A variable gap electrolytic electric spark combined cutting processing method and device

Abstract

The invention discloses a variable-gap electrolytic-electric spark combined cutting processing method and device, comprising the following processing processes: process one: driving a servo control system to change the processing gap between an electrode wire and a workpiece into a spark discharge gap, and performing electric spark cutting according to a preset cutting trajectory; process two: driving a servo control system to change the processing gap between an electrode wire and a workpiece into a strong electrolytic processing gap, and performing strong electrolytic cutting according to a preset cutting trajectory; process three: driving a servo control system to change the processing gap between an electrode wire and a workpiece into a weak electrolytic processing gap, and performing weak electrolytic cutting according to a preset cutting trajectory; process four: driving a servo control system to change the processing gap between an electrode wire and a workpiece into an electrolytic polishing processing gap, and performing electrolytic polishing according to a preset cutting trajectory. The invention has the advantages of being able to completely remove defects such as waist bulge, heat-affected zone, and recast layer of workpieces with large thickness and large aspect ratio, and having high processing efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of electric spark cutting, in particular to a variable gap electrolytic electric spark combined cutting method and device. Background Art

[0002] In the fields of aerospace, nuclear industry, military industry, shipbuilding, etc., in order to ensure the strength, reliability and safety of certain large parts, the application scenarios of large integral components made of difficult-to-process materials such as high strength and high hardness are gradually increasing. These components usually have characteristics such as large thickness, narrow gaps (grooves), thin walls, large depth-to-diameter ratios or complex contours, making it difficult for conventional traditional processing technologies to meet their processing requirements or difficult to process. Wire EDM processing technology is currently a better solution.

[0003] Due to the principle and characteristics of wire EDM, the high temperature generated by spark discharge during the machining process causes the material to be instantly vaporized or melted. The material that cannot be discharged from the machining area in time reacts with the working medium to form a solidified product. If it cannot be removed from the machining position in time, a recast layer will be formed on the machining surface. The bonding strength between the recast layer and the substrate is not high, and there are defects such as microcracks and micropores on its surface, which will seriously affect the fatigue strength of the workpiece, seriously reducing the service life of the workpiece and product safety.

[0004] For workpieces with strict application scenarios and working conditions, such as large thickness, large aspect ratio, high precision, high surface quality, and form and position tolerance, medium-speed and slow-speed wire cutting processing technologies are currently widely used for processing. However, in the actual processing process, the processed surface is usually trimmed multiple times on the basis of the main cut to achieve the requirements of indicators such as accuracy, roughness, and form and position tolerance, while reducing the thickness of the recast layer. However, even if the slow-speed wire cutting process uses multiple trimming after the main cut, the recast layer cannot be eliminated, especially for workpieces with large thickness and large aspect ratio. The recast layer cannot be trimmed and removed, and there are processing defects such as waist drum. With the application restrictions on parts that produce recast layers on hot-processed surfaces such as EDM, laser processing, and ion beam processing in the aerospace field, new technical means are urgently needed to be developed.

[0005] The reasons why the workpiece will have a bulge after multiple EDM cutting are generally as follows: (1) When cutting thick and large depth-to-diameter workpieces, the cutting seam is narrow and long, and the middle part of the workpiece lacks electrolyte, resulting in poor flushing effect, so that the erosion products cannot be cleaned in time, and thus accumulate in this part, affecting the discharge machining process and the material etching efficiency. As a result, the actual size of the two ends of the processed workpiece is smaller, and the actual size of the middle part is larger, causing bulges, such as Figure 1As shown in the figure; (2) During the EDM multiple cutting process, except for the main cutting, the subsequent trimming is single-sided processing. The discharge explosion force from one side of the workpiece cannot be offset. Under the action of the discharge explosion force, the electrode wire will deviate away from the workpiece, and eventually the entire electrode wire will have a certain deflection during the processing stroke, resulting in a more obvious waist drum on the workpiece surface after multiple cutting;

[0006] Patent publication number CN112372098B discloses a straight-grain component wire electrospark cutting device and method, which specifically discloses using a controlled electrode wire to perform multiple electric spark trimming of a workpiece to achieve thinning or elimination of the recast layer. However, if a waist drum is generated on the workpiece surface after electric spark cutting, the middle section of the workpiece and the electrode wire are still processed by electric spark cutting. After multiple electric spark electrolytic machining, the waist drum will be more obvious, and the recast layer will not be able to be completely eliminated. Patent publication number CN118720301B discloses a return-type electrospark electrolytic combined processing method and device for straight-grained surface components, and specifically discloses that the use of return-type electrolytic cutting to remove the recast layer can achieve good results. However, for workpieces with large thickness and large aspect ratio, it is difficult to completely remove defects such as the recast layer, drum degree, heat-affected zone, etc. on the cutting surface through only one return processing. Therefore, it is impossible to completely remove the recast layer, drum degree, heat-affected zone, and recast layer defects of workpieces with large thickness and large aspect ratio; the processing efficiency of workpieces with large thickness and large aspect ratio that have high requirements on dimensional accuracy, surface roughness, and form and position tolerances and do not need a recast layer is low, the electrolytic electrospark combined cutting processing equipment is structurally auxiliary, inconvenient to operate, and has low processing flexibility. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the existing defects and provide a variable gap electrolytic spark combined cutting processing method and device. After the electrode wire performs the main electrospark cutting on the workpiece according to the preset cutting trajectory, the surface of the workpiece after the main electrospark cutting is sequentially subjected to strong electrolytic cutting, weak electrolytic cutting and electrolytic polishing by repeatedly changing the processing gap between the electrode wire and the workpiece, so that the waist drum degree, heat affected zone and recast layer defects of the workpiece with large thickness and large depth-to-diameter ratio can be completely removed; the processing procedures are reasonably arranged and the processing efficiency is high; the electrolyte sprayed by the auxiliary liquid injection system flows from top to bottom along the electrode wire, so that the flow renewal of the electrolyte in the processing gap and the removal of the electrolytic products are realized, and the strong electrolytic cutting efficiency, the weak electrolytic cutting efficiency, the electrolytic polishing efficiency and the finishing accuracy are improved; the main electrospark cutting stage, the electrolytic cutting rough processing stage, the electrolytic cutting fine processing stage and the electrolytic polishing super finishing stage can be selected, and the variable gap electrolytic spark combined cutting processing equipment has a simple structure, is easy to operate and has a high processing flexibility; and can effectively solve the problems in the background technology.

