Upper wire guide mechanism of automatic wire threading EDM wire cutting machine

Abstract

An upper wire guide mechanism of an automatic wire threading electric spark wire cutting machine includes a slender wire guide tube, characterized in that the upper part of the wire guide tube is in an upper positioning and mounting chuck, realizing the positioning, clamping, air guiding and wire pre-guiding functions of the upper part of the wire guide tube. An air guiding wire guiding channel is provided on the upper part of the wire guide tube, which assists the feeding of the electrode wire so that the electrode wire can be fed smoothly and reliably. A precise wire guide nozzle is provided on the lower part of the wire guide tube, and a bypass air guide channel is provided on the periphery of the precise wire guide hole. In addition, the present scheme designs a precise positioning clamping mechanism, in which the precise positioning hole cooperates with the outer cylindrical surface of the lower part of the wire guide tube, and can precisely position, automatically clamp and release the lower part of the wire guide tube. The wire guide tube can move axially in the precise positioning hole. The present scheme solves the feasibility and reliability of automatic wire threading of the upper wire guide mechanism under various workpiece threading conditions and the problem of precise guiding of the electrode wire.

Description

Technical Field

[0001] The present invention relates to the technical field of wire-cut electric discharge machining, and in particular to an upper wire guide mechanism of a CNC reciprocating wire electric discharge machine with automatic wire threading. The CNC reciprocating wire electric discharge machine is commonly known as a "medium wire machine", and the upper wire guide mechanism of the electrode wire of the machine is an important component of the automatic wire threading system of the wire electric discharge machine. Background Art

[0002] As a metal cutting processing equipment, CNC reciprocating wire EDM machine tools (abbreviated as: EDM wire cutting machine tools) are widely used in the processing of precision and complex parts in manufacturing industries such as molds, aerospace, automobiles, energy, precision instruments, medical equipment, and electronic products, and occupy an important position in industrial production. EDM wire cutting uses a continuously moving thin metal wire (called electrode wire) as an electrode to perform pulse spark discharge on the workpiece to erode metal and cut and shape. Wire threading is required before or during the online cutting process. At present, most EDM wire cutting machines can only use manual wire threading. Manual wire threading is highly professional and requires professional personnel to operate. In addition, the wire threading process is complicated, demanding, labor-intensive, and inefficient. To this end, in recent years, technicians in this field have been working hard to research and develop fully automatic wire threading devices and methods suitable for EDM wire cutting machines. Fully automatic wire threading is a complex and meticulous system engineering in the field of EDM wire cutting technology. It has high process requirements, many difficulties, and high technical difficulty. It has long been a technical problem in this field. Among them, how to realize automatic wire threading of the upper wire guide mechanism is one of the technical difficulties that need to be overcome.

[0003] On October 21, 2022, Chinese patent CN115213505A disclosed an invention patent application entitled "Guide mechanism for automatic wire threading of wire cutting machine tools". The invention discloses that "the wire guide tube is directly driven by a driving device to pass through the upper head and the workpiece and then aligned with the lower head, and the wire in the wire guide tube is directly sent into the lower head, which greatly improves the accuracy of wire feeding and effectively reduces the number of wire feeding failures". First of all, the invention discloses a wire guide mechanism for automatic wire threading of a slow-wire EDM wire cutting machine, which is different from the CNC reciprocating wire EDM wire cutting machine (commonly known as "medium wire cutting machine") of this application. There are many technical differences between the two, including the different electrode wire materials used by the two. The former uses copper wire, which is easy to straighten and not repeatedly used, and the latter uses molybdenum wire, which is difficult to straighten and needs to be repeatedly used. In addition, the automatic wire threading method and requirements are also different; secondly, the stability and reliability of the automatic wire threading of the invention and the positioning accuracy of the electrode wire are still insufficient. When the wire guide tube in the invention passes through the wire guide on the machine tool downward, the wire guide needs to be opened and the wire threading is completed. After the wire guide tube goes upward, the wire guide needs to be positioned and closed. Since the wire guide requires high precision, the closing precision is also required to be high when closing, and the precision requirement for the opening and closing mechanism is correspondingly high. The closing precision error of the wire guide will definitely affect the wire guiding precision. At the same time, the processed erosion will also adhere to the closing mechanism, which will definitely affect the closing precision and reliability of the wire guide. In addition, the opening and closing mechanism of the wire guide is relatively complex, and the manufacturing difficulty and cost are relatively high.

[0004] In view of this, the present invention proposes an upper wire guide mechanism suitable for automatic wire threading of an electric spark wire cutting machine tool, which is an effective way to solve this technical difficulty. Summary of the invention

[0005] The present invention provides an upper wire guiding mechanism for an automatic wire-threading electric spark wire cutting machine. The first purpose is to solve the problem of smooth automatic wire guiding of the molybdenum wire used in the electric spark wire cutting machine, which is bent and difficult to straighten and needs to be repeatedly used; the second purpose is to solve the problem of accurate positioning and reliability of the electrode wire by the wire guiding mechanism on the electric spark wire cutting machine; and the third purpose is to meet the automatic wire guiding needs of the machine tool in various wire threading scenarios.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: an upper wire guide mechanism of an automatic wire-threading electric spark wire cutting machine, the innovation of which lies in: including a wire guide tube, an upper positioning mounting chuck and a lower positioning clamping structure, and defining that the wire guide tube is composed of an upper part, a middle part and a lower part in a vertical state.

[0007] The wire guide tube is a slender tubular structure, with an axially penetrating wire guide hole in the middle. A first pre-wire guide structure is provided at the top of the upper part of the wire guide tube. The upper center of the first pre-wire guide structure is provided with a first wire guide taper hole that is larger at the top and smaller at the bottom, and the lower center is provided with a first pre-wire guide hole. The diameter of the first pre-wire guide hole is larger than the diameter of the electrode wire and smaller than the diameter of the wire guide hole. At the lower part of the first pre-wire guide hole, a group of jet holes are evenly spaced around the axis of the tube on the wire guide tube. In the assembled state, the first wire guide taper hole, the first pre-wire guide hole, and the wire guide hole are sequentially connected from top to bottom, and the three are coaxially arranged, wherein the first wire guide taper hole serves as the wire entry port for the wire guide tube.

[0008] The upper positioning mounting chuck is a positioning connection structure provided for the upper part of the wire guide tube, and the upper positioning mounting chuck includes a mounting seat, the electric spark wire cutting machine has a Z axis and a Z axis slide, and a W1 axis and a W1 axis slide that move parallel to the Z axis are provided on the Z axis slide, and the mounting seat is fixedly installed on the W1 axis slide, and a positioning mounting inner hole with an opening facing downward is provided on the mounting seat, and the axis of the positioning mounting inner hole is parallel to the W1 axis, and the upper part of the wire guide tube is fixedly installed in the positioning mounting inner hole in the assembled state. An air guide groove ring is provided between the upper outer edge of the wire guide tube and the positioning mounting inner hole around the tube axis direction, and the air guide groove ring constitutes an annular airway, and an air inlet hole is provided on the mounting seat, and one end of the air inlet hole leads to a compressed air source, and the other end is connected to the air guide groove ring, and one end of the group of jet holes is connected to the air guide groove ring, and the other end is connected to the wire guide hole on the wire guide tube, and the position of the connection point of all jet holes and the wire guide hole is lower than the position of the first pre-wire guide hole in the vertical direction.

[0009] The lower end of the wire guide tube is provided with a wire guide nozzle, and a precision wire guide hole for precisely guiding the electrode wire is provided in the center of the wire guide nozzle. The precision wire guide hole in the wire guide nozzle is coaxial with the outer cylinder at the lower part of the wire guide tube, and the precision wire guide hole is connected with the wire guide hole in the axial direction of the wire guide tube. The lower part of the wire guide tube is provided with an air outlet hole, and the air inlet hole, the air guide groove ring, a group of jet holes, the wire guide hole and the air outlet hole form an air guide channel from top to bottom.

