tool.

[0004] In summary, there is an urgent need to propose a clamping and positioning fixture for EDM of mirrored oblique dark holes in shell ribs, in order to solve the problem that the existing technology cannot simultaneously meet the requirements of electrode extension and adaptation, hole axis orientation and reliable positioning, which makes it difficult to guarantee the accuracy and efficiency of EDM of oblique dark holes. Summary of the Invention

[0005] A brief overview of the invention is given below to provide a basic understanding of certain aspects of it. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0006] In view of this, in order to solve the problem that the existing technology cannot simultaneously meet the requirements of electrode extension adaptation, hole axis orientation and reliable positioning, resulting in difficulty in guaranteeing the accuracy and efficiency of EDM for oblique dark holes, the present invention provides a clamping and positioning fixture for EDM of mirror oblique dark holes of shell ribs and its usage method.

[0007] Option 1: A fixture for clamping and positioning mirrored oblique dark holes in a shell rib during electrical discharge machining, comprising a support base, a positioning plate, a threaded bushing, a pressure plate, pressure plate screws, a first support, a limiting pin, a second support, a conical shell, and an electrode assembly;

[0008] The support base is fixed on the table of the EDM machine tool, and the electrode assembly is fixed on the spindle of the EDM machine tool.

[0009] The threaded bushing is connected to the inclined plane thread of the support base, and the positioning plate is coaxially fitted on the outside of the threaded bushing and connected to the support base; the lower end face of the conical shell is provided with a circular stop that matches the outer circle of the positioning plate, and the upper end face of the conical shell is provided with a fixed stop; the pressure plate screw is screwed into the internal thread of the threaded bushing to fix the fastening pressure plate at the fixed stop of the conical shell.

[0010] The support base is symmetrically provided with L-shaped first support and second support on the left and right sides. The first support and second support are provided with through holes for the limiting shaft pin to pass through. The limiting shaft pin passes through the through hole and is embedded in the reserved hole of the conical shell.

[0011] The electrode assembly includes a clamping rod, an inner extension crossbar, a round bar electrode, and a set screw. The clamping rod and the inner extension crossbar are connected at a 90-degree angle, and the round bar electrode passes through the inner extension crossbar and is fixed by the set screw.

[0012] Furthermore, the conical shell includes ribs, counterclockwise oblique holes, clockwise oblique holes, and connecting holes; the conical shell is provided with three ribs evenly distributed circumferentially, and each rib is provided with one counterclockwise oblique hole, one clockwise oblique hole, and one connecting hole.

[0013] Furthermore, the counterclockwise oblique dark hole and the clockwise oblique dark hole are mirror symmetrical.

[0014] Furthermore, both the counterclockwise oblique dark hole and the clockwise oblique dark hole are connected to the connecting hole.

[0015] Furthermore, the through holes on the first and second supports are coaxial, and their central axes intersect perpendicularly with the axis of the positioning disk.

[0016] Furthermore, the inclination angle of the inclined plane of the support base It is the complementary angle between the counterclockwise oblique dark hole and the clockwise oblique dark hole and the neutral plane of the rib passing through the shell axis.

[0017] Option 2: A method for using a fixture for clamping and positioning mirrored oblique holes in shell ribs during electrical discharge machining, specifically including the following steps:

[0018] S1. First, fix the support base on the EDM machine table, align the left and right sides of the support base so that they are parallel to the "Y" axis of the machine tool; place the conical shell on the positioning plate, adjust the angle of the conical shell so that the rib inside the conical shell rotates to the radial positioning position of the first support, and insert the limiting shaft pin through the through hole on the first support into the connecting hole on the outside of the rib.

[0019] S2. Position the rib in a horizontal position to the left of the X-axis of the machine tool. At this time, the axis of the counterclockwise oblique hole on the rib is rotated to the axis parallel to the horizontal Y-axis of the machine tool, which meets the positioning requirements for horizontal electrical discharge machining of oblique holes. Use the pressure plate and pressure plate screws to lock and fix the position of the conical shell on the support base. At this time, the clamping and positioning preparation for electrical discharge machining of the counterclockwise oblique hole on one rib of the conical shell is completed.

