CN109693009B - Workpiece reciprocating motion assisted axial flushing electrolytic wire cutting machining method and device - Google Patents

Abstract

The invention relates to a method and a device for the reciprocating motion of a workpiece to assist axial flushing electrolytic wire cutting, and belongs to the technical field of electrochemical machining. Its main features are: axial flushing electrolytic wire cutting is used to process large-thickness workpieces, and the workpiece reciprocates along the feeding direction and reciprocates along the axis of the wire electrode while the workpiece is feeding and cutting to the wire electrode. The reciprocating motion of the workpiece changes the distance between the workpiece and the wire electrode, between the workpiece and the nozzle, which is conducive to the rapid flow of the electrolyte in the narrow and long feed end face machining gap, and accelerates the renewal of the electrolyte and the elimination of electrolysis products. Reduce the difference in the flow rate of electrolyte in the machining gap, and improve the machining efficiency and machining accuracy of electrolytic cutting.

Description

Workpiece reciprocating motion assisted axial flushing electrolytic wire cutting processing method and device

technical field

The invention relates to a reciprocating motion-assisted axial flushing electrolytic wire cutting processing method and device, and belongs to the technical field of electrochemical processing.

Background technique

Most of the straight-grained surface structural components of aero-engine blisks, blade tenons, and precision transmission gears are processed by cutting technology, while electrolytic wire cutting uses metal filaments as tool cathodes, and uses metal to produce metal in electrolyte. The principle of electrochemical anode dissolution, a cutting technology for processing and forming metal materials, has the advantages of high processing accuracy, no processing residual stress, no recast layer, no tool loss, etc., so it is suitable for high-precision ruled surface structural parts. Precision cutting.

However, due to the too narrow slit of the electrolytic wire cutting process, it is difficult for fresh electrolyte to enter the processing gap, which reduces the electrolytic reaction speed. And the conductivity changes, which affects the stability of the electrolytic machining, and even a short circuit occurs and the processing is stopped. Especially in the cutting of large-thickness workpieces, as the thickness of the workpiece increases, the deeper and narrower the slit is, the more difficult it is to remove the electrolytic products and the more difficult to update the electrolyte.

For the electrolytic cutting of large-thickness workpieces, the axial flushing electrolytic wire cutting process is often used: the high-speed flowing electrolyte is used to wrap the wire electrode in the axial direction of the wire electrode and quickly rush into the machining gap to wash away the electrolytic products in the machining gap. , to achieve the purpose of quickly updating the electrolyte, improve the efficiency of electrolytic wire cutting and the ability to process large thickness workpieces. However, when the workpiece is too thick, the kerf in the axial direction of the wire electrode is deeper, the machining gap of the feed end face is smaller, and there is little fresh electrolyte that can enter the machining gap, and the wire electrode and the workpiece are affected by the narrow machining gap. Due to the influence of the wall, the flow speed is greatly reduced, and it is difficult to rush to the bottom. The renewal rate of the electrolyte and the removal rate of the electrolytic products are still very slow, and the efficiency of electrolytic cutting and the ability to process large-thickness workpieces are not significantly improved. In addition, the flow rate of the electrolyte is lost along the process in the machining gap. The upper part of the machining gap has a fast flow rate, and the workpiece removal amount is large. The width is narrow and the machining accuracy is reduced. Therefore, how to quickly and efficiently remove the electrolytic products in the slit and update the electrolyte in the slit is still an important problem in electrolytic cutting of large-thickness workpieces.

SUMMARY OF THE INVENTION

Aiming at the problems of difficulty in removing electrolytic products in the slits and difficulty in updating the electrolyte during electrolytic wire cutting, the present invention provides a method and device for electrolytic wire cutting with workpiece reciprocating motion assisting axial flushing.

