CN111872503A - A cross-scale electrical discharge machining device and method - Google Patents

Abstract

The invention relates to the technical field of electric discharge machining, and discloses a cross-scale electric discharge machining device and method. The invention includes a fixing plate fixedly connected with the working end of the electric discharge machining equipment, and the fixing plate is provided with a first guide wheel and a second guide wheel The electrode wire is wound around the wheel surface of the first guide wheel and the wheel surface of the second guide wheel, and a wire jacking frame is arranged in the middle of the guiding plate. The wire jacking frame can push the electrode wire away from the fixed plate to beyond the first The connection between the first guide wheel and the second guide wheel in the stretched state of the electrode wire, the top wire frame makes the electrode wire go beyond the wire in the stretched state of the electrode wire, and changes the supporting method of the electrode wire, thereby effectively suppressing the forced vibration of the electrode wire , which greatly improves the forming accuracy of electric discharge machining. The electrode wire keeps running during the machining process, which can make up for the electrode loss in time and maintain the machining accuracy. It is especially suitable for the machining of long channels across the scale. It has great promotion value and broad application prospects.

Description

A cross-scale electrical discharge machining device and method

technical field

The present invention relates to the technical field of electrical discharge machining, in particular to a cross-scale electrical discharge machining device and method.

Background technique

EDM refers to the method of machining the workpiece in a certain medium through the electro-erosion effect of the pulse discharge between the tool electrode and the workpiece electrode. EDM is a method of processing using electric and thermal energy that was studied in the 1940s and gradually applied to production. In the field of EDM technology, Wire EDM (WEDM) is the most concerned technology, which is widely used in mold manufacturing, machining of difficult-to-machine materials, and efficient, precise and micro-precision machining of three-dimensional complex surface parts.

The existing WEDM device is usually composed of a guide wheel, a tension wheel, a wire release drum, a wire take-up drum, a pulse power supply and other components. Two guide wheels are used to support the electrode wire. The workpiece is subjected to electric spark discharge to remove the workpiece. The electrode wire is supported at both ends. In theory, the shape of the electrode wire between the two guide wheels is a straight line. However, due to the low rigidity of the electrode wire, it is subject to discharge force, electromagnetic force, electrostatic force, fluid erosion and damping. The influence of the effect will produce flexural deformation and forced vibration. The actual motion trajectory is very complex, and from the direction of the electrode wire vibration, there are not only longitudinal vibrations along the axial direction of the electrode wire, but also perpendicular to the electrode wire. The transverse vibration on the axial plane, and the width of the workpiece slit mainly includes the diameter of the electrode wire, the distance of the discharge gap, and the transverse amplitude of the electrode wire. The amplitude of the transverse vibration of the electrode wire directly affects the machining accuracy of the wire cutting.

As the tool electrode of WEDM, the electrode wire directly participates in the spark discharge. The vibration of the electrode wire during the movement will inevitably lead to the decrease of the surface quality and machining accuracy of the WEDM process, and at the same time make the workpiece and the electrode wire. The spark discharge state is unstable, the retraction increases, and the processing efficiency decreases. In addition, the amplitude of the wire electrode is large in the middle and small at both ends, resulting in a waist drum-shaped processing effect. The greater the thickness of the cutting workpiece, the greater the span of the wire cutting wire, and the smaller the frequency of free vibration of the electrode wire, which is more easily affected by external vibration sources. Resonance occurs, the more obvious the vibration effect, the greater the vibration amplitude of the electrode wire, and the greater the dimensional deviation of the machining features.

Therefore, in the field of EDM technology, there is an urgent need for a method that can effectively suppress the vibration of the electrode wire by changing the supporting method of the electrode wire, so that the machining quality and forming accuracy of the wire EDM can be greatly improved, and it is especially suitable for machining cross-scale long channel microgrooves. The electric discharge machining device and method.

SUMMARY OF THE INVENTION

The invention overcomes the defects of the prior art, and provides a method that can effectively suppress the vibration of the electrode wire by changing the supporting mode of the electrode wire, so that the processing quality and forming accuracy of the wire electric discharge cutting are greatly improved, and it is especially suitable for processing cross-scale long channels. An electrical discharge machining apparatus and method for microgrooves.

The present invention is achieved through the following technical solutions:

A cross-scale electrical discharge machining device, comprising a fixed plate fixedly connected to the working end of the electrical discharge machining equipment, the fixed plate is provided with a first guide wheel and a second guide wheel, and the wheel surface of the first guide wheel is connected to the second guide wheel. An electrode wire is wound around the wheel surface of the guide wheel, and a wire jacking frame is arranged in the middle of the fixing plate. The connection of the electrode wire between the wheels in a straight state.