[0020] S3. Extend the round bar electrode on the electrode assembly counterclockwise to the specified length, tighten it with the set screw, fix the clamping rod of the electrode assembly on the machine tool spindle, and make the axis of the round bar electrode parallel to the Y-axis of the machine tool. Start the machine tool spindle for trial feed, move the round bar electrode to the center position of the counterclockwise oblique dark hole, and visually align the round bar electrode with the center of the counterclockwise oblique dark hole reserved when casting the conical shell. Then perform electrical discharge machining on the counterclockwise oblique dark hole.

[0021] S4. There are three ribs inside the conical shell. Each rib has a counterclockwise oblique hole and a clockwise oblique hole in the same relative position. The three ribs are sequentially positioned at the first support position by a limiting shaft pin. The counterclockwise oblique holes on the three ribs are machined respectively.

[0022] S5. After all three counterclockwise oblique holes have been machined, loosen the pressure plate screws, rotate the conical shell along the positioning plate, and use the limit pin to engage with the connecting hole on the outside of the rib to position the three ribs in sequence at the second support position, and machine the clockwise oblique holes on the three ribs in sequence.

[0023] S6. After the three sets of clockwise oblique dark holes are machined, remove the round bar electrode, loosen the pressure plate screws and remove the pressure plate, and take off the conical shell. At this time, the oblique dark hole EDM process of the three ribs on the conical shell is completed.

[0024] The present invention has the following advantages over the prior art:

[0025] 1. This invention, through the left and right radial shaft pin positioning structure on the inclined surface of the support base, can accurately realize the horizontal rotation of the mirror symmetrical oblique dark hole on the same rib of the shell to the required position, and does not need to rely on the consistency of the axial angle of the three ribs. Even if there are differences in the rib angles, it can still be reliably positioned, effectively solving the core orientation problem in EDM where the axis of the oblique dark hole needs to be parallel to the X-axis or Y-axis of the machine tool.

[0026] 2. The present invention does not require changing the overall structure of the electrode assembly. It can adapt to the processing requirements of oblique dark holes in clockwise and counterclockwise directions simply by adjusting the front and rear extension directions of the electrodes. This avoids the need to frequently change electrode assemblies adapted to holes in different directions, reduces tooling adaptation costs, and improves the processing switching efficiency of oblique dark holes in different orientations.

[0027] 3. The inner extension crossbar structure of the electrode assembly in this invention can drive the electrode to extend laterally to the target radial position of the oblique dark hole, successfully breaking through the "dead angle" limitation formed by the small end tapered opening of the housing, solving the key problem that the electrode cannot reach the machining position when directly clamped on the spindle of the EDM machine tool, and ensuring the spatial accessibility of EDM machining of oblique dark holes;

[0028] 4. The invention has a simple overall structure, reducing the maintenance requirements of complex components; the clamping and positioning are reliable and easy to adjust, effectively reducing the skill threshold and setup time for operators, and can stably ensure the machining accuracy and efficiency of oblique dark holes, meeting the industrial batch machining needs of equipment conical shells. Attached Figure Description

[0029] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0030] Figure 1 A schematic diagram of a fixture for clamping and positioning a mirrored oblique dark hole in a shell rib;

[0031] Figure 2 This is a schematic diagram of the electrode assembly.

[0032] Figure 3 This is a schematic diagram of the conical shell structure;

[0033] Figure 4 A diagram showing the positional relationship between ribs, oblique concealed holes, and connecting holes;

[0034] Figure 5 A diagram showing the positional relationship of the device during counterclockwise oblique hole machining;

[0035] Figure 6 This is a diagram showing the positional relationship of the device during clockwise oblique hole machining.

[0036] In the figure: 1-support base, 2-positioning plate, 3-threaded bushing, 4-pressure plate, 5-pressure plate screw, 6-first support, 7-limiting shaft pin, 8-second support, 9-conical shell, 11-clamping rod, 12-inner extension crossbar, 13-round bar electrode, 14-set screw, 91-rib, 92-counterclockwise oblique hole, 93-clockwise oblique hole, 94-connecting hole. Detailed Implementation

[0037] To make the technical solutions and advantages of the embodiments of the present invention clearer, the exemplary embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0038] Example 1, Reference Figure 1-6 This embodiment describes a fixture for EDM (Electrical Discharge Machining) of mirrored oblique dark holes in a housing rib, comprising a support base 1, a positioning plate 2, a threaded bushing 3, a pressure plate 4, a pressure plate screw 5, a first support 6, a limiting pin 7, a second support 8, a conical housing 9, and an electrode assembly.