A workpiece reciprocating motion-assisted axial flushing electrolytic wire cutting processing method is characterized in that: the axial flushing electrolytic wire cutting is used to process the workpiece, and the workpiece performs reciprocating motion while the workpiece performs feeding and cutting motion to the wire electrode, and the workpiece is The reciprocating motion includes the reciprocating motion of the workpiece along the feeding processing direction and the reciprocating motion of the workpiece along the axial direction of the wire electrode; when the workpiece reciprocates along the feeding direction, the distance between the workpiece and the wire electrode changes periodically, and the distance between the two changes periodically. The instantaneous increase of the electrolytic solution is conducive to the more and smoother entry of the electrolyte into the processing gap of the feed end face, completely flushing away the electrolysis products, updating the electrolyte solution, speeding up the electrolysis reaction speed, and improving the efficiency of electrolytic cutting processing; at the same time, due to the processing of the feed end face The increase of the gap allows the electrolyte to flow through it quickly, reduces the loss of the electrolyte flow rate along the process, reduces the flow rate difference of the electrolyte in the upper and lower parts of the machining gap, and improves the machining accuracy of electrolytic cutting; when the workpiece reciprocates along the axis of the wire electrode During the movement, the distance between the workpiece and the nozzle changes periodically, and the flow rate of the electrolyte in the machining gap of the feed end face changes continuously as a whole, so that the electrolyte in the front-end machining gap presents a pulsating flow state, which further accelerates the elimination of electrolytic products and The renewal of the electrolyte improves the processing efficiency of electrolytic cutting; at the same time, the electrolyte adsorbed in the processed slit will be thrown out under the action of inertial force, reducing the flow field of the electrolyte in the slit and reducing the impact on the cutting slit. The stray corrosion of the cut surface improves the machining accuracy of electrolytic cutting.

The device for realizing the reciprocating motion of the workpiece to assist the axial flushing electrolytic wire cutting processing method is characterized in that: it includes a five-axis machine tool system, an anode system, and a wire electrode system; the five-axis machine tool system includes an X-axis table, a Y-axis Worktable, Z-axis table, Xʹ-axis table, Yʹ-axis table, machine tool table; Xʹ-axis of Xʹ-axis table is installed on Yʹ-axis table, and Yʹ-axis of Yʹ-axis table is installed on Z-axis table The Z-axis of the Z-axis table is installed on the Y-axis table, the Y-axis of the Y-axis table is installed on the X-axis table, and the X-axis of the X-axis table is installed on the machine table; the five-axis machine tool system also Including an industrial computer and a motion control card; the anode system includes an anode fixture and a workpiece; the workpiece is installed in the anode fixture, and the anode fixture is installed on the Xʹ-axis worktable; the wire electrode system includes a cathode fixture, a wire electrode, a nozzle, and a guide cavity , a guide; the cathode fixture is fixedly installed on the machine tool column; the wire electrode, the nozzle, the guide cavity and the guide are coaxially installed in the cathode fixture.

The method of the workpiece reciprocating motion assisting the axial flushing electrolytic wire cutting processing device is characterized in that: the feed modules of the X-axis and the Y-axis operate independently, and the joint motion of the X-axis and the Y-axis is controlled to drive the workpiece and the wire electrode The relative feed movement between the two axes; the feed module of the Z axis runs independently, controlling the up and down movement of the Z axis to drive the workpiece to reciprocate along the axial direction of the wire electrode; the feed modules of the Xʹ axis and the Yʹ axis are connected to the X axis and the Y axis. Combined with the feed module, when the workpiece moves relative to the wire electrode, the joint motion of the Xʹ axis and the Yʹ axis is controlled to drive the workpiece to reciprocate along the feed movement direction.

The beneficial effects of the present invention are:

1. The present invention adopts the reciprocating motion of the workpiece to assist the axial flushing electrolytic wire cutting processing method. When the workpiece makes a feeding and cutting motion to the wire electrode, the workpiece reciprocates along the feeding direction, so that the distance between the workpiece and the wire electrode occurs. Periodic changes, the instantaneous increase of the distance between the two is conducive to the more and smoother entry of the electrolyte into the processing gap of the feed end face, thoroughly flushing away the electrolyte products, updating the electrolyte, speeding up the electrolytic reaction speed, and improving the efficiency of electrolytic cutting. At the same time, due to the increase of the machining gap of the feed end face, the electrolyte can flow through it quickly, reducing the loss of the electrolyte flow rate along the process, reducing the flow rate difference of the electrolyte in the upper and lower parts of the machining gap, and improving the machining accuracy of electrolytic cutting ;

