CN112372001A

CN112372001A - Electric field auxiliary processing machine tool and processing method for iron-based material

Info

Publication number: CN112372001A
Application number: CN202011219929.5A
Authority: CN
Inventors: 张国庆; 王建鹏; 周梦华; 陈燕冰; 罗通; 姜建凯
Original assignee: Shenzhen University
Current assignee: Shenzhen University
Priority date: 2020-11-04
Filing date: 2020-11-04
Publication date: 2021-02-19
Anticipated expiration: 2040-11-04
Also published as: CN112372001B

Abstract

The iron-based material electric field auxiliary processing machine tool comprises a main shaft, an installation part, a diamond cutter and a power supply device, wherein the diamond cutter is installed on the main shaft, the main shaft drives the diamond cutter to rotate, the installation part is opposite to the main shaft and used for installing a workpiece, and the power supply device is used for supplying variable current to the workpiece so as to enable electrons in the workpiece to be in a disordered state. According to the electric field auxiliary processing machine tool and the processing method for the iron-based material, the power supply device is arranged to supply the workpiece with the variable current, so that electrons in the workpiece are in a disordered state, and the pairing and combination of the electrons are inhibited, so that the aim of inhibiting the graphitization of the diamond cutter is fulfilled.

Description

Electric field auxiliary processing machine tool and processing method for iron-based material

Technical Field

The invention belongs to the field of iron-based material processing, and particularly relates to an electric field auxiliary processing machine tool and an electric field auxiliary processing method for an iron-based material.

Background

The affinity of the iron-based material and the carbon element is extremely strong, so when the diamond cutter is used for cutting a workpiece made of the iron-based material, the diamond cutter can be catastrophically worn, the cutting edge of the diamond cutter cannot keep the original sharpness, and the optical-grade surface roughness cannot be processed, so that the high processing cost is brought to ultra-precision processing, and the iron-based material cannot be replaced by turning instead of grinding. In order to inhibit the abrasion of the diamond cutter, the current processing auxiliary scheme comprises the means of workpiece surface nitriding, diamond cutter ion implantation, ultrasonic vibration assistance and the like.

Firstly, nitriding the surface of a workpiece, wherein in the nitriding process, nitrogen and unpaired d electrons in iron can generate bonding to form a compound, so that the affinity of the iron and carbon is reduced, and the catalytic action of an iron-based material on the graphitization of the diamond cutter is weakened. In order to obtain a nitriding layer with a stable thickness in a micron level, the workpiece surface nitriding scheme mostly adopts an ion nitriding process, which is beneficial to obtaining the surface roughness of an optical level mirror surface in ultra-precision machining. Although the surface nitriding process can be adopted to realize the workpiece processing surface roughness Ra less than 10nm, the ultra-precision processing precision is influenced by the uneven thermal deformation of the workpiece caused by the high temperature in the nitriding process and the complexity and unevenness of a nitriding layer, and the abrasive particle abrasion and the tipping of the diamond cutter are increased by nitride hard spots in the nitriding layer.

And secondly, ion implantation of the diamond cutter, wherein the ion implantation process of the diamond cutter is originated from impurity elements in a natural diamond cutter, which can influence the graphitization of diamond, so that a diamond element implantation scheme is created. In the aspect of selecting implanted elements, nitrogen ions are implanted into the diamond cutter to process steel, and experimental results show that the wear resistance of the cutter can be obviously improved. The chromium ion implantation diamond cutter is used for processing carbon steel, but the abrasion of the cutter is increased. The surface roughness below 10nm can be obtained by adopting the gallium ion implantation diamond cutter to process the iron-based alloy, the diamond cutter is not obviously abraded, but the processing distance is only 50m, and long-distance cutting cannot be carried out. Similar to the material surface nitriding principle, the essence of the diamond cutter ion injection scheme is also to reduce the affinity of iron element and carbon element and weaken the catalytic action of iron-based materials on diamond graphitization. The ion implantation process can cause permanent damage to the diamond lattice structure, affect the hardness property of the diamond, and therefore have a negative effect on the aspect of ultra-precision machining precision.

The ultrasonic vibration assisted cutting is a special cutting technology which vibrates at high speed along the cutting direction, and the test of cutting steel materials shows that the ultrasonic vibration assisted diamond cutting ferrous metal obviously reduces the abrasion of the diamond cutter and improves the surface quality of a workpiece. However, diamond tool wear is only somewhat reduced and not completely inhibited, and evidence of diamond graphitization and chipping remains with longer cutting times or distances.