[0039] The support base 1 is fixed on the table of the EDM machine tool, and the electrode assembly is fixed on the spindle of the EDM machine tool;

[0040] The threaded bushing 3 is connected to the inclined plane thread of the support base 1, and the positioning plate 2 is coaxially fitted on the outside of the threaded bushing 3 and connected to the support base 1; the lower end face of the conical shell 9 is provided with a circular stop that matches the outer circle of the positioning plate 2, and the upper end face of the conical shell 9 is provided with a fixed stop; the pressure plate screw 5 is screwed into the internal thread of the threaded bushing 3 to fix the fastening pressure plate 4 at the fixed stop of the conical shell 9.

[0041] The support base 1 is symmetrically provided with L-shaped first support 6 and second support 8 on the left and right sides. The first support 6 and second support 8 are provided with through holes for the limiting shaft pin 7 to pass through. The limiting shaft pin 7 passes through the through hole and is embedded in the reserved hole of the conical shell 9.

[0042] The electrode assembly includes a clamping rod 11, an inner extension crossbar 12, a round bar electrode 13, and a set screw 14. The clamping rod 11 is connected to the inner extension crossbar 12 at a 90-degree angle, and the round bar electrode 13 passes through the inner extension crossbar 12 and is fixed by the set screw 14.

[0043] Furthermore, the conical shell 9 includes ribs 91, counterclockwise oblique dark holes 92, clockwise oblique dark holes 93, and connecting holes 94; the conical shell 9 is provided with three ribs 91 evenly distributed around the circumference, and each rib 91 is provided with one counterclockwise oblique dark hole 92, one clockwise oblique dark hole 93, and one connecting hole 94.

[0044] Furthermore, the counterclockwise oblique dark hole 92 and the clockwise oblique dark hole 93 are mirror symmetrical.

[0045] Furthermore, both the counterclockwise oblique dark hole 92 and the clockwise oblique dark hole 93 are connected to the connecting hole 94.

[0046] Furthermore, the through holes on the first support 6 and the second support 8 are coaxial, and their central axes intersect perpendicularly with the axis of the positioning disk 2.

[0047] Furthermore, the inclination angle of the inclined plane of the support base 1 The complementary angle is the angle between the counterclockwise oblique dark hole 92 and the clockwise oblique dark hole 93 and the neutral plane of the rib 91 passing through the axis of the shell.

[0048] Example 2, Reference Figure 1-6 This embodiment describes a method for using a fixture for clamping and positioning mirrored oblique holes in a housing rib during electrical discharge machining, specifically including the following steps:

[0049] S1. First, fix the support base 1 on the EDM machine table, align the left and right sides of the support base 1 so that they are parallel to the Y-axis of the machine tool; place the conical shell 9 on the positioning plate 2, adjust the angle of the conical shell 9 so that the rib 91 inside the conical shell 9 rotates to the radial positioning position of the first support 6, and the limiting pin 7 passes through the through hole on the first support 6 and inserts into the connecting hole 94 on the outside of the rib 91.

[0050] S2. Position the rib 91 at a horizontal position to the left of the X-axis of the machine tool. At this time, the axis of the counterclockwise oblique hole 92 on the rib 91 is rotated to the axis parallel to the horizontal Y-axis of the machine tool, which meets the positioning requirements for horizontal electrical discharge machining of oblique holes. Use the pressure plate 4 and pressure plate screw 5 to lock and fix the position of the conical shell 9 on the support base 1. At this time, the clamping and positioning preparation for electrical discharge machining of the counterclockwise oblique hole 92 on one rib 91 of the conical shell 9 is completed.

[0051] S3. Extend the round bar electrode 13 on the electrode assembly counterclockwise to the specified length, tighten it with the set screw 14, fix the clamping rod 11 of the electrode assembly on the machine tool spindle, and make the axis of the round bar electrode 13 parallel to the Y-axis of the machine tool. Start the machine tool spindle for trial feed, move the round bar electrode 13 to the center position of the counterclockwise oblique dark hole 92, visually align the round bar electrode 13 with the center of the counterclockwise oblique dark hole 92 reserved when casting the conical shell 9, and then perform formal electrical discharge machining on the counterclockwise oblique dark hole 92.