[0010] The lower positioning clamping structure is a positioning clamping structure provided for the lower part of the wire guide tube, and a lower positioning hole is provided on the lower positioning clamping structure. The lower positioning hole is used to position the outer cylindrical surface of the lower part of the wire guide tube, and the positioning center axis of the lower outer cylindrical surface of the wire guide tube is coaxial with the axis of the positioning installation inner hole on the mounting seat. The lower positioning clamping structure can automatically lock or release the lower part of the wire guide tube in the lower positioning hole. In the released state, the wire guide tube can move up and down in the lower positioning hole along the axial direction, and the lower positioning clamping structure is fixedly mounted on the Z-axis slide.

[0011] The relevant contents in the above technical solution are explained as follows:

[0012] 1. In the above scheme, the wire-cut electric discharge machine tool is an index-controlled reciprocating wire-cut electric discharge machine tool, commonly known as a "medium wire-cut machine tool".

[0013] 2. In the above scheme, the "wire guide tube is a slender tubular structure" means that the wire guide tube is a tubular structure with a small diameter and a long length, with a diameter in the range of Φ1-Φ20mm, a length in the range of 100-1000mm, and an aspect ratio in the range of 5:1-500:1. Preferably, the diameter is in the range of Φ2-Φ8mm, the length is in the range of 100-1000mm, and the aspect ratio is in the range of 10:1-300:1.

[0014] 3. In the above scheme, the top of the upper part of the wire guide tube is provided with a first countersunk hole with an opening facing upward, and the first pre-wire guide piece is fixedly arranged in the first countersunk hole, the first wire guide taper hole is arranged at the upper center position of the first pre-wire guide piece, and the first pre-wire guide hole is arranged at the lower center open position of the first pre-wire guide piece.

[0015] 4. In the above scheme, the group of jet holes are arranged obliquely around the tube axis on the wire guide tube, the inclination angle between the jet hole axis and the tube axis is an acute angle, and the jet direction is obliquely downward.

[0016] 5. In the above scheme, a second countersunk hole with an opening facing downward is provided at the bottom end of the lower part of the wire guide tube, the wire guide nozzle is fixedly arranged in the second countersunk hole, a second pre-wire guide piece is arranged above the wire guide nozzle, and a third pre-wire guide piece is arranged below the wire guide nozzle, wherein the second pre-wire guide piece is located at the upper part of the second countersunk hole, a second wire guide taper hole with a larger upper part and a smaller lower part is opened at the upper center of the second pre-wire guide piece, and a second pre-wire guide hole is opened at the lower center. The wire guide nozzle is located in the middle of the second countersunk hole. The third pre-wire guide piece is located at the lower part of the second countersunk hole, a third pre-wire guide hole is opened at the upper center of the third pre-wire guide piece, and a third wire guide taper hole with a smaller upper part and a larger lower part is opened at the lower center. The diameters of the second pre-wire guide hole and the third pre-wire guide hole are both larger than the electrode wire diameter and smaller than the wire guide hole diameter, and the diameter of the precision wire guide hole is larger than the electrode wire diameter and smaller than the diameters of the second pre-wire guide hole and the third pre-wire guide hole. In the assembled state, the second wire guide taper hole, the second pre-wire guide hole, the precision wire guide hole, the third pre-wire guide hole, and the third wire guide taper hole are sequentially connected from top to bottom and are coaxially arranged, wherein the precision wire guide hole in the wire guide nozzle is coaxial with the lower outer cylinder of the wire guide tube, and the third wire guide taper hole serves as the wire threading and extension port of the wire guide tube.

[0017] 6. In the above scheme, connecting air path grooves are opened between the second countersunk hole opening downward and the upper end surface of the second pre-wire guide sheet, the circumferential side surface of the second pre-wire guide sheet, and between the upper end surface of the third pre-wire guide sheet and the third pre-wire guide hole, so as to form a bypass air guide channel around the precision wire guide hole of the wire guide nozzle to avoid the resistance of the precision wire guide hole.

[0018] 7. In the above scheme, an air guide ring is arranged between the wire guide nozzle and the third pre-wire guide piece, and a wire threading hole is opened in the center of the air guide ring. The wire threading hole allows the precision wire guide hole located above to be connected with the third pre-wire guide hole located below.

[0019] A group of first air guide grooves or first air guide channels are provided on the circumferential hole wall of the second countersunk hole with the opening facing downward or on the wire guide tube and between the corresponding second pre-wire guide sheet and the wire guide nozzle, and the group of first air guide grooves or first air guide channels are evenly spaced around the tube axis. A radial air guide groove connected to the first air guide groove or first air guide channel is provided radially at the bottom of the second countersunk hole. A group of second air guide grooves or second air guide channels are provided along the radial direction on the upper end surface of the air guide collar, and the group of second air guide grooves or second air guide channels are evenly spaced along the circumferential direction of the tube axis. One end of the first air guide groove or the first air guide channel is connected to the wire guide hole above the second pre-wire guide sheet via a radial air guide groove, and the other end is connected to one end of the second air guide groove or the second air guide channel, and the other end of the second air guide groove or the second air guide channel is connected to the wire threading hole of the air guide ring, thereby forming a bypass air guide channel around the precision wire guide hole of the wire guide nozzle to avoid the resistance of the precision wire guide hole.

[0020] 8. In the above scheme, a wire feeding mechanism is provided on the W1-axis slide, which is located above the wire guide tube and arranged opposite to the wire entry port of the wire guide tube. In the working state, the W1 axis drives the upper positioning mounting chuck and the wire guide tube as a whole to perform digital linear motion along the W1-axis direction through the W1-axis slide. The wire feeding mechanism can digitally feed the electrode wire into or out of the wire guide tube.

[0021] 9. In the above scheme, the lower positioning clamping structure includes a connecting plate, which is fixedly connected to the Z-axis slide plate through a verticality adjustment block that can adjust the verticality of the wire guide tube, so that the connecting plate can move digitally up and down with the Z-axis.

[0022] A positioning seat for positioning the lower part of the wire guide tube is fixedly arranged on the connecting plate for the wire guide tube, the positioning seat is provided with a lower positioning hole with a V-shaped positioning surface that cooperates with the outer cylindrical surface of the lower part of the wire guide tube, the positioning axis of the V-shaped positioning surface to the outer cylindrical surface of the lower part of the wire guide tube is coaxial with the axis of the positioning installation inner hole on the mounting seat, and an automatically controllable clamping mechanism is arranged on the connecting plate for the V-shaped positioning surface, and when the lower part of the wire guide tube extends into the V-shaped positioning surface, the lower part of the wire guide tube can be automatically clamped or released with the cooperation of the clamping mechanism.

[0023] 10. In the above scheme, the clamping mechanism includes a lever, a locking block, a push-pull rod and a cylinder. The lever is supported on a connecting plate, the locking block is positioned and installed at one end of the push-pull rod, the other end of the push-pull rod is movably connected to one end of the lever, and the cylinder acts on the other end of the lever.

[0024] 11. In the above scheme, the clamping mechanism includes a compression spring, which presses between the lever and the connecting plate and acts in the direction of releasing the lower part of the wire guide tube. When the cylinder extends outward to press the lever, the push-pull rod is driven by the lever to move in the positive direction along its own axis, and the locking pressure block is pushed to cooperate with the V-shaped positioning surface to clamp the lower part of the wire guide tube. When the cylinder retracts, under the action of the compression spring, the push-pull rod is driven along its own axis and pulls the locking pressure block to move in the opposite direction, and the locking pressure block cooperates with the V-shaped positioning surface to release the lower part of the wire guide tube.