Although the three schemes inhibit the abrasion of the iron-based material cut by the diamond cutter to a certain extent, the inhibition effect is still unsatisfactory, the three schemes cannot be applied to long-distance cutting, complex process requirements and expensive equipment are required, and the cost is high.

Disclosure of Invention

The invention aims to provide an electric field auxiliary processing machine tool and a processing method for iron-based materials, which can better inhibit graphitization of diamond tools, have low cost and simple process requirement and can be applied to long-distance cutting.

In order to realize the purpose of the invention, the invention provides the following technical scheme:

in a first aspect, the invention provides an iron-based material electric field auxiliary processing machine tool, which comprises a main shaft, a mounting part, a diamond tool and a power supply device, wherein the diamond tool is mounted on the main shaft, the main shaft drives the diamond tool to rotate, the mounting part is opposite to the main shaft, the mounting part is used for mounting a workpiece, and the power supply device is used for introducing variable current to the workpiece so as to enable electrons in the workpiece to be in a disordered state.

In one embodiment, the auxiliary processing machine tool for the electric field of the iron-based material further comprises an insulating sleeve, wherein the mounting part is arranged on the insulating sleeve, and the insulating sleeve is used for sleeving the periphery of the workpiece to insulate the workpiece and the mounting part.

In one embodiment, the electric field auxiliary processing machine tool for iron-based materials further comprises a controller, and the controller controls the intensity and the direction of the current output by the power supply device.

In one embodiment, the frequency of the current is equal to or greater than 50 hertz.

In one embodiment, the electric field auxiliary processing machine tool for the iron-based material further comprises a resistor, wherein the resistor is used for being connected with the workpiece in series to increase the resistance of a circuit.

In a second aspect, the present invention further provides an electric field assisted processing method for an iron-based material, where the electric field assisted processing method for an iron-based material includes:

mounting a diamond cutter on a main shaft;

mounting a workpiece on a mounting piece, and aligning the workpiece with the diamond cutter;

introducing variable current to the workpiece through a power supply device so as to enable electrons in the workpiece to be in a disordered state;

and relatively moving the workpiece and the rotating diamond tool to finish cutting.

In one embodiment, mounting a workpiece on a mount and aligning the workpiece with the diamond tool comprises:

and arranging an insulating sleeve on the mounting part, and extending the workpiece into the insulating sleeve to insulate the workpiece from the mounting part.

In one embodiment, passing a varying current through the workpiece via a power supply device to perturb electrons in the workpiece comprises:

and arranging a controller, and controlling the intensity and the direction of the current output by the power supply device through the controller.

In one embodiment, a controller is provided and controls the intensity and direction of the current output by the power supply device via the controller, comprising:

and controlling the power supply device to output current with the frequency of more than 50 Hz through the controller.

and arranging a resistor and connecting the resistor and the workpiece in series to increase the resistance of the circuit.

According to the electric field auxiliary processing machine tool and the processing method for the iron-based material, the power supply device is arranged to supply the workpiece with the variable current, so that electrons in the workpiece are in a disordered state, and the pairing and combination of the electrons are inhibited, so that the aim of inhibiting the graphitization of the diamond cutter is fulfilled.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic perspective view of an electric field assisted machining tool for iron-based materials with workpieces mounted thereon according to an embodiment of the present invention;

FIG. 2 is a schematic perspective view of a workpiece according to one embodiment;

FIG. 3 is a schematic front view of the workpiece of FIG. 2;

FIG. 4 is a schematic perspective view of the headstock and the spindle of FIG. 1;

FIG. 5 is a perspective view of the mount, insulating sleeve and workpiece of FIG. 1;

FIG. 6 is a schematic perspective view of the workpiece and insulating sleeve of FIG. 1;

FIG. 7 is a flow chart of an electric field assisted machining method for ferrous materials according to an embodiment of the present invention;

FIG. 8 is a schematic illustration of the effect of different current states on the electronic state in a conductor.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

Referring to fig. 1, an embodiment of the invention provides an electric field auxiliary processing machine 100 for iron-based materials, where the electric field auxiliary processing machine 100 for iron-based materials can be a grinding machine, a drilling machine, a milling machine, etc. The machine 100 is preferably a lathe for turning a workpiece 200 of ferrous material to obtain a desired product profile and accuracy. The electric field auxiliary processing machine 100 for iron-based materials includes a spindle 10, a mounting member 20, a diamond cutter (not shown), and a power supply device (not shown). The diamond cutter is installed on the main shaft 10, and the main shaft 10 drives the diamond cutter to rotate. The mount 20 is opposite to the spindle 10, and the mount 20 is used to mount the workpiece 200. The power supply device is used for supplying variable current to the workpiece 200 so as to enable electrons in the workpiece 200 to be in a disordered state.