[0052] S4. The conical shell 9 has three ribs 91. Each rib 91 is provided with counterclockwise oblique dark holes 92 and clockwise oblique dark holes 93 in the same relative position. The three ribs 91 are sequentially positioned in the first support 6 by limiting shaft pins 7. The counterclockwise oblique dark holes 92 on the three ribs 91 are machined respectively.

[0053] S5. After all three counterclockwise oblique holes 92 have been machined, loosen the pressure plate screw 5, rotate the conical shell 9 along the positioning plate 2, and use the limiting shaft pin 7 to cooperate with the connecting hole 94 on the outside of the rib 91 so that the three ribs 91 are positioned in the second support 8 in sequence, and the clockwise oblique holes 93 on the three ribs 91 are machined in sequence.

[0054] S6. After the three sets of clockwise oblique dark holes 93 are processed, the round bar electrode 13 is removed, the pressure plate screw 5 is loosened and the pressure plate 4 is removed, and the conical shell 9 is taken off. At this time, the oblique dark hole EDM process of the three ribs 91 on the conical shell 9 is completed.

[0055] The left and right radial shaft pin positioning structure on the inclined surface of the support base in this invention can accurately achieve the horizontal rotation of the mirror-symmetrical oblique dark holes on the same rib of the shell to the required position, without relying on the consistency of the axial angles of the three ribs. Even if there are differences in the rib angles, reliable positioning can still be achieved. This effectively solves the core orientation problem in EDM where the axis of the oblique dark hole needs to be parallel to the X-axis or Y-axis of the machine tool. At the same time, the overall structure of this invention is simple, reducing the maintenance needs of complex components. The clamping and positioning are reliable and easy to adjust, effectively reducing the skill threshold and setup time for operators. It can stably ensure the machining accuracy and efficiency of the oblique dark holes, meeting the industrial batch machining needs of equipment conical shells.

[0056] This invention allows for the adaptation of oblique dark hole machining requirements in both clockwise and counterclockwise directions without altering the overall structure of the electrode assembly. This avoids the need for frequent replacement of electrode components adapted to different hole directions, reduces tooling adaptation costs, and improves the machining switching efficiency of oblique dark holes in different orientations. Simultaneously, the inner extension crossbar structure of the electrode assembly in this invention can drive the electrode to extend laterally to the target radial position of the oblique dark hole, successfully overcoming the "dead angle" limitation formed by the small end tapered opening of the housing. This solves the key problem that the electrode cannot reach the machining position when directly clamped on the spindle of the EDM machine, ensuring the spatial accessibility of EDM machining of oblique dark holes.

[0057] Although the invention has been described with reference to a limited number of embodiments, those skilled in the art will understand from the foregoing description that other embodiments are conceivable within the scope of the invention described herein. Furthermore, it should be noted that the language used in this specification has been chosen primarily for readability and instructional purposes, and not for the purpose of interpreting or limiting the subject matter of the invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the invention is illustrative and not restrictive, and the scope of the invention is defined by the appended claims.

Claims

1. A fixture for clamping and positioning mirrored oblique dark holes in shell ribs during electrical discharge machining, characterized in that, It includes a support base (1), a positioning plate (2), a threaded bushing (3), a pressure plate (4), a pressure plate screw (5), a first support (6), a limiting pin (7), a second support (8), a conical shell (9), and an electrode assembly; The support base (1) is fixed on the table of the EDM machine tool, and the electrode assembly is fixed on the spindle of the EDM machine tool; The threaded bushing (3) is connected to the inclined plane thread of the support base (1), and the positioning plate (2) is coaxially fitted on the outside of the threaded bushing (3) and connected to the support base (1); the lower end face of the conical shell (9) is provided with a circular stop that matches the outer circle of the positioning plate (2), and the upper end face of the conical shell (9) is provided with a fixed stop. The pressure plate screw (5) is screwed into the internal thread of the threaded bushing (3) to fix the fastening pressure plate (4) at the fixed stop of the conical shell (9); The support base (1) is symmetrically provided with L-shaped first support (6) and second support (8) on the left and right sides. The first support (6) and second support (8) are provided with through holes for the limiting pin (7) to pass through. The limiting pin (7) passes through the through hole and is embedded in the reserved hole of the conical shell (9). The electrode assembly includes a clamping rod (11), an inner crossbar (12), a round bar electrode (13), and a set screw (14). The clamping rod (11) is connected to the inner crossbar (12) at a 90-degree angle, and the round bar electrode (13) passes through the inner crossbar (12) and is fixed by the set screw (14).