2. When the workpiece makes a feeding and cutting motion to the wire electrode, the workpiece reciprocates along the axis of the wire electrode, so that the distance between the workpiece and the nozzle changes periodically, and the flow rate of the electrolyte in the machining gap of the feeding end face changes continuously as a whole. , so that the electrolyte in the machining gap of the feed end face presents a pulsating flow state, which further accelerates the removal of electrolytic products and the renewal of the electrolyte, and improves the efficiency of electrolytic cutting; It is thrown out under the action of force, reducing the flow field of the electrolyte in the slit, reducing the stray corrosion on the cut surface, and improving the machining accuracy of electrolytic cutting;

3. The multi-axis and multi-motion modularized unified and coordinated control method ensures that the relative motion between the workpiece and the wire electrode is relatively independent, that is, the reciprocating motion of the workpiece will not affect the normal feeding motion of the workpiece, which ensures the electrolytic cutting. processing efficiency.

Description of drawings

Fig. 1 is the reciprocating motion of workpiece auxiliary axial flushing liquid electrolytic wire cutting overall device structure schematic diagram;

Fig. 2 is the schematic diagram of workpiece reciprocating motion auxiliary axial flushing electrolytic wire cutting processing method;

Fig. 3 is a flow field model diagram when workpiece reciprocating motion assists axial flushing electrolytic wire cutting;

Figure 4 is the cloud diagram of the flow velocity distribution when the workpiece has no reciprocating motion (spacing is 0.1mm);

Figure 5 is a cloud diagram of the flow velocity distribution when the workpiece reciprocates along the feeding direction and the spacing increases to 0.2 mm;

Figure 6 is a cloud diagram of the flow velocity distribution when the workpiece reciprocates along the feeding direction and the spacing increases to 0.3 mm;

Figure 7 is a cloud diagram of the flow velocity distribution when the workpiece reciprocates along the axial direction of the wire electrode and moves upward by 1 mm;

Figure 8 is a cloud diagram of the flow velocity distribution when the workpiece reciprocates along the axial direction of the wire electrode and moves downward by 1mm;

The label names are: 1, pulse power supply, 2, industrial computer, 3, motion control card, 4, machine tool column, 5, circulation pipeline, 6, pressure pump, 7, filter, 8, liquid storage tank, 9, Electrolyte tank, 10, Cathode fixture, 11, Electrolyte, 12, Anode fixture, 13, Machine tool table, 14, Wire electrode, 15, Guide, 16, Diversion cavity, 17, Nozzle, 18, Work piece, 19 , flow field.

Detailed ways

According to Fig. 1-2, the overall structure of a workpiece reciprocating motion-assisted axial flushing electrolytic wire cutting processing device proposed by the present invention mainly includes a five-axis machine tool system, an electrolyte circulation system, a pulse power supply 1, an anode system, a wire Electrode system; five-axis machine tool system includes X-axis table, Y-axis table, Z-axis table, Xʹ-axis table, Yʹ-axis table, machine table; Xʹ-axis of Xʹ-axis table is installed on Yʹ-axis table , the Yʹ axis of the Yʹ-axis table is installed on the Z-axis table, the Z-axis of the Z-axis table is installed on the Y-axis table, the Y-axis of the Y-axis table is installed on the X-axis table, and the X-axis table The X axis is installed on the machine tool table 13; the five-axis machine tool system also includes an industrial computer 2 and a motion control card 3; the anode system includes an anode fixture 12 and a workpiece 18; the workpiece 18 is installed in the anode fixture 12, and the anode fixture 12 is installed in the On the Xʹ axis worktable; the wire electrode system includes a cathode clamp 10, a wire electrode 14, a nozzle 17, a guide cavity 16, and a guide 15; the cathode clamp 10 is fixedly installed on the machine tool column 4; the wire electrode 14, the nozzle 17, the guide The flow chamber 16 and the guide 15 are coaxially installed in the cathode fixture 10 .

The motion of the five axes is regulated by the industrial computer 2 in a modular way through the motion control card 3; the feed modules of the X-axis and the Y-axis operate independently to control the joint movement of the X-axis and the Y-axis to drive the workpiece 18 and the wire electrode 14 The relative feed movement between them; the feed module of the Z axis runs independently, and controls the up and down movement of the Z axis to drive the workpiece 18 to reciprocate along the axial direction of the wire electrode 14; the feed modules of the Xʹ and Yʹ axes are connected to the X axis, Combined with the feed module of the Y axis, when the workpiece 18 performs relative feeding motion to the wire electrode 14, the joint motion of the Xʹ axis and the Yʹ axis is controlled to drive the workpiece 18 to reciprocate along the feeding direction.