Specifically, the electric field auxiliary processing machine 100 for iron-based materials further includes a main spindle box 30, a first machine table 41, a second machine table 42, and a moving table 43. The head stock 30 is rotatably connected to the main spindle 10, and a driving mechanism (not shown) for driving the main spindle 10 to rotate is provided in the head stock 30. The headstock 30 is slidably attached to the first table 41 and is movable in the X direction relative to the first table 41. The moving table 43 is slidably connected to the second table 42 and can move along the Z-direction relative to the second table 42. The mounting member 20 is movably coupled to the movable stage 43 and is movable in the X-direction relative to the movable stage 43. In addition, the mount 20 has a plurality of mounting positions in the Y direction, and the workpiece 200 can be mounted at any mounting position.

It can be understood that, in the ordinary cutting, applying current to the rotating workpiece 200 is easy to generate contact vibration, which will affect the machining precision, and the contact problem between the electrode and the rotating workpiece 200 is not easy to guarantee and will generate great loss to the electrode in the rotating contact friction process, once the contact is worn, the uncontrollable factors such as poor contact, current breaking, etc. will be caused. Therefore, the diamond cutter of the embodiment of the invention is installed on the main shaft 10, and the workpiece 200 is installed on the installation member 20, thereby preventing the workpiece 200 from rotating at a high speed and improving the cutting reliability. Meanwhile, in order to prevent the wire electrically connected to the workpiece 200 on the side close to the diamond tool from being cut by the diamond tool during cutting, optical-level mirror finishing may be performed on the side of the workpiece 200 opposite to the wire by controlling the fly-cutting trajectory. Referring to fig. 2, the workpiece 200 is provided with an energizing portion 210, and the energizing portion 210 protrudes out of the outer periphery of the workpiece so as to be in contact with the conductive wire. Wherein, the conducting part 210 is provided with a through hole 2101, and the conducting wire can be fixedly connected with the conducting part 210 through the through hole 2101 to ensure the stability of the conduction. Referring to fig. 3, the side of the workpiece 200 opposite to the electrified portion 210 is cut along the fly-cutting trajectory 90 by the diamond tool, so that the diamond tool does not interfere with the wire during cutting, which is beneficial to improving the cutting reliability. The electrical part 210 in fig. 3 is only illustrated as being located at the upper side, and the position of the electrical part 210 can be adjusted according to different machining positions and specific positions of the diamond tool when machining is performed. The present invention is not limited to the specific structure of the workpiece 200, and in other embodiments, the workpiece 200 may be another structure for facilitating fly-cutting, or a wire may be attached to the outer periphery of the workpiece 200 only by an adhesive tape.

The power supply device is arranged to supply the workpiece 200 with variable current, so that electrons in the workpiece 200 are in a disordered state, and the pairing combination of the electrons is inhibited, so that the aim of inhibiting the graphitization of the diamond cutter is fulfilled. Moreover, due to the availability and low cost of the electric field, in the actual processing, the electric field assistance can be combined with other schemes, such as at least one of the scheme of nitriding the surface of the workpiece 200, the ion implantation of the diamond cutter and the ultrasonic vibration assisted cutting, so as to further improve the graphitization inhibition effect of the diamond cutter.

Referring to fig. 4, one end of the spindle 10 extends into the spindle box 30, and the other end of the spindle 10 is sequentially provided with a suction cup 11 and a cutter disc 12. The cutter head 12 is fixed by being attracted by the suction cup 11, and the cutter head 12 and the suction cup 11 rotate in synchronization. One side of the cutter disc 12, which is back to the sucker 11, is used for mounting a diamond cutter, the cutter disc 12 is provided with a plurality of cutter positions, and the diamond cutter can be mounted on the suitable cutter positions aiming at workpieces 200 with different sizes.

