CN107350970B

CN107350970B - ELID grinding wheel oxide film friction and wear online measurement, ELID grinding and polishing all-in-one machine

Info

Publication number: CN107350970B
Application number: CN201710332301.8A
Authority: CN
Inventors: 郐吉才; 江澄冉; 王江威; 李新; 邓小玲
Original assignee: Henan University of Technology
Current assignee: Henan University of Technology
Priority date: 2017-05-12
Filing date: 2017-05-12
Publication date: 2021-09-10
Anticipated expiration: 2037-05-12
Also published as: CN107350970A

Abstract

The invention provides an ELID grinding wheel oxide film friction coefficient online measurement, ELID grinding and polishing integrated machine, and belongs to the technical field of ELID grinding, friction coefficient measurement and ultra-precision polishing. The device integrates the functions of an oxide film online measurement function, an ELID grinding function and a polishing machine, can perform an ELID grinding experiment in real time on the basis of measured parameters, and simultaneously polishes a workpiece to be processed, so that the problem that errors are introduced by multiple clamping is avoided. The friction coefficient testing machine mainly comprises a friction coefficient testing machine part, an ELID grinding part and a polishing machine part. The invention integrates the real-time measurement of the oxide film, the ELID grinding and the polishing together, so that the measurement of the oxide film, the ELID grinding and the polishing are realized on one device, the real-time verification of the measured parameters of the oxide film is convenient, the errors caused by multi-station and multiple clamping are saved, the rough machining and the fine machining are integrated on one device, and the ultra-precision machining precision can be improved.

Description

ELID grinding wheel oxide film friction and wear online measurement, ELID grinding and polishing all-in-one machine

Technical Field

The invention belongs to the technical field of ELID grinding, frictional wear and ultra-precision polishing machines, and relates to an ELID grinding wheel oxide film frictional wear online measuring device and ultra-precision processing equipment which integrates ELID grinding wheel oxide film online measurement, ELID grinding and polishing and comprises an ELID grinding technology and is used for polishing materials at the same time.

Background

The purpose of the friction and wear test is to study the friction and wear phenomenon and the nature thereof, correctly evaluate the influence of various factors on the friction and wear performance, and determine the optimal parameters of the friction pair element meeting the use requirements. The contents of the friction and wear test research are very extensive, such as discussing the friction, wear and lubrication mechanism and various factors influencing the friction and wear, evaluating new wear-resisting, wear-reducing and friction materials and lubricants, and the like. Because the friction and wear phenomena are very complex, the friction and wear conditions are different, and the test methods and devices are various, how to accurately acquire the parameter change in the friction and wear process becomes a very important research subject. The friction and wear tester is a tester for testing friction and wear performance of materials and lubricants under given conditions. Therefore, in domestic research, many studies have been made by using a friction wear tester such as a roller type, a plunge type, or a disc pin type.

The ELID grinding technology is widely used for ultra-precise grinding of materials difficult to machine, the grinding precision and the surface quality are far higher than those of the traditional grinding technology, and the ELID grinding technology can achieve very high grinding precision and is closely related to an oxide film generated after the surface of the grinding wheel is electrolyzed. The oxide film has a series of functions of absorbing vibration, isolating a grinding wheel matrix, reducing grinding depth, assisting in polishing and grinding a surface and the like, so that an ELID grinding technology is more suitable for ultra-precise grinding than a traditional grinding technology, and higher surface quality can be achieved. Therefore, the measurement of the oxidation film friction coefficient is significant, and plays an important role in the processing precision and the surface quality. This has been described mainly in this paper, ELID grinding wheel oxidation film friction and wear on-line measurement, ELID grinding, polishing integrated machine.

The device integrates the ELID grinding wheel oxide film frictional wear online measurement function, the ELID grinding function and the polishing machine function, the ELID grinding experiment can be carried out in real time on the basis of measured parameters, meanwhile, the polishing treatment is carried out on a processed workpiece, and the problem that errors are introduced by multiple clamping is avoided.