2. The fixture for clamping and positioning mirrored oblique dark holes in shell ribs according to claim 1, characterized in that, The conical shell (9) includes ribs (91), counterclockwise oblique dark holes (92), clockwise oblique dark holes (93), and connecting holes (94); the conical shell (9) is provided with three ribs (91) evenly distributed around the circumference, and each rib (91) is provided with one counterclockwise oblique dark hole (92), one clockwise oblique dark hole (93), and one connecting hole (94).

3. The fixture for clamping and positioning mirrored oblique dark holes in a shell rib according to claim 2, characterized in that, The counterclockwise oblique dark hole (92) and the clockwise oblique dark hole (93) are mirror symmetrical.

4. The fixture for clamping and positioning mirrored oblique dark holes in a shell rib according to claim 3, characterized in that, Both the counterclockwise oblique dark hole (92) and the clockwise oblique dark hole (93) are connected to the connecting hole (94).

5. The fixture for clamping and positioning mirrored oblique dark holes in a shell rib according to claim 1, characterized in that, The through holes on the first support (6) and the second support (8) are coaxial, and their central axes intersect perpendicularly with the axis of the positioning disk (2).

6. The fixture for clamping and positioning mirrored oblique dark holes in a shell rib according to claim 2, characterized in that, The inclined plane of the support base (1) has an inclination angle The complementary angle is the angle between the counterclockwise oblique dark hole (92) and the clockwise oblique dark hole (93) and the rib (91) on the neutral plane passing through the shell axis.

7. The method of using the electrical discharge machining clamping and positioning fixture for mirrored oblique dark holes in shell ribs as described in claim 1, characterized in that, Specifically, the following steps are included: S1. First, fix the support base (1) on the table of the EDM machine tool, align the left and right sides of the support base (1) so that they are parallel to the "Y" axis of the machine tool; place the conical shell (9) on the positioning plate (2), adjust the angle of the conical shell (9) so that the rib (91) inside the conical shell (9) rotates to the radial positioning position of the first support (6), and the limiting pin (7) passes through the through hole on the first support (6) and inserts into the connecting hole (94) on the outside of the rib (91). S2. Position the rib (91) at a horizontal position to the left of the X-axis of the machine tool. At this time, the axis of the counterclockwise oblique hole (92) on the rib (91) is rotated to the axis parallel to the horizontal Y-axis of the machine tool, which satisfies the positioning requirements of the oblique hole for horizontal electrical discharge machining. Use the pressure plate (4) and pressure plate screw (5) to lock and fix the position of the conical shell (9) on the support base (1). At this time, the clamping and positioning preparation for electrical discharge machining of the counterclockwise oblique hole (92) on one rib (91) of the conical shell (9) is completed. S3. Extend the round bar electrode (13) on the electrode assembly counterclockwise to the specified length, tighten it with the set screw (14), fix the clamping rod (11) of the electrode assembly on the machine tool spindle, and make the axis of the round bar electrode (13) parallel to the Y axis of the machine tool. Start the machine tool spindle for trial feed, move the round bar electrode (13) to the center position of the counterclockwise oblique dark hole (92), and after visually aligning the round bar electrode (13) with the center of the counterclockwise oblique dark hole (92) reserved when casting the conical shell (9), perform formal electrical discharge machining of the counterclockwise oblique dark hole (92). S4. The conical shell (9) has three ribs (91) in total. Each rib (91) has a counterclockwise oblique hole (92) and a clockwise oblique hole (93) in the same relative position. The three ribs (91) are positioned in the first support (6) by the limiting shaft pin (7) in sequence, and the counterclockwise oblique holes (92) on the three ribs (91) are machined respectively. S5. After all three counterclockwise oblique dark holes (92) have been processed, loosen the pressure plate screw (5), rotate the conical shell (9) along the positioning plate (2), and use the limiting shaft pin (7) to cooperate with the connecting hole (94) on the outside of the rib (91) so that the three ribs (91) are positioned in the second support (8) in sequence, and process the clockwise oblique dark holes (93) on the three ribs (91) in sequence. S6. After the three sets of clockwise oblique dark holes (93) are processed, the round bar electrode (13) is removed, the pressure plate screw (5) is loosened and the pressure plate (4) is removed, and the conical shell (9) is taken off. At this time, the oblique dark hole EDM process of the three ribs (91) on the conical shell (9) is completed.

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