[0008] To achieve the above object, the present invention provides the following technical solution: a variable gap electrolytic spark combined cutting method, the method comprising a unidirectional wire feeding mechanism for driving an electrode wire to feed unidirectional wire on a numerically controlled machine tool, a tensioning mechanism for tensioning the electrode wire on the unidirectional wire feeding mechanism, and the following processing steps:

[0009] Before the cutting process begins, the workpiece is fixed in the electrolytic cell and immersed in the electrolyte. The positive and negative electrodes of the power supply are electrically connected to the workpiece and the electrode wire respectively. The negative electrode of the power supply is also electrically connected to an oscilloscope, and the power supply is turned on. After the electrode wire is tensioned by the tensioning mechanism, it is driven by the one-way wire feeding mechanism to feed the wire in one direction from top to bottom.

[0010] Process 1: EDM main cutting stage; in this stage, the parameters of the power supply are adjusted to the EDM wire cutting processing parameters; the servo control system is driven to change the processing gap between the electrode wire and the workpiece into the spark discharge gap L1, and when the signal of the oscilloscope in the servo control system and the software status in the control panel change from the no-load state to the spark discharge state, the EDM cutting is performed according to the cutting trajectory preset in the servo control system until the EDM main cutting of the workpiece is completed;

[0011] Process 2: electrolytic cutting rough machining stage; in this stage, the parameters of the power supply are adjusted to the strong electrolytic cutting machining parameters; the servo control system is driven to change the machining gap between the electrode wire and the workpiece into the strong electrolytic machining gap L2, and when the signal of the oscilloscope in the servo control system and the software status in the control panel show the strong electrolytic machining state, the strong electrolytic cutting is performed according to the cutting trajectory preset in the servo control system until the waist drum and heat-affected zone generated after the main electrospark cutting of the workpiece are removed, and all or most of the surface recast layer of the workpiece after the main electrospark cutting is removed;

[0012] Process three: electrolytic cutting finishing stage; in this stage, the parameters of the power supply are adjusted to weak electrolytic cutting processing parameters; the servo control system is driven to change the processing gap between the electrode wire and the workpiece to the weak electrolytic processing gap L3, and when the signal of the oscilloscope in the servo control system and the software status in the control panel show the weak electrolytic processing state, weak electrolytic cutting is performed according to the cutting trajectory preset in the servo control system until the recast layer on the surface of the workpiece is completely removed;

[0013] Process 4: Electrolytic polishing superfinishing stage; in this stage, the parameters of the power supply are adjusted to the electrolytic polishing cutting parameters; the servo control system is driven to change the machining gap between the electrode wire and the workpiece to the electrolytic polishing machining gap L4, and when the signal of the oscilloscope in the servo control system and the software status in the control panel show the electrolytic polishing machining state, electrolytic polishing is performed according to the cutting trajectory preset in the servo control system until the polishing process after the recast layer is removed from the workpiece surface is completed;

[0014] And the spark discharge gap L1, the strong electrolytic machining gap L2, the weak electrolytic machining gap L3 and the electrolytic polishing machining gap L4 increase in sequence.

[0015] Furthermore, the method also includes a circulating liquid supply unit A and a circulating liquid supply unit B connected to the electrolytic cell. During the processing of process one, the electrolytic cell is filled with electrolyte A through the circulating liquid supply unit A; during the processing of process two, process three and process four, the electrolytic cell is filled with electrolyte B through the circulating liquid supply unit B.

[0016] Furthermore, the method also includes an auxiliary liquid injection system for spraying electrolyte onto the electrode wire, and the electrolyte sprayed by the auxiliary liquid injection system flows from top to bottom along the electrode wire; during the processing of process one, the auxiliary liquid injection system sprays electrolyte A provided by the circulating liquid supply unit A onto the electrode wire; during the processing of process two, process three and process four, the auxiliary liquid injection system sprays electrolyte B provided by the circulating liquid supply unit B onto the electrode wire.

[0017] Furthermore, in the electrospark main cutting stage of process one, the electrolyte A inside the electrolytic cell is deionized water or a low-conductivity salt solution with a concentration less than ten percent; in the electrolytic cutting rough machining stage of process two, the electrolytic cutting finishing stage of process three, and the electrolytic polishing super-finishing stage of process four, the electrolyte B inside the electrolytic cell is a high-conductivity salt solution with a concentration greater than ten percent.

[0018] Furthermore, the four processing processes can be changed according to the requirements of the processing object. When the dimensional accuracy, surface roughness, form and position tolerance requirements of the workpiece after processing are not high and a recast layer is required, only process one is performed; when the dimensional accuracy, surface roughness, form and position tolerance requirements of the workpiece after processing are relatively high and no recast layer is required, process one and process two are performed, or process one, process two and process three are performed; when the dimensional accuracy, surface roughness, form and position tolerance requirements of the workpiece after processing are high and no recast layer is required, process one, process two, process three and process four are performed, and process four can be repeated until the requirements are met.

[0019] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a variable-gap electrolytic spark combined cutting processing device, comprising a machine tool Z-axis slide and a machine tool XY-axis slide provided on a CNC machine tool, a one-way wire feeding mechanism is fixedly provided on the machine tool Z-axis slide, the one-way wire feeding mechanism comprises a wire feeding bracket connected to the machine tool Z-axis slide, a wire storage drum is rotatably provided on the wire feeding bracket, an upper wire guide wheel group and a lower wire guide wheel group are symmetrically provided on the wire feeding bracket above and below the wire storage drum; the upper wire guide wheel group comprises an upper wire feeding bracket The wire guide wheels 1, 2 and 3 are provided for rotation, and the structure of the lower wire guide wheel group is the same as that of the upper wire guide wheel group; the electrode wire on the wire storage drum is guided by the wire guide wheels 1, 2 and 3 of the upper wire guide wheel group in sequence, and the electrode wire drawn out from the upper wire guide wheel group is guided by the wire guide wheels 3, 2 and 1 of the lower wire guide wheel group in sequence and then wound with the wire storage drum; the wire travel bracket is also provided with a tensioning mechanism, and the tensioning mechanism includes a linear slide rail provided on the wire travel bracket along the X-axis direction of the CNC machine tool, and the linear slide rail The upper slide is provided with a slide plate, the wire travel bracket is provided with a motor screw transmission mechanism that can drive the slide plate to move, and the slide plate is symmetrically provided with tensioning wheels at positions corresponding to the upper wire guide wheel group and the lower wire guide wheel group, and the electrode wire between the wire guide wheel 1 and the wire guide wheel 2 is tensioned and guided by the tensioning wheel; the wire travel bracket is also provided with a conductive block that is in conductive contact with the electrode wire; the XY axis slide of the machine tool is provided with an electrolytic cell, an anode clamp is fixed in the electrolytic cell, and a circulating liquid supply unit A and a circulating liquid supply unit B are provided on one side of the CNC machine tool; the circulating The liquid supply unit A includes a liquid storage tank, a liquid outlet pipe of the liquid storage tank is connected to a hydraulic pump, the liquid outlet of the hydraulic pump is connected to the liquid inlet of the electrolytic cell through a liquid delivery pipe, and the liquid outlet of the electrolytic cell is connected to the reflux port of the liquid storage tank through a reflux pipe; the circulating liquid supply unit B has the same structure as the circulating liquid supply unit A, and the circulating liquid supply unit B is connected to another group of liquid inlets and reflux ports of the electrolytic cell; it also includes a power supply and an oscilloscope, the positive and negative electrodes of the power supply are electrically connected to the anode clamp and the conductive block respectively, and the negative electrode of the power supply is also electrically connected to the oscilloscope.