[0025] 12. In the above solution, the lever is provided with an elongated slot at the movable connection with the push-pull rod, a pin is provided for the elongated slot, and the other end of the push-pull rod is inserted into the elongated slot through the pin. One end of the push-pull rod is connected to the locking block through a T-slot structure.

[0026] 13. In the above scheme, a working liquid nozzle is fixedly arranged at the bottom of the connecting plate at the center position of the positioning hole for the lower outer cylindrical surface of the wire guide tube. The working liquid nozzle consists of a tapered hole and a group of liquid spray holes. The tapered hole is coaxially arranged below the wire guide tube, and a group of liquid spray holes are evenly arranged on the conical surface of the tapered hole around the tube axis. An annular channel is arranged inside the connecting plate for a group of liquid spray holes, and the annular channel is connected to a group of liquid spray holes. A working liquid channel is arranged inside the connecting plate for the annular channel, one end of the working liquid channel is connected to the annular channel, and the other end is connected to the outside through a working liquid joint.

[0027] 14. In the above scheme, O-rings are respectively provided at the upper and lower parts of the annular airway, and the O-rings are arranged at the joint surface between the upper outer edge of the wire guide tube and the positioning installation inner hole. The upper and lower O-rings seal the annular airway.

[0028] 15. In the above scheme, the guide wire tube is composed of an upper guide wire body arranged at the upper part, an intermediate tube arranged at the middle part and a lower guide wire body arranged at the lower part, wherein:

[0029] The upper guide wire body is composed of a head and a tail. The head of the upper guide wire body extends into the positioning installation inner hole as the upper part of the guide wire tube and is fixedly connected to the positioning installation inner hole. The first countersunk hole, the air guide groove ring, and a group of jet holes are all arranged on the upper guide wire body. The tail of the upper guide wire body is fixedly connected to the upper end of the intermediate tube.

[0030] The lower wire guide body consists of a head and a tail, the head of the lower wire guide body serves as the lower part of the wire guide tube, the second countersunk hole, a group of first air guide grooves or first air guide channels are all arranged on the lower wire guide body, and the tail of the lower wire guide body is fixedly connected to the lower end of the intermediate tube.

[0031] 16. In the above scheme, after the head of the upper wire guide body as the upper part of the wire guide tube extends into the positioning installation inner hole, the upper wire guide body is locked in the positioning installation inner hole by a locking screw.

[0032] The innovative points and technical concepts of the present invention are as follows: In order to solve the problems of stability and reliability of automatic wire threading of the wire guide mechanism on the wire-cut EDM machine and accurate positioning of the electrode wire, the innovative points and technical concepts of the present invention are as follows:

[0033] 1. The present invention adopts a slender wire guide tube, and the outer diameter of the wire guide tube can be ≤6mm. It is suitable for automatic wire threading of small and large wire threading holes of workpieces, automatic wire threading outside the workpiece, and automatic wire threading of complex shapes on the upper part of the workpiece.

[0034] 2. A precise wire guide nozzle is fixedly arranged at the lower part of the wire guide tube of the present invention, and the precise wire guide hole in the wire guide nozzle is coaxial with the outer cylinder at the lower part of the wire guide tube.

[0035] 3. The upper part of the wire guide tube is positioned and clamped in the upper positioning and mounting chuck of the present invention, realizing the functions of positioning and clamping the upper part of the wire guide tube, guiding air, and pre-guiding the wire. The upper positioning and mounting chuck is fixedly mounted on the W1 axis carriage of the machine tool, and the W1 axis carriage can drive the upper positioning and mounting chuck and the wire guide tube to move axially.

[0036] 4. The upper part of the wire guide tube of the present invention is provided with a special gas-assisted jet wire guide channel. After the upper positioning mounting chuck is installed in the upper part of the wire guide tube, the compressed air can be introduced into the wire guide hole of the wire guide tube through the inclined jet hole (gas guide inclined hole) provided on the upper part. The compressed air can assist the electrode wire fed into the wire feeding mechanism of the machine tool, so that the electrode wire can be fed smoothly and reliably. The compressed air of the wire guide tube can also play a role in cleaning the inside of the wire guide hole to ensure that the wire guide hole is unobstructed. The small-diameter first pre-wire guide hole (with a smaller inner hole) provided on the upper part of the wire guide tube has a barrier effect on the upward gas introduced into the wire guide hole, guiding the gas to flow downward.

[0037] 5. The first air guide groove, the air guide ring and the second air guide groove are arranged at the lower part of the wire guide tube of the present invention to cleverly form a bypass air guide channel for the precision wire guide hole, so that the compressed air can bypass the precision wire guide hole in the wire guide nozzle, be introduced into the third pre-wire guide hole below the precision wire guide hole and be ejected from the wire guide hole at the lower end of the wire guide tube to guide the wire feeding.

[0038] 6. The present invention sets a lower positioning clamping structure for the lower part of the wire guide tube. The lower positioning clamping structure adopts a V-shaped positioning surface to cooperate with the outer cylindrical surface of the lower part of the wire guide tube, which can accurately position, automatically clamp and release the lower part of the wire guide tube. When the lower part of the wire guide tube retracts to the precise positioning surface, the outer cylinder of the lower part of the wire guide tube (i.e., the precise wire guide nozzle) can be precisely positioned and locked, so that the wire guide nozzle can accurately guide the electrode wire during processing. When the positioning clamping structure (locking mechanism) is opened, the wire guide tube can move out from the precise positioning surface along the axial direction, approach the upper surface of the workpiece threading hole or the upper surface of the lower wire guide nozzle of the machine tool, and align with the workpiece threading hole or the center threading hole of the lower wire guide nozzle.

[0039] Due to the application of the above scheme, the present invention has the following advantages and effects compared with the prior art:

[0040] 1. Since the present invention adopts a slender wire guide tube with a precision wire guide nozzle (i.e., wire guide nozzle) at the lower end, the wire guide tube is driven by the corresponding motion mechanism of the machine tool, so that under various workpiece conditions, the lower end surface of the wire guide tube can be digitized close to the upper surface of the wire threading hole of the workpiece or the upper surface of the wire guide nozzle under the machine tool, and cooperates with the wire feeding mechanism of the machine tool to smoothly and effectively realize automated digital wire feeding.

[0041] 2. Since the gas-assisted jet channel is arranged inside the wire guide tube of the present invention, and in particular, the bypass air guide channel is cleverly arranged at the lower part of the wire guide tube, during the automatic wire threading process, under the action of the machine tool wire feeding mechanism, the gas-assisted jet wire guiding makes the automatic wire feeding smoother and more reliable.

[0042] 3. Since the present invention has a precision wire guide nozzle (i.e., wire guide nozzle) fixedly arranged at the lower end of the wire guide tube and a precision lower positioning clamping structure arranged at the lower part of the machine tool shaft head, the lower part of the wire guide tube can be precisely positioned, automatically clamped and released, so that when the lower part of the wire guide tube retracts to the precision lower positioning clamping structure, the lower cylinder of the wire guide tube, i.e., the precision wire guide nozzle (i.e., wire guide nozzle), can be precisely positioned and automatically locked in the precision positioning mechanism, so that the wire guide nozzle can accurately guide the electrode wire during processing and perform effective high-precision cutting processing. When the lower positioning clamping structure of the wire guide tube is automatically opened, the wire guide tube is extended axially under the drive of the corresponding mechanism of the machine tool, close to the upper surface of the workpiece threading hole or the upper surface of the lower wire guide nozzle of the machine tool, so that the wire head of the electrode wire sent out can be close to and aligned with the threading hole of the workpiece or the threading hole in the center of the lower wire guide nozzle, and the feeding of the electrode wire is smoothly realized.