Disclosure of Invention

The invention aims to provide a friction and wear test method for an ELID oxide film, which is characterized in that an ELID electrode system is additionally arranged on a friction and wear test machine, so that an ELID oxide film friction and wear test can be performed in addition to a conventional friction and wear test, and an ELID grinding function and a polishing machine function are added. The technical solution of the invention is as follows: an ELID grinding wheel oxide film friction and wear online measurement, ELID grinding and polishing integrated machine. The device mainly comprises a friction wear testing machine part, an ELID grinding part and a polishing machine part. The friction wear testing machine is shown in figure 1 and mainly comprises a working table, a fixing support, a sensor, a lever system, a loading system, a rotating cup, an ELID electrolysis system, a driving system and a motor, wherein a frequency converter and a three-phase asynchronous motor are used as a power system, and power is transmitted to a main shaft through a V belt and a belt wheel so as to drive the rotating cup which is connected with the main shaft and is used for fixing a lower test piece to rotate. And the lower test piece is fixed in the rotating cup by adopting a common one-side two-pin method, so that the lower test piece and the main shaft synchronously rotate. And forming a friction pair between the lower test piece and the upper test piece. An ELID electrolysis system is additionally arranged on the revolving cup and comprises a cathode, an anode (grinding wheel), a power supply and electrolyte. The loading system comprises a tray, weights, an arc nut and an upper test piece. The outer part of the bottom end of the tray rod is provided with threads, and a test piece on the sphere can be fixed by a special nut with the inner part in an arc shape. The lever system comprises a long rod, a short rod and a gasket. The short bar may be fixed to the bracket on the rear side table with 12 self-tapping screws, and the screws are symmetrical with respect to the long bar and the short bar. Make a screw hole that leads to apart from stock left end department to pass a screw and be used for touching the sensor, therefore can adjust stock distance sensor's distance length because the screw can rotate in the hole, thereby adapt to different sensors, the right-hand member of stock passes in a adapter sleeve, adopt interference fit between them, thereby can let the frictional force between the upper and lower test piece pass on the pole rethread pole passes the sensor, realize the coefficient of friction of ELID electrolytic grinding wheel oxide film, the wearability on-line measurement.

The ELID grinding section includes a power supply, an anode (grinding wheel), a cathode, and a nozzle. Referring to fig. 3, the power source used in the ELID electrode system is an ELID mirror grinding high frequency pulse power source. After the input three-phase alternating current passes through the ground wire isolation transformer, the direct-current working voltage is obtained through rectification and filtering. Then, the direct current pulse with adjustable pulse width and pulse interval is converted by a digital square wave generator, an analog switch driving circuit and a field effect transistor and is transmitted to the anode of the metal bond grinding wheel and the flat plate electrode at the nozzle. The external operation panel of the pulse power supply is provided with adjusting devices such as output voltage, pulse width, pulse interval and the like. The anode structure is shown in figure 4 and mainly comprises the following components: the insulation knob, the metal screw rod, the positive pole brush, insulating cover and binding screw. The cathode is connected with the negative pole of the power supply, and the cathode material of the invention is red copper. It is copper containing a certain amount of oxygen and is also called oxygen-containing copper. The copper here is required to be of high purity in order to have good electrical conductivity. Because of the inactivity of copper, the cathode red copper does not participate in electrolytic oxidation-reduction reaction and is not consumed. The design of the nozzle is shown in figure 5. Because the ELID power supply is in contact with the testing machine, the ELID power supply must be insulated from the safety aspect, and the uncharged core of the workbench is to ensure the insulation between the workpiece and the rotating cup. Therefore, a layer of thermosetting plastic is arranged between the lower test piece and the rotating cup, the inner wall of the rotating cup is coated with insulating paint, two positioning pins are sleeved with insulating plastic caps, and the inner wall of the liquid discharge hole is also coated with insulating paint. Because the upper test piece is electrified, and the upper test piece and the loading system are integrated, the loading system is also electrified. And (4) integrally insulating the loading system. The specific measure is that insulating paint is coated on the outer part of a long shaft of the loading system, and an insulating plastic pad is added when the long shaft is in interference fit with an upper weight tray. The connecting part of the lever and the loading system is in clearance fit, the right end of the lever is coated with insulating paint, and an insulating plastic pad is placed in the lever and the lever when the lever and the loading system are matched.

If an ELID grinding function is to be realized, an upper test piece in a special nut at the bottom end of a tray rod of a loading system needs to be replaced by a workpiece to be ground, a lower test piece in a rotating cup needs to be replaced by an iron-based diamond grinding wheel, the anode is connected with a carbon brush, the cathode is connected with red copper, the anode carbon brush is connected with the grinding wheel, and the cathode red copper is positioned above the grinding wheel to keep a certain gap. Electrolyte is injected into the gap through the nozzle to form an environment required by electrolysis, and an oxide film is formed. In the grinding process, the continuous finishing of the surface oxide layer of the metal bond grinding wheel and the electrolytic inhibition effect of the passive film are dynamically balanced by utilizing the nonlinear electrolytic finishing effect. Thereby obtaining an oxide layer with stable thickness, leading the abrasive particles of the grinding wheel to obtain constant edge height and good chip containing space, and realizing stable, controllable and optimal grinding process.