[0020] Furthermore, sliders are provided on the slide plate at positions corresponding to the tensioning wheels, and the tensioning wheels are arranged on the sliders corresponding thereto. Limit plates are fixedly provided on both sides of the sliders on the slide plate, horizontally arranged guide rods are fixedly provided between the limit plates, and the sliders are slidably nested on the guide rods. A spring is sleeved between the limit plate on one side of the guide rod and the slider, and the elastic force of the spring acts on the slider to cause the tensioning wheel to generate elastic tensioning force on the electrode wire.

[0021] Furthermore, the unidirectional wire feeding mechanism also includes a tension detection component, which includes a fixed plate fixedly provided on the wire feeding bracket at a position corresponding to the second guide wire wheel, and a pressure sensor is provided on the fixed plate, and a connecting block is fixed on the pressure sensor, and the second guide wire wheel is arranged on the corresponding connecting block.

[0022] Furthermore, an upper wire guide nozzle is provided below the wire guide wheel 3 on the upper side of the wire feeding bracket, and a lower wire guide nozzle is provided below the wire guide wheel 3 on the lower side of the wire feeding bracket, and both the upper wire guide nozzle and the lower wire guide nozzle are conical duct structures; a liquid inlet A and a liquid inlet B are also provided on the outer wall of the upper wire guide nozzle; the circulating liquid supply unit A also includes an electromagnetic three-way valve on the liquid delivery pipe, and the remaining pipe interface of the electromagnetic three-way valve is connected to the liquid inlet A through an auxiliary liquid supply pipe, and the electromagnetic three-way valve of the circulating liquid supply unit B is connected to the liquid inlet B through another auxiliary liquid supply pipe.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. Through the combined use of the main EDM cutting stage and the electrolytic machining stage, the waist bulge, heat-affected zone, and recast layer defects of thick and large depth-diameter ratio workpieces can be completely removed; this makes up for the shortcomings of the current processing technology for thick and large depth-diameter ratio workpieces in the aerospace, nuclear industry and other application fields that uses EDM wire cutting to repeatedly trim but cannot remove the recast layer.

[0025] 2. Through the selection and use of four stages, namely, process 1, the main EDM cutting stage, process 2, the rough electrolytic cutting stage, process 3, the finishing electrolytic cutting stage, and process 4, the electrolytic polishing super finishing stage, the processing needs of large thickness and large depth-to-diameter ratio workpieces with or without recast layer requirements, different dimensional accuracy, surface roughness, form and position tolerances, etc. can be met. The variable gap electrolytic EDM combined cutting processing equipment has a simple structure, is easy to operate, and has high processing flexibility.

[0026] 3. In the main EDM cutting stage, the electrolyte A sprayed by the auxiliary injection system flows from top to bottom along the electrode wire, realizing the flow renewal of the electrolyte in the machining gap and the removal of the electrolysis products, thereby improving the main EDM cutting efficiency and cutting accuracy; in the electrolytic cutting rough machining stage, the electrolytic cutting finishing stage and the electrolytic polishing super finishing stage, the electrolyte B sprayed by the auxiliary injection system flows from top to bottom along the electrode wire, realizing the flow renewal of the electrolyte in the machining gap and the removal of the electrolysis products, thereby improving the strong electrolytic cutting efficiency, the weak electrolytic cutting efficiency, the electrolytic polishing efficiency and the finishing accuracy.

[0027] 4. After the electrode wire performs the main EDM cutting on the workpiece, firstly, the electrode wire performs strong electrolytic cutting to remove the waist drum and heat affected zone produced by the main EDM cutting of the workpiece, and completes the removal of all or most of the surface recast layer of the workpiece after the main EDM cutting; then the electrode wire performs weak electrolytic cutting on the workpiece to ensure the complete removal of the surface recast layer of the workpiece; finally, the electrode wire performs polishing on the surface of the workpiece after the recast layer is removed. The processing procedures are reasonably set, and the processing efficiency is high for workpieces with high thickness and large depth-to-diameter ratio that have high requirements on dimensional accuracy, surface roughness, and form and position tolerances and require no recast layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the waist bulge of a workpiece during the existing electrospark cutting process;

[0029] Figure 2 This is a schematic diagram of the structure of the electrode wire of the present invention when cutting a workpiece;

[0030] Figure 3 A schematic diagram of a gap change path of an electrode wire relative to a workpiece during variable gap cutting processing of the present invention;

[0031] Figure 4 It is a schematic diagram of the change of the gap between the electrode wire and the workpiece at different cutting stages during the variable gap cutting process of the present invention;

[0032] Figure 5 It is a schematic diagram of the structure of the cutting processing device of the present invention;

[0033] Figure 6 It is a schematic diagram of the electrical connection between the electrode wire, the workpiece and the power supply of the present invention;

[0034] Figure 7 It is a structural schematic diagram of the one-way wire feeding mechanism of the present invention;

[0035] Figure 8 It is a partial enlarged view of the tensioning mechanism of the present invention;

[0036] Fig. 9 This is a schematic diagram of the structure of the tension detection component of the present invention;

[0037] Fig.10 It is a cross-sectional view of the upper wire guide nozzle of the present invention;

[0038] Fig.11 It is a schematic diagram of the structure of the circulating liquid supply unit A and the circulating liquid supply unit B of the present invention.

