Electrode device for electric spark machining

Abstract

The invention relates to an electrode device for electrical discharge machining, which comprises tungsten steel electrode bars, at least one tungsten steel bar is connected with an electrode block, the electrode block is connected with a connecting block, the connecting block is connected with an adapter, and the electrode block and the connecting block form a special-shaped structure. The electrode device has the advantages of being small in electrode loss, high in machining stability and capable of achieving rapid and accurate positioning.

Description

Technical Field

[0001] The invention relates to the field of electric spark small hole machining, and in particular to an electrode device for electric spark machining. Background Art

[0002] Electrospark machining is a special machining method that relies on the instantaneous high temperature generated during discharge to melt and vaporize local metal. It has the unique advantages of non-contact machining, no restrictions on material strength and hardness, and high machining accuracy. Therefore, it is increasingly widely used in high-efficiency precision machining and micro-machining of machining materials in industrial fields such as aerospace, transportation, and mold manufacturing. The discharge electrode is the main actuator of electrospark machining, which is equivalent to the tool of a cutting machine tool. Therefore, the quality of the machining electrode directly affects the accuracy and effect of electrospark machining. In the prior art, due to improper selection of electrode materials or improper fixing methods during electrospark machining, there is an obvious problem of electrode loss, which directly affects the efficiency and accuracy of electrospark machining. At the same time, in the field of high-precision machining such as aerospace, due to the special-shaped structure of the machined parts or the special requirements of machining, the machining path is narrow and the machining angle is complex. The electrode is usually a slender rod with poor rigidity, large deformation, and easy deviation. In the process of small hole machining, it is difficult to observe the machining part and the electrode position in some positions, which leads to easy machining deviation, which can seriously cause the workpiece to be scrapped, and the electrode is easy to break, which ultimately affects the finished product effect and benefit of electrospark machining. Therefore, improving electrode loss, enhancing electrode applicability, and improving processing stability and processing accuracy are issues that need to be addressed urgently. Summary of the invention

[0003] The purpose of the invention is to disclose an electrode device for electric spark machining with low electrode loss, high machining stability, and fast and accurate positioning, and the length of the machining electrode can be adjusted according to machining needs.

[0004] The technical solution to realize the present invention is:

[0005] An electrode device for electrospark machining includes a tungsten steel electrode rod 1, wherein at least one tungsten steel rod 1 is connected to an electrode block 2, the electrode block 2 is connected to a connecting block 3, the connecting block 3 is connected to an adapter 5, wherein the electrode block 2 and the connecting block 3 form a special-shaped structure.

[0006] The adapter 5 is connected to the quick-change reference plate 6 .

[0007] The special-shaped structure includes an L-shaped, a Z-shaped or a Z-shaped with multiple fold lines.

[0008] The electrode block 2 and the connecting block 3 can be relatively displaced in at least one direction.

[0009] One end of the connecting block 3 is placed in the groove of the adapter 5, and the lateral screw 4 is pressed to achieve fine adjustment of the connecting block 3 in the vertical direction.

[0010] At least one layer of copper wire 10 is wound around the end of the tungsten steel electrode rod 1 and is fitted with the mounting hole of the electrode block 2.

[0011] The electrode block 2 and the connecting block 3 are connected by a cylindrical pin and a screw, and fine adjustment in the vertical direction is achieved.

[0012] The electrode block 2 and the connecting block 3 are connected by a pin shaft.

[0013] The electrode block 2 and the connecting block 3 are rotatably connected, and there are accurate scale lines at appropriate positions on the electrode block 2 or the connecting block 3.

[0014] The tungsten steel rod 1 is one or more, and the multiple electrode rods are arranged at equal or unequal distances.

[0015] An electrode device for electric discharge machining provided by the technical solution of the present invention uses tungsten steel alloy as the material of the electrode rod. It has a high melting point and good electrical conductivity. The electrode deformation and loss are extremely small under high temperature conditions, and it is not easy to deform during the processing, reducing the number of electrode replacements. And through the clearance fit with the mounting hole of the electrode block 2 and using copper wire 10 for soldering, accurate positioning is achieved and it is conducive to the high-precision repeated replacement of the electrode rod; a connecting block 3 is installed at the lower part of the electrode block 2 to extend the vertical length of the electrode block 2, and by adjusting the shape and structure of the electrode block 2 and the connecting block 3, the machining area of the electrode is increased, and areas with concealed positions and complex angles can be machined; a quick-change reference piece 6 is installed at the lowermost end of the electrode device. By docking the quick-change reference piece with the machine tool reference surface, the quick positioning and assembly of the electrode device and the machine tool are realized, improving the machining accuracy and machining efficiency. Therefore, the electrode device for electric discharge machining provided by the technical solution of the present invention can improve electrode loss, enhance electrode applicability, improve machining stability and machining accuracy, and provide a high-quality and high-efficiency electrode machining device for the field of electric discharge fine machining. Description of the Drawings

[0016] Figure 1 It is a schematic diagram of the overall structure of the electrode device for electric discharge machining;

[0017] Figure 2 It is a schematic diagram of the structure of an electrode block of the electrode device for electric discharge machining;

[0018] Figure 3 It is a schematic diagram of another electrode block structure of the electrode device for electric discharge machining;

[0019] Figure 4 It is a schematic diagram of the overall structure of the electrode device for electric discharge machining from an inverted perspective;

[0020] Figure 5 It is a partial enlarged schematic diagram of the electrode rod and electrode block area of the electrode device for electric discharge machining;

[0021] Figure 6 Schematic diagram of the quick-change reference piece of the electrode device for electric discharge machining and its quick fixation to the machine tool;

[0022] Figure 7 Schematic diagram of the application of the electrode device for electric discharge machining. Specific embodiments

[0023] The specific embodiments of the present invention are given in detail below. It should be noted that the description of the specific embodiments of the present invention is for the purpose of facilitating a comprehensive understanding of the technical content of the present invention and should not be regarded as a limitation on the scope of protection of the claims of the present invention.

[0024] In the description of the present invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention.

[0025] The technical solution of the specific embodiment of the present invention is as follows:

[0026] An electrode device for electric discharge machining, including a tungsten steel electrode rod 1. At least one tungsten steel rod 1 is connected to an electrode block 2. The electrode block 2 is connected to a connection block 3. The connection block 3 is connected to a transfer seat 5. Among them, the electrode block 2 and the connection block 3 form a special-shaped structure.

[0027] As Figure 1As shown, the electrode device for electric discharge machining includes at least one tungsten steel electrode rod 1, an electrode block 2, a connecting block 3 and an adapter base 5. The tungsten steel electrode rod 1 is arranged at one end of the electrode block 2. An installation hole with a diameter equivalent to that of the electrode rod is provided at the upper end of the electrode block 2. The end of the electrode rod is inserted into the installation hole to be connected with the electrode block 2. The number of installation holes matches or is more than the number of electrode rods. The electrode rod is made of tungsten steel material, which has a high melting point and better electrode rigidity than other commonly used discharge materials (such as tungsten copper and graphite). During the electric discharge machining process, the loss is small, which can increase the service life of the electrode rod, reduce the frequency of replacing the electrode rod during the machining process, and is suitable for large-scale engineering applications. The electrode block 2 is arranged at the upper end of the connecting block 3. The bottom surface of the electrode block 2 is attached to and movably connected with the top surface of the connecting block 3. The adapter base 5 is arranged at the lower end of the connecting block 3. A groove is provided on the upper surface of the adapter base 5. The lower end of the connecting block 3 is inserted into the groove to be connected and fixed with the adapter base 5. Among them, after the connecting block and the electrode block are connected, a structure with a special-shaped structure in length is formed. The connecting block 3 is used to extend the electrode block 2, so that the electrode block 2 and the electrode rod can extend into a region with a complex path to approach the position to be machined.

[0028] The adapter base 5 is connected with a quick-change reference plate 6.

[0029] The electrode device for electric discharge machining further includes a quick-change reference plate 6. The quick-change reference plate 6 is arranged at the lower part of the adapter base 5 and is threadedly connected with the adapter base 5 through at least three screws (not shown in the figure). The bottom of the adapter base 5 is provided with holes corresponding to the screws. The quick-change reference plate 6 is provided with holes penetrating up and down corresponding to the screws. After the upper surface of the quick-change reference plate 6 is attached to the lower surface of the adapter base 5 and the hole positions are aligned, the screws are screwed into the adapter base 5 from the bottom of the quick-change reference plate 6 and tightened to fix the quick-change reference plate 6 at the bottom of the adapter base 5. At the same time, by adjusting the screws, the levelness of the electrode device for electric discharge machining is adjusted. Four grooves 11 are provided in four directions at the bottom of the quick-change reference plate 6, and the four grooves 11 are distributed in a cross shape. The quick-change reference plate 6 is connected with a pneumatic chuck 13 on the machine tool working platform through a floating bayonet device 12. The four grooves at the bottom are respectively engaged and connected with the carbide positioning posts 14 of the pneumatic chuck 13. The Z-direction reference plane 15 on the top surface and the X-direction and Y-direction reference planes on the side surfaces of the four positioning posts of the pneumatic chuck 13 are respectively attached to the surfaces in the grooves 11 on the quick-change reference plate 6, so that the quick-change reference plate 6 is matched and positioned with the reference plane of the machine tool, playing a role in connecting and fixing the electrode device and the machine tool. Through this quick-change reference plate 6, the electrode device can be quickly connected and fixed with the machine tool, facilitating the positioning and replacement of the electrode device. Particularly, four internal hexagonal screws are respectively arranged at the four corners of the quick-change reference plate 6, and four square grooves 11 are arranged at the bottom of the quick-change reference plate 6.

[0030] The special-shaped structure includes an L shape, a Z shape, or a Z shape with multiple broken lines.

[0031] The electrode block 2 is in a shape similar to an L shape or a Z shape, and the connecting block 3 is in the shape of a straight long rod. After the electrode block 2 and the connecting block 3 are connected, they form a special-shaped structure, specifically an L shape, a Z shape, or a Z shape with multiple broken lines. According to the position distribution and occlusion situation of the small holes to be processed, the shape after the connection of the electrode block 2 and the connecting block 3 is adjusted to facilitate electrode processing; in particular, the workpiece to be processed is the small holes of a multi-stage guide vane of an aeroengine. Since the multi-stage guide vane has two blade bodies in the front and the back, the area position of the small holes to be processed between the two blade bodies is hidden and there is occlusion. This area is defined as the occlusion area. The path into the occlusion area is narrow and the processing angle is complex. The special-shaped structure of the connecting block 3 and the electrode block 2 is designed as a Z shape. The electrode rod is horizontally inserted into the end of the electrode block 2, and the connecting block 3 is used to extend the electrode block 2 so that the electrode block 2 and the electrode rod 1 enter the occlusion area and approach the position of the small hole to be processed. The horizontally inserted electrode rod 1 is used to process the small holes arranged in the X axis direction. When processing the small holes arranged in the Z axis direction, the special-shaped structure of the connecting block 3 and the electrode block 2 is set as a Z shape with multiple broken lines, and the electrode rod 1 is longitudinally inserted into the electrode block 2 for processing.

[0032] The electrode block 2 and the connecting block 3 can be displaced relative to each other in at least one direction.

[0033] The bottom surface of the electrode block 2 is attached to the top surface of the connecting block 3. Based on this contact surface, the electrode block 2 and the connecting block 3 can move relative to each other in the horizontal direction, including moving forward and backward in the horizontal direction, or moving forward and backward in the horizontal direction, to adjust the connection and fixing position of the electrode block 2 and the connecting block 3.

[0034] One end of the connecting block 3 is placed in the groove of the adapter seat 5 and is pressed by the lateral screw 4 to achieve fine adjustment in the vertical direction of the connecting block 3.

[0035] The lower end of the connecting block 3 is inserted into the groove formed on the upper surface of the adapter base 5. At least one through hole is formed on one side surface of the adapter base 5. The lateral screw 4 is horizontally inserted into the through hole from the side surface of the adapter base 5 and presses the connecting block 3 located in the groove, so as to realize the connection and fixation of the connecting block 3 and the adapter base 5. The lower end of the connecting block 3 is inserted into the groove. The longitudinal depth of the lower end of the connecting block 3 can be finely adjusted according to different machining positions and different machining directions of the machined small holes. After the lower end of the connecting block 3 enters the groove, it does not contact the bottom surface of the groove. By tightening the lateral screw 4, the two sides of the lower end of the connecting block 3 are clamped with the other side surface of the groove to fix the connecting block, or the lower end of the connecting block 3 contacts and abuts against the bottom surface of the groove, and then the lateral screw 4 is tightened to fix the connecting block 3 and the adapter base 5. Particularly, the workpiece to be machined is a double-guide vane small hole. The lower end of the connecting block 3 is inserted into the groove of the adapter base 5 and abuts against the bottom surface of the adapter base 5, and then the connecting block 3 is pressed by the lateral screw 4 to stably fix the connecting block 3 and the adapter base 5. Preferably, two lateral screws 4 are provided to press the connecting block 3.

[0036] At least one layer of copper wire 10 is wound around the end of the tungsten steel electrode rod 1 and is matched with the mounting hole of the electrode block 2.

[0037] A mounting hole with the same diameter as the electrode rod 1 is formed at the end of the electrode block 2. The electrode rod 1 passes through the mounting hole and extends about 1-2 mm out of the electrode block 2. At least one layer of copper wire 10 with good conductivity is wound around the electrode rod 1, and then the copper wire 10 is fixed to the electrode rod 1 by soldering. Preferably, the electrode rod 1 extends 1.5 mm out of the electrode block 2 and two layers of copper wire 10 are wound. The copper wire 10 has good ductility and conductivity, does not occupy too much space when wound around the electrode rod 1 and is convenient for winding. Winding two layers can not only fix the electrode rod and the electrode block 2 but also enhance the conductivity of the electrode, and can avoid the problems of insecure winding with one layer, occupying space and wasting materials with multiple layers of winding. The diameter of the mounting hole is set to be the same as the diameter of the electrode rod 1, and the two form a clearance fit. The mounting hole on the electrode block 2 is a small hole of the electrode wire made by high-speed drilling with a high-precision five-axis engraving and milling machine. The hole diameter tolerance and position tolerance are both within 0.005 mm, and the tolerance of the tungsten steel electrode rod 1 is within 0.01 mm after repeated replacement. Therefore, the electrode rod 1 can be fixed in position when inserted into the mounting hole, and high-precision repeated positioning of the electrode rod can be realized.

[0038] The electrode block 2 and the connecting block 3 are connected by a cylindrical pin and a screw, and fine adjustment in the vertical direction is realized.

[0039] The bottom surface of the electrode block 2 is fitted with the top surface of the connection block 3. Three through holes are provided at the bottom corresponding to the bottom surface of the electrode block 2. The three through holes have different apertures and are arranged in a line along the projection direction of the arrangement direction of the mounting holes of the electrode block 2. Among the three through holes, the through holes at both ends are pin holes, which are connected with cylindrical pins 7 and 9. The through hole in the middle is a threaded hole, which is connected with a screw 8. The threaded hole in the middle is connected with the screw 8. By fine-tuning the position of the screw 8 and controlling the tightening force, the positional relationship between the connection block 3 and the electrode block 2 can be fine-tuned in the vertical direction, and the electrode block 2 and the connection block 3 can be fixed. The two cylindrical pins 7 and 9 are of different sizes, which are used to determine the installation direction of the electrode block 2 and the connection block 3 to prevent reverse installation, and to confirm the connection position of the electrode block 2 and the connection block 3 to prevent the electrode block 2 from moving left and right. Preferably, the screw 8 is a hexagonal screw, and the cylindrical pins 7 and 9 are Φ4*16 cylindrical pins and Φ5*16 cylindrical pins, respectively.

[0040] The electrode block 2 and the connecting block 3 are connected by a pin shaft. The electrode block 2 and the connecting block 3 are rotatably connected, and the appropriate position of the electrode block 2 or the connecting block 3 is accurately engraved.

[0041] This structure is not specifically shown in the figure, that is, the electrode block 2 and the connecting block 3 are connected by a pin shaft, so that the electrode block 2 can rotate around the pin shaft. When it rotates to a required angle, the electrode block 2 and the connecting block 3 are fixed by screws or fastening structures. This rotation can appropriately adjust the angle between the electrode block 2 and the connecting block 3, and in essence also adjusts the macro structure of the electrode block 2, so that the electrode rod can enter the special part of the part. Precise engraving can improve the accuracy and efficiency of adjustment.

[0042] The tungsten steel rod 1 is one or more, and the multiple electrode rods are arranged with equal or non-equal distances.

[0043] The tungsten steel electrode rod 1 is inserted into the mounting hole of the electrode block 2. The number of mounting holes is equal to or greater than the number of tungsten steel electrode rods 1. According to processing requirements, one tungsten steel electrode rod 1 can be installed on the electrode block 2, or multiple tungsten steel electrode rods 1 can be installed. The electrode rods are arranged in the mounting hole of the electrode block 2 at equal intervals, or at non-equal intervals. Preferably, according to the arrangement and distribution of small holes in the blade to be processed, multiple tungsten steel electrode rods 1 are arranged, the number of tungsten steel electrode rods 1 is the same as the number of small holes in a single row, and the electrode rods are inserted into the mounting holes of the electrode block 2 at equal intervals, and the spacing of the electrode rods is the same as the spacing between the small holes. When a small hole is processed separately on the processing blade, a tungsten steel electrode rod 1 is set and inserted into the electrode block 2 for small hole processing.

[0044] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention. However, these corresponding changes and deformations should fall within the protection scope of the appended claims of the present invention.

Claims

1. An electrode device for electric discharge machining, comprising a tungsten steel electrode rod (1), characterized in that The at least one tungsten carbide bar (1) is connected to the electrode block (2), the electrode block (2) is connected to the connection block (3), and the connection block (3) is connected to the adapter base (5). Among them, the electrode block (2) and the connection block (3) form a special-shaped structure.

2. The electrode device for electric discharge machining according to claim 1, characterized in that The adapter base (5) is connected to the quick-change reference piece (6).

3. The electrode device for electric discharge machining according to claim 1 or 2, characterized in that The special-shaped structure includes an L shape, a Z shape, or a multi-folded Z shape.

4. The electrode device for electric discharge machining according to claim 3, characterized in that The electrode block (2) and the connection block (3) can be displaced relative to each other in at least one direction.

5. The electrode device for electric discharge machining according to claim 4, characterized in that One end of the connection block (3) is placed in the groove of the adapter base (5) and is pressed by the lateral screw (4) to achieve fine adjustment of the connection block (3) in the vertical direction.

6. The electrode device for electric discharge machining according to claim 5, characterized in that The end of the tungsten carbide electrode bar (1) is wound with at least one layer of copper wire (10) and is fitted with the mounting hole of the electrode block (2).

7. The electrode device for electric discharge machining according to claim 6, characterized in that The electrode block (2) and the connection block (3) are connected by a cylindrical pin and a screw to achieve fine adjustment in the vertical direction.

8. The electrode device for electric discharge machining according to claim 6, characterized in that A pin shaft connection is provided between the electrode block (2) and the connection block (3).

9. The electrode device for electric discharge machining according to claim 7 or 8, characterized in that, The electrode block (2) and the connection block (3) can be rotatably connected, and there are precise scale lines at appropriate positions on the electrode block (2) or the connection block (3).

10. The electrode device for electric discharge machining according to claim 9, characterized in that The tungsten carbide bar (1) is one or more, and the multiple electrode bars are arranged at equal or unequal distances from each other.

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