Further, the jacking wire frame includes a main support plate arranged in the middle of the jacking wire frame and extending away from the fixing plate, and the end of the extension end of the main support plate is provided with a guide groove for accommodating the electrode wire. The depth is less than the diameter of the electrode wire.

Further, both sides of the main support plate are respectively provided with a first side pull plate and a second side pull plate, the first side pull plate extends in a direction away from the fixed plate and also extends away from the support plate, the The second side pulling plate extends in a direction away from the fixing plate and in a direction away from the supporting plate. The end of the extending end of the first side pulling plate is provided with a first guide hole for the electrode wire to pass through. The end of the extension end of the pulling plate is provided with a second guide hole for the electrode wire to pass through.

Further, the first side pull plate and the second side pull plate are integrally formed or fixed with the main support plate to form a relatively fixed positional relationship.

Further, the first side pull plate and the second side pull plate are slidably connected to the main support plate respectively, and the overhang length of the first side pull plate and the second side pull plate can be controlled and adjusted.

Further, the first side pulling plate and the second side pulling plate are respectively inserted into the two sides of the main support plate facing the workpiece, and the insertion depth can be controlled and adjusted.

The present invention also provides an application of a cross-scale electrical discharge machining device, and the aforementioned cross-scale electrical discharge machining device is used to process a cross-scale long channel.

Further, the extension path of the cross-scale long channel is in a straight line, a curved arc or a turning shape.

The present invention also provides a cross-scale electrical discharge machining method utilizing the aforementioned cross-scale electrical discharge machining device, comprising the following steps:

A. Fix the workpiece on the operating table of the EDM equipment and make the surface to be machined of the workpiece face the jacking frame;

B. Select a suitable electrode wire according to the size of the channel and/or groove and/or cavity to be formed;

C. Lead the electrode wire out of the wire pay-off cylinder, bypass the first guide wheel, pass through the first guide hole and the second guide hole, bypass the second guide wheel, bypass the tensioning wheel, and introduce into the wire take-up cylinder;

D. Adjust the tension wheel to loosen the electrode wire, insert the part of the electrode wire between the first guide hole and the second guide hole into the guide groove, and adjust the tension wheel to tighten the electrode wire;

E. Turn on the electric discharge machining equipment, call the preset program, make the top wire frame move along the predetermined route, and at the same time the electrode wire runs, and the part of the electrode wire exposed in the guide groove is subjected to electro-erosion processing on the workpiece.

Compared with the prior art, the present invention has the following advantages and beneficial effects:

The invention includes a fixing plate fixedly connected with the working end of the electric discharge machining equipment, the fixing plate is provided with a first guide wheel and a second guide wheel, and electrode wires are wound around the wheel surface of the first guide wheel and the wheel surface of the second guide wheel , the middle of the guide plate is provided with a top wire frame, the top wire frame can push the electrode wire in the direction away from the fixed plate to beyond the connection line between the first guide wheel and the second guide wheel in the straight state of the electrode wire, and the top wire The frame makes the electrode wire go beyond the wire in the stretched state of the electrode wire, and changes the supporting method of the electrode wire, thereby effectively suppressing the forced vibration of the electrode wire. Short circuit, improve processing efficiency, and the width of the forming groove is closer to the diameter of the electrode wire, thereby greatly improving the forming accuracy of electrical discharge machining. , the groove width of the forming channel is not affected by the characteristic length, and is especially suitable for the processing of long channels across the scale, which has great promotion value and broad application prospects.

Description of drawings

The accompanying drawings described herein are used to provide further understanding of the embodiments of the present invention, and constitute a part of the present application, and do not constitute limitations to the embodiments of the present invention. In the attached image:

Fig. 1 is the three-dimensional schematic diagram of the overall structure of the present invention;

Fig. 2 is the macroscopic schematic diagram of the cross-scale long channel on the surface of the workpiece in the embodiment of the present invention;

3 is a schematic diagram of the end of the cross-scale long channel on the surface of the workpiece under a microscope in the embodiment of the present invention;

4 is a schematic diagram of the middle of the cross-scale long channel on the surface of the workpiece under a microscope in the embodiment of the present invention;

5 is a schematic diagram of the cross-scale long channel tail of the workpiece surface under a microscope in the embodiment of the present invention;

6 is a schematic diagram of a cross-scale long channel cross-section of a workpiece surface under a microscope in an embodiment of the present invention.