[0039] In the figure: 1, electrode wire; 2, workpiece; 3, machine tool Z-axis slide; 4, one-way wire feeding mechanism; 41, wire feeding bracket; 42, wire storage drum; 43, upper wire guide wheel group; 431, wire guide wheel one; 432, wire guide wheel two; 433, wire guide wheel three; 44, lower wire guide wheel group; 45, tensioning mechanism; 451, linear slide rail; 452, slide plate; 453, motor screw transmission mechanism; 454, limit plate; 455, guide rod; 456, slide block; 457, tensioning wheel; 458, spring; 46, tension detection Measuring components; 461, connecting block; 462, pressure sensor; 463, fixing plate; 47, conductive block; 48, upper wire guide nozzle; 481, liquid inlet A; 482, liquid inlet B; 49, lower wire guide nozzle; 5, machine tool XY axis slide; 6, anode clamp; 7, electrolytic cell; 8, circulating liquid supply unit A; 81, liquid storage tank; 82, hydraulic pump; 83, liquid delivery pipe; 84, electromagnetic three-way valve; 85, auxiliary liquid supply pipe; 86, reflux pipe; 9, circulating liquid supply unit B; 10, power supply; 11, oscilloscope. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Embodiment 1

[0041] See also Figure 2-5 and Fig.11 The present invention provides a technical solution: a variable gap electrolytic spark combined cutting method, the method comprising a CNC machine tool provided with a one-way wire feeding mechanism 4 for driving an electrode wire 1 to feed one-way wire, the one-way wire feeding mechanism 4 being provided with a tensioning mechanism 45 for tensioning the electrode wire 1, and also comprising a circulating liquid supply unit A8, a circulating liquid supply unit B9 and an auxiliary liquid injection system for spraying electrolyte to the electrode wire 1, comprising the following processing steps:

[0042] Before the cutting process begins, the workpiece 2 is fixed in the electrolytic cell 7 and immersed in the electrolyte. The positive and negative electrodes of the power supply 10 are electrically connected to the workpiece 2 and the electrode wire 1 respectively. The negative electrode of the power supply 10 is also electrically connected to the oscilloscope 11, and the power supply 10 is turned on. After the electrode wire 1 is tensioned by the tensioning mechanism 45, it is driven by the one-way wire feeding mechanism 4 to feed the wire in one direction from top to bottom.

[0043] Process 1: EDM main cutting stage; drive the servo control system to change the machining gap between the electrode wire 1 and the workpiece 2 into a spark discharge gap L1, and when the signal of the oscilloscope 11 in the servo control system and the software status in the control panel change from a no-load state to a spark discharge state, perform EDM cutting according to the cutting trajectory preset in the servo control system until the EDM main cutting of the workpiece 2 is completed;

[0044] In this stage, the parameters of the power source 10 are adjusted to the parameters of the wire EDM machining, and the electrolyte A is filled in the electrolytic cell 7 through the circulating liquid supply unit A8; the auxiliary liquid injection system sprays the electrolyte A provided by the circulating liquid supply unit A8 onto the electrode wire 1, and the electrolyte A sprayed by the auxiliary liquid injection system flows from top to bottom along the electrode wire 1, so as to realize the flow renewal of the electrolyte in the machining gap and the expulsion of the electrolysis products, thereby improving the main EDM cutting efficiency and cutting accuracy;

[0045] Process 2: electrolytic cutting rough machining stage; drive the servo control system to change the machining gap between the electrode wire 1 and the workpiece 2 into a strong electrolytic machining gap L2, and when the signal of the oscilloscope 11 in the servo control system and the software status in the control panel show the strong electrolytic machining state, perform strong electrolytic cutting according to the cutting trajectory preset in the servo control system until the waist drum and heat affected zone generated after the main electrospark cutting of the workpiece 2 are removed, and all or most of the surface recast layer of the workpiece 2 after the main electrospark cutting is removed;

[0046] In this stage, the parameters of the power source 10 are adjusted to the strong electrolytic cutting processing parameters, and the electrolyte B is filled in the electrolytic cell 7 through the circulating liquid supply unit B9; the auxiliary liquid injection system sprays the electrolyte B provided by the circulating liquid supply unit B9 onto the electrode wire 1, and the electrolyte B sprayed by the auxiliary liquid injection system flows from top to bottom along the electrode wire 1, so as to realize the flow renewal of the electrolyte in the processing gap and the expulsion of the electrolytic products, thereby improving the strong electrolytic cutting efficiency and the finishing accuracy;

[0047] Process three: electrolytic cutting finishing stage; driving the servo control system so that the machining gap between the electrode wire 1 and the workpiece 2 becomes a weak electrolytic machining gap L3, when the signal of the oscilloscope 11 in the servo control system and the software status in the control panel show a weak electrolytic machining state, weak electrolytic cutting is performed according to the cutting trajectory preset in the servo control system until the recast layer on the surface of the workpiece 2 is completely removed;

[0048] In this stage, the parameters of the power supply 10 are adjusted to the weak electrolytic cutting processing parameters, and the electrolyte B is filled in the electrolytic cell 7 through the circulating liquid supply unit B9; the auxiliary liquid injection system sprays the electrolyte B provided by the circulating liquid supply unit B9 onto the electrode wire 1, and the electrolyte B sprayed by the auxiliary liquid injection system flows from top to bottom along the electrode wire 1, so as to realize the flow renewal of the electrolyte in the processing gap and the expulsion of the electrolytic products, thereby improving the weak electrolytic cutting efficiency and the finishing accuracy;

[0049] Process 4: Electrolytic polishing super finishing stage; driving the servo control system so that the machining gap between the electrode wire 1 and the workpiece 2 becomes the electrolytic polishing machining gap L4, when the signal of the oscilloscope 11 in the servo control system and the software status in the control panel show the electrolytic polishing machining state, electrolytic polishing is performed according to the cutting trajectory preset in the servo control system until the polishing machining after the recast layer is removed from the surface of the workpiece 2 is completed;

[0050] In this stage, the parameters of the power supply 10 are adjusted to the electrolytic polishing cutting processing parameters, and the electrolyte B is filled in the electrolytic cell 7 through the circulating liquid supply unit B9; the auxiliary liquid injection system sprays the electrolyte B provided by the circulating liquid supply unit B9 onto the electrode wire 1, and the electrolyte B sprayed by the auxiliary liquid injection system flows from top to bottom along the electrode wire 1, so as to realize the flow renewal of the electrolyte in the processing gap and the expulsion of the electrolytic products, thereby improving the electrolytic polishing efficiency and the finishing accuracy;

[0051] And the spark discharge gap L1, the strong electrolytic machining gap L2, the weak electrolytic machining gap L3 and the electrolytic polishing machining gap L4 increase in sequence.

[0052] Furthermore, in the electric spark main cutting stage of process one, the electrolyte A inside the electrolytic tank 7 is deionized water or a low conductivity salt solution with a concentration less than ten percent; in the electrolytic cutting rough machining stage of process two, the electrolytic cutting finishing stage of process three and the electrolytic polishing super finishing stage of process four, the electrolyte B inside the electrolytic tank 7 is a high conductivity salt solution with a concentration greater than ten percent; the low conductivity salt solution and the high conductivity salt solution can be sodium nitrate solution, sodium chloride solution, ethylene glycol sodium chloride solution, ethylene glycol sodium nitrate solution, etc.

