Reciprocating spin-printing electrolytic machining device and method
Technical Field
The invention provides a reciprocating spin-printing electrolytic machining device and method, and belongs to the field of electrolytic machining.
Background
The cartridge receiver is a large-scale thin-wall revolving body part, is one of core parts of an aeroengine, and is mostly machined by traditional numerical control milling at present, but the milling machining of the cartridge receiver generally has the problems of long machining period, high cutter cost, serious machining deformation and the like due to the thin wall of the cartridge receiver, the adoption of titanium alloy, nickel-based high-temperature alloy and other difficult-to-machine materials, and high material removal rate. In order to solve the processing problem of thin-wall case parts, Nanjing aerospace university provides a novel aero-engine thin-wall case electrolytic processing method (with the authorization number ZL201410547093.X, the Nanjing aerospace university of the applicant, the inventor: red silvergrass, Zhu great, Wang hongrui and Wang Deng Yong), the method (also called as a rotary printing electrolytic processing method) can realize one-time processing and forming of a complex profile by using a single rotary tool electrode, and has unique advantages for controlling the processing deformation of the thin-wall case.
The spin-printing electrolytic processing is to rapidly remove materials by utilizing electrochemical anodic dissolution. During machining, the workpiece anode and the tool cathode with the window on the surface rotate relatively at the same angular speed in a fixed direction, meanwhile, the tool cathode feeds to the workpiece anode at a certain feeding speed, electrolyte flows into a machining area from one side and flows out from the other side, along with the machining, the material of the workpiece anode is continuously dissolved, the diameter of the material is gradually reduced, and the surface of the workpiece anode corresponding to the cathode window is gradually machined into a boss structure. When the processing depth is large, the flow field distribution of a processing area can be influenced by a high boss structure on the surface of a workpiece, the flow velocity of electrolyte in a processing area on one side of a boss facing the liquid area is high, the dissolution amount of a material is large, the flow velocity of electrolyte in a processing area on one side of a boss back liquid area is low, dead water areas, vortexes and other phenomena exist locally, the dissolution amount of the material is relatively small, and therefore the phenomena of asymmetry of two sides of the boss, even local short circuit and the like can occur, and the stability and the forming precision of rotary printing electrolytic processing are influenced.
In order to meet the requirements of stability and forming precision of rotary printing electrolytic machining, a reciprocating type rotary printing electrolytic machining device and method are provided.
Disclosure of Invention
The invention aims to solve the problem of uneven dissolving amount of two sides of a high boss in large-depth rotary printing electrolytic machining, periodically changes the rotating directions of a workpiece anode and a tool cathode by adopting an electrode reciprocating type rotating and electrolyte reciprocating type liquid supplying method, changes the flow direction of electrolyte in a machining area along with the rotating directions, and realizes uniform dissolving of materials on two sides of the boss, and provides a reciprocating rotary printing electrolytic machining device and a method.
The reciprocating type rotary printing electrolytic machining device is characterized in that: the device comprises a one-way servo valve, a tool cathode, a clamp, a valve controller, a motion controller and a programmable power supply;
the clamp is of a symmetrical structure, a first inlet is arranged in the middle above the clamp, and a group of first outlets are arranged on two sides of the first inlet; a second inlet is arranged in the right middle below the clamp, and a group of second outlets are arranged on two sides of the second inlet;
a first inlet of the clamp is connected with an electrolyte main inlet through a first one-way servo valve, and a second inlet of the clamp is connected with an electrolyte main inlet through a second one-way servo valve; a first outlet of the clamp is connected with a main electrolyte outlet through a third one-way servo valve and a second outlet of the clamp is connected with a main electrolyte outlet through a fourth one-way servo valve; the electrolyte supply pressures of the first inlet and the second inlet are equal;
the tool cathode and the workpiece anode are both of circular structures and are arranged in the clamp; a groove is arranged on the cylindrical surface of the cathode of the tool;
the tool cathode is connected with the cathode of the programmable power supply, and the workpiece anode is connected with the anode of the programmable power supply;
the signal output end of the programmable power supply outputs a control signal to the signal input end of the motion controller, and the signal output end of the motion controller is respectively connected with the signal input ends of the clamp and the valve controller through signal wires;
and the signal output end of the valve controller is respectively connected with the input ends of the first one-way servo valve, the second one-way servo valve, the third one-way servo valve and the fourth one-way servo valve.