If the function of the polishing machine is to be realized, an upper test piece in a special nut at the bottom end of a tray rod of the loading system needs to be replaced by a workpiece to be polished, a lower test piece in a revolving cup needs to be replaced by a polishing disk, electrolyte needs to be replaced by polishing liquid, rough polishing can be carried out at the moment, and a polishing damage layer is removed. And a passivation film which has certain thickness and elasticity and contains the falling abrasive is formed on the surface of the grinding wheel in the ELID grinding, so that the grinding wheel becomes a good flexible polishing agent, can be finely ground by utilizing an oxide film after rough polishing, is used for removing surface layer damage generated by the rough polishing, and is further precisely polished to obtain excellent surface quality.

The technical scheme of the invention has the following beneficial effects:

1. the ELID grinding wheel oxide film friction and wear online measurement, ELID grinding and polishing integrated machine is a device for firstly providing oxide film online measurement, and can efficiently and accurately measure the friction performance of the ELID grinding wheel oxide film.

2. The device can obtain the real-time change rule of the oxide film, and has guiding significance for improving ELID electrolysis parameters and grinding parameters;

3. the device integrates an ELID grinding function, can carry out real-time grinding according to measured parameters, and verifies the reasonability of the parameters;

4. the device has integrateed the burnishing machine function, can carry out real-time polishing to the test piece after the grinding, has realized the better transition of ELID grinding, polishing, avoids clamping error to introduce by clamping many times.

Drawings

FIG. 1 is a schematic structural view of a friction and wear tester according to the present invention

FIG. 2 is a schematic view of the loading system and lever system of the present invention

FIG. 3 is a schematic view of the ELID grinding part structure of the present invention

FIG. 4 shows an anode brush and attachment structure according to the present invention

FIG. 5 is a design view of a nozzle in the present invention

In the figure: 1. the device comprises a workbench, 2. a fixed support, 3. a sensor, 4. a lower test piece, 5. a revolving cup, 6. a motor, 7. a small belt wheel, 8. a large belt wheel, 9. a main shaft, 10. a bearing seat, 11. a tray, 12. a weight, 13. an arc nut, 14. an upper test piece, 15. a long rod, 16. a short rod, 17. a gasket, 18. a connecting sleeve, 19. an anode, 20. a cathode, 21. a nozzle, 22. a power supply, 23. an insulating knob, 24. a wiring screw, 25. a metal screw, 26. an insulating sleeve and 27. an anode brush.

The specific implementation scheme is as follows:

for a further understanding of the contents, features and effects of the present invention, the following examples are illustrated in the accompanying drawings and described in the following detailed description:

the first embodiment is as follows: if an ELID grinding wheel oxide film frictional wear on-line measurement, ELID grinding and polishing integrated machine is used for carrying out a common frictional wear experiment, as shown in figure 1, a frictional wear, ELID grinding and polishing integrated machine fixing device comprises a workbench 1, a fixing support 2, a sensor 3, a lever system, a loading system, a rotating cup 5, a driving system and a motor 6. The driving system comprises a motor 6, a small belt wheel 7, a large belt wheel 8, a main shaft 9 and a bearing seat 10 which are connected in sequence. The main shaft 9 and the rotating cup 5 are positioned through bosses and connected through four bolts, and the lower test piece 4 can be positioned on the rotating cup 5 through a plane and two pins. The rotating motion of the driving system drives the rotating cup 5 to form a friction pair between the lower test piece 4 and the upper test piece 14.

As shown in fig. 2, the loading system includes a tray 11, a weight 12, an arc nut 13, and an upper test piece 14. The bottom end of the tray rod is externally provided with threads, and a test piece 14 on the sphere can be fixed by a special nut 13 with an arc-shaped inner part. The lever system comprises a long rod 15, a short rod 16 and a gasket 17. The short bar 16 may be fixed to a bracket on the rear side table with 12 self-tapping screws, and the screws are symmetrical with respect to the long bar 15 and the short bar 16. Make a screw hole that leads to apart from stock 15 left end department to pass a screw and be used for touching the sensor, therefore can adjust stock 15 distance sensor 3's distance length because the screw can rotate in the hole, thereby adapt to different sensor 3, stock 15's right-hand member passes in a adapter sleeve 18, adopt interference fit between them, thereby can let the frictional force between the upper and lower test piece pass on the pole rethread pole passes sensor 3, thereby carry out the frictional wear experiment.