[0053] Furthermore, the four processing processes can be changed according to the requirements of the processing object. When the dimensional accuracy, surface roughness, form and position tolerance requirements of the workpiece 2 after processing are not high and a recast layer is required, only process one is performed; when the dimensional accuracy, surface roughness, form and position tolerance requirements of the workpiece 2 after processing are relatively high and no recast layer is required, process one and process two are performed, or process one, process two and process three are performed; when the dimensional accuracy, surface roughness, form and position tolerance requirements of the workpiece 2 after processing are high and no recast layer is required, process one, process two, process three and process four are performed, and process four can be repeated until the requirements are met.

[0054] The variable gap electrolytic spark combined cutting processing method disclosed in the present embodiment first makes the processing gap between the electrode wire 1 and the workpiece 2 a spark discharge gap, and the electrode wire 1 performs spark main cutting on the workpiece 2 according to a preset cutting trajectory; then, by repeatedly changing the processing gap between the electrode wire 1 and the workpiece 2, the surface of the workpiece 2 after the spark main cutting is successively subjected to strong electrolytic cutting, weak electrolytic cutting and electrolytic polishing, so as to complete the removal of the waist drum degree, heat affected zone and recast layer of the surface of the workpiece 2 after the spark main cutting, and complete the polishing processing after the recast layer is removed from the surface of the workpiece 2; because the spark discharge gap L1, the strong electrolytic processing gap L2, the weak electrolytic processing gap L3 and the electrolytic polishing processing gap L4 are successively increased, not only the gap between the electrode wire 1 and the workpiece 2 is ensured, but also the gap between the electrode wire 1 and the workpiece 2 is ensured. Only electrolytic reaction occurs, and the machining gap between the electrode wire 1 and the workpiece 2 increases, so that the electrolyte fills the machining gap, and the flushing effect of the middle section of the machining gap is good, which accelerates the rapid renewal flow of the electrolyte inside the machining gap, so that the electrolytic products in the machining gap are quickly discharged, which not only improves the machining efficiency, but also avoids the spark discharge between the electrode wire 1 and the middle section of the workpiece 2 during the electrolytic dressing process, which leads to a more obvious waist drum after electrolytic dressing. The electrode wire 1 has a good dressing effect on the surface of the workpiece 2 by strong electrolytic cutting, weak electrolytic cutting and electrolytic polishing; through the combined use of the main electrospark cutting stage and the electrolytic machining stage, the recast layer of the workpiece 2 with a large thickness and a large depth-to-diameter ratio can be removed, and its waist drum, heat-affected zone, and recast layer defects can be completely removed;

[0055] Through the selection and use of four stages, namely, process one, electric spark main cutting stage, process two, electrolytic cutting rough machining stage, process three, electrolytic cutting finishing stage, and process four, electrolytic polishing super finishing stage, the processing needs of large thickness and large depth-to-diameter ratio workpiece 2 with or without recast layer requirements, different dimensional accuracy, surface roughness, form and position tolerances, etc. can be met, with high processing flexibility. Embodiment 2

[0056] See also Figure 2-11 , the present invention provides a technical solution: a variable gap electrolytic spark combined cutting processing device, comprising a machine tool Z-axis slide 3 and a machine tool XY-axis slide 5 provided on a CNC machine tool;

[0057] The Z-axis slide 3 of the machine tool is fixedly provided with a one-way wire feeding mechanism 4, which includes a wire feeding bracket 41 connected to the Z-axis slide 3 of the machine tool, a wire storage drum 42 is rotatably provided on the wire feeding bracket 41, and an upper wire guide wheel group 43 and a lower wire guide wheel group 44 are symmetrically provided above and below the wire storage drum 42 on the wire feeding bracket 41; the upper wire guide wheel group 43 includes a wire guide wheel 1 431, a wire guide wheel 2 432 and a wire guide wheel 3 433 rotatably provided on the wire feeding bracket 41, The lower wire guide wheel group 44 has the same structure as the upper wire guide wheel group 43; the electrode wire 1 on the wire storage drum 42 is guided by the wire guide wheel 1 431, the wire guide wheel 2 432 and the wire guide wheel 3 433 of the upper wire guide wheel group 43 in sequence, and the electrode wire 1 drawn out from the upper wire guide wheel group 43 is guided by the wire guide wheel 3 433, the wire guide wheel 2 432 and the wire guide wheel 1 431 of the lower wire guide wheel group 44 in sequence and then wound around the wire storage drum 42; the wire travel bracket 41 is also provided with a tensioning mechanism 45;

[0058] The tensioning mechanism 45 includes a linear slide 451 provided on the wire travel bracket 41 along the X-axis direction of the CNC machine tool, a slide plate 452 is slidably provided on the linear slide 451, a motor screw transmission mechanism 453 that can drive the slide plate 452 to move is provided on the wire travel bracket 41, and tensioning wheels 457 are symmetrically provided on the slide plate 452 at positions corresponding to the upper wire guide wheel group 43 and the lower wire guide wheel group 44, and the electrode wire 1 between the wire guide wheel 1 431 and the wire guide wheel 2 432 is tensioned and guided by the tensioning wheel 457; the position of the slide plate 452 corresponding to the tensioning wheel 457 Slide blocks 456 are provided at the positions, and tensioning wheels 457 are provided on the corresponding slide blocks 456. Limiting plates 454 are fixedly provided on both sides of the slide blocks 456 on the slide block 452. A horizontally arranged guide rod 455 is fixedly provided between the limiting plates 454. The slide blocks 456 are slidably nested on the guide rods 455. A spring 458 is sleeved between the limiting plate 454 on one side of the guide rod 455 and the slide blocks 456. The elastic force of the spring 458 acts on the slide blocks 456 to make the tensioning wheel 457 generate elastic tensioning force on the electrode wire 1.