The processing method of the rotary printing electrolytic processing reversing liquid supply device is characterized by comprising the following steps:
step 1, starting a valve controller, keeping a first one-way servo valve, a second one-way servo valve, a third one-way servo valve and a fourth one-way servo valve in a fully-opened state, enabling electrolyte to flow through a machining area between a workpiece anode and a tool cathode, and gradually filling a clamp;
step 2, during processing, connecting the anode of the workpiece with the anode of a programmable power supply, connecting the cathode of the tool with the cathode of the programmable power supply, controlling the anode of the workpiece and the cathode of the tool in a fixture by a motion controller to rotate oppositely at the same angular speed, feeding the cathode of the tool at a constant speed along the direction of the connecting line of the anode of the workpiece and the cathode of the tool, continuously dissolving materials on the surface of the anode of the workpiece under the action of electrolysis, gradually processing a boss in a region corresponding to the groove on the surface of the cathode of the tool, and specifically processing according to the step 3;
step 3, rotating the workpiece anode clockwise, and rotating the tool cathode anticlockwise to be called forward rotation; the anode of the workpiece rotates anticlockwise, and the clockwise rotation of the cathode of the tool is called reverse rotation; opening the first one-way servo valve and the fourth one-way servo valve, closing the second one-way servo valve and the third one-way servo valve, and enabling the electrolyte to flow in from a first inlet on the front side of the processing area and flow out from a second outlet on the rear side of the processing area, wherein the electrolyte is called forward liquid supply; opening the second one-way servo valve and the third one-way servo valve, closing the first one-way servo valve and the fourth one-way servo valve, and leading the electrolyte to flow in from a second inlet at the rear side of the processing area and flow out from a first outlet at the front side of the processing area, wherein the process is called reverse liquid supply; setting t1 as the time for one forward rotation or one reverse rotation, and t2 as the time required by the stable flow of the electrolyte in the clamp; the specific processing process is as follows:
at the moment 0, the workpiece anode rotates forwards, liquid is supplied forwards, and the electrolyte in the area on the front side of the boss has higher flow rate when the boss of the workpiece anode is transferred into the processing area;
at the time t1, the programmable power supply stops outputting voltage, the workpiece anode and the tool cathode stop moving, and the valve controller switches the one-way servo valve;
at the time of t1+ t2, the electrolyte flows stably, the motion controller switches the rotating directions of the workpiece anode and the tool cathode, the output voltage is started, the reverse rotation and the reverse liquid supply are adopted, and the electrolyte in the boss rear area has higher flow rate when the boss of the workpiece anode is transferred into the processing area;
at the time of t1+ t2+ t1, the programmable power supply stops outputting voltage, the workpiece anode and the tool cathode stop moving, and the valve controller switches the one-way servo valve;
at the time t1+ t2+ t1+ t2, the electrolyte flows stably, the motion controller switches the workpiece anode and the tool cathode, the output voltage is started, and the step 3 is repeated.
The processing method using the reciprocating spin-printing electrolytic processing device is characterized in that: and if T is the time for the workpiece anode and the tool cathode to rotate for one circle, the time T1 for one forward rotation or one reverse rotation usually ranges from T < T1<2T, and the time T2 required by the stable flow of the electrolyte in the clamp usually ranges from 0.5s < T2<2 s.
The invention has the beneficial effects that:
(1) the invention adopts the electrode reciprocating rotation and electrolyte reciprocating liquid supply method, can eliminate the influence of phenomena such as dead water areas and vortexes behind the lug boss on the dissolution of materials on the two sides of the lug boss in the whole processing process, ensures that the electrolytes on the front side and the rear side of the lug boss on the surface of a workpiece have higher flow velocity in the processing process, and realizes the uniform dissolution of the materials on the two sides of the lug boss, thereby improving the contour symmetry degree of the lug boss, particularly the higher lug boss forming.
(2) According to the invention, a mode of linkage of a power supply, a motion controller and a valve controller is adopted, the output voltage is stopped and the flow direction of electrolyte is changed before the electrode steering is changed, the rotation direction of the electrode is changed after a flow field in a processing area is stabilized, and the processing is continued, so that the flow velocity of the electrolyte in the processing area can be ensured to be the same at all times; meanwhile, the inlet and the outlet of the clamp are of a completely symmetrical structure, and the design of 'small inlet in the middle and large outlet on two sides' is adopted, so that the high flow rate of the electrolyte flowing into the processing area is ensured, and the reaction products and bubbles can be quickly removed.
(3) According to the invention, the period of electrode turning is changed, and the time of electrode rotation by non-integer circles is adopted, so that the phenomenon of uneven material dissolution at the angle position caused by the fact that the electrode turning and the electrolyte flow direction are changed at the same angle due to signal delay and the like can be avoided, uniform dissolution of all parts of a workpiece is ensured, and the processing stability is improved.
Drawings
FIG. 1 is a schematic view of a reciprocating spin-printing electrolytic processing apparatus;
FIG. 2 is a schematic view of forward rotation of the electrode and forward liquid supply;
FIG. 3 is a schematic view of electrode inversion and reverse liquid supply;
the device comprises a first one-way servo valve 1, a second one-way servo valve 2, an electrolyte pipeline 3, an electrolyte pipeline 4, a workpiece anode 5, a first outlet 6, a first inlet 7, a boss 8, a tool cathode 9, a third one-way servo valve 10, a valve controller 11, an electric signal line 12, a motion controller 13, a programmable power supply 14, a fourth one-way servo valve 15, a second outlet 16, a second inlet 17 and a clamp.
Detailed Description
Embodiments of the reciprocating spin-printing electrolytic processing apparatus and method according to the present invention will be described in detail with reference to fig. 1 to 3.
As shown in fig. 1, a reciprocating spin-printing electrolytic machining device includes a one-way servo valve, a tool cathode, a clamp, a valve controller, a motion controller, and a programmable power supply; the clamp is of a symmetrical structure, a first inlet is arranged in the middle of the upper part of the clamp, and a group of first outlets are arranged on two sides of the first inlet; a second inlet is arranged in the right middle below the clamp, and a group of second outlets are arranged on two sides of the second inlet; a first inlet of the clamp is connected with a main electrolyte inlet through a first one-way servo valve, and a second inlet of the clamp is connected with a main electrolyte inlet through a second one-way servo valve; a first outlet of the clamp is connected with a main electrolyte outlet through a third one-way servo valve and a second outlet of the clamp is connected with a main electrolyte outlet through a fourth one-way servo valve; the electrolyte supply pressures of the first inlet and the second inlet are equal; the tool cathode and the workpiece anode are both of circular structures and are arranged in the clamp, and a groove is arranged on the cylindrical surface of the tool cathode; the tool cathode is connected with the cathode of the programmable power supply, and the workpiece anode is connected with the anode of the programmable power supply; the programmable power supply signal output end outputs a control signal to the signal input end of the motion controller, and the signal output end of the motion controller is respectively connected with the signal input ends of the clamp and the valve controller through signal wires; and the signal output end of the valve controller is respectively connected with the input ends of the first one-way servo valve, the second one-way servo valve, the third one-way servo valve and the fourth one-way servo valve.
As shown in fig. 2 and 3, the processing method using the reciprocating spin-printing electrolytic processing device includes the following processes:
step 1, starting a valve controller, keeping a first one-way servo valve, a second one-way servo valve, a third one-way servo valve and a fourth one-way servo valve in a fully-opened state, enabling electrolyte to flow through a machining area between a workpiece anode and a tool cathode, and gradually filling a clamp;
step 2, during processing, connecting the anode of the workpiece with the anode of a programmable power supply, connecting the cathode of the tool with the cathode of the programmable power supply, controlling the anode of the workpiece and the cathode of the tool in a fixture by a motion controller to rotate oppositely at the same angular speed, feeding the cathode of the tool at a constant speed along the direction of the connecting line of the anode of the workpiece and the cathode of the tool, continuously dissolving materials on the surface of the anode of the workpiece under the action of electrolysis, gradually processing a boss in a region corresponding to the groove on the surface of the cathode of the tool, and specifically processing according to the step 3;
step 3, rotating the workpiece anode clockwise, and rotating the tool cathode anticlockwise to be called forward rotation; the anode of the workpiece rotates anticlockwise, and the clockwise rotation of the cathode of the tool is called reverse rotation; opening the first one-way servo valve and the fourth one-way servo valve, closing the second one-way servo valve and the third one-way servo valve, and enabling the electrolyte to flow in from a first inlet on the front side of the processing area and flow out from a second outlet on the rear side of the processing area, wherein the electrolyte is called forward liquid supply; opening the second one-way servo valve and the third one-way servo valve, closing the first one-way servo valve and the fourth one-way servo valve, and leading the electrolyte to flow in from a second inlet at the rear side of the processing area and flow out from a first outlet at the front side of the processing area, wherein the process is called reverse liquid supply; setting t1 as the time for one forward rotation or one reverse rotation, and t2 as the time required by the stable flow of the electrolyte in the clamp; the specific processing process is as follows:
at the moment 0, the workpiece anode rotates forwards, liquid is supplied forwards, and the electrolyte in the area on the front side of the boss has higher flow rate when the boss of the workpiece anode is transferred into the processing area;
at the time t1, the programmable power supply stops outputting voltage, the workpiece anode and the tool cathode stop moving, and the valve controller switches the one-way servo valve;
at the time of t1+ t2, the electrolyte flows stably, the motion controller switches the workpiece anode and the tool cathode, the output voltage is started, reverse rotation and reverse liquid supply are adopted, and the electrolyte in the boss rear area has high flow rate in the process of transferring the boss of the workpiece anode into the processing area;
at the time of t1+ t2+ t1, the programmable power supply stops outputting voltage, the workpiece anode and the tool cathode stop moving, and the valve controller switches the one-way servo valve;
at the time t1+ t2+ t1+ t2, the electrolyte flows stably, the motion controller switches the workpiece anode and the tool cathode, the output voltage is started, and the step 3 is repeated.
And T is the time for rotating the workpiece anode (10) and the tool cathode (11) for one circle, the time T1 for one forward rotation or one reverse rotation usually ranges from T < T1<2T, and the time T2 required by the stable flow of the electrolyte in the clamp usually ranges from 0.5s < T2<2 s.