The marks in the attached drawings and the corresponding parts names:

1- Top wire rack, 2- The first side pull plate, 3- The first guide hole, 4- Electrode wire, 5- Guide groove, 6- The second guide hole, 7- The second side pull plate, 8- Main support plate, 9-fixed plate, 10-first guide wheel, 11-workpiece, 12-fastener, 13-second guide wheel.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and the accompanying drawings. as a limitation of the present invention.

A cross-scale electrical discharge machining device, comprising a fixed plate 9 fixedly connected to the working end of the electrical discharge machining equipment, the fixed plate 9 is provided with a first guide wheel 10 and a second guide wheel 13, and the wheel surface of the first guide wheel 10 is connected with the first guide wheel 10. Electrode wires 4 are wound around the surfaces of the two guide wheels 13 , and a wire jacking frame 1 is arranged in the middle of the fixing plate 9 through the fasteners 12 . The wire jacking frame 1 can push the electrode wire 4 away from the fixing plate 9 to the Exceeds the connection line between the first guide wheel 10 and the second guide wheel 13 in the straight state of the electrode wire 4 . With reference to the positions in FIG. 1 of the description, it can be understood that the electrode wire 4 can be located on the upper surface of the first guide wheel 10 and the upper surface of the second guide wheel 13 , or on the lower surface of the first guide wheel 10 and the lower surface of the second guide wheel 13, or the upper surface of the first guide wheel 10 and the lower surface of the second guide wheel 13, or the lower surface of the first guide wheel 10 and the second guide wheel 13 the upper wheel surface, and the electrode wire 4 exceeds the connection line of the electrode wire 4 between the first guide wheel 10 and the second guide wheel 13 in a straight state, that is, the electrode wire 4 between the two guide wheels passes through the top wire frame 1. The pushing action can exceed the position where the electrode wire 4 is in a straight state under the same winding method, so as to avoid the occurrence of the electrode wire 4 near the guide wheel on both sides and the workpiece 11 when the middle electrode wire 4 is performing EDM on the workpiece 11. unnecessary interactions. The top wire frame 1 makes the electrode wire 4 go beyond the connection of the straight state of the electrode wire 4, and changes the supporting mode of the electrode wire 4, thereby effectively suppressing the forced vibration of the electrode wire 4, and the vibration of the electrode wire 4 is well suppressed, so there are more Good dynamic stability will reduce short circuits and improve processing efficiency, and the width of the forming groove is closer to the diameter of the electrode wire 4, thereby greatly improving the forming accuracy of electric discharge machining. The electrode loss can be compensated in time to maintain the machining accuracy. In addition, the groove width of the forming channel is not affected by the characteristic length, which is especially suitable for the machining of long channels across scales.

Further, the jacking rack 1 includes a main support plate 8 arranged in the middle of the jacking rack 1 and extending in a direction away from the fixing plate 9. The end of the extension end of the main support plate 8 is provided with a guide groove 5 for accommodating the electrode wire 4. The guide groove The depth of 5 is smaller than the diameter of electrode wire 4 . It can be understood that when the extension length of the main support plate 8 is long, the first guide wheel 10 and the second guide wheel 13 on both sides are far away from the workpiece 11, and at this time, they can be used for electrical discharge machining without causing unnecessary mutual interaction. effect. The end of the extension end of the main support plate 8 is provided with a guide groove 5. The extension direction of the guide groove 5 is obviously parallel to the electrode wire 4, and the depth of the guide groove 5 is smaller than the diameter of the electrode wire 4 to ensure that a part of the electrode wire 4 is located in the electrode wire 4. Outside the guide groove 5 , the required electro-erosion processing can be performed between the workpiece 11 and the guide groove 5 .

Further, both sides of the main support plate 8 are respectively provided with a first side pull plate 2 and a second side pull plate 7, the first side pull plate 2 extends away from the fixed plate 9 and also extends away from the support plate. The two side pull plates 7 extend in the direction away from the fixing plate 9 and also in the direction away from the support plate. The end of the extended end of the first side pull plate 2 is provided with a first guide hole 3 for the electrode wire 4 to pass through. The end of the extension end of the pulling plate 7 is provided with a second guide hole 6 for the electrode wire 4 to pass through. It can be understood that when the extension length of the main support plate 8 is short, the first guide wheel 10 and the second guide wheel 13 on both sides are closer to the workpiece 11, so the first side pull plate 2 and the second side pull plate are added. plate 7, and let the electrode wire 4 pass through the first guide hole 3 and the second guide hole 6. When the electrode wire 4 is tightened, the main support plate 8 exerts a thrust on the electrode wire 4 away from the fixing plate 9. The first side pulling plate 2 and the second side pulling plate 7 exert a pulling force close to the fixing plate 9 on the electrode wire 4, so as to avoid unnecessary interaction between the electrode wire 4 and the workpiece 11, and can also more effectively suppress or even avoid the electrode wire 4. The forced vibration of the wire 4 ensures the machining accuracy and forming quality.