[0059] The one-way wire feeding mechanism 4 further includes a tension detection assembly 46, which includes a fixed plate 463 fixedly provided on the wire feeding bracket 41 at a position corresponding to the second wire guide wheel 432, and a pressure sensor 462 is provided on the fixed plate 463, and a connecting block 461 is fixedly provided on the pressure sensor 462, and the second wire guide wheel 432 is arranged on the corresponding connecting block 461;

[0060] The wire support 41 is also provided with a conductive block 47 that is in conductive contact with the electrode wire 1; an upper wire guide nozzle 48 is provided below the wire guide wheel 3 433 on the upper side of the wire support 41, and a lower wire guide nozzle 49 is provided below the wire guide wheel 3 433 on the lower side of the wire support 41, and both the upper wire guide nozzle 48 and the lower wire guide nozzle 49 are tapered catheter structures; a liquid inlet A481 and a liquid inlet B482 are also provided on the outer wall of the upper wire guide nozzle 48;

[0061] The XY axis slide 5 of the machine tool is provided with an electrolytic cell 7, in which an anode fixture 6 is fixedly provided, and a circulating liquid supply unit A8 and a circulating liquid supply unit B9 are provided on one side of the CNC machine tool; the circulating liquid supply unit A8 includes a liquid storage tank 81, and the liquid outlet pipe of the liquid storage tank 81 is connected to a hydraulic pump 82, and the liquid outlet of the hydraulic pump 82 is connected to the liquid inlet of the electrolytic cell 7 through a liquid delivery pipe 83, and the liquid outlet of the electrolytic cell 7 is connected to the reflux port of the liquid storage tank 81 through a reflux pipe 86; the circulating liquid supply unit A8 also includes an electromagnetic three-way valve 84 provided on the liquid delivery pipe 83, and the remaining pipe interface of the electromagnetic three-way valve 84 is connected to the liquid inlet A481 through an auxiliary liquid supply pipe 85. The circulating liquid supply unit B9 has the same structure as the circulating liquid supply unit A8, and the circulating liquid supply unit B9 is connected to another group of liquid inlet and reflux ports of the electrolytic cell 7, and the electromagnetic three-way valve 84 of the circulating liquid supply unit B9 is connected to the liquid inlet B482 through another auxiliary liquid supply pipe 85; the electrolyte contained in the liquid storage tank 81 of the circulating liquid supply unit A8 is electrolyte A, and the electrolyte contained in the liquid storage tank 81 of the circulating liquid supply unit B9 is electrolyte B; in the circulating liquid supply unit A8 and the circulating liquid supply unit B9, an auxiliary liquid injection system is formed by a hydraulic pump 82, a liquid delivery pipe 83, an electromagnetic three-way valve 84, an auxiliary liquid supply pipe 85 and an upper wire guide nozzle 48;

[0062] It also includes a power supply 10 and an oscilloscope 11 . The positive and negative electrodes of the power supply 10 are electrically connected to the anode fixture 6 and the conductive block 47 , respectively. The negative electrode of the power supply 10 is also electrically connected to the oscilloscope 11 .

[0063] Working principle:

[0064] Fix the workpiece 2 on the anode fixture 6, and electrically connect the positive and negative electrodes of the power supply 10 to the workpiece 2 and the electrode wire 1 respectively, and draw the electrolyte A into the electrolytic cell 7 through the hydraulic pump 82, the liquid delivery pipe 83 and the liquid storage tank 81 in the circulating liquid supply unit A8 until the workpiece 2 is immersed in the electrolyte A, and drive the slide plate 452 to move through the motor screw transmission mechanism 453, and the spring 458 is deformed by the tension of the electrode wire 1 on the tensioning wheel 457, and the elastic force generated by the spring 458 reacts on the slide plate 456 to make the tensioning wheel 457 tension the electrode wire 1, and the tensioning force of the electrode wire 1 is detected by the pressure sensor 462. When the tensioning force of the electrode wire 1 reaches a preset value, the electrode wire 1 is driven by the wire storage drum 42 to perform unidirectional wire feeding;

[0065] The anode fixture 6 and the workpiece 2 are moved by the XY axis slide 5 of the machine tool, and the machining gap between the electrode wire 1 and the workpiece 2 is changed to the spark discharge gap L1. The parameters of the power supply 10 are adjusted to the EDM machining parameters. The signal of the oscilloscope 11 in the servo control system of the CNC machine tool and the software status in the control panel are displayed from the no-load state to the spark discharge state. The XY axis slide 5 of the machine tool drives the workpiece 2 to move according to the cutting trajectory preset by the servo control system, so that the electrode wire 1 performs EDM on the workpiece 2. The spark cutting is performed until the main spark cutting of the workpiece 2 is completed; and in the process of the main spark cutting, the electrolyte A is supplied to the liquid inlet A481 of the upper wire guide nozzle 48 through the hydraulic pump 82, the liquid delivery pipe 83, the electromagnetic three-way valve 84 and the auxiliary liquid supply pipe 85 in the circulating liquid supply unit A8, and the electrolyte A in the upper wire guide nozzle 48 is ejected from the wire guide port at its lower end and flows from top to bottom along the electrode wire 1, so as to realize the flow renewal of the electrolyte in the processing gap and the expulsion of the electrolysis products, thereby improving the main spark cutting efficiency and cutting accuracy;

[0066] After the main EDM cutting is completed, the electrolyte A in the electrolytic tank 7 is discharged through the reflux pipe 86 of the circulating liquid supply unit A8, and the electrolyte B is drawn into the electrolytic tank 7 through the hydraulic pump 82, the liquid delivery pipe 83 and the liquid storage tank 81 in the circulating liquid supply unit B9 until the workpiece 2 is immersed in the electrolyte A, and the workpiece 2 is driven by the machine tool XY axis slide 5 to deviate a distance away from the electrode wire 1, and the machining gap between the electrode wire 1 and the workpiece 2 is changed to a strong electrolytic machining gap L2, and the parameters of the power supply 10 are adjusted to the strong electrolytic cutting processing parameters, the signal of the oscilloscope 11 in the servo control system of the CNC machine tool and the software status in the control panel are displayed as the strong electrolytic machining state, and the machine tool is operated according to the cutting trajectory preset by the servo control system. The XY-axis slide 5 drives the workpiece 2 to move, so that the electrode wire 1 performs strong electrolytic cutting on the workpiece 2 until the waist drum and heat-affected zone generated after the main electrospark cutting of the workpiece 2 are removed, and all or most of the surface recast layer after the main electrospark cutting of the workpiece 2 is removed; and in the process of strong electrolytic cutting, the electrolyte B is supplied to the liquid inlet B482 of the upper wire guide nozzle 48 through the hydraulic pump 82, the liquid delivery pipe 83, the electromagnetic three-way valve 84 and the auxiliary liquid supply pipe 85 in the circulating liquid supply unit B9, and the electrolyte B in the upper wire guide nozzle 48 is ejected from the wire guide port at its lower end and flows from top to bottom along the electrode wire 1, so as to realize the flow renewal of the electrolyte in the processing gap and the expulsion of the electrolytic products, thereby improving the strong electrolytic cutting efficiency and the finishing accuracy;

[0067] After the strong electrolytic cutting is completed, the workpiece 2 is driven by the machine tool XY axis slide 5 to deviate a distance away from the electrode wire 1, and the machining gap between the electrode wire 1 and the workpiece 2 is changed to a weak electrolytic machining gap L3, and the parameters of the power supply 10 are adjusted to the weak electrolytic cutting machining parameters. The signal of the oscilloscope 11 in the servo control system of the CNC machine tool and the software status in the control panel are displayed as the weak electrolytic machining state. The machine tool XY axis slide 5 drives the workpiece 2 to move according to the cutting trajectory preset by the servo control system, so that the electrode wire 1 performs weak electrolytic cutting on the workpiece 2 until the recast layer on the surface of the workpiece 2 is completely removed; and in the process of weak electrolytic cutting, the electrolyte B is supplied to the liquid inlet B482 of the upward wire guide nozzle 48 in the circulating liquid supply unit B9, so as to realize the flow renewal of the electrolyte in the machining gap and the removal of the electrolytic products, thereby improving the strong electrolytic cutting efficiency and finishing accuracy;

[0068] After the weak electrolytic cutting is completed, the workpiece 2 is driven by the machine tool XY axis slide 5 to deviate a distance away from the electrode wire 1, and the processing gap between the electrode wire 1 and the workpiece 2 is changed to the electrolytic polishing processing gap L4, and the parameters of the power supply 10 are adjusted to the electrolytic polishing cutting processing parameters. The signal of the oscilloscope 11 in the servo control system of the CNC machine tool and the software status in the control panel are displayed as the electrolytic polishing processing state. The machine tool XY axis slide 5 drives the workpiece 2 to move according to the cutting trajectory preset by the servo control system, so that the electrode wire 1 electrolytically polishes the workpiece 2 until the polishing processing after the recast layer on the surface of the workpiece 2 is completed; and in the process of electrolytic polishing, the electrolyte B is supplied to the liquid inlet B482 of the upward wire guide nozzle 48 in the circulating liquid supply unit B9, so as to realize the flow renewal of the electrolyte in the processing gap and the removal of the electrolytic products, thereby improving the strong electrolytic cutting efficiency and finishing accuracy.

[0069] The variable gap electrolytic spark combined cutting processing device disclosed in this embodiment tensions the electrode wire 1 through the tensioning mechanism 45 provided on the one-way wire feeding mechanism 4, and drives the slide plate 452 to move through the motor screw transmission mechanism 453 to quickly adjust the tension of the electrode wire 1, absorbs the high-frequency vibration generated during the processing through the spring 458, improves the adjustment response speed of the tension of the electrode wire 1, and can play a buffering role when the tension of the electrode wire 1 suddenly changes, thereby reducing the probability of wire breakage; the tensioning mechanism 45 can ensure the tension of the electrode wire 1, and prevent the electrode wire 1 in the processing gap from breaking. The electrode wire 1 generates a certain deflection during processing, which can effectively prevent the electrode wire 1 from generating a bulge in the process of cutting the workpiece 2; after the main EDM cutting, the workpiece 2 is driven to deviate away from the electrode wire 1 through the XY axis slide 5 of the machine tool, and the bulge, heat affected zone and recast layer generated after the main EDM cutting are electrolytically cut, trimmed and electrolytically polished; the processing requirements of large thickness and large depth-to-diameter ratio workpieces 2 with or without recast layer requirements, different dimensional accuracy, surface roughness, form and position tolerances, etc. can be met, and the processing flexibility is high; the structure is simple, the cutting accuracy is high, and the cutting surface quality is good.

[0070] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A variable gap electrolytic spark combined cutting method, the method comprising: a unidirectional wire feeding mechanism (4) for driving an electrode wire (1) to feed unidirectional wire on a numerically controlled machine tool; a tensioning mechanism (45) for tensioning the electrode wire (1) is provided on the unidirectional wire feeding mechanism (4); the method is characterized in that: The process includes the following steps: before the start of processing, the workpiece (2) is fixed in the electrolytic cell (7), the positive electrode and the negative electrode of the power source (10) are electrically connected to the workpiece (2) and the electrode wire (1) respectively, and the power source (10) is turned on; after the electrode wire (1) is tensioned by the tensioning mechanism (45), it is driven by the one-way wire feeding mechanism (4) to feed the wire in one direction from top to bottom; Process 1: main electric spark cutting stage; in this stage, the parameters of the power source (10) are adjusted to the parameters of the electric spark wire cutting process; the servo control system is driven to change the processing gap between the electrode wire (1) and the workpiece (2) into the spark discharge gap L1, and the electric spark cutting is performed according to the cutting trajectory preset in the servo control system until the main electric spark cutting of the workpiece (2) is completed; Process 2: electrolytic cutting rough machining stage; in this stage, the parameters of the power source (10) are adjusted to the strong electrolytic cutting machining parameters; the servo control system is driven to change the machining gap between the electrode wire (1) and the workpiece (2) to the strong electrolytic machining gap L2, and the strong electrolytic cutting is performed according to the cutting trajectory preset in the servo control system until the waist drum and heat-affected zone generated by the main electrospark cutting of the workpiece (2) are removed, and all or most of the surface recast layer of the workpiece (2) after the main electrospark cutting is removed; Process three: electrolytic cutting finishing stage; in this stage, the parameters of the power source (10) are adjusted to weak electrolytic cutting processing parameters; the servo control system is driven to change the processing gap between the electrode wire (1) and the workpiece (2) to the weak electrolytic processing gap L3, and weak electrolytic cutting is performed according to the cutting trajectory preset in the servo control system until the recast layer on the surface of the workpiece (2) is completely removed; Process 4: electrolytic polishing superfinishing stage; in this stage, the parameters of the power supply (10) are adjusted to electrolytic polishing cutting parameters; the servo control system is driven to change the machining gap between the electrode wire (1) and the workpiece (2) to the electrolytic polishing machining gap L4, and electrolytic polishing is performed according to the cutting trajectory preset in the servo control system until the polishing process is completed after the recast layer is removed from the surface of the workpiece (2); The method further comprises a circulating liquid supply unit A (8) and a circulating liquid supply unit B (9) connected to the electrolytic cell (7); during the processing of process one, the electrolytic cell (7) is filled with electrolyte A through the circulating liquid supply unit A (8); during the processing of process two, process three and process four, the electrolytic cell (7) is filled with electrolyte B through the circulating liquid supply unit B (9); the method further comprises an auxiliary liquid injection system for spraying electrolyte onto the electrode wire (1), and the electrolyte sprayed by the auxiliary liquid injection system flows from top to bottom along the electrode wire (1); during the processing of process one, the auxiliary liquid injection system sprays the electrolyte A provided by the circulating liquid supply unit A (8) onto the electrode wire (1); during the processing of process two, process three and process four, the auxiliary liquid injection system sprays the electrolyte B provided by the circulating liquid supply unit B (9) onto the electrode wire (1).