[0043] 4. The present invention can utilize the wire guide tube to introduce compressed air to clean the wire guide channel.

[0044] 5. The wire guide tube of the present invention can be divided into three sections: upper, middle and lower. The upper section is a clamping, air guide and sealing section, the middle section is a slender catheter section, and the lower section is a precision wire guide and air guide section. The upper section, the lower section and the middle section can be coaxially connected by threads or other methods. The advantages of this solution are: first, by replacing the lower wire guide section, it is convenient to replace precision wire guide nozzles (i.e. wire guide nozzles) of different specifications, or to replace new precision wire guide nozzles after the inner hole of the precision wire guide nozzle is worn. Second, after the three sections are disassembled, it is convenient to clean the various parts of the wire guide tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Attached Figure 1 This is a front view of the upper wire guide mechanism of an embodiment of the present invention;

[0046] Attached Figure 2 It is a left view of the upper wire guide mechanism of an embodiment of the present invention;

[0047] Attached Figure 3 for Figure 1 AA section view in;

[0048] Attached Figure 4 for Figure 2 BB section view in;

[0049] Attached Figure 5 for Figure 3 CC section view in;

[0050] Attached Figure 6 for Figure 4 The enlarged view of point D in the figure;

[0051] Attached Figure 7 It is a combined diagram of the upper guide wire body, the first pre-guide wire piece and the O-ring;

[0052] Attached Figure 8 for Figure 4 The enlarged view of point E in the figure;

[0053] Attached Fig. 9 for Figure 8 The enlarged view of F in the figure;

[0054] Attached Fig.10 It is a combined diagram of the lower wire guide body, the second pre-wire guide piece, the wire guide nozzle, the air guide ring and the third pre-wire guide piece;

[0055] Attached Fig.11 for Fig.10 GG section view in;

[0056] Attached Fig.12 It is a three-dimensional diagram of the gas guide ring;

[0057] Attached Fig.13 This is the front view of the gas guide ring;

[0058] Attached Fig.14 for Fig.13 HH cross-sectional view;

[0059] Attached Fig.15 It is a cross-sectional view of the middle tube of the wire guide tube;

[0060] Attached Fig.16 Schematic diagram of the first type of machine tool automatic wire feeding state;

[0061] Attached Fig.17 Schematic diagram of the second type of machine tool automatic wire feeding state;

[0062] Attached Fig.18 Schematic diagram of the third type of machine tool automatic wire feeding state;

[0063] Attached Fig.19 Schematic diagram of the fourth type of machine tool automatic wire feeding state;

[0064] Attached Fig. 20 Schematic diagram of the fifth type of machine tool's automatic wire guide status.

[0065] In the above figures: 1. Wire guide tube; 2. Wire guide hole; 3. First countersunk hole; 4. First pre-wire guide sheet; 5. First wire guide taper hole; 6. First pre-wire guide hole; 7. Mounting seat; 8. Positioning installation inner hole; 9. Air guide groove ring; 10. Jet hole; 11. Air inlet hole; 12. Second countersunk hole; 13. Second pre-wire guide sheet; 14. Wire guide nozzle; 15. Air guide ring; 16. Third pre-wire guide sheet; 17. Second wire guide taper hole; 18. Second pre-wire guide hole; 19. Precision wire guide hole; 20. Wire threading hole; 21. Third pre-wire guide hole; 22. Third wire guide taper hole; 23. First air guide groove; 24. Second air guide groove; 25. Connecting plate; 26. Positioning seat; 27. V-shaped positioning surface; 28. Lever; 29. ​​Locking block; 30. Push-pull rod; 31. Cylinder; 32. Compression spring; 33. Long groove; 34. Pin; 35. Working fluid nozzle; 36. Conical hole; 37. Spray hole; 38. Annular channel; 39. Working fluid channel; 40. O-ring; 41. Upper wire guide body; 42. Lower wire guide body; 43. Locking screw; 44. Z-axis slide; 45. W1-axis slide; 46. Wire feeding mechanism; 47. Verticality adjustment block; 48. Push rod; 49. Support block; 50. Support shaft; 51. Intermediate tube; 52. Lower wire guide nozzle; 53. Workpiece; 54. Electrode wire; 55. Wire threading hole; 56. Air pipe joint. DETAILED DESCRIPTION

[0066] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0067] Embodiment: An upper wire guide mechanism of an automatic wire threading CNC reciprocating wire EDM machine tool (commonly known as "medium wire machine tool").

[0068] like Figure 1-15 As shown, the upper wire guide mechanism includes a wire guide tube 1 (see Figure 1-4 ), an upper positioning mounting chuck and a lower positioning clamping structure. Definition: The wire guide tube 1 is composed of an upper part, a middle part and a lower part in a vertical state.

[0069] The wire guide tube 1 is a slender tubular structure, in the middle of which is provided an axially penetrating wire guide hole 2 (in this embodiment, Φ2mm), and the wire guide hole 2 is coaxially arranged with the outer cylinder of the wire guide tube 1. The "wire guide tube is a slender tubular structure" means that the wire guide tube is a tubular structure with a small diameter and a long length, and its diameter is in the range of Φ1-Φ20mm, the length is in the range of 100-1000mm, and the length-to-diameter ratio is in the range of 5:1-500:1. Preferably, the diameter is in the range of Φ2-Φ8mm, the length is in the range of 100-1000mm, and the length-to-diameter ratio is in the range of 10:1-300:1. The top of the upper part of the wire guide tube 1 is provided with a first countersunk hole 3 (see Figure 6-7 ), the first countersunk hole 3 is fixedly provided with a first pre-wire sheet 4 (see Figure 6-7 ), the upper center of the first pre-wire sheet 4 is provided with a first wire taper hole 5 which is larger at the top and smaller at the bottom, and the lower center is provided with a first pre-wire hole 6 (see Figure 6-7 ), the diameter of the first pre-wire hole 6 is larger than the diameter of the electrode wire and smaller than the diameter of the wire hole 2 (see Figure 7 ). In this embodiment, the diameter of the first pre-wire hole 6 is Φ0.5mm. The first wire taper hole 5 guides the head of the electrode wire that penetrates the wire guide tube 1, and the first pre-wire hole 6 pre-guides the penetrated electrode wire. In the assembled state, the first wire taper hole 5, the first pre-wire hole 6, and the wire hole 2 are sequentially connected from top to bottom, and the three are coaxially arranged and coaxially arranged with the outer cylinder of the wire guide tube 1, wherein the first wire taper hole 5 serves as the wire entry port of the wire guide tube 1 (see Figure 6 ).

[0070] The upper positioning mounting chuck is a positioning connection structure provided for the upper part of the wire guide tube 1, and the upper positioning mounting chuck includes a mounting seat 7 (see Figure 1-4 and Figure 6 ), the wire EDM machine tool has a Z axis and a Z axis carriage 44 (see Figure 1-4 ), a W1 axis and a W1 axis carriage 45 (see FIG. 4 ) are provided on the Z axis carriage 44 and move parallel to the Z axis. Figure 1-4 ), the mounting seat 7 is fixedly mounted on the W1 axis carriage 45, and the mounting seat 7 is provided with a positioning mounting inner hole 8 with an opening facing downward (see Figure 6 ), the axis of the positioning inner hole 8 is parallel to the W1 axis, and the upper part of the wire guide tube 1 is fixedly installed in the positioning inner hole 8 in the assembled state. An air guide groove ring 9 is arranged around the tube axis between the upper outer edge of the wire guide tube 1 and the positioning inner hole 8 (see Figure 6), the air guide groove ring 9 forms an annular airway, and a group of jet holes 10 are evenly spaced around the tube axis on the wire guide tube 1 at the lower part of the first pre-wire guide hole 6 (see Figure 6-7 In this embodiment, there are four air inlets 11 (see FIG. Figure 3 ), one end of the air inlet 11 leads to a compressed air source through an air pipe connector 56 (see Figure 2-3 ), the other end is connected to the air guide groove ring 9, a group of jet holes 10 are connected to the air guide groove ring 9 at one end, and the other end is connected to the wire guide hole 2 on the wire guide tube 1 (see Figure 7 ), a group of jet holes 10 are arranged obliquely around the tube axis on the wire guide tube 1, the inclination angle between the axis of the jet hole 10 and the tube axis is an acute angle (30° in this embodiment), and the jet direction is obliquely downward (see Figure 7 ), the positions of the places where all the jet holes 10 are connected to the guide wire hole 2 are lower than the position of the first pre-guide wire hole 6 in the vertical direction (see Figure 7 In this embodiment, the jet hole 10 and the guide wire hole 2 are at the same height, but the present invention is not limited to this).

[0071] O-type sealing rings 40 are respectively arranged at the upper and lower parts of the annular airway (see Figure 6-7 ), the O-ring 40 is arranged at the joint surface between the upper outer edge of the wire guide tube 1 and the positioning installation inner hole 8, and the O-rings 40 arranged up and down seal the annular airway.

[0072] The lower end of the wire guide tube 1 is provided with a second countersunk hole 12 (see Figure 9-10 ), the second counterbore 12 is fixedly provided with a second pre-wire sheet 13, a wire guide nozzle 14, an air guide ring 15 and a third pre-wire sheet 16 in order from top to bottom (see Figure 9-10 ), wherein the second pre-wire sheet 13 has a second wire taper hole 17 with a larger upper portion and a smaller lower portion at the center of the upper portion, and a second pre-wire hole 18 (see Figure 9-10 The center of the wire guide nozzle 14 is provided with a precision wire guide hole 19 (see Figure 9-10 The wire guide nozzle 14 is made of high-hardness wear-resistant material. The diameter of the precision wire guide hole 19 is slightly larger than the electrode wire by several microns, which plays a precise guiding role for the electrode wire during operation. The center of the air guide ring 15 is provided with a wire threading hole 20 (see Figure 9-10 , Figure 12-14 The third pre-wire hole 21 is formed at the upper center of the third pre-wire sheet 16, and a third wire taper hole 22 with a smaller top and a larger bottom is formed at the lower center (see Figure 9-10). The diameters of the second pre-wire hole 18 and the third pre-wire hole 21 are Φ0.5mm and are both larger than the electrode wire diameter and smaller than the wire hole 2 diameter (Φ2mm). The diameter of the precision wire hole 19 is larger than the electrode wire diameter and smaller than the diameters of the second pre-wire hole 18 and the third pre-wire hole 21. The diameter of the threading hole 20 is larger than the diameters of the second pre-wire hole 18 and the third pre-wire hole 21. In the assembled state, the second wire taper hole 17, the second pre-wire hole 18, the precision wire hole 19, the threading hole 20, the third pre-wire hole 21, and the third wire taper hole 22 are sequentially connected from top to bottom, and the six are coaxially arranged (see Figure 9-10 ), wherein the precision wire guide hole 19 in the wire guide nozzle 14 is coaxial with the outer cylinder at the lower part of the wire guide tube 1, and the third wire guide taper hole 22 serves as the wire threading extension port of the wire guide tube 1 (see Fig.10 ).

[0073] A group of first air guide grooves 23 are provided on the circumferential wall of the second counterbore 12 with the opening facing downward or on the wire guide tube 1 between the corresponding second pre-wire guide sheet 13 and the wire guide nozzle 14 (see Figure 9-11 ) (This embodiment is not limited to this, the first air guide groove 23 can also be changed to a first air guide channel provided on the wire guide tube 1, and the effect is the same), a group of first air guide grooves 23 are evenly spaced around the tube axis direction (see Fig.11 In this embodiment, there are four first air guide grooves 23, but the present invention is not limited thereto). A radial air guide groove connected to the first air guide groove 23 or the first air guide channel is opened in the bottom of the second counterbore 12 in the radial direction. A group of second air guide grooves 24 are opened in the radial direction on the upper end surface of the air guide ring 15 (see Figure 12-14 ) (This embodiment is not limited to this, the second air guide groove 24 can also be changed to a second air guide channel arranged in the radial direction of the air guide ring 15, and the effect is the same), a group of second air guide grooves 24 are evenly spaced along the circumferential direction of the tube axis (see Figure 12-14 One end of the first air guide groove 23 is connected to the wire guide hole 2 above the second pre-wire guide sheet 13 through the radial air guide groove, and the other end is connected to one end of the second air guide groove 24, and the other end of the second air guide groove 24 is connected to the wire threading hole 20 of the air guide ring 15, so as to form a bypass air guide channel around the precision wire guide hole 19 of the wire guide nozzle 14 to avoid the resistance of the precision wire guide hole 19 (see Fig.10 ).

[0074] The reason for setting the bypass air guiding channel is: since the wire guiding nozzle 14 is used as a precision wire guiding nozzle, the diameter of the precision wire guiding hole 19 in the center thereof is only a few microns larger than the diameter of the electrode wire. When the electrode wire passes through the precision wire guiding hole 19, the compressed air in the wire guiding tube 1 is blocked and difficult to pass through. Therefore, the above-mentioned bypass air guiding channel is designed at the lower part of the wire guiding tube 1. When the compressed air is ejected downward from the wire guiding hole 2 in the wire guiding tube 1, it can avoid the precision wire guiding hole 19 and be ejected from the third pre-wire guiding hole 21 through the bypass air guiding channel, thereby assisting the downward delivery of the electrode wire.

[0075] In this embodiment, in order to facilitate processing and manufacturing, the guide wire tube 1 is designed to be composed of an upper guide wire body 41 (see Figure 7 ), the intermediate pipe 51 (see Fig.15 ) and the lower guide wire body 42 (see Fig.10 ) (the present invention is not limited thereto, and can be realized by processing a tubular member, which can be understood by those skilled in the art), wherein:

[0076] The upper guide wire body 41 is composed of a head and a tail (see Figure 7 ), the head of the upper guide wire body 41 as the upper part of the guide wire tube 1 extends into the positioning installation inner hole 8 and is fixedly connected with the positioning installation inner hole 8 (see Figure 6 ), the first countersunk hole 3, the air guide groove ring 9, and a group of jet holes 10 are all arranged on the upper guide wire body 41 (see Figure 7 ), the tail of the upper guide wire body 41 is fixedly connected to the upper end of the intermediate tube 51 (see Figure 6 , this embodiment adopts threaded connection).

[0077] The lower guide wire body 42 is composed of a head and a tail (see Fig.10 ), the head of the lower guide wire body 42 serves as the lower part of the guide wire tube 1 (see Figure 9-10 ), the second countersunk hole 12 and a group of first air guide grooves 23 are arranged on the lower guide wire body 42 (see Figure 10-11 ), the tail of the lower guide wire body 42 is fixedly connected to the lower end of the intermediate tube 51 (see Figure 8 , this embodiment adopts threaded connection).

[0078] After the head of the upper wire guide body 41 as the upper part of the wire guide tube 1 extends into the positioning installation inner hole 8, the upper wire guide body 41 is locked in the positioning installation inner hole 8 by a locking screw 43 (see Figure 3 ).

[0079] In this embodiment, a wire feeding mechanism 46 (see FIG. Figure 1-2 and Figure 4), the wire feeding mechanism 46 is located above the wire guide tube 1 and is arranged opposite to the wire insertion opening of the wire guide tube 1 (see Figure 4 ), in the working state, the W1 axis drives the upper positioning mounting chuck (mounting seat 7) and the wire guide tube 1 as a whole to digitally move linearly along the W1 axis direction through the W1 axis drag plate 45, and the wire feeding mechanism 46 can digitally feed the electrode wire into or out of the wire guide tube 1.

[0080] The lower positioning and clamping structure is a positioning and clamping structure provided for the lower part of the wire guide tube 1, and the lower positioning and clamping structure includes a connecting plate 25 (see Figure 1 and Figure 3 ), the connecting plate 25 is fixedly connected to the Z-axis carriage 44 through a verticality adjustment block 47 which can adjust the verticality of the wire guide tube 1 (see Figure 1-4 ), so that the connecting plate 25 can move digitally up and down along the Z axis.

[0081] The connecting plate 25 is fixedly provided with a positioning seat 26 (see FIG. Figure 1-2 , Figure 3 and Figure 5 The positioning seat 26 is provided with a V-shaped positioning surface 27 (see Figure 5 ), the positioning axis of the V-shaped positioning surface 27 for the lower outer cylindrical surface of the guide wire tube 1 is coaxial with the axis of the positioning and mounting inner hole 8 on the mounting seat 7, and a clamping mechanism that can be automatically controlled is provided on the connecting plate 25 for the V-shaped positioning surface 27. When the lower part of the guide wire tube 1 extends into the V-shaped positioning surface 27, the lower part of the guide wire tube 1 can be automatically clamped or released with the cooperation of the clamping mechanism.

[0082] The clamping mechanism includes a lever 28, a locking block 29, a push-pull rod 30 and a cylinder 31 (see Figure 5 ), the lever 28 is supported on the connecting plate 25, the locking block 29 is positioned and installed at one end of the push-pull rod 30, and the other end of the push-pull rod 30 is movably connected to one end of the lever 28 (see Figure 8 ), the cylinder 31 acts on the other end of the lever 28 (see Figure 5 ).

[0083] The clamping mechanism includes a compression spring 32 (see Figure 5 ), the compression spring 32 presses between the lever 28 and the connecting plate 25, and acts in the direction of releasing the lower part of the wire guide tube 1. When the cylinder 31 extends outward to press the lever 28, the lever 28 drives the push-pull rod 30 to move forward along its own axial direction, and pushes the locking pressure block 29 to cooperate with the V-shaped positioning surface 27 to clamp the lower part of the wire guide tube 1. When the cylinder 31 retreats, under the action of the compression spring 32, the push-pull rod 30 is driven along its own axial direction and pulls the locking pressure block 29 to move in the opposite direction, and the locking pressure block 29 cooperates with the V-shaped positioning surface 27 to release the lower part of the wire guide tube 1 (see Figure 5). In the released state, the wire guide tube 1 can move up and down along the axial direction in the lower positioning hole.

[0084] The lever 28 is provided with an elongated slot 33 (see FIG. Figure 5 ), a pin 34 is provided for the elongated slot 33, and the other end of the push-pull rod 30 is inserted into the elongated slot 33 through the pin 34 (see Figure 5 One end of the push-pull rod 30 is connected to the locking block 29 via a T-slot structure (see Figure 8 ).

[0085] In this embodiment, the clamping mechanism is not limited to the lever mechanism described above, and may also be directly implemented by a cylinder, a solenoid valve, a cam mechanism, etc.

[0086] In this embodiment, in order to realize cooling of the processing area and removal of discharge erosion products, a working liquid nozzle 35 is fixedly arranged at the bottom of the connecting plate 25 for positioning the center position of the lower outer cylindrical surface of the wire guide tube 1 in accordance with the lower positioning hole (see Figure 8 ), the working liquid nozzle 35 is composed of a tapered hole 36 and a group of liquid spray holes 37 (see Fig. 9 ), the conical hole 36 is coaxially arranged below the wire guide tube 1, and a group of liquid injection holes 37 are evenly arranged on the conical surface of the conical hole 36 around the tube axis (see Fig. 9 An annular channel 38 is provided inside the connecting plate 25 for a group of liquid spraying holes 37 (see Figure 3 ), the annular channel 38 is connected to a group of liquid spray holes 37. A working liquid channel 39 is provided inside the connecting plate 25 for the annular channel 38 (see Figure 3 and Figure 5 ), one end of the working fluid channel 39 is connected to the annular channel 38, and the other end is connected to the outside through the working fluid joint. When the machine tool opens the working fluid, the working fluid is sprayed at a certain angle to the electrode wire on the upper surface of the workpiece through the spray hole 37, and the working fluid is brought into and out of the discharge machining area through the high-speed movement of the electrode wire, which plays a role in cooling the machining area and removing the discharge erosion products.

[0087] The specific application of the present invention in automatic wire threading of machine tools is introduced below:

[0088] The present invention adopts the lower end self-contained wire guide nozzle 14 (see Fig. 9 , precision wire guide nozzle) and can perform gas-assisted jet wire guiding, so when the machine tool is automatically threading the wire, the need for upper wire guiding can be met in a variety of states:

[0089] 1. Thread the upper wire through the small diameter pre-threading hole of the workpiece (the pre-threading hole of the workpiece is generally around Φ1mm).

[0090] like Fig.16As shown, in this state, the machine tool moves the wire threading hole 55 of the workpiece 53 to the wire threading position during operation. At this time, the precision wire threading hole of the wire guide nozzle, the workpiece wire threading hole, and the precision wire threading hole of the lower wire guide nozzle are on the same axis, and then the Z axis of the machine tool drives the wire guide tube 1 and the positioning seat 26 downward to the specified position, and then the clamping mechanism in the lower positioning clamping structure releases the wire guide tube 1, and the machine tool W1 axis drives the wire guide tube 1 downward, so that the lower end face of the wire guide tube 1 is close to the wire threading hole 55 of the workpiece 53, and then the wire is fed by the wire feeding mechanism through the gas-assisted jet, so that the electrode wire head passes through the precision wire threading hole of the wire guide nozzle, the workpiece wire threading hole and the precision wire threading hole of the lower wire guide nozzle. After completing the wire threading, the machine tool W1 axis drives the wire guide tube 1 upward, and the lower part of the wire guide tube 1 retreats to the V-shaped positioning surface 27 of the positioning seat 26, and then is clamped and locked in the positioning seat 26 by the clamping mechanism, and the machine tool can start cutting processing.

[0091] 2.Thread the wire through the large threading hole of the workpiece (the threading hole is larger than the outer diameter of the wire guide tube).

[0092] like Fig.17 As shown, in this state, the machine tool moves the threading hole 55 of the workpiece 53 to the threading position, and the slender wire guide tube 1 can pass through the larger threading hole 55 of the workpiece 53, so that the lower end face of the wire guide tube 1 is close to the upper end face of the lower wire guide nozzle 52 and is aligned with the threading hole on the lower wire guide nozzle 52, so as to achieve smooth threading. If the slender wire guide tube 1 is not adopted, the wire guide tube 1 cannot pass through the threading hole 55 of the workpiece 53, cannot approach the upper end face of the lower wire guide nozzle 52, and the electrode wire 54 is curved, and cannot normally pass through the large threading hole of the workpiece 53 to enter the precision threading hole of the lower wire guide nozzle 52.

[0093] 3.Thread the wire through the threading hole with a stepped hole on the workpiece.

[0094] like Fig.18 As shown, in this state, the machine tool moves the wire threading hole 55 of the workpiece 53 to the wire threading position, and the slender wire guide tube 1 can pass through the larger step hole of the workpiece 53, so that the lower end of the wire guide tube 1 is close to and aligned with the upper end surface of the smaller wire threading hole 55 at the lower part of the workpiece 53, and the wire threading is successfully realized. Otherwise, the wire threading is also difficult to complete.

[0095] 4.Thread the wire from the slope of the workpiece.

[0096] like Fig.19 As shown, in this state, the machine tool moves the wire threading hole 55 of the workpiece 53 to the wire threading position, and the lower end of the slender wire guide tube 1 can approach and align with the wire threading hole 55 on the slope of the workpiece 53, and the wire threading is successfully completed.

[0097] 5.Thread the wire from the outside of the workpiece.

[0098] like Fig. 20As shown, in this state, the slender wire guide tube 1 can descend from the outside of the workpiece 53, especially the outside of the workpiece 53 of great height, so that the lower end face of the wire guide tube 1 is close to the upper end face of the lower wire guide nozzle 52 and is aligned with the wire guide hole in the center of the lower wire guide nozzle 52, and the wire threading is successfully completed.

[0099] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. An upper wire guide mechanism for an automatic wire threading electric spark wire cutting machine, characterized in that: It comprises a wire guide tube (1), an upper positioning mounting chuck and a lower positioning clamping structure, and it is defined that the wire guide tube (1) is composed of an upper part, a middle part and a lower part in a vertical state; The wire guide tube (1) is a slender tubular structure, wherein an axially penetrating wire guide hole (2) is provided in the middle thereof; a first pre-wire guide structure is provided at the top end of the upper portion of the wire guide tube (1); a first wire guide taper hole (5) which is larger at the top and smaller at the bottom is provided at the upper center of the first pre-wire guide structure, and a first pre-wire guide hole (6) is provided at the lower center; the diameter of the first pre-wire guide hole (6) is larger than the diameter of the electrode wire and smaller than the diameter of the wire guide hole (2); below the first pre-wire guide hole (6), a group of jet holes (10) are evenly spaced around the tube axis on the wire guide tube (1); in the assembled state, the first wire guide taper hole (5), the first pre-wire guide hole (6), and the wire guide hole (2) are sequentially connected from top to bottom, and the three are coaxially arranged, wherein the first wire guide taper hole (5) serves as a wire threading entrance for the wire guide tube (1); The upper positioning mounting chuck is a positioning connection structure provided for the upper part of the wire guide tube (1), and the upper positioning mounting chuck comprises a mounting seat (7). The electric spark wire cutting machine tool has a Z axis and a Z axis slide plate (44), and a W1 axis and a W1 axis slide plate (45) that move parallel to the Z axis are provided on the Z axis slide plate (44). The mounting seat (7) is fixedly installed on the W1 axis slide plate (45), and a positioning mounting inner hole (8) with an opening facing downward is provided on the mounting seat (7). The axis of the positioning mounting inner hole (8) is parallel to the W1 axis. In the assembled state, the upper part of the wire guide tube (1) is fixedly installed on the positioning mounting inner hole hole (8); an air guide groove ring (9) is provided between the upper outer edge of the guide wire tube (1) and the positioning installation inner hole (8) around the tube axis direction, the air guide groove ring (9) forming an annular air passage, an air inlet hole (11) is provided on the mounting seat (7), one end of the air inlet hole (11) leads to a compressed air source, and the other end is connected to the air guide groove ring (9); one end of the group of jet holes (10) is connected to the air guide groove ring (9), and the other end is connected to the guide wire hole (2) on the guide wire tube (1), and the position of the connection point of all the jet holes (10) and the guide wire hole (2) is lower than the position of the first pre-guide wire hole (6) in the vertical direction; The lower end of the wire guide tube (1) is provided with a wire guide nozzle (14), the center of the wire guide nozzle (14) is provided with a precision wire guide hole (19) for precisely guiding the electrode wire, the precision wire guide hole (19) in the wire guide nozzle (14) is coaxial with the outer cylinder at the lower part of the wire guide tube (1), and the precision wire guide hole (19) is connected with the axial wire guide hole (2) of the wire guide tube (1); the lower part of the wire guide tube (1) is provided with an air outlet, and the air inlet hole (11), the air guide groove ring (9), a group of jet holes (10), the wire guide hole (2) and the air outlet form an air guide channel from top to bottom; The lower positioning clamping structure is a positioning clamping structure provided for the lower part of the wire guide tube (1). The lower positioning clamping structure is provided with a lower positioning hole, which is used to position the lower outer cylindrical surface of the wire guide tube (1). The positioning center axis of the lower outer cylindrical surface of the wire guide tube (1) is coaxial with the axis of the positioning mounting inner hole (8) on the mounting seat (7). The lower positioning clamping structure can automatically lock or release the lower part of the wire guide tube (1) in the lower positioning hole. In the released state, the wire guide tube (1) can move up and down in the lower positioning hole along the axial direction. The lower positioning clamping structure is fixedly mounted on the Z-axis carriage (44).

2. The upper wire guide mechanism according to claim 1, characterized in that: The top end of the upper portion of the wire guide tube (1) is provided with a first countersunk hole (3) with an opening facing upwards, a first pre-wire guide piece (4) is fixedly arranged in the first countersunk hole (3), the first wire guide taper hole (5) is arranged at the upper center position of the first pre-wire guide piece (4), and the first pre-wire guide hole (6) is arranged at the lower center position of the first pre-wire guide piece (4).

3. The upper wire guide mechanism according to claim 1, characterized in that: The group of jet holes (10) are arranged obliquely around the tube axis on the wire guide tube (1), the inclination angle between the axis of the jet hole (10) and the tube axis is an acute angle, and the jet direction is obliquely downward.

4. The upper wire guiding mechanism according to claim 2, characterized in that: A second countersunk hole (12) with an opening facing downward is provided at the bottom end of the lower part of the wire guide tube (1), the wire guide nozzle (14) is fixedly arranged in the second countersunk hole (12), a second pre-wire guide piece (13) is arranged above the wire guide nozzle (14), and a third pre-wire guide piece (16) is arranged below the wire guide nozzle (14), wherein the second pre-wire guide piece (13) is located at the upper part of the second countersunk hole (12), a second wire guide taper hole (17) with a larger upper part and a smaller lower part is opened at the upper center of the second pre-wire guide piece (13), and a second pre-wire guide hole (18) is opened at the lower center; the wire guide nozzle (14) is located in the middle part of the second countersunk hole (12); the third pre-wire guide piece (16) is located at the lower part of the second countersunk hole (12), a third pre-wire guide hole (21) is opened at the upper center of the third pre-wire guide piece (16), and a third pre-wire guide hole (22) is opened at the lower center; A third wire taper hole (22) is provided in the center, which is smaller at the top and larger at the bottom. The diameters of the second pre-wire hole (18) and the third pre-wire hole (21) are both larger than the diameter of the electrode wire and smaller than the diameter of the wire hole (2). The diameter of the precision wire hole (19) is larger than the diameter of the electrode wire and smaller than the diameters of the second pre-wire hole (18) and the third pre-wire hole (21). In the assembled state, the second wire taper hole (17), the second pre-wire hole (18), the precision wire hole (19), the third pre-wire hole (21), and the third wire taper hole (22) are sequentially connected from top to bottom and are coaxially arranged. The precision wire hole (19) in the wire guide nozzle (14) is coaxial with the lower outer cylinder of the wire guide tube (1), and the third wire taper hole (22) serves as a wire threading and extension port of the wire guide tube (1).

5. The upper wire guiding mechanism according to claim 4, characterized in that: A communicating air path groove is provided between the second countersunk hole (12) opening downward and the upper end surface of the second pre-wire guide piece (13), the circumferential side surface of the second pre-wire guide piece (13), and between the upper end surface of the third pre-wire guide piece (16) and the third pre-wire guide hole (21), thereby forming a bypass air guide channel around the precision wire guide hole (19) of the wire guide nozzle (14) to avoid the resistance of the precision wire guide hole (19).