Further, the first side pull plate 2 and the second side pull plate 7 and the main support plate 8 are integrally formed or fixed to form a relatively fixed positional relationship. It can be understood that the first side pull plate 2, the main support plate 8, and the second side pull plate 7 form a relatively fixed positional relationship, have a stable structure and good strength, and are more suitable for mass processing.

Further, the first side pull plate 2 and the second side pull plate 7 are slidably connected to the main support plate 8 respectively, and the overhang length of the first side pull plate 2 and the second side pull plate 7 can be controlled and adjusted. Furthermore, the first side pull plate 2 and the second side pull plate 7 are respectively inserted into the two sides of the main support plate 8 facing the workpiece 11, and the insertion depth can be controlled and adjusted. It can be understood that the controllable length can not only be used to adjust the tightness and inclination as required, but also to adapt to the non-flat surface of the working surface. At the same time, the inclination angles of the side pull plates on both sides can be set to different states, so that the need for avoiding interference can be taken into account, and the electrode wire 4 can be prevented from being bent too much, thereby prolonging the service life of the consumables.

The present invention also provides an application of a cross-scale electrical discharge machining device, and the aforementioned cross-scale electrical discharge machining device is used to process a cross-scale long channel. Further, the extension path of the cross-scale long channel is in a straight line, a curved arc or a turning shape. It can be understood that the use of electrode wires 4 of different sizes and shapes can produce cross-scale micro-long through grooves with different cross-sectional shapes, and the wire jacking frame 1 can form a straight line, Long passages of various shapes such as curved or curved.

The present invention also provides a cross-scale electrical discharge machining method utilizing the aforementioned cross-scale electrical discharge machining device, comprising the following steps:

A. Fix the workpiece 11 on the operating table of the EDM equipment and make the surface to be machined of the workpiece 11 face the screw jack 1;

B. Select a suitable electrode wire 4 according to the size of the channel and/or groove and/or cavity to be formed;

C. Lead out the wire electrode 4 from the pay-off cylinder, bypass the first guide wheel 10, pass through the first guide hole 3 and the second guide hole 6, bypass the second guide wheel 13, bypass the tensioning wheel, and introduce the retractor spool;

D. Adjust the tension wheel to loosen the electrode wire 4, insert the electrode wire 4 between the first guide hole 3 and the second guide hole 6 into the guide groove 5, and adjust the tension wheel to tighten the electrode wire 4;

E. Turn on the electric discharge machining equipment, call the preset program, make the jacking frame 1 move along the predetermined route, and at the same time the electrode wire 4 runs, and the part of the electrode wire 4 exposed to the guide groove 5 is subjected to electric erosion processing on the workpiece 11.

According to the above-mentioned processing method, the following examples were carried out:

Using molybdenum wire with a diameter of 0.1 mm, four cross-scale elongated semicircular cross-section through grooves with a length of 70 mm and a cutting depth of 48 μm were cut on the copper block. Measure the machining features under an optical microscope, and select three sections of the upper end, middle and tail of the workpiece 11 to measure the groove width size - as shown in Figure 3, the end groove width size distribution is between 99.13 ~ 99.52μm, tolerance 0.39μm; as shown in Figure 4, the size distribution of the groove width in the middle is between 101.05 and 101.62μm, with a tolerance of 0.57μm; as shown in Figure 5, the size of the groove width at the tail end is distributed between 99.02 and 101.46μm, with a tolerance of 2.44μm; The overall distribution is between 99.02 and 101.62 μm, with a tolerance of 2.6 μm. As shown in Figure 6, the accuracy of the channel cross-sectional shape is observed from the end face, and the three-point circle fitting measurement shows that the machining features have excellent roundness. It is shown that the processing technology can better suppress the vibration of the electrode wire 4, the forming precision is high, and the processing feature width is not affected by the length, which can effectively solve the problem of difficult processing of cross-scale slender channels.

It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. any such actual relationship or sequence exists. Moreover, the terms "comprising", "comprising" or any other variation thereof are intended to encompass a non-exclusive inclusion such that a process, method, article or device that includes a list of elements includes not only those elements, but also includes not explicitly listed or other elements inherent to such a process, method, article or apparatus.

It is to be understood that the terms "portrait", "landscape", "top", "bottom", "front", "rear", "left", "right", "vertical", "horizontal", "top" , "bottom", "inside", "outside", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, only for the convenience of describing the present invention, rather than indicating or implying the indicated components or mechanisms It must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as a limitation of the present invention.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (9)

1. A cross-scale electrical discharge machining device, comprising a fixing plate fixedly connected with the action end of the electrical discharge machining equipment, characterized in that the fixing plate (9) is provided with a first guide wheel (10) and a second guide wheel ( 13), an electrode wire (4) is wound around the wheel surface of the first guide wheel (10) and the wheel surface of the second guide wheel (13), and a wire jacking frame (1) is arranged in the middle of the fixing plate (9). ), the wire ejector (1) can push the electrode wire (4) in the direction away from the fixing plate (9) beyond the electrode wire between the first guide wheel (10) and the second guide wheel (13) (4) Connection in a straight state. 2. A cross-scale electrical discharge machining device according to claim 1, characterized in that, the jacking rack (1) comprises a main screw which is arranged in the middle of the jacking rack (1) and extends in a direction away from the fixing plate (9). A support plate (8), the end of the extension end of the main support plate (8) is provided with a guide groove (5) for accommodating the electrode wire (4), and the depth of the guide groove (5) is smaller than that of the electrode wire (4). diameter. 3. A cross-scale electrical discharge machining device according to claim 2, characterized in that, a first side pull plate (2) and a second side pull plate (7) are respectively provided on both sides of the main support plate (8). ), the first side pull plate (2) extends in a direction away from the fixing plate (9) at the same time as it extends away from the support plate, and the second side pull plate (7) is in a direction away from the fixing plate (9) At the same time, the extension extends away from the support plate, the end of the extension end of the first side pull plate (2) is provided with a first guide hole (3) for the electrode wire (4) to pass through, and the second side pull plate (2) is provided with a first guide hole (3). (7) The end of the extension end is provided with a second guide hole (6) for the electrode wire (4) to pass through. 4. A cross-scale electrical discharge machining device according to claim 3, wherein the first side pull plate (2) and the second side pull plate (7) are integrally formed with the main support plate (8) or Fixed connection to form a relatively fixed positional relationship. 5 . The cross-scale electrical discharge machining device according to claim 3 , wherein the first side pull plate ( 2 ) and the second side pull plate ( 7 ) are respectively slidably connected to the main support plate ( 8 ). 6 . , the overhang lengths of the first side pulling plate (2) and the second side pulling plate (7) can be controlled and adjusted. 6 . The cross-scale electrical discharge machining device according to claim 5 , wherein the first side pull plate ( 2 ) and the second side pull plate ( 7 ) are respectively inserted into the main support plate ( 8 ). 7 . It faces both sides of the workpiece (11), and the insertion depth can be adjusted in a controlled manner. 7 . An application of a cross-scale electrical discharge machining device, characterized in that the cross-scale electrical discharge machining device according to any one of claims 1 to 6 is used to process a cross-scale long channel. 8 . 8 . The application of a cross-scale electrical discharge machining device according to claim 7 , wherein the extending path of the cross-scale long channel is in a straight line, an arc shape or a turning shape. 9 . 9 . A cross-scale electrical discharge machining method utilizing the cross-scale electrical discharge machining device according to any one of claims 3 to 6 , wherein the method comprises the following steps: 10 . A. Fix the workpiece (11) on the operating table of the electric discharge machining equipment and make the to-be-machined surface of the workpiece (11) face the jacking frame (1); B. Select a suitable electrode wire (4) according to the size of the channel and/or groove and/or cavity to be formed; C. Lead the electrode wire (4) out of the pay-off cylinder, bypass the first guide wheel (10), pass through the first guide hole (3) and the second guide hole (6), and bypass the second guide wheel (13) ), bypass the tensioner, and introduce the take-up reel; D. Adjust the tensioning wheel to loosen the electrode wire (4), insert the electrode wire (4) part between the first guide hole (3) and the second guide hole (6) into the guide groove (5), adjust the tension The wheel tightens the electrode wire (4); E. Turn on the electric discharge machining equipment, call the preset program, make the top wire rack (1) move along the predetermined route, and at the same time the electrode wire (4) runs, and the part of the electrode wire (4) exposed to the guide groove (5) is opposite to The workpiece (11) is subjected to electro-erosion machining.

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