The operation process of "a kind of workpiece reciprocating motion assisted axial flushing electrolytic wire cutting processing method and device" of the present invention is as follows:

Step 1. The wire electrode 14 is installed in the cathode fixture 10, and the workpiece 18 is installed in the anode fixture 12;

Step 2. Start the pressure pump 6, and adjust the pressure of the pressure pump 6 according to the actual processing conditions. The electrolyte 11 enters the diversion chamber 16 through the filter 7 and the circulation pipe 5, and then sprays out from the nozzle 17 along the axis of the line electrode 14. After entering the machining gap of the workpiece 18, it falls into the electrolyte tank 9, and finally flows back into the liquid storage tank 8;

Step 3, the workpiece 18 is connected to the positive pole of the pulse power supply 1, the wire electrode 14 is connected to the negative pole of the pulse power supply 1, the pulse power supply 1 is activated, and appropriate electrical parameters are set;

Step 4. The industrial computer 2 controls the joint movement of the X axis and the Y axis through the motion control card 3 to drive the relative feed movement between the workpiece 18 and the wire electrode 14; controls the up and down movement of the Z axis to drive the workpiece 18 along the wire electrode 14 axis Make reciprocating motion in the direction; when the workpiece 18 performs relative feeding motion to the wire electrode 14, the joint motion of the Xʹ axis and the Yʹ axis is controlled to drive the workpiece 18 to reciprocate along the feeding motion direction;

Step 5. After the processing is completed, the pulse power supply 1 and the pressure pump 6 are turned off, and the workpiece 18 is separated and cleaned.

In order to verify the beneficial effect of the workpiece reciprocating motion assisted axial flushing electrolytic wire cutting processing method proposed by the present invention, Fluent 15.0 software was used to simulate the flow field in the machining gap, and the simulation conditions were as follows: the diameter of the wire electrode 14 is 0.3mm , the thickness of the workpiece 18 is 5mm, the width of the processed slit is 0.5mm, the aperture of the nozzle 17 is 0.5mm, the distance from the upper surface of the workpiece 18 is 2mm, and the inlet pressure of the flushing liquid is 1MPa. The flow field simulation model in the machining gap is established as shown in Figure 3.

Figure 4 is a cloud diagram of the flow velocity distribution when the workpiece does not reciprocate. It can be seen from the figure that when the electrolyte 11 flows at a high speed along the axial direction of the wire electrode 14, since the gap between the wire electrode 14 and the workpiece 18 is 0.1 mm, the depth of the kerf 10mm, only a small part of the electrolyte 11 can enter into the narrow and deep processing gap, and the flow speed is greatly reduced.

Figure 5 is the cloud diagram of the flow velocity distribution when the workpiece reciprocates along the feed direction and the gap increases to 0.2mm (the spacing increases by 0.1mm). It can be seen from Fig. 4 that as the distance between the wire electrode 14 and the workpiece 18 increases, a large amount of electrolyte 11 enters the machining gap and can reach the bottom of the slit. At the same time, the flow speed in the gap is relatively high, and the difference between the upper and lower flow speeds in the processing gap is not large.

Figure 7 is a cloud diagram of the flow velocity distribution when the workpiece reciprocates along the axial direction of the wire electrode and moves upwards by 1mm. Figure 8 is a cloud diagram of the flow velocity distribution when the workpiece 18 reciprocates along the axial direction of the wire electrode 14 and moves downward by 1mm. It can be seen that when the workpiece 18 reciprocates along the axial direction of the wire electrode 14, the flow velocity of the electrolyte 11 in the machining gap gradually changes as a whole, and the electrolyte 11 presents a pulsating flow state.

By simulating and comparing the flow field of the electrolyte 11 in the machining gap, it can be seen that the "workpiece reciprocating motion assisted axial flushing electrolytic wire cutting machining method and device" proposed by the present invention can speed up the elimination of electrolytic products in the machining gap and the electrolysis process. The update of liquid 11 improves the processing efficiency and processing accuracy of electrolytic cutting.