Example two: if the eld grinding wheel oxide film friction wear is used for online measurement, and the eld grinding and polishing integrated machine is used for testing the friction wear of the eld oxide film, an eld electrode system is required to be additionally arranged on the right side of the rotating cup 5 on the basis of the first embodiment, and the eld electrode system comprises an anode 19 (grinding wheel), a cathode 20, a nozzle 21 and a power supply 22. As shown in fig. 4, the anode 19 is composed of an insulating knob 23, a metal screw 25, an anode brush 27, an insulating sleeve 26 and a binding screw 24. The cathode 20 material and the negative electrode of the power supply 22 are connected by adopting red copper. The power supply 22 draws current along an external circuit through the anode 19 into the cell. The electrons move in the opposite direction to the current, and leave the anode 19 under the action of an external power source, and flow to the cathode 20 through an external circuit. The anode 19 always appears electron-deficient due to electron flow, so that an oxidation process for releasing electrons is carried out thereon to form an oxide film on the grinding wheel, and ELID grinding can be carried out when an ELID system is added and the lower test piece is a diamond grinding wheel, so as to study the frictional wear performance of the oxide film of the grinding wheel.

Example three: if ELID grinding wheel oxide film friction wear is used for online measurement, an ELID grinding and polishing integrated machine is used for carrying out an ELID grinding experiment, on the basis of the embodiment 2, the upper test piece 14 is replaced by a substitute machining material, and the lower test piece 4 is replaced by a corresponding diamond grinding wheel, so that ELID grinding can be carried out.

Example four: if ELID grinding wheel oxide film friction wear is used for online measurement, an ELID grinding and polishing integrated machine realizes a polishing function, the lower test piece 4 in the rotating cup is replaced by a polishing disc on the basis of embodiment 3, electrolyte is replaced by polishing liquid, rough polishing can be carried out at the moment, and a grinding damage layer is removed. And an oxide film which has certain thickness and elasticity and contains the falling abrasive is formed on the surface of the grinding wheel in the ELID grinding, so that the grinding wheel becomes a good flexible polishing agent, the oxide film can be used for carrying out accurate grinding after rough grinding, the surface damage generated by rough grinding can be removed, the grinding wheel can be further precisely polished, and the excellent surface quality can be obtained.

Claims

1. An ELID grinding wheel oxide film friction coefficient on-line measurement, ELID grinding and polishing integrated machine is characterized by comprising a workbench (1), a fixed support (2), a sensor (3), a lever system, a loading system, a rotating cup (5), a driving system and a motor (6); the driving system comprises a motor (6), a small belt wheel (7), a large belt wheel (8), a main shaft (9) and a bearing seat (10) which are connected in sequence; the main shaft (9) and the rotating cup (5) are positioned through bosses and connected through four bolts, and the lower test piece (4) is positioned on the rotating cup (5) through a pin on one side and two pins on the other side; the rotary motion of the driving system drives the rotating cup (5) to form a friction pair between the lower test piece (4) and the upper test piece (14);

the loading system comprises a tray (11), a weight (12), an arc nut (13) and an upper test piece (14); the outer part of the bottom end of the tray rod is provided with threads, and a special nut (13) with the inner part in an arc shape is used for fixing a test piece (14) on the sphere; the lever system comprises a long lever (15), a short lever (16) and a gasket (17); the short rod (16) is fixed on a bracket on the rear side workbench by 12 self-tapping screws, and the screws are symmetrical about the long rod (15) and the short rod (16); a through threaded hole is drilled at the left end of the long rod (15), a screw penetrates through the threaded hole to touch the sensor, the screw rotatably adjusts the distance between the long rod (15) and the sensor (3) in the threaded hole so as to adapt to different sensors (3), the right end of the long rod (15) penetrates through a connecting sleeve (18), and the long rod and the threaded sleeve are in interference fit;

an ELID electrode system is additionally arranged on the right side of the revolving cup (5), and comprises an anode (19), a cathode (20), a nozzle (21) and a power supply (22); the anode (19) consists of an insulating knob (23), a metal screw rod (25), an anode brush (27), an insulating sleeve (26) and a wiring screw (24); the cathode (20) material and the negative electrode connecting material of the power supply (22) adopt red copper; the current of the power supply (22) enters the electrolytic cell through the anode (19) along an external circuit; the lower test piece is a diamond grinding wheel;

if the ELID grinding wheel oxide film friction wear is used for online measurement, an ELID grinding and polishing integrated machine is used for carrying out an ELID grinding experiment, the upper test piece (14) is replaced by a material to be processed, and the lower test piece (4) is replaced by a diamond grinding wheel;

if the ELID grinding wheel is used for online measurement of the frictional wear of the oxide film, the ELID grinding and polishing integrated machine realizes the polishing function, the lower test piece (4) in the rotating cup is replaced by a polishing disc, and the electrolyte is replaced by polishing liquid.