2. The variable gap electrolytic electric spark combined cutting method according to claim 1, characterized in that: In the electrospark main cutting stage of the process one, the electrolyte A inside the electrolytic tank (7) is deionized water or a low-conductivity salt solution with a concentration of less than 10 percent; in the electrolytic cutting rough machining stage of the process two, the electrolytic cutting finishing stage of the process three, and the electrolytic polishing super-finishing stage of the process four, the electrolyte B inside the electrolytic tank (7) is a high-conductivity salt solution with a concentration of greater than 10 percent.

3. The variable gap electrolytic electric spark combined cutting method according to claim 1, characterized in that: The four processing steps can be changed according to the requirements of the processing object. When the dimensional accuracy, surface roughness, and form and position tolerance of the workpiece (2) after processing are not high and a recast layer is required, only process one is performed; when the dimensional accuracy, surface roughness, and form and position tolerance of the workpiece (2) after processing are relatively high and no recast layer is required, process one and process two are performed, or process one, process two, and process three are performed; when the dimensional accuracy, surface roughness, and form and position tolerance of the workpiece (2) after processing are high and no recast layer is required, process one, process two, process three, and process four are performed, and process four can be repeated until the requirements are met.

4. A variable gap electrolytic spark combined cutting processing device, comprising a machine tool Z-axis slide (3) and a machine tool XY-axis slide (5) provided on a numerically controlled machine tool, characterized in that: A one-way wire feeding mechanism (4) is fixedly provided on the Z-axis slide (3) of the machine tool. The one-way wire feeding mechanism (4) comprises a wire feeding bracket (41) connected to the Z-axis slide (3) of the machine tool. A wire storage drum (42) is rotatably provided on the wire feeding bracket (41). An upper wire guide wheel group (43) and a lower wire guide wheel group (44) are symmetrically provided above and below the wire storage drum (42) on the wire feeding bracket (41). The upper wire guide wheel group (43) comprises a wire guide wheel 1 (431), a wire guide wheel 2 (432) and a wire guide wheel 3 (433) rotatably provided on the wire feeding bracket (41), and the structure of the lower wire guide wheel group (44) is the same as that of the upper wire guide wheel group (43). The electrode wire (1) on the wire storage drum (42) is sequentially The electrode wire (1) is guided by the wire guide wheel 1 (431), the wire guide wheel 2 (432) and the wire guide wheel 3 (433) of the upper wire guide wheel group (43), and is guided by the wire guide wheel 3 (433), the wire guide wheel 2 (432) and the wire guide wheel 1 (431) of the lower wire guide wheel group (44) in sequence, and then is wound around the wire storage drum (42); the wire travel support (41) is also provided with a tensioning mechanism (45), the tensioning mechanism (45) comprises a linear slide rail (451) provided on the wire travel support (41) along the X-axis direction of the CNC machine tool, a slide plate (452) is slidably provided on the linear slide rail (451), and a motor capable of driving the slide plate (452) to move is provided on the wire travel support (41). A lead screw transmission mechanism (453); tensioning wheels (457) are symmetrically arranged on the slide plate (452) at positions corresponding to the upper guide wheel group (43) and the lower guide wheel group (44); and the electrode wire (1) between the first guide wheel (431) and the second guide wheel (432) is tensioned and guided by the tensioning wheel (457); the wire support (41) is also provided with a conductive block (47) in conductive contact with the electrode wire (1); an electrolytic cell (7) is arranged on the XY axis slide table (5) of the machine tool, an anode clamp (6) is fixedly arranged in the electrolytic cell (7), and a circulating liquid supply unit A (8) and a circulating liquid supply unit B (9) are arranged on one side of the CNC machine tool; the circulating liquid supply unit A (8) includes a liquid storage tank (81), a liquid storage tank (82) and a liquid storage tank (83). The liquid outlet pipe of the box (81) is connected to a hydraulic pump (82), the liquid outlet of the hydraulic pump (82) is connected to the liquid inlet of the electrolytic cell (7) through a liquid delivery pipe (83), and the liquid outlet of the electrolytic cell (7) is connected to the reflux port of the liquid storage box (81) through a reflux pipe (86); the circulating liquid supply unit B (9) has the same structure as the circulating liquid supply unit A (8), and the circulating liquid supply unit B (9) is connected to another group of liquid inlets and reflux ports of the electrolytic cell (7); it also includes a power supply (10) and an oscilloscope (11), the positive electrode of the power supply (10) is electrically connected to the anode fixture (6), the negative electrode of the power supply (10) is electrically connected to the conductive block (47), and the negative electrode of the power supply (10) is also electrically connected to the oscilloscope (11); An upper wire guide nozzle (48) is provided below the wire guide wheel 3 (433) located on the upper side of the wire travel support (41), and a lower wire guide nozzle (49) is provided below the wire guide wheel 3 (433) located on the lower side of the wire travel support (41). Both the upper wire guide nozzle (48) and the lower wire guide nozzle (49) are tapered conduit structures; a liquid inlet A (481) and a liquid inlet B (482) are also provided on the outer wall of the upper wire guide nozzle (48); the circulating liquid supply unit A (8) further comprises an electromagnetic three-way valve (84) provided on the liquid delivery pipe (83), the remaining pipe interface of the electromagnetic three-way valve (84) is connected to the liquid inlet A (481) through an auxiliary liquid supply pipe (85), and the electromagnetic three-way valve (84) of the circulating liquid supply unit B (9) is connected to the liquid inlet B (482) through another auxiliary liquid supply pipe (85).

5. The variable gap electrolytic spark combined cutting machining device according to claim 4, characterized in that: The slide plate (452) is provided with a slider (456) at a position corresponding to the tensioning wheel (457), and the tensioning wheel (457) is arranged on the slider (456) corresponding thereto. Limiting plates (454) are fixedly arranged on both sides of the slider (456) on the slide plate (452), and a horizontally arranged guide rod (455) is fixedly arranged between the limiting plates (454), and the slider (456) is slidably nested on the guide rod (455). A spring (458) is sleeved between the limiting plate (454) on one side of the guide rod (455) and the slider (456), and the elastic force of the spring (458) acts on the slider (456) so that the tensioning wheel (457) generates an elastic tensioning force on the electrode wire (1).

6. The variable gap electrolytic electric spark combined cutting machining device according to claim 4, characterized in that: The one-way wire feeding mechanism (4) further comprises a tension detection assembly (46), the tension detection assembly (46) comprising a fixing plate (463) fixedly provided on the wire feeding bracket (41) at a position corresponding to the second guide wire wheel (432), a pressure sensor (462) being provided on the fixing plate (463), a connecting block (461) being fixedly provided on the pressure sensor (462), and the second guide wire wheel (432) being provided on the connecting block (461) corresponding thereto.

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