Claims (3)

1. A workpiece reciprocating motion assisted axial flushing electrolytic wire cutting machining method is characterized in that:

the workpiece is cut and machined by adopting an axial flushing electrolytic wire, the workpiece (18) reciprocates while the workpiece (18) performs feed cutting motion to the wire electrode (14), and the reciprocating motion of the workpiece (18) comprises the reciprocating motion of the workpiece (18) along the feed machining direction and the reciprocating motion of the workpiece (18) along the axial direction of the wire electrode (14);

when the workpiece (18) reciprocates along the feeding direction, the distance between the workpiece (18) and the wire electrode (14) changes periodically, and the distance between the workpiece and the wire electrode is increased instantly, so that the electrolyte (11) can enter the machining gap of the feeding end surface more and more smoothly, the electrolytic product can be thoroughly flushed away, the electrolyte (11) can be updated, the electrolytic reaction speed can be accelerated, and the electrolytic cutting machining efficiency can be improved; meanwhile, due to the increase of the machining gap of the feeding end face, the electrolyte (11) can rapidly flow through the machining gap, the on-way loss of the flow velocity of the electrolyte (11) is reduced, the flow velocity difference of the electrolyte (11) at the upper part and the lower part of the machining gap is reduced, and the machining precision of electrolytic cutting is improved;

when the workpiece (18) axially reciprocates along the line electrode (14), the distance between the workpiece (18) and the nozzle (17) is periodically changed, and the flow rate of the electrolyte (11) in the machining gap of the feeding end face is integrally and continuously changed, so that the electrolyte (11) in the machining gap of the front end presents a pulsating flow state, the elimination of an electrolysis product and the update of the electrolyte (11) are further accelerated, and the electrolytic cutting machining efficiency is improved; meanwhile, the electrolyte (11) adsorbed in the machined cutting seam can be thrown out under the action of inertia force, the flow field area (19) of the electrolyte (11) in the cutting seam is reduced, stray corrosion to the cut surface is reduced, and the machining precision of electrolytic cutting is improved.

2. The device for realizing the workpiece reciprocating motion assisted axial flushing electrolytic wire cutting machining method of claim 1 is characterized in that:

the system comprises a five-axis machine tool system, an anode system and a line electrode system;

the five-axis machine tool system comprises an X-axis workbench, a Y-axis workbench, a Z-axis workbench, an X ʹ -axis workbench, a Y ʹ -axis workbench and a machine tool workbench (13); an X ʹ shaft of an X ʹ shaft workbench is arranged on a Y ʹ shaft workbench, a Y ʹ shaft of a Y ʹ shaft workbench is arranged on a Z shaft workbench, a Z shaft of the Z shaft workbench is arranged on a Y shaft workbench, a Y shaft of the Y shaft workbench is arranged on an X shaft workbench, and an X shaft of the X shaft workbench is arranged on a machine tool workbench (13); the five-axis machine tool system also comprises an industrial personal computer (2) and a motion control card (3);

the anode system comprises an anode clamp (12) and a workpiece (18); the workpiece (18) is arranged in an anode clamp (12), and the anode clamp (12) is arranged on an X ʹ shaft workbench;

the wire electrode system comprises a cathode clamp (10), a wire electrode (14), a nozzle (17), a flow guide cavity (16) and a guider (15); wherein the cathode clamp (10) is fixedly arranged on the machine tool upright post (4); the wire electrode (14), the nozzle (17), the flow guide cavity (16) and the guider (15) are coaxially arranged in the cathode clamp (10).

3. The device for realizing the reciprocating motion assisted axial flushing electrolytic wire cutting machining method of the workpiece as claimed in claim 2, is characterized in that:

the feeding modules of the X-axis and the Y-axis operate independently, and the joint motion of the X-axis and the Y-axis is controlled to drive the relative feeding motion between the workpiece (18) and the wire electrode (14);

the feeding module of the Z shaft independently operates to control the up-and-down motion of the Z shaft to drive the workpiece (18) to reciprocate along the axial direction of the line electrode (14);

the feeding modules of the X ʹ shaft and the Y ʹ shaft are combined with the feeding modules of the X shaft and the Y shaft, and when the workpiece (18) makes relative feeding motion to the wire electrode (14), the joint motion of the X ʹ shaft and the Y ʹ shaft is controlled to drive the workpiece (18) to make reciprocating motion along the feeding motion direction.

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