6. The upper wire guiding mechanism according to claim 5, characterized in that: An air guide ring (15) is arranged between the wire guide nozzle (14) and the third pre-wire guide sheet (16), and a wire threading hole (20) is provided at the center of the air guide ring (15). The wire threading hole (20) vertically connects the precision wire guide hole (19) located above and the third pre-wire guide hole (21) located below; A group of first air guide grooves (23) or first air guide holes are provided on the circumferential hole wall of the second counterbore (12) with an opening facing downward or on the wire guide tube (1) between the corresponding second pre-wire guide sheet (13) and the wire guide nozzle (14), and the group of first air guide grooves (23) or first air guide holes are evenly spaced around the tube axis direction; a radial air guide groove connected to the first air guide groove (23) or the first air guide hole is provided in the radial direction at the bottom of the second counterbore (12); a group of second air guide grooves (24) or second air guide holes are provided in the radial direction on the upper end surface of the air guide collar (15), and a group of first air guide grooves (24) or second air guide holes are provided in the radial direction. The two air guide grooves (24) or the second air guide channels are evenly spaced in the circumferential direction of the tube axis; one end of the first air guide groove (23) or the first air guide channel is connected to the wire guide hole (2) above the second pre-wire guide sheet (13) via a radial air guide groove, and the other end is connected to one end of the second air guide groove (24) or the second air guide channel, and the other end of the second air guide groove (24) or the second air guide channel is connected to the wire threading hole (20) of the air guide ring (15), thereby forming a bypass air guide channel on the periphery of the precision wire guide hole (19) of the wire guide nozzle (14) to avoid the resistance of the precision wire guide hole (19).

7. The upper wire guiding mechanism according to claim 1, characterized in that: A wire feeding mechanism (46) is provided on the W1 axis drag plate (45), and the wire feeding mechanism (46) is located above the wire guide tube (1) and is arranged opposite to the wire insertion opening of the wire guide tube (1). In the working state, the W1 axis drives the upper positioning mounting chuck and the wire guide tube (1) as a whole to perform digital linear motion along the W1 axis direction through the W1 axis drag plate (45), and the wire feeding mechanism (46) can digitally feed the electrode wire into or out of the wire guide tube (1).

8. The upper wire guiding mechanism according to claim 1, characterized in that: The lower positioning clamping structure comprises a connecting plate (25), and the connecting plate (25) is fixedly connected to the Z-axis carriage (44) via a verticality adjustment block (47) capable of adjusting the verticality of the wire guide tube (1), so that the connecting plate (25) can digitally move up and down along with the Z-axis; A positioning seat (26) for positioning the lower part of the wire guide tube (1) is fixedly arranged on the connecting plate (25) for the wire guide tube (1). The positioning seat (26) is provided with a lower positioning hole having a V-shaped positioning surface (27) that cooperates with the outer cylindrical surface of the lower part of the wire guide tube (1). The positioning axis of the V-shaped positioning surface (27) for the outer cylindrical surface of the lower part of the wire guide tube (1) is coaxial with the axis of the positioning installation inner hole (8) on the installation seat (7). A clamping mechanism that can be automatically controlled is arranged on the connecting plate (25) for the V-shaped positioning surface (27). When the lower part of the wire guide tube (1) extends into the V-shaped positioning surface (27), the lower part of the wire guide tube (1) can be automatically clamped or released under the cooperation of the clamping mechanism.

9. The upper wire guiding mechanism according to claim 8, characterized in that: The clamping mechanism comprises a lever (28), a locking pressure block (29), a push-pull rod (30) and a cylinder (31); the lever (28) is supported on the connecting plate (25) in a swinging manner; the locking pressure block (29) is positioned and mounted on one end of the push-pull rod (30); the other end of the push-pull rod (30) is movably connected to one end of the lever (28); and the cylinder (31) acts on the other end of the lever (28).

10. The upper wire guiding mechanism according to claim 9, characterized in that: The clamping mechanism includes a compression spring (32), which presses between the lever (28) and the connecting plate (25) and acts in the direction of releasing the lower part of the wire guide tube (1). When the cylinder (31) extends outward to press the lever (28), the push-pull rod (30) is driven by the lever (28) to move in the positive direction along its own axis and push the locking pressure block (29) to cooperate with the V-shaped positioning surface (27) to clamp the lower part of the wire guide tube (1). When the cylinder (31) retreats, under the action of the compression spring (32), the push-pull rod (30) is driven along its own axis and pulls the locking pressure block (29) to move in the reverse direction, and the locking pressure block (29) cooperates with the V-shaped positioning surface (27) to release the lower part of the wire guide tube (1).

11. The upper wire guiding mechanism according to claim 9, characterized in that: The lever (28) is provided with an elongated slot (33) at a movable connection with the push-pull rod (30), and a pin (34) is provided for the elongated slot (33). The other end of the push-pull rod (30) is inserted into the elongated slot (33) via the pin (34); one end of the push-pull rod (30) is connected to the locking pressure block (29) via a T-slot structure.

12. The upper wire guiding mechanism according to claim 8, characterized in that: A working liquid nozzle (35) is fixedly arranged at the bottom of the connecting plate (25) at the center position of the lower outer cylindrical surface of the wire guide tube (1) in correspondence with the lower positioning hole. The working liquid nozzle (35) consists of a tapered hole (36) and a group of liquid spray holes (37). The tapered hole (36) is coaxially arranged below the wire guide tube (1), and the group of liquid spray holes (37) are evenly arranged on the tapered surface of the tapered hole (36) around the tube axis. An annular channel (38) is arranged inside the connecting plate (25) in correspondence with the group of liquid spray holes (37), and the annular channel (38) is connected to the group of liquid spray holes (37). A working liquid channel (39) is arranged inside the connecting plate (25) in correspondence with the annular channel (38), and one end of the working liquid channel (39) is connected to the annular channel (38), and the other end is connected to the outside through a working liquid joint.

13. The upper wire guiding mechanism according to claim 1, characterized in that: O-type sealing rings (40) are respectively arranged at the upper and lower parts of the annular airway. The O-type sealing ring (40) is arranged at the joint surface between the upper outer edge of the wire guide tube (1) and the positioning installation inner hole (8). The upper and lower O-type sealing rings (40) seal the annular airway.

14. The upper wire guiding mechanism according to claim 4, characterized in that: The wire guide tube (1) is composed of an upper wire guide body (41) arranged at the upper part, an intermediate tube (51) arranged at the middle part, and a lower wire guide body (42) arranged at the lower part, wherein: The upper wire guide body (41) is composed of a head and a tail. The head of the upper wire guide body (41) serves as the upper part of the wire guide tube (1) and extends into the positioning installation inner hole (8) and is fixedly connected to the positioning installation inner hole (8). The first countersunk hole (3), the air guide groove ring (9), and a group of jet holes (10) are all arranged on the upper wire guide body (41). The tail of the upper wire guide body (41) is fixedly connected to the upper end of the intermediate tube (51). The lower wire guide body (42) is composed of a head and a tail, the head of the lower wire guide body (42) serves as the lower part of the wire guide tube (1), the second countersunk hole (12), a group of first air guide grooves (23) or first air guide channels are arranged on the lower wire guide body (42), and the tail of the lower wire guide body (42) is fixedly connected to the lower end of the intermediate tube (51).

15. The upper wire guiding mechanism according to claim 14, characterized in that: After the head of the upper wire guide body (41) as the upper part of the wire guide tube (1) extends into the positioning installation inner hole (8), the upper wire guide body (41) is locked in the positioning installation inner hole (8) by means of a locking screw (43).

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