Referring to fig. 5 and 6, the electric field auxiliary processing machine 100 for iron-based materials further includes an insulating sleeve 30, and the insulating sleeve 30 is disposed on the mounting member 20. The insulating sheath 30 is used for sheathing the outer periphery of the workpiece 200 to insulate the workpiece 200 from the mounting member 20. Specifically, the insulating sheath 30 may be made of inorganic insulating materials such as mica, asbestos, ceramic, and glass, or organic insulating materials such as shellac, resin, rubber, cotton yarn, paper, hemp, and silk. The insulating sleeve 30 is fitted over the end of the workpiece 200 remote from the diamond tool. The mounting sleeve may be placed on the clamp 21 of the mounting member 20, and the workpiece 200 is inserted into the insulating sleeve 30 and then fixed by the clamp 21. The insulating sleeve 30 may be provided independently, and the insulating sleeve 30 is first put on one end of the workpiece 200, and the workpiece 200 and the insulating sleeve 30 are fixed to the fixture 20 by the jig 21. In some embodiments, the insulating sleeve 30 may also be an insulating material applied to the outer periphery of the workpiece 200. In other embodiments, the insulating sheath 30 may be formed by winding the insulating cloth around the outer circumference of the workpiece 200 for at least one turn. It can be understood that since the machine tool itself is charged, it is necessary to isolate the external current from the machine tool current, and the insulating sleeve 30 is provided to insulate the workpiece 200 from the mounting member 20, thereby improving the reliability of cutting.

Referring to fig. 1, the electric field auxiliary processing machine 100 for iron-based materials further includes a resistor (not shown). A resistor is used in series with the workpiece 200 to increase the circuit resistance. Specifically, in addition to resistors, capacitors, inductors, and the like can be connected in series or in parallel to the circuit to form the desired electric field. It will be appreciated that the workpiece 200 is often too large in cross-section relative to the wire, resulting in a ferrous material with very low resistance, especially excellent electrical conductivity. The resistance value of the circuit is increased by connecting the resistors in series in the loop, so that the occurrence of short circuit is avoided, and the electrical reliability is improved.

Referring to fig. 1, the electric field assisted machining tool 100 for iron-based materials further includes a controller (not shown). The controller controls the intensity and direction of the current output by the power supply device. The Controller may be a single chip, a Programmable Logic Controller (PLC), a microcomputer, or the like. The controller may be integrated into the computer of the machine tool itself. It will be appreciated that the controller may control only the intensity of the current, or only the direction of the current, or both. During the cutting process, the controller may change the current many times, for example, periodically change the current intensity, periodically change the current direction, etc., thereby controlling the power supply device to output the current of the type of alternating current, direct current with the current intensity changed, pulse current, etc. The controller is arranged so as to control the power supply device to output proper variable current, and a variable electric field with the best graphitization inhibition effect on the diamond cutter is favorably generated. Meanwhile, because the workpieces 200 with different sizes and different iron contents have different requirements on the changing electric field, a controller is arranged, and the controller controls the intensity and the direction of the current output by the power supply device, so that the workpiece 200 can be adapted to most workpieces 200 conveniently.

It will be appreciated that an important cause of the graphitized wear that occurs when the diamond tool cuts the workpiece 200 is the catalysis of the iron-based material, which accelerates the conversion of diamond to graphite and reduces its conversion activation energy. Under vacuum conditions, the temperature required for diamond graphitization is 1700K, but when iron is present, the diamond graphitization temperature only needs 1000-1100K. Therefore, the catalytic action of iron on diamond graphitization is weakened, and the method plays an important role in inhibiting diamond graphitization abrasion. The change of the electron flow state caused by the fluctuation of the current is called a disorder state, and the disorder state is an electron movement state which is required by us, and in this state, the conventional electron coordination binding can be inhibited. Referring to fig. 8, fig. 8 shows the effect of different current states on the electronic state in the conductor, and as can be seen from fig. 8, the square-wave pulse current, the sine-cosine waveform current and the sawtooth waveform current can make the electronic state in the conductor better present a disordered state. The square wave pulse current can make the electronic state in the conductor in an intermittent disorder state (the electrons are intermittently disordered) because the current of the square wave pulse current is intermittently changed. The sine-cosine waveform current and the sawtooth waveform current are changed constantly, so that the electronic state in the conductor can be in a fully disordered state (the electronic state is disordered at any moment) by the sine-cosine waveform current and the sawtooth waveform current. The current adopted by the embodiment is preferably one or a combination of square wave pulse current, sine-cosine waveform current and sawtooth waveform current, and the pattern of the current can cross the zero axis and can also be positioned on one side of the zero axis. In other embodiments, a current with a waveform such as a sharp pulse or a step wave, or a current with an irregular waveform can also be used. In particular, when a periodically changing waveform current is used, it is preferable that the frequency of the current is 50 hz or higher, and a high frequency current can generate a high frequency electric field, and is more effective in electron disturbance.

Referring to fig. 1 and fig. 7, an embodiment of the present invention further provides an electric field assisted processing method for an iron-based material, where the electric field assisted processing method for an iron-based material includes:

s101: mounting a diamond cutter on the main shaft 10;

s102: mounting the workpiece 200 on the mounting member 20, and aligning the workpiece 200 with the diamond tool;

s103: changing current is introduced into the workpiece 200 through a power supply device, so that electrons in the workpiece 200 are in a disordered state;

s104: the workpiece 200 and the rotating diamond tool are relatively moved to complete the cutting process.

In one embodiment, referring to fig. 5 and 7, S102: mounting the workpiece 200 on the mount 20 and aligning the workpiece 200 with the diamond tool, comprising:

s1021: an insulating sleeve 30 is provided on the mount 20 and the workpiece 200 is inserted into the insulating sleeve 30 to insulate the workpiece 200 from the mount 20.

By providing the insulating sheath 30, the insulating sheath 30 can insulate the workpiece 200 and the mounting member 20, which is advantageous for improving electrical reliability.

In one embodiment, referring to fig. 7, S103: the method for supplying variable current to the workpiece 200 by the power supply device to make the electrons in the workpiece 200 in a disordered state comprises the following steps:

s1031: and arranging a controller, and controlling the intensity and the direction of the current output by the power supply device through the controller.

The controller is arranged so as to control the power supply device to output proper variable current, and a variable electric field with the best graphitization inhibition effect on the diamond cutter is favorably generated. Meanwhile, because the workpieces 200 with different sizes and different iron contents have different requirements on the changing electric field, a controller is arranged, and the controller controls the intensity and the direction of the current output by the power supply device, so that the workpiece 200 can be adapted to most workpieces 200 conveniently.

In one embodiment, please refer to fig. 7 and fig. 8, S1031: the controller is arranged and controls the intensity and the direction of the current output by the power supply device through the controller, and the controller comprises:

s10311: the controller controls the power supply device to output current with frequency larger than 50 Hz.

Specifically, the current adopted in this embodiment is one or a combination of a square wave pulse current, a sine-cosine waveform current and a sawtooth waveform current, and the pattern thereof may cross the zero axis or may be located on one side of the zero axis. In other embodiments, a current with a waveform such as a sharp pulse or a step wave, or a current with an irregular waveform can also be used. The current which is larger than 50 Hz is output by the power supply device, so that the turbulence effect on electrons in the workpiece 200 is improved.

s1032: a resistor is provided and connected in series with the workpiece 200 to increase the resistance of the circuit.

The resistance value of the circuit is increased by connecting the resistors in series in the loop, so that the occurrence of short circuit is avoided, and the electrical reliability is improved.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. The utility model provides an iron-based material electric field auxiliary processing machine tool, its characterized in that includes main shaft, installed part, diamond cutter and power supply unit, diamond cutter installs on the main shaft, the main shaft drives diamond cutter rotates, the installed part with the main shaft is relative, the installed part is used for the installation work piece, power supply unit is used for doing the work piece lets in the electric current that changes, so that electron in the work piece is the disorderly state.

2. An electric field auxiliary processing machine tool for iron-based materials according to claim 1, further comprising an insulating sleeve provided on the mounting member, the insulating sleeve being adapted to fit around the outer periphery of the workpiece to insulate the workpiece from the mounting member.

3. An electric field assisted machine tool for processing ferrous materials as defined in claim 1, further comprising a controller for controlling the intensity and direction of the current output from said power supply.

4. An electric field assisted machine tool for processing ferrous materials as defined in claim 3 wherein the frequency of the current is 50 hz or higher.

5. An electric field assisted machine tool for ferrous materials as defined in claim 1 further including a resistor for series connection with said workpiece to increase the resistance of the circuit.

6. An electric field auxiliary processing method for an iron-based material is characterized by comprising the following steps:

mounting a diamond cutter on a main shaft;

7. An electric field assisted machining method for a ferrous material according to claim 6, wherein mounting a work piece on a mounting member and aligning the work piece with the diamond tool comprises:

8. An electric field assisted processing method for a ferrous material as defined in claim 6, wherein passing a varying current through a power supply means to the workpiece to cause the electrons in the workpiece to assume a disordered state comprises:

9. An electric field assisted machining method for a ferrous material according to claim 8, wherein a controller is provided and the intensity and direction of the current output from the power supply device are controlled by the controller, comprising:

10. An electric field assisted processing method for a ferrous material as defined in claim 6, wherein passing a varying current through a power supply means to the workpiece to cause the electrons in the workpiece to assume a